Applications of Proteolytic Enzymes from Kiwifruit on Quality Improvements of Meat Foods in Foodservice

The purpose of this study was to evaluate kiwifruit as a tenderizer by its effects in improving the quality of various beef parts. Basic data are provided for development of standard recipes for convenient cooking in foodservice. The optimum temperature of the crude proteolytic enzymes in the kiwifruit was determined to be $65^{\circ}C$. The substrate specificity of the enzymes was higher in beef than in pork, chicken, or duck. The enzymes had their greatest effects on chuck and rib parts, and had lower effects on loin, breast, and round parts, in that order. As the amount of kiwifruit extract increased, the moisture content of the cooked beef also increased. The addition of 10% kiwifruit improved the sensory quality of the cooked beef. In particular, the texture scores of cooked beef samples treated with 10% and 15% kiwifruit extract were significantly higher than the other samples (p<0.001), and juiciness and overall acceptability scores were also highest. In summary, 10% kiwifruit extract is deemed an appropriate addition to improve.