为探讨不同状态鲜核桃贮藏期间种仁的品质变化差异,以‘清香’鲜核桃为材料,测定3种状态鲜核桃(带壳坚果、整仁和碎仁)在(0±0.5) ℃冷藏期间的品质指标动态变化。结果表明,贮藏期间各状态鲜核桃的发霉指数随着贮藏时间的延长而升高,整仁和碎仁的发霉指数显著降低;脂肪酸组分无显著变化,不饱和脂肪酸含量下降,饱和脂肪酸含量上升;3种状态的粗脂肪含量总体下降,以碎仁的粗脂肪平均含量最高,其在贮藏30 d期间多酚氧化酶活性较低,过氧化物酶活性显著升高,之后其可溶性糖和可溶性蛋白质含量却低于坚果和整仁;酸价和过氧化值均符合林业标准。总体上看,贮藏过程中整仁保持了较好的品质,碎仁油脂品质相对稳定,但因其破碎程度高,营养成分含量损失较多较早失去商品价值,而坚果在保持较高的营养方面具有更大潜力。
关键词：
鲜核桃; 不同状态; 品质; 发霉; 冷藏
To explore the physiological and quality changes of fresh walnuts in different states during storage, ‘Qingxiang’ fresh walnuts were stored at (0±0.5) ℃ in three different states, including in-shell nuts, whole kernels, and crushed kernels, then the dynamic changes of physiological and quality indicators were measured.Results showed that the mould index of fresh walnuts in different states increased with the storage time, while those of whole and crushed kernels decreased significantly.There was no significant change in the composition of fatty acids, and the saturated fatty acids content decreased while the unsaturated fatty acids content increased.The crude fat content declined overall, with the average content being the highest in the crushed kernels.During 30 days of storage, the polyphenol oxidase activity was lower while the peroxidase activity significantly increased in crushed kernels compared with other states, but thereafter the contents of soluble sugar and soluble protein were lower than those of nuts and whole kernels.The acid value and peroxide value both meet the forestry standards.Overall, the whole kernels maintained better quality and the oil quality was relatively stable for the crushed kernels, while the nuts kept the higher nutritional quality and oleic acid content with the greater potential for application in maintaining oxidative stability during storage.However, due to the higher degree of fragmentation and nutritional loss, the crushed kernels lost commercial value earlier.
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