USE OF BANANA PEEL AS THICKENER IN PINEAPPLE JELLIES: EFFECT ON TECHNOLOGICAL CHARACTERISTICS

One way of preserving food is to produce jellies due to the use of heat and high osmotic pressure. Banana peel is a nutritious by-product that can be used to enrich jellies. This work aimed to formulate pineapple jelly replacing pectin with banana peel. Three jelly formulations were produced, the control, with 50% of fruit pulp, 50% of sugar, 1% of pectin, and 0.65% of citric acid; and formulations with 20% (F1) and 30% (F2) banana peel to replace pectin. Soluble solids content, titratable acidity, pH, color, and water activity were determined. The rheological behavior of the formulations was evaluated and the data were adjusted to the rheological models: Power Law, Bingham, Herschel-Bulkley, and Sisko. The soluble solids content ranged from 59.2 to 62.03%, and no significant difference was observed among the formulations, but in those enriched with banana peel, lower values than the recommendation of Brazilian legislation were verified. No significant differences were verified for the titratable acidity and the water activity of the different formulations and the values obtained were within the recommended by the legislation. The pH of F2 was significantly higher than the others and the control was significantly clearer than the enriched ones. Non-Newtonian behavior with thixotropic characteristics was verified for all the formulations, which were better represented by the Bingham model (R2>0.9) for ascending and descending curves. The values of the initial shear stress ranged from 10.010 (F1, descending curve) to 106.580 (control, ascending curve) Pa; and the plastic viscosity ranged from 3.813 (F1, ascending curve) to 10.606 (F2, descending curve) Pa·s. This suggests thinning of the formulations during flow, which can result in energy savings for this operation. Banana peel presented the potential to replace pectin in the manufacture of pineapple jelly, pointing to the feasibility of reusing this by-product.