Edible insects represent an interesting alternative source of protein for human consumption but the main hurdle facing the edible insect sector is low consumer acceptance. However, increased acceptance is anticipated when insects are incorporated as a processed ingredient, such as protein-rich powder, rather than presented whole. To produce edible insect fractions with high protein content, a defatting step is necessary. This study investigated the effects of six defatting methods (conventional solvents, three-phase partitioning, and supercritical CO2) on lipid extraction yield, fatty profiles, and protein extraction and purification of house cricket (Acheta domesticus) and mealworm (Tenebrio molitor) meals. Ethanol increased the lipid extraction yield (22.7%–28.8%), irrespective of the insect meal used or the extraction method applied. Supercritical CO2 gave similar lipid extraction yields as conventional methods for Tenebrio molitor (T. molitor) (22.1%) but was less efficient for Acheta domesticus (A. domesticus) (11.9%). The protein extraction yield ranged from 12.4% to 38.9% for A. domesticus, and from 11.9% to 39.3% for T. molitor, whereas purification rates ranged from 58.3% to 78.5% for A. domesticus and from 48.7% to 75.4% for T. molitor.

Despite extensive research on the topic, valorization of dairy by-products remains challenging. Cheese whey is of particular interest because it contains valuable proteins such as α-lactalbumin (α-LA) and β-lactoglobulin (β-LG). However, selective fractionation of these 2 proteins into pure fractions is complex because of their similar molecular weights. In this study, we proposed an innovative protein separation strategy based on coupling high hydrostatic pressure (HHP) with acidification of whey at pH 4.6. We investigated the effect of single-cycle HHP (600 MPa) for 5, 10, and 15 min and multiple-cycle HHP (1-3 cycles of 5 min at 600 MPa) on α-LA and β-LG fractionation from cheese whey at initial pH (control, pH 6.66) and acidified to pH 4.6. All pressurization conditions with acidified whey induced a drastic aggregation of β-LG compared with control whey. The highest degrees of purification (75 and 98%, respectively) and yields (95 and 88%, respectively) of α-LA and β-LG were obtained with the application of single-cycle HHP treatment of acidified whey at pH 4.6 at 600 MPa for 5 min. Our results showed the strong potential of using HHP as an innovative tool for the fractionation of valuable proteins such as α-LA from cheese whey.

Edible insects have garnered increased interest as alternative protein sources due to the world’s growing population. However, the allergenicity of specific insect proteins is a major concern for both industry and consumers. This preliminary study investigated the capacity of high hydrostatic pressure (HHP) coupled to enzymatic hydrolysis by Alcalase® or pepsin in order to improve the in vitro digestion of mealworm proteins, specifically allergenic proteins. Pressurization was applied as pretreatment before in vitro digestion or, simultaneously, during hydrolysis. The degree of hydrolysis was compared between the different treatments and a mass spectrometry-based proteomic method was used to determine the efficiency of allergenic protein hydrolysis. Only the Alcalase® hydrolysis under pressure improved the degree of hydrolysis of mealworm proteins. Moreover, the in vitro digestion of the main allergenic proteins was increased by pressurization conditions that were specifically coupled to pepsin hydrolysis. Consequently, HHP-assisted enzymatic hydrolysis represents an alternative strategy to conventional hydrolysis for generating a large amount of peptide originating from allergenic mealworm proteins, and for lowering their immunoreactivity, for food, nutraceutical, and pharmaceutical applications.

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Few data are available concerning the composition of biofilms found at the surface of filtration membranes, which, to some extent, explains the long-term failure of numerous strategies developed to control biofouling. This preliminary study intended to design a metagenomic tool targeting the 16S rRNA gene in order to unravel a general portrait of bacterial communities found on spiral-wound membranes used in the dairy industry. A total of seven spiral-wound membrane elements (ultrafiltration, nanofiltration, or reverse osmosis) at the end of their useful lifetimes were collected from different dairy plants. Targeted analysis of the 16S rRNA genes of the metagenome extracted from the membranes revealed their bacterial diversity via high-throughput sequencing technology (Miseq, Illumina). It was found that the nature of the filtered fluid (milk, whey, water) explained 58.6 % of the variance observed between communities found on membranes. Treatments applied on dairy fluids (milk pasteurization, whey bleaching or whey ultrafiltration) induced a selective pressure that affected the diversity of bacterial communities found on membranes and the proportions of spore-former bacteria among them. This work provides the first complete bacterial portrait of the biofilm composition of spiral-wound membranes used in the dairy industry. It suggests that the nature of the filtered fluid and potentially filtration Dairy Sci. & Technol. (2017)