Comparison of Decontamination Efficacy between the Rapid Hygrothermal Pasteurization and Sodium Hypochlorite Treatments

Abstract

We developed a novel rapid hygrothermal pasteurization (RHP) method using saturated water vapor with a dew point of 100℃. The aim of this paper is to compare the effect of RHP treatment versus conventional sodium hypochlorite (NaClO) treatments on inactivation of natural mesophilic bacteria and quality attributes on fruits and vegetables. The RHP treatment was performed within a second by free-falling samples (cabbage, cucumber, carrot, bell pepper, pineapple and melon) through cylindrical processing chamber filled with steam. NaClO treatment was performed by washing samples with NaClO solution (100 mg/mL of free chlorine (pH 7), for 1 min). The RHP treatment showed a significantly higher inactivation effect than NaClO treatment on all tested samples. The RHP treatment had a slightly larger influence on color and vitamin C content than NaClO treatment in cabbage. Furthermore, the effects of treatment time and operated temperature were also determined using microbial model system. Elongation of treatment time did not significantly increase the microbial inactivation effect. Lowering of operated temperature by mixing air into steam tended to decrease the inactivation effect. From these results, RHP treatment could be used as an alternative method for decontaminating microorganisms on fruits and vegetables, except on leafy vegetable. In addition, it is suggested that microbial inactivation by RHP treatment was achieved through the initial condensation stage of water vapor on sample surface. By contrast, interfusion of air disturbed the effective condensation of water vapor

Optimization of Process Variables for Retention of Functional Properties of Bitter Melon (Momordica Charantia L.) and its Shelf-Life Extension

“…26 Weston, Ito 27 and D'Aquino, Suming 28 have also reported antagonist effects of NaClO on vitamin C. The vitamin C content was slightly reduced after washing the fresh-cut lettuce with NaClO solution as compared to the unwashed samples. 29 The decrease in vitamin C content was similar to findings by Tirawat, Kunimoto 30 showing the significant decrease in vitamin C content in cabbage. after oxidation mediated by hypochlorous acid in presence of sodium hypochlorite (HOCl/-OCl).…”

Chemical interventions for extending shelf life of minimally processed bitter gourd (Momordica charantia L.)

“…The loss of ascorbic acid content might be partly due to large surface area of the sliced bitter gourd. Vitamin C loss was also reported recently in stored fresh-cut cantaloupe (Beaulieu and Lea, 2007;Gil et al, 2006) [7,13] in cabbage (Tirawat et al, 2013) [37] and in lettuce (Sheetal Devi et al, 2019) [30] . Dipping of bitter gourd slices in 2% ascorbic acid as pretreatment might have fortified the ascorbic acid content.…”