In vitro assessment of protein digestibility and mineral solubility of black soldier fly larvae meals for monogastric animals

Abstract

Animal farming is a fast-growing sector which demands a large supply of feed materials and the search for novel feed ingredients with a smaller impact on the global environment has been intensified. However, before the inclusion of these feed ingredients in animal feed, a preliminary assessment of the quality and performance is needed. This evaluation is usually done by in vivo feeding trials, but in vitro digestion methods have been successfully used for gathering information regarding the nutritional value of the different feed components. Therefore, in this work, an in vitro digestion method was developed using black soldier fly (BSF) larvae meals. The method included seven experimental variables, namely: pH in stomach, pH in intestine, reaction time in stomach, reaction time in intestine, enzyme concentration in stomach, enzyme concentration in intestine and temperature. The experimental variables were screened by means of a fractional factorial design (27-2) that allowed to select the concentration of enzyme in the intestine and temperature (at 7 U and 37 °C, respectively) as the most influential factors on amino acid and mineral solubility in BSF larvae meal. Performing the in vitro digestibility at 37 °C with pH of the stomach and intestine at 2 and 9, reaction time in the stomach and intestine at 1 hour and 4 hours and concentration of enzyme in the stomach and intestine at 1 U and 7 U resulted in the highest overall nutrient solubility. This optimised in vitro digestion methodology was used to assess the nutritional stability of three batches of BSF meals delivered by the same producer. The in vitro digestion method was able to reveal differences between the three batches of BSF meals.

Assessing amino acid solubility of black soldier fly larvae meal in Atlantic salmon (Salmo salar) in vivo and in vitro

“…Moreover, gastric phase including HCl, and pepsin helps in breaking down the peptide bond and leads to higher protein hydrolysis and provides more homogenous solubility values Frontiers in Physiology frontiersin.org (Alarcón et al, 2002) than single step hydrolysis. The conditions such as temperature, pH, and reaction time selected for the in vitro solubility in this study were based on the previous studies (Eggum et al, 1989;Rahmah et al, 2016;Silva et al, 2022). The products after second step of hydrolysis were recovered to evaluate the amino acid solubility of BSF larvae meal and diets.…”

Insect meals in a circular economy and applications in monogastric diets

“… FF, full-fat insect meals; DF, defatted insect meals. a ( Weththasinghe et al, 2021 ; Leeper et al, 2022 ) b ( Heide et al, 2021 ; Weththasinghe et al, 2021 ; Gasco et al, 2022 ; Heuel et al, 2022 ; Silva et al, 2022 ) c ( Benzertiha et al, 2020 ) d ( Heide et al, 2021 ; Gasco et al, 2022 ) e ( Makkar et al, 2014 ; Hall et al, 2018 ) …”

“… b ( Heide et al, 2021 ; Weththasinghe et al, 2021 ; Gasco et al, 2022 ; Heuel et al, 2022 ; Silva et al, 2022 ) …”

Introducing the special issue ‘Insects on the monogastric menu’

“…One prerequisite is that the in vitro digestion assay simulates the digestive system of animals. Optimal experimental variables to assess the digestibility of proteins, the solubility of amino acids and minerals in black soldier fly (BSF) larvae meals were determined, and these experimental variables were evaluated on three different batches of BSF meals (Silva et al, 2022) for monogastric animals. Once the nutrient digestibility has been determined and the feeding value of the novel protein has been evaluated, the feed ingredient can be included in animal feed formulation.…”