title: A predictive model for assessment of decontamination effects of lactic acid and chitosan used in combination on Vibrio parahaemolyticus in shrimps.
abstract: Vibrio parahaemolyticus is a major causative agent of human gastroenteritis in seafood products including shrimps. Lactic acid and chitosan are natural antimicrobials for food decontamination in the washing process of seafood. In this research, a 4-factor response surface model based on the Box-Behnken experimental design was developed to evaluate the effects of lactic acid (1%, 2%, and 3%, v/v), chitosan (0.4%, 1%, and 1.6%, w/v), rotational rate (90, 110, and 130 rpm) and washing time (10, 20, and 30 min) on reduction of V. parahaemolyticus inoculated in raw shrimps. These treatments achieved 2.2 to 4.3 log10 CFU/g reduction of V. parahaemolyticus in shrimps. Stepwise stratification led to a simplified model that has a satisfactory performance as evidenced by statistical indices (R(2) = 0.92; p<0.0001; RMSE = 0.196) and external validation parameters [bias factor (Bf) = 1.01; accuracy factor (Af) = 1.05]. The model generated an optimum treatment combination (3% lactic acid, 1.6% chitosan, and rotational rate at 110 rpm) that could achieve greatest bacterial reduction of 4.5 log10 CFU/g. Among the four factors, lactic acid and chitosan were the major contributors for bacterial decontamination. Analysis of variances showed a significant interactive inactivation effect (p<0.05) from combined use of lactic acid and chitosan. The treatments did not have adverse effects on the quality attributes such as color and pH of the shrimps.
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Weihuan
authors.initials: W
authors.lastname: Fang
authors.forename: Abani K
authors.initials: AK
authors.lastname: Pradhan
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D048271:Chitosan / Q000494:pharmacology*; D015169:Colony Count, Microbial; D005506:Food Contamination / Q000517:prevention & control*; D005516:Food Microbiology; D063427:Food Quality; D019344:Lactic Acid / Q000494:pharmacology*; D008962:Models, Theoretical; D017747:Seafood / Q000382:microbiology; D012758:Shellfish / Q000382:microbiology*; D014736:Vibrio parahaemolyticus / Q000187:drug effects*
chemical_list: D019344:Lactic Acid; D048271:Chitosan
keywords: Chitosan; Lactic acid; Response surface model; Shrimp decontamination; Vibrio parahaemolyticus