山梨醇提高壳聚糖季铵盐涂膜对蓝莓的保鲜效果

Effect of Plasticizers on the Preservation of Blueberries by Quaternary Ammonium Salt of Chitosan Coating

摘要:

为寻找可以提高壳聚糖季铵盐(quaternary ammonium salt of chitosan，HTCC)涂膜保鲜蓝莓效果的增塑剂，本文分别选取含2%的多元醇增塑剂甘油、山梨醇和聚乙二醇-6000（polyethylene glycol，PEG）的HTCC涂膜液对蓝莓进行涂膜，通过测定果实失重率、硬度、Vc含量、呼吸强度、花青素含量等指标，研究在4 ℃时各涂膜液对蓝莓的保鲜效果。结果表明：添加甘油的涂膜液明显地提高了蓝莓果实的失重率，降低了硬度，与其它组有显著性差异（p<0.05)，因此HTCC涂膜液中不适合添加2%甘油；添加山梨醇的涂膜液在保藏期间可以降低蓝莓的失重率和呼吸强度，减缓花青素和可溶性固形物(total soluble solid，TSS)的变化，与其它组有显著性差异（p<0.05）。其中，在第8 d时，该组蓝莓的失重率和呼吸强度分别为添加PEG处理组的80.71%和80.16%，为CK组的81.25%和75.47%。因此2%山梨醇可以提高HTCC涂膜液的保鲜效果，有利于延长蓝莓的货架期。

Abstract:

In order to search the plasticizers to increase the preservation effects of quaternary ammonium salt of chitosan (HTCC) coating on blueberries, 2% glycerol, sorbitol and polyethylene glycol-6000 (PEG) were added to HTCC coating, respectively. The weight loss rate, hardness, Vc content, respiratory intensity and anthocyanin content of blueberries were detected. The results showed that the coating added with glycerol could increase the weight loss and reduce the hardness of blueberries obviously and had significant difference with other groups (p<0.05). Therefore, 2% glycerol was not suitable for adding to HTCC coating. The coating added with could reduce the weight loss and respiratory intensity of blueberries, and delay the changes of anthocyanin and total soluble solid (TSS), and had significant difference with other groups (p<0.05). At 8 d, the weight loss and respiration intensity of blueberries in the group of sorbitol addition were 80.71% and 80.16%, respectively of the ones of the group processing with the coating adding with PEG , and 81.25% and 75.47% respectively of the ones of CK. Therefore, 2% sorbitol can improve the preservation effect of HTCC, which is conducive to prolonging the shelf life of blueberries.