Obtención y análisis de nuevos alimentos, ricos en fitoquímicos bioactivos, a partir de la granada (punica granatum l.)

Resumen

Developing novel high-quality pomegranate (Punica granatum L.) food products, rich in bioactive phytochemicals, from underused fruits may meet the needs of both consumers and producers. This was the aim of the present Doctoral Thesis, taking always into consideration the framework of the south east Spain as main European region producing pomegranates. For this reason, the phytochemical profile and quality parameters of Spanish pomegranate cultivars (¿Mollar de Elche¿ and ¿Valenciana¿) were compared with ¿Wonderful¿ ones, in order to select the most interesting properties for the development of organoleptically attractive and rich in bioactive compounds pomegranate juices. Once the phytochemical characterisation and sensorial analysis of pomegranate cultivars revealed a vast diversity among accessions and the potential of the Spanish ones was highlighted, efforts to elucidate the (poly)phenolic fingerprint of the juice from the main Spanish cultivar, ¿Mollar de Elche¿, were made. In this sense, the best analytical conditions needed to reach a high throughput and accurate non-targeted screening of (poly)phenolic compounds were identified for pomegranate juice by UHPLC-MSn. This comprehensive evaluation of the (poly)phenolic fingerprinting of pomegranate juice allowed the tentative identification of 21 phytochemicals not previously reported, extending, hence, the variety of substances contributing to the definition and to the bioactive properties of this plant food. On the other hand, basic information was provided about how thermal treatment affects browning development according to juice composition and storage conditions. Combining juice blending, thermal treatment, and storage temperature was revealed as a suitable and effective alternative to solve browning problems occurring in slightly coloured ¿Mollar de Elche¿ pomegranate juices. The array of outcomes accomplished could be used for juice industry to develop high-quality juices keeping the appealing properties of fresh juices during storage. Finally, pomegranate wine was proved to be a suitable way of industrialisation for underused fruits, leading to food products rich in phytochemicals (phenolic compounds and melatonin) with a broad range of attributed physiological functions. On the whole, the insights accomplished in this Doctoral Thesis fulfilled the needs of both consumers and pomegranate producers by developing novel high-quality pomegranate-derived food products. The significance of the bioactive phytochemicals present in these products together with other quality parameters was emphasised throughout this memory.