Influence of dry and wet osmotic dehydration on colour and texture of a spread kiwi product

Development of new products which present a good organoleptic quality but also offer other advantages such as the incorporation of healthier ingredients is currently a priority in the food industry. It is also important that the elaboration method of these products is as soft as possible to preserve the maximum characteristics and nutrients of fresh fruit. In this sense, the elaboration of healthy spread fruits by osmotic dehydration is an excellent option due to the high quality of the products obtained as compared with other drying methods. Traditional wet osmotic dehydration has however some disadvantages related with the handling of big volumes of osmotic solutions. The dry osmotic dehydration might be an alternative since the volume of solution generated is considerably lower than the volume managed in the wet method and it is more concentrated in aromatic compounds, soluble vitamins and minerals as it comes from the product itself. The aim of this study was to compare the two different methods, wet and dry osmotic dehydration, as a step to produce a 30 Brix spread kiwi product formulated with two different sugars, sucrose and isomaltulose. Physicochemical parameters as well as colour and texture analyses were performed. The results showed that there was not a clear behaviour of the samples in colour terms, although less L* values were obtained for all the products compared with fresh one. On the other hand, the use of different sugars did not show significant differences either in colour terms or texture parameters. Therefore, isomaltulose can be used as an ingredient to replace sucrose in the manufacturing of this kind of products. Furthermore, since isomaltulose has less sweetener power than sucrose, the obtained product is closer in taste to fresh fruit than the product processed with sucrose.