Articles
Peroxidase activity of the bagged fruits of Forest Beauty and Dilafruz pears in the climatic conditions of Tashkent region
Article number
1364_12
Pages
95 – 100
Language
English
Abstract
The firmness and shelf life properties of pear fruits are related to the intensity of peroxidase activity and consequent formation of the monolignol oxidation and polymerization of lignin in the secondary cell wall.
The influence of preharvest paper bagging (PHPB) practice on the shelf-life of pear fruits was identified in our previous research devoted to organic fruit production.
After, it was decided to analyze the peroxidase activity of the bagged fruits of pear cultivars Forest Beauty and Dilafruz. The pear fruits were covered with white, orange and black double layered paper bags (DLPB) 40-50 days after full blossoming in the orchard situated in Tashkent region.
The unripe fruit samples were collected and the activity of peroxidases was assayed using the tetramethylbenzidine (TMB) substrate reaction.
The optic densities of reaction batch samples were measured at a wavelength of 450/630 nm.
The highest absorbance unit (AU) of peroxidase activity was observed in the fruits of Forest Beauty covered with orange (2.333 AU) DLPB, and Dilafruz, covered with white (2.537 AU), orange (2.541 AU) and black (2.501 AU) DLPB. The lowest AU was observed in the fruits of Forest Beauty covered with white (1.368 AU) and black (1.160 AU) DLPB, and non-bagged fruits of Dilafruz (2.331 AU). The cessation of the growth of the highly lignified stone cell clusters as the consequence of high peroxidase activity leads to the compensational enlargement of interstitial cells.
The significant enlargement of interstitial cells provided to fruits softness.
Thus, a negative correlation was observed between the peroxidase activity and fruit firmness within a cultivar, while, a positive correlation was revealed within all studied samples.
The results confirm that the PHPB practice enhanced the activity of peroxidases and reduced the firmness in fruits of Dilafruz. However, the high values of firmness were observed only in the fruits of Forest Beauty covered with white and black DLPB. The reason of various effect of PHPB practice is due to the different biological characteristics of pear cultivars.
The influence of preharvest paper bagging (PHPB) practice on the shelf-life of pear fruits was identified in our previous research devoted to organic fruit production.
After, it was decided to analyze the peroxidase activity of the bagged fruits of pear cultivars Forest Beauty and Dilafruz. The pear fruits were covered with white, orange and black double layered paper bags (DLPB) 40-50 days after full blossoming in the orchard situated in Tashkent region.
The unripe fruit samples were collected and the activity of peroxidases was assayed using the tetramethylbenzidine (TMB) substrate reaction.
The optic densities of reaction batch samples were measured at a wavelength of 450/630 nm.
The highest absorbance unit (AU) of peroxidase activity was observed in the fruits of Forest Beauty covered with orange (2.333 AU) DLPB, and Dilafruz, covered with white (2.537 AU), orange (2.541 AU) and black (2.501 AU) DLPB. The lowest AU was observed in the fruits of Forest Beauty covered with white (1.368 AU) and black (1.160 AU) DLPB, and non-bagged fruits of Dilafruz (2.331 AU). The cessation of the growth of the highly lignified stone cell clusters as the consequence of high peroxidase activity leads to the compensational enlargement of interstitial cells.
The significant enlargement of interstitial cells provided to fruits softness.
Thus, a negative correlation was observed between the peroxidase activity and fruit firmness within a cultivar, while, a positive correlation was revealed within all studied samples.
The results confirm that the PHPB practice enhanced the activity of peroxidases and reduced the firmness in fruits of Dilafruz. However, the high values of firmness were observed only in the fruits of Forest Beauty covered with white and black DLPB. The reason of various effect of PHPB practice is due to the different biological characteristics of pear cultivars.
Authors
A.A. Kayumov, J.A. Gafurov, K. Katsura, Y. Kawabata, T. Ban, Z.S. Ismoilov
Keywords
preharvest paper bagging, firmness, shelf life, lignin, organic fruit production
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