PHYSICAL-CHEMICAL CHARACTERIZATION AND ANTIOXIDANT POTENTIAL OF PERSIMMON PULP (Diospyros kaki L.), cv. Rama Forte

The development of new products with extended shelf life using persimmon (Diospyros kaki L.), cv. Rama Forte becomes important, especially in the southeast region of Brazil, where the production of this fruit is concentrated and it is observed a significant post-harvest loss, thus generating an economical and environmental problem. This waste is related to quality decrease and depreciation characterized by skin darkening, loss of firmness and rapid changes in pectic fractions during ripening. In addition to the high perishability of this fruit, as the harvesting season is short, the excess production of the fruit complicates stages of transportation and commercialization. Moreover it is observed a difficulty in the consumption of persimmon derived products during off-season. There is an increase in the number of evidence supporting the assumption that fruits contain numerous bioactive molecules that prevents various disorders such as cardiovascular diseases, atherosclerosis, diabetes, cancer, among other age-associated conditions. Among these, special interest has been dedicated to antioxidant compounds from various natural sources. In this sense, studies that evaluate the bioactive potential of persimmon are important for functional products and process develop using this fruit as an ingredient. The aim of this work was to process and evaluate an antioxidant pulp based on persimmon fruit. Persimmon was purchased in local market from Rio de Janeiro which it was properly sanitized and processed. Chemical composition, total dietary fiber and total soluble solids were determined. Phenolic compounds determination was based on Folin Ciocalteu method and the antioxidant capacity was measured using the ferric reducing ability of plasma (FRAP) and the ABTS Decolorization Assay. The colorimetric profile of this pulp was determined using the Konica Minolta CR-400 digital colorimeter. It was investigated thermotolerant coliforms and Salmonella sp, according to current Brazilian legislation. The pulp was found to contain 81.1; 0.49; 0.76; 0.35g/ 100g of moisture, ash, protein and lipid, respectively. Persimmon pulp presented high amount of carbohydrates (17.3g/100g) and total dietary fiber was 1.87 g/100g. Total soluble solids was 15.3 ºBrix. Phenolic determination presented 76 mg of EAG/ 100g. Antioxidant analysis revealed 527 µmol of Fe+2 eq./ 100g and 753 µmol of EAG/g for FRAP and ABTS methods, respectively. Luminosity (L*), a* and b* values were found to be 50.48; 14.14 and 37.57, respectively. Chroma (C*) is defined as a measure of color intensity or saturation and for persimmon pulp this value was of 40.14. For microbiological parameters, the pulp was in accordance with current legal microbiological standards: < 3 MPN/g for thermotolerant coliforms and absence of Salmonella sp in 25g of product. Results suggest that persimmon pulp is an interesting source of phenolic compounds with a prominent antioxidant potential when compared to several regularly consumed fruit. Therefore, the use of persimmon pulp as an ingredient to other processes may be an interesting technological strategy to maintain the bioactive compounds and diminish the postharvest loss of this fruit. Thus, further work is ongoing in order to evaluate and incorporate other bioactive molecules in this product.

Financial support:

Acknowledgments to CAPES, CNPq, FAPERJ, UNIRIO and UERJ for financial support.