Meerasri Jitrawadee, Chollakup Rungsima, Sothornvit Rungsinee
Department of Food Engineering, Faculty of Engineering at Kamphaengsaen, Kasetsart University Kamphaengsaen Campus Nakhonpathom 73140 Thailand
Kasetsart Agricultural and Agro-Industry Product Improvement Institute, Kasetsart University Bangkok 10900 Thailand.
RSC Adv. 2022 Oct 5;12(44):28441-28450. doi: 10.1039/d2ra05220b. eCollection 2022 Oct 4.
Sericin is a natural protein and a by-product obtained from silk processing. To enhance the antioxidant properties of sericin, sericin hydrolysis was studied. The solvent effects (distilled water, citric acid and hydrochloric acid) and hydrolysis methods (heat treatment (water bath) and mild ultrasonic treatment at 20%, 40% or 60% amplitude) were investigated on the properties of sericin hydrolysate (SH). Furthermore, solvent effects (distilled water and 15% ethanol) were examined for the properties of the sericin films incorporated with selected SH. The SH samples from acid hydrolysis and the ultrasonic method had a darkened visual appearance. However, the degree of hydrolysis and antioxidant activity of SH increased with ultrasonic-assisted acid hydrolysis. The molecular weight (MW) of sericin was notably reduced. As expected, hydrochloric acid hydrolysis resulted in a lower MW for the SH than from citric acid. Thus, SH from hydrochloric acid and 20% amplitude in the ultrasonic method were selected to produce a sericin film. As revealed, using distilled water as a general solvent provided films with lower solubility and water vapor permeability but higher tensile strength. Furthermore, the addition of SH enhanced the antioxidant properties of its hydrolysate as a novel protein packaging film material for various applications.
丝胶蛋白是一种天然蛋白质，是丝绸加工过程中获得的副产品。为了增强丝胶蛋白的抗氧化性能，对丝胶蛋白水解进行了研究。考察了溶剂效应（蒸馏水、柠檬酸和盐酸）和水解方法（热处理（水浴）以及20%、40%或60%振幅的温和超声处理）对丝胶蛋白水解产物（SH）性能的影响。此外，还研究了溶剂效应（蒸馏水和15%乙醇）对掺入所选SH的丝胶蛋白膜性能的影响。酸水解和超声法制备的SH样品外观呈深色。然而，超声辅助酸水解使SH的水解程度和抗氧化活性增加。丝胶蛋白的分子量（MW）显著降低。正如预期的那样，盐酸水解得到的SH的MW低于柠檬酸水解得到的SH。因此，选择盐酸水解且超声处理振幅为20%的SH来制备丝胶蛋白膜。结果表明，使用蒸馏水作为通用溶剂可使膜具有较低的溶解性和水蒸气透过率，但具有较高的拉伸强度。此外，添加SH增强了其水解产物作为一种新型蛋白质包装薄膜材料在各种应用中的抗氧化性能。
