Sulphur Dioxide Pads Can Reduce Gray Mold While Maintaining the Quality of Clamshell-Packaged ‘BRS Nubia’ Seeded Table Grapes Grown under Protected Cultivation

Abstract

The purpose of this research is to test the efficacy of different types of SO2-generating pads on the incidence of gray mold, and on the physicochemical properties of quality of ‘BRS Nubia’ seeded table grapes grown under protected cultivation. Four types of SO2-generating pads, 5 or 8 g of sodium metabisulfite dual release pads, and 4 or 7 g of sodium metabisulfite slow release pads, were used. Grapes bunches were harvested from a vineyard covered with plastic mash and stored in a cold room at 1 ± 1 °C for 45 days followed by 6 days of shelf life at 22 ± 1 °C at a high relative humidity (>95%). The results showed that SO2-generating pads with a dual release of 5 or 8 g completely inhibited the development of gray mold at all evaluation times. Also, a high reduction of the disease incidence was achieved by using a slow release of 4 g. The study confirmed that SO2-generating pads did not alter the physicochemical properties of ‘BRS Nubia’ seeded table grapes including mass loss, berry firmness, color index, total anthocyanin concentration, total soluble solids (TSS), titratable acidity (TA), and the TSS/TA ratio. Slow release pads at 4 and 7 g reduced the percentage of shattered berries by 56 and 48% as compared to control only after 6 days of shelf life. Also, all types of SO2-generating pads reduced the stem browning score at the end of cold storage. The 5 or 8 g dual release pads and 4 g slow release pads can be considered for effective controlling of gray mold for ‘BRS Nubia’ table grapes grown under protected cultivation while maintaining grape quality.

Impact of sulphur dioxide generating pads and liners on enhancing market acceptability and post-harvest life of grapes

“…The gas released from sulphur pads may have checked the primary disease progress and killed pathogen more efficiently when combined with the liners. These results are in agreement with the previous studies against graymold of stored 'BRS Vitoria' table grapes (Domingues et al, 2018) and clamshell packaged 'BRS Nubia' Seeded Table Grapes (Youssef et al, 2020). Since the release of SO from 2 sodium metabisulfite in pads is function of humidity inside the packaging, the role of liners in the performance of slow release SO -generating pads can be explained by diverse permeability 2 provided by LDPE and newspaper liners, thereby controlling the concentration of gas inside the packaging.…”

Trends in Smart Packaging Technologies for Sustainable Monitoring of Food Quality and Safety

“…For pineapple packaging, sulfur dioxide emitters have now been utilized to inhibit mold growth by releasing antifungal substances into the package headspace [64]. Youssef et al [65] analyzed the impact of several forms of SO2-generating pads on the development of gray molds and physicochemical attributes of the 'BRS Nubia' seeded grape variety and revealed the best type of SO2generating pads for minimizing gray mold in table grapes while retaining fruit quality. The application of SO2 to blueberries, which are highly susceptible to postharvest decay, has been proven to successfully minimize deterioration over prolonged storage [66].…”

SO2-generating pads reduce gray mold in clamshell-packaged ‘Rubi’ table grapes grown under a two-cropping per year system

“…For this reason, the integration of management in the field with phytosanitary treatments and the use of appropriate packaging during cold storage are the commercial strategies that most contribute to reducing losses and controlling postharvest diseases (Palou et al, 2002;Droby & Lichter, 2004;Liguori, Sortino, Pasquale, & Inglese, 2015;Salem, Youssef, & Sanzani, 2016). Among attempts to reduce the incidence of B. cinerea postharvest in different grape cultivars, the use of SO 2 -generating pads during cold storage demonstrated good performance (Ahmed et al, 2018;Domingues et al, 2018;Chaves et al, 2019;Youssef, Chaves, Mühlbeier, & Roberto, 2020), mainly due to its efficiency, ease of use, affordable cost and low health risk when compared to fungicides (Melgarejo-Flores et al, 2013). This gas, in addition to inhibiting the development of microorganisms, has antioxidant action, influencing the physiological processes of the bunch itself, for example, maintaining the rachis or stem green and fresh (Muñoz, Benato, Sigrist, Oliveira, & Corrêa, 2000;Zoffoli & Latorre, 2011).…”