Aplicação do psyllium (Plantago ovata) como substituto da pectina em geleia de abacaxi

Abstract

The production of jelly is a method of preserving fruits by the use of heat, being characterized by its low concentration of moisture and high content of solids. Allied to this is the alternative of minimizing losses, adding by-products of parts of the fruits, which may contain a greater amount of nutrients when compared to the fruit pulp.Psyllium has pectic characteristics, with a high fiber content, with 10 to 30% mucilage in its bark. Based on this, the objective of this work was to develop jam with pulp and flour from pineapple peel, with replacement of pectin by psyllium mucilage.Extra jelly formulations were prepared with0.25% psyllium (referring to the sugar mass) and 1% pineapple peel flour, which was obtained from a peel drying process for 300 minutes, followed by crushing and standardization of granulometry with 20 mesh. A standard formulation was also prepared with 50% of the fruit pulp, 50% of sugar, 1% of pectin (referring to the sugar mass) and 0.65% of citric acid (referring to the sugar mass).The formulations were prepared with reference to Good Manufacturing Practices and the standard of identity and quality ofthe jelly. For all formulations, the instrumental color measurement was obtained, whose data resembled works found in the literature. The pH of the jellies showed desirable characteristics, with higher levels being obtained for formulations added with pineapple peel flour.The same effect was observed for the content of soluble solids (°Brix) with values of 65.33 for standard jelly, 65.67 with psyllium, and 67.67 to 68.00 for formulations containing pineapple peel flour. Higher levels were also found forthe titratable acidity of jellies with pineapple peel flour. The water activity determined was in the range of 0.84 to 0.88, the lowest being obtained for formulation with psyllium.For the pineapple peel flour, the effective diffusivity coefficient of water during drying was determined, whose value was 1,51 X 10-11m2s-1with a coefficient of determination of 0.95. Finally, the rheological behavior of the elaborated jellies was compared, verifying the behavior of non-Newtonian fluid with pseudoplastic characteristics for all formulations.In addition, it was found that the addition of psyllium increased the viscosity of the jelly. Pineapple jelly with psyllium and pineapple peel flour showed good results, showing that it is feasible to substitute pectin for psyllium and reuse the by-product (pineapple peel).