采后热空气处理对嘎拉苹果质地的影响及其作用机理

Effect and mechanism of hot air treatment on the fruit texture of Gala apple cultivar

应用整果穿刺(Puncture)和质地多面分析(TPA)的方法研究采后热处理(38℃4d)对嘎拉苹果质地的影响,同时研究热处理对果实不同溶解性果胶含量的影响,建立不同溶解性果胶含量与果肉硬度之间的相关性。研究发现,2种测试方法都能较好的反映苹果质地特点;嘎拉苹果的果肉硬度与水溶性果胶含量呈极显著的负相关,与碳酸钠溶性果胶呈极显著的正相关,而与CDTA(环乙二胺四乙酸)溶性果胶、硫酸溶性果胶、总果胶含量没有显著的相关性。采后热处理能显著提高贮藏后期嘎拉苹果的果皮和果肉硬度、果肉的凝聚性、咀嚼性和回复性,这主要是由于热处理显著减少了嘎拉苹果水溶性果胶含量的上升,并维持较高的碳酸钠溶性果胶,但对CDTA溶性果胶、硫酸溶性果胶和总果胶没有显著的影响。

In order to investigate the effect of heat treatment （38 ℃ 4 d） on the fruit texture of Gala apples, the puncture test and texture profile analysis （TPA） was used. At the same time, the effects of heat treatment on the different soluble pectin were measured, and the relationships between hardness and pectin were established. It was found that two test methods could express the texture characteristics of apples. Fruit hardness was significantly negatively correlated with the water soluble pectin content, and positively correlated with the sodium carbonate soluble pectin. However, fruit hardness was not significantly correlated with CDTA （trans -agclohexylene- 1,2-diamine-N, N, N′, N ′-tetraacetate） soluble pectin, sulfuric acid soluble pectin and total pectin. At the later storage period, heat-treated apples maintained higher skin hardness, flesh hardness, cohesiveness, chewing character and resilience. This result was mainly due to the significant reduction of the content of water soluble pectin, and maintained high level of carbonate soluble pectin in heat-treated apples. It was also observed that heat treatment did not significantly affect the content of CDTA soluble pectin, sulfuric acid soluble pectin and total pectin.