Unconventional technologies to steer food quality and functionality

Nowadays food processing is aimed to develop foods that are not only safe and nutritious, but also characterized by specific technological properties (structural, stabilizing, sensory) and health promoting functions. These important food functions, however, are strongly dependent on the way the foods are processed. Unconventional technologies, such as ultrasounds, high pressure, pulsed electric fields, dense phase carbon dioxide and UV light, have been investigated in order to satisfy the demand for foods able to accomplish desired technological and functional properties. This Ph.D. thesis aimed to investigate the effects of unconventional technologies on food quality and functionality of fruit and vegetable derivatives. To this purpose, selected unconventional technologies such as ultrasounds (US), high pressure homogenization (HPH) and pulsed electric fields (PEF) were applied and their effects on physical, chemical and physical chemical properties of fruit and vegetable derivatives and on in vitro functionality of bioactive compounds were investigated. The results acquired highlighted that US and HPH if properly applied, represent an efficient strategies to develop fruit and vegetable derivatives with desired quality properties. In particular, combined HPH and US treatments with in situ heat generated caused the inactivation of PPO in apple juice. Moreover, HPH and US treatments individually applied induced an increase in consistency of tomato juice with different concentration levels. However, HPH resulted more effective than US in changing tomato juice consistency. Finally, low frequency US treatments combined with in situ heat generated allowed to decontaminate wastewater from fresh-cut lettuce washing. Unconventional technologies can also steer functional properties of fruit and vegetable derivatives. In particular, HPH resulted an efficient technology to produce physical stable nanoemulsion enriched with a mixture of bioactive compounds extracted from thistle (namely silymarin). Finally, US and PEF can be applied to tomato derivatives without impairing carotenoids functionality.