Temporal Changes and Correlations between Quality Loss Parameters, Antioxidant Properties and Enzyme Activities in Apricot Fruit Treated with Methyl Jasmonate and Salicylic Acid during Cold Storage and Shelf-Life

József Nyéki,Amin Ammar,Szilárd Szabó,Ahmed Ezzat,Bianka Molnár,Zoltán Szabó,Attila Hegedűs,Imre J. Holb

doi:10.3390/app10228071

Abstract

The apricot storability is one of the largest challenges, which the apricot industry has to face all over the world; therefore, finding options for prolonging fruit quality during cold storage (CS) and shelf-life (SL) will help to decrease postharvest losses of apricot. The aim of this apricot fruit work was to study the temporal changes and correlations of 10 quality parameters (quality losses, antioxidant properties and enzyme activities) in the postharvest treatments of methyl jasmonate (MeJA) and salicylic acid (SA) under 1 °C CS (7, 14 and 21 days) and 25 °C SL (4 and 8 days after the 21-day CS) treatments. MeJA and SA significantly decreased the quality loss of chilling injury (CI) and fruit decay (FD) at all dates for both storage conditions. MeJA- and SA-treated fruits increased total antioxidant capacity (TAC), total soluble phenolic compounds (TSPC) and carotenoids contents (TCC) at all dates of both storage treatments. In contrast, the ascorbic acid content (AAC) increased only until days 14 and 4 in the CS and SL treatments, respectively. Among enzyme activity parameters, the activities of phenylalanine ammonia-lyase (PAL), peroxidase and superoxide dismutase (SOD) were significantly increased in the MeJA and SA treatments in all dates of both storage treatments. Catalase (CAT) activity increased in the SA and control treatments, while it decreased in the MeJA treatment in both storage conditions. In both the MeJA and the SA treatments, six pair-variables (FD vs. CI, PAL vs. CAT, PAL vs. SOD, TAC vs. SOD, TAC vs. FD, and AAC vs. CI) were significant in Pearson correlation and regression analyses among the 45 parameters pairs. Principal component analyses explained 89.3% of the total variance and PC1 accounted for 55.6% of the variance and correlated with the CI, FD, TAC, TSPC, TCC, PAL and SOD, indicating strong connections among most parameters. In conclusion, MeJA and SA are practically useful and inexpensive techniques to maintain quality attributes of CI, FD, TAC, TSPC, TCC, PAL, POD and SOD in apricot fruit during both CS and SL conditions.

Highlights

Minerals, vitamins, and antioxidant materials in fruit crops are essential sources for human health care [1,2]
Fruit treated with methyl jasmonate (MeJA) showed significantly lower chilling injury (CI) index in the cold storage (CS) treatments at day 21 and in the SL treatments at day 8 compared to corresponding salicylic acid (SA) treatments
PC1 accounted for 55.6% of the variance and correlated with the CI, fruit decay (FD), total antioxidant capacity (TAC), total soluble phenolic compounds (TSPC), Total carotenoids content (TCC) (Carotenoids), phenylalanine ammonia-lyase (PAL), and superoxide dismutase (SOD)

Summary

Introduction

Vitamins, and antioxidant materials in fruit crops are essential sources for human health care [1,2]. The amount and longevity of these sources in stone fruits are highly dependent on the pre- and postharvest quality of the fruit e.g., [3,4,5]. The post-harvest life of apricot (Prunus armeniaca) is short due to its climacteric nature [5]. 15–30 days after harvest if the fruit is stored at low temperature under cold storage (CS), e.g., [6,7,8,9], and this quality can be kept for up to a further 5 days at 25 ◦ C under shelf-life (SL) conditions [10]. Longer storage at low temperatures can cause symptoms of chilling injury and/or fruit decay incidence in the apricot fruit e.g., [5,7,11].

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