title: Organic acid based sanitizers and free chlorine to improve the microbial quality and shelf-life of sugar snaps.
abstract: A screening in a sugar snap packaging company showed a converged build-up of aerobic psychrotrophic plate count (APC) (ca. 6.5 log CFU/100mL), yeasts and molds (Y&M), and lactic acid bacteria (LAB) (both ca. 4.5 log CFU/100mL) in the wash water in the absence of water sanitizer, and a low build-up of chemical oxygen demand (30 ± 5 mg O2/L) and turbidity (5.2 ± 1.1 NTU). Decontamination experiments were performed in the lab with Purac FCC 80® (80% L(+) lactic acid), two other commercial water sanitizers based on organic acids (NATRApHASe-ABAV®, and NATRApHASe-FVS®) and chlorine to evaluate their performance in reduction of the sugar snap microbial load as well as their functionality as disinfectant of the wash water to avoid cross-contamination. An additional 1 log reduction of APC on the sugar snaps was achieved with lactic acid in the range 0.8 to 1.6%, ABAV 0.5%, and free chlorine 200mg/L when compared to a water wash, while no significant difference in the numbers of Y&M was obtained when washing in sanitizer compared to water. There was no significant influence of the studied concentration and contact time on decontamination efficiency. Treatment with lactic acid 0.8% resulted in a lower APC contamination on the sugar snaps than on the untreated and water washed samples for 10 days. Chlorine 200mg/L was the only treatment able to maintain the Y&M load lower than the untreated samples throughout the entire storage duration. The use of water sanitizers could not extend the sensorial shelf-life. Microbial loads were not indicative/predictive of visual microbial spoilage (shelf-life limiting factor), whereas maturity and amount of damage at the calyx end of the pods were. The APC wash water contamination (5.2 log CFU/100mL) was reduced significantly by chlorine 20 to 200mg/L (to 1.4 log CFU/100mL), ABAV 0.5 to 1.5% (to 2.7 log CFU/100mL), FVS 0.5% (to 2.7 log CFU/100mL) and lactic acid 0.8 to 1.6% (to 3.4 log CFU/100mL). Only the use of chlorine enabled the reduction of the Y&M wash water contamination significantly (from 3.4 to 1.4 log CFU/100mL). The low physicochemical build-up of the sugar snap wash water during the industrial washing process makes free chlorine attractive as a water disinfectant to prevent bacterial and fungal cross-contamination, whereas the sanitizers based on organic acids are not, due to their weak water disinfection efficiency.
authors.affiliation: Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; Laboratory of Food Microbiology and Biotechnology, Department of Industrial Biological Sciences, Faculty of Bioscience Engineering, Ghent University Campus Kortrijk, Graaf Karel de Goedelaan 5, B-8500 Kortrijk, Belgium.
authors.forename: Sam
authors.initials: S
authors.lastname: Van Haute
authors.forename: Mieke
authors.initials: M
authors.lastname: Uyttendaele
authors.forename: Imca
authors.initials: I
authors.lastname: Sampers
mesh_terms: D001419:Bacteria / Q000302:isolation & purification; D002713:Chlorine / Q000737:chemistry*; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000737:chemistry*; D004203:Disinfection / Q000379:methods; D005506:Food Contamination / Q000517:prevention & control*; D063427:Food Quality; D061353:Food Storage; D019344:Lactic Acid / Q000737:chemistry; D018532:Pisum sativum / Q000382:microbiology*; D014867:Water; D015003:Yeasts / Q000302:isolation & purification
chemical_list: D004202:Disinfectants; D014867:Water; D019344:Lactic Acid; D002713:Chlorine
keywords: Chlorine; Decontamination; Microbial quality; Organic acid; Sugar snap; Water disinfection