ABSTRACT

Pear fruits are climacteric in nature and remain biologically active due to continuous respiration, transpiration, and other biochemical processes even after harvest. Under ambient conditions of north-western India, pear fruits have a short shelf life. An experiment was conducted to enhance the shelf life of pear fruits cv. Punjab Beauty using preharvest sprays of putrescine (PUT) @ 1 mM, 2 mM & 3 mM. Mature fruits from PUT treated and control plants were harvested and stored at ambient conditions (32 ± 2 ℃, 78 ± 5% RH). Periodical observations for various physicochemical parameters and enzymatic activities were taken on 0, 3, 6, 9, 12 and 15 days after ambient storage. As compared to control, 2 and 3 mM PUT treatments resulted into a reduction in weight loss (WL), spoilage along with retention of higher firmness, soluble solid content (SSC), titratable acidity (TA), and starch content in stored pear fruits. During storage, these treatments had also reduced the fruit softening by reducing the activities of cell wall degrading enzymes like pectin methylesterase (PME) and cellulase. So, it could be inferred that PUT treatment of 2 mM & 3 mM was effective to enhance the shelf life of pear fruits at ambient conditions with acceptable quality.

摘要

梨果实本质上是更年期的，即使在收获后，由于持续的呼吸作用、蒸腾作用和其他生化过程，它仍保持生物活性。在印度西北部的环境条件下，梨果实的保质期很短。进行了一项实验以提高梨果实 cv 的保质期。旁遮普美容使用腐胺 (PUT) @ 1 mM、2 mM 和 3 mM 的收获前喷雾剂。在环境条件（32 ± 2 ℃，78 ± 5% RH）下收获和储存来自 PUT 处理和对照植物的成熟果实。在环境储存后 0、3、6、9、12 和 15 天定期观察各种物理化学参数和酶活性。与对照相比，2 和 3 mM PUT 处理导致重量损失 (WL​​)、腐败以及保持较高的硬度、可溶性固体含量 (SSC)、贮藏梨果实中的可滴定酸度（TA）和淀粉含量。在贮藏期间，这些处理还通过降低果胶甲酯酶 (PME) 和纤维素酶等细胞壁降解酶的活性来减少果实软化。因此，可以推断，2 mM 和 3 mM 的 PUT 处理可有效延长梨果实在环境条件下的保质期，并具有可接受的质量。