Enhancement of pomegranate juice quality through the combination of thermal treatments and blending with lemon juice

Consumer acceptance of healthy food is subordinated to quality and sensory properties. Nevertheless, red fruit juices can display unpleasant and unacceptable brown colour because of thermal treatments. As an attempt to solve these browning problems in pomegranate juices, the effect of two different heat treatments on the phytochemical composition and colour parameters of pure and blended juices was assessed through storage. Mollar de Elche varietal juice was mixed with lemon juice in order to assess the effect of blending on Mollar de Elche preservation. Juices were heat treated at 65°C for 30 s (LTLT pasteurization) or 90°C for 5 s (HTST pasteurization). Colour parameters and bioactive phytochemicals (individual anthocyanins and vitamin C) were monitored. Blended juices showed a protective effect on colour even though high falls in anthocyanins were recorded. Vitamin C was kept in those juices containing lemon but not in pure pomegranate juices. Heat processing had a remarkable effect on the blend of pomegranate with lemon as LTLT-treatment preserved the bioactive composition much better than HTST. Overall, blended juices protected juice characteristics in a greater extent than Mollar de Elche juice.