The use of low-pressure cold plasma optimization for microbial decontamination and physicochemical preservation of strawberries

Abstract

Strawberries are highly perishable products due to the presence of elevated water levels, thereby necessitating postharvest treatments to enhance physicochemical quality (PQ) and shelf-life. Although several studies have focused on the development of cold plasma processes as postharvest treatments, the effect of the processing parameters remains unexplored. Therefore, this study aimed to assess the use of low-pressure cold plasma (LP-CP) for microbial decontamination and physicochemical preservation of strawberries using Taguchi orthogonal array design (OAD). The results showed that optimizing LP-CP treatment power, exposure time, and reactor pressure delayed the deterioration rates of strawberries by approximately 10–60 %. Total plate count (TPC) showed that LP-CP treatment with 90 W for 90 s at 0.076 Torr was the optimum condition for microbial decontamination. Color change (CC) was optimally inhibited with 90 W for 60 s in 0.076 Torr. Meanwhile, the optimum condition for maintaining electrolyte leakage (EL) was 30 W for 30 s at 0.076 Torr. Optimal ascorbic acid (AA) content and antioxidant capacity (DPPH) were obtained at 30 W for 30 s in <0.756 Torr. LP-CP processing parameters of power (up to 59–96 %) had the most significant contribution (p < 0.05), followed by time (up to 29 %) and pressure (up to 10 %). Based on the results, reducing microbial contamination preserved the surface color of strawberries. Lowering LP-CP power input, exposure time, and reactor pressure was suggested to enhance the membrane integrity and antioxidant properties of the samples. The results of this study could promote green industrialization of strawberries by reducing waste and improving process efficiency to achieve sustainable development.

Keywords

• Low-pressure cold plasma
• Orthogonal array
• Quality
• Strawberries
• Taguchi