Wheat Bran Research Articles

Olfactory response and food preference of Gromphadorhina portentosa (Blattodea: blaberidae) to agro-industrial waste for biomass production

The Madagascar cockroach (Gromphadorhina portentosa) is a species widely used in insect farming, including in animal and human diets. Because of these potential applications, we are looking for effective ways to breed them in captivity, through alternatives that reduce production costs. One solution to this problem would be to use agro-industrial waste to feed these insects. Therefore, this study aimed to evaluate the olfactory behavior of the Madagascar cockroach when exposed to different agro-industrial residues. The experiments were conducted at the Entomoculture Laboratory of the Federal Rural University of Pernambuco (UFRPE) using agro-industrial waste from sugarcane bagasse (Saccharum spp.), forage palm (Opuntia ficus), moringa (Moringa oleifera L.), and wheat bran (Triticum vulgare). The waste was distributed randomly in the evaluation arena. There were 20 repetitions of both sexes with an evaluation period of 20 min each. The bioassays were carried out in sequence: response time of the cockroaches, first olfactory choice, and food preference. Males and females had the highest average consumption in the 20-min evaluation period, and the first olfactory choice was for moringa; however, food preference was concentrated on wheat bran, where females had an average consumption of 1.3g of wheat bran and males 0.85g. Therefore, using wheat bran could make large-scale production of Madagascar cockroaches feasible and potentially make it possible to reuse and sustainably use this waste.

Antidiabetic Potential of Hylocereus Polyrhizus and Hylocereus Megalanthus Fruit Peel: An In vitro Study

ABSTRACT Background: Diabetes is a chronic metabolic condition affecting mainly carbohydrate metabolism. Dragon fruit is a commonly consumed fruit in Asia-pacific countries, with reported anti-diabetic potential. Objectives: The presents study explores the use of dragon fruit peel as an anti-diabetic supplement. Materials And Method: Fruit peels from two varieties (Red and Yellow) were evaluated for their ability to absorb glucose, inhibit glucose diffusion, and inhibit starch digestion using in vitro models. Result: Both red and yellow dragon fruit peel powder samples decreased starch digestion significantly compared to wheat bran and inhibited glucose diffusion, as indicated by the glucose dialysis retardation index (GDRI) values. Conclusion: The findings of the study indicate that both red and yellow dragon fruit peel possesses significant antidiabetic potential.

Characterization of wheat bran nanocellulose and its application in low-fat emulsified sausage

Characterization of wheat bran nanocellulose and its application in low-fat emulsified sausage

Optimized Polyhydroxybutyrate Production by Neobacillus niacini GS1 Utilizing Corn Flour, Wheat Bran, and Peptone: A Sustainable Approach

Plastic pollution is a pressing environmental challenge, necessitating the development of biodegradable alternatives like polyhydroxybutyrate (PHB). This study focuses on optimizing PHB production by Neobacillus niacini GS1, a bacterium isolated from a municipal dumping site. By utilizing agricultural residues such as corn flour, wheat bran, and peptone as substrates, we aimed to establish an eco-friendly method for biopolymer production, contributing to sustainable agricultural residue management and bioplastic innovation. The bacterium was identified using morphological, biochemical, and molecular techniques. The optimization process involved adjusting variables such as inoculum age, inoculum size, incubation time, agitation rate, incubation temperature, pH of the medium, carbon sources, and nitrogen sources. Response surface methodology (RSM) was employed to identify optimal conditions, with the highest PHB yield of 61.1% achieved under specific conditions: 37 °C, pH 7, and an agitation rate of 150 rpm. These findings underscore the potential of Neobacillus niacini GS1 in converting agro-industrial residues into valuable biopolymers, promoting sustainable bioplastic production, and advancing agricultural residue valorization efforts through the use of eco-friendly materials.

Amino acid requirements of yellow mealworm and black soldier fly larvae

Abstract In order to achieve optimal growth and health of farm animals, a different amount/ratio of essential amino acids in the feed is necessary in each phase of life. Knowledge about which amino acids are essential and in which quantities/proportions they are best administered has already greatly advanced the pig and poultry sector and is still being generated today. For the still young, rapidly developing insect sector, this knowledge could mean a major step forward towards breeding optimization. Therefore, in this research the needs of the 2 most commercially reared insect species, namely mealworms (Tenebrio molitor) (MW) and black soldier fly larvae (Hermetia illucens) (BSF), were investigated. The focus was on requirements for lysine, methionine, threonine, phenylalanine and tryptophan based on evidence from the literature and those of pigs. Semi-artificial diets based on at least 25% wheat bran (MW) and chicken feed/water (30/70) (BSF) (basic feed important for structure and certain micronutrients) supplemented with sugar and synthetic amino acids were tested. The diets were isoenergetic and isoproteinous. Of the amino acids studied, one was administered in different doses per experiment. The non-essential glutamic acid was used as a substitute at lower doses. Growth, as measured by weight gain, and survival were observed. The following results were for MW and BSF respectively. For lysine from a content of 0.35 g/100 g diet and 0.53 g/100 g diet no extra growth was noticeable. For methionine this was from 0.13 g/100 g and 0.16 g/100 g. Each time more threonine was given, a significant difference could be noticed and the minimum doses were around 0.42 g/100 g and 0.49 g/100 g. With tryptophan, for MW, there were no differences between the different concentrations. At the lowest dose of 0.06 g/100 g the maximum growth was already reached, whereas for BSF this was at 0.13 g/100 g.

Ensiling as a Conservation Technique for Opuntia ficus indica (L.) By-Products: Peel and Pastazzo

Italy is the third largest producer of Opuntia fruits in the world after Mexico and the United States, and 97.72% of these fruits produced by Italy are grown in Sicily. The use of prickly pear fruits or juice leads to a high production of by-products. In this study, ensiling was chosen to preserve prickly pear peels (PPPs) and “pastazzo” (PPS) mixed with 12% wheat bran. PPP silage presented a lower DM than PPS silage (20.03 vs. 41.37%; p < 0.01), as well as aNDFom (25.31 vs. 66.66% DM; p < 0.01), but had the best protein content (12.02 vs. 9.55% DM; p < 0.01). For both by-products, fermentation proceeded rapidly with increasing temperature, with the temperature for PPS (38 °C) being higher than that for the PPP (30 °C). Mesophilic LAB (lactic acid bacteria) were detected at higher levels than thermophilic LAB, and rod counts were higher than cocci counts. The detected organic acids and silage pH indicate an optimal fermentation process for these by-products. PPP silage had a higher polyphenol content than PPS silage (30.24 vs. 24.22 mg GAE/g DM; p < 0.01) and, consequently, also higher antioxidant activity. The results of this study on the mineral composition and macro- and micro-nutrients in silage highlight that these by-products are sources of minerals, with high levels of potassium, calcium, and magnesium.

Insight into the conformational changes and allergenic reactivity of coarse wheat bran induced by ozone treatment.

Whole grain food has gradually come into view because of its high nutritional value, but the incidence of wheat allergies has been increasing year by year. Ozone is a new non-thermal desensitization technology in food processing, and its effect on coarse wheat bran protein has received little study. We investigated the effects of different ozone airflow rates and treatment times on wheat bran allergenic property and protein structure. The ozone treatment time of 30 min at an airflow rate of 5 L min-1 reduced the coarse wheat bran allergenic property by 61.14%; subunits of 33, 46, 48 and 68 kDa were significantly less allergenic via western blotting; and the lowest releasing rate of β-hexosaminidase was 25.32% in the cell model of rat basophilic leukaemia 2H3. According to secondary structure and chemical interaction determination, the protein molecules were reorganized and aggregated by disulfide bonds and hydrophobic contacts following ozone exposure. Ozone treatment has a beneficial potential in reducing the allergenic property of coarse wheat bran and improving the safety of whole wheat products. © 2024 Society of Chemical Industry.

Dietary Influence on Growth, Physicochemical Stability, and Antimicrobial Mechanisms of Antimicrobial Peptides in Black Soldier Fly Larvae

Safe antibiotic substitutes are needed given the rise in antimicrobial resistance, environmental contamination, and stringent antibiotic regulations. Insect-derived antimicrobial peptides (AMPs) are promising candidates due to their antimicrobial activity, stability, and safety. This study investigates the antimicrobial mechanism of crude AMP extracts and their physicochemical characteristics in black soldier fly larvae (BSFL). The results indicated that BSFL reared on a wheat bran diet exhibited significantly improved growth performance and AMP production when compared to the other three diets. AMP extracts showed enhanced antimicrobial activity and physicochemical stability, including temperatures and metal ions except Cu+. Moreover, AMP extracts disrupted the cell membrane and inhibited the cell cycle of Staphylococcus aureus (S. aureus), thus exhibiting antimicrobial activity. Furthermore, transcriptomic and KEGG enrichment analyses identified 509 differentially expressed genes (DEGs) related to the Toll and IMD signaling pathways. STRING and GeneMANIA analyses confirmed the association of these pathways with immune response and AMP secretion. qRT-PCR results showed elevated expression of immune genes (GNBP3, NFKBIA, GADD45, and Spz) in BSFL following S. aureus immunization, consistent with RNA-seq findings. These findings offer a valuable reference for using AMPs as antibiotic substitutes in animal feeds and highlight the need for further research on AMP purification and the synergistic regulation of protein synthesis and AMP production in BSFL.

Impact of Providing Cowpea (Vigna unguiculata) Hay, Wheat Bran, and Their Mixes on Begait Lambs' Skin and Leather Quality

Aims: To evaluate the impact of adding wheat bran (WB), cowpea hay (CPH), or mixes of the two on the chemical and physico-mechanical properties of leather. To determine the ideal ratio for supplementing wheat bran and cowpea hay on the chemical and physico-mechanical properties of leather. Study Design: The study employed a randomized complete block design (RCBD) with five treatments and blocks. Place and Duration of Study: Northern Ethiopia, Humera Agricultural Research Center farm, starting from December 2016 until November 2017. Methodology: 25 intact male Begait lambs were bought from the local market, weighing an average of 28.02 ± 1.49 kg (mean ± SD) at 5 to 6 months of age. Based on their starting body weight, they were split into five groups and assigned randomly to each of the five treatments. The standard diet for T1, T2, T3, T4, and T5 consisted of giving natural grass hay ad libitum plus supplements of 300 g CPH, 225 g CPH + 75 g WB, 150 g CPH + 150 g WB, 75 g CPH + 225 g WB, and 300 g WB DM day-1. Three lambs per treatment were randomly chosen, slaughtered, and dressed down using standard commercial techniques at the end of the feeding trial to assess the quality of skin and leather. Results: Compared to the other treatment groups, the Begait lambs in T2 and T3 exhibited increased tensile strength, elongation strength, and thickness. However, the chemical makeup of skin was comparable between treatment groups. Conclusion: Therefore, this study concluded that all test diets generated skin and leather that largely complied with the chemical and physico-mechanical quality standards demanded by the leather industry.

Effects of water-insoluble wheat bran-fraction powder on disease activity and caecal microbiota in dextran sodium sulphate-induced inflammatory bowel disease mouse model.

Water-soluble arabinoxylan exerts anti-colitic effect and exhibits ameliorative activity in an inflammatory bowel disease (IBD) mouse model. Water soluble fibre from wheat bran (WB) also exhibits anti-colitic effect. However, arabinoxylan is a primary compound of insoluble polysaccharide (hemicellulose) in WB. This study aimed to clarify the anti-IBD effects of the WB water-soluble (WBS) and water-insoluble (WBI) fractions. WB suspension was autoclaved and fractionated to WBS and WBI. C57BL/6 mice were divided into control (CT), dextran sodium sulphate (DSS), WBI, and WBS groups. They were fed as follows from day 1: CT, standard diet and distilled water; DSS and WBI, 3% (w/v) DSS in drinking water; WBI, 8% (w/w) WBI diet; and WBS, 50% (v/v) WBS and 3% (w/v) DSS in water. DSS group mice showed diarrhoea, body weight reduction, and blood in faeces by day 5 and colon tissue damage by day 6. These inflammatory indices were significantly inhibited by treatment with WBI. Amplicon sequencing of the 16S rDNA (V4) gene of the caecal contents of the CT, DSS, and WBI groups showed that the abundances of Escherichia, Allobaculum, and Bacteroidaceae increased and that of Faecalibaculum decreased in the DSS group. KEGG pathway prediction showed that amino acid metabolism and lipopolysaccharide biosynthesis decreased and increased, respectively, in the DSS group. However, WBI treatment tended to suppress these effects. WBI, rather than WBS, reduces inflammation and maintains the gut microbiota. However, further studies are warranted to elucidate the properties of the WBI active components and efficacy of WBI metabolites on gut microbiota, particularly on Faecalibaculum.

Nutritive Value of Some Concentrate Feedstuffs for Guinea Pigs (Cavia porcellus).

The objective of this work was to ascertain the nutritive value of six concentrate feedstuffs commonly used in guinea pig feed manufacturing through the substitution method. Six test diets were obtained by replacing the corresponding basal mixture with 40% corn, 50% barley, 45% wheat bran, 35% soybean meal, 30% pigeon pea, or 30% Leucaena leaf meal. Sixty-three guinea pigs were randomly assigned to one of the nine experimental diets (three basal diets and six test diets, with seven animals per diet). The animals were housed in individual cages and provided with feed and water ad libitum. Following a ten-day adaptation period, the feed intake and faeces excretion were monitored for a further five days. The digestible energy content, expressed as kcal/kg dry matter (±standard error), was 3857 ± 83 for corn, 3454 ± 68 for barley, 2911 ± 110 for wheat bran, 3855 ± 81 for soybean meal, 3105 ± 79 for pigeon pea, and 2972 ± 72 for Leucaena leaf meal. The apparent total tract digestibility of crude protein, expressed as % (±standard error) was 73.8 ± 4.9 for corn, 69.5 ± 4.6 for barley, 76.4 ± 3.6 for wheat bran, 88.4 ± 1.0 for soybean meal, 62.1 ± 1.9 for pigeon pea, and 68.0 ± 1.8 for Leucaena leaf meal. Further research is required to increase knowledge about these and other feedstuffs for guinea pigs.

Make it a standard? The creation and variability assessment of a consensus standard protocol for Tenebrio molitor larvae feeding trials

Abstract Interest in the nutrition of the yellow mealworm (Tenebrio molitor L.) larvae is on the rise, leading to an increase in publications on this topic. The absence of a standard protocol and resulting differences in experimental designs reduces comparability among studies and impedes research on mealworm nutrition. To address this, a consensus standardised protocol was developed specifically for the evaluation of mealworm larval growth and performance in feeding trials. The efficacy of this protocol was evaluated through an international ring test involving seven partners using two wheat brans as dry feed (a standard bran and a local bran) at 27 °C and 60% relative humidity. As experimental units, plastic crates filled with 2.1 kg of bran and 10,000 4-week-old larvae were used with six replicates. Agar gel was provided as wet feed ad libitum. The mean individual larval weight and the number of larvae per crate were determined weekly until either three or more replicates ran out of feed or pupation exceeded 10%. At harvest, the total larval fresh biomass and amount of frass was determined. Larval samples were taken for chemical analysis. To assess the protocol, the within (repeatability) and between (reproducibility) laboratory variability was calculated for each parameter. The repeatability was good (limit at 12% (standard) and 14% (local)). The reproducibility was poorer with a limit 2.7 times higher for the standard feed (36%) and 3.8 times higher for the local feed (55%). For both feeds, the total larval fresh harvest, amount of frass and the larval protein concentration were the most consistent both within and among laboratories. The highest variability was observed at the early life stages and for the larvae ash content. The detailed consensus standard protocol and repeatability/reproducibility estimates can be used as basis for future mealworm feeding trials, comparing results and future improvements.

Promoting the grinding of wheat bran through treatment by sodium carbonate and its mechanism

This work investigated the effect of treatment by sodium carbonate on grinding of wheat bran and the related mechanism. Specifically, wheat bran was treated by sodium carbonate solutions at the ratio of 1:2 to make addition of sodium carbonate at 0.0%, 4.0%, 8.0%, 12.0%, 15.0%, and 30.0% based on the mass of bran, dried, and ground using the universal high-speed grinder. It was found that treatment by sodium carbonate significantly reduced the particle size of ground bran and this effect was positively correlated with the sodium carbonate content, which suggested that treatment by sodium carbonate promoted the grinding of wheat bran. Besides, treatment by sodium carbonate improved the hardness of bran. On the other hand, treatment by sodium carbonate damaged the crystal structure, the cell wall and lignin of bran. Moreover, treatment by sodium carbonate converted bound phenolics, including ferulic acid, into free phenolics and insoluble dietary fiber, including unextractable arabinoxylan, into soluble dietary fiber. These results suggested that treatment by sodium carbonate had already damaged the structure of bran and altered the texture of bran before the mechanical stress during grinding was applied. As a result, treatment by sodium carbonate promoted the grinding of wheat bran.

Effect of Processed Coffee Husk on Feed Intake, Nutrient Digestibility, Body Weight Changes and Economic Feasibility of Bonga Sheep Fed on Natural Pasture Hay as a Basal Diet.

Ethiopia is one of the world's coffee producers, generating about 192,000 metric tonnes of coffee husks annually as by-products. The material can be used for ruminant diets to improve the nutrient utilisation of animals. However, coffee husk has toxic compounds, which can be minimised through different processing methods. Though the above techniques can minimise the toxicity level of coffee husk and increase the bioavailability of nutrients, there is scanty information on the comparative efficacy of these techniques, especially in ruminant nutrition. The study was conducted to examine the effect of processed coffee husk on feed intake, nutrient digestibility, body weight changes and profitability of Bonga rams based on natural pasture hay. In the experiment, 24 rams were used, and the rams were grouped into six blocks based on initial body weight (mean BW 21.5 ± 1.01kg). The rams were quarantined for 21 days, and each ram was randomly assigned to one of the experimental feed treatments in a randomised complete block design (RCBD). The experimental treatment feeds include 400g conventional concentrate mix (CM) containing Noug seed cake and wheat bran (T1); 200g boiled coffee husk + 200g CM (T2); 200g roasted coffee husk + 200g CM (T3) and 200g raw coffee husk + 200g CM (T4). The CM was made in the ratio of 1:1. The data collected from the 90-day experimental period were: dry matter and nutrient intakes, initial body weight, final body weight and body weight changes. After the growth experiment, a 7-day digestibility trial was followed by collecting faeces using a harness bag. The data were managed using Microsoft (MS) Excel 2010 and analysed using R software (v. 4.3.2). The chemical compositions of the CM had maximum crude protein (22%), followed by boiled coffee husk (14.74%), which was higher than natural pasture hay (6.91%) and raw coffee husk (12.4%). The total dry matter intake (p < 0.05), metabolisable energy, and total nutrient intakes of rams were significantly (p < 0.001) maximised when rams fed on boiled coffee husk (T2) than raw (T4) and roasted (T4) coffee husk, except for NDF and organic matter intakes. The apparent digestibility of nutrients and feed conversion efficiency were maximised for rams assigned to T2. There was maximum daily body weight gain (p < 0.001) when rams were supplemented with boiled coffee husk (T2). Also, body weight changes of rams were significantly (p < 0.001) higher for rams supplementation with boiled coffee husk. Therefore, the boiled coffee husk as an alternative feed resource can be replaced by about half of the commercial CM without adverse effects of anti-nutritional factors and enhance the income of smallholder farmers in the coffee crop-livestock production system.

Preparation and characterization of ferulic oligosaccharides from different sources by cell-free GH10 and GH11 xylanases

The feruloyl oligosaccharides (FOs) produced by the decomposition of plant hemicellulose have broad potential applications in the food and biomedical areas. FOs were prepared through the specific enzymatic degradation of insoluble dietary fiber from different sources by cell-free GH10 and GH11 xylanases. The cell-free GH10 and GH11 xylanases were obtained by the heterologous expression in Escherichia coli. The enzymatic hydrolysis conditions were optimized as follows: temperature 50 °C, pH 5.5, hydrolysis time 12 h, GH10 xylanase addition 101.74 U, and GH11 xylanase addition 121.60 U. The compositions and structural characterization of wheat bran FOs (WB-FOs), corncob FOs (CC-FOs), and buckwheat straw FOs (BS-FOs) were identified by fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), high-performance liquid chromatography (HPLC), and electrospray ionization tandem mass spectrometry (ESI-MS). Degrees of polymerization (DP) of WB-FOs, CC-FOs, and BS-FOs were 3–11, 3–7, and 3–6, respectively. Ultraviolet (UV) radiation was investigated in vitro. The results demonstrated that BS-FOs possessed excellent UV resistance and photostability, followed by effectiveness in WB-FOs and CC-FOs. These results have improved our understanding of the relationship between FOs with different structural types and their UV radiation.

Disintegration of commercial single-use plastics from synthetic and biobased origins and effects on plant growth

Many single–use plastic (SUP) options made of synthetic polymers, bio-based materials, and blends of both are available in the market and used in large quantities. The disintegration of eleven commercial SUP, marketed in Mexico as cups and plates, was investigated in an aerobic home compost environment at a laboratory scale over 180 days. An evaluation of chemical changes, surface morphology, and thermal and mechanical properties was conducted to ascertain the original composition of SUP and the progression of disintegration in samples that are challenging to clean from soil contamination. Furthermore, the impact of residual compost on barley (Hordeum vulgare) plant growth and its correlation with the leaching of heavy metals were explored. The bio-based SUP, but not those made of expanded polystyrene foam, showed a correlation between the disintegration degree (measured by weight loss into particles <2 mm) and a decrease in functional groups (observed by FT-IR), mechanical-thermal stability loss, and surface wear over disintegration time. For instance, the highest disintegration at 180 days was approximately 70% for wheat bran and palm leaf plates, followed by wheat plates and cellulose-PLA cups (60%). In addition to the components listed by the manufacturers, the FT-IR and DSC analysis revealed the presence of polyethylene and polypropylene in cellulose cups and sugarcane plates. These components, impede disintegration but contribute to preserving thermal resistance and hydrophobicity during utilization. Compost derived from expanded polystyrene foam SUP, with 90 days of disintegration, was rich in zinc and chromium and significantly decrease in the root length of the barley plant compared to the control. This demonstrates the necessity of considering the impact of the leaching of additives and secondary microplastics into the environment.

Modification of black wheat bran by superfine grinding and Neurospora crassa fermentation: physicochemical properties, mixed flour quality, steamed bread quality, and flavor

Modification of black wheat bran by superfine grinding and Neurospora crassa fermentation: physicochemical properties, mixed flour quality, steamed bread quality, and flavor

Effects of interaction between wheat bran dietary fiber and gluten protein on gluten protein aggregation behavior.

Effects of wheat bran dietary fiber (WBDF) as a nutritional additive on flour products quality mainly depends on the interaction between WBDF and gluten protein. In this study, the effects and mechanisms of WBDF with different particle sizes and additive amounts on gluten protein aggregation behavior were investigated. The results showed that the addition of WBDF led to a decrease in free sulfhydryl content, particle size, molecular weight and gluten macromer (GMP) content, an increase in zeta potential and SDS-extractable protein content, and a deterioration in the gluten network morphology compared to the control group, suggesting that the aggregation behavior of gluten protein was inhibited. When WBDF was added at 3 % and 6 %, dilution effect, mechanical shear, steric hindrance, and non-covalent binding were the main mechanisms leading to depolymerization. Further addition of WBDF (9 %, 12 %) inhibited the depolymerization of gluten protein due to competitive hydration and non-covalent binding. However, when WBDF was added at 15 %, the dilution effect, mechanical shear and steric hindrance of WBDF (88 μm < particle size<150 μm) dominated, and their inhibitory of aggregation induced the formation of a loose gluten network structure. In contrast, the weaker mechanical shear and steric hindrance effects of WBDF (particle size<88 μm) mitigated the degradation of gluten network structures by WBDF.

Adhesive solid-state fermentation producing Aspergillus niger conidia on stainless-steel dixon ring supports.

An adhesive solid-state fermentation (adSSF) mode was developed to produce Aspergillus niger conidia, which used a stainless-steel Dixon ring as the support and water-retaining adhesive to load nutritional media on its surface. To obtain high conidia yields, the components of the water-retaining adhesive were screened, optimized by single-factor optimization and response surface methodology, and the optimal dosages of the main components were: wheat bran powder 0.023g·cm-3bed, cassava starch 0.0022g·cm-3bed, and xanthan gum 0.0083g·cm-3bed. The experimentally tested conidia yield was 4.2-fold that without water-retaining adhesive but was 3.7% lower than the maximum yield predicted by the model. The observed double-side growth of A. niger on the Dixon ring supports improved space utilization of the fermentation bed, and the void fraction can increase with the shrinkage of the gel layer. In 1.6L tray reactors with three-point online temperature monitoring, the inner-bed temperature of adSSF was at most 4°C lower than the adsorbed carrier solid-state fermentation (ACSSF) mode, and the conidia yield was 1.68 × 108 conidia.cm-3bed, 61.5% higher than that of the ACSSF bed at the same time, but when the fermentation time was extended to 168h, the conidia yield of the adSSF bed and ACSSF bed were close to each other. The results revealed that the high voidage of the adSSF bed was the main reason for low bed temperature, which can benefit the inner-bed natural convection and water evaporation.

Black soldier fly larvae (Hermetia illucens) do not bioaccumulate ferulic and caffeic acids from wheat bran

Abstract As recently shown, black soldier fly larvae (BSFL) are capable of bioaccumulating high concentrations of vitamin E and carotenoids, but the potential bioaccumulation of polyphenols remains unknown. Wheat bran (WB), a common breeding substrate for BSFL, is particularly rich in ferulic acid (FA) and also contains caffeic acid (CA). Numerous studies suggest that these polyphenols have beneficial effects on human and animal health. BSFL ability to bioaccumulate these bioactive compounds was assessed by comparing their concentration in WB and BSFL raised on WB. The three forms of FA and CA, i.e. free, soluble-bound and insoluble-bound, were extracted from WB and BSFL and quantified by HPLC-UV. No form of CA was detected in BSFL. The three forms of FA were detected but the total FA concentration in BSFL (17 ± 1 mg/kg fresh weight) represented only 2% of the total FA concentration measured in WB (810 ± 38 mg/kg fresh weight). Since the larvae were not fasted, another experiment was carried out to find out if the small amount of FA found in the larvae was the FA contained in WB present in their digestive tract. The digestive tracts of fasted and non-fasted larvae at the end of the rearing period were weighted. And it was calculated that all the FA measured in the larvae could be the FA present in their digestive tract. Moreover, the distribution of the three different forms of FA differed between WB and BSFL. Therefore, we have demonstrated that not only BSFL do not significantly bioaccumulate FA from WB but that they apparently metabolize it. Regarding CA as a precursor of FA, the same phenomenon might have happened. However, assuming an equivalent bioaccumulation factor as FA, the amounts of CA theoretically transferred in larvae were too low to be detected.