Optimized Preparation of Methyl Salicylate Hydrogel and Its Inhibition Effect on Potato Tuber Sprouting

Abstract

Potato tuber sprout results in nutrient loss and solanine production. Essential oils have been mentioned to reduce sprouting; however, they can easily evaporate and decompose, thus restricting their application. In this paper, the inhibition effect of methyl salicylate (MeSA) as the main component of wintergreen essential oil on tuber sprouting was evaluated, and MeSA hydrogel was prepared by using the ionic gel method to improve the sprout inhibition efficiency. Based on SEM, FTIR, XRD, and DSC images, MeSA was encapsulated successfully in calcium alginate hydrogel, and the thermal stability of hydrogel was improved. MeSA direct fumigation released sharply on the first day, while MeSA in hydrogel released slowly and steadily; the release of MeSA content was 0.0085 mg mL−1 on the 7th day. The optimized formulations of MeSA hydrogel were as follows: 1.9% of sodium alginate, 2.2% of CaCl2, 1.9:1 of core–wall ratio, and 0.15% of Tween-80. The inhibition effect of MeSA hydrogel was better than that of pure MeSA at 18 days, the sprouting rates of the MeSA and MeSA hydrogel were 42.50% and 13.33%, and the corresponding sprouting indexes were 8.57% and 2.86%, respectively. MeSA was found to inhibit potato tuber sprouting for the first time in this paper; MeSA hydrogel can enhance the inhibitory effect of MeSA on potato sprouting.

Keywords

• potato tuber
• sprout inhibition
• methyl salicylate
• hydrogel