热处理及山梨糖醇对生鲜面品质及货架期的影响

Influences of heat treatment and sorbitol at different concentrations on the quality and shelf life of fresh noodles

水分活度是影响生鲜面货架期的关键指标,山梨糖醇作为水分调节剂常被用来降低产品的水分活度。为延长生鲜面的货架期并改善面条品质,以水分活度、水分分布、色泽、蒸煮品质、质构品质、菌落总数等为指标,研究了热处理及添加不同质量分数的山梨糖醇对生鲜面品质及货架期的影响。结果表明:热处理及添加不同质量分数的山梨糖醇可以协同降低生鲜面的水分活度,增加结合水的含量,热处理后面片的总色差降低,且在同一热处理温度下,随着山梨糖醇质量分数的增加总色差也呈降低的趋势;98℃下随着山梨糖醇质量分数的增加生鲜面的蒸煮损失率先增加后降低;在相同的热处理温度下,随着山梨糖醇质量分数的增加,煮后面条的硬度和咀嚼性显著降低,淀粉的糊化特性表明峰值黏度和回生值也呈降低的趋势。此外,热处理和山梨糖醇协同作用延长了生鲜面的货架期,98℃处理且山梨糖醇质量分数为2%的生鲜面常温储藏货架期延长到120 h。

Water activity is a key indicator affecting the shelf life of fresh noodles.As a moisture regulator,sorbitol is commonly used to reduce the water activity of products.The aim of this study was to extend the shelf life and to improve the quality of noodles.In this paper,water activity,water distribution,color,qualities of cooking,textural characteristics and total number of bacterial colonies were used as indicators,effects of heat treatment and sorbitol at different mass fractions on the quality and shelf life of fresh noodles were investigated.The results showed that heat treatment and sorbitol could cooperatively lower the water activity and increase the content of bound water in fresh noodles.The total chromatism of dough sheet decreased after heat treatment,and was also in descending trend as the mass fraction of sorbitol increased at the same heat treatment temperature.At 98℃,as mass fraction of sorbitol increased,the cooking loss rate of the fresh noodles firstly increased,and then decreased.At the same treatment temperature,when the concentration of sorbitol increased,the hardness and chewiness of cooked noodles were significantly reduced,and the peak viscosity and retrogradation values also showed a decreasing trend.In addition,the heat treatment and sorbitol synergistically prolong the shelf life of the fresh noodles.The shelf life of fresh noodles was extended to 120 hours with a sorbitol mass fraction of 2%at the heat treatment temperature of 98℃.