为了保证速冻水饺的冻藏品质，掌握冻藏环境对品质影响的规律，该试验以速冻水饺皮为目标，排除饺馅的干扰，重点研究了冻藏期间温度的波动，时间的推移以及包装方式等对其理化特性、质构特性、感官特性以及微观结构等的影响。结果表明：随着冻藏时间的延长，速冻水饺皮糊化度降低，水分、直链淀粉、醇溶蛋白以及麦谷蛋白含量均呈现下降趋势，面筋蛋白显微网络结构弱化，但质构、感官特性变化不显著。采用透气性、阻湿性较好的 PE 塑料薄膜包装可以较好的保持速冻水饺皮的品质。冻藏期间的温度波动显著降低速冻水饺皮的外观品质和食用品质。该研究为改善速冻食品的贮藏环境提供了理论依据。%The quick-frozen dumpling is one of the most common frozen foods in China. It is important to understand the quality variation of dumpling after frozen storage. The objective of this research was to study the effect of different packaging methods (packed, unpacked), storage time (0-180 days), and thaw-freeze cycles (one cycle means that it is frozen for 2 days and then followed by thaw for 2 days) on the quality of quick-frozen dumpling skin. Physicochemical properties, texture profile analysis (TPA), sensory evaluation (evaluated by a trained analytical panel), and scanning electron microscope (SEM) analysis were performed for both fresh and frozen storage dumpling skins in this study. In particular, the physicochemical properties assessed include whiteness (CIE L* values), water lose ratio, freeze-cracking rate, amylase and protein content, gelatinization degree, crystallinity and best cooking time. The results showed that frozen storage at all regimes had a significant effect on all quality parameters. The data from frozen storage time experiments (-18℃for 0, 30, 60, 90, 120, 150 and 180 days) showed that the longer the frozen storage time, the higher the decreased quick-frozen dumpling skin quality. All the samples was packed with PE-plastic film during frozen storage. The quick-frozen dumpling skin displayed low gelatinization degree compared with fresh samples, declining in contents of amylose, glutelin, and prolamin when storage time was increased. Water lose ratio was increased with increasing storage period. Microstructure measurements showed that the appearance of irregular hole and observed damage on gluten cross-linking may be caused by the ice crystallization during frozen storage. However, freeze-cracking rate and degree of crystallinity of quick-frozen dumpling skin were found similar to those of fresh samples. No significant changes in hardness, springiness, gumminess, chewiness, and sensory attributes were observed during 180 days study period. With increased number of thaw-freeze cycles, the network structure of wheat protein was destroyed gradually and the water lose was significantly increased. Temperature fluctuations during frozen storage significantly reduced the appearance quality and eating quality of quick-frozen dumpling skins. For this reason, the environment temperature should be kept constantly during frozen storage. After three times of thaw-freeze cycles, packaging in PE-plastic film significantly improved the storage stability of quick-frozen dumpling skin compared to the unpackaged one. PE-packed quick-frozen dumpling skin and fresh samples had no significant difference in water lose ratio, degree of crystallinity and sensory evaluation score. The best texture qualities such as hardness, springiness, chewiness were observed in PE-packed dumpling skin instead of fresh samples. However, the unpacked skin’s quality was declined significantly after three thaw-freeze cycles, mainly attributed to the damage on the gluten cross-linking. Therefore, our studies suggested that consistent storage temperature and packaging in PE-plastic film should be adopted during frozen storage for extending the shelf-life of dumpling food.
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