Prevention of Chilling Injury in Pomegranates Revisited: Pre- and Post-Harvest Factors, Mode of Actions, and Technologies Involved

Abstract

The storage life of pomegranate fruit (Punica granatum L.) is limited by decay, chilling injury, weight loss, and husk scald. In particular, chilling injury (CI) limits pomegranate long-term storage at chilling temperatures. CI manifests as skin browning that expands randomly with surface spots, albedo brown discoloration, and changes in aril colors from red to brown discoloration during handling or storage (6–8 weeks) at <5–7 °C. Since CI symptoms affect external and internal appearance, it significantly reduces pomegranate fruit marketability. Several postharvest treatments have been proposed to prevent CI, including atmospheric modifications (MA), heat treatments (HT), coatings, use of polyamines (PAs), salicylic acid (SA), jasmonates (JA), melatonin and glycine betaine (GB), among others. There is no complete understanding of the etiology and biochemistry of CI, however, a hypothetical model proposed herein indicates that oxidative stress plays a key role, which alters cell membrane functionality and integrity and alters protein/enzyme biosynthesis associated with chilling injury symptoms. This review discusses the hypothesized mechanism of CI based on recent research, its association to postharvest treatments, and their possible targets. It also indicates that the proposed mode of action model can be used to combine treatments in a hurdle synergistic or additive approach or as the basis for novel technological developments.

Classification of Healthy and Frozen Pomegranates Using Hyperspectral Imaging and Deep Learning

“…As a semi-tropical fruit, pomegranate is sensitive to post-harvest storage temperatures and, if exposed to cold temperatures above freezing for a long period of time, it will suffer chilling stress [2]. During the storage of pomegranates in the cold store, signs may appear that, if not detected and remedied in time, will cause significant damage.…”

The Simultaneous Use of 1-Methylcyclopropene and Methyl Jasmonate Vapor as an Innovative Strategy for Reducing Chilling Injury and Maintaining Pomegranate Fruit Quality at Suboptimal Temperatures

“…Other chemical substances such as methyl salicylate, γ-aminobutyric acid (GABA), or glycine betaine were able to reduce CI in pomegranate, orange, and kiwifruit during storage [ 10 , 11 , 12 ]. Other strategies as intermittent warming, controlled atmosphere, or the application of nitric oxide have demonstrated success in controlling CI [ 13 ]. Methyl jasmonate (MeJA) is an elicitor that stimulates plant growth and development and is involved in the plant defense system against several biotic and abiotic stresses [ 14 ].…”