Improving the protective features of fresh pistachios against chilling injury and enzymatic discoloration through the synergistic application of Ajwain seeds essential oils (Trachyspermum ammi) and carboxymethylcellulose
The thymol fraction present in Ajwain seed essential oil (Aj) exhibits antioxidant properties that can mitigate horticultural crop losses after harvest. This study was designed to analyze the influence of carboxymethyl cellulose (CMC 0.5 %) in combination with three concentrations of Aj (400, 800 and 1200 mg L−1) on fresh ‘Ahmad Aghaei’ pistachio fruits. After drying at ambient temperature and packaging, the fruits were stored at 2 ± 1 °C with 85 ± 2 % relative humidity. The combined treatments of CMC 0.5 % with Aj 400 and 800 scientifically controlled weight loss, chilling injury, decay, hull H2O2 levels, and enzyme activity compared to the control sample over an extended storage duration. The highest levels of chilling injury, decay and POD activity were observed in the samples treated with distilled water (control), while the lowest sensory scores were also recorded in the same treatment. Although CMC + Aj 1200 showed the highest chlorophyll content, it resulted in a negative effect on the aroma index. Combined treatments resulted in the highest lipid and hue index at the end of the storage period. In the control sample, the phenolic compounds decreased by 54 %, whereas the pistachios treated with CMC + Aj 800 experienced a 31 % decrease in phenolics. Overall, the application of CMC + Aj 800 successfully preserved the quantitative and qualitative attributes of Ahmad Aghaei pistachios for up to 50 days.
https://doi.org/10.1016/j.jspr.2025.102858
Comparative shelf-life study in dehydrated plums: use of potassium sorbate and its effect on microbial spoilage
Potassium sorbate is a preservative used to avoid microbial spoilage in dehydrated plums (prunes) during long travel distances and, therefore, improve the shelf life of prunes. In this study, prunes with and without sorbate were stored for 12 months at 4, 16, 20 and 37 °C. The physiological and biochemical indexes were measured and recorded monthly throughout the experimental period. The potassium sorbate was drastically desorbed from the fruit during the first months of the study. The results showed that 37 °C significantly affected the prunes quality, increasing the firmness and diminishing the moisture. While the other temperatures did not affect the quality of prunes. On the other hand, no significant differences were observed in the presence of mould and yeast for prunes with and without potassium sorbate independent of the storage temperature. Storage from 4 to 20 °C did not greatly affect the quality of the fruit stored for 12 months. However, storage at 37 °C significantly affected the quality of the prunes, mainly in terms of firmness.
https://doi.org/10.1016/j.lwt.2024.117004