碱性pH值提取对大豆油脂体稳定性及消化特性的影响

为了解碱性pH值（8.0～11.0）条件下从大豆中提取油脂体（soybean oil body,SOB）所形成天然乳液的稳定性及其在胃肠道中的消化特性，通过SOB的基本组成、粒径、Zeta电位和流变学等研究其稳定性，并利用脂肪酸释放量和微观结构探究其消化特性。结果表明，随着提取pH值的升高，SOB水分和蛋白质含量降低，脂质含量不同程度增加，SOB粒径由（471.57±8.53）nm下降至（424.77±12.21）nm；此外，SOB氧化稳定性表现出相似的趋势，氢过氧化值随着pH值的升高而降低，硫代巴比妥酸反应物值随着时间的延长而增大；表观黏度随剪切速率的增加而降低，SOB乳液呈剪切稀化，所有样品的G’都大于G”，随着提取pH值的升高，可以显著提高SOB游离脂肪酸释放率（P<0.05）。本研究为高稳定性天然SOB的广泛应用提供一定理论支撑。

Effect of Alkaline pH Extraction on the Stability and Digestive Properties of Soybean Oil Bodies

The purpose of this study was to understand the stability of natural emulsions formed from soybean oil bodies (SOB) extracted at alkaline pH (8.0–11.0) and their digestive properties in the gastrointestinal tract. The stability of SOB was evaluated in terms of its basic composition, particle size, zeta potential and rheology, and the digestive properties were evaluated in terms of fatty acid release from SOB and the microstructure of SOB. The results showed that with an increase in extraction pH, the water and protein contents of SOB decreased and the particle size decreased from (471.57 ± 8.53) nm to (424.77 ± 12.21) nm, while the lipid content increased. In addition, the oxidative stability of SOB showed a similar trend. Specifically, the peroxide value (POV) decreased with increasing extraction pH and the thiobarbituric acid reactive substances (TBARS) value increased with an increase in storage time. The apparent viscosity decreased with increasing shear rate. SOB emulsions showed shear thinning behavior with G’ being greater than G” for all samples, and the release percentage of free fatty acids from SOB significantly increased with increasing extraction pH (P < 0.05). This study provides theoretical support for the wide application of highly stable natural SOB.