Modelling the biochemical and sensory changes of strawberries during storage under diverse relative humidity conditions

Many studies stress the importance of keeping strawberries at high relative humidity conditions during postharvest storage. However, the effect of deviations occurring across the supply chain on the appearance, acceptability and biochemical properties of strawberries has not been adequately explored or quantified to date using kinetic modelling applications. This study investigated the effect of relative humidity (RH)on degradation kinetics of quality and biochemical properties of ‘Strawberry Festival’, during 7 days of storage at 2 °C, using zero, first-order and Weibull models. The strawberries were stored at 40, 60, 70, 80 or 90% RH and were evaluated using subjective quality evaluation, weight loss monitoring and biochemical analysis. The shelf life was established based on current industry practices using subjective quality evaluation, namely shrivelling and colour scores. The Weibull model was found to better fit the experimental chemical analysis data compared to zero and first order kinetics models. The analysis of the rate constants quantified the significant effect of RH conditions on the weight loss and degradation rate of chemical components. Storage at low RH conditions accelerated the loss of ascorbic acid, and anthocyanins and negatively affect the in vitro antioxidant activity. The overall appearance of strawberries was modelled with zero-order kinetic model and the results revealed that lower RH conditions can limit the remaining shelf life of fresh strawberries by increasing the rate of appearance deterioration. Using RH and time as predictors in a logistic regression model, the waste occurring due to unacceptable strawberry quality, was predicted; highlighting the importance of using RH in predictive modelling when designing supply chains with the view to minimise losses.