Mathematical model for analyzing the effect of storage conditions on the visually perceived freshness of strawberries via surface luminance distribution

Abstract

Recent psychophysical experiments have revealed that the skewness of the luminance distribution on the surface of strawberries is a key parameter of their visually perceived freshness. However, the relationship between storage conditions and the resulting luminance distribution is yet to be detailed. This study investigated the effects of several storage temperature and humidity conditions on the skewness using the Weibull model. The results show that the temperature did not affect the skewness under the high-humidity condition, while under the low-humidity condition the effects of temperature became apparent. A high correlation exists between the luminance distribution and mass loss rate (via water evaporation), with skewness primarily being influenced by humidity. The protocol of the mathematical analysis is useful not only for determining the impact of humidity and temperature on strawberry freshness but also other storage conditions.