Colour and chlorophyll level modelling in vacuum-precooled green beans during storage.

To investigate the changes in colour and chlorophyll levels in vacuum-precooled green beans during storage, kinetic models and shelf life prediction models of these quality indices were established by reaction kinetics and the Arrhenius equation. Linear regression analysis was used to study the changes in colour and chlorophyll levels during 12 d of storage at 0 °C, 5 °C, 10 °C and 25 °C, and the relationship between chlorophyll level and total colour difference (ΔE) was also determined. The results showed that the colour and chlorophyll levels retained in vacuum-precooled green beans were better than those in the control group during storage. A linear regression analysis revealed that the change rate constants of colour parameters (L*, a*, b* and ΔE) and chlorophyll levels followed the Arrhenius law dependence on temperature. Colour and chlorophyll levels were successfully described by zero-order and first-order reactions, respectively. In addition, the shelf life based on ΔE and chlorophyll level changes of 10% was similar to that at a cut-off score of 6 by sensory evaluation. It was suggested that the kinetics model could accurately predict the shelf life and changes of colour and chlorophyll levels in vacuum-precooled green beans during storage. • Vacuum precooling resulted in higher retention colour of green beans during storage. • Kinetics modelling was used to map green beans color changes during storage. • The applicability of the Arrhenius law during storage was investigated. • Chlorophyll was a predictor of colour quality index during storage. [ABSTRACT FROM AUTHOR]