‘强特勒’脱青皮鲜核桃冻藏过程中品质的变化情况

Changes in quality of peeled fresh Chandler walnut during freezing storage

旨在为实现鲜食核桃周年供应提供技术支持,以‘强特勒’核桃为研究对象,探究脱青皮鲜核桃在冻藏过程(-10℃,10个月)中感官品质、色差、营养成分、油脂理化指标(过氧化值和酸值)等品质的变化。结果表明:‘强特勒’脱青皮鲜核桃在-10℃条件下冻藏10个月后,其种皮颜色、种皮分离度、种仁颜色、香气、风味的品质级别均下降,即感官品质下降;种皮和种仁的色差随着冻藏时间的延长不断增大,且种皮色差的变化程度较种仁的大;蛋白质、脂肪和可溶性糖含量下降;脂肪酸组成无变化,但不饱和脂肪酸相对含量上升,饱和脂肪酸相对含量下降;氨基酸组成和矿物元素种类均无变化;油脂过氧化值和酸值均呈上升趋势,但均符合LY/T3004.8—2018《核桃第8部分:核桃坚果质量及检测》的限量规定。综上,‘强特勒’脱青皮鲜核桃在冻藏过程中品质变化不大,可实现周年供应。

Aiming to provide technical support for the realization of annual supply of fresh walnut,Chandler walnut was used as the research object to investigate the changes of sensory quality,colour difference,nutrient content of the walnut,and physicochemical indexes(peroxide value and acid value)of the oil during the freezing storage of peeled fresh walnut at-10℃for 10 months.The results showed that the quality levels of seed coat colour,seed coat separation,seed kernel colour,aroma and flavour of peeled fresh Chandler walnut declined afer 10 months of storage at-10℃,indicating the sensory quality decreased.The colour difference between seed coat and seed kernel increased with the prolongation of frezing storage time,and the degree of colour difference of seed coat was greater than that of seed kernel;the relative contents of protein,fat and soluble sugar decreased;the composition of fatty acid did not change,the content of unsaturated fatty acid increased,while the relative content of saturated fatty acid decreased.There was no change in the types of amino acids and mineral elements;both the peroxide value and acid value of the oil increased,but met with the limit of LY/T 3004.8-2018 Walnutspart 8:Quality and inspection of walnut nuts.To sum up,the quality of peeled fresh Chandler walnut has few changes during freezing storage,so it can be supplied all year round.