by Bioconservacion March 16th, 2017 0 comments

 

Ethylene handling would allow storage of non-climacteric products at temperatures higher than recommended. A scientific paper recently published (1) quantifies the relationship between ethylene concentration, temperature and post-harvest life of different non-climacteric vegetables (pak choi, broccoli, mint and green beans).

The results show that an efficient reduction of ethylene levels would allow storing these vegetables at 10 ° C (for pak choi, broccoli and mint) and 18 ° C (for green beans), considerably higher temperatures than currently recommended (0-5 ° C).

“The use of refrigeration is energy intensive and with the large volumes of fresh horticultural commodities that are marketed around the world, refrigeration contributes a significant proportion of total energy consumption. Actions that reduce energy usage are considered desirable from an environmental perspective to minimise the emissions of greenhouse gases, in addition to reducing the cost of energy consumption.”

 “An alternate technology to extend postharvest life is through reducing the concentration of ethylene in the atmosphere around produce. However, there have been few comprehensive studies that quantify the relationship between temperature and ethylene concentration. Wills et al (2014) reported the time to ripen banana fruit held at all combinations of temperature from 15 to 25°C and ethylene from 0.001 to 1.0 μL L−1, but no similar study has been reported for non-climacteric produce”.

 “The objective of this study is to examine the relationship between storage temperature and ethylene concentration on the postharvest life, as determined by consumer purchase expectations, of the non-climacteric vegetables, pak choi, mint, broccoli and green bean, and to examine the potential for low ethylene to reduce the need for refrigeration in storage and transport”.

 “Optimum storage conditions are at the lowest achievable ethylene concentration and lowest appropriate temperature considering chilling injury susceptibility. However, for produce marketed before the maximum period, acceptable quality can be maintained at above-optimal storage conditions. If the minimisation of energy is an important criterion, storage in reduced ethylene at a higher temperature is a viable option.  Of course, an ethylene intervention strategy comes at some cost and from an economic perspective should be less than the savings derived from lower energy usage”.

 “Regression equations generated from the storage data allowed for the calculation of the temperature and ethylene levels required for any nominated postharvest life. Using a 14-day postharvest life as an example, storage in ethylene at 0.001 μL/L would allow a storage temperature of about 10°C for pak choi, broccoli, and mint and about 18°C for green bean, temperatures well above the current recommendations of 0 to 5°C”.

In order to achieve the low ethylene levels (<0.001 μL / L) described in this article, which wil allow the maintenance of non-climacteric products at higher temperatures, it will be necessary to use ethylene removal technologies such as Bi-On, which is efficient and cost -effective.

 

 (1) Interaction of ethylene concentration and storage temperature on postharvest life of the green vegetables pak choi, broccoli, mint and green bean, Yongxin Li, RBH Wills and JG Golding; The Journal of Horticultural Science and Biotechnology (2017) 1-6