Application of micro-nano bubbles combined with sanitizers for washing process of leafy vegetables

Name: Pitirat Klintham

LCSH: Kasetsart University -- Dissertations. Ph.D. (Food Science) 2017

Classification :.LCCS: TP443

LCSH: Kasetsart University. Department of Food Science and Technology -- Dissertations

LCSH: Edible greens -- Sanitation

LCSH: Vegetables -- Sanitation

LCSH: Vegetables -- Contamination

LCSH: Microbubbles -- Utilization

LCSH: Food contamination

Abstract: Increasing incidences of foodborne outbreaks which associated to the consumption of fresh produce have been reported for many decades. Washing process of fresh vegetables is a crucial step to reduce the microbial contamination for fresh produce. This study aims to develop the washing process in order to eliminate the contamination of pathogen in fresh vegetables. The effectiveness of the fine bubble technology combined with three sanitizers including acidic electrolyte water, chlorine dioxide and sodium hypochlorite were determined. Escherichia coli and Salmonella Typhimurium contaminated on sweet basil (Ocimum basilicum Linh) and Thai mint (Mentha cordifolia Opiz.) were used as a test models. Microbubbles and nanobubbles in water were compared based on different size and their stability. Firstly, physicochemical characteristics of bubbles were investigated. The average diameter of microbubbles and nanobubbles measured by laser diffraction technique with image analysis and dynamic light scattering method were 40-60 µm and 200- 600 nm, respectively. The zeta potential of nanobubbles was minus 27 mV. Longer stability of nanobubbles was shown. Then the effectiveness on bactericidal was examined. Microbubbles and nanobubbles exhibited some effectiveness on bacterial deteachment, but the decontamination was enhanced by the combination with sanitizers. The reduction of Salmonella Typhimurium and Escherichia coli on inoculated sweet basil and Thai mint were 99.0-99.9%, when bubbles combined with acidic electrolyte water at concentration of 40 mg/L (pH 2.6, ORP ~1200 mV, Cl 40 ppm) or sodium hypochlorite at 80 mg/L (pH 6.8, ORP ~990 mV, Cl 80 ppm). Additional pre-washed with 0.1% v/v of 4 types of surfactant including sodium lauryl ether sulfate, sucrose laurate, citrus oil with glycerin solution and polysorbate 80 were also investigated. The optimum condition was two steps washing: pre washed with sucrose laurate for 3 minutes followed by 40 mg/L of acidic electrolyte water for 5 minutes with shaking at 60 rpm. Treatment was effective in reducing Salmonella Typhimurium and Escherichia coli on sweet basil and Thai mint by 99.0- 99.9% reduction. Cross contamination could also prevent in wash water. Furthermore, two step washing exhibited the reduction of pesticide residue (chlorpyrifos and profenofos) by 50-70% on sweet basil, Thai mint and Chinese kale, and did not affect the appearance quality of these vegetables.

Kasetsart University. Office of the University Library

Address: Bangkok

Email: tdckulib@ku.ac.th

Name: Warapa Mahakarnchanakul

Role: Thesis Advisor

Name: Sasitorn Tongchitpakdee

Role: Thesis Co-Advisor

Name: Wannee Chinsirikul

Role: Thesis Co-Advisor

Created: 2017

Modified: 2023-06-23

Issued: 2023-06-23

วิทยานิพนธ์/Thesis

application/pdf

URL: https://kasetsart.idm.oclc.org/login?url=https://www.lib.ku.ac.th/KUthesis/2560/pitirat-kli-all.pdf

CallNumber: TP443.P58

eng

DegreeName: Doctor of Philosophy

Level: Doctoral Degree

Descipline: Food Science

Grantor: Kasetsart University

©copyrights Kasetsart University

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