Hexanal formulation reduces rachis browning and postharvest losses in table grapes cv. ‘Flame Seedless’

Abstract

Rachis browning is one of the major storage problems which reduces the quality and marketability of table grapes. Investigations were carried out to verify the potential of pre-harvest hexanal formulation ‘Enhanced Freshness Formulation’ (US Patent # 6514914: # 7198811 B2) (EFF @ 1.0%, 1.5% & 2.0% v/v) treatment to delay the rachis browning and maintaining the quality of grapes (Vitis vinifera L.) cv. ‘Flame Seedless’ during 2017 and 2018. Grape clusters from treated vines were harvested at the commercial maturity, and then stored at 0–2 °C & 90–95% RH for 60 days. Evaluation of physico-chemical attributes and other fruit quality parameters were made at 0 day (before treatment) and at 15, 30, 45 and 60 days of storage. Hexanal formulation @ 2.0% suppressed the activity of pectin methyl esterase (PME) and browning related enzyme polyphenol oxidase (PPO) with maintained rachis freshness and reduced the rate of cluster weight loss & berry shattering. Hexanal formulation treated bunches retained total soluble solids and titratable acids at higher level during the storage period. In conclusion, the pre-harvest spray of hexanal formulation @ 2.0% proved to be an effective means for delaying the rachis browning and maintaining the quality of Flame Seedless table grapes under prolonged cold storage.