Effect of Diphenylamine on Core Browning, Antioxidant Metabolites, Fruit Firmness and Enzyme's Activity in Pear cv. Yali

An experiment was carried out to observe the effects of diphenylamine (DPA) on core browning, antioxidant metabolites, fruit firmness and pectin methyl esterase activity of YaLi pear in department of horticulture, Punjab agricultural university, Ludhiana. Pear fruits were harvested on July 1^st at proper maturity and treated with diphenylamine (DPA) 500, 1000 and 1500 ppm. Fruits were stored in cold storage at 1–3^oC temperature with 90–95% RH and were analyzed after 30, 45 and 60 days of storage. Core browning, malanodialdehyde and pectin methyl esterase activity increased, however, ascorbic acid content phenols content and fruit firmness decreased with the increase in the storage period. The effectiveness of higher concentration of DPA was more in maintaining higher level of malanodialdehyde, phenols, fruit firmness and pectin methyl esterase activity. The ascorbic acid content was recorded more with DPA (1000 ppm) and core browning were observed to be low with highest DPA concentration.