Antibacterial effect of verjuice against food-borne pathogens

Abstract

Purpose - Nowadays, natural products are preferred for food safety and preservation due to the demand of consumers. The industrial methods which have been in use for a long period of time have had an adverse impact on organoleptic properties of foods or on human health. The purpose of this paper is to investigate the antibacterial effects of unripe grape products on natural and inoculated micro-flora of lettuce as an alternative functional and natural antibacterial agent for consumers and food industry. Design/methodology/approach - The antibacterial effects of products on initial micro-flora of lettuce were detected. The lettuce samples were treated with products for different treatment times (0, 5 and 10 min). The antibacterial effects of products against inoculated micro-flora on lettuce were obtained. Lettuce samples were separately inoculated with food-borne pathogens (similar to 4 log CFU/g) and treated with products for the same treatment periods. Findings - Unripe grape products decreased the initial micro-flora by approximately 1 log CFU/g in 5 min. Unripe grape products dramatically inhibited the inoculated E. coli on lettuce samples right after the treatment. Majority of the unripe grape products decreased the number of S. Typhimurium and L. monocytogenes to an undetectable level in 5 min. S. aureus was the most resistant microorganism among the tested cultures. It was concluded based on the conspicuous results on the inhibition of E. coli, S. Typhimurium and L. monocytogenes that unripe grape products can be considered as natural antimicrobial agents for food safety. Originality/value - This study is also valuable since it enables the in situ testing of the potential usage of unripe grape products against food-borne pathogens.