On the Biochemical and Physiological Responses of ‘Crimson Seedless’ Grapes Coated with an Edible Composite of Pectin, Polyphenylene Alcohol, and Salicylic Acid

The ‘Crimson seedless’ grape encountered several difficulties during shelf life, including weight loss, rachis browning, and berry shattering. The effect of exogenous pectin (PE) and polyphenol alcohol (PVA) with supporting salicylic acid (SA) at different concentrations (0, 1, and 2 mM) was applied. The coating was applied to bunches for 5 min and stored at room temperature (26 ± 1 °C and RH 65 ± 3%) for 4 days. In this study, postharvest application of PE + PVA-SA can significantly reduce the cell wall degradation enzyme activities of ‘Crimson seedless’ grape during shelf life. ‘Crimson seedless’ bunches, treated with PE + PVA-SA 2 mmol L−1, had a lowered rachis browning index (RB index), weight loss (WL%), and berry shattering percentage (BS%) and preserved berry color hue angle (ho) compared to untreated bunches during shelf-life duration. Moreover, the PE + PVA-SA 2 mM improved berry firmness (BF) and removal force (BRF). It also improved the soluble solid content (SSC%), titratable acidity (TA%), and SSC: TA-ratio, for assessing berry maturity. The cellular metabolism enzyme activities (CMEAs) of the cell wall such as polygalacturonase (PG), cellulase (CEL), xylanase (XYL), and pectinase (PT) were minimized by applying PE + PVA-SA 2 mM coatings throughout storage duration. The accumulation of malondialdehyde (MDA) and cell wall damage, as well as the electrolyte leakage percentage (EL%), was reduced. PE + PVA-SA 2 mM maintained DPPH radical quenching activities and minimized O2− and H2O2 production rates. Collectively, these findings suggest that PE + PVA with the presence of SA as a coating treatment preserved ‘Crimson seedless’ bunches during shelf life. PE + PVA-SA 2 mM might be at least partially ascribed to the enhancement of bunches’ quality traits as well as inhibiting cell wall damage during the shelf-life period

Postharvest Treatment of ‘Florida Prince’ Peaches with a Calcium Nanoparticle–Ascorbic Acid Mixture during Cold Storage and Its Effect on Antioxidant Enzyme Activities

Chilling injury (CI) is a physiological disorder resulting from low storage temperatures that affects the fruit quality and marketing of the ‘Florida Prince’ peach. In this study, the exogenous application of a mixture of calcium nanoparticles (CaNPs) and ascorbic acid was found to significantly alleviate the symptoms of CI in peaches during cold storage. Fruits were treated with CaNPs plus different concentrations of ascorbic acid (AA; 0, 3, 6, and 9 mM). Peaches were immersed in CaNP–AA for 15 min before being stored at 4 ± 1 °C and 95 ± 1% RH for 30 days. We observed that the 9 mM CaNP–AA treatment lowered the values for the CI index, ion leakage, and malondialdehyde (MDA) content and increased antioxidant enzyme activities (AEAs), such as for ascorbate oxidase (APX), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR). Furthermore, the treatment reduced the accumulation of both H2O2 and O2•− and increased the level of DPPH reduction throughout the duration of cold storage. Our results suggest that 9 mM CaNP–AA treatment suppresses the incidence of CI in peach fruit throughout cold storage, possibly because 9 mM CaNP–AA is at least partly involved in enhancing the antioxidant system via its effect on antioxidant substances. The results indicate that applying the 9 mM CaNP–AA treatment afforded peaches with enhanced tolerance against cold storage stress

The Quality of Superior Seedless Bunches during Shelf Life as Determined by Growth on Different Rootstocks

Vineyard rootstocks are an important tool in the local and international market for growing the Superior Seedless grape cultivar, which is highly favored by customers. As a result, it is vital to pay close attention to the quality of clusters during handling. The current study aimed to determine whether Superior Seedless vines can be grown on specific rootstocks, resulting in higher quality during shelf life. Vines of the Superior Seedless vine cultivar that were used were 13 years old and had been grown on sandy soil. These vines were grafted onto four different rootstocks (genotypes), namely Freedom, 1103 Paulsen, SO4, and Own Root. The soluble solids content (SSC%) was selected as 16%. Bunches were subsequently stored in the lab at 27 ± 1 °C with 57 ± 3% air relative humidity for three days. Rootstock 1103 Paulsen’s quality was found to be superior to that of the other rootstocks, according to the results of the study. Rootstock 1103 Paulsen maintained its ascorbic acid (AA) content, which is reflected in its antioxidant capacity, according to the results. In addition, lipid peroxidation accumulation and ion leakage percentages indicated that oxidative reactions were at their lowest levels. The results show that 1103 Paulsen decreases cellular metabolism enzyme activities at the shelf life level and improves the bunch quality of Superior Seedless (scion) grapes within 4 days of application. As a whole, the results show that the 1103 Paulsen rootstock produces Superior Seedless bunches of a high quality that is preserved throughout the shelf life period

Influence of the Position of Mango Fruit on the Tree (Mangifera indica L. CV. ‘Zibda’) on Chilling Sensitivity and Antioxidant Enzyme Activity

Mango fruits sourced from tropical yields have had a high commercial comeback from being viewed as susceptible to chilling injury under long storage durations. When the fruits are exposed to cold storage, this results in physiological changes due to the side effects of the storage on the fruits, expanding the rates of loss during the period between harvest and marketing. It is difficult to harvest mangoes as the fruits show varying maturities and are located in different positions on the trees. The purpose of this study was to test the idea that fruits’ location on the tree influences how the fruit behaves during cold storage. During two seasons (2019–2020), the impact of on-tree fruit location, i.e., sunny side (SUN; fruit exposed to the sun for most of the day), shade (SHA; fruit grown on the shady side of trees), and inside the canopy (INS; fruit grown inside the tree canopy), on the chilling sensitivity and the activities of antioxidant enzymes of ‘Zibda’ mangos stored at a low temperature (4 ± 1 °C) for 35 days was determined. In contrast to SHA and SUN mangos, INS fruits were shown to be progressively tolerant to low storage temperatures. These fruits also showed the highest activities of ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD). In addition, the contents of O2− and H2O2 decreased in INS fruit during storage. Consequently, the cell membrane compartments were maintained, showing low accumulation of both malondialdehyde (MDA) and the protein carbonyl group (PCG) during storage. These results indicate that the fruit positions can also be considered at the time of harvesting for the classification of fruits before cold storage. This classification can also be added to the mango trading protocol to minimize the loss of economic returns by chilling injury

Influence of the Position of Mango Fruit on the Tree (<i>Mangifera indica</i> L. CV. ‘Zibda’) on Chilling Sensitivity and Antioxidant Enzyme Activity

Mango fruits sourced from tropical yields have had a high commercial comeback from being viewed as susceptible to chilling injury under long storage durations. When the fruits are exposed to cold storage, this results in physiological changes due to the side effects of the storage on the fruits, expanding the rates of loss during the period between harvest and marketing. It is difficult to harvest mangoes as the fruits show varying maturities and are located in different positions on the trees. The purpose of this study was to test the idea that fruits’ location on the tree influences how the fruit behaves during cold storage. During two seasons (2019–2020), the impact of on-tree fruit location, i.e., sunny side (SUN; fruit exposed to the sun for most of the day), shade (SHA; fruit grown on the shady side of trees), and inside the canopy (INS; fruit grown inside the tree canopy), on the chilling sensitivity and the activities of antioxidant enzymes of ‘Zibda’ mangos stored at a low temperature (4 ± 1 °C) for 35 days was determined. In contrast to SHA and SUN mangos, INS fruits were shown to be progressively tolerant to low storage temperatures. These fruits also showed the highest activities of ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD). In addition, the contents of O2− and H2O2 decreased in INS fruit during storage. Consequently, the cell membrane compartments were maintained, showing low accumulation of both malondialdehyde (MDA) and the protein carbonyl group (PCG) during storage. These results indicate that the fruit positions can also be considered at the time of harvesting for the classification of fruits before cold storage. This classification can also be added to the mango trading protocol to minimize the loss of economic returns by chilling injury

Growth, Yield, and Bunch Quality of “Superior Seedless” Vines Grown on Different Rootstocks Change in Response to Salt Stress

The growth and quality of vines are negatively affected by soil salinity if enough salts accumulate in the root zone. As part of the current study, we estimated the remediating effects of rootstocks under salinity. For this reason, “superior seedless” vines were grafted onto three different rootstocks, such as SO4, 1103 Paulson, and own-root (“superior seedless” with their own-root). The experiment was conducted in the 2019 and 2020 seasons. This study examines the effects of different rootstocks on vine growth, yield, and quality using “superior seedless” vines grown in sandy soil with salinity. Four stages of berry development were examined (flowering, fruit set, veraison, and harvest time). At harvest, yield characteristics (clusters per vine and cluster weight) were also assessed. Each parameter of the growth season was influenced separately. The K+ and Na+ ratios were also significantly increased, as were the salinity symptoms index and bunch yield per vine and quality. Rootstock 1103 Paulson improved photosynthetic pigments, K+ accumulation, Na+ uptake, and cell membrane damage in “superior seedless” vines compared to other rootstocks, according to the study results. As determined in the arid regions of northwestern Egypt, the 1103 Paulson can mitigate salinity issues when planting “superior seedless” vines on sandy soil

The Combined Effect of Hot Water Treatment and Chitosan Coating on Mango (Mangifera indica L. cv. Kent) Fruits to Control Postharvest Deterioration and Increase Fruit Quality

The synergistic effect of dipping in 55 &deg;C for 5 min of hot water (HW) and 1% chitosan coating during the storage of mango at 13 &plusmn; 0.5 &deg;C and 85%&ndash;90% relative humidity for 28 days was investigated. The combined treatment significantly suppressed the fruit decay percentage compared with both the single treatment and the control. In addition, the specific activities of key plant defense-related enzymes, including peroxidase (POD) and catalase (CAT), markedly increased. The increase occurred in the pulp of the fruits treated with the combined treatment compared to those treated with HW or chitosan alone. While the control fruits showed the lowest values, the combination of pre-storage HW treatment and chitosan coating maintained higher values of flesh hue angle (h&deg;), vitamin C content, membrane stability index (MSI) percentage, as well as lower weight loss compared with the untreated mango fruits. The combined treatment and chitosan treatment alone delayed fruit ripening by keeping fruit firmness, lessening the continuous increase of total soluble solids (TSS), and slowing the decrease in titratable acidity (TA). The results showed that the combined application of HW treatment and chitosan coating can be used as an effective strategy to suppress postharvest decay and improve the quality of mango fruits