Natural postharvest treatments to potato tubers stored at different temperatures delayed sprouting and preserved tuber quality

The current study aimed to explore low-cost, non-toxic, and efficient natural potato tuber suppressants. The sprout suppression properties of rosemary essential oil and coriander seed extract were assessed, and the quality of potato tubers was evaluated during storage at 20 and 30°C. The sprouting rate and weight loss as well as contents of soluble sugar, starch , malondialdehyde (MDA) and hydrogen peroxide (H2O2) were determined. Additionally, the ferric-reducing antioxidant power (FRAP) and DPPH radical scavenging activity of the tubers was evaluated. The activities of catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), ascorbate peroxidase (APX), ascorbate oxidase (ASO), and their corresponding substrates of ascorbic acid (AsA), total phenolics (TPC), and total flavonoids (TFC) were also measured to determine if they depleted over the storage period. Both rosemary essential oil and coriander seed extract hindered sprouting up to 8 weeks post-treatment for tubers stored at 20°C. This was demonstrated by lower values of sprouting and weight loss at the end of the storage period. Specifically, when rosemary essential oil was used, and the tubers were stored at 20°C, there was an increase in starch content, a decrease in sugar content, an enhancement in the levels of DPPH, FRAP, AsA, TPC, and TFC, while the levels of CAT, POD, PPO, APX, ASO, MDA, and H2O2 were decreased. The results highlight the effectiveness of the potency of rosemary essential oil treatment in delaying sprouting and preserving the fresh appearance, starch content, and antioxidants of stored potato tubers, which are crucial indicators of their quality.