Glycine betaine, an emerging anti chllling injury preservative

Post-harvest preservation of fruit and vegetables in cold storage can be susceptible to chilling injury (CI). Glycine betaine (GB), an emerging anti-CI preservative, is drawing great attention due to effective cell membrane protection and free radical scavenging abilities, particularly in reducing browning and softening.

Drawing on hypotheses about membrane damage and reactive oxygen stress, we provide an overview of the biochemical mechanisms of CI and GB functioning mechanisms in postharvest fruit and vegetables.

Furthermore, we systematically review the mechanism and application of GB in cold storage preservation from diverse perspectives, including GB biosynthesis, oxidative metabolism, lipid membrane metabolism, sugar and energy metabolism, amino acid and protein metabolism, phytohormones, transcription and expression of related cold resistance genes, as well as the quality of GB-treated fruit and vegetables.

This article is anticipated to provide an essential basis for novel applications of GB in low-temperature preservation.

Graphical abstract

Introduction

Fresh fruit and vegetables are both highly nutritious and perishable. Low-temperature storage is an efficient preservation technique commonly used in handling fruit and vegetables throughout production, processing, and distribution to extend their storage life [1].

However, the irreversible physiological damage caused by chilling injury (CI) to fruit and vegetables results in several issues, including failure to ripen, rapid decay, reduction in shelf-life, commodity value and marketability as a consequence of improper cold storage temperature and time [2].

The mechanism and mitigation of CI remain a critical concern in agricultural products worldwide, especially for tropical and subtropical fruit and vegetables.

Causes of CI

CI signifies that a sudden drop in temperature or inappropriate low temperatures lasting for a long time causes physiological damage to the plant tissues, manifested as superficial pitting, denting, watery stains, flesh and peel browning, lignification, dehydration softening, as well as fruit immaturity [3].

Temperature, time duration at the chilling temperature, and temperature sensitivity of fruit and vegetables are critical factors influencing the extent of chilling damage.

The CI usually occurs between 0 °C and 13 °C with variations arising from diverse temperature sensitivity such as subtropical fruit and vegetables like zucchini and avocado which have a cold-sensitive temperature of 5–8 °C, while banana and guava which are of tropical origin may be below 13 °C [4], [5].

Natural anti CI substances

The naturally occurring small-molecule signal substances during the plant growth process have attracted attention from scientists with the aim of preventing the occurrence of CI and its consequences thereof during cold storage. 

These include glycine betaine (GB), methyl jasmonate, melatonin, γ-aminobutyric acid (GABA) [6], [7], [8], [9]. These natural anti-CI ingredients not only act as pivotal regulators of redox homeostasis and physiological molecular responses in a stressful environment, but also enhance the quality, stability and safety of fruit and vegetables in the post-harvest application, and extending preservation time [10].

GB, several EU approved uses

GB (N, N, N-trimethyl­glycine, C5H11NO2) is a low molecular amphitropic osmoprotectant, also known as betaine commonly existing in cells and organelles as an intermediate metabolite in biological metabolism [11]. 

The European Commission issued Regulation (EU) 2019/1294, which approved betaine as a novel food in the market on the 1st August 2019. In earlier times, GB was applied to promote plant growth and survival to counteract stress-induced metabolic dysfunction [12].

Nowadays, GB has been used in various fields of research such as crop cultivation, fruit and vegetable preservation, livestock breeding, and disease treatment [13], [14], [15], [16].

GB as an alkaloid modulates cellular osmolarity to keep up the stability of internal cell solute concentration under osmotic stress in response to the damage of cell membranes from excessive accumulation of inorganic ions, defending plant tissues from environmental stress, such as cold, drought and salt stress [17].

GB application diminishes CI symptoms

Recent studies confirm that GB accumulation helps to ameliorate CI in harvested fruit [18]. The accumulation of GB is concomitant with the enhanced temperature tolerance controlled by transcription factors [19]. 

GB treatment effectively diminishes CI symptoms while at the same time promoting the retention of nutrients such as sugars, vitamins and antioxidants, thus exhibiting the significant potential for the postharvest cold-resistant in the low-temperature storage of various fruit and vegetables as shown in Table 1 (see the original paper in the Sources).

This review focused on the biochemical mechanisms of CI as well as GB functioning mechanisms and the application of GB in cold storage preservation of fruit and vegetables (Fig. 1).

It systematically summarised the GB-mediated CI from diverse perspectives including GB biosynthesis, GB-regulated oxidative metabolism, lipid membrane metabolism, sugar and energy metabolism, amino acid and protein metabolism, plant hormones, cold signaling pathways and gene expression, as well as the quality of GB-treated fruit and vegetables as reflected in Fig. 2.

Furthermore, the purpose of this article is to present a theoretical basis for wider applications of GB in low-temperature fruit and vegetable preservation.

Sources

The underpinning mechanisms and applications of glycine betaine on chilling injury in fruit and vegetables
Dengyi Ye, Xiyu Wang, Jiali Guo, Jing Ren, 
Bing Li, Quanliang Li, Yanjun Chen, Xiaomeng Wang, Moeketsi Ntakatsane, Ping Chen 
Microchemical Journal
Volume 212, May 2025, 113290
https://doi.org/10.1016/j.microc.2025.113290

Main picture
Andrés F. López Camelo, Manual Para la Preparación y Venta de Frutas y Hortalizas - Del campo al mercado 
https://www.fao.org/4/y4893s/y4893s06.htm