ABSTRACT

Nowadays there is a rising trend towards the consumption of minimally processed, due to the current needs of society. Any minimally processed product should be safe, from the microbiological point of view, and keep nutritional and sensory properties from whole fruits and vegetables. However, minimally processed products have a short shelf life which limits its commercialization.
There are many techniques to try to maintain and extend the quality and safety of minimally processed products.
Persimmon (Diospyros kaki) "Rojo Brillante" and melon (Cucumis melo L.) "Piel de Sapo" have been used in this thesis. Persimmon is characterized by its short seasonal. Moreover the recent techniques to remove the astringency have increased its production. As a consequence, it is necessary to create new ways to diversify their marketing. On the other hand, melon has a very big shape which implies remarkable difficulties to manage it. This is the reason why new forms of melon presentation are searched to offer a more convenient ready-to-eat product. Specifically in this work, the influence of different techniques in the conservation of minimally processed products such as CO2-rich atmospheres, washing with calcium lactate, passive modified atmosphere packaging along with the use of essential oils (EOs) has been studied.
The application of a CO2-rich atmosphere in sliced persimmon implied an increase in O2 consumption not only in washed with water samples but with calcium lactate. Besides it significantly reduced CO2 production.
The respiratory behavior as a function of temperature of both fresh-cut fruit was fitted accurately to a linear regression model but not to the non-linear model.
Furthermore, the combination of modified atmosphere packaging with the use of essential oils has been studied. In the case of persimmon, essential oils (lemon and thyme) were applied in a different way, either directly in the container or by dipping pieces of fruit in a solution where the essential oil was dispersed. The direct application of lemon essential oil at high concentrations had a negative effect on the antioxidant capacity and total phenol content, which could be related to a greater browning observed in these samples. However, thyme EO showed antimicrobial effect at high concentrations. 
The highest cinnamon leaf essential oil concentration applied in fresh-cut melon implied a greater antioxidant capacity.
According to the microbiological results, lemon essential oil controlled better the growth of mesophilic aerobic whereas cinnamon essential oil had better antifungal activity at high concentrations.