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Challenges in Development of Gluten-Free Breads
Abstract
Gluten-free bread making is a challenging task as the ingredients used could not mimic wheat gluten functionality. Gluten protein complex is considered vital for successful bread making. Commercially available gluten-free breads face both social and scientific challenges in comparison to conventional gluten-containing counterparts in terms of quality and acceptability. Doughs derived from gluten-free flours exhibit poor rheological properties and the resultant breads are characterized by sensory and nutritional defects. Addition of starches, hydrocolloids, proteins, enzymes, and emulsifiers to gluten-free flours are encouraged in order to counter the technological problems by enhancing dough rheological characteristics. Gluten-free bread (GFB) from nutritional point of view, lacks protein, vitamins and minerals and effective ways are required to be explored to enhance the fibre, protein, vitamin and mineral content of GFB while maintaining low glycaemic index. Fortification of GFB with alternate flours such as flours from pulses, gluten-free cereals like millet, rice, sunflour etc., bran or dietary fibre, nuts, pseudocereals or any oil seed is therefore recommended.
... Microwave treatment of maize flour has been found to alter its microstructure, physicochemical characteristics, and pasting properties, affecting its functional properties and thermal behavior [14]. The microwave radiation treatment increases the hydration properties and particle size of the flours, resulting in lower viscosities and higher pasting temperatures [6]. Additionally, the treatment leads to a structuring and stabilizing effect on the flours, resulting in an increase in the viscoelastic moduli and maximum stress that the gels can withstand [15]. ...
... Gluten-free diets, once a medical necessity for individuals with celiac disease, have become increasingly popular among the general population, leading to a surge in the demand for gluten-free foods, particularly bread [1][2][3][4][5]. However, a common critique of commercial gluten-free breads is their compromised nutritional quality when compared to their gluten-containing counterparts [6]. Many gluten-free bread formulations rely heavily on starch-fiber mixes, which may lack essential nutrients and bioactive compounds that are present in whole grain flours [7]. ...
... That behavior shows the importance of specific agent additions in gluten-free bread made from native gluten-free flours. The clean label trend forces the removal of all additives, which challenges the bread baking industry [6]. The addition of buckwheat native flours reduced the bake loss by 15% and 19% for Polish and Spanish samples, respectively. ...
Currently, the market for gluten-free products is experiencing a significant growth due to, mainly, the increase in the number of gluten-intolerant patients diagnosed and to the merging of a new niche market for consumers who optionally avoid gluten. Native flours are perceived as viable alternatives for industrially used starch and hydrocolloids blends, which lack in the vitamins and minerals that are in abundance in non-refined raw materials. This study delves into the potential of microwave technology in enhancing the functional and nutritional attributes of gluten-free breads. The research was conducted by employing 900 W microwave power for 8 min for buckwheat and teff flours modification with an initial moisture content of 30%. The modified flours were blended with rice flour and baked to verify the potential of microwave high moisture treatment for adjusting the texture and nutritional quality of the bread. The results revealed that microwave treatment of flours helped in retaining a higher level of essential nutrients and bioactive compounds in gluten-free breads.
... So different ingredients are used to imitate the viscoelastic properties of gluten to avoid these defects and achieve quality characteristics similar to wheat bread. For this purpose, hydrocolloids, fibres and proteins of various origins are widely used (Roman et al., 2019;Manzoor et al., 2021;Mir et al., 2021). Consequently, it is expected that due to its composition soybean okara could be included in a gluten-free formulation to achieve this purpose. ...
The production of soybean protein isolates generates an insoluble residue called okara that is rich in proteins and dietary fibre. These macromolecules have functional properties that can be modified and improved by emerging technologies, such as high‐intensity ultrasound. The objectives of this work were to analyse the ability of soybean okara (UOK) to act as a gluten‐free bread improver and to evaluate the effect of a sonication process on this property (OKS). Both okaras were assayed at two percentages (2% and 3%) leading to a reinforcement of interactions in the matrix of batters, producing bread of better technological and sensorial quality. The addition of OKS 3%, improved specific volume (20%), reduced the hardness (30%) and increased the cohesiveness of the crumb and improved the air inclusion. These results demonstrated the efficiency of the sonication process to obtain a gluten‐free bread improver from a bulky by‐product of the soybean industry.
Recently, marine hydrocolloids have gained interest as a potential future food additive in baking and other food industries. Studies have shown the potential of marine hydrocolloids as functional ingredients to improve the bread quality. In this regard, the review summarizes the applications of marine hydrocolloids (carrageenan, agar, alginate) in improving bread's rheology and overall functionality. The review also provides an overview of marine hydrocolloids' physicochemical and functional characteristics, focusing on their usage as thickening agents, stabilizers, emulsifying agents, and viscosity modifiers. Additionally, the applications of marine hydrocolloids in improving the bread dough quality, texture, stability, and nutritional value are also discussed. Moreover, marine hydrocolloids' role in lowering the glucose digestion rate, resulting in a low glycemic index, has been described. Marine hydrocolloids can be a safe and healthy option for developing novel bakeries and other food products. Therefore, future research should be directed to characterize and explore the key applications and digestion mechanisms of marine hydrocolloids to meet the demand of the food sector for novel functional food products.
Effect of hydrothermal modifications (autoclaving, annealing and heat moisture treatment) on physico-chemical, rheological properties and in vitro digestibility of kithul starch was studied. Annealing and heat moisture treatment decreased swelling index, solubility and increased crystalline properties as compared with autoclaving. Autoclaving, annealing and heat moisture treatment caused significant morphological damages such as large holes and fissures on the kithul starch, in addition, granules changed from oval to donut shape. Heat moisture treatment formed higher number of agglomerated starch granules. Light transmittance decreased after hydrothermal modifications. Autoclaving and annealing increased the pasting viscosities (except break down viscosity) of kithul starch. A significant increase (p ≤ 0.05) in peak temperature, conclusion temperature and enthalpy was found in annealed and heat moisture treated kithul starches. The digestibility of kithul starch decreased with increasing resistant starch after annealing and heat moisture treatment. Autoclaved, annealed and heat moisture treated kithul starches exhibited higher value of storage modulus (G′) and loss modulus (G″) than native kithul starch. It entail to higher firmness of modified starch gel. The current study showed that the remarkable changes formed by hydrothermal modifications increased the industrial acceptance of kithul starch.
Kithul starch was subjected to annealing, heat moisture treatment, cross-linking, annealing after cross-linking and heat moisture treatment after cross-linking and its physico-chemical, functional properties and in vitro digestibility was studied. Moisture and amylose content significantly (p ≤ 0.05) reduced after modifications. Phosphorus content of kithul starch increased after cross-linking. X-ray diffraction pattern (type A) did not change and crystalline properties increased after modifications. HLS (cross-linked heat moisture treated kithul starch) showed highest relative crystallinity among the modified starches. Swelling index, solubility and light transmittance decreased after modifications. Single and dual modifications caused severe damages such as fissures and holes on the granular surface. Peak viscosity of ANS (annealed kithul starch), CLS (cross-linked kithul starch) and ALS (cross-linked annealed kithul starch) increased and HMS (heat moisture treated kithul starch) and HLS (cross-linked heat moisture treated kithul starch) decreased as compared with NS (native kithul starch). Modified kithul starches showed lower break down viscosity and higher set back and final viscosity. Rheological analysis showed higher hardness of modified starch gel (higher storage and loss modulus) as compared with NS gel. In vitro digestibility decreased after modifications and HLS showed higher resistant starch (RS). Gelatinization temperature varied after modifications. Enthalpy of gelatinization significantly increased after single and dual modifications.
Physico‐chemical, retrogradation, rheological properties and in vitro digestibility of lysine incorporated kithul starch modified by annealing, heat moisture treatment and its combinations were studied. LS‐AHMT (annealed‐heat moisture treated lysine incorporated kithul starch) exhibited lowest amylose leaching. LS‐AHMT showed significantly (P ≤ 0.05) higher relative crystallinity. LS‐ANS (annealed lysine incorporated kithul starch), LS‐HMT (heat moisture treated lysine incorporated kithul starch) and LS‐AHMT formed more weak gel by the effect of annealing, heat moisture treatment and its combination. LS‐AHMT showed lowest pasting viscosities, G′ and G″ values among the modified kithul starch, which indicates its lower retrogradation properties. In vitro digestibility of kithul starch decreased after modifications and LS‐ANS, LS‐HMT and LS‐AHMT showed significantly higher resistant starch content. The current study showed that annealing, heat moisture treatment and its combination on NS‐LS (lysine incorporated kithul starch) effectively modified kithul starch properties.
The main wheat component responsible for bread and cake quality is gluten. Celiac disease is an autoimmune digestive disease that is caused by the digestion of gluten, and the only treatment of this disease is a gluten‐free diet. Various gluten‐free formulations (composite and wheatless flours) have applied gums (as gluten substitutes) to mimic the viscoelastic properties of gluten. In the bakery products, gums have been used to improve dough performance, bread and cake characteristics, textural and sensorial quality, and extension the products shelf life. This paper reviews the effect of the most common and new hydrocolloids (balangu seed, wild sage seed, basil seed, cress seed, xanthan, guar, starch carrageenan, methylcellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, and locust bean gums) on the rheological, physicochemical, textural, and quality characteristics of gluten‐free breads and cakes. Gums affect gelatinization and retrogradation of starch through a strong association of amylose with gum, resulting in a decrease in the retrogradation of starch. Gums addition increased volume and porosity of the breads and cakes and resulted in softer products. This paper reviews the effect of the most common and new hydrocolloids (balangu seed, wild sage seed, basil seed, cress seed, xanthan, guar, starch carrageenan, methylcellulose, carboxy methyl cellulose, hydroxyl propyl methyl cellulose, and locust bean gums) on the rheological, physicochemical, textural, and quality characteristics of gluten‐free breads and cakes.
Buckwheat‐resistant starch (BRS) has shown to be a nutrient capable of lowering cholesterol and reducing obesity. In this study, the regulatory effects of tartary buckwheat starch on blood lipid level and gut microbiota (Lactobacillus, Bifidobacterium, Enterococcus, and Escherichia coli) in mice fed with a high‐fat diet was investigated. Male C57BL/6 mice were separately fed with a normal diet (CON), a high‐fat diet (HFD), and high‐fat diet supplemented with buckwheat‐resistant starch (HFD+BRS) for 6 weeks. After the feedings, lipid profile, blood glucose, plasma levels of cytokines, short‐chain fatty acid content in the colon and intestinal flora of fecal were measured. Furthermore, the antioxidant indices of the liver and duodenum tissues were measured to evaluate the antioxidant capacity of mice. Significantly reduced plasma levels of total cholesterol (TC), triglyceride (TG), glucose, and cytokines were observed in the HFD+BRS group, accompanied by an increased antioxidant capacity in the liver and duodenum. In addition, supplementation with BRS significantly inhibited the increase in plasma lipopolysaccharide, tumor necrosis factor‐α, and interleukin‐6 levels. Gut microbiota composition was regulated by the supplement of BRS, which promoted the growth of Lactobacillus, Bifidobacterium, and Enterococcus, as well as inhibited the growth of Escherichia coli. In contrast to the HFD group, the content of short‐chain fatty acids in mice colon increased in the BRS group. In conclusion, BRS benefited the cholesterol and glucose metabolism, as well as optimized gut microbiota composition in mice fed with a high‐fat diet.
Practical Application
This study identified the beneficial effects of tartary buckwheat‐resistant starch on the regulation of blood lipids and intestinal flora in mice fed a high‐fat diet. The result of this study will provide a basis for the development of probiotic products supplemented with tartary buckwheat‐resistant starch and direction for further research.
Gluten-free (GF) batters usually present several technological challenges that limit the performance during conventional baking and the resulting product quality. Due to the volumetric heating principle and faster heating rates, ohmic heating (OH) may be advantageous compared with conventional baking. Therefore, the potential of using ohmic heating as a novel approach for gluten-free bread baking was explored. In detail, the effect of different OH process parameters (power input, holding time) on the chemical and functional properties (specific volume, crumb firmness and relative elasticity, pore properties, color, starch gelatinization) and digestibility of breads was investigated. Results showed that GF breads could benefit from the uniform rapid heating during processing, as these breads showed superior functional properties (specific volume, 2.86–3.44 cm3/g; relative elasticity, 45.05–56.83%; porosity, 35.17–40.92%) compared with conventional oven-baked GF bread (specific volume, 2.60 cm3/g; relative elasticity, 44.23%; porosity, 37.63%). In order to maximize bread expansion and the OH performance, it was found that the OH process could be improved by applying the electrical energy in three descending power steps: first step with high power input (in this study, 2–6 kW for 15 s), followed by 1 kW for 10 s, and 0.3 kW for 1–30 min. In total, ohmic baking only needed a few minutes to obtain a fully expanded GF bread. The determination of pasting properties and starch digestibility demonstrated that these breads were comparable or even superior to GF breads baked in a conventional baking oven.
Gluten-related disorders are very common in pediatric patients. Wheat allergy is triggered by an immunoglobulin E (IgE)-dependent mechanism; its prevalence varies according to the age and region, and in Europe has been estimated to be lower than 1%. Many studies investigated the potential role of several external factors that can influence the risk to developing wheat allergy, but results are still inconclusive. It can be responsible for several clinical manifestations depending on the route of allergen exposure: food-dependent exercise-induced anaphylaxis (FDEIA), occupational rhinitis or asthma (also known as baker’s asthma), and contact urticaria. The prognosis of IgE-mediated wheat allergy in children is generally favorable, with the majority of children becoming tolerant by school age. Patients who experienced an anaphylactic reaction prior to 3 years of age and patients with higher level of wheat- or ω-5 gliadin-specific IgE antibodies seem to be at higher risk of persistent wheat allergy. The current management of patients is dietary avoidance. Nowadays, oral immunotherapy has been proposed for wheat allergy with promising results, even if further studies are necessary to establish the best protocol in order to promote tolerance in wheat-allergic children.
Crystalline, pasting and thermal properties and antioxidant activity of starch isolated from queen sago seed by using different isolation methods such as water steeping, alkali steeping and enzymatic extraction methods were evaluated. The properties studied include, chemical composition, morphology, swelling, solubility, color, X-ray diffraction (XRD), texture, pasting (RVA), total phenolic content, antioxidant activity and thermal (DSC) properties. Among the isolation methods, enzymatic extraction method is efficient as compared to alkali and water steeping method. Enzymatically extracted sago starch (ES) showed highest yield, L* value, swelling, solubility and lower non starch components. ES formed harder gel as compared to alkali steeped sago starch (AS) and water steeped sago starch (WS). SEM showed presence of more agglomerated granular structure in AS. ES showed highest peak, trough and break down viscosity. Setback and final viscosity was highest for AS. Isolation methods affected on the total phenolic content and antioxidant activity of queen sago seed starch. Highest gelatinization enthalpy of AS was correlated with higher relative crystallinity and presence of more agglomerated structure. The queen sago seed starch isolated by enzymatic extraction method has better properties and industrial relevance.
The market for gluten‐free products is steadily growing and gluten‐free bread (GFB) keeps on being one of the most challenging products to develop. Although numerous research studies have worked on improving the manufacture of GFBs, some have adopted approaches far from commercial reality. This review analyzes the ingredient list and nutrition facts of 228 commercially available GFBs produced by different brands around the world. The results from studying the ingredient list of breads revealed that commercial breads do not tend to use a single starchy source or gluten replacer, but a combination of several ingredients to optimize bread quality. Maize, tuber starches, and rice flour were the main starchy sources. Regarding hydrocolloids, the most often included ingredients were hydroxypropyl methylcellulose, xanthan and guar gum, and psyllium. Proteins and sugars were added, respectively, in 81% and 87% of the commercial breads analyzed. Furthermore, it was found that vegetable oils were preferred over fats. A long list of ingredients was observed in commercial GFBs, with the presence of a wide range of additives, including acidifiers, emulsifiers, leavening agents, preservatives, and aromas or flavorings. Meanwhile, nutrition facts showed a lower protein and higher fat content for GFBs compared to a gluten‐containing counterpart, with small differences for salt and sugar. This research expands the current knowledge on GFB manufacturing, giving a panoramic outlook on the current situation in the GFB market, and helping both scientists and gluten‐free companies unify/identify common trends.
The past 20 years has seen rapid development of value-added food products. Using largely wasted fruit by-products has created a potential for sustainable use of these edible materials. The high levels of antioxidant activity, phenolic compounds, dietary fibres and resistant starch in banana pulp and peel have made this tropical fruit an outstanding source of nutritive ingredient for enrichment of foodstuffs. Accordingly, processing of separate banana parts into flour has been of interest by many researchers using different methods (oven drying, spouted bed drier, ultrasound, pulsed vacuum oven, microwave, spray drying and lyophilization). Regarding the high level of bioactive compounds, especially resistant starch in banana flour, the application of its flour in starchy foods provides a great opportunity for product development, even in gluten free foods. This review aims to provide concise evaluation of the health benefits of banana bioactive components and covers a wide range of literature conducted on the application of different parts of banana and the flour produced at various ripeness stages in the food industry. Of particular interest, the impact of drying methods on banana flour properties are discussed.
Native cassava starch was gelatinized under different pretreatment conditions (preheating temperature, starch concentration and heating time) and spray-dried. A rotational compound central design was used to test the three independent variables: the preheating temperature, starch concentration, and heating time, and the behavior of the system was assessed by response surface methodology. The results showed a significant effect of both the preheating temperature and heating time on the cold viscosity. The combination of the preheating temperature and starch concentration affected the crystallinity, enthalpy change, solubility, and final viscosity. Modification by spray-drying resulted in a decrease in the crystalline regions, and enthalpy change, as well as an increase in the cold viscosity. The optimal conditions for obtaining partially gelatinized cassava starch with high cold viscosity and lower breakdown, desirable characteristics for commercial pregelatinized starch, are as follows: starch concentration of 25%, preheating temperature of 52 °C, and processing heating time of 10 min.
The aim of the present study was to investigate the influence of milling methods (jet mill (JM) and hammer mill (HM)) and wheat cultivars (Keumkang (K), Jokyung (J), and Anzunbaengi (A)) on physicochemical and dough properties of whole-wheat flour (WWF). The color, particle size, starch damage (SD), falling number (FN), water absorption index (WAI), water solubility index (WSI), pasting and Mixolab® properties, and dough extensibility of WWF were measured. Significant differences were observed in proximate compositions as well as in color, particle size, FN, and WAI between the distinct milling methods and cultivars ( p<0.001 ). The particle sizes of each cultivar milled with a HM (K: 188.5 µ m; J: 115.7 µ m; A: 40.34 µ m) were larger than those milled with a JM (K: 41.8 µ m; J: 50.7 µ m; A: 20.8 µ m). The final viscosity of WWF milled with a HM (K: 1304 cP; J: 1249 cP; A: 1548 cP) was higher than that of cultivars milled with a JM (K: 1092 cP; J: 1062 cP; A: 994 cP). Dough extensibility and resistance to extension also differed among the cultivars, and the C2 Mixolab® parameter (an indicator of protein weakening) was influenced by the milling method. Overall, results from principal component analysis showed that, among the three cultivars, Keumkang WWF was the most affected by the milling method.
Starch is the major component of kithul flour (66%) obtained from the trunk of kithul palm (Caryota urens). In this study, physicochemical, morphological, pasting and thermal properties of kithul flour and starch were compared. It is a high amylose starch (38.5%). Kithul starch has higher phosphorous content than some of the tubers and legume starches. Kithul starch is oval in shape with smooth surface and showed higher swelling index and solubility than flour. Kithul starch showed type A crystalline pattern with 34.2% relative crystallinity. Water and oil absorption capacity of kithul flour is higher than that of starch. Kithul starch showed higher pasting properties such as peak, trough, setback and final viscosity as compared to flour. Sharp increase in peak viscosity showed rapid swelling character of kithul flour and starch. As compared to flour, kithul starch gel has higher firmness. Kithul starch showed higher gelatinization (onset, peak and conclusion) temperature and enthalpy of gelatinization as compared to flour.
In this study, the content of bioactive compounds (polyphenols and tetraterpenoids), antioxidative activity, and inhibitory activities toward α-amylase, α-glucosidase, cholinesterase of different cultivars of peach kernels were measured. Such results have not been published so far. It has been shown that peach kernels were characterized by a similar profile of bioactive compounds as the peach fruit, however, the content of some of these compounds was completely different. The total content of polyphenols ranged from 12.7 to 3.8 g/100 g dm, the carotenoids contains were from 101.7 to 0.0 mg/100 g dm and the amount of cyanogenic glycoside ranged from 245.7 to 17.4 mg/100 g dm. The peach kernels were also characterized by high antioxidative potential and the ability to inhibit enzymes linked to obesity, type 2 diabetes and Alzheimer’s disease. The study showed that the health-promoting properties of peach kernels are stimulated by polymeric procyanidins, hydroxycinnamic acids, carotenoids and cyanogenic glycosides. Generally, it was confirmed that peach kernels could be a valuable source of polyphenols used by the pharmaceutical industry for the production of dietary supplements to support the prevention of chronic non-communicable diseases.
In this study, the fermented cassava-sweet potato-sorghum mixed flours have been used to produce GF bread using xanthan gum as substitute of gluten. The “constrained mixture design” was used to evaluate the effect of flour proportions on the rheological and textural properties of dough and bread. The pasting properties of flour blends reveal high peak viscosity (750–1076 cP) for blends containing more than 70% cassava flour. Sweet potato and sorghum flours lead to a drop in the peak viscosity in the blend when substituted at 30 and 20% respectively. According to the response surface of the Linear Visco elasticity (LVR G′), 5% of sorghum proportion appears as the critical threshold beyond which the decrease in the proportion of cassava flour makes it possible to increase the solid character of the dough (LVR G′ increases). Analysis of the textural properties (hardness, adhesiveness, elasticity, cohesiveness and chewiness) of the crumb of the fresh and stored breads allowed obtaining an optimal flour formulation made of 75% fermented cassava, 20% sweet potato flour and 5% sorghum. This study demonstrated feasibility of fermented cassava-sweet potato-sorghum mixed flours in GF bread making.
As a recyclable natural material, starch is an important raw material in food and other fields. The native starch by esterification could improve the performance of the original starch and expand its range of application. This article reviews the preparation process of acetylated distarch adipate, starch sodium octenylsuccinate, starch acetate, hydroxypropyl starch, and starch phosphate and research into the influence of starch esters on dough. At the same time, it forecasts the trend of starch esters and application prospect in the future research.
Advancement in technology and changing lifestyle demand reduction in baking time with good quality product. One of the ways to reduce the baking time is by introducing rapid heating modes such as microwave, infrared and jet impingement heating. However, use of such heating modes during the baking process may alter the final product quality such as surface colour, moisture content, crumb hardness and porosity. Energy efficiency and product quality are the prime factors for any process industry and combining two or more heating modes (hybrid heating) can yield the desired quality of baked product. Therefore, hybrid heating oven shows promise of providing energy and time efficient baking process. Use of hybrid heating requires a thorough knowledge of baking process along with biochemical and physical transformation. This review contents scientific papers published in the last 15 years mainly, dealing with various ovens and its hybrid heating modes used for the baking process are summarized along with the merits and limitations of these approaches.
Non-celiac gluten sensitivity (NCGS) is a condition characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing foods in the absence of celiac disease and wheat allergy. The diagnosis is cumbersome and currently confirmed only by gluten withdrawal and double-blind placebo challenge protocols. There is great overlap in symptoms between NCGS and other functional gastrointestinal disorders, making a differential diagnosis difficult. The pathophysiology of NCGS is largely unclear, and there are contrasting data on the trigger of this condition. This review will highlight the state-of-the-art knowledge on NCGS and the key open questions.
Management of coeliac disease (CD) requires the removal of gluten from the diet. Evidence of the availability, cost, and nutritional adequacy of gluten-free (GF) bread and pasta products is limited. GF flours are exempt from UK legislation that requires micronutrient fortification of white wheat flour. This study surveyed the number and cost of bread and pasta products available and evaluated the back-of-pack nutritional information, the ingredient content, and the presence of fortification nutrients of GF bread and pasta, compared to standard gluten-containing equivalent products. Product information was collected from four supermarket websites. Standard products were significantly cheaper, with more products available than GF (p < 0.05). GF bread products were significantly higher in fat and fiber (p < 0.05). All GF products were lower in protein than standard products (p < 0.01). Only 5% of GF breads were fortified with all four mandatory fortification nutrients (calcium, iron, niacin, and thiamin), 28% of GF breads were fortified with calcium and iron only. This lack of fortification may increase the risk of micronutrient deficiency in coeliac sufferers. It is recommended that fortification legislation is extended to include all GF products, in addition to increased regulation of the nutritional content of GF foods.
The objective of this study was to investigate the effects of annealing, succinylation, and a dual modification process (succinylation–annealing) on the physicochemical, thermal, and morphological properties of corn starch. Specifically, the properties of interest were the water-binding capacity (WBC), swelling power, paste clarity, solubility, pasting properties, stability ratio, and thermal and morphological characteristics. The dual modification process increased the physicochemical properties (WBC, swelling power, peak viscosity, and paste clarity) and increased the gelatinization temperature and gelatinization enthalpy (∆H), but had no effect on the morphological properties and X-ray diffraction patterns. A comparison of samples, made using each of the processes, showed that dual modification increased the stability ratio (more stable viscosity under thermal and shear stress), which was 0.69 for dual modified starch, compared with 0.64, 0.58 and 0.44 for native, succinylated, and annealed starches, respectively. The findings of the present study are of potential use in the food industry.
Non-celiac gluten sensitivity (NCGS), also referred to as non-celiac wheat sensitivity (NCWS), is a clinical syndrome characterized by both intestinal and extra-intestinal symptoms responsive to the withdrawal of gluten-containing food from the diet. The aim of this review is to summarize recent advances in research and provide a brief overview of the history of the condition for the benefit of professionals working in gastroenterology. Academic databases such as PubMed and Google Scholar were searched using key words such as ”non-celiac gluten sensitivity”, “gluten related disorders”, and the studies outlined in reference page were selected and analysed.
Most of the analysed studiers agree that NCGS would need to be diagnosed only after exclusion of celiac disease and wheat allergy, and that a reliable serological marker is not available presently. The mechanisms causing symptoms in NCGS after gluten ingestion are largely unknown, but recent advances have begun to offer novel insights. The estimated prevalence of NCGS, at present, varies between 0.6 and 6%. There is an overlap between irritable bowel syndrome and NCGS with regard to the similarity of gastrointestinal symptoms. The histologic characteristics of NCGS are still under investigation, ranging from normal histology to slight increase in the number of T lymphocytes in the superficial epithelium of villi. Positive response to gluten free diet for a limited period (e.g., 6 weeks), followed by the reappearance of symptoms after gluten challenge appears, at this moment, to be the best approach for confirming diagnosis. The Salerno expert criteria may help to diagnose NCGS accurately in particular for research purposes but it has limited applicability in clinical practice.
Introduction:
The cornerstone of the recommended treatment for Celiac disease (CeD) is a lifelong strict gluten-free diet (GFD). We aimed to identify prospectively the demographic, clinical, social and psychological profile associated with non-adherence to a GFD in adult CeD patients in Israel.
Methods:
An anonymous online questionnaire was sent via the Israeli Celiac association and through social networks. Only CeD patients≥18 years old were included. Socio-demographic, laboratory and clinical data as well as anxiety and depression scores were reported. Adherence to a GFD was assessed by a Biagi questionnaire.
Results:
In total, 301 patients completed the questionnaire with a mean age of 37.5±14.9 years, 79.2% female. The most common presenting symptoms were: anemia (59.7%), abdominal pain (50.8%) and diarrhea (42.8%). According to the Biagi score, 82% of patients were found to be high adherent to a GFD (Biagi 3-4) and 18% were low adherent to a GFD (Biagi-0-2). Univariate analysis revealed that low adherence was associated with: younger age at the time of diagnosis (P<0.001), longer duration of disease (P=0.011) non academic education (P=0.011), below average income (P=0.018), smoking (P<0.001) and no gastroenterology follow up (P=0.038). However, in multivariate analysis, only a young age at diagnosis and smoking were significantly associated with non-adherence to a GFD (OR 0.924, 3.48, P-value<0.001, 0.029, respectively). In further analysis, we identified that age 20 is the best cutoff value to discriminate between those with high adherence and those with low adherence.
Conclusions:
Young age, smoking, long disease duration, no academic education, low income and no gastroenterology follow-up were found to be associated with low adherence to GFD rate in a univariate analysis, however only the first two were found to be significant in the multivariate analysis. Additional intervention strategies might improve adherence and reduce future complications with a better quality of life.
The effect of energetic neutral nitrogen atoms (ENA) treatment at different plasma power (5W, 10W, 15W and 20W) for 10 min on the physico-chemical, mechanical, barrier and thermal properties of kithul starch films were studied. The surface of kithul starch film after ENA treatment showed higher roughness. Energetic neutral nitrogen atom treatment increased crystallinity. Tensile properties significantly (p≤0.05) increased after ENA treatment. Water vapour permeation (WVP), oxygen permeability, solubility and moisture absorption decreased in ENA treated kithul starch films. Higher opacity and lower WVP and oxygen permeability confirmed better barrier properties of ENA treated kithul starch films. Hence, treated kithul starch films with improved mechanical and barrier properties have a potential role in the area of biodegradable films.
Gluten- and additive-free rice bread is suitable for consumption by individuals who are sensitive to gluten and prefer to avoid additives. Here, we prepared 100% rice bread, which is a gluten-free rice bread prepared in the absence of additives, using 19 rice flour samples containing amylose contents ranging from 9.6 to 22.3%. The amylose content was positively correlated with the specific volume of the 100% rice bread, whereas no correlation was observed between the protein content and the specific volume. The amylose content was also positively correlated with the specific volume of gluten-free rice bread prepared following protease treatment of the dough. The dough of 100% rice bread prepared from rice flour containing higher amylose contents was better stabilized during leavening than that prepared from rice flour containing a lower amylose content. It was therefore apparent that amylose plays an important role in the preparation of 100% rice bread with a high loaf volume through stabilization of the dough.
This study aimed to valorise the underutilised by-product of proso millet decortication. Millet bran was sieved into three fractions with substantially different nutritional profile. The fraction with diameter <500 μm had the highest nutrient density (14% protein, 26% starch, 36% dietary fibre, 9% fat, and 3 mg GAE/g phenolics (d.w.)) and was analysed for oxidative stability, micronisation effect under cryogenic or ambient conditions (2, 4, 8, 12 min), and baking applicability. The bran was oxidatively stable under refrigerator conditions for 150 days. Micronisation slightly increased the antioxidant activity measured by FRAP and ABTS assays as well as the content of fibre soluble in water and 78% ethanol as the bran particle size decreased from 171 μm to 26–46 μm. Gluten-free bread containing 10% of the nutrient-dense fraction of millet bran had higher dietary fibre (76%) and phenolics content (117%), improved volume and crumb softness, regardless of the bran particle size (diameter of 50th percentile 171 vs. 26 μm).
Up to now, most of the research available to improve gluten-free (GF) bread is based on substituting or imitating the gluten network. Slightly less attention is given to technological approaches that modify batter properties such as consistency. This review summarizes the most recent advances to improve GF bread quality, focusing on latest conventional ingredients (e.g. hydrocolloids) and new innovative approaches to replace the gluten-network (i.e., use of enzymes, alternative polymer network), but especially on novel technological approaches, such as high hydrostatic pressure, sourdough technology and non-conventional heating methods. In general, hydrocolloids are still the most studied and well-known additives to gluten-free products, followed by the use of crosslinking enzymes. Within the review, special focus is given to the application of arabinoxylans, which form a stable carbohydrate network in GF batters that may substitute gluten. However, it was seen that technological approaches provide better solutions for enhancing GF bread properties than the latter, especially when non-conventional baking alternatives are applied. From these, ohmic heating resulted the most promising approach to overcome bread quality issues, while remaining time and energy-efficient.
Pseudocereals are gluten-free, nutrient-dense raw materials that are being considered for the production of gluten-free products, especially bread. This study proposes a gluten-free sourdough formula based on equal amounts of amaranth, buckwheat, and quinoa with a dough yield of 250, and an elaboration method to obtain ripe sourdough. Sourdough was characterized in terms of microbiology, pH, and total titratable acidity. The established protocol made it possible to obtain a spontaneous ripe sourdough with lactic acid bacteria populations of 9.60 ± 0.02 log CFU/g and total yeasts and non- Saccharomyces yeast populations (lysine positive) of 7.91 ± 0.15 and 7.52 ± 0.10 log CFU/g, respectively. Great pH stability and total titratable acidity were maintained in the ripe sourdough phase, with values of 4.04 ± 0.02 and 18.39 ± 0.56 ml NaOH 0.1 M/10 g, respectively, at the time of the next refreshment. The use of this sourdough could be an interesting alternative for the production of not only gluten-free bread but also other gluten-free products.
Application of biochars to remove inorganic nitrogen (NH4+, NO2-, NH3, NO, NO2, N2O) from wastewater and agricultural fields has gained a significant interest. This study aims to investigate the relationship between ammonium sorption and physicochemical properties of biochars derived from different kinds of fruit peel. Biochars from three species of fruit peel (orange, pineapple and pitaya) were prepared at 300, 400, 500 and 600 °C with the residence time of 2 h and 4 h. Their characteristics and sorption for ammonium was evaluated. The results show a clear effect of pyrolysis conditions on physicochemical properties of biochars, including elemental composition, functional groups and pH. The maximum NH4+ adsorption capacities were associated with biochars of orange peel (4.71 mg/g) and pineapple peel (5.60 mg/g) produced at 300 °C for 2 h. The maximum NH4+ adsorption capacity of the pitaya peel biochar produced at 400 °C for 2 h was 2.65 mg/g. For all feedstocks, biochars produced at low temperatures showed better NH4+ adsorption capacity. It was found that biochars had better adsorption efficiency on ammonium at a pH of 9. Adsorption kinetics of ammonium on biochars followed the pseudo-second-order kinetic model while Langmuir isotherm model could well simulate the adsorption behavior of ammonium on biochars. The adsorption mechanism of ammonium on biochars predominantly involved surface complexation, cation exchange and electrostatic attraction. Conclusively, the fruit peel-derived biochars can be used as an alternative to conventional sorbents in water treatment.
The impact of the addition of bee pollen (BP) (1, 2, 3, 4, and 5%) on the nutritional, bioactive and aroma composition of technologically viable gluten-free (GF) breads has been studied. The content of some macroconstituents (such as protein and lipids), minerals (K, Ca, Mg, Fe, Cu, Mn), and phytochemicals (carotenoids), the composition of biologically active compounds (soluble, insoluble and bioaccessible polyphenols), the antioxidant activity and the aroma profile of breads were investigated. The incorporation of BP into GF breads increased proteins, minerals, soluble and bioaccessible polyphenols, total carotenoids, and antiradical activity at almost all levels (2%–5%). Improvements in the phenolics composition of the resulting breads, as evidenced by a decrease in the insoluble/soluble polyphenols ratio (from 8.7 in the control to 4.2 in the breads with 4% and 5% of BP) and a concomitant increase in the polyphenol bioacessibility (36% rise in the bread with 5% of BP) in comparison to the control were also observed. BP did not affect the lipids content and the mineral composition, except for K and Ca. 48 volatile compounds were found in the examined breads, but only 5, namely pyrazinamide, 5-methyl-2-furaldehyde, 2-acetylfuran, furfural, 2-pentyl-furan, seemed to increase according to BP supplementation.
Gluten-free (GF) breads often lack proteins, minerals and fibres and have an imbalanced energy value, as they are primarily based on flour or starch. To nutritionally fortify GF bread, dietary fibres from milling and fruit processing by-products can be utilized. However, fibre addition changes sensorial, nutritional and also technological properties, such as dough or batter hydration. This review evaluates and compares different methods for quantifying the hydration properties of GF fibres and the resulting batters. Revelations are that the hydration properties of fibres vary greatly, depending on the utilized measuring technique, thus impeding the calculation of the appropriate water amount for GF batter processing. In addition, bran and fibres increase the loss factor tan δ and delay thermal transformation, compromising the specific loaf volume. Finally, operational strategies, such as enzymatic or extrusion treatments are discussed regarding their efficiency to increase water absorption in order to further improve GF bread quality.
This study investigated effects of mango peel powder on starch digestion properties and quality characteristics of bread, and discussed underneath mechanisms. Starch digestion rate and extent of bread were evaluated in vitro, and bread quality characteristics, including moisture content, volume, color and texture, were evaluated. The results showed that adding mango peel powder could significantly reduce starch digestion rate and digestion extent in bread, and the reduction degree was positively related to the amount of mango peel powder applied. Bread moisture content was improved by mango peel powder, while bread volume was reduced. Bread color was also impacted, showing increased L*, a* and b* values. And incorporation of mango peel powder apparently affected bread texture, resulting in increased hardness and chewiness, as well as decreased cohesiveness. These influences were generally proportional to the amount of mango peel powder applied. When <5% of mango peel powder was incorporated, bread quality was not dramatically changed, although starch digestibility was significantly inhibited. More mango peel powder could further reduce starch digestion; however, bread quality might be deteriorated. These results would provide guidelines for the development of low glycemic index foods, and be beneficial in facilitating comprehensive application of mango peel.
Background and objectives
Noodles from rice are consumed in most of the Asian countries due to ease in preparation and good consumer acceptability. So, the present study was designed to develop protein‐enriched noodles from rice flour and chickpea (germinated flour from 7% to 30% and protein isolate from 3% to 10%) and to investigate their physicochemical, cooking, rheology, electrophoretic properties, in vitro starch and protein digestibility and sensory evaluation.
Findings
The present study was carried out to access the effect of germinated flour (7%–30%) and protein isolate (3%–10%) from chickpea on rice‐based noodle qualities. Dynamic rheology of rice‐based noodle dough showed shear thinning behavior ( G ′ > G ″) with weak gel‐like characteristics. All the rheological models (Power law, Herschel–Bulkley, Bingham, and Casson) used were best fitted to experimental data with coefficient of regression ( R ² ) >93%. Results showed that with increase in level of the germinated chickpea flour and protein isolate, protein content (7.22%–14.35%), antioxidant activity (22.75%–33.79%), and total phenolic content (117.65–223.35 mg GAE/100 g) of the rice‐based noodles increased significantly ( p ≤ 0.05), whereas lightness, cooking time (13.35–10.13 min), cooking loss (7.38%–6.78%), cooked weight (41.40–33.15 g/100 g), percentage of starch gelatinization (65.36–41.26), and in vitro starch digestibility decreased significantly. The in vitro protein digestibility (78.68%–87.59%) of noodles increased significantly with added chickpea ingredients (germinated flour and protein isolate). The glycemic index (70.83 to 57.49) of the rice‐based noodles showed significant ( p ≤ 0.05) decrease with increase in level of chickpea ingredients (germinated flour and protein isolate). The chickpea‐enriched rice‐based noodle samples were characterized by a number of polypeptide with molecular weight from 250 to 10 kDa, with increased intensity of protein bands. Rice‐based noodles prepared with chickpea flour (20%) and protein isolate (8%) showed better overall acceptability on the basis of sensory evaluation.
Conclusions
Noodles prepared with germinated chickpea flour (20%) and chickpea protein isolate (8%) showed better acceptability on the basis of sensory score and recommended for noodle making with rice flour with improved noodle quality.
Significance and novelty
The research explored the possibility of germinated chickpea flour and protein isolate addition to rice for noodle formulation as functional food to target protein malnutrition, diabetes, and celiac diseases.
The study investigated the effect of sourdough made from combinations of four Lactobacillus spp. on the physicochemical properties, consumer acceptability, and shelf life of bread made from pearl millet flour. Fermentation based on both single and multiple species reduced the pH of the dough and increased its titratable acidity and H2O2 content. The addition of sourdough increased the elasticity and reduced the stiffness of the pearl millet dough. Sourdough fermented with L. brevis had the greatest effect on loaf height, specific volume, porosity, and moisture content. During storage, the moisture content of the bread crumb decreased, but that of their crust increased. Sourdough-based loaves retained their moisture better than conventional loaves and the sourdough suppressed the development of mold for a longer period. An organoleptic assessment showed that the sourdough-based bread was more palatable than either conventional or chemically acidified ones. The tissue softness, chewiness, and flavor of the pearl millet bread decreased during storage. The use of sourdough based on either L. brevis, L. paralimentarius, or L. brevis + L. paralimentarius is recommended to produce high-quality pearl millet-based bread.
Gluten elimination in bakery goods is a technological challenge since the absence of gluten generates breads with poor capacity to retain gas during leavening, which can be minimised with the use of gluten-free proteins in combination with hydrocolloids and/or enzymes. Due to the increasing world population and scarce land resources to expand current food production, it is necessary to find alternative and sustainable ways of growing food. This study aimed to characterise cricket (Gryllus assimilis) powder as a new protein source for gluten-free breads in comparison with the use of lentil and buckwheat flours. Cricket powder presented high water and oil holding capacities and appropriate microbiological features for human consumption. Results confirm that the enrichment with cricket powder can lead to the production of gluten-free bread with acceptable technological properties and high protein content. As the addition of cricket powder increases lipid contents, for better nutritional and functional results, the use of oil-free formulations is recommended.
Industrial relevance
Considering the rising world population and the scarce water and land resources, it is extremely important to find new and sustainable ways to produce food. Edible insects are particularly interesting due to its high protein content and lower environmental impacts compared to traditional livestock. This study evaluated the use of cricket powder as protein source for the production of gluten-free bread in comparison with two other protein sources: buckwheat and lentil flours. Results confirm that the enrichment with cricket powder can lead to the production of gluten free bread with acceptable technological properties and high protein content.
Maltogenic amylase (MAase) was encapsulated into maltodextrin (MD) with two dextrose equivalents (DEs). The encapsulated enzymes (EnEs) with different formulations have been used to make gluten-free breads. The EnE (encapsulated enzyme) into MD with a low value of DE (DE 1 4–7) (EnE-LMD), and the lowest MD (1%) and the highest (82 mg mL ⁻¹ ) concentrations yielded the highest encapsulation efficiency (EE) (93.35 ± 5.05%). A similar treatment, i.e., MD with a high value of DE (DE 2 16.5–19.5) (EnE- HMD) resulted in EE of 68.15 ± 18.07%, as the second high level of EE. The bread with EnE- LMD formulation had a higher quality (a lower weight loss, a higher uniformity of gas cells, and a better microstructure) in comparison with the breads with EnE- HMD and free enzyme (FE) formulations However, the breads with two formulations (EnE-LMD and EnE-HMD) had relatively the same firmness and moisture content. These two bread formulations were softer than that of the control, FE, and other formulations breads during storage.
Kithul (Caryota urense) starch was exposed to gamma irradiation at different doses (0.5 kGy, 1 kGy, 2.5 kGy, 5 kGy, 10 kGy). Its impact on physico-chemical, morphological, rheological properties and in vitro digestibility of kithul starch was studied. Irradiation decreased the pH, swelling index, amylose and moisture content of kithul starch and increased the carboxyl content, acidity, solubility. Free radical-mediated damage developed cracks and fissures on the granular surface of starch. Fourier transform infrared spectra (FT-IR) showed a marked reduction in the hydroxyl (OH) groups after irradiation. Irradiation did not affected to the crystalline pattern of native starch (Type-A pattern) but it decreased the relative crystallinity of kithul starch. Irradiation increased the light transmittance and freeze-thaw stability, but it reduced the syneresis. Pasting viscosity decreased after irradiation treatment. Irradiation made significant changes in the gelatinization properties of kithul starch. In vitro digestibility of kithul starch improved after irradiation and resistant starch followed decreasing trend. Lower value of storage modulus and loss modulus of irradiated kithul starches indicated to its weak gel formation.
Apple seeds are among the major natural sources of antioxidants and can be used in various industries. In this regard, antioxidant activity, total phenolic content, and individual phenolic compounds analyzes of defatted apple seed flours were firstly done in our study. According to these analyzes, total phenolic content, DPPH and ABTS radical scavenging activity of defatted seed flours were determined between 2861 and 5141 mg GAE/kg defatted seed, 21.45–43.56 μmol, and 291.50–391.79 μmol Trolox/g defatted seed, respectively. It was observed that the content of phloridzin represented 52–67% and 75–83% of the total phenolics that measured by the Folin-Ciocalteu assay and HPLC method, respectively. In the second part, chewing gums including defatted seeds were prepared and characterized in terms of phloridzin dissolution. The novel model described dissolution kinetics of phloridzin from chewing gum better than Higuchi and Korsmeyer-Peppas models. The results demonstrated that 5 min was enough for the dissolution of almost all phloridzin (88.43–96%) determined by centrifugation method and according to the model parameters, the chewing gum formulation can be optimized for providing controlled dissolution. In conclusion, chewing gum could be a suitable delivering material for phloridzin uptake, and apple seeds, a valuable agricultural by-product, could be evaluated in this way.
Cold pressing technology is a new technology using during the apple juice processing, which involved peeling and deseeding of apples at low temperature. The phenolics of apple juice, apple vinegar and apple pomace generated by cold pressing and traditional process were investigated. The results showed that the total phenols and flavanols of cold pressing apple juice were lower than those of traditional process. The total phenols content of peel pomace extract was significantly higher than that of the pulp pomace by almost tenfold, which showed that the peels and seeds were valuable sources of phenolic compounds. The total phenols of apple vinegars were significantly different. The predominant compounds in apple products were phloridzin and chlorogenic acid, while the apple pomaces based on cold pressing technology had significantly high content of phenolic compounds, indicating that the cold pressing technology could facilitated the use of apple pomace for bioactive compounds.
Background: Although formation of protein-protein crosslinks during food processing is known to influence food properties, a detailed molecular view of this crosslinking is still lacking. Even in the case of enzymatic crosslinking, such as with transglutaminase, which is commonly used in the food industry to induce crosslinking in food proteins, questions remain. Understanding the mechanisms of protein crosslinking is crucial to understanding how inherent beneficial characteristics of food can be preserved and enhanced, and therefore how quality, safety and function can be improved. Scope and approach: This work reviews recent developments in the study of crosslinking in food proteins. The advantages and limitations of varying proteomic techniques for evaluating protein-protein crosslinking in foods are discussed and areas of future study suggested. Key findings and conclusions: The advent of mass spectrometry-based approaches for identifying chemically induced crosslinks in proteins has introduced a welcome set of tools to elucidate protein structure. However, despite this progress, crosslinks that occur naturally in food or form during processing, continue to present unique challenges that have yet to be wholly overcome in studying complex food systems.
Background:
Previous systematic reviews and meta-analyses explaining the relationship between carbohydrate quality and health have usually examined a single marker and a limited number of clinical outcomes. We aimed to more precisely quantify the predictive potential of several markers, to determine which markers are most useful, and to establish an evidence base for quantitative recommendations for intakes of dietary fibre.
Methods:
We did a series of systematic reviews and meta-analyses of prospective studies published from database inception to April 30, 2017, and randomised controlled trials published from database inception to Feb 28, 2018, which reported on indicators of carbohydrate quality and non-communicable disease incidence, mortality, and risk factors. Studies were identified by searches in PubMed, Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials, and by hand searching of previous publications. We excluded prospective studies and trials reporting on participants with a chronic disease, and weight loss trials or trials involving supplements. Searches, data extraction, and bias assessment were duplicated independently. Robustness of pooled estimates from random-effects models was considered with sensitivity analyses, meta-regression, dose-response testing, and subgroup analyses. The GRADE approach was used to assess quality of evidence.
Findings:
Just under 135 million person-years of data from 185 prospective studies and 58 clinical trials with 4635 adult participants were included in the analyses. Observational data suggest a 15-30% decrease in all-cause and cardiovascular related mortality, and incidence of coronary heart disease, stroke incidence and mortality, type 2 diabetes, and colorectal cancer when comparing the highest dietary fibre consumers with the lowest consumers Clinical trials show significantly lower bodyweight, systolic blood pressure, and total cholesterol when comparing higher with lower intakes of dietary fibre. Risk reduction associated with a range of critical outcomes was greatest when daily intake of dietary fibre was between 25 g and 29 g. Dose-response curves suggested that higher intakes of dietary fibre could confer even greater benefit to protect against cardiovascular diseases, type 2 diabetes, and colorectal and breast cancer. Similar findings for whole grain intake were observed. Smaller or no risk reductions were found with the observational data when comparing the effects of diets characterised by low rather than higher glycaemic index or load. The certainty of evidence for relationships between carbohydrate quality and critical outcomes was graded as moderate for dietary fibre, low to moderate for whole grains, and low to very low for dietary glycaemic index and glycaemic load. Data relating to other dietary exposures are scarce.
Interpretation:
Findings from prospective studies and clinical trials associated with relatively high intakes of dietary fibre and whole grains were complementary, and striking dose-response evidence indicates that the relationships to several non-communicable diseases could be causal. Implementation of recommendations to increase dietary fibre intake and to replace refined grains with whole grains is expected to benefit human health. A major strength of the study was the ability to examine key indicators of carbohydrate quality in relation to a range of non-communicable disease outcomes from cohort studies and randomised trials in a single study. Our findings are limited to risk reduction in the population at large rather than those with chronic disease.
Funding:
Health Research Council of New Zealand, WHO, Riddet Centre of Research Excellence, Healthier Lives National Science Challenge, University of Otago, and the Otago Southland Diabetes Research Trust.
Background: Gluten-free (GF) bakery products available in the market are often poor in nutritional value, flavor, mouthfeel and have double the price as compared to traditional products. Strict GF diet has raised long-term concerns about food choices and dietary habits of celiac disease (CD) patients. Scope and approach: The limited intake of dietary fiber (DF) in GF diet along with other deficient nutrients is the main concern for the coeliacs, as the wheat flour is replaced with rice flour and commercially available starches, which results in lower DF intake. The population surveys indicated a lower intake of DF in coeliacs. The DFs from pseudo-cereals, GF cereals, fruits, vegetables, legumes and pulses are commonly used to complement the deficiency of GF products. Key findings and conclusions: Addition of DF significantly affects the color, firmness, moistness, crumb staling and microstructural feature of GF products. The coeliacs are advised to complement the DF intake from pseudo-cereals, fruits, legumes and pulses. This article covers the challenges faced by the food industry while complementing GF products with DF and the effect of DF on the techno-functional properties of the products with reference to GF products.
Large quantities of carrots are annually discarded in different parts of the world because they do not meet market standards. Besides the economic loss to the producers, the discard poses an environmental problem. In order to decrease the environmental impact produced by carrot discards and increase the sustainability of this important primary crop, an integral process of extraction of valuable by-products from discarded carrots (ethanol, carotene and a fiber rich fraction), is proposed in this work. Three processes that differ in the quality of the product obtained, the yields achieved, the equipment used and hence the costs involved are suggested. The selected procedure allows extracting 97% of fermentable sugars, which were used as feedstock for a fermentation reactor. The concentration of bioethanol obtained after fermentation process was 28.8 g L⁻¹. Bioethanol was subsequently used as a solvent for extraction of carotenes, thus reducing process costs. The extraction yield for carotenes was 94.2%. The composition of dietary fiber in the discards was also assessed. The soluble fiber (SDF)/insoluble fiber (IDF) ratio was 1:2.77, indicating that the fiber could be suitable for food supplementation.
Parboiling is a common method used in rice processing to improve milling yield and physicochemical properties. The current study evaluates parboiling as a pre-treatment step in millet decortication and its impact on phenolic profile and in vitro digestibility of two traditional millet products, steam-cooked couscous and porridge, made from pearl (Pennisetum glaucum) and proso (Panicum miliaceum) millets. Parboiling increased decorticated yield of pearl and proso millet by 37% and 28% respectively. It resulted in significant (P < 0.05) rise in free and bound phenolic contents and DPPH (2,2-diphenyl-1- picrylhydrazyl) radical scavenging activity of the millet products. This method significantly (P < 0.05) changed starch digestion fractions of both products thereby reducing expected glycemic index (eGI) while the in vitro protein digestibility of products decreased by 14–17%. Parboiling could be an effective way to improve millet decortication yield as well as produce millet products with higher phenolic acids antioxidant activity and lower GI.
Fatty acid, tocopherol, and amygdalin concentrations are determined in apricot kernel oils obtained by two techniques: cold pressing and supercritical CO2 (SC‐CO2) extraction. During the SC‐CO2 extraction, oil is collected over 5 h at 300 bar and 40 °C until all oil is completely extracted from the raw material. The total tocopherol concentration in cold pressed oil is significantly lower (94 mg 100 g⁻¹ of oil) compared to SC‐CO2 oil. β + γ‐tocopherols are the most dominant, while α‐tocopherol is not detected in cold pressed oil. The concentration of total tocopherols during SC‐CO2 extraction decreases from the first collection (after 1 h) to the last (after 5 h), from 252 to 50 mg 100 g⁻¹ of oil. The analysis of fatty acid composition shows a prevalence of palmitic, oleic, and linoleic acid, specifically 5.93, 57.33, and 33.81%, respectively, in SC‐CO2 extracts, which are similar to the values of cold pressed oil (5.48, 62.73, 29.18%, respectively). Small amount of amygdalin content is determined in cold pressed oil (0.40 mg g⁻¹ of oil), as well as in oil obtained by SC‐CO2 (0.20 mg g⁻¹ of oil). According to official methods and requirements, oils produced by both techniques are of satisfactory quality (low values of peroxide number, FFA, insoluble impurities, and moisture content).
Practical Applications: This study investigates the potential of apricot kernel seeds, a by‐product of apricot production, for an important food industry application: the extraction of quality oil with a high concentration of various bioactive compounds using green technologies – cold pressing and SC‐CO2. Comparison of these two extraction methods shows the advantage of a newer method (SC‐CO2) in the extraction of tocopherols as well as less extracted amount of amygdalin, while there are no major differences in the fatty acid composition. Therefore, it can be concluded that apricot kernel seeds can be used, by employing such green extraction technologies, for the production of oils with a high concentration of valuable bioactive compounds, especially fatty acids and tocopherols.
Components and fatty acids collected by two different green extraction techniques of apricot kernel seed.
An overview of wine making by-products and their conventional and non-conventional uses, Valorization of Wine Making By-Products gives you a deeper understanding of recovery processes that are a part of the new philosophy of sustainable agriculture. In line with the worldwide movement toward sustainable development, this book examines how to convert waste into useful products and to recycle waste products. It provides the research underpinning the processes and highlights new value-adding valorization technologies. Although vine cultivation and vinification generate a significant amount of waste and several by-products, generally only a very small portion of these materials are used. The book gives you a detailed overview of the typology of different by-products and describes several technological aspects of by-product utilization. It details regulatory, legislative, and sustainability issues before exploring marketing potential and future perspectives. The book highlights wine by-products as potential sources of bioactive phytochemicals, which could be used for various purposes in the pharmaceutical, cosmetic, and food industries. Efficient utilization of food processing by-products represents challenges for the profitability of the food industry. In addition, during the next few years, the area of food processing waste management, where wine industry plays a leading role, will expand rapidly. This has resulted in the need for a detailed book on valorization of wine making by-products. In response, this book provides you with a number of value-adding technologies for the valorization of those products.
Foxtail millet starch was modified by annealing (AS), ultra-sonication (US) and a combination of the two treatments (annealing and ultra-sonication (AUS) or ultra-sonication and annealing (UAS)) and they were characterized. Compared to the native starch (NS), modified starches particularly UAS contained the highest amylose (27.96%). Ultra-sonication prior to annealing had a predominant effect on resistant starch (RS) level (UAS-45.59%). Among the modified starches, UAS had exhibited superior resistance to acidic (0.94) and shear (0.68) stability. Sonication, when used as the second treatment (AUS) elevated the final viscosity compared to its counter ones possibly due to the effects of cavitation promoted by sonication treatment. UAS had showed an A-type diffraction pattern and dominant peaks in FT-IR spectra. It can be inferred that dual modification of starch by ultra-sonication followed by annealing had exhibited the most desirable properties such as high acid and shear resistance, high freeze-thaw stability and improved gel texture.
The altered morphology, amylose content, microstructure, viscosity and thermal properties of potato starch after heating by radio frequency (RF) and microwaves (MW) were studied and contrasted with the native potato starch. The results showed that the MW treatment roughens the starch surface and lowers the amylose content of the starch, even more than the RF-treated starch does. The starch granule size of MW treated was larger than RF treated. RF treatment altered the structure and reduced the crystallinity of the starch, but the MW treatment did not affect the crystal form. The gelatinization temperature of the MW-treated starch was higher than the native potato starch, while the RF-treated starch was lower than the native starch. The results also indicated that the peak viscosity and the breakdown viscosity values of the RF-treated starch consistently surpassed that of the MW-treated starch. The results exposed the facts that RF treated starch showed the same trend on crystal and pasting properties compared with the hot water annealing starches, which suggested RF can be an efficient method for starch annealing.