Department of Food Engineering and Process Management, Institute of Food Sciences, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159c, 02-776 Warsaw, Poland.
Department of Chemistry, Institute of Food Sciences, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159c, 02-776 Warsaw, Poland.
Molecules. 2024 Aug 3;29(15):3679. doi: 10.3390/molecules29153679.
The growing world population necessitates the implementation of appropriate processing technologies for edible insects. The objective of this study was to examine the impact of distinct drying techniques, including convective drying at 70 °C (70CD) and 90 °C (90CD) and freeze-drying (FD), on the drying kinetics, physical characteristics (water activity, color), chemical characteristics (chemical composition, amino acid profile, oil properties, total polyphenol content and antioxidant activity, mineral composition, FTIR), and presence of hazards (allergens, microorganisms) of blanched yellow mealworm larvae. The freeze-drying process results in greater lightness and reduced moisture content and water activity. The study demonstrated that the freeze-dried insects exhibited lower contents of protein and essential amino acids as compared to the convective-dried insects. The lowest content of total polyphenols was found in the freeze-dried yellow mealworm larvae; however, the highest antioxidant activity was determined for those insects. Although the oil isolated from the freeze-dried insects exhibited the lowest acid and peroxide values, it proved to have the lowest PUFA content and oxidative stability. All the samples met the microbiological criteria for dried insects. The results of the study demonstrate that a high temperature during the CD method does not result in the anticipated undesirable changes. It appears that freeze-drying is not the optimal method for preserving the nutritional value of insects, particularly with regard to the quality of protein and oil.
不断增长的世界人口需要实施适当的食用昆虫加工技术。本研究的目的是研究不同干燥技术（包括 70°C（70CD）和 90°C（90CD）的对流干燥和冷冻干燥（FD））对干燥动力学、物理特性（水分活度、颜色）、化学特性（化学成分、氨基酸谱、油性质、总多酚含量和抗氧化活性、矿物质组成、FTIR）以及经烫漂的黄粉虫幼虫的危害物（过敏原、微生物）的影响。冷冻干燥过程导致更大的亮度和减少的水分含量和水分活度。研究表明，与对流干燥的昆虫相比，冷冻干燥的昆虫的蛋白质和必需氨基酸含量较低。在冷冻干燥的黄粉虫幼虫中发现总多酚含量最低；然而，对于那些昆虫，抗氧化活性最高。尽管从冷冻干燥的昆虫中分离出的油具有最低的酸值和过氧化物值，但它被证明具有最低的多不饱和脂肪酸含量和氧化稳定性。所有样品均符合干燥昆虫的微生物标准。研究结果表明，在 CD 方法中高温不会导致预期的不良变化。看来，冷冻干燥不是保存昆虫营养价值的最佳方法，特别是在蛋白质和油的质量方面。
