采前喷钙对黄瓜采后冷藏品质的影响

Effect of Preharvest Calcium Chloride Sprays on the Quality of Postharvest Cucumber Fruits during Cold Storage

冷害是限制黄瓜低温贮藏和运输的主要因素,以黄瓜品种‘露地二号’为试材,对黄瓜叶面进行采前喷施Ca Cl2,以增加黄瓜的耐冷性,研究采前喷钙对黄瓜采后冷藏(4±0.5)℃品质的影响,为春冬两季黄瓜的长途运输和贮藏提供参考。结果表明,冷藏期间各处理冷害指数、丙二醛含量、相对电导率、脯氨酸含量冷藏期间均上升;硬度降低,色泽变暗,可溶固形物含量和主要香气物质相对含量均减少。冷藏结束时,0.75%、1%Ca Cl2处理黄瓜的冷害指数最小为0.3,而且丙二醛含量和相对电导率均显著低于对照(P<0.05);钙处理黄瓜的硬度均比对照大,Ca Cl2质量分数越大硬度越大。0.75%和1%Ca Cl2处理黄瓜含有更多的可溶性固形物,脯氨酸生成量也较多,主要的香气物质相对含量也较大,并且在贮藏期间色泽保持均比对照好。综合考虑,最终确定0.75%Ca Cl2处理为黄瓜喷钙的最佳质量分数,能较好地维持黄瓜采后品质,将冷害症状出现延迟了4 d。

Chilling injury（CI） is the main factor limiting cucumber storage at low temperature. The goal of this research was to use pre-harvest calcium applications to delay CI of ＂Ludi No.2＂ cucumber during cold storage at（4 ± 0.5） ℃, aiming to provide reference data for cucumber transportation in early spring or winter. The results showed that chilling injury index, malonaldehyde（MDA） content, relative conductivity, and free proline increased whereas firmness, soluble solids, color and major volatiles of cucumber fruits decreased during cold storage. At the end of storage, calcium chloride treatment at 0.75% and 1% showed the lowest CI index of 0.3. MDA content and relative conductivity of cucumbers treated with calcium chloride at 0.75% and 1%（m/m） were significantly reduced as compared with those of controls stored at 4 ℃（P〈0.05）. Cucumbers sprayed with Ca Cl2 were firmer than controls. The more calcium was sprayed, the higher the firmness was. Cucumbers sprayed with Ca Cl2 at 0.75% and 1% contained higher levels of soluble solid content（SSC）, free prolinet and major volatiles contents, and were greener and less sensitive to low temperature than controls. It is concluded that the overall quality of cucumbers treated with calcium was better than that of controls. Taking all into account, 0.75% is the optimal concentration. Also, cucumbers sprayed with calcium at 0.75% could delay the occurrence of CI by up to 4 days and maintained its quality better during cold storage.