Optimization of Hydrothermodynamic Technology for Blueberry Food Processing

Abstract

Traditional processing technologies can negatively affect polyphenolics of blueberry products. Optimization of hydrothermodynamic (HTD) processing has been used to minimize blueberry-based product quality degradation. Preliminary experiments have shown that the quality of HTD blueberry purée in terms of anthocyanin concentration and tannin content was significantly higher than that of most commercial blueberry products. HTD technology provided pasteurization with significantly lower losses of anthocyanins as compared with conventional heating. Screening of the factors has shown that holding time, temperature of pasteurization and heating rate were significant, while cavitation mode was non-significant. Response surface methodology was used to determine an optimal combination of temperature and time (92 to 95°C with holding time 0.5 to 2.0 min). Non-linear regression analysis of the shelf-life data has provided fitted models which could be used to predict changes in anthocyanin concentration and tannins for different storage periods at 4°C and at room temperature (20 to 25°C).