Correlations between subjective quality and physicochemical attributes of fresh fruits and vegetables

• Subjective quality attributes are significantly correlated with physicochemical attributes.
• Rating scales are reliable in estimating physicochemical attributes of fruits and vegetables.
• Strawberry color chart can be used to evaluate sensory quality and as a quality control tool.

Color charts and rating scales have been developed for several fresh fruits and vegetables (FFVs) but limited information is available regarding the correlation between subjective evaluations and physicochemical attributes. The objective of this work was to correlate subjective quality data with quantitative analytical data collected for several fruits exposed to different environmental conditions. Avocados, blueberries, peppers, strawberries and tomatoes were exposed to a range of different temperatures and humidity conditions for varied periods of time, and quality evaluated using both rating scales and physicochemical analysis. The strength of the relationship between variables was measured using the Pearson correlation coefficient (r) and the coefficient of determination (r2) and, the significance of the relationship was expressed by probability levels (p = 0.05). Overall, there was a significant correlation between most of the subjective quality attributes evaluated and the physicochemical analysis performed. Subjective color was significantly correlated with hue angle for all fruits evaluated except for blueberries for which subjective color had a stronger correlation with L* values. Correlations between subjective color and anthocyanins, ascorbic acid or chlorophyll contents were also significant. Shriveling or stem freshness was strongly correlated with weight loss whereas subjective firmness was significantly correlated with instrumental texture. Results from this work showed that subjective quality evaluations using rating scales can be a reliable and simple method to estimate changes in color, softening, water loss, and ultimately changes in specific chemical components when FFVs are exposed to different environmental conditions. A color chart is proposed for the visual evaluation of strawberry quality.