Utilização do psyllium (Plantago ovata) como substituto da pectina em geleia de frutas vermelhas com hibisco

Abstract

Jelly production is a method of preserving fruit, using sugar, heat, and acidity and pH control to create unfavorable conditions for the growth of microorganisms. Psyllium, besides being characterized as a plant rich in fiber, also contains 10% to 30% mucilage in its husk, serving as an alternative to pectin in jellies. This study aimed to develop a red fruit and hibiscus jelly by replacing pectin with psyllium. A standard formulation was developed with 30% fruit, 20% hibiscus infusion, 50% sugar, 1% pectin (relative to sugar mass), and 0.65% citric acid (relative to sugar mass). Four additional formulations (F2, F3, F4, and F5) replaced pectin with psyllium at concentrations of 0.05%, 0.1%, 0.15%, and 0.20%. The physicochemical results demonstrated significant variations in pH, soluble solids content, and titratable acidity. Formulations F2 and F3 had lower pH values compared to the other formulations, while F1 had the lowest titratable acidity value. Colorimetric analyses revealed changes in color parameters, with F2 and F4 being the lightest and F5 being the darkest and reddest. For the texture analysis, differences were observed between the formulations, with F1 (1% pectin in relation to the sugar mass) showing the highest hardness, cohesiveness, and adhesiveness. The rheological behavior of the jams was described by mathematical models, with F2 showing the best fit for Bingham and Herschel Bulkley (rise) and Herschel Bulkley (descent); F3, to the Ostwald de Waelle model for rise and fall; F4 showed good fits for most of the applied models, however, it was best fitted to the Herschel Bulkley model (rise) and the Ostwald de Waelle model (descent); and F5 showed good fits for most models, however, it was best fitted to the Herschel Bulkley model (rise) and the Ostwald de Waelle model (descent). Considering the physicochemical, rheological, and nutritional characteristics, the formulation made with 0.05% psyllium (F2) presented itself as an interesting alternative to the replacement of industrial pectin, since it showed good results and a texture with a lower hardness value, with the advantage of maintaining the characteristics of the jam.