Aminlari M, Shekarforoush S S, Gheisari H R, Golestan L
Department of Biochemistry , School of Veterinary Medicine, Shiraz Univ., Shiraz 71345, Iran.
J Food Sci. 2009 Apr;74(3):C221-6. doi: 10.1111/j.1750-3841.2009.01087.x.
The objective of this study was to study the effect of actinidin, a sulfhydryl protease from kiwi fruit, on the protein solubility (nitrogen solubility index [NSI]), water holding capacity (WHC), texture, and SDS-PAGE pattern of beef and to evaluate the effect of pretreatment of beef with actinidin on the quality attributes of a sausage product. Actinidin was partially purified by precipitation with ammonium sulfate, followed by DEAE-Sephadex column chromatography. Actinidin significantly (P < 0.05) increased NSI and WHC of beef; the highest NSI and WHC (approximately 20% and 8% increase, respectively) was observed when beef was incubated with 0.9 unit enzyme/g beef. Texture analysis indicated increased tenderization (10% decrease in shear force) when slices of cattle beef were treated with actinidin at 37 degrees C for 2 h. SDS-PAGE results indicated appearance of several low molecular weight bands (<10 kDa) after treating beef with different levels of actinidin for 30 or 60 min. Slight changes in protein band in the range of 100 to 120 kDa and 13 to 25 kDa were also observed. Use of actinidin-tenderized beef significantly improved emulsion stability, texture, and organoleptic properties of the sausage product.
本研究的目的是研究奇异果中的巯基蛋白酶——猕猴桃蛋白酶对牛肉的蛋白质溶解度（氮溶解度指数[NSI]）、持水能力（WHC）、质地和SDS - PAGE图谱的影响，并评估用猕猴桃蛋白酶预处理牛肉对香肠产品品质特性的影响。通过硫酸铵沉淀，然后进行DEAE - 葡聚糖凝胶柱色谱法对猕猴桃蛋白酶进行部分纯化。猕猴桃蛋白酶显著（P < 0.05）提高了牛肉的NSI和WHC；当牛肉与0.9单位酶/克牛肉一起孵育时，观察到最高的NSI和WHC（分别增加约20%和8%）。质地分析表明，当牛牛肉片在37℃下用猕猴桃蛋白酶处理2小时时，嫩度增加（剪切力降低10%）。SDS - PAGE结果表明，用不同水平的猕猴桃蛋白酶处理牛肉30或60分钟后，出现了几条低分子量条带（<10 kDa）。在100至120 kDa和13至25 kDa范围内的蛋白质条带也观察到轻微变化。使用经猕猴桃蛋白酶嫩化的牛肉显著改善了香肠产品的乳化稳定性、质地和感官特性。
