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... For example, rapeseed and sunflower oils are used as feedstock for biodiesel production in Europe; while soybean oil and coconut oil are used as feedstock for biodiesel production in the US and the Philippines, respectively [18,19]. However, the current focus of many studies on biodiesel has shifted towards the production of biodiesel from alternative feedstocks such as waste oils [20][21][22][23], grease [24], microalgae [25,26], seaweeds [27] and insect oil [28][29][30]. The major disadvantage of edible and nonedible crops is the fact that their use for biodiesel production threatens the global food and feed supply chain by placing a demand on the land used for agricultural purposes [31,32]. ...
... The fat body plays a major role in some of the insect body metabolisms, and serves as food and medicine for both man and animals [37,38]. Manzano-Agugliaro et al. [28] reported that the fat content of a large number of insect species ranges from 25% to 77%, and also suggested that the excess fat could be used for biodiesel production. Li et al. [29] studied the biodiesel potential of black soldier fly (BSF) larvae which were grown on 1 kg of chicken manure for 10 days, and observed that the fuel properties of the biodiesel from the BSF larvae, such as density (885 kg/m 3 ), viscosity (5.8 mm 2 s -1 ), ester content (97.2%), flash point (123 • C), and cetane number (53) were comparable to those of rapeseed-oil-based biodiesel. ...
... Despite the prospects of biodiesel production from insect feedstock [28,29,39,40], research on the production of biodiesel from M. nigeriensis has never been reported. Thus, considering that M. nigeriensis is one of the gregarious termites that are readily available in different parts of Nigeria and in a few other African countries [41], effort was made in this study to produce biodiesel from the insect in order to analyze its properties. ...
Article
The use of insects as feedstock for biodiesel production has sparsely been studied and very little is known of the fuel properties and engine performance of insect biodiesel. In this study, biodiesel was initially produced from an insect feedstock M. nigeriensis, then its physicochemical properties were characterized. The biodiesel was produced via the three-step process of lipid extraction, acid esterification (1 wt% H2SO4) and alkaline transesterification (0.5 wt% NaOH). The optimal reaction time, temperature and methanol-oil molar ratio for the acid-esterification process resulted in a free fatty acid conversion of 96.58%. The volumetric yield, fatty acid methyl esters content and physicochemical properties of M. nigeriensis biodiesel were analyzed using various analytical equipment such as the GC-HRMS, and ¹H NMR. Analysis of the production process showed that 86.54 vol% biodiesel was obtained from M. nigeriensis oil. Further analysis showed that the biodiesel contained 96.72% fatty acid methyl esters. The composition of the fatty acid methyl esters was found to be 48% saturated esters and 52% monosaturated esters. The biodiesel density (841 kg m⁻³), viscosity (2.32 mm² s⁻¹), flash point (125 °C), pour point (−15 °C), cetane number (51.4), higher heating value (41.8 MJ kg⁻¹) and acid value (0.44 mgKOH.g⁻¹) were in compliance with the ASTM D6751 standards. One of the important results to highlight is the remarkably low viscosity of the biodiesel, which is attributed to the high concentration of monounsaturated fatty acid methyl esters. Lower viscosity of fuel helps to improve fuel atomization and combustion efficiency, and hence lower emissions. The absence of polyunsaturated fatty acid esters also indicates that the biodiesel will have good oxidation stability.
... Hermetia illucens biowaste treatment has garnered increased attention over the last few decades [25,26]. The process consists of waste preprocessing, biowaste treatment by H. illucens larvae, separation of larvae from the process residue, and refinement of the larvae and residue into upcycled marketable products [27]. The whole process involves killing, cleaning, sterilising, drying, and fractionating (proteins, lipids, and chitin) followed by composting or anaerobic digestion [26]. ...
... The economical scale of technologies [11,12,27]-the supply chains for the input of waste and distribution of extracted products and frass for various industries are still lacking. For example, the processing of animal feed in one location and the sending of the frass to nearby farms and agricultural land may be a logistical challenge. ...
... Incomplete or restrictive local regulations on usage-Several countries have started allowing the use of H. illucens larvae for the production of feeds under certain strict conditions (registration, processing, animal specificity) [11]. However, some countries still prohibit its use as feeds for livestock that are meant for later consumption by humans [27]. Given the general novelty of this approach, there may be regions with blanket prohibitions on it from the lack of established guidelines. ...
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The negative impact of the modern-day lifestyle on the environment was aggravated during the COVID-19 pandemic through the increased use of single-use plastics from food take-aways to medical supplies. Similarly, the closure of food outlets and disrupted supply chains have also resulted in significant food wastage. As the pandemic rages on, the aggravation of increased waste becomes an increasingly urgent problem that threatens the biodiversity, ecosystems, and human health worldwide through pollution. While there are existing methods to deal with organic and plastic waste, many of the solutions cause additional problems. Increasingly proposed as a natural solution to man-made problems, there are insect solutions for dealing with the artificial and organic waste products and moving towards a circular economy, making the use of natural insect solutions commercially sustainable. This review discusses the findings on how some of these insects, particularly Hermetia illucens, Tenebrio molitor, and Zophobas morio, can play an increasingly important role in food and plastics, with a focus on the latter.
... Biodiesel is a promising nonfossil fuel, derived from renewable feedstock, such as vegetable oil or animal fat. This latter represents a more cost-efficient choice, if compared to the vegetable one, thus it is often preferred for the biodiesel conversion (Manzano-Agugliaro et al., 2012). Recently, insects have been proposed as a valid source of fat for biodiesel production, for its high content and production rate (Li et al., 2011). ...
... H. illucens fat has a high concentration of medium chain saturated fatty acids and a low concentration of polyunsaturated fatty acids, which potentially makes it an ideal substrate for producing high-quality biodiesel (Surendra, Olivier, Tomberlin, Jha, & Khanal, 2016). After lipids are extracted, the biodiesel production is accomplished by acid-catalyzed esterification of free fatty acids and alkaline-catalyzed transesterification (Manzano-Agugliaro et al., 2012). The obtained biodiesel is a mixture of mono-acyl esters of fatty acids, and so, its final quality is strictly correlated to the amount and type of esters which compose the insect lipid fraction (Manzano-Agugliaro et al., 2012). ...
... After lipids are extracted, the biodiesel production is accomplished by acid-catalyzed esterification of free fatty acids and alkaline-catalyzed transesterification (Manzano-Agugliaro et al., 2012). The obtained biodiesel is a mixture of mono-acyl esters of fatty acids, and so, its final quality is strictly correlated to the amount and type of esters which compose the insect lipid fraction (Manzano-Agugliaro et al., 2012). As a matter of fact, the insect lipid profile is highly variable and depends on the insect species, the life cycle stage and the substrate of growth. ...
Chapter
The complete valorization of wastes and by-products to new valuable commodities requires innovative, “out-of-the-box” technologies, also including biological technologies, which must be at the same time economically, socially, and environmentally sustainable. Inside this scenario, insects have been gaining a lot of momentum as a promising biotechnological solution for exploiting residual biomasses. The diversity of these residual biomasses constitutes a technological problem for processing, and insects may represent a possible biotechnological solution. Several insect species naturally develop on organic wastes and, via the incorporation of the nutrients into their bodies, can be used to reduce the amount of waste material, while at the same time generating a more homogeneous and more valuable biomass. As a matter of fact, insects are a good source of useful compounds, being rich in protein, fat, chitin, and micronutrients. These biomolecules can be used for different purposes (e.g., for feed/food ingredients, cosmetics, pharma, bioplastics, and others), actually upgrading the value of the starting waste. In this chapter the possibility to use insects as bioagents in the agro-food by-products management will be explored, outlining their potential role in a circular economy system.
... Insects represent approximately 60% of the global biodiversity, with more than one million species identified; however, it is thought that only 20% of the existing global biodiversity has been described [43,53], of which 2163 species have been identified, with more than 30% occurring in the neotropical region [46]. The large-scale culture of insects has been developed to produce silk, bait for fishing and animal feed, despite the complicated feed requirements and environmental conditions of different cultivated species [43], but their proposed uses are increasingly varied [30]. The practice of ingesting insects as a source of nutrients for humans, which is called entomophagy or anthropoentomophagy, is a familiar topic globally, as seen by the archaeological evidence from the analysis of fossilized faeces, which shows that humanity has evolved as an entomophagous species [38]; even tribal communities in India see insects as a genuine and valuable food [33]. ...
... However, there are radically different points of view on the perception of insect consumption, since, in some places, insects are an alternative food source for people in poverty, while in other countries they are used in elite cuisine [38,46]. Despite these differences, from a nutritional perspective, harnessing insects as food for humans is not an idea that should be discarded, since, according to various scientific studies, the good quality of insect proteins, in addition to the contribution of lipids, carbohydrates and certain vitamins, is evident when compared to animal sources [31,35,38,44,55] or vegetal sources [30]. Although there is high variability in the nutritional composition of edible insect species [36,42,53], the grasshopper Sphenarium purpurascens stands out due to its high content of highquality proteins and availability throughout the year [14,31,32,[37][38][39][40][41]51], although there is very little reliable scientific information about this insect. ...
... In different parts of the world, insects are consumed raw or are incorporated into various products ranging from salads to cookies; however, it is necessary to take into account that their nutritional composition may depend on various factors (mainly temperature) involved in their preparation for consumption [2]. Manzano-Agugliaro et al. [30] reviewed the available literature and established that the fat characteristics of some insect species during specific stages of their development make them a viable alternative for the production of biodiesel and use as a renewable source of protein and energy. Premalatha et al. [38] proposed the large-scale production of insects to obtain meals with high protein content to be used for animal consumption, which, in turn, produces protein for human consumption. ...
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The intake of insects by humans is not a new practice, but in some cultures, is still an insalubrious activity or even a taboo. Over time, eating some insect's species to obtain proteins seems to be a feasible idea to an economic, environmental and nutritional point of view. Among more than 2000 species of edible insects, the Sphenarium purpurascens stands out, due to its nutritional properties. A review of the intake of insects as a source of proteins was made, to integrate the information of S. purpurascens analyzing nutritional aspects to establish its potential to the food industry. The data found reveal that S. purpurascens has higher protein content than some conventional sources of animal origin, with an important contribution of fats, carbohydrates, minerals and their amino acid profile, it complies with the FAO requirements. All these characteristics offer a potential for processed foods development with high protein content and not only to encourage the consumption of the classic fried and spiced insect as it is currently consumed. However, studies that register officially the total production for their possible mass production and potential industrial uses are needed.
... BSF larvae have the potential to curb MSW generation. The most straightforward utilization of BSF larvae is as animal feed, and a number of researchers have investigated this application (Manzano-Agugliaro et al., 2012;Sánchez-Muros et al., 2014;Tschirner and Simon, 2015;Surendra et al., 2016;Hussein et al., 2017;Su et al., 2019;Wynants et al., 2019). BSF larvae can also produce biodiesel through fat processing and biologically active substances (Li et al., 2011;Manzano-Agugliaro et al., 2012;Surendra et al., 2016;Su et al., 2019). ...
... The most straightforward utilization of BSF larvae is as animal feed, and a number of researchers have investigated this application (Manzano-Agugliaro et al., 2012;Sánchez-Muros et al., 2014;Tschirner and Simon, 2015;Surendra et al., 2016;Hussein et al., 2017;Su et al., 2019;Wynants et al., 2019). BSF larvae can also produce biodiesel through fat processing and biologically active substances (Li et al., 2011;Manzano-Agugliaro et al., 2012;Surendra et al., 2016;Su et al., 2019). With the help of enzymes contained in BSF larvae, contaminants in waste and nitrogen levels can be reduced by 50-60% and around 40-62%, respectively (Paz et al., 2015). ...
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Known as a promising protein source, black soldier fly (BSF) larva has attracted the attention of many researchers. BSF larvae have the ability to convert organic waste into protein. However, the growth modeling of this process has not been studied previously. Hence, this study generated a BSF larvae growth model to explain BSF larvae production. Vegetable and fruit waste collected from the Gamping fruit market was used as the growth media. The weight of larvae and the leftover substrate were measured for 20 days. The substrate consumed was related to larvae body mass. The model was properly fitted with R-squared values of 0.9988 and 0.9312 for the substrate consumption and larvae growth, respectively. The value of the kinetics constants in this study were 0.847 ± 0.018 g 0.5 day-1 for k1; 0.058 ± 0.019 g-0.5 day-1 for k2; and 0.007 ± 0.013 g-1.0 day-1 for k3­.
... Moreover, fat yields from insects have been widely studied and the reported values vary across different species from 1.5% to 77%. Even within the same insect species, a variation of fat yields is still likely to be observed due to the dissimilar types of feed ingested by the insects [5]. Out of all the species, Hermetia illucens, also known as black soldier fly, shows most promising potential for biodiesel production. ...
... Out of all the species, Hermetia illucens, also known as black soldier fly, shows most promising potential for biodiesel production. The larval feeding stage of this species only takes up to 3 to 4 weeks and its self-harvesting nature, pupating away from the medium, has eased the harvesting process [5]. Black soldier fly larvae (BSFL) are indeed native to America and the larvae stages propagate from the first to the sixth instars, then the larvae pupate before emerging into adult flies [6]. ...
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The aim of this study was to spur the lipid accumulation by larvae of Hermetia illucens or black soldier fly (BSFL) via feeding with yeast fermented medium. The Saccharomyces cerevisiae, a single cell yeast, was introduced at different concentrations (0.02, 0.1, 0.5, 1.0, 2.5 wt %) to execute an in-situ fermentation on coconut endosperm waste. The rearing of BSFL was started simultaneously and the rearing was stopped once the BSFL reached the fifth instar. With the increasing of yeast concentration, the rearing duration of BSFL was shortened from 15.5 to 13.5 days. Moreover, it was found that at 0.5 to 1.0 wt % yeast concentration, the lipid yield and lipid productivity of BSFL were statistically enhanced to their highest peaks, namely, at 49.4% and 0.53 g/day, respectively. With regard to biodiesel composition, BSFL-derived biodiesel contained mainly C12:0, C14:0, C16:0 and C18:1. The higher amount of saturated fatty acids could strengthen the oxidative stability biodiesel produced as compared with non-edible oils or microalgal lipid. At last, the addition of yeast was also found to improve the waste reduction index of coconut endosperm waste (CEW) from 0.31 to 0.40 g/day, heralding the capability of BSFL to valorize organic waste via bioconversion into its biomass to serve as a feedstock for biodiesel production.
... The fat contained C 12-18 FA and the protein-rich cakes could be used as animal feed. Thus, they are a renewable source of protein and energy (Manzano-Agugliaro et al., 2012). ...
... The use of insects for biodiesel production is promising (Manzano-Agugliaro et al., 2012). BSFL reared on foodanimal by-products for biodiesel contained 12:0 at~35% of total, and the properties of biodiesel from BSFL lipids were favorable (Li et al., 2011). ...
Article
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The effects of feeds containing several food by‐products on the fatty acid compositions of Hermetia illucens larvae were studied. Coconut, tomato, apple, and viscera by‐products, as well as combinations of control feed containing carbohydrate‐rich additives were assayed. Final live weight (mg) and daily growth coefficient (%/day) ranged from 41 and 0.548 (tomato) to 93 and 1.292 (coconut), respectively. Oils containing lauric acid were obtained from larvae‐fed vegetable by‐products, especially those fed feed containing apple, coconut, and tomato (65.3, 54.4 and 52.3% of total fatty acids, respectively). Feed containing apple and a 1:1 (w/w) mix of control feed and apple by‐products yielded the highest proportion of fatty acids in the larvae (23.5 and 15.6 g fatty acids/100 g fresh larvae, respectively). The properties of biodiesel that could be produced from larvae fatty acids were calculated and the following values were obtained: cetane number (58.5–60.2), higher heating value (38.3–39.0 MJ·kg−1), density (0.869–0.873 g·cm−3), and induction period, an index of oxidation stability (8.4–150 hours). Such values were within the ranges specified by the ASTM D6751 and Europe EN 14214:2008 standards, while values for cold filter plugging point (−9.6 to 2.8 °C) were adequate for biodiesels intended for use in temperate climates. However, values for kinematic viscosity (2.93–3.58 mm2·s−1) were slightly below the requirements of EN 14214:2008 (3.5–5.0). Overall, larvae fed food by‐products produced lauric acid‐rich oils, and the calculated properties of the oils were largely suitable for biodiesel production.
... These include fat content usually of larva, speed of completion of insect life cycle, space requirements, and feeding costs. Detailed discussions on this can be studied in the review by Manzano-Agugliaro et al. [160]. At their larva stage, metabolic reserves for non-feeding periods are developed. ...
... At their larva stage, metabolic reserves for non-feeding periods are developed. These reserves are majorly composed of high quantities of fat, in addition to glycogen and proteins [160]. Insects which have shown high lipid content include Musca domestica, Hermetia illucens, and Rhynchophorus sp. with lipid contents of approximately 21%, 29%, and 43%, respectively [161]. ...
Chapter
Biodiesel has become a very popular renewable/alternative fuel. The popularity of biodiesel is driven by the relative ease of synthesis and the wide array of feedstock from which it can be produced. These include vegetable oils, animal fats, and other sources of biomass. Vegetable oils are the main feed stock that have been used for biodiesel synthesis. To the extent that oils meant as food for humans and animals are being diverted for biodiesel production. To stop this unsustainable practice, nonedible vegetable feedstocks are constantly identified, researched, and cultivated. Much progress has been made over the last few years in this especially in terms of oils from seeds of plants such as Jatropha curcas, Calophyllum inophyllum, Azadirachta indica, Hevea brasiliensis, and Ricinus communis, among others. In addition, waste vegetable oils are also being harnessed for the purpose of biodiesel production, rather than being discarded once they degrade. Furthermore, the use of microalgae, a third‐generation source of biodiesel, was equally discussed, owing to their popularity among researchers. The increased interest is a consequence of the speed and ease of cultivation and to a larger extent the quantity of oil that could be harvested. As a matter of fact, fourth‐generation biodiesel is now being derived from genetically modified algae strains which contain even more oils. Accordingly, this chapter aims to critically review a portion of the numerous developments concerning biodiesel from non‐edible sources.
... Several authors applied different growing substrate to BSF larvae quantifying their proximate composition (Arango Gutiérrez et al., 2004;Li et al., 2011;Manzano-Agugliaro et al., 2012;Oonincx et al., 2015;Rachmawati et al., 2017;Sheppard et al., 1994;St-Hilaire et al., 2007;Veldkamp and Bosch, 2015;Zheng et al., 2012). To date, it is well accepted that the nutritional composition of BSF depends of the quality and quantity of food ingested (Gobbi et al., 2013;Nguyen et al., 2015;Pimentel et al., 2017), the fat content resulting the most variable (from 7 to 39% dry matter) ( Barragan-Fonseca et al., 2017). ...
... contains supplementary material, which is available to authorized users. (Kierończyk et al. 2019;Manzano-Agugliaro et al. 2012;Yen 2015). ...
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Within the European Union (EU), edible insects need to be approved as "Novel Food" according to Regulation (EU) 2015/2283 and must comply with the requirements of European food law with regard to microbiological and chemical food safety. Substrates used for feeding insects are susceptible to the growth of Fusarium spp. and consequently to contamination with trichothecene mycotoxins. Therefore, the current study aimed to investigate the influence of T-2 and HT-2 toxins on the larval life cycle of yellow mealworm (Tenebrio molitor (L.)) and to study the transfer of T-2, HT-2, T-2 triol and T-2 tetraol in the larvae. In a 4-week feeding study, T. molitor larvae were kept either on naturally (oat flakes moulded with Fusarium sporotrichioides) or artificially contaminated oat flakes, each at two levels (approximately 100 and 250 μg/kg total T-2 and HT-2). Weight gain and survival rates were monitored, and mycotoxins in the feeding substrates, larvae and residues were determined using LC-MS/MS. Larval development varied between the diets and was 44% higher for larvae fed artificially contaminated diets. However, the artificially contaminated diets had a 16% lower survival rate. No trichothecenes were detected in the surviving larvae after harvest, but T-2 and HT-2 were found both in the dead larvae and in the residues of naturally and artificially contaminated diets.
... It is makes FM expensive and not sustainable. Feed costs are especially high for the culture of carnivorous fish, which require great amounts of FM in their diet (Manzano-Agugliaro et al., 2012). Currently, traditional oil feed ingredients has been partially replaced with alternative sources from terrestrial plants (Fawole et al., 2016;Gatlin et al., 2007;Medale et al., 2013;Quartararo et al., 1998). ...
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The growing importance of aquaculture products for human health also raises the question of product sustainability and decreasing its costs. Insects are considered as novel feed ingredients and source of proteins. In this study, a twelve-week feeding trial with replacement of 25% fishmeal by a mixture of house cricket (Acheta domesticus) and superworm (Zophobas morio) in the fish feed was conducted with perch (Perca fluviatilis). There were no significant differences in this feeding trial, regarding survival, but decreased fish growth and increased feed conversion between the control and the experimental fed groups. Hepatic cytochrome P450 (CYP1A and CYP3A-like) activity and fatty acid (FA) composition were assessed in perch also. No significant effects were observed on cytochrome P450 activity associated with presence of toxic compounds in fish. Feeding with insect pellets resulted in significant increasing of linoleic FA and an increase of the total content of n-6 FA in fish fillets, compared to the fish fillets from control group. However, changes in FA composition were only minor and did not affect the nutritional value of the fish with insect-based diet for human consumption. Further evaluation should be conducted with different ratios or different insect species.
... Insects are part of the natural diet of freshwater and marine fish, especially in the juvenile stage. Insects often accumulate fat, especially during their immature stages (Manzano-Agugliaro et al. 2012;Gasco et al. 2018). The lipid content of non-defatted insects varies from 8.5 to 36%. ...
Article
The exponential growth of human population and their ever-increasing demands have challenged the aquaculture sector with respect to its growth, sustainability and environmental well-being. Due to the rapid intensification, aquaculture’s share of global fishmeal and fish oil consumption has more than doubled over the past decade with limited availability and high prices. Hence, the key concern of aquaculture in recent times is to reduce the environmental footprint while feeding the farmed fish with nutritionally balanced, economic and environmentally sustainable feed. But the changes in feed systems are dependent on several potential drivers, including environmental, political, economic, cultural, technological and demographic ones. The use of compound feeds formulated with a great variety of ingredients was a major step in the development of the worldwide aquaculture industry in the last century. However, the main challenges are the availability and cost of alternate feed resources, their competitiveness with other sectors, demand-supply consort with the environmental quality, social acceptability and economic growth. This review is an attempt to assess the present scenario of conventional aquafeed with an understanding of the gaining importance of alternate aquafeed along with their trade-offs addressing the principal issues of sustainability for future policy making.
... Additionally, large-scale insect breeding can occur indoors such as warehouses. Thus, there is no need to use large land areas as in the production of energy crops or to use large water areas for the production of biofuels from microalgae and crustaceans [26].The American cockroach, Periplaneta americana (L.) is one of the most familiar worldwide omnivorous insects [27]. It is a scavenger and consumes decaying organic matter. ...
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Chitin, the second most plentiful biopolymer in nature, is a major component of insect cuticle. In searching for alternative resources for fossil fuels, some fungal strains of Mucor circinelloides from an insect-source were found to produce bioethanol directly using insect chitin as a substrate. Herein, simplified methods for insect chitin extraction and application as a substrate in submerged fermentation for bioethanol production were explored. Chitin of the American cockroach (Periplaneta americana (L.)) was isolated by refluxing the cockroaches dried exoskeletons with 4% NaOH. The purity of the extracted chitin was assessed to be high when the physicochemical properties of the extracted chitin matched these of commercially available crab and shrimp samples. The extracted chitin was employed as a substrate in submerged fermentation using two strains of M. circinelloides. One of these, strains M. circinelloides 6017 showed immense potential for bioethanol production directly. It could to bio-transform 15 g/L of colloidal chitin directly to 11.22 ± 0.312 g/L of bioethanol (74% of the initial chitin mass) after 6 days of incubation. These results confirm the possibility of using insect biomass as a potential alternative resource for bioethanol production in a simple manner thus contributing to the creation of an alternate energy source.
... The properties of biodiesel obtained from BSFL lipids along with the European reference standard is summarized in (Table 2). A brief review covering various aspects of different insect species and their utilization for biodiesel production was communicated [71]. ...
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Each year, the food supply chain produces more than 1.3 billion tons of food and agricultural waste, which poses serious environmental problems. The loss of the massive quantity of secondary and primary metabolites retrievable from this resource is a significant concern. What if there is a global solution that caters to the numerous problems arising due to the humongous volume of waste biomass generated in every part of the world? Insects, the tiny creatures that thrive in decaying organic matter, which can concentrate the nutrients present in dilute quantities in a variety of by-products, are an economically viable option. The bioconversion and nutritional upcycling of waste biomass with insects yield high-value products such as protein, lipids, chitin and frass. Insect-derived proteins can replace conventional protein sources in feed formulations. Notably, the ability of the black soldier fly (BSF) or Hermetia illucens to grow on diverse substrates such as agri-food industry side streams and other organic waste proves advantageous. However, the data on industrial-scale extraction, fractionation techniques and biorefinery schemes for screening the nutritional potential of BSF are scarce. This review attempts to break down every facet of insect processing and analyze the processing methods of BSF, and the functional properties of nutrients obtained thereof.
... The energy matrix in Cuenca-Ecuador mostly depends on fossil fuels, whose extraction methods and processes transformation are an important environmental issue (Bristow and Kennedy, 2013). Forest biomass within an energy context refers to the set of renewable elements of organic origin or their derivatives, whose energy comes from solar radiation that is transformed into chemical energy during the photosynthesis process conducted by plant species (Manzano et al., 2012). This chemical energy can be used directly from combustion processes or transformed by thermal methods (gasification) or biological methods (bioethanol production), according to the final requirement of use (Yaman, 2004). ...
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Manuscrito recibido el 16 de octubre de 2019. Aceptado, tras revisión, el 11 de junio de 2020. Publicado el 1 de septiembre de 2020. Resumen Los combustibles fósiles son por ahora la principal fuente de abastecimiento energético de las ciudades. Una estrate-gia para reducir este consumo es el desarrollo de energías renovables desde recursos endógenos urbanos. Se propone una metodología para determinar el potencial energético que poseen los residuos forestales urbanos en la ciudad de Cuenca-Ecuador, obtenidos mediante las actividades de mantenimiento (poda) de las áreas verdes públicas, con el propósito de transformarlos en fuente energética. Mediante análisis en laboratorio de muestras tomadas en el medio local, se determina que el poder calorífico inferior promedio que posee la biomasa es de 0.38 tep/ton. A partir de ello, con una base de datos estadísticos se calcula que en la ciudad de Cuenca se dispone de 608.63 ton de masa forestal anualmente. Ésta cuenta con un potencial energético de 233.13 tep/año y una eficiencia para la producción de energía eléctrica de aproximadamente 41 tep/año, que permite cubrir el consumo promedio de 110 familias. Se concluye que esta fuente de energía puede crecer significativamente con el incremento de las actividades de mantenimiento de las áreas verdes públicas y además constituye una estrategia para el aprovechamiento secundario de esta clase de resi-duos. Palabras clave: Energías renovables, potencial energético, recursos endógenos, residuos forestales. 42 LA GRANJA: Revista de Ciencias de la Vida 32(2) 2020:42-53.
... If Mexico were able to convert their domestic economies and infrastructures in such a way as to exploit these energies for enhanced efficiency and service, they would be able to improve their economic situation. They would be able to spare themselves the continued environmental ravages that reliance upon fossil fuels invite (Manzano-Agugliaro, Hernández, & Zapata, 2010;Manzano-Agugliaro et al., 2012). Mexico, which has increasingly relied upon energy imports since the early 2000s (United States Energy Information Association, 2012), would seem particularly advantaged if they took a turn towards renewable energy as a means of bolstering water conveyance; to do so would signal a step towards the nation's own general energy dependence. ...
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There is a lack of research into the way that renewable energies in Mexico can be used to address water scarcity problems. The purpose is to reveal the extent to which renewable energy can resolve the challenge of water availability and service. The PRISMA method was followed. Mexico is aware of the benefits of exploiting renewable energy sources but less cognizant of use of resources to make potable water accessible.
... Amongst holometabolous insects, the percentage of fat stored can vary greatly between Orders (Manzano-Agugliaro et al., 2012), whereby on average, Coleopterans have a higher percentage of fat followed by Hymenoptera and Lepidoptera with intermediate levels and Dipterans with the lowest percentage of fat which is comparable to non-holometabolous insects (Figure 4b). Notably, the larvae of some species can have unexpected high percentages of fat as seen in the wasp Polistes instabillis (Hymenoptera: Vespidae) which has a fat percentage of >60% and a staggering 77% in the moth Phasus triangularis (Lepidoptera: Hepialidae; Ramos-Elorduy et al., 1997).This suggests that larvae are an unprecedented source of fat for biofuel production and a promising way to move forward into the renewable energy era(Gold, Tomberlin, Diener, Zurbrügg, & Mathys, 2018;Manzano-Agugliaro et al., 2012;Souza, Seabra, & Nogueira, 2018).One way to produce larval biofuel is through the recycling of organic waste and livestock manure (supporting ecosystem service; Li, Zheng, Cai, et al., 2011; Varelas, 2019), although this approach F I G U R E 6 Larvae can degrade plastic as well as be used to produce biofuel. (A) Larva of wax moths can degrade plastic. ...
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Abstract Ecosystem services are essential for the health of current and future generations and key to the sustainable development of our societies. The role of insects in providing ecosystem services has been increasingly recognized, becoming the focus of several management and conservation initiatives world‐wide. However, ecosystem services framework traditionally overlooks the full range of services that can be provided by insects, largely because services provided by life stages other than the insect adult are often neglected. In this paper, I first review the traditional ecosystem services primarily attributed to insects, namely edible insects and mass‐rearing for biological control. Next, I provide a collection of unconventional ecosystem services provided by insect larvae which highlights the importance of considering life stage‐specific services in a holistic view of the ecosystem services framework. In particular, I discuss recent advances that revealed how insect larvae can degrade plastic, which is one of humanity's greatest environmental pollutants, and how larvae can be used to produce biofuel to help overcome the increasing contribution of the fossil fuel industry to climate change. I then discuss how toxic compounds produced by the larvae of some insects provide potential new medicines for clinical treatment and lastly, I discuss a unique example of how the larval stage of insects is entrenched into the cultural values of Aboriginal communities in Australia. In conclusion, by acknowledging life stage‐specific ecosystem services provided by insects, this paper raises awareness of unconventional services that can underpin innovative solutions to contemporary global challenges, which can ultimately help create more sustainable and culturally diverse societies.
... Another important aspect that needs consideration in animal fats is in the area of lipid content in insects. Some insect species at larvae stage have shown to exceed 50% lipid content by dry weight matter (Manzano-Agugliaro et al., 2012). Insects' fat content variability is very large with a range of 2%À50% of dry matter, with some insects' polyunsaturated fatty acid content hitting 70% of the total fatty acids. ...
Chapter
Recent advancements in the technology, sustainability, and applications of biodiesel from advanced and sustainable sources have been revolutionized. New and innovative thrusts of research priorities and approach in biodiesel development especially from wastes and nonedible feedstocks have given rise to the new concept of advanced and sustainable biodiesel fuels. These sources and alternatives to the conventional crop-based sources have to be friendly to the environment and generated essentially from waste materials by way of either recycling or reprocessing of feedstock viciously as energy. Advanced biodiesel fuels have become useful in bridging the alternative energy sources gap as they are from different feedstocks with variations such as from waste plastics, waste cooking oils, from microalgae, waste residue of oil processing, glycerol after transesterification, alcohols and including biomass materials. An important research thrust is the hybridization of biodiesel feedstocks to produce new products with new properties. This chapter reviews biodiesel feedstocks, development of first-, second-, and third-generation biodiesel, the new concept of advanced and sustainable biodiesel fuels, and feedstock hybridization. Additionally, case studies, biodiesel production technologies and processes, and novel bioprocessing technologies employing metabolic engineering and biotechnology are explored. Further expose was presented in research and development needs on properties, novel approaches, production processes, and relevant outcomes, while also addressing future development and prospects in the new and gray untapped areas.
... Insect breeding space is not large compared to the large land areas required for crops such as soybeans or to the large water footprint required for microalgae production. This new alternative has become more feasible, especially for countries with limited space and highly populated areas that need to devote their land for food-source production [7]. Insect larvae can accumulate lipids as their fat body and are able to stimulate the metabolic reserves needed, especially during their immature stages such as larva, pupa and nymph. ...
Article
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The purpose of this review is to reveal the lipid and protein contents in black soldier fly larvae (BSFL) for the sustainable production of protein and energy sources. It has been observed from studies in the literature that the larval lipid and protein contents vary with the rearing conditions as well as the downstream processing employed. The homogenous, heterogenous and microbial-treated substrates via fermentation are used to rear BSFL and are compared in this review for the simultaneous production of larval protein and biodiesel. Moreover, the best moisture content and the aeration rate of larval feeding substrates are also reported in this review to enhance the growth of BSFL. As the downstream process after harvesting starts with larval inactivation, various related methods have also been reviewed in relation to its impact on the quality/quantity of larval protein and lipids. Subsequently, the other downstream processes, namely, extraction and transesterification to biodiesel, are finally epitomized from the literature to provide a comprehensive review for the production of unconventional protein and lipid sources from BSFL feedstock. Incontrovertibly, the review accentuates the great potential use of BSFL biomass as a green source of protein and lipids for energy production in the form of biodiesel. The traditional protein and energy sources, preponderantly fishmeal, are unsustainable naturally, pressingly calling for immediate substitutions to cater for the rising demands. Accordingly, this review stresses the benefits of using BSFL biomass in detailing its production from upstream all the way to downstream processes which are green and economical at the same time.
... BSF larvae have been used for decades in the pet food trade and have recently been approved as aquaculture feed in Europe, the United States, and Canada [30,31]. Moreover, researchers advocate additional industrial applications such as biofuel and pharmaceutical production [32][33][34][35]. ...
Article
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Hermetia illucens is an efficient bioconverter able to grow on various different organic materials, producing larvae, which are a good source of protein and fat with applications in the animal feed and biochemical industries. This fly’s capacity to reduce huge amounts of waste presents an interesting opportunity to establish a circular food economy. In this study, we assessed the suitability of using organic wastes from cricket and locust farming to rear H. illucens. Larvae developed until adult emergence on all the wastes, with a mean survival of over 94%. Cricket waste allowed faster development of heavier larvae than locust waste. Substrate reduction was particularly interesting on cricket waste (<72%), while locust waste was only reduced by 33%. The nutritional composition of the larvae reflected that of the growing substrates with a high protein and fat content. These results demonstrate the potential of using H. illucens to reduce and valorise waste generated when farming various insects through the production of a larval biomass for use as a protein meal in animal feeds or industrial applications.
... Lipid from insects in the form of fat is a predominant biomass composition that has been studied to produce a sustainable biofuel [11]. Larval lipid is stored in its body to be used during the non-feeding period of the larval lifecycle [9,18]. Among the various insect species such as flesh fly, superworm, mealworm beetle, housefly, latrine blowfly, soldier fly, and ants, Hermetia illucens larvae, or black soldier fly larvae (BSFL), are commonly selected for producing biodiesel since BSFL can valorize a variety of organic wastes; contain a high level of lipid content (around 50%); the adults are not a pest; they can cope with a wide range of environmental conditions, e.g., pH, temperature, and humidity; and they need less workforce for mass rearing [19][20][21][22][23][24][25][26][27][28]. ...
Article
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Black soldier fly larvae (BSFL) have been employed for valorizing organic waste materials as the larvae are able to consume organic waste and transform it into valuable larval biomass. In this study, BSFL were found to potentially reduce blended sewage sludge. The addition of palm kernel expeller (PKE) fortified the protein and lipid content in blended sewage sludge substrates, leading to larval growth enhancement. In addition, the larval weight also influenced the lipid yield and fatty acid methyl ester (FAME) profile. However, the optimum ratio of sewage sludge to PKE had to be determined as excess PKE content could become a threat to larval growth by contributing to the reduction of non-fiber carbohydrates content in the feed, thereby resulting in the decrease in lipid yield and FAME content. In this work, a sewage sludge to PKE ratio of 2:3 proffered the highest larval weight gained at 46.99 ± 2.09 mg/larva. Meanwhile, a proportion of 3:2 of sewage sludge to PKE was able provide the highest lipid yield of 17 ± 1.77%. Furthermore, the FAME profile revealed the presence of a significant amount of saturated and monosaturated fatty acids, indicating a good quality biodiesel. Thus, BSFL-based biodiesel fed with blended sewage sludge and PKE could be utilized for producing a high quality biodiesel. However, further improvement on the amount of lipid yield and FAME content should be further investigated.
... The use of WFTs as an example of insects for biodiesel production is justified by the fact that insects are capable of accumulating metabolic reserves known as fat bodies, which they can use during certain non-feeding periods of their life cycle (Kalu-Uka et al., 2021). The fat content of a large number of insect species ranges from 25 to 77%, and the excess fat could be used for biodiesel production (Manzano-Agugliaro et al., 2012). The fat body is critical to the WFTs insect metabolism (Fombong and Kinyuru, 2018). ...
Article
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Beyond energy crisis, biodiesel offers renewable and unlimited option to the challenges associated with fossil fuels depletion. Biodiesel could reduce the carbon foot print and gas emissions. Therefore, China has set an audacious goal of carbon neutrality by 2060. In order to reduce the cost of biodiesel production, it is critical to look for alternative feedstocks and unconventional resources. Biodiesel can be produced from renewable and sustainable feedstocks like edible and non-edible oils, insects, municipal sewage sludge, and oleaginous microorganisms. Existing life cycle assessments of yeast-based biodiesel production are required to assess potential environmental impacts and obtain a holistic picture. The circular economy paradigm has recently emerged as a viable alternative to linear, unsustainable production and consumption systems. Given the legislative requirements and the circular economy principle, the use of textile azo dye wastewater is a promising alternative for its management. The annual disposal of 4,500,000 tons of textile dyes is an environmental and socioeconomic concern due to their carcinogenic potential. Azo dyes account for over 70% of global industrial demand. Biological-mediated azo dye degradation is thought to be cost-effective, and environmentally friendly when compared to physical and chemical approaches. To this end, yeasts can play a significant role, owing to their high growth rate, tolerance to extreme conditions, and ability to effectively degrade lignin and aromatic compounds, concurrently representing a highly promising feedstock for biodiesel production. Interestingly, an emphasis has been recently given on novel symbiotic yeasts isolated from termite guts as promising microbiomes for multiple biotechnological applications. Therefore, this review focuses on recent findings of biodiesel production from azo dye degrading yeasts inhabiting termite guts. While capturing recent research advancements for sustainable biodiesel production, this review emphasizes a novel concept for using azo dyes/aromatic wastes as a feedstock for biodiesel production.
... Another important aspect that needs consideration in animal fats is in the area of lipid content in insects. Some insect species at larvae stage have shown to exceed 50% lipid content by dry weight matter (Manzano-Agugliaro et al., 2012). Insects' fat content variability is very large with a range of 2%À50% of dry matter, with some insects' polyunsaturated fatty acid content hitting 70% of the total fatty acids. ...
Chapter
Global energy demand is expected to increase by 48% in the next 20 years owing to the precipitous increase in the global population. Currently, 80% of the energy demand is met by fossil fuels. However, rapidly depleting fossil fuel reserves coupled with the negative environmental impacts from its combustion has prompted significant interest in sustainable biofuels. This will aid in the transition toward a carbon-neutral bio-economy. Several feedstocks have been identified as possible substrates for biofuel production. Agricultural residues have shown significant potential since they are environmentally benign, abundant, and low cost. Nevertheless due to its structural complexity, an appropriate pretreatment is required to enhance enzymatic and microbial conversion. Currently, first-generation biofuels such as bioethanol do not require intensive pretreatments; however, the major drawback is the utilization of food crops, thus contributing to the food versus fuel debate. Additionally, greenhouse gas emissions associated with first-generation biofuels are another obstacle. Second-generation biofuels such as bioethanol, biohydrogen, and biomethane appear to be most promising owing to its bioconversion from waste material. A major bottleneck in this process is the requirement of costly pretreatments and subsequent effluent treatment. Third-generation biofuels such as bioethanol from microalgae also show potential since process optimization could significantly enhance yields. Fourth-generation biofuels aim to utilize genetically optimized feedstocks that are designed to enhance capture of carbon dioxide; however, carbon capture and sequestration technology has limited the commercialization of this process. Integrated biorefineries have the potential to produce several generations of biofuels in one process, thereby completing valorizing the feedstock and enhancing the life cycle and techno-economic assessment of the bioprocess.
... The larvae can be processed as feeds for cows, swine, and various poultry species and also for aquaculture species (Newton et al., 2005a;Barroso et al., 2014;Ur Rehman et al 2017;Wang and Shelomi, 2017). Some crude fats of BSF larvae can be changed to biofuels (Manzano-Agugliaro et al., 2012;Zheng et al., 2012;Leong et al., 2016), and one thousand larvae can produce 36g to 91g of biofuel, depending on the type of material in which they are raised (Li et al., 2011a;Li et al., 2011b). Currently black soldier fly larvae oils are been tested for use as skin care products in the multibillion beauty industry (Sangduan, 2018). ...
Thesis
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Fish feed protein ingredients are the most expensive and often unavailable in subSaharan Africa especially in commercial aquaculture systems. The major fish feed protein ingredient in fish farming in Kenya is fishmeal (FM) that is often times expensive and adulterated leading to low productivity of fish farming. This problem has necessitated a need for exploring alternative less expensive and easily available protein sources such as black soldier fly larvae (BSFL). This study aimed at evaluating the growth rate, feed utilization, survivability and carcass characteristics of the African catfish (Clarias gariepinus) reared on diets containing BSFL meal as a replacement for FM. Treatment diets were formulated for BSFL meal to replace FM at the rate of 0% (C), 25% (D1), 50% (D2), 75% (D3), 100% (D4) and D5 (49% BSFLM, 49% FM and 2% Baker’s yeast). All diets were formulated to meet the nutritional requirements of catfish. The catfish were housed in harper nets each measuring 2 by 2 by 2 meters and the net had one millimeter perforations to allow proper circulation of water and also prevent escape of the catfish. Each harper net held 20 pieces of catfish. The experiment was laid out in a completely randomized design with each treatment being replicated three times. The performance of the catfish was determined by recording the weights, lengths and mortality biweekly for six months. Analysis of variance was carried to determine the effects of the treatment diets on the weight gain, length gain and carcasses charateristics. Water quality parameters including dissolved oxygen, temperature, salinity and conductivity measured were within the optimum levels recommended for rearing the African catfish. Catfish consuming diets with 50% and 75% BSF larvae meal had the highest growth rates of 1.01g/day and 0.98g/day respectively. However, the growth rates of the catfish consuming the diets with 0% and 100 % BSFL meal as well as the diet containing 2 % baker’s yeast were not significantly different (P>0.05). Mortality of 1.10% was noted in the catfish consuming the control diet and diet containing 25 % BSFL but there was no mortality for the other treatment groups. Carcasses of African catfish fed treatment diets with BSFL meal had significantly (P<0.05) higher amounts of crude protein (CP) especially for D2 and D3. Ether extracts from the carcasses showed that an increase in BSFL meal led to an increase in the lipid content of the carcasses. The inclusion of BSFL meal did not negatively affect the nutritive composition and carcass quality (especially essential amino acids) of the African catfish. The study noted that the concentration of essential amino acids increased as the amount of BSFL meal in the diets increased. Substitution of BSFL meal for FM in the treatment diets didn’t negatively affect the survival rates of the catfish. The study recommends the use of BSFL meal at substitution rates of 50% and 75% for better survival and enhanced growth performance of African catfish as well enhanced quality of its carcass.
... It is evident that fossil fuels are globally still a critical energy source. However, there are limited reserves of fossil fuels, and their overuse is accompanied by environmental degradation [5][6][7]. Thus, this situation encourages the use of renewable resources even more than before. ...
Article
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Biomass pyrolysis is considered as a thermochemical conversion system that is performed under oxygen-depleted conditions. A large body of literature exists in which thermodynamic equilibrium (TE) and kinetic approaches have been applied to predict pyrolysis products. However, the reliability, accuracy and predictive power of both modeling approaches is an area of concern. To address these concerns, in this paper, two new simulation models based on the TE and kinetic approaches are developed using Aspen Plus, to analyze the performance of each approach. Subsequently, the results of two models are compared with modeling and experimental results available in the literature. The comparison shows that, on the one hand, the performance of the TE approach is not satisfactory and cannot be used as an effective way for pyrolysis modeling. On the other hand, the results generated by the new model based on the kinetic approach suggests that this approach is suitable for modeling biomass pyrolysis processes. Calculation of the root mean square error (RMS), to quantify the deviation of the model results from the experiment results, confirms that this kinetic model presents superior agreement with experimental data in comparison with other kinetic models in the literature. The acquired RMS for the developed kinetic method in this paper varies within the span of 1.2 to 3.2 depending on temperature (400–600 °C) and various feedstocks (pine spruce sawdust, bagasse, wood bark, beech wood and paddy straw).
... In order to obtain protein-rich BSFL meal, a substantial amount of fat is removed by technological processing of the BSFL. The resulting fat is currently mostly considered for non-food purposes, like biodiesel production (Manzano-Agugliaro et al., 2012;Leong et al., 2016). However, as this form of use represents a great loss of potentially valuable feed energy, it is important to determine how its use affects the composition of the final animal product. ...
Article
Implementing insects, such as the black soldier fly larvae (BSFL), as animal feed commonly includes the previous removal of substantial amounts of fat. This fat may represent an as yet underutilized energy source for livestock. However, transfer of lauric and myristic acid, prevalent in BSFL fat and undesired in human nutrition, into animal-source foods like eggs may limit its implementation. To quantify this, a laying hen experiment was performed comprising five different diets (10 hens/diet). These were a control diet with soybean oil and meal and a second diet with soybean oil but with partially defatted BSFL meal as protein source. The other three diets were based on different combinations of partially defatted BSFL meal and fat obtained by two different production methods. Lauric acid made up half of the BSFL fat from both origins. Both BSFL fats also contained substantial amounts of myristic and palmitic acid. However, in the insect-based diets, the net transfer from diet to egg yolk was less than 1% for lauric acid, whereas the net transfer for myristic and palmitic acid was about 30% and 100%, respectively. The net transfer did not vary between BSFL originating from production on different larval feeding substrates. The results illustrate that hens are able to metabolize or elongate very large proportions of ingested lauric acid and myristic acid, which are predominant in the BSFL lipids (together accounting for as much as 37 mol%), such that they collectively account for less than 3.5 mol% of egg yolk fatty acids.
... They have a high-fat content of 34 to 40%, which is similar to edible oils such as canola oil (40%), jatropha oil (30 to 40%), and palm oil (50%) [8]. Insect breeding will not exploit the use of agricultural land for crop plantation [9]. On the contrary, it can help to overcome food insecurities caused by standard farming practices. ...
Article
The physical and chemical properties of mealworm (Tenebrio molitor) oil were studied. Mealworm powder has a high oil content of 37.54 ± 0.78% with a high free fatty acid (FFA) content of 10.84 ± 0.005%. The primary fatty acids of mealworm oil were oleic acid (30.37%), linoleic acid (25.07%) and palmitic acid (19.54%). The mealworm oil decomposed almost completely after 470 °C. An optimization study of acid-catalyzed esterification using response surface methodology (RSM) was conducted to reduce the high level of FFA content to a range below 1% to be suitably used for biodiesel production via alkali-catalyzed transesterification. The optimum parameters were 5.8% w/w sulfuric acid as catalyst, 24:1 methanol to oil ratio, 174 min reaction time at a temperature of 74 °C. The methyl esters conversion obtained using these optimum condition parameters was 92.74 ± 0.92% indicating FFA content was successfully lowered to less than 1%, which is favorable for alkali-catalyzed transesterification to take place and convert the triglycerides in the oil into biodiesel. The pretreated oil is then converted to biodiesel and the properties were found to meet the ASTM D6751 standards.
... TOrCs (e.g., bifenthrin) that primarily accumulate in lipid or fatty fractions of BSFL tissues may be eliminated from protein-based BSFL feeds by using defatting processes. The separated fatty fractions could be used in nonconsumptive pipelines such as biofuel production (Wang and Shelomi, 2017;Su et al., 2019;Manzano-agugliaro et al., 2012), while improving the quality of the protein-rich end-products derived from BSFL tissues. ...
Article
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Most bioaccumulation assessments select one or several compound classes a priori for analysis performed by either liquid or gas chromatography coupled with mass spectrometry (LC-MS or GC–MS). When organisms are exposed to complex mixtures of trace organic contaminants (TOrCs), targeted chemical assays limit understanding of contaminant profiles in biological tissues and associated risks. We used a semi-quantitative suspect-screening approach to assess the bioaccumulation potential of diverse TOrCs in black soldier fly larvae (BSFL) using almond hulls (by-products of the booming almond industry in California) as test substrates. BSFL digestion is gaining traction as a resource recovery strategy to generate animal feed from low-value organic wastes. We screened almond hulls from six California farms for the presence of 5728 TOrCs using high resolution mass spectrometry. We then categorized the risk potential of 46 TOrCs detected in the hulls based on their predicted bioaccumulation, persistence, and toxicity in order to select two hulls for an in situ BSFL bioaccumulation screening study. We analyzed larvae tissues and feeding substrate initially and after 14 days of growth using targeted, suspect-screening, and nontarget-screening methods. The survival rate of BSFL in all rearing reactors was greater than 90%, indicating low toxicity of the substrates to BSFL. Esfenvalerate, cyhalothrin, and bifenthrin were the most abundant pyrethroids quantified (81.7 to 381.6 ng/g-dw) in the hulls. Bifenthrin bioaccumulated in BSFL tissues (14-day bioaccumulation factor, BAF, of 2.17 ± 0.24). For nontarget analysis, kendrick mass defect (KMD) analysis of PFAS homologous series revealed hydrogen-substituted perfluoroalkyl carboxylic acids (H-PFCAs) in the hulls and BSFL tissues after growth. Our approach demonstrates the utility of suspect-screening in chemical safety assessments when organic wastes with highly diverse and variable contaminant profiles are used in resource recovery pipelines.
... In Another work, they extracted FFA content of 90% from chicken fat oil at 18:1 MeOH to oil ratio, 5 wt % catalyst loading, 70 • C reaction temperature, and 1 h reaction time . In recent decades insects were found to be a reliable source for biodiesel having higher FFA content of above 77% (Manzano-Agugliaro et al., 2012a). (Li et al., 2012) extracted biodiesel from C. megacephala (Fabricius) larvae insect by transesterification process. ...
Article
The entire world is witnessing climate change and its impact on the environment caused by humans. Pollution and the reliance on ever depleting fossil fuels are the major sources. This is a pressing concern to discover a sustainable substitute for energy. In this present research work, the Silkworm Oil Methyl Ester (SWOME) has been prepared by a two-step transesterification process. The catalyst used is Sulfuric acid (H2SO4) for esterification and Sodium hydroxide (NaOH) for the second step process. The biodiesel yield is 98.9 wt% is obtained for SWOME at the catalyst concentration of 1.5%, constant temperature of 65°C, methanol to oil molar ratio of 12:1, 400 rpm, and 60 min of reaction time. The physicochemical properties of methyl ester silkworm oil have been tested and are found with ASTM standards. To further enhance the property of SWOME, Nano additive Aluminium Oxide (Al2O3) is added. The various blends of SWOME have been prepared and tested with the single-cylinder stationery (DI) diesel engine to investigate its Performance and Combustion. Brake thermal efficiency is found to be 33.1% for B30SWOME with 75ppm nano additive, which was 3.7% higher than that of diesel. The fuel is also tested against the effectiveness of Diesel Oxidation Catalyst (DOC) as a Post-combustion technique to reduce HC and CO emission. From the experimental testing, it is observed that HC for B30SWOME is 90% reduced and CO emission is found to be reduced up to 85% after retrofitting the DOC system. From the result, it is observed that SWOME Nano additive with DOC has more advantages on engine behavior.
... Insects have the ability to convert organic waste into proteins and fat at a high conversion rate . The protein and part of the fat can be utilised directly in the feed industry and the rest of the fat has further uses in the biofuel and other processing industries (Fowles and Nansen, 2020;Li et al., 2011;Manzano-Agugliaro et al., 2012;Wang et al., 2017;Zheng et al., 2012). However, in most countries, there is a regulation in place, which prevents large-scale production of insects for food and feed use (Lähteenmäki-Uutela and Grmelová, 2016;Lotta, 2019;Pinotti et al., 2019). ...
Article
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Numerous studies show that insects are efficient in converting organic waste into proteins and fats, which makes them an interesting alternative source of feed. Moreover, since around one-third of global food produced for human consumption is lost or wasted, the production of insect-based meals from food waste is considered a sustainable alternative to other protein sources. This paper introduces a quantitative framework able to analyse the economic implications of developing a large-scale insect-based meal industry worldwide, which would require important regulatory changes. Our calculations, based on findings from the literature, suggest that almost 1.4 billion tonnes of food, that could potentially be used as insect feed, went to waste at the world level in 2018, a figure that is projected to rise to 2 billion tonnes by 2030. Results show that the use of food waste for insect meal and oil production would have important downward price impacts on meals and oils (fish- and plant-based), reducing feed costs and stimulating global aquaculture and livestock production, reducing total land use for agriculture production and lead to a lower dependence on protein imports.
... In the available literature, various fat-extraction methods from selected insect species have been deliberated, such as solvent systems (direct methylation, pure n-hexane, pure acetone, ethanol with water, hexane with ethanol, and direct saponification), Soxhlet, Fohl, S-C CO 2 extraction and mechanical pressing (Jin et al., 2012;Kroeckel et al., 2012;Purschke et al., 2017b;Ramos-Bueno et al., 2016). The processing of insect biomass plays a crucial role due to the difficulty of lipid droplet acquisition due to their distribution in the invertebrate body; thus, extraction efficiency varies depending on the techniques used (Manzano-Agugliaro et al., 2012;Purschke et al., 2017b;Sun et al., 2018). To increase the effectiveness of the extraction process, microwave irradiation and sonication methods have been used (Sun et al., 2018;Wang et al., 2017). ...
Article
This study aimed to evaluate the partial or total replacement of soybean oil with cold-extracted Hermetia illucens larvae (BSFL) fat in young turkey diets on growth performance, coefficients of apparent ileal nutrient digestibility, pancreatic enzyme activities, selected gastrointestinal tract (GIT) segment measurements, microbial community modulation, selected biochemical blood indices, hormone concentrations, immune status traits, and muscle and liver tissue traits. A total of 216 7-day-old female turkeys (B.U.T. 6) were randomly allotted to 3 dietary treatments. Each group contained 6 replicate pens with 12 birds per pen. The birds were fed a soybean-maize basal diet enriched with 50 g/kg dietary fat, i.e., soybean oil (SO) in the control group, 50:50 SO and H. illucens larvae fat in the BSFL50 treatment group, and BSFL fat as the sole energy source in the BSFL100 group. The experiment lasted 28 days. The provided BSFL fat was characterized by high lauric and palmitic acid contents, as well as saturated fatty acids (SFAs), while concentrations of mono- and polyunsaturated fatty acids were higher in the SO group. The growth performance parameters were not affected (P>0.05) by BSFL fat substitution. However, the apparent ileal digestibility of the ether extract was significantly increased (P<0.001) after BSFL fat inclusion as the sole energy source with simultaneous enhancement (P<0.001) of lipase activity. Partial or total replacement of SO with BSFL fat improved cecal microbiota communities by limiting (P<0.001) Bacteroides-Prevotella cluster counts. Additionally, the beneficial effect of BSFL100 was observed in the case of a decreased (P=0.004) IL-6 concentration. In conclusion, it is possible to partially or totally substitute SO in turkey diets with cold-extracted BSFL fat without any negative effect on growth performance, nutrient digestibility, physiological traits, or immunological status traits. Furthermore, the cold-pressing technique can be adopted and recommended to obtain BSFL fat as a dietary energy source in turkey nutrition.
... Lipid content averages about 20% (DM basis), and therefore tends to be higher than fishmeal (usually around 8%) or soy meal (around 3%). This has some advantages: it could be useful when formulating high energy diets for animal livestock, like broiler chickens (Sánchez-Muros et al., 2016), or -if properly extracted could serve other purposes: some authors have even proposed use of insect oil to produce biodiesels, and the resulting enriched-protein paste could be used for animal feed (Manzano-Agugliaro et al., 2012). ...
Thesis
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The aquafeed industry is highly dependent on fishmeal (FM) and high-protein plant substitutes. Rising costs and sustainability concerns are fueling the search for novel alternatives. Black Soldier Fly (BSF) larvae (Hermetia illucens) have been demonstrated to be a potential new source of sustainable protein. While they can be grown on a wide range of waste-substrates, have a short life-cycle, and a favourable nutritional profile, they can be seen as a credible candidate. In this thesis, we focused on the selection of a potential substrate in a local context, and the type of larval stage to harvest in order to optimise both production and quality of the maggot meal (MM). From these preliminary studies fruit waste were selected to grow the larvae, harvested at the “white larvae” stage to produce the MM. As the availability of MM is yet –far- from being sufficient to cover the ever-growing demand for aquafeed, a strategic use was decided in contextualised and commercially-relevant researches. In large-scale tilapia farm, all-male production is desired to optimise the production as they grow bigger and faster than females. To do so 17α-methyltestosterone is added to the feed during the first 21 days of the fry. To maximize the ingestion, low quantities but high quality feed are required. In this context, the MM was used as a feed-hormone carrier for tilapia fry (Oreochromis niloticus) in two experiments. Whereby the first was based on simple substitution of fish meal (FM) and commercial feed with MM (Chapter 5), the second compared 12 isoenergetic and isoproteic formulated feeds based on a prior MM digestibility analysis (Chapter 6). Results indicated that different dietary inclusions of MM did not significantly affect sex reversal rates nor fish production performance, suggesting that MM offers potential as a locally sourced feed ingredient for tilapia hatchery. This strategic application is further enhanced by the potential to co-located MM and fry-production offering producers’ greater ability to manage quality assurance.
... The fat from some insects was proven to be a sustainable feedstock for biodiesel production [100][101][102][103]. In particular, insects can accumulate saturated fatty acids (i.e., C18 and C16) with physical and chemical properties, such as kinematic viscosity, calorific value, oxidation stability, conducive to further conversion into biodiesel [104]. Although there are different kinds of insects, few species have been studied to convert organic wastes into biodiesel [105]. ...
Article
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Over the last few years, the concept of Circular Economy (CE) has received a lot of attention due to its potential contribution to the Sustainable Development Goals (SDGs), especially by reconciling economic growth with the protection of the environment through its grow-make-use-restore approach. The use of insects in circular production systems has been a good example of this concept as insects can transform a wide range of organic waste and by-products into nutritious feedstuffs, which then go back into the production cycle. This paper explores the potential of mealworms (Tenebrio molitor) in circular production systems by reviewing their use and applicability in several industries such as pharmaceuticals, agriculture, food, etc. Despite the high versatility of this insect and its potential as a substitute source of nutrients and other valuable components, there are still many legislative and behavioural challenges that hinder its adoption and acceptance.
Article
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Hermetia illucens (Black Soldier Fly) larvae (BSFL) have great potential as new protein source for either feed or food use due to the high content of protein and fat. BSFL may be used in different forms including dried with extended shelf life. Mathematical models describing dehydration kinetics are useful to optimize BSFL drying conditions. A non-stationary 3D diffusion model, given by Fick's Law was used to describe the moisture depletion inside BSFL during drying. The numerical solution of PDE was obtained with COMSOL Multiphysics assuming simple boundary conditions. Data were obtained in a drying experiment performed with fresh larvae uniformly laid on a metallic grid in a forced air oven at 80 °C. Five randomly larvae were periodically selected and removed for moisture content determination until equilibrium moisture was reached. A qualitative good agreement between predictions and data was observed corroborating that the main physical phenomena were considered in the mathematical description. A better quantitave description is expected with the improvement of the boundary condition at larvae surface in the model and the upgrading of the three-dimensional geometry used as domain for the numerical resolution.
Article
Background: α-linolenic acid is an essential unsaturated fatty acid in organisms. However, there is a large gap between α-linolenic acid accumulation and its synthesis mechanism in insects. Fatty acid synthases (FASs) and desaturases (Desats) are vital enzymes required for the synthesis of unsaturated fatty acid. Results: The pupae of Glyphodes pyloalis (Lepidoptera: Pyralidae), which is a destructive pest of mulberry trees, contain the highest level of α-linolenic acid compared to other life history stages. To further explore the synthesis mechanism of α-linolenic acid in G. pyloalis pupae, we constructed a pupal transcriptome dataset and identified 106 genes related to fatty acids metabolism from it. Among these, two fatty acid synthases (GpylFAS) and five desaturases (GpylDesat) were identified. A qRT-PCR validation revealed that GpylFAS1 and GpylDesat1, 2, 3, 5 were expressed highest at pupal stages. Furthermore, the content of α-linolenic acid decreased significantly after silencing GpylFAS1 and GpylDesat5, respectively. Besides, knocking down GpylFAS1 or GpylDesat5 resulted in more malformed pupae and adults, as well as lower emergence rates. Meanwhile, silencing GpylFAS1 or GpylDesat5 affected the expressions of the other GpylFASs and GpylDesats. Conclusion: The present results illustrate the pivotal function of FASs and Desats in α-linolenic acid biosynthesis and metamorphosis in insects. Our research also broadens the sources of unsaturated fatty acids, especially for α-linolenic acid from insects, and provides novel insights for the management of mulberry insect pests from the perspective of utilization rather than control. This article is protected by copyright. All rights reserved.
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Scarce water resources, degrading land resources, and declining natural fish stocks as a result of a growing population create an urgent and critical need for more sustainable sources of protein, than ever before. In a bid to meet this need, a novel nutrient recycling process in which black soldier flies (BSF) are fed on organic wastes to produce a natural, cost-effective, and a protein source alternative to fishmeal has been established, with a biomass lipid by-product called maggot oil. The mass of the maggot oil by-product derived from this industrial process in South Africa is estimated at an annual 1300 tonnes. The sustainability of the oil production is guaranteed based on the current astronomical demand of this protein meal. This study highlights the potential benefits of using MagOil as feedstock for biodiesel production. MagOil is a potential renewable feedstock that is sustainably available with no competition for resources with food/feed production. Results of the maggot oil characterization, fatty acid composition, acid value, saponification, density, and viscosity as well as the fatty acid profile analyzed using GC-FID are presented. The acid and saponification values of the maggot oil were 3.6 and 176.43 mg KOH/g respectively. The oil had a density of 0.883 g/ml and average kinematic viscosity of 43.16 mm2/s at 40 °C. Transesterification of maggot oil with methanol using conventional potassium hydroxide and sodium hydroxide biodiesel homogeneous catalysts resulted in 75% and 65% biodiesel yield, respectively. This further, using a synthetized heterogeneous catalyst in a single and two-step transesterification, yielded biodiesel of 41% and 60%, respectively. The samples of biodiesel produced were characterized qualitatively and complied with the international biodiesel standards.
Article
Biodiesel or biodiesel–diesel fuel is the current fuel used to power transportation engines. Contamination on lubricating oil is a common issue due to leakage or extensive use of engines. This study explores the lubricant oil blend’s friction and wear with the biodiesel derived from waste cooking oil, waste cooking oil blend withCalophyllum inophyllum oil, and biodiesel–diesel blend. The blending of biodiesels and biodiesel–diesel blend with lubricant oil varies from 5% to 25% of biodiesels and biodiesel–diesel with 95% to 75% of lubricating oil based on volume ratio. The test was conducted using a four-ball tribotester according to the ASTM D 4172. The result showed that blending of BWCIL75 with biodiesel–diesel has the lowest friction coefficient (0.072) among tested oil. The wear scar on the ball bearing lubricated with the blending mixture showed an acceptable diameter value. The wear morphology has shown that a worn surface with black spots provides more protection to the tested ball. The result found that fatty acid contained in the biodiesel and the low viscosity of biodiesel significantly reduced the frictional coefficient of the lubricating oil and worked as wear prevention. Mechanical efficiency of machinery component favour low coefficient of friction. This study indicated that biodiesel produced from waste cooking oil blended with Calophyllum inophyllum oil shows better lubricity and can be used as an additive to petroleum-based lubricant for better automotive engine performance.
Article
Fresh water samples from six perennial rain fed reservoirs were collected for isolation of microalgae by enrichment method. Eighteen isolates belonging to cyanophyta and chlorophyta were obtained after 15 days of incubation in BG-11 medium under 16: 8 light and dark cycle at room temperature. Upon evaluation of oleaginous potential for future application in biodiesel synthesis, only three isolates BV3 (Nostoc sp.), BV4 (Nostoc sp.) and BV14 (Cyanobacteria) were selected. Lipid production, growth profile and lipid characteristic were also studied for the three isolates. The lipid content of the isolates BV 3, BV4 and BV14 were found to be 12.306 ± 1.313, 17.309 ± 2.129 and 26.567 ± 3.582% DW, respectively and lipid productivity recorded were 0.159 ± 0.011, 0.106 ± 0.007 and 0.046 ± 0.004 g L⁻¹d⁻¹, respectively. The specific growth rate was also determined for BV3 (0.177 d⁻¹), BV4 (0.233 d⁻¹) and BV14 (0.183 d⁻¹). Analysis of lipid further revealed the presence of neutral lipids and saturated short chain alkanes.
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HIL are useful in agriculture because they can be used as feed for livestock or fertilizer and can bioconvert organic wastes, such as food waste and human and animal manure to usable fertilizer. In addition, HIL are being studied as a source of biodiesel because of their high-fat content. However, their use for biodiesel production has not been fully adopted. Here, the results showed that survival, weight gains, and total dried weight were significantly enhanced when HIL were fed dried-food waste (DFW)/chicken manure (CM). Furthermore, increased weight gain was observed in HIL fed DFW containing 5 mL waste cooking oil (WCO) per 100 g and 1.2% (v/w) fermented effective microorganism (F-EM). Based on these results, we prepared experimental feeds containing DFW, CM, WCO, and F-EM to establish an optimal feed for biodiesel production. We found that FT-1-2, a feed prepared with 60 g DFW, 40 g CM, 2 mL WCO, and 0.8% F-EM (v/w), significantly enhanced fat content, weight gain, and total dried weight of HIL. Our results indicate FT-1-2 is a suitable feed to breed HIL for biodiesel production. We then developed an automatic oil extractor for biodiesel production. The yield of the oil extractor was higher than that of solvent extraction. The study shows FT-1-2 is an optimal HIL feed for biodiesel production and that the developed oil extractor is useful for the extraction of crude oil from HIL and for the harvesting of defatted HIL frass for livestock feed and fertilizer. Taken together, we established an optimized low-cost feed for HIL breeding and developed an automatic oil extractor for the production of biodiesel from HIL.
Chapter
Feedstock is an important aspect and source of any production process. Biodiesel feedstocks are not exceptional as they are the main source and determinant factor of type and quality of biodiesel. Biodiesel feedstocks come in different forms such as edible and non-edible agricultural plant origin. Other feedstocks sources currently in existence or development are from biomass and waste resources in nature. For example, bagasse, food waste, agricultural waste and municipal solid waste streams sources. Biodiesel feedstocks offer hope as they contain lower emission pollutants compared to petroleum fossil-based fuels. Biodiesel feedstocks thus contain inherent merits, which enhance and promote combustion reactions. In the last two decades, biodiesel researchers and developers have continued to come up with more merits, which have been tipping towards wide commercialization of biodiesel feedstocks production. This chapter offers a glimpse into the different classification of feedstocks. However, the main classification remains first, second and third generation of biofuels besides the smart fuels now coming in the Fourth Industrial Revolution.
Article
Due to the popularization of insect consumption, several studies have been carried out to elucidate the most diverse questions about nutritional factors, risks related to consumption, processing, production, potential applications, among others. Since then, the high content of insect protein is what has been the most highlighted topic researched. However, insect lipids have gained attention in recent studies. Lipids from insects have excellent nutritional value and can be as healthy as lipids presented in traditional foods. Depending on the insect stage of life, the lipid content and composition may change. In addition to proteins, lipids have been gaining ground in the field of research representing a promising ingredient for the manufacture of insect-based ingredients. In this review, aspects of the nutritional value related to insect lipids, the main processes of extraction, their composition and their current and future possible applications were reported.
Article
The increase of annual organic wastes generated worldwide has become a major problem for many countries since the mismanagement could bring about negative effects on the environment besides, being costly for an innocuous disposal. Recently, insect larvae have been investigated to valorize organic wastes. This entomoremediation approach is rising from the ability of the insect larvae to convert organic wastes into its biomass via assimilation process as catapulted by the natural demand to complete its lifecycle. Among the insect species, black soldier fly or Hermetia illucens is widely researched since the larvae can grow in various environments while being saprophagous in nature. Even though black soldier fly larvae (BSFL) can ingest various decay materials, some organic wastes such as sewage sludge or lignocellulosic wastes such as waste coconut endosperm are destitute of decent nutrients that could retard the BSFL growth. Hence, blending with nutrient-rich low-cost substrates such as palm kernel expeller, soybean curd residue, etc. is employed to fortify the nutritional contents of larval feeding substrates prior to administering to the BSFL. Alternatively, microbial fermentation can be adopted to breakdown the lignocellulosic wastes, exuding essential nutrients for growing BSFL. Upon reaching maturity, the BSFL can be harvested to serve as the protein and lipid feedstock. The larval protein can be made into insect meal for farmed animals, whilst the lipid source could be extracted and transesterified into larval biodiesel to cushion the global energy demands. Henceforth, this review presents the influence of various organic wastes introduced to feed BSFL, targeting to reduce wastes and producing biochemicals from mature larvae through entomoremediation. Modification of recalcitrant organic wastes via fermentation processes is also unveiled to ameliorate the BSFL growth. Lastly, the sustainable applications of harvested BSFL biomass are as well covered together with the immediate shortcomings that entail further researches.
Article
Insect meals are a group of promising feed materials and sources of nutrients. Their production does not entail deforestation, global warming, environmental pollution or decreased biodiversity. One of the most important farmed insect species is mealworm, which is allowed to be used in aquafeeds by the European Commission Regulation no. 2017/893. The aim of this study was to examine four doses of mealworm meal (TM10 = 10%, TM20 = 20%, TM30 = 30% and TM40 = 40%) in sea trout (Salmo trutta m. trutta) fingerling diets and their effects on growth performance, somatic and condition indices, blood parameters, histomorphological characteristics and body composition. Our results showed the most satisfactory growth performance results with 10% mealworm meal. The feed conversion ratio (FCR), protein efficiency ratio (PER), relative growth rate (RGR) and specific growth rate (SGR) was similar in the control and TM10 group. The lowest fish survival (95%) was occurred in the group of fish fed TM40, and the highest (98.33%) in fish fed control or TM10 diets. The fish condition and the hepatosomatic index were similar among treatments. The histomorphological structures of the intestine and liver were not negatively affected by the experimental diets. The inclusion of up to 40% mealworm meal did not negatively affect growth performance, feed utilization, fish health or survival.
Article
Oslo agreement was signed in 1993 between the Palestinians and the Israelis as a gesture of hope for the autonomy of the Palestinians on their lands. Palestinians lands was divided into three administrative regions: Areas A, B, and C. These divisions were signed as a temporary transitional period of 5 years, during which the transfer of control over areas C and B to the Palestinian National Authority, was not implemented until the time of writing this research. This work aims to shed light on the impact of the geopolitical division on the possibility of exploiting renewable energy resources on C areas, and the role of that in achieving the Palestinian vision of reducing total dependency on the Israeli side as a net importer of Energy. To conclude, 96% of the total potential of solar energy is in West Bank, while Gaza has only 163 MW. Area C obsesses over 62% of solar energy potential, while about 75% of the potential in area (A+B) is upon the roof tops. It is expected, 98% of the total renewable energy potential is solar energy potential. Only 0.12% of the total A and B lands are suitable for producing solar electricity.
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The book analyses human entomophagy and the need for using insects s food in the industrialized countries.
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Currently, there is a great interest in finding alternative protein and energy sources to replace soybean-based feeds in poultry diets. The main objective of the present study was to completely replace soybean in layer diets with defatted meal and fat from black soldier fly larvae without adverse effects. For this purpose, 5 × 10 Lohmann Brown Classic hens were fed either a soybean-based diet or diets based on defatted black soldier fly larvae meal and fat from 2 producers (1 commercial, 1 small-scale) operating with different rearing substrates, temperatures, and larvae processing methods (10 hens/diet). The data obtained included nutrient composition of larvae meals and diets, amino acid digestibility (6 hens/diet), and metabolizability, performance and egg quality (all 10 hens/diet). In addition, the acceptance of the 4 larvae-based diets was tested against the soybean-based diet in a 6-d choice feeding situation (10 hens/treatment). The nutritional value of the larvae-based diets was equivalent to the soybean-based diet in hens with a laying performance of 98%. Although average feed intake was not significantly different over the 7 experimental wk, the diets based on larvae feeds from the small-scale production appeared to be slightly less accepted in a choice situation than the soy-based diet and those with larvae from commercial origin. This was more likely the effect of the larvae fat rather than that of the larvae protein meal. In addition, the commercial larvae material was superior to that from the small-scale production concerning supply with digestible sulfur-containing amino acids (548 vs. 511 mg/d) and lysine (792 vs. 693 mg/d), egg weight (67 vs. 63.2 g), daily egg mass (66 vs. 61 g/d) and, in tendency, feed efficiency. The results indicate that soybean-based feeds can be replaced completely by black soldier fly meal and fat in diets of high-performing layers. However, because of nutritional differences between the larvae materials of different origin the quality of the larvae has to be closely monitored before being used.
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Introduction The main aim of the present review is to describe the advantages of using honey for general population and for athletes during endurance training, and to show its benefits as a healthy natural product, used as a huge energy source for human body. Conclusion Honey represents a sustainable and a natural food source which offers many advantages and health benefits through its antioxidant properties, antibacterial and antiseptic effects, as well as antifungal activity. Due to its properties and health benefits, an alternative medicine branch based on honey, called apitherapy, was developed during the last decades.
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In the present study, the complete cycle of the preconsumer waste transition by black soldier fly larvae (BSFL) into sustainable raw material (dietary fat) for broiler chickens was examined. In two individual experiments, the effect of selected rearing medium made from various preconsumer wastes on the nutritive value and performance of BSFL were tested (1st trial). In the second experiment, partial (25, 50, or 75%) or total replacement of soybean oil fed to broiler chickens by BSFL fat obtained via supercritical CO2 extraction from larvae from the 1st experiment was conducted. In the performance trial on birds, nutrient digestibility, selected gastrointestinal tract (GIT) segments, internal organ traits, and welfare status were also measured. In the first trial, 1-day-old BSFL were allotted to 5 treatments (8 replicates each). The following substrates were tested, i.e., wheat bran, carrots, cabbage, potatoes, and a mixture of the previouslymentioned organic food wastes (equal ratio of each). In the second experiment, a total of 960 day-old female Ross 308 chicks were randomly assigned to 5 dietary treatments (16 replicates and 12 birds per replicate). The following groups were applied: SO – 100% soybean oil, HI25 – a mixture containing 25% BSFL fat and 75% SO, HI50 – addition of BSFL and SO in a 50:50 ratio, HI75 – a mixture containing 75% BSFL fat and 25% SO, and HI100 – 100% BSFL fat. The results of the present study showed high variability in the chemical composition of insects among groups (410 vs. 550 g kg-1 CP; 60 vs. 170 g kg-1 EE), as well as a significant influence of rearing substrate composition on BSFL performance, i.e., the average mass of 100 randomly chosen larvae (P < 0.001), waste reduction rate (P < 0.001), and conversion rate (P = 0.008). Moreover, the partial or total replacement of SO by BSFL fat did not affect (P > 0.05) the growth performance, coefficients of apparent ileal digestibility of nutrients, selected organ weights and length, or the welfare status of the broilers. In conclusion, it is possible to obtain an environmentally friendly, sustainable energy source from BSFL biomass and implement it in broiler diets without a negative effect on the birds’ production.
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Known data on (the distribution of Hermetia illucens (L.) in Europe are summarized and updated. This species has been reliably recorded from Portugal, Spain, France, Switzerland. Italy, Malta, Croatia and Albania. A new record from Turkey represents the eastern most finding in the West Palaearctic and a new species to the fauna of the whole of the Near East. It may be evidence of a recent extension of this species in the Mediterranean area.
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Las larvas del picudo del cocotero Rhynchophorus palmarum L. (Coleoptera: Curculionidae) juegan un rol importante comofuente de proteínas para los indígenas amazónicos y constituye un alimento apetecible para estas poblaciones. Los indígenas las colectan de los tejidos de palmeras descompuestos y luego se los comen directamente o hervidos. En este artículo se describe un sistema no intensivo de cría, disponible para su desarrollo por las comunidades. Las larvas se criaron usando plantas silvestres y de cultivos agrícolas indígenas. Se estudió la supervivencia y la densidad larvaria en cada substrato de palmera. También se estudió: a) la composición nutricional de la larva, b) la composición nutricional de las palmeras Maximiliana regia Mart.(Cucurito), Jessenia bataua Mart. (Seje) y el Mauritzia flexuosa L. (Moriche) y, c) se realizó una prueba de palatibilidad conturistas. Palabras Clave: Composición nutricional, Rhynchophorus palmarum, Maximiliana regia, Jessenia bataua, Mauritzia flexuosa,insectos como alimento, dieta indígena amazónica. ABSTRACT The larvae of the Rhynchophorus palmarum L. (Coleoptera: Curculionidae) palm weevil play an important role as a source ofprotein for the Amazonian Indians, and are viewed as a tasty food by the population of the tropical Amazonian areas. These larvae make up a valuable resource for the Indian population. The Indians collect them from rotten palm stems and eat themboiled or raw. In this paper we describe the development of a small-scale growing system to be used by the rain forest Indiancommunities. Larvae are bred using wild plants and traditional Indian crops. We study larval survival and density in each palmsubstrate. We also studied: a) the larvae's nutritional composition, b) the nutritional composition of the Cucurito, Seje andMoriche palm substrata, and c) make a taste test with tourists. Key words: Nutritional compostion, Rhynchophorus palmarum, Maximiliana regia, Jessenia bataua, Mauritzia flexuosa,insect as food, amazonian
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Proximate composition of housefly maggot (Musca domestica) meal produced from decomposition of mixture of whole undiluted blood (WUB) and wheat bran (WB) was evaluated to determine the crude protein, amino acids, crude fibre, ether extract, and ash contents. Results revealed that maggot meal contains 47.1% crude protein, 25.3% fat, 7.5% crude fibre and 6.25% ash at dry matter level of 92.7%. The amino acid profile showed that maggot meal contains 17 amino acids among which are nine essential amino acids. Tryptophan was not identified. The most limiting essential amino acids, lysine and methionine were found to be higher in the maggot meal (6.04% and 2.28% respectively) when compared with those of other conventional protein sources including fish meal. It also revealed a balanced Leucine/Isoleucine ratio.
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By means of standardized methods, the nutritive value of some beetle species that are eaten in Mexico and that of Pachymerus nuclcorum from Brazil was analyzed and compared. It is concluded that the edible beetles of Mexico and P. nucleorum show a high nutritive value in proteins, amino acids, fats, calories, and minerals. Their ingestion contributes to the nutrition of the people that use this kind of food resource, in accordance with their abundance during several seasons of the year when they are available.
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Black Soldier Fly EXECUTIVE SUMMARY Previously reported work has shown that black soldier flies (Hermetia illuscens) are effective in reducing the mass as well as the nutrient and moisture content of hen manure. Preliminary results from using the black soldier fly to digest swine manure solids suggested that the system could be even more effective for swine manure. A small scale system for digesting swine manure solids, harvested by a belt beneath a slatted floor holding pigs, was installed and tested. Manure mass was reduced 56% while the concentrations of most elements and nutrients were reduced 40 to 55 %. Nutrient analyses and feeding studies indicate that dried black soldier fly prepupae grown on swine manure solids have value as a feedstuff, particularly for aquaculture. In a pot study, plant growth was increased when the digested manure residue was added to either a clay soil or clean sand.
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Seventeen species of edible insects representing nine families from south western Nigeria were analyzed for nutrient composition. They include the orders of Orthoptera, Lepidoptera, Coleoptera, Hymenoptera, and Isoptera. Analeptes trifasciata, Rhynchophorus phoenicis and Zonocerus variegatus has the highest crude protein content (29.62, 28.42 and 26.8%, respectively). The Ether Extract content ranged from 1.50 to 31.40%, and the highest amount was found in R. phoenicis (31.4%), Macrotermes bellicosus (28.2%) and Macrotermes notalensis (22.5%). The nitrogen free extract content ranged from 38.5 to 85.3%, with highest values in Brachytrypes spp. and Oryctes boas. The insect richest in Vitamin A, B 2 and C was Apis mellifera (12.44 ug/100 g, 3.24 mg/100g and 10.25 mg/100 g, respectively). Highest calcium and phosphorus contents of 61.28 mg/100g and 136.4 mg/100g were found in Analeptes trifasciata. Iron was found highest in M.notalensi and magnesium in Zonocerus variegatus. These insects which are sources of delicacy are also pests of certain crops at developmental stages of their life. Despite this they constitute a significant component of diet among the people of south western Nigeria.
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Samples of four insects cooked according to traditional methods in central Angola, were analysed by approved chemical and microbiological techniques. The quality of the proteins was evaluated by several chemical indices. The larvae of Usta terpsichore had the greatest potential nutritional value but the other insects were also useful sources of nutrients.
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Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae) may contribute to clarify the circumstances of a suspicious death and help to estimate the post-mortem interval. This species has been used as a forensic indicator of human corpses in USA [1,2]. In Europe, it was used for first time in 2001, in Italy [3]. The black soldier fly is originally a New World species, but food and other materials transported by man have resulted in the establishment of this species in all regions [4]. It is now widely distributed from approximately latitude 468N to 428S [4–7]. In Europe, it was recorded in Malta for the first time in 1926 [8], and since then it has been found in other parts of the Mediterranean region [4,9], Albania, Croatia, France, Italy, southern Switzerland, Portugal and Spain [10]. In the Iberian Peninsula, H. illucens was first recorded in 1954 from the eastern coast [11], and it was captured in Portugal for the first time in 1995 [12]. However, it has never been found breeding in animal remains or reported in faunistic studies of the sarcosaprophagous community in the Iberian Peninsula [13,14]. Adults probably feed on nectar and pollen, but they can survive for several weeks without food in laboratory conditions [15]. By contrast, larvae can use a wide variety of organic materials as food, but are mainly saprophages in media as diverse as manure or decaying fruits and vegetables, moreover, occasionally causing facultative human myiasis [16,17]. The case described here constitutes the first record of H. illucens breeding on human carrion in Spain. Furthermore, some notes on the biology and geographic distribution of H. illucens in the Iberian Peninsula are presented. This information could, in the future, help to estimate the minimum post-mortem interval in cases of suspicious death in the Mediterranean region. 1. Materials and methods Forensic case report. The body of an elderly man (72 years old) was found on the tiled roof of a farmhouse, located in a rural environment in Reus (N 41.108, E 1.068, Tarragona province, NE Spain) on 26 October 1998. The man had been last seen alive on the day of his disappearance, 8 November 1997. The body was lying face down (Fig. 1), covered by pine foliage and dressed in the same jeans, jacket, T-shirt, socks and shoes as had been worn when he was last seen. The cadaver exhibited mummification in soft tissues and partial skeletisation of the face and the upper part of the thorax. Insects were collected during the autopsy at the Instituto Anató mico Forense in Madrid and preserved in 70% ethanol prior to identification [18]. Meteorological data recorded at the weather station nearest to Reus showed an average daily maximum temperature in July 1998 of 26.9 8C, an average daily minimum temperature in January of 11.6 8C and overall average daily temperature of 17.6 8C. Based on investigations by the forensic medical examiner and police, the death was considered most likely to be on the date of disappearance. At the time of the post-mortem examination, samples of insects from around or under the body were not analysed. This article presents the first record of Hermetia illucens larvae on a human corpse in Spain (the second case report in Europe). Prepupae of H. illucens, and other insects, were recovered from the dead body of a 72-year-old man in an advanced stage of decomposition. The body was located in Reus (NE Spain), in October 1998. This article provides additional biological data on experimental studies and an update on the geographic distribution of this species in the Iberian Peninsula.
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Larvae of Calliphora vicina R.-D. (Diptera: Calliphoridae) hatching from eggs laid by adult females exposed to short day length, and then raised in darkness at 11oC, normally enter diapause rather than undergoing prompt pupariation. However, if the feeding stage is curtailed by premature extraction of larvae from their food, or if the larvae are subjected to severe overcrowding, smaller larvae side-step the diapause programme to become miniature puparia, whereas larger larvae proceed to diapause as fully-fed ones. In addition, smaller diapausing larvae show a shorter (or less intense) diapause than full-sized larvae. Apart from the smallest individuals, flies can emerge from these miniature puparia and in some cases are capable of laying eggs; this suggests that avoidance of diapause may allow undersized individuals an opportunity to reproduce before winter sets in. Fat determinations performed on larvae and pupae of various sizes, however, showed that short-day (diapause-destined) individuals lay down the same proportion of fat as long-day (non-diapause) individuals, and the same proportion of fat across all size classes. The possible functional significance of this phenomenon is discussed.
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Insect Biodiversity: Science and Society brings together leading scientific experts to assess the impact insects have on humankind and the earth's fragile ecosystems. It examines why insect biodiversity matters and how the rapid evolution of insect species is affecting us all. Insects and related arthropods make up more than 50 percent of the known animal diversity globally, yet a lack of knowledge about insects is hindering the advance of science and society. This book explores the wide variety in type and number of insect species and their evolutionary relationships. Case studies offer assessments on how insect biodiversity can help meet the needs of a rapidly expanding human population, and also examine the consequences that an increased loss of insect species will have on the world. The book concludes that a better understanding of the biology and ecology of insects is the only way to sustainably manage ecosystems in an ever changing global environment.
Article
The effects of replacing 0, 33.3, 66.7 or 100% of dietary fish meal (9%) with housefly maggots (Musca domestica. Linn) was investigated using broilers from day old to 5 weeks of age. Increasing the dietary level of maggots reduced feed intake and weight gain while increasing the feed: gain ratio (P>0.05), There was however no significant effect of dietary maggots on mortality rate (P>0.05). Replacement of dietary fish meal with maggots caused significant reduction in nitrogen retention (P<0.05) but an increase in fat retention (P>0.05). There was no significant effect of replacing dietary fish meal with maggots on the metabolizable energy value of the diets (P>0.05). It is concluded that maggots could replace only 33% of dietary fish meal (9%) without compromising performance and nutrient retention in broiler chicks. The cost of harvesting and processing maggots is about 15% of equivalent weight of fish meal, making even partial replacement of fishmeal with maggots economical.
Chapter
This chapter reviews the path leading to the present knowledge concerning the biodiversity of terrestrial arthropods and the questions raised along the way by both fieldwork and theoretical approaches. Then, it offers plans that will lead directly to a resolution of the biodiversity question, if money and effort are seriously applied to the endeavor. After two and a half centuries of inquiry, we still do not have the crucial answer regarding most of Earth's biota: How many species of terrestrial arthropods are there? As it has been pointed out, we are not even close to knowing the order of magnitude of species on Earth. Recently, at various meetings both in the systematics and conservation communities, some researchers have argued that the question is not important, but rather our energy must go to conserving whatever is out there. Others have argued that the question itself is not helpful scientifically. Those who oppose these two arguments have marshaled various arguments of their own. For example, if we don't know it and where it lives, we cannot save it. Others believe that the actual number does not matter; the academic pursuit of all knowledge is important.
Article
Terrestrial insects belonging to 8 species groups were collected from 5 sites in A.B.U. main campus and analysed for nutritional constituents using standard biochemical methods. The highest level of crude protein was found in Catarrtopsilus taeniolatus (40.57%) and the lowest in Microtermes sp (24.85%). Crude protein and lipid contents varied significantly (P<0.05) between the species groups. Differences between the crude protein content of Zonocerus variegates specimens was not significant (P>0.05) and decreased in the order nymph> winged adult> de-winged adult. Carbohydrate (LSD(0.05) =1.09) and crude fibre (LSD(0.05) = 0.79) also varied significantly between the groups. The ash content ofMicrotermes sp was about 4 times higher than the level in any other species group. The significance of these nutrients and their role as suitable substitutes and supplements in human and livestock diets are discussed.
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The production of fatty acid methyl esters (FAME) from crude tobacco seed oil (TSO) having high free fatty acids (FFA) was investigated. Due to its high FFA, the TSO was processed in two steps: the acid-catalyzed esterification (ACE) followed by the base-catalyzed methanolysis (BCM). The first step reduced the FFA level to less than 2% in 25 min for the molar ratio of 18:1. The second step converted the product of the first step into FAME and glycerol. The maximum yield of FAME was about 91% in about 30 min. The tobacco biodiesel obtained had the fuel properties within the limits prescribed by the latest American (ASTM D 6751-02) and European (DIN EN 14214) standards, except a somewhat higher acid value than that prescribed by the latter standard (<0.5). Thus, tobacco seeds (TS), as agricultural wastes, might be a valuable renewable raw material for the biodiesel production.
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Characterization of solar collectors is based on experimental techniques next to validation of associated models. Both techniques may be adopted assuming different complexities. In this work, a general methodology to validate a collector model, with undetermined associated complexity, is presented. It serves to characterize the device by means of critical coefficients, such as the film (convection) transfer coefficient, plate absortance or emmitance. The first step consists of identifying those significant parameters that match the selected model with the experimental data, via nonlinear optimization techniques, applied to steady state conditions. Second, new correlations must be adopted, in those terms where it is necessary (i.e. film coefficient equations). Finally, the overall model must be checked in transient regime. To illustrate the technique, a tailor-made prototype flat plate solar collector has been analyzed. An intermediate complex collector model has been proposed (2D finite-difference method). Both steady and transient states were analyzed under different operating conditions. Parameter identification is based on Newton's method optimization. For parameter approximation, exponential regression functions through multivariate analysis of variance is proposed among many other alternatives. Results depicted a robustness of the overall proposed method as starting point to optimize models applied to solar collectors.
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Recently, the inverse depth parameterization has been widely used in monocular simultaneous localization and mapping (SLAM) within the standard extended Kalman filter (EKF) framework. However, the feature depth is not able to be estimated at one observation. In fact, the feature depth and its standard deviation are initialized empirically, which may affect the convergence of the standard EKF. In order to improve the performance, a modified covariance extended Kalman filter (MVEKF) is proposed in this paper. Loop closure tests are performed to compare the proposed method with the standard EKF method and the results show that the MVEKF method is more robust to the uncertainty of the initial depth estimation while the computational complexity remains about the same.
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Biodiesel is a promising alternative diesel fuel which has increased worldwide public interest in a number of countries including China. But the high cost of producing biodiesel from feedstock, predominately food grade oils, limited its economic feasibility. An alternative of using grease extracted from restaurant waste to produce biodiesel is a potential low cost approach. However, this approach generates a significant large quantity of solid residual fraction which required proper disposal. This study was conducted to evaluate the potential of a secondary biodiesel production from the solid residual fraction of restaurant waste after typical grease extraction (SRF) employing a high fat containing insect, black soldier fly, Hermetia illucens. The SRF was sampled and fed to black soldier fly larvae. The resulting larval biomass was used for crude grease extraction by petroleum ether. The extracted crude grease was then converted into biodiesel by acid-catalyzed (1% H2SO4) esterification and alkaline-catalyzed (0.8% NaOH) transesterification. About 23.6 g larval grease-based biodiesel was produced from approximately 1000 larvae grown on 1 kg of SRF. The weight of SRF was reduced by about 61.8% after being fed by the black soldier fly larvae for 7 days. The amount of biodiesel yield from restaurant waste was nearly doubled (original restaurant waste grease, 2.7%; larval grease, 2.4%). The major methyl ester components of the biodiesel derived from black soldier fly larvae fed on SRF were oleinic acid methyl ester (27.1%), lauric acid methyl ester (23.4%), and palmitic acid methyl ester (18.2%). Most of the properties of this biodiesel met the specifications of the standard EN 14214, including density (860 kg/m3), viscosity (4.9 mm2/s), flash point (128 °C), cetane number (58) and ester contents (96.9%). These results indicated that black soldier fly larval biomass obtained from larvae reared on SRF could potentially be used as a non-food feedstock for biodiesel production. This approach not only enhances the efficiency of biodiesel production from restaurant waste, it also helps to better manage and significantly reduce the large quantity of solid residual fraction produced during the process of biodiesel production using restaurant waste.
Article
Seventy-eight species of edible insects, representing twenty-three families from the state of Oaxaca in Mexico, were analyzed for nutrient composition. They include the orders of Anoplura, Diptera, Orthoptera, Hemiptera, Homoptera, Lepidoptera, Coleoptera, and Hymenoptera. The dry basis protein content ranged from 15 to 81%. The highest was found in a wasp of the genusPolybia.Fat content ranged from 4.2% (several grasshopper species:Boopedon flaviventris, Sphenarium sp., Melanoplus mexicanus) to 77.2% in the larvae of a butterflyPhasus triangularis.The insect richest in carbohydrates was the antMyrmecosistus melligerwith 77.7%. The amino acid profile of the studied insects compares with the preschooler and adult requirements indicated in 1985 by the F.A.O. and the W.H.O. Their protein chemical score (corresponding to the capacity for fulfilling the requirement of the most limiting essential amino acid) ranged from 46 to 96%; in a few cases there were deficiences of tryptophan and lysine. Protein digestibility varied between 76 and 98% for the species analyzed. The caloric contribution varied from 293 to 762 kcal/100 g, the highest value also being for the butterfly larvae ofPhasus triangularis.Constituting a significant component of the diet of some rural communities in Oaxaca, consumption parameters vary depending on the species, season, habitat, climate, and biotope. Eaten daily in some regions, insects are roasted, fried, or incorporated into a ragout dish, generally in the immature stage. Hymenoptera (ants, bees, and wasps) are preferred for consumption.
Article
Biodiesel is a renewable fuel comprised of fatty acid methyl esters (FAME) derived from vegetable oils or animal fats. Comparisons between biodiesel and petroleum-based diesel have shown biodiesel to be effective in reducing exhaust emissions of carbon monoxide, hydrocarbons, particulate matter, and sulfur dioxide. While there are advantages of biodiesel over the traditional petroleum based diesel, biodiesel commercialization is limited by production cost that is dominated by the price of the feedstock (soybean oil). Yellow grease has the potential to be an effective feedstock with lower cost, but the chemical composition of these oils is variable depending on the source of collection and differs from that of virgin oil due to the presence of free fatty acids (FFA). Esterification has been previously demonstrated to reduce the FFA levels of YG; however, large quantities of methanol were required to drive the reaction to high yield. Methanol usage for processing and FFA content are the main factors affecting the economics of FAME production from YG. In this study, the relationship between composition and process variables was systematically studied. The effect of FFA ranging from 2% to 32% (w/w) was studied at three different molar ratios of methanol to FFA (4.5:1, 9:1, 18:1) and was found to have a non-linear relationship. Data obtained from this full factorial screening was used to develop a predictive statistical model to forecast the conversion based on initial FFA level and proportion of alcohol applied for esterification.
1.1. The proteins of the larval fat body of the southwestern corn borer, Diatraea grandiosella, were subjected to isoelectric focusing and disc electrophoresis in polyacrylamide gels to examine the diapause-associated protein (DAP).2.2. The fat bodies of last instar pre-diapausing larvae, as well as those of non-diapausing larvae which had been treated with juvenile hormone or a juvenile hormone mimic, were shown to store DAP.3.3. The protein fraction has an isoelectric point of 5.9, and appears to be a single polypeptide unit with a molecular weight of about 35,000.4.4. The protein was resistant to hydrolysis at 37°C by midgut enzymes and trypsin.5.5. De novo synthesis of DAP was demonstrated both in vitro and in vivo in the fat body of pre-diapausing larvae using radioactive leucine.6.6. Isolated fat bodies of 33-day old last instar pre-diapausing larvae incubated in macromolecule-free Grace's medium incorporated [3H]leucine selectively into DAP.7.7. Experiments employing [14C] and [3H]leucine and cycloheximide, an inhibitor of peptide bond formation, confirmed the synthesis of DAP in vivo.8.8. DAP was released unchanged from the fat body of mid-diapausing larvae in vitro. Since the protein does not accumulate in the haemolymph in vivo it may be structurally modified before or after release in vivo.9.9. The possible diapause-related functions of DAP are appraised.
1.1. The fatty acid compositions of the seven insect orders, Lepidoptera, Hemiptera, Orthoptera, Diptera, Hymenoptera and Dictyoptera differ quantitatively in a number of respects with regard to the relative percentages of the commonly occurring fatty acids, myristic, myristoleic, palmitic, palmitoleic, stearic, oleic, linoleic and linolenic acids.2.2. Major characteristics which appear to be taxonomically related include the relatively high levels of palmitoleic acid in dipterous insects and high levels of myristic acid in some families of hemipterous insects. The exceptions are discussed.3.3. The apparent significance of the fatty acid composition, in general, is discussed.
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Biodiesel has become more attractive recently because of its environmental benefits and the fact that it is made from renewable resources. The cost of biodiesel, however, is the main hurdle to commercialization of the product. The used cooking oils are used as raw material, adaption of continuous transesterification process and recovery of high quality glycerol from biodiesel by-product (glycerol) are primary options to be considered to lower the cost of biodiesel. There are four primary ways to make biodiesel, direct use and blending, microemulsions, thermal cracking (pyrolysis) and transesterification. The most commonly used method is transesterification of vegetable oils and animal fats. The transesterification reaction is affected by molar ratio of glycerides to alcohol, catalysts, reaction temperature, reaction time and free fatty acids and water content of oils or fats. The mechanism and kinetics of the transesterification show how the reaction occurs and progresses. The processes of transesterification and its downstream operations are also addressed.
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Mixing is very important to the transesterification of beef tallow, because melted beef tallow and a sodium hydroxide–methanol solution (NaOH–MeOH) are immiscible. There was no reaction without mixing. When NaOH–MeOH was added to the melted beef tallow in the reactor while stirring, stirring speed was insignificant. Reaction time was the controlling factor in determining the yield of methyl esters. This suggested that the stirring speeds investigated exceeded the threshold requirement of mixing. When NaOH–MeOH was added to the melted beef tallow without stirring, higher stirring speeds or longer stirring times were needed to mix the two phases subsequently. In both cases, once the two phases were mixed and the reaction was started, stirring was no longer needed. Misek's equation was applicable to the former case. The droplet diameter was inversely proportional to the square of the rotation speed. But in the latter case, the droplet diameter was inversely proportional to n1.2. S