Preparation and evaluation of yogurt with pectin obtained from pera orange peel (Citrus

Abstract

Currently, the concern with the accumulation of solid urban residues in the environment is high. Daily, tons of orange peels are discarded in the environment, which is worrying to generate accumulation of solid urban residues and to waste valuable organic matter. The orange peel is a rich residue in soluble fibers, and the most known of them is the pectin. The work had as objectives, to extract the pectin from orange peel and to use its as gel agent in yogurt, to determine the chemistry and microbiological parameters of the product and to available his acceptance. The pectin extraction was realized in lab with citric acid solution at 3%. Yogurt samples were prepared without pectin, with pectin extracted in lab with low metoxil degree (LMP) and commercial pectin with high (HMP) and low metoxil degree. Samples of yogurt were evaluated on viscosity, syneresis, pH, total dry extract, protein, total coliforms to 30-35ºC, fecal coliforms to 45ºC, Salmonella  spp. and sensorally. From the results obtained, it was possible to observe that the viscosity of yogurt samples increased with the addition of LMP pectin. This addition in yogurt showed lower syneresis than the addition of HMP pectin in yogurt and yogurt without pectin. The presence of pectin did not change the chemistry parameters of yogurt samples. With respect to sensory attributes, it was not observed difference between the evaluated samples to consistence and appearance attributes, while to flavour attribute this difference occurred.