Kaewtapee C, Eklund M, Wiltafsky M, Piepho H-P, Mosenthin R, Rosenfelder P
J Anim Sci. 2017 Feb;95(2):779-788. doi: 10.2527/jas.2016.0932.
One batch each of eight full-fat soybeans (FFSB) was used to determine the effect of different heat treatments including wet heating (WH) and autoclaving (AC) on chemical composition and standardized ileal digestibility (SID) of CP and AA in growing pigs. The raw FFSB (K0) were either treated by WH at 80°C for 1 min (K1), at 100°C for 6 min (K2), or at 100°C for 16 min (K3). Thereafter, these batches were expanded at 125°C for 15 s. A further heat treatment included AC at 110°C for 15 (Z1), 30 (Z2), 45 (Z3), or 60 (Z4) min of FFSB that were subjected to the same WH treatment as K3. Diets were formulated to contain the respective FFSB as the sole source of CP and AA. A N-free diet was used to measure basal endogenous losses of CP and AA in an additional period at the end of the experiment. Eight ileally cannulated pigs (28 ± 1 kg) were allocated to a row-column design with 8 diets and 6 periods of 7 d each. An increase in the duration of WH had no effect on contents of AA (% of CP) and NDF, but NDIN contents linearly increased ( < 0.05) with increasing time for WH. Autoclaving resulted in a linear decrease ( < 0.05) of trypsin inhibitor activity (TIA), contents of Arg, Leu, Ala, Asp, Cys, and Gly as well as Lys to CP ratio (Lys:CP), reactive Lys to CP ratio (rLys:CP), and in an increase ( < 0.05) in contents of NDF and NDIN. There was a quadratic response ( < 0.05) of SID of CP and AA as time for WH at 100°C increased from 0 (K0) to 6 (K2) up to 16 (K3) min. Moreover, a quadratic response ( < 0.05) to increasing time of AC was observed for SID of Arg, Phe, and Pro. The SID of CP and all indispensable AA showed a quadratic response ( < 0.05) to decreasing TIA, urease activity, protein solubility in 0.2% potassium hydroxide, protein dispersibility index, Lys:CP, (lightness), and to increasing NDIN and (redness). In addition, there was a linear increase ( < 0.05) in SID values with decreasing rLys:CP and increasing NDF contents. In conclusion, WH proved to be suitable for increasing SID values. Further improvement of SID of most AA could be achieved on additional AC treatment from Z1 to Z3, however, it needs to be considered, if the observed increase due to AC is cost effective in view of the additional production costs. Several chemical and physical parameters can be used in the feed industry for quality control purposes to predict the extent of heat damage on SID of CP and indispensable AA in FFSB.
使用八批全脂大豆（FFSB）来确定不同热处理（包括湿热处理（WH）和高压灭菌（AC））对生长猪中粗蛋白（CP）和氨基酸（AA）的化学成分及标准化回肠消化率（SID）的影响。将生的FFSB（K0）分别在80°C下进行1分钟的WH处理（K1）、在100°C下进行6分钟的处理（K2）或在100°C下进行16分钟的处理（K3）。此后，将这些批次在125°C下膨化15秒。进一步的热处理包括对与K3进行相同WH处理的FFSB在110°C下进行15（Z1）、30（Z2）、45（Z3）或60（Z4）分钟的AC处理。日粮被配制为以各自的FFSB作为CP和AA的唯一来源。在实验结束时的额外时间段内，使用无氮日粮来测量CP和AA的基础内源损失。八头回肠插管猪（28±1千克）被分配到一个8种日粮和6个为期7天的时间段的行列设计中。WH持续时间的增加对AA含量（占CP的百分比）和中性洗涤纤维（NDF）没有影响，但非淀粉多糖氮（NDIN）含量随着WH时间的增加呈线性增加（P<0.05）。高压灭菌导致胰蛋白酶抑制剂活性（TIA）、精氨酸（Arg）、亮氨酸（Leu）、丙氨酸（Ala）、天冬氨酸（Asp）、半胱氨酸（Cys）和甘氨酸（Gly）的含量以及赖氨酸与CP的比率（Lys:CP）、活性赖氨酸与CP的比率（rLys:CP）呈线性下降（P<0.05），并且NDF和NDIN的含量增加（P<0.05）。随着在100°C下WH时间从0（K0）增加到6（K2）再到16（K3）分钟，CP和AA的SID呈现二次响应（P<0.05）。此外，对于精氨酸、苯丙氨酸和脯氨酸的SID，观察到对AC时间增加的二次响应（P<0.05）。CP和所有必需氨基酸的SID对TIA、脲酶活性、蛋白质在0.2%氢氧化钾中的溶解度、蛋白质分散指数、Lys:CP、（亮度）的降低以及对NDIN和（红色度）的增加呈现二次响应（P<0.05）。此外，随着rLys:CP的降低和NDF含量的增加，SID值呈线性增加（P<0.05）。总之，事实证明WH适合提高SID值。从Z1到Z3进行额外的AC处理可以进一步提高大多数氨基酸的SID，然而，鉴于额外的生产成本，需要考虑观察到的由于AC导致的增加是否具有成本效益。饲料行业可以使用几个化学和物理参数进行质量控制，以预测FFSB中CP和必需氨基酸的SID的热损伤程度。
