Response of pomegranate arils (cv. Wonderful) to low oxygen stress under active modified atmosphere condition.

Abstract

Successful characterization of the relationship between respiration rate (RR) and low oxygen (O2 ) limit is critical for optimizing the modified atmosphere condition. It is well documented that a low O2 atmosphere reduces the RR of fresh produce, but could also lead to abiotic stress due to the accumulation of glycolysis end products. Therefore, this study investigated the response of pomegranate arils exposed to low O2 atmosphere (composed of 2 kPa O2 , 18 kPa carbon dioxide, and 80 kPa nitrogen) and identified the low O2 limit at 5 °C and 10 °C. The study aim was achieved by using real-time RR and respiration quotient (RQ) data, microbial growth, identifying changes in the fermentative volatile organic compounds profile, and the consumption of respiratory metabolites (organic acids and individual sugars). The gas concentrations changed significantly respective to the storage temperature and resulted in a significant change in the parameters studied. The response of pomegranate arils to low O2 stress involves making alterations to the metabolic composition, especially those involved in anaerobiosis, such as the accumulation of ethanol, and an immediate increase on RQ. Pomegranate arils (cv. Wonderful) can tolerate down to 1.9 kPa O2 and 2.3 kPa O2 concentrations at 5 °C and 10 °C respectively. © 2018 Society of Chemical Industry.