Hsu J T, Satter L D
Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
J Dairy Sci. 1995 Jun;78(6):1353-61. doi: 10.3168/jds.S0022-0302(95)76757-1.
Soybeans were subjected to 12 heat treatments, differing in temperature and steeping (conditioning) time: control (no heat); 110 degrees C, 0 min; 110 degrees C, 30 min; 123 degrees C, 0 min; 123 degrees C, 30 min; 135 degrees C, 0 min; 135 degrees C, 30 min; 146 degrees C, 0 min; 146 degrees C, 15 min; 146 degrees C, 30 min; 153 degrees C, 30 min; and 160 degrees C, 30 min. These soybean treatments were tested for protein dispersibility index, absorbance at 420 nm, ADIN, pepsin-insoluble N, and in situ and in vitro protein degradation. Seven of these treatments (control; 123 degrees C, 30 min; 135 degrees C, 0 min; 135 degrees C, 30 min; 146 degrees C, 0 min; 146 degrees C, 30 min; and 153 degrees C, 30 min) were used in a feeding study involving 21 Holstein heifers (7 x 7 Latin square design replicated three times) and a lactation experiment (7 x 7 Latin square design replicated two times) using 14 multiparous Holstein cows in early lactation. Concentrations of branched-chain AA in blood plasma were used as indicators of protein uptake from the intestine in the heifer study, and production of 3.5% FCM was used to evaluate soybean treatments in the lactation study. Based on the criteria used, soybeans heated to 146 degrees C for 30 min were considered to be optimal. The protein dispersibility index and absorbance at 420 nm proved useful in evaluation of heat exposure of soybeans, and these procedures are suggested for routine monitoring of quality of commercially heated soybeans.
大豆接受了12种热处理，温度和浸泡（调质）时间各不相同：对照（无热处理）；110摄氏度，0分钟；110摄氏度，30分钟；123摄氏度，0分钟；123摄氏度，30分钟；135摄氏度，0分钟；135摄氏度，30分钟；146摄氏度，0分钟；146摄氏度，15分钟；146摄氏度，30分钟；153摄氏度，30分钟；以及160摄氏度，30分钟。对这些大豆处理进行了蛋白质分散指数、420纳米处的吸光度、抗消化性不可溶氮、胃蛋白酶不溶性氮以及原位和体外蛋白质降解的测试。其中七种处理（对照；123摄氏度，30分钟；135摄氏度，0分钟；135摄氏度，30分钟；146摄氏度，0分钟；146摄氏度，30分钟；以及153摄氏度，30分钟）用于一项饲养研究，该研究涉及21头荷斯坦小母牛（7×7拉丁方设计，重复三次），以及一项泌乳实验（7×7拉丁方设计，重复两次），使用14头处于泌乳早期的经产荷斯坦奶牛。在小母牛研究中，血浆中支链氨基酸的浓度用作肠道蛋白质吸收的指标，在泌乳研究中，3.5%乳脂校正乳的产量用于评估大豆处理。根据所使用的标准，加热至146摄氏度30分钟的大豆被认为是最佳的。蛋白质分散指数和420纳米处的吸光度被证明可用于评估大豆的热暴露情况，建议将这些方法用于商业加热大豆质量的常规监测。
