Department of Animal and Poultry Science, College of Agricultural and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China.
Department of Animal and Poultry Science, College of Agricultural and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada.
Animal. 2021 Feb;15(2):100046. doi: 10.1016/j.animal.2020.100046. Epub 2021 Jan 22.
The objective of this study was to explore if microwave irradiation and moist autoclaving treatments could change nutritive values, nutrients availability and protein inherent spectral structural characteristics in tannin (var. Fatima) and non-tannin (var. Snowbird) faba beans. An in situ approach with four cannulated dry Holstein dairy cows was applied in this study. The results showed that beans heated with microwave and autoclaving had increased contents of ether extract and neutral detergent insoluble CP and reduced soluble CP, sugar and tannin concentrations when compared with the raw seeds. Heating reduced degradable nutrients in the rumen and increased intestinally absorbable nutrients, but it failed to improve digestibility in total tract. All the results showed heating with moisture and pressure would be stronger and severer than microwave irradiation. The variety of faba bean interacted with thermal treatment on total truly intestinally absorbed protein value which showed to be highest in the microwaved brown faba bean and lowest in the unheated Snowbird bean. The degraded protein balance (OEB) value was significantly decreased after both kinds of heating process, suggesting that heating treatments could mitigate loss of nitrogen from the rumen to a large extent. We further collected spectral data using mid-IR spectroscopy and found heat processed beans had varied peak height and area ratios compared with raw beans. However, multivariate results implied that heating process failed to completely change the whole molecular conformation in the protein amide region. Correlations were found between ADF/ADL and spectral features, and the OEB value was negatively related to protein secondary structural α-helix. In conclusion, both faba beans were more sensitive to autoclaving treatment than microwave irradiation in terms of nutrient availability in ruminants.
本研究旨在探讨微波辐射和湿热高压处理是否会改变单宁（Fatima 品种）和非单宁（Snowbird 品种）蚕豆的营养价值、养分有效性和蛋白质固有光谱结构特征。本研究采用了 4 头带有套管的干荷斯坦奶牛进行了体内试验。结果表明，与未加热的生种子相比，经微波和高压湿热加热的豆类，其乙醚提取物和中性洗涤不溶性 CP 含量增加，而可溶性 CP、糖和单宁浓度降低。加热降低了瘤胃中可降解的养分含量，增加了肠道可吸收的养分，但未能提高全肠道的消化率。所有结果表明，湿热处理比微波辐射更强、更剧烈。蚕豆品种与热处理对总真正肠道可吸收蛋白质值的相互作用表明，微波加热的褐色蚕豆最高，未加热的 Snowbird 豆最低。两种加热过程后，降解蛋白平衡（OEB）值均显著降低，表明加热处理可在很大程度上减少氮从瘤胃中的损失。我们进一步使用中红外光谱法收集了光谱数据，发现与生豆相比，经热处理的豆的峰高和峰面积比发生了变化。然而，多元结果表明，加热过程未能完全改变蛋白质酰胺区域的整个分子构象。ADF/ADL 与光谱特征之间存在相关性，OEB 值与蛋白质二级结构α-螺旋呈负相关。总之，在反刍动物中，与微波辐射相比，两种蚕豆对湿热高压处理在养分有效性方面更为敏感。
