Nonthermal Plasma–Liquid Interactions in Food Processing: A Review

Abstract

Nonthermal processing methods are often preferred over conventional food processing methods to ensure nutritional quality. Nonthermal plasma (NTP) is a new field of nonthermal processing technology and seeing increased interest for application in food preservation. In food applications of NTP, liquid interactions are the most prevalent. The NTP reactivity and product storability are altered during this interaction. The water activated by NTP (plasma‐activated water [PAW]) has gained considerable attention during recent years as a potential disinfectant in fruits and vegetable washing. However, detailed understanding of the interactions of NTP reactive species with food nutritional components in the presence of water and their stability in food is required to be explored to establish the potential of this emerging technology. Hence, the main objective of this review is to give a complete overview of existing NTP–liquid interactions. Further, their microbial inactivation mechanisms and the effects on food quality are discussed in detail. Most of the research findings have suggested the successful application of NTP and PAW for microbial inactivation and food preservation. Still, there are some research gaps identified and a complete analysis of the stability of plasma reactive species in food is still missing. By addressing these issues, along with the available research output in this field, it is possible that NTP can be successfully used as a food decontamination method in the near future.

Antimicrobial effects of airborne acoustic ultrasound and plasma activated water from cold and thermal plasma systems on biofilms

“…H 2 O 2 is considered to be a potent anti-microbial agent. Several studies have investigated about the importance of H 2 O 2 to the antimicrobial activity of PAW 18,25 . In this study, concentration of H 2 O 2 was generated in PAW.…”

“…Plasma has been mainly used in bio-medical, textile and polymer industries 14 – 16 . However, recent studies have demonstrated potential applications of plasma technology in the food industry 17 , 18 . There is a range of different approaches to generate plasma discharges, using different geometry configuration.…”

Effective pretreatment technologies for fresh foods aimed for use in central kitchen processing

“…In addition, the reactions between newly formed species results in a decrease in the pH; the synergistic effect of high oxidation-reduction potential and low pH has proved to be the basis of the bactericidal properties of PAW. 56,57 Figure 3 shows the decontamination mechanism of PAW. 57 In an exemplified study, Ma et al 58 observed that the total number of S. aureus in PAW-treated strawberry decreased by 1.6-2.3 log.…”

“…56,57 Figure 3 shows the decontamination mechanism of PAW. 57 In an exemplified study, Ma et al 58 observed that the total number of S. aureus in PAW-treated strawberry decreased by 1.6-2.3 log. After 4 days of storage, S. aureus on the strawberry was still 1.7-3.4 log lower than that on the untreated strawberry.…”

Germination of Wheat Seeds Exposed to Cold Atmospheric Plasma in Dry and Wet Plasma-Activated Water and Mist

“…4 In agriculture and food processing, CAP has been applied to different biosubstances directly or through plasma-activated media such as water or water mist to increase productivity or fight diseases and pathogens. 5,6 Wheat is one of the most strategic crops for increasing food security, 7 and CAP has been revealed as a valuable method for enhancing wheat seed germination. 8,9 During wheat seed plasma treatment, CAP by its uniform behavior can replace traditional presowing treatment, either physically or chemically.…”