Total amino acids concentration as a reliable predictor of free chlorine levels in dynamic fresh produce washing process. (15th January 2021)

• Record Type: Journal Article
• Authors: Abnavi, Mohammadreza Dehghan; Kothapalli, Chandrasekhar R.; Srinivasan, Parthasarathy
• Is Part Of: Food chemistry. Volume 335(2021)
• Publication Date: 2021-01-15
• Subjects: Fresh produce washing process -- Free chlorine decay -- Total amino acids concentration -- Apparent reaction rate -- Mathematical modeling; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2020.127651
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: First in situ apparent reaction rate between free chlorine and amino acids during fresh produce wash. Deterministic model can be used predictively for a variety of fresh produce. Reaction rate of chlorine with amino acids in our model is robust to scaling effects. Potential to use our model to optimize free chlorine efficacy at industry scale. Abstract: We establish the total amino acids (AA) concentration in wash water as an alternative indicator of free chlorine (FC) levels, and develop a model to predict FC concentration based on modeling the reaction kinetics of chlorine and amino acids. Using single wash of iceberg lettuce, green cabbage, and carrots, we report the first in situ apparent reaction rate β between FC and amino acids in the range of 15.3 – 16.6 M −1 s −1 and an amplification factor γ in the range of 11.52–11.94 for these produce. We also report strong linear correlations between AA levels and produce-to-water ratio ( R 2 = 0.87), and between chemical oxygen demand (COD) and AA concentrations ( R 2 = 0.87). The values of the parameters γ and β of the model were validated in continuous wash experiments of chopped iceberg lettuce, and predicted the FC ( R 2 = 0.96) and AA ( R 2 = 0.92) levels very well.