Sweers L J H, Mishyna M, Ahrné L M, Boom R M, Fogliano V, Patra T, Lakemond C M M, Keppler J K
Food Process Engineering Group, Wageningen University and Research, P.O. Box 17, 6700, AA Wageningen, the Netherlands.
Food Quality and Design Group, Wageningen University and Research, P.O. Box 17, 6700, AA Wageningen, the Netherlands.
Curr Res Food Sci. 2024 Nov 30;10:100940. doi: 10.1016/j.crfs.2024.100940. eCollection 2025.
Insect-based food ingredients are emerging as sustainable protein sources, but their production requires ensuring microbial safety and inactivation of endogenous enzymes to avoid undesirable proteolysis, without compromising protein structure. While traditional thermal processing affects the protein structure, the potential of pulsed electric field (PEF) technology to inactivate microorganisms in lesser mealworm and house cricket slurries at pH 3 while simultaneously retaining the native protein structure is yet unexplored. Lesser mealworm and house cricket slurries at pH 3 were subjected to continuous and batch PEF treatments with varying intensities (0-450 kJ/kg). Microbial inactivation (aerobes, anaerobes, yeasts, and moulds), temperature changes, protein solubility, protein structure (SDS-PAGE and FTIR), and endogenous protease activity were assessed. For both insect species, high-intensity PEF (>150 kJ/kg) achieved up to 5 log microbial reduction, but increased temperatures up to 75 °C, altering protein structure. Low-intensity PEF did not affect protein conformation and protease activity, but was not effective in microbial inactivation (<1 log reduction). We conclude that while PEF can effectively inactivate microorganisms, it cannot be considered a non-thermal method for the present sample conditions due to the temperature increase at higher intensities. PEF could be well-suitable for incorporation in hurdle techniques, such as combinations with moderate heating. Future research should investigate synergistic effects of PEF, also for using alternative PEF set-ups, with other mild processing techniques for effective microbial inactivation while preserving native protein structure. Furthermore, optimal PEF intensities for enhanced protein solubility should be explored.
以昆虫为基础的食品成分正逐渐成为可持续的蛋白质来源，但其生产需要确保微生物安全并使内源性酶失活，以避免不期望的蛋白水解，同时不破坏蛋白质结构。虽然传统热加工会影响蛋白质结构，但脉冲电场（PEF）技术在pH值为3时对黄粉虫和家蟋蟀浆液中微生物进行灭活并同时保留天然蛋白质结构的潜力尚未得到探索。将pH值为3的黄粉虫和家蟋蟀浆液进行不同强度（0 - 450 kJ/kg）的连续和间歇PEF处理。评估了微生物灭活情况（需氧菌、厌氧菌、酵母和霉菌）、温度变化、蛋白质溶解度、蛋白质结构（SDS - PAGE和FTIR）以及内源性蛋白酶活性。对于这两种昆虫，高强度PEF（>150 kJ/kg）可实现高达5个对数级的微生物减少，但温度升高至75°C，改变了蛋白质结构。低强度PEF不影响蛋白质构象和蛋白酶活性，但对微生物灭活无效（减少<1个对数级）。我们得出结论，虽然PEF可以有效灭活微生物，但由于在较高强度下温度会升高，对于当前样品条件而言，它不能被视为一种非热方法。PEF可能非常适合纳入栅栏技术，例如与适度加热相结合。未来的研究应调查PEF的协同效应，也包括使用替代的PEF设置，与其他温和加工技术协同以有效灭活微生物同时保留天然蛋白质结构。此外，应探索提高蛋白质溶解度的最佳PEF强度。
