Development of novel sanitizers for fresh vegetables
Postharvest sanitization of fruit and vegetables is important in enhancing quality and food safety. In this study, five non-chlorine sanitizers, electrolyzed water (EO), electrolyzed alkaline water (EOAl), acidified sodium chlorite (ASC), hydrogen peroxide (H2O2) and scallop powder solution (SP), were evaluated for their effectiveness in reducing resident bacteria and inoculated pathogen (Escherichia coli O157:H7) on tomato and eggplant and compared with 200 ppm chlorine solution and distilled water (control). Tomatoes had high prevalence of total viable bacteria (5.5 log CFU g‑1) and coliforms (3.3 log CFU g‑1), and were found to contain E. coli (2.4 log CFU g‑1), Staphylococcus spp. (3.8 log CFU g‑1), Listeria spp. (3.6 log CFU g‑1) and Yersinia spp. (1.7 log CFU g‑1). A similar microbial profile was obtained on eggplants. No Salmonella spp. or Vibrio spp. were detected on either vegetable. Washing tomato and eggplant in distilled water removed some soil and other debris, but did not markedly reduce the bacterial load. The different sanitizers reduced the total viable bacteria by 2.3-3.5 log CFU g‑1 and coliform bacteria by 1.1-1.9 log CFU g‑1 on tomatoes. The resident pathogenic bacteria were also reduced to below detection limit by H2O2, ASC and SP. The different sanitizers had similar effects on total viable and coliform bacteria load on eggplant. However, only H2O2 and SP reduced the pathogenic bacteria to below the detection limit. On inoculated produce, E. coli O157:H7 was higher on tomato (5.4 log CFU g‑1) than on eggplant (4.7 log CFU g‑1). Chorine, EO, H2O2 and SP had more potent effects on tomatoes than the other sanitizers. On eggplant, the pathogen was undetected in all sanitizing treatments, except EOAl. The results showed that SP and H2O2 were more promising alternatives to chlorine that could be applied in fresh produce industries.
Ahmed, S., Bari, M.L., Rahman, M.A., Goffar, M.A., Acedo, A.L., Easdown, W., Hughes, J.A. and Keatinge, J.D.H. (2017). Development of novel sanitizers for fresh vegetables. Acta Hortic. 1179, 143-148
fruits and vegetables, pathogens, scallop powder, EO water, ASC