Managing ‘Bartlett’ pear fruit ripening with 1-methylcyclopropene reapplication during cold storage

Authors: ARGENTA, LUIZ - Epagri; Mattheis, James; Fan, Xuetong; AMARANTE, CASSANDRO - University Of Santa Catarina

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/2015
Publication Date: 3/1/2016
Citation: Argenta, L.C., Mattheis, J.P., Fan, X., Amarante, C.V. 2016. Managing ‘Bartlett’ pear fruit ripening with 1-methylcyclopropene reapplication during cold storage. Postharvest Biology and Technology. 113:125-130.

Interpretive Summary: Bartlett pears are a popular fruit that is typically eaten when soft and ripe. Slowing ripening of harvested pears allows fruit to be available for months longer in retail stores. Extending fruit storage life also can increase the risk of disorders that can cause discoloration of peel and/or flesh tissues. Postharvest technologies that slow ripening and minimize disorder development can be difficult to implement successfully for both fruit quality and appearance management. A technology that utilizes an inhibitor of fruit ripening works well for both purposes, however, softening can be unpredictably delayed limiting development of optimal eating quality. Scientists at the USDA, ARS Tree Fruit Research Laboratory evaluated techniques to maximize the effects of the ripening inhibitor while allowing for predictable ripening. Results of these studies indicated repeated application of the inhibitor instead of a single large dose at harvest provides a means to slow ripening while allowing for softening after short or long periods in cold storage. The results suggest a commercial strategy to enhance postharvest management of Bartlett pears that extends fruit storage life while allowing optimal softening once fruit have moved through the marketing chain.

Technical Abstract: Repeated low-dose 1-MCP-applications were evaluated during cold storage of ‘Bartlett’ pear fruit to overcome long-term ripening inhibition of a high dose 1-MCP treatment at harvest. Fruit were exposed to 1-MCP at 0, 0.42, 4.2 or 42 umol m-3 at harvest in year one, and to 0, 0.42 or 42 umol m-3 in year two, and then stored in air at 0.5oC. In year two, fruit exposed to 1-MCP at 0.42 umol m-3 at harvest were retreated during cold storage once (after 38 days) or twice (after 38 and 68 days), when ethylene production in samples removed from cold storage exceeded 0.05 umol kg-1 h-1 within 7 days at 20oC. 1-MCP was re-applied once at 0.42 or 4.2 umol m-3 or twice at 0.42 or 4.2 then 42 umol m-3. In year one, fruit treatment at harvest with 4.2 or 42 umol m-3 1-MCP provided similar ripening delay during 120 days in storage followed by 7 days at 20oC, while fruit treated with 0.42 umol m-3 1-MCP was not different from the control. In year two, fruit treated at harvest with 0.42 umol m-3 1-MCP and retreated with 0.42 umol m-3 (when ethylene production was already high) did not delay subsequent fruit ripening. Fruit treated at harvest with 42 umol m-3 1-MCP or with 0.42 umol m-3 at harvest and then +4.2+42, had similar peel yellow color, TA and SSC, but higher firmness after 180 days storage, compared to control fruit after 60 days storage. Therefore, a low dose application of 1-MCP at harvest followed by reapplication with higher doses based on fruit ethylene production capacity during cold storage can extend ‘Bartlett’ pear storage life while allowing ripening to occur after mid-term storage. The efficiency of this procedure will depend on timing and 1-MCP reapplication concentration.