Evolution of the nutritional composition of Hovenia dulcis Thunb. pseudofruit during the maturation process

Introduction. Native to Asia, Hovenia dulcis Thunb. (Rhamnaceae), known as Japanese grape, is also found in central and southern America, southern Europe and North Africa. The fruit is a small capsule, attached to peduncle or pseudofruit, which, when mature, is the edible part. In order to increase knowledge about the potential of these pseudofruits as an alternative to other fruits available in the market, or as a new ingredient for the food industry, this study aimed to characterize the nutritional value of H. dulcis peduncles harvested at different stages of maturation. Materials and methods. Samples of H. dulcis pseudofruit were collected for five months, from an immature stage to a senescent one (Hd01, Hd02, Hd03, Hd04 and Hd05), in Curitiba, Parana, Brazil. Analysis of moisture, ash, minerals (Ca, Mg, Na, K, Fe, Cu, Mn and Zn), proteins, lipids, vitamin C, available carbohydrates, soluble sugars and dietary fiber (soluble and insoluble) were performed. Analysis of variance (ANOVA) followed by Duncan's test were applied to the analytical results. Results and discussion. Soluble sugar content increased during maturation, probably due to starch hydrolysis and water loss. This product (Hd02 to Hd05) can be considered an interesting source of dietary fiber, according to Brazilian and European regulations. Total ash content increased during the development of these pseudofruits, due to the concentration of minerals, by reducing moisture in the mature product. Conclusion. Together with fibers, Cu, Ca and Mn were the most relevant dietary contributions of mature H. dulcis peduncles, being a good means to improve the nutritional quality of modern diets, requiring further investigation of their sensory and nutritional characteristics.