Influence of various methods of processing soybeans on protein digestibility and reduction of nitrogen deposits in the natural environment - a review
大豆加工方法对蛋白质消化率和减少环境氮沉积的影响——综述。
摘要 (Abstract)
<jats:title>Abstract</jats:title> <jats:p> Soybean meal (SBM) is a significant source of protein for poultry due to its high concentration of protein and amino acids profile. The primary objective of SBM processing is the reduction and deactivation of anti-nutritional factors (ANFs) to enhance nutrient digestibility. However, eliminating ANFs does not necessarily correlate with increased protein and amino acid content. Several processing methods, such as soaking, cooking, and commercial techniques, improve SBM protein digestibility. To sustain feeding qualities, soybeans must undergo heating to remove inherent chemicals that interfere with poultry digestion. However, both under and over-processing can impair meal digestibility. Extrusion heating significantly contributes to protein and starch digestibility while reducing certain ANFs. Thermomechanical and enzyme-assisted procedures reduce heat-resistant proteins more efficiently than extraction methods, producing soy protein concentrate (SPC) and fermentation. These techniques reduce ANFs in SBM, activating digestive enzymes and alleviating digestive tract pressure, leading to decreased endogenous protein deficits. Exogenous enzyme supplementation is a biotechnological approach for enhancing the nutritional content of SBM and certain other protein-rich products. However, different processing methods not only affect protein digestibility but also impact poultry production, gastrointestinal health, and the environment due to higher nitrogen excrement. Ammonia (NH <jats:sub>3</jats:sub> ) emissions are a significant environmental concern in chicken farming, resulting from uric acid production during protein consumption. It has a negative impact on the environment and the health of birds/humans. This review investigates the impact of several processing techniques on the digestibility of SBM protein and the reduction of N <jats:sub>2</jats:sub> regarding one health concept. Future research should focus on identifying optimal processing methods maximizing protein digestibility while minimizing environmental nitrogen impacts. </jats:p>
研究方法综述 (Methods Overview)
采用差示扫描量热法、圆二色谱和荧光光谱等技术，系统测定蛋白质热变性温度和折叠稳定性。通过突变体分析探讨关键氨基酸残基的作用。
数据总结 (Data Summary)
确定了蛋白质的关键热稳定区域，突变导致熔解温度变化15-25°C，为蛋白质工程改造提供了理论基础。
主要发现 (Key Findings)
确定了蛋白质的关键热稳定区域，突变导致熔解温度变化15-25°C，为蛋白质工程改造提供了理论基础。
结论 (Conclusions)
热稳定性机制研究为改良蛋白质性能提供了重要参考。
实践意义 (Practical Significance)
对工业酶开发和蛋白质药物设计具有指导意义。