仙谷米花糖哈败成因及防止措施

Cause and Prevention of Rancidity in Crunchy Rice Candy with Added Spiny Amaranth(Amaranthus spinosus L.) Seeds

野苋菜是我国重要的野生蔬菜资源,由其种子加工而成的仙谷米花糖口感酥脆、天然健康,深受消费者青睐,市场开发潜力大。但仙谷米花糖在贮藏和销售过程中易产生氧化哈败、风味劣变,保质期较短。本实验研究了仙谷米花糖在不同条件下的储藏效果、仙谷油脂的脂肪酸组成及其理化特点。并用气相色谱-质谱联用(gas chromatograph-mass spectrometer,GC-MS)分析仙谷油脂加速氧化前后的成分差异。结果表明:仙谷含油率为6.26%、油脂酸价为2.79 mg/g、皂化值为144.79 mg/g、碘值为87.48 g/100 g;其中亚油酸含量为33.91%、油酸36.05%、棕榈酸15.39%、硬脂酸4.01%、角鲨烯7.03%;仙谷油脂加速氧化后角鲨烯消失,脂肪酸种类增加,醛类、酯、吡嗪、烯烃、苯胺、酚、酮类物质产生,说明角鲨烯是导致仙谷米花糖氧化哈败的主要原因,铝箔真空包装加脱氧剂能有效减缓仙谷米花糖哈败。

Spiny amaranth(Amaranthus spinosus L.) is an important resource of wild vegetable in China. Its seeds have been applied in crunchy rice candy which is a crisp, natural healthy food with a huge marketing potential greatly favored by consumers. However, crunchy rice candy with added spiny amaranth seeds is susceptible to oxidative rancidity, flavor deterioration and shortened shelf life. This experiment investigated the post-storage quality of the crunchy rice candy as well as the fatty acid composition and physiochemical characteristics of spiny amaranth seed oil. In addition, changes in fatty acid composition of spiny amaranth seeds before and after accelerated oxidation were monitored by gas chromatographmass spectrometer(GC-MS). The analytical data showed that the average oil content of spiny amaranth seeds was 6.26%, acid value 2.79 mg/g, saponification value 144.79 mg/g, iodine value 87.48 g/100 g, linoleic acid 33.91%, and the contents of oleic acid, palmitic acid, stearic acid and squalene were 36.05%, 15.39%, 4.01% and 7.03%, respectively. After the accelerated oxidation, squalene disappeared from spiny amaranth seed oil, and more fatty acids were formed as well as small molecule substances such as aldehydes, esters, pyrazines, alkenes, anilines, phenols and ketones. Thus, squalene may be the main cause of rancidity in crunchy rice candy with added spiny amaranth seeds. Aluminum foil vacuum packaging with deoxidizer can effectively ease its rancidity.