Effect of processing and accelerated storage on the volatile composition and sensory profile of a tomato soup

Abstract

The volatile and sensory profile of pasteurized (95°C, 18 min) and sterilized (120°C, 14 min) tomato soup and its changes at accelerated storage conditions (37°C and 42°C) were identified, characterized, and correlated by predictive models. Sterilization led to more profound changes over storage compared to pasteurisation, showing enhanced levels of 'dark' odour, 'burnt' flavour, and 'complexity', while pasteurized soup had more pronounced 'green' odour, 'vegetables' flavour, 'harmony', and 'freshness'. Over time, 'dark' and 'burnt' significantly increased for sterilized soups, whereas 'green' decreased significantly only for sterilized soup stored at 42°C. The changes of 'dark', 'green', 'off-flavour', 'burnt', 'harmony', and 'freshness' were associated with formation of furans (furfural and 2-acetyl-5-methylfuran), and decline of unsaturated aldehydes like E-2-octenal and E,E-2,4-heptadienal. These compounds were identified to represent potential shelf-life markers, yet more studies on their odour activity in the tomato soup matrix are necessary to understand their contribution to the sensory quality. The construction of partial least squares models allowed the prediction of 'green', 'off-flavour', 'burnt', and 'freshness' based on selected volatiles. These models will be important tools in the process of predicting the end of shelf life, but need to be supplemented with consumer acceptability levels.