Changes in pectin methyl esterase activity with different packaging materials and stages of fruit harvesting during cold storage of pear cv. Punjab beauty

Abstract

Pear cv. Punjab Beauty has become quite popular in Punjab. Excessive softening during cold storage leading to low shelf life is the major factor limiting its wider adoption. Studies were, therefore, conducted to determine the firmness and pectin methyl esterase (PME) activity at 4 harvest dates (2nd, 3rd and 4th week of July, and 1st week of August). Various packaging materials i.e. corrugated fiber board boxes and crates with high and low density polyethylene liners, corrugated fiber board boxes, crates and wooden boxes were also evaluated for their role in extending the shelf life of fruits. The enzyme activity and fruit firmness was evaluated periodically after 30, 45, 60 and 75 days of storage at 0-1°C and 90-95 % RH. The firmness of the fruits decreased with the increase in storage intervals but the enzyme activity increased with the storage period up to 60 days and declined thereafter. Ripening-related changes in all the harvests were characterized mainly by an increase in the solubilization of pectin with a concomitant decrease in the degree of firmness. There was a continuous increase in enzyme activity with the advancement in harvesting dates and then fell sharply in the advanced ripening stages. Highest pectin methyl esterase activity was in fruits packed in crates followed by wooden boxes and corrugated fiber board boxes while the lowest was recorded in fruits packed in corrugated fiber board boxes with high density polyethylene liners. Therefore, high density polyethylene lined CFB boxes proved to be most effective in preventing the loss in firmness.

Effect of different packaging films on shelf life and quality of peach under super and ordinary market conditions

“…The lowering of PME activity in shrink film packed fruit may be due to slower respiratory activity occurring inside the package due to creation of modified atmospheric conditions (Sen et al 2012;Giacalone and Chiabrando 2013). Kaur et al (2012) reported lower PME activity during storage in pear fruits packed in polymeric film. …”

Changes of Pectin Substances Content During the Pear Fruits Storage With Antioxidant Compositions Treatment

“…The dynamics of pectic substances changes during the pear fruit storage was studied by Kaur, K., Dhillon, W.S., & Mahajan, B.V. [1]. At the same time, various packaging materials were used to store pear fruit.…”

“…Fruit are especially rich in them. Pectic substances form part of the fruit cell walls, participate in the regulation of the water regime of tissues, regulate transpiration [1]. Their transformation during ripening and storage, the transition from an insoluble form to a soluble one and reverse determines the consistency of fruit pulp.…”

Changes in the carbohydrate complex of fruits during storage with treatment wits antioxidant compositions

“…Протягом зберігання пектинові речовини, разом з геміцелюлозами та целюлозою піддаються значним кількісним змінам у бік зниження. Продукти розпаду полісахаридів приймають участь у обміні речовин та можуть виступати субстратами дихання [9,10,11,12].…”