The present work was undertaken with an objective to evaluate the impact of temperature on respiration rate of fresh black carrot using a non-linear enzyme kinetics approach. Two different models viz. Arrhenius equation (temperature effect) and enzyme kinetics (effect of temperature and headspace concentration) have been compared for predicting the respiration rate of black carrot. The respiratory behavior of black carrot was assessed using closed system technique at 5, 10 and 15 °C (± 1 °C) temperature and constant relative humidity (RH) of 85%. The O2 consumption and CO2 evolution rate values were 39.17, 58.88 and 68.08 ml kg-1 h-1; 22.15, 34.63 and 41.86 ml kg-1 h-1 after the attainment of steady-state condition at 5, 10 and 15 °C, respectively. The inhibition by evolved CO2 was found to be predominantly competitive at all temperatures. The average absolute deviation in O2 consumption and CO2 evolution rate for Arrhenius model was 3.5% and 5.3% while for enzyme kinetics model was 8.8% and 6.3%, respectively. Dependency of respiration rate of black carrot on temperature was well defined by Arrhenius model. The outcomes of the study can be further utilized to design the MAP (modified atmosphere packages) for fresh black carrot storage at 5 °C with 85% RH.
Keywords: Arrhenius equation; Black carrot; Enzyme kinetics model; Headspace concentrations; Modified atmosphere packaging; Respiration rate.
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