Evolution of the oxidative stability, bio-active compounds and color characteristics of non-thermally treated vegetable pâtés during frozen storage.

BACKGROUND: Few studies have investigated the effects of frozen storage on processed vegetables. The present study evaluates its effects on the quality characteristics of non-thermally stabilized tomato-based pâtés compared to thermally stabilized pâtés stored at room temperature. Two different types of tomato-based pâtés were analyzed in terms of bio-active compounds, as well as colorimetric parameters and oxidative degradation just after processing and also after 4, 8 and 12 months of storage.

RESULTS: Thermal treatment mainly affected the colorimetric parameters and oxidative degradation, whereas its effects on bio-active compounds became more visible and significant during storage. Freezing allowed in both pâtés to maintain significantly higher a* values than storage at room temperature, whereas brightness, which is linked to residual activities of different enzymes, varied during storage according to the ingredient formulation. During storage, oxidative degradation of the lipid fraction was more marked in the pâté containing a lower quality oil, and less marked when the absence of thermal treatment was combined with frozen storage.

CONCLUSION: Freezing could represent a viable alternative way to preserve high-quality products over time. An optimal combination of blanching, freezing rate, storage and thawing conditions will provide the best results in terms of the quality/price ratio. © 2017 Society of Chemical Industry.