Effect of plasma-activated water on microbial quality and physicochemical characteristics of mung bean sprouts

• Published in: Innovative food science & emerging technologies Vol. 52; pp. 49 - 56
• Main Authors: Xiang, Qisen, Liu, Xiufang, Liu, Shengnan, Ma, Yunfang, Xu, Chunqing, Bai, Yanhong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-03-2019
• Subjects: Mung bean sprouts; Physicochemical characteristics; Plasma-activated water; Sensory quality; Mung bean sprouts; Plasma-activated water; Physicochemical characteristics; Sensory quality
• ISSN: 1466-8564; 1878-5522
• DOI: 10.1016/j.ifset.2018.11.012

The efficacy of nonthermal plasma-activated water (PAW) in the decontamination of mung bean sprouts was evaluated in this work. After being treated with PAW for 30 min, the populations of total aerobic bacteria and total yeasts and moulds on mung bean sprouts were decreased by 2.32- and 2.84- log10 CFU/g, respectively. The PAW treatment had no significant effect on the antioxidant potential of mung bean sprouts as shown by using 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH•) scavenging activity assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method, and ferric reducing antioxidant power (FRAP) assay (p > 0.05). Additionally, the PAW treatment caused no significant changes in the total phenolic and flavonoid contents, nor the sensory characteristics of mung bean sprouts (p > 0.05). Reactive species such as nitrates, nitrites, and H2O2 were generated in PAW, which presumably contributed to the disinfection efficacy of PAW. These data show that PAW can be used as a promising nonthermal technology for the control of microbial contamination in sprouts.
Edible sprouts are common food ingredients across the world. However, sprouts can be contaminated by pathogenic microorganisms, which may result in health risks to humans. Recently, PAW has been shown to be a safe and effective method for food surface sanitation. However, the application of PAW in the microbial control for sprouts is less investigated. In this study, the influences of PAW on the microbial load, chemical and sensory quality of mung bean sprouts were investigated for the first time. The results showed that PAW could effectively inactivate bacteria and yeasts and moulds on mung bean sprouts without resulting in significant changes in the antioxidant capacities, total phenolic and flavonoid contents, and sensory characteristics of mung bean sprouts. These data indicated that PAW can be used as a promising nonthermal technology for reducing microbial populations on sprouts.
•A 30-min PAW treatment of mung bean sprouts reduced total aerobic bacterial counts by 2.32-log10 CFU/g.•PAW effectively reduced microbial loads on mung bean sprouts.•PAW had no adverse impacts on physicochemical properties of mung bean sprouts.•Reactive species played a pivotal role in the inactivation efficacy of PAW.•PAW is a promising method for the preservation of mung bean sprouts.