Preserving phytochemical properties and antioxidant and enzymes activities in raspberry fruits with Satureja sahendica essential oil nanoemulsion: A strategy for enhancing raspberry fruits shelf life

The importance of post-harvest systems in addressing global food security, reducing poverty, and promoting sustainable agriculture is becoming widely acknowledged. Nevertheless, the limitations of existing post-harvest chemical treatments and the imposition of strict regulations highlight the need for innovative alternatives. Nano-formulated natural substances present a promising and cost-effective strategy for improving post-harvest management, meeting the growing consumer demand for safer and healthier food products. The present study has demonstrated that treating raspberries with a nanoemulsion derived from Satureja sahendica essential oil significantly extends post-harvest shelf-life of the fruits. This efficacy is attributed to the amplified surface area interaction facilitated by the S. sahendica essential oil nanoemulsion treatment on the fruit, showing a notable level of statistical significance (P ≤ 0.01). Our results suggest that the application of these treatments, particularly at a concentration of 300 μL L−1, effectively maintained higher levels of phenolic compounds in the treated fruits, including total phenol, flavonoid, anthocyanin, ascorbic acid, and rutin in comparison with the untreated fruits. Antioxidant activity assessments using the FRAP method revealed that fruits treated with a 200 μL L−1 concentration of nano essential oil exhibited the highest antioxidant activity on days six and nine post-storage, with values of 14.80 and 14.42 nm Fe++ ml−1 juice, respectively. Furthermore, our investigation confirmed that the enzyme activities of PAL, TAL, and CAT were markedly enhanced in samples treated with the 300 μL L−1 concentration, surpassing the performance of other tested concentrations. Generally, a concentration of 300 μL L−1 of nanoemulsion was more effective in providing a longer storage life with acceptable external and internal qualities in raspberry fruit.