Bell peppers (Capsicum annuum L.) are prone to chilling injury (CI) when stored at temperatures below 7 °C. Melatonin, a natural plant regulator, plays a critical role in defending against different pre- and post-harvest abiotic stresses, including those associated with cold storage. This study aimed to assess the effects of applying exogenous melatonin alone and in combination with a commercial wax on the CI tolerance, postharvest life, and potential biomarker search of red bell peppers. In the initial experiment, the effective melatonin concentration to reduce CI effects was determined. Peppers were sprayed with either distilled water (control) or a melatonin aqueous solution (M100 = 100 μM or M500 = 500 μM) and then stored for 33 d at 4 °C, followed by 2 d at 20 °C. The M500 treatment proved to be more effective in reducing fruit CI incidence (superficial scalds) and metabolic rate, while weight loss, softening, and color were comparable to the control. A second experiment assessed the potential synergistic effects of a combined melatonin and commercial wax treatment on pepper CI and quality. Fruits were sprayed with distilled water (control), melatonin (M500), commercial wax (Wax), or the combined treatment (Wax + M500) and stored for 28 d at 4 °C, followed by 2 d at 20 °C. The Wax + M500 was the most effective in significantly reducing the incidence of fruit CI symptoms and calyx fungal infection. Furthermore, this combined treatment enhanced fruit weight loss prevention compared with individual melatonin or wax treatment. Also, Wax + M500-treated peppers exhibited notable proline accumulation, indicative of a metabolic response counteracting the cold effects, resulting in better fruit stress acclimation. This treatment also preserved the peppers’ color and antioxidant capacity. In summary, these findings highlight the suitability of applying a combined Wax + M500 treatment as a highly effective strategy to enhance the CI tolerance of peppers and extend their postharvest life.

In recent years there has been a marked increase in the demand for fresh-cut fruit. Although these products have high user convenience, they are extremely perishable. Consequently, they must be marketed within a very short period. A number of studies have shown that brief UV-C irradiation prior to storage may reduce postharvest deterioration in whole fruit. Herein, we evaluated the influence of different UV-C dose and intensity combinations on the quality and shelf-life of fresh-cut strawberries. Fresh berries were cut in wedges and subjected to brief UV-C treatments having different combinations of radiation intensity (0, 9, or 36 W m-2) and dose (0, 2, or 4 kJ m-2). Treatments with a dosage of 4 kJ m-2 at an intensity of 36 W m-2 decreased decay, juice leakage, dehydration softening, and yeasts and mold counts. UV-C treated berries also scored better in freshness color and overall acceptability in consumer tests. The treatments did not affect the acidity, soluble solids, or phenolic compounds. Results suggest that short UV-C treatment could be useful to supplement cold storage, extending the shelf-life of fresh-cut strawberries.

Eggplant is highly susceptible to chilling injury (CI) when stored at temperatures below 10 °C. This study evaluated the efficacy of glycine betaine (GB) as a pre-storage treatment to enhance chilling tolerance in eggplant, focusing on tissue-specific responses in the peel and flesh. GB concentrations of 0, 5, and 10 mM were tested, with 10 mM identified as the most effective in mitigating CI symptoms and weight loss. Subsequently, eggplants treated with 10 mM GB were stored for 21 days at 4 °C, followed by 2 days at 20 °C, to assess their physiological and biochemical properties. At the end of the storage period, GB treatment significantly reduced all CI-related indicators, including the CI index, weight loss, respiration rate, softening, flesh browning, electrolyte leakage, and malondialdehyde content, thereby extending shelf life by five days compared with untreated fruit. Principal component analysis revealed that severe CI in control fruit was associated with elevated levels of proline, endogenous GB, and unsaturated fatty acids (UFAs) in the peel, indicating that this outer tissue is the primary site of cold-stress responses in eggplant. Conversely, GB-treated fruit exhibited enhanced chilling tolerance characterized by reduced softening, greater antioxidant retention in both tissues, and maintenance of UFA levels in the flesh, while peel proline, GB, and fatty acid contents remained stable. Overall, our findings provide the first evidence that GB confers cold protection by modulating tissue-specific metabolic responses in eggplant peel and flesh, offering a simple and cost-effective strategy to extend shelf life.

The growing interest in healthy foods has increased the global demand for pecan nuts (Carya illinoinensis). Shelled nuts have gained market share due to their convenience compared to in-shell kernels. However, even after short-term storage, shelled kernels are prone to surface ambering and rancidity. Herein we evaluated the quality of pecan nuts (cvs. ‘Pawnee’ and ‘Stuart’) shelled upon arrival at the packinghouse and kept for 150 days (20 °C, 65% RH) in air (Shelled-Air) or vacuum (Shelled-Vac) and compared them to nuts stored in-shell in air and shelled immediately prior to commercial shipping (In shell-Air). Changes in color, free fatty acids, soluble phenolics, total volatile organic compounds (VOCs), volatile aldehydes, and sensory quality were determined. Shelled-Air kernels browned rapidly, whereas the In shell-Air treated nuts evidenced the least color change along storage. The In shell-Air storage strategy also yielded the highest proportion of premium nuts after 100 and 150 days of storage. At the last sampling date In shell-Air also showed 3 to 4 times lower production the production of aldehydes and VOCs than the nuts shelled stored in air or vacuum, and received the highest consumer color, and taste sensory scores. In contrast, neither shelling time nor storage atmosphere significantly affected the contents of ethanol soluble phenolic compounds or free fatty acids. Shelled nuts stored under vacuum showed improved quality over air-stored kernels only when the storage period was longer than 50 days. Overall, keeping pecans in-shell and cracking them immediately prior to shipping is the best strategy during packinghouse storage. Vacuum packaging of shelled kernels is recommended only if storage time exceeds 50 days.