Zhang Junwei, Urriola Pedro E, Naeve Seth L, Shurson Gerald C, Chen Chi
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, USA.
Department of Animal Science, University of Minnesota, St. Paul, MN 55108, USA.
Antioxidants (Basel). 2023 Jul 13;12(7):1419. doi: 10.3390/antiox12071419.
Soybean meal (SBM) is a premier source of protein for feeding food-producing animals. However, its nutritional value can be compromised by protein oxidation. In this study, a total of 54 sources of solvent extracted SBM (SSBM) and eight sources of mechanically extracted SBM (MSBM), collected from different commercial producers and geographic locations in the United States during the years 2020 and 2021, were examined by chemometric analysis to determine the extent of protein oxidation and its correlation with soybean oil extraction methods and non-protein components. The results showed substantial differences between SSBM and MSBM in the proximate analysis composition, protein carbonyl content, lipidic aldehydes, and antioxidants, as well as subtle differences between 2020 SSBM and 2021 SSBM samples in protein oxidation and moisture content. Correlation analysis further showed positive correlations between protein carbonyl content and multiple lipid parameters, including the ether extract, -anisidine value, individual aldehydes, and total aldehydes. Among the antioxidants in SBM, negative correlations with protein carbonyl content were observed for total phenolic content and isoflavone glycoside concentrations, but not for Trolox equivalent antioxidant capacity (TEAC), α-tocopherol, and γ-tocopherol. Overall, soybean oil extraction methods, together with other factors such as enzyme treatment and environmental conditions, can significantly affect the proximate analysis composition, the protein and lipid oxidation status, and the antioxidant profile of SBM. Lipidic aldehydes and phenolic antioxidants play counteracting roles in the oxidation of soy protein. The range of protein carbonyl content measured in this study could serve as a reference to evaluate the protein quality of SBM from various sources used in animal feed.
豆粕（SBM）是用于喂养食用动物的优质蛋白质来源。然而，其营养价值可能会因蛋白质氧化而受到影响。在本研究中，于2020年和2021年从美国不同商业生产商和地理位置收集了总共54种溶剂萃取豆粕（SSBM）来源和8种机械萃取豆粕（MSBM）来源，通过化学计量分析来确定蛋白质氧化程度及其与大豆油提取方法和非蛋白质成分的相关性。结果表明，SSBM和MSBM在近似分析组成、蛋白质羰基含量、脂质醛类和抗氧化剂方面存在显著差异，2020年SSBM和2021年SSBM样品在蛋白质氧化和水分含量方面也存在细微差异。相关性分析进一步表明，蛋白质羰基含量与多种脂质参数呈正相关，包括醚提取物、对茴香胺值、单个醛类和总醛类。在SBM中的抗氧化剂中，总酚含量和异黄酮糖苷浓度与蛋白质羰基含量呈负相关，但Trolox等效抗氧化能力（TEAC）、α-生育酚和γ-生育酚则不然。总体而言，大豆油提取方法以及酶处理和环境条件等其他因素会显著影响SBM的近似分析组成、蛋白质和脂质氧化状态以及抗氧化剂谱。脂质醛类和酚类抗氧化剂在大豆蛋白氧化中起相反作用。本研究中测得的蛋白质羰基含量范围可作为评估动物饲料中使用的各种来源SBM蛋白质质量的参考。
