Oliver Schlüter

• Dr.-Ing. habil.
• Senior Scientist and Vice-head of Department at Leibniz Institute for Agricultural Engineering and Bioeconomy

Recent studies have suggested that fresh aquaculture waste (ASW) could be satisfactorily treated with black soldier fly larvae (BSFL). However, pre-treatments such as drying or dewatering, which significantly modified the chemical, physical and microbiological properties of the waste, were always applied. On the other hand, industrially generated a...

Integrated biorefineries play a transformative role in sustainable development by converting biomass and biogenic residues into high-value products while minimizing waste, emissions, and resource inefficiencies. This review explores innovations in biorefinery processes, emphasizing the synergy between thermochemical, biochemical, and biological tec...

The increasing interest in edible insects, driven by projected global population growth and environmental concerns, has led to the exploration of their potential in the food sector. Edible insects are abundant in macronutrients, such as proteins, lipids and chitin, as well as micronutrients, such as minerals, vitamins and phenolic compounds. Consid...

The olive leaf is one of the main by-products from the olive oil industry. This by-product is a rich source of phenolic compounds that have been shown to possess beneficial health activities, which are due in part to their antioxidant activities. Therefore, the revaluation of this by-product would be of great importance for the food industry. For t...

Edible insects are an important source of chitin and chitosan. Different methods, including the use of proteases, fermentation and microwave treatment, have been proposed to replace the conventional chitin isolation methods. House crickets are among the most commonly used insects for food applications. Chitosan was produced from house crickets from...

House crickets are among the most promising edible insect species for inclusion in future agri-food systems. Their appeal stems from environmentally sustainable rearing practices, a high nutritional value, and a long history of traditional use as food. Additionally, their rearing produces a byproduct known as frass, which holds potential as a valua...

Promalin (Valent BioSciences, Libertyville, IL, USA) is a proprietary mixture of gibberellin A 4 + 7 and 6-benzyladenine that is widely used in apple production to improve the fruit shape, size, and skin quality. Promalin typically increases fruit size and length. However, the increased growth likely increases the strain in the fruit skin, which ma...

The main objective of this work was to evaluate the combined effect of a biotechnology process, based on selected yeast strains, and a high-pressure homogenization (HPH) treatment on the microbiological quality, structural organization of proteins, chitin content, and antioxidant activity of a mixture of cricket powder (Acheta domesticus) and water...

Aquaculture solid waste (ASW) is a nutrient rich material that can pose a significant environment challenge if not properly managed. This study investigated the potential of black soldier fly (BSF) larvae in converting this waste into biomass. Five substrates comprising chicken feed supplemented with varying proportions of fresh ASW (0%, 25%, 50%,...

Fresh insects in the form of paste can be conveniently utilised for further food preparations and processing at both household and industrial levels. However, due to the high moisture content and particular physiochemical properties, insect paste is highly unstable and susceptible to significant quality changes during storage. The aim of this study...

Introduction Edible insects, specifically house crickets, are expected to play an important role in the future food systems due to their rich nutritional profile, low environmental impact and growing consumer acceptance as food. Their content of proteins, lipids, chitin and phenolics offer great potential for the valorization of their biomass into...

In order to address human zinc deficiency, fortifying staple foods with zinc is a safe and cost-effective solution. To ensure the nutritional properties and quality of a final product, zinc tolerance of the microorganisms involved in the fermentation is necessary. Bread, which is widely consumed, occupies a substantial place in many people’s diets,...

Preserving fruits and vegetables by drying is a traditional yet effective way of reducing food waste. Existing drying methods are either energy-intensive or lead to a significant reduction in product quality. Electrohydrodynamic (EHD) drying is an energy-efficient low-temperature drying method that presents an opportunity to comply with the current...

Globalization and rapid urbanization have led to tremendous improvement in the agriculture and food processing sectors to fulfil the food demands. In this context, managing food product safety and quality throughout the agri-food chain (pre-harvest to post-harvest) becomes vital to avoid food spoilage and increase production. Numerous innovative in...

Cold plasma technologies are considered environmentally friendly and sustainable due to low temperature operation without much energy usage, shorter processing time and limited usage of water and other solvents in the treatment. With these, plasma processing has shown huge potential in many industrial and technological sectors. The chapter presents...

Facing an inexorable growth of the human population along with substantial environmental changes, the assurance of food security is a major challenge of the present century. To ensure responsible food consumption and production (SDG 12), new approaches in the food system are required. Thus, environmentally controlled, sustainable production of alte...

Indoor co-cultivation systems can answer to the need for sustainable and resilient food production systems. Rearing organisms under light-emitting diodes (LEDs) irradiation provides the possibility to control and shape the emitted light spectra. UV-B-irradiation (280–315 nm) can positively affect the nutritional composition of different plants and...

Alternative methods were evaluated for chitin isolation from Acheta domesticus. Chemical demineralization was compared to fermentation with Lactococcus lactis, citric acid treatment, and microwave treatment, leading to a degree of demineralization of 91.1 ± 0.3, 97.3 ± 0.8, 70.5 ± 3.5, and 85.8 ± 1.3%, respectively. Fermentation with Bacillus subti...

The purpose of this research was to evaluate the potential of a sourdough containing cricket powder hydrolysate by the RO25 Yarrowia lipolytica strain to produce an innovative bakery product. RO25 hydrolysed cricket bread (RO25H-CB) was compared with control bread obtained from a traditional sourdough using wheat flour and with an additional bread...

Ultrasound is a versatile technology and has been successfully applied in several food processes including extraction, drying, decontamination, brining, mixing and homogenization, emulsification, freezing, thawing, and cutting of foods. High-power ultrasound can induce physical and chemical changes in the biological matrices due to mechanical, cavi...

A wide variety of novel non-thermal processing technologies (NTPTs) are under development to meet the increasing consumer demand for high-quality fruit and vegetable (F&V) products. Understanding consumers’ needs and possible barriers to acceptance of these technologies is however essential to assess the commercial feasibility of mildly processed F...

Ultrasound is a well-known technology to develop various effective, efficient, and reliable processing applications in the food industry. Ultrasound is a versatile technology and has been applied efficiently in food processes including extraction, drying, decontamination, mixing and homogenization, emulsification, freezing, thawing, and cutting of...

As microbial contamination is persistent within the food and bioindustries and foodborne infections are still a significant cause of death, the detection, monitoring, and characterization of pathogens and spoilage microorganisms are of great importance. However, the current methods do not meet all relevant criteria. They either show (i) inadequate...

Herbal teas can cause diseases, when their naturally high microbial load is not inactivated via proper brewing. Cold plasma as effective and gentle decontamination technique was investigated for dried peppermint, stinging nettle, and lemongrass. Microwave-driven plasma processed air (up to 7.5 min) significantly reduced total viable counts up to 1....

Edible insects are an important source of proteins, fat, and chitin, which need to be extracted to develop tailored products with a controlled composition. Pulsed electric fields (PEF) is a non-thermal technology that can enhance the extraction. This study explores the effect of PEF on the extraction of protein, fat and chitin from cricket flour, a...

Fluorescence spectroscopy coupled with chemometric tools is a powerful analytical method, largely used for rapid food quality and safety evaluations. However, its potential has not yet been explored in the novel food sector. In the present study, excitation emission matrices (EEMs) of 15 insect powders produced by milling insects belonging to 5 Ort...

The pattern of cuticle deposition plays an important role in managing strain buildup in fruit cuticles. Cuticular strain is the primary trigger for numerous fruit-surface disorders in many fruit crop species. Recent evidence indicates a strain gradient may exist within the apple fruit cuticle. The outer layers of the cuticle are more strained and t...

Sprouts are particularly prone to microbial contamination due to their high nutrient content and the warm temperatures and humid conditions needed for their production. Therefore, disinfection is a crucial step in food processing as a means of preventing the transmission of bacterial, parasitic and viral pathogens. In this study, a dielectric copla...

Globally, the expansion of livestock and fisheries production is severely constrained due to the increasing costs and ecological footprint of feed constituents. The utilization of black soldier fly (BSF) as an alternative protein ingredient to fishmeal and soybean in animal feed has been widely documented. The black soldier fly larvae (BSFL) used a...

The processing of insects is paramount to deliver safe and high quality raw materials, ingredients and products for large-scale food and feed applications. Depending upon the nature of the initial material and the desired end product, the processing pathways vary and may include several unit operations currently already used in food and feed proces...

Edible insects are high value alternative protein sources, exhibiting high quality nutrient compositions along with potentially health-promoting constituents. Insects are rich in protein (35-61 %), lipids (13-33 %) and also contain a significant amount of ‘animal’ fiber in form of insoluble chitin. Apart from macronutrients, some insects are also k...

Red currants, berries usually consumed fresh, are prone to fast quality deterioration, due to microbial spoilage. This study evaluates diffuse coplanar surface barrier discharge cold atmospheric pressure plasma (DCSBD CAPP) treatment as a potential decontamination technique for red currants and investigates its effects on microbial load and quality...

Sustainable and microbiologically secure foodstuff production lines are of increasing scientific interest and are in the focus of recent research programs. Additionally, they are of great importance for the production industry due to the prevention of food-borne illnesses caused by pathogens such as Salmonella sp., Listeria monocytogenes, or Escher...

The last two decades saw a steady increase of high hydrostatic pressure (HHP) used for treatment of foods. Although the science of biomaterials exposed to high pressure started more than a century ago, there still seem to be a number of unanswered questions regarding safety of foods processed using HHP. This review gives an overview on historical d...

Simple Summary The main nutritionally relevant proteins of Tenebrio molitor L. larvae are cereal proteins. Cereals contain α-amylase/trypsin inhibitors (ATIs) that interact with digestive enzymes and which may impair the growth of the larvae. Despite the existing work on the subject, there is still a lack of information regarding the effects of ATI...

The principal aim of this research was to use Yarrowia lipolytica RO25 to obtain a cricket powder-based hydrolysate to produce sourdough for bread production. RO25 hydrolysed cricket sourdough (RO25H-CS) was compared with a control traditional sourdough and a control containing the no-hydrolysed cricket powder. Microbiological analyses evidenced a...

The objective of this work was to investigate the potential effect of cereal α-amylase/trypsin inhibitors (ATIs) on growth parameters and selective digestive enzymes of Tenebrio molitor L. larvae. The approach consisted of feeding the larvae with wheat, sorghum and rice meals containing different levels and composition of α-amylase/trypsin inhibito...

The effect of cold atmospheric pressure plasma (CAPP) on three strains of Staphylococcus aureus and one strain of Listeria monocytogenes on gel discs was studied. A plasma jet operating in argon was used and exposure times were from 5 to 120 s. Bacteria had been isolated from dairy environments. In comparison, peracetic acid (PAA, 0.5% v/v) applied...

Sprouts are particularly prone to microbial contamination due to their high nutrient content and the warm temperatures and humid conditions needed for their production. Therefore, disinfection is a crucial step in food processing as a means of preventing the transmission of bacterial, parasitic and viral pathogens. In this study, a dielectric copla...

Combination processes involve combining two or more techniques into a single process to reduce the severity of a thermal method on nutrients or to reduce the cost of production by using nonthermal methods or to improve the capability of a process. This technical concept is becoming significant as it uses only a minimal dosage of thermal process par...

Hepatitis E virus (HEV) is the causative agent of acute and chronic hepatitis in humans. The zoonotic HEV genotype 3 is the main genotype in Europe. The foodborne transmission via consumption of meat and meat products prepared from infected pigs or wild boars is considered the major transmission route of this genotype. High hydrostatic pressure pro...

Food loss and waste are serious threats to the sustainability of our food systems. Innovative and multi-faced solutions are continuously being proposed, tested and implemented by researchers, government authorities, non-government bodies and food industries to tackle this problem of food waste. Insect-based bioconversions have been reported as a ma...

The aim of this study was to determine the effect of blanching followed by fermentation of mealworms (Tenebrio molitor) with commercial meat starter cultures on the functional properties of powders produced from the larvae. Full fat and defatted powder samples were prepared from non-fermented and fermented mealworm pastes. Then the crude protein, c...

Many global health risks are related to what and how much we eat. At the same time, the production of food, especially from animal origin, contributes to environmental change at a scale that threatens boundaries of a safe operating space for humanity. Here we outline viable solutions how to reconcile healthy protein consumption and sustainable prot...

Cold plasma is considered to be a novel, non-thermal, chemical-free and eco-friendly disinfection and surface modification technology. Plasma treatment of air to generate the so called plasma processed air (PPA) induces the formation of reactive oxygen (ROS) and nitrogen species (RNS). As a result, PPA has a different chemical composition compared...

The current study aimed at investigating the impact of nitrogen (N)‐generated cold atmospheric pressure plasma (CAPP) treatment on blueberries focusing on the overall impact on berry quality and microbial load along a storage period of 10 days. Blueberries were treated for 0 (control), 5, and 10 min. Assessment of fruit quality (°Bx, ascorbic acid,...

The role of insects for human consumption has lately increased in interest and in order to deliver safe and high-quality raw materials and ingredients for food and feed applications, processing of insects is a major pre-requisite. For edible insects a thermal treatment and appropriate storage conditions are recommended to minimize the microbiologic...

The aim of this study was to determine the effect of fermentation of mealworms (Tenebrio molitor) with commercial meat starters cultures on the functional properties of powders produced from the larvae. Full fat and defatted powder samples were prepared from non-fermented and fermented mealworm pastes. Then the crude protein, crude fat and dry matt...

High hydrostatic pressure (HHP) treatments affect the integrity and function of biomembranes and proteins of fresh produces. Initially, pressure affects membrane permeability, directly linked to a reversible decline in cell turgor. Reversibility reflects the restoration of intracellular solute gradients by re-established membrane semi-permeability...

Cold plasma (CP) technology has shown huge potential at different stages of the food production and processing chain for a range of applications including fertilization, improved germination, food functionalization, microbial decontamination and toxin degradation. This article presents an overview on plasma sources and delivery systems. Current app...

This research was aimed at producing, by the use of Yarrowia lipolytica and Debaryomyces hansenii strains, cricket powder hydrolysates endowed with high food safety, functionality, sensory and technological properties to be further used as food ingredients. The hydrolysates were characterised, in comparison to a control, by a reduced chitin content...

Foodborne illness outbreaks around the world have been associated with frozen and fresh berries. Therefore, given the increasing consumption of berries over the last decades, it is important to investigate technologies that can eliminate pathogens responsible for such outbreaks. Cold atmospheric pressure plasma (CAPP) has been shown to have a great...

Editorial Notes for Special Issue on Cold Plasma Technologies

The impacts of high hydrostatic pressure (HHP) treatments on metabolic functionality and quality of fruit and vegetables are still poorly understood. The effects of pressure intensity (100, 150 and 200 MPa) and holding time (5 and 10 min), and temperatures (20, 30 and 40 °C) during HHP treatment on fresh radish tubers has been studied. Colour, stif...

As spoilage microorganisms on food contact surfaces can cause cross-contaminations, their proper cleaning and disinfection is of great importance. Food industry requirements and increasing environmental concerns require methods with mild processing conditions and reduced energy consumption. Plasma techniques including plasma treated or activated wa...

The food industry deals with a variety of raw materials, ingredients, intermediates and processed products, each with its characteristic techno-functional properties. However, in food processing it is occasionally desirable or necessary to modify these specific properties in a targeted manner. Quite a number of industrial branches is already benefi...

The viable but non-culturable (VBNC) state, as well as sublethal injury of microorganisms pose a distinct threat to food safety, as the use of traditional, culture-based microbiological analyses might lead to an underestimation or a misinterpretation of the product’s microbial status and recovery phenomena of microorganisms may occur. For thermal t...

Ochratoxin A (OTA) is one of the most abundant food-contaminating mycotoxins. Besides their high toxicity, mycotoxins are highly stable to physical, chemical or biological detoxification. Therefore, the treatment with cold atmospheric plasma could be one approach to reduce the amount of mycotoxins in different products. The aim of this study was to...

Essential oils (EOs) or their components represent one of the most promising natural, safe, and feasible alternatives to prevent the growth of food-borne pathogens like Listeria monocytogenes and Escherichia coli in food matrices. Although antimicrobial properties of EOs and their components are well-documented, limited and fragmented information i...

Cold plasma is described as a promising technique for the treatment of fresh food. In particular, the application of plasma-treated water gained interest in fresh-cut produce processing. This study aimed to evaluate the effectiveness of plasma-treated water (PTW) to decontaminate lettuce during washing on a pilot-scale level with special interest i...

In this study, the composition of the microbial community on endive lettuce (Cichorium endivia) was evaluated during different postharvest processing steps. Microbial community structure was characterized by culture-dependent and culture-independent methods. Endive lettuce was sampled exemplarily at four different stages of processing (raw material...

Owing to an increasing world population and a rising demand in protein for food and feed, alternative protein sources are needed. In addition, existing food and protein supplies such as wild and farmed fish need to be secured. Insects and more specifically the black soldier fly (BSF; Hermetia illucens) larvae, are discussed as an alternative animal...

The post-mortem accumulation of the heme biosynthesis metabolite zinc protoporphyrin IX (ZnPP) in porcine muscle is associated with both a meat-inherent and a bacterial enzymatic reaction during meat storage. To estimate the bacterial impact on ZnPP formation, meat and meat-like media were investigated by HPLC-FLD (and MALDI-TOF-MS) after inoculati...

The decontamination and sanitation methods currently used are mainly antimicrobial ineffective, generate high costs with a high consumption of water and chemicals (additives). As an alternative, non-thermal plasma at atmospheric pressure could be a versatile tool. Therefore, a pilot-scaled set-up based on a microwave-plasma source that generates pl...

http://www.asg-goe.de/pdf/LR0317.pdf ISSN 0179-7603

In this study factors involved in spore resistance to cold atmospheric pressure plasma (CAPP) were investigated. Therefore, wild-type Bacillus subtilis spores and isogenic mutant strains, PS578 lacking the genes encoding the spore's two major small acid soluble proteins (SASPs), FB122 being unable to synthesize dipicolinic acid (DPA) during sporula...

The increasing demands of society for healthy nutrition in combination with continuously decreasing willingness to spend time for food preparation leads to a rising consumer demand for minimal processed ready-to-eat (RTE) products (convenient food). The USA is the leading nation in the consumption and therefore, the biggest market for these kinds o...

Due to the growing world population and changing eating habits, there is an increasing demand in sustainable alternative protein sources, whereas the available land for the production of plant and animal protein decreases owing to desertification and urbanization. Furthermore, the rapidly decreasing resources of fossil fuels necessitate more sustai...

Investigations on the post mortal formation of fluorescent zinc protoporphyrin (ZnPP) IX in pork meat are currently in focus of meat science research. The role of myoglobin degradation in this context appears to be one of the most diversly discussed issues. To address this question meat-extracts of longissimus lumborum (LL) muscle (0.8 mg/mL) were...