1,720,964 research outputs found
Bioassays for the optimization of Hermetia illucens (L.) egg laying in a prototype of industrial plant
No full textThe black soldier fly Hermetia illucens (L.) (Diptera: Stratiomyidae) presents a particular interest for the feed and food industry as its larvae have the capacity to convert quickly and efficiently large quantities of organic waste or byproducts into a protein biomass rich in fats. Although the information on larvae development is abundant, the necessary knowledge of adult biology to produce large amounts of eggs remains a great challenge.
This work represents a part of a regional project (ValoriBio, Emilia Romagna, Italy) where one of the main outputs is the construction of a pilot plant for H. illucens mass rearing, which includes a module for adult rearing. Therefore, a specific custom-made climatic chamber was developed and it consisted in a thermally insulated container (1m3 volume), with a transparent window bearing a light-emitting diode (LED) lights source (UV, green and blue LEDs) on top. Temperature and humidity were controlled through a Peltier cooler/heater system, an ultrasound humidifier and several humidity-temperature digital sensors. An exterior electronic board connected to a touch screen was developed to control and record the rearing parameters. The biological parameters used to establish the functionality of the prototype were the patterns of oviposition, the egg weight and adult longevity.
Bioassays were conducted in tree types of climatic chambers at 27°C ± 0,5°C and 70 ± 5% relative humidity considering as treatments the use of different light sources (fluorescent tubes, white LEDs and the UV-green-blue combination of LEDs) and the flies diet (water and sugar, just water or nothing). The results allowed to identify the better conditions to obtain the highest amounts of eggs in the shortest time
Influence of Processing Parameters and Natural Antimicrobial on Alicyclobacillus acidoterrestris and Clostridium pasteurianum Using Response Surface Methodology
Full text linkThe food industry must ensure the stability of the products, and this is often achieved by exposing foods to heat treatments that are able to ensure the absence of pathogenic or spoilage microorganisms. These treatments are different in terms of temperature and duration and could lead to a loss in nutritional and sensory value. Moreover, some types of microorganisms manage to survive these treatments thanks to the sporification process. The addition of antimicrobials can become necessary, but at present, consumers are more inclined toward natural products, avoiding synthetic and chemical additives. Antimicrobials from plants could be a valuable option and, in this context, a patent concerning an antimicrobial extract from fermented plant substrate was recently tested against foodborne pathogens revealing high antimicrobial activity. The objective of this study was the creation of a model for the evaluation and subsequent prediction of the combined effect of different process and product variables, including antimicrobial addition, on the inhibition and reduction of spore germination of target microorganisms, Alicyclobacillus acidoterrestris and Clostridium pasteurianum, responsible for spoilage of tomato-based products
Exploitation of Impedometric Analysis and Fluorescence Microscopy: Assessment of Alicyclobacillus acidoterrestris Life Cycle and Innovative Inactivation Strategy
No full textEvaluation of biological parameters and the lipid profile of black soldier fly (Hermetia illucens, Stratiomyidae) reared on byproducts from different food chains
No full textThe total amount of bio-waste produced annually in the EU by the food and beverage value chains is estimated at 37 Mtons. The possibility to use insects for the valorization of byproducts from these chains may represent a sustainable and valuable solution. This study aimed to analize the development parameters and the lipid content of black soldier fly (Hermetia illucens, Stratiomyidae) prepupae reared on byproducts obtained from different food chains.
The substrates used for this experiment were: beer brewery byproducts, tomato skins and seeds, spent ground coffee, grape stalks and marcs, bread dough, cow milk whey and fish-waste material.
H. illucens larvae were reared on each substrate within glass containers at 28 ± 0.5 °C and 98% relative humidity. Biological parameters such as larval weight, prepupae weight and development time were recorded. Obtained prepupae were frozen before fractionation and chemical characterization. Lipid extraction was carried out using the Folch method, adjusted for the specific samples. The total lipid content was calculated and the quantitative characterization of the fatty acid profile was performed through GC-FID analysis.
The best larval performance was obtained when specimens were reared on byproducts from beer, tomato and cheese food chains. The different substrate composition was reflected in the lipid profile of H. illucens larvae. In particular, the saturated to unsaturated fatty acid ratio showed marked changes according to the substrate. The high content and type of lipids, together with the proteins and chitin extracted from the prepupae represent high-value biobased products that might be used in the feed/food industry as well as for the development of innovative biomaterials for different technological purposes.
These results suggest that mass rearing of H. illucens larvae, especially on some of the tested byproducts, may be exploited for an alternative employment of the food/beverage bio-waste
Dynamic changes in molecular composition of black soldier fly prepupae and derived biomasses with microbial fermentation
No full textBlack soldier fly (BSF) is being increasingly used for agro-food by-products valorisation. Adult flies, puparia, and excess of prepupae are the by-products of this process, which could be further valorised. Lactic fermentation of BSF biomasses with two different strains (L. rhamnosus and L. plantarum) has been used for this purpose. Deep changes in the molecular composition were observed, without significant differences related to the different strains used. The lipid and protein fractions were the most impacted. Fermentation enriched the biomass in monounsaturated and polyunsaturated fatty acids and essential amino acids, significantly improving the nutritional properties of the substrates. Although not particularly marked, a proteolytic activity of lactobacilli was observed on the BSF muscular and cuticular proteins, especially in the samples of adult flies and puparia, where fermentation resulted more effective. Conversely, there was no evidence of chitinolytic activity
A critical review of intrinsic and extrinsic antimicrobial properties of insects
No full textBackground: Sustainable nutrition and food security are central topics in the current global agenda. Insect production represents a promising food source that has received growing attention in the food and feed industry due to its high nutritional value and positive effect on animal health. The resilience of insects to infections by different parasites indicates they are an excellent type of biomass for the extraction of various antimicrobial compounds. Scope and approach: The antimicrobial potential of insects is illustrated through a description of the different sources of antimicrobial compounds. Distinctions between intrinsic and extrinsic insect antimicrobials are presented in terms of their constituent components and metabolites produced. An updated overview of potential applications in food and feed sectors is presented to identify key reasons to invest in this food source and to stimulate further research in this field. The main aspects supporting the development of this industry in the future are summarized. Key findings and conclusions: Processing extracted insect fractions will lead to the development of new application possibilities and an increase in the edible insect sector value. The possibility of producing new generation antimicrobials from a sustainable supply chain involving insect rearing contributes to green economy policies and reduction of antibiotic resistance
Lactic Acid Fermentation of Chlorella vulgaris to Improve the Aroma of New Microalgae-Based Foods: Impact of Composition and Bacterial Growth on the Volatile Fraction
No full text: The consumption of microalgae-based foods is growing due to their exceptional nutritional benefits and sustainable cultivation. However, their strong off-flavors and odors hinder their incorporation into food products. Lactic acid fermentation, a traditional method known for modifying bioactive and aromatic compounds, may address these challenges. This study aims to evaluate the impact of lactic acid fermentation on the aromatic profiles of four distinct Chlorella vulgaris biomasses, each varying in protein, carbohydrate, lipid, and pigment content. Six lactic acid bacteria (LAB) strains, Lacticaseibacillus casei, Lcb. paracasei, Lcb. rhamnosus, Lactiplantibacillus plantarum, Lactobacillus delbrueckii subsp. bulgaricus, and Leuconostoc citreum, were used for fermentation. All biomasses supported LAB growth, and their volatile profiles were analyzed via HS-SPME-GC-MS, revealing significant variability. Fermentation notably reduced concentrations of compounds responsible for off-flavors, such as aldehydes. Specifically, hexanal, associated with a green and leafy aroma, was significantly decreased. Lcb. paracasei UPCCO 2333 showed the most effective modulation of the volatile profile in Chlorella vulgaris, significantly reducing undesirable compounds, such as aldehydes, ketones, pyrazines, and terpenes, while enhancing ester production. These results highlight lactic acid fermentation as an effective method to improve the sensory characteristics of C. vulgaris biomasses, enabling their broader use in innovative, nutritionally rich food products
Lipid profile and growth of black soldier flies (Hermetia illucens, Stratiomyidae) reared on by-products from different food chains
No full textBACKGROUND: The total amount of bio-waste produced annually in the EU by the food and beverage chains is estimated at 37 billion kg. The use of insects for the valorization of by-products from these value chains may represent a sustainable solution. This study aimed to investigate the by-products obtained from different food chains and used for the rearing of black soldier fly (BSF) prepupae, and to evaluate the content and profile of the lipid extracted from the prepupae and outline its possible applications. The substrates used in this experiment were: (i) industrial by-products (brewery spent grains, cows’ milk whey, grape stalks, and tomato peels and seeds) and (ii) by-products from retailers (bread dough, fish scraps, and spent coffee ground). Fat extracted from prepupae using an adjusted Folch method was used for total lipid content and fatty acid profile. RESULTS: The best larval performances were obtained from beer (0.22 gweight per prepupa), tomato (0.19 gweight per prepupa), and cheese (0.14 gweight per prepupa) food-chain by-products. The extremely different compositions of the substrates were reflected in the differentiated lipid profile of the BSF prepupae and in the range of ratios between unsaturated and saturated fatty acids, which varied from 0.37 for cows’ milk whey to 1.34 for tomato peels and seeds. CONCLUSION: The lipids, proteins, and chitin extracted from prepupae are high-value bio-based products that could be used in the feed / food industry or for the development of innovative biomaterials, such as biodiesel. These results suggest that food-chain by-products are the best candidates for insect-bioconversion purposes. © 2020 Society of Chemical Industry
Antimicrobial biomasses from lactic acid fermentation of black soldier fly prepupae and related by-products
No full textWorldwide, thousands of insect species are consumed as food or are used as feed ingredients. Hermetia illucens, ‘black soldier fly’, is one of them, and a large amount of puparia and dead adults flies are accumulated during rearing. These materials represent important wastes but no studies are still present in the literature regarding their functional properties and potential reuse. Lactic acid bacteria (LAB) are a heterogeneous group of bacteria contributing to various industrial applications, ranging from food fermentation, chemicals production to pharmaceuticals manufacturing. A LAB feature of industrial interest is their ability to produce antimicrobial metabolites. Considering the scientific and commercial interest in discovering novel antimicrobials, this work will be direct towards fermentation of insect-derived biomasses: puparia and adults insect at the end of life cycle. To the best of our knowledge, the in vitro antimicrobial activity of fermented insects is tested for the first time. This study aimed also to evaluate differences in the composition between fermented and unfermented insects, and to study whether the fermentation and the type of LAB used played a crucial role in modifying the composition of the substrate. Results firstly highlighted fermentability of this species of insects, showed that fermented black soldier flies puparium possess a high antimicrobial activity against tested pathogens. Moreover, result of chemical composition showed that fermented biomass had a higher percentage of fat and a more complex fatty acids profile
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