Scientists at the Department of Postharvest Science of The Volcani Center (Israel) studied the role of exogenous ethylene and the potential of 1-MCP in reducing rachis browning in table grapes stored up to 4 weeks.
The study revealed significant differences in respiration between grape varieties tested ('Thompson Seedless', 'Mystery', and '3003' line), with significant effects of ethylene and 1-methylcyclopropane (1-MCP) on rachis browning. Results showed that 1-MCP delayed rachis browning in the three table-grape varieties whereas ethylene tended to enhance it.
Respiration was reduced in 1-MCP-treated-rachis and ethylene production was reduced in one of the varieties. Berry respiration and ethylene production were not affected by the treatments. Interestingly, respiration and ethylene production in rachis of 'Thompson Seedless' were much lower than in the other two tested varieties.
Auto-fluorescence analysis showed that 1-MCP enhanced and ethylene decreased chlorophyll fluorescence. Significant differences were observed in auto-fluorescence properties between treated rachis and untreated ones, the differences resulted consistent with the lower accumulation of flavonoids in the former. Berry auto-fluorescence was also affected by the treatments: ethylene enhanced auto-fluorescence associated with flavonoids in the two green varieties and 1-MCP reduced it in the black variety.
Although it was shown that 1-MCP reduces rachis browning, scientists conclude that the present results open the way for new studies on the role of ethylene in specific tissues of nonclimacteric fruits, and on development of technologies that may reduce the damage involved.
Study is available on line since May 15th 2015 at:
http://www.sciencedirect.com/science/article/pii/S0925521415300016
Source: L. Li, T. Kaplunov, Y. Zutahy, A. Daus, R. Porat, A. Lichter, 'The effects of 1-methylcyclopropane and ethylene on postharvest rachis browning in table grapes', September 2015, Postharvest Biology and Technology, Vol. 107, pages 16–22.
Contacts:
Lichter A.
Department of Postharvest Science, ARO, The Volcani Center,
POB 6, Bet Dagan 50250, Israel
Email: [email protected]
