Physicochemical characterization and label comparison among diet yogurts sold in the city of Limoeiro do Norte - CE

Abstract This work aimed at analyzing labels (based on the current legislation) and confirm the nutritional information given on the label of five brands of diet yogurt. The physicochemical analyses carried out were: moisture, minerals, proteins, lipids, reducing carbohydrates in lactose, non-reducing carbohydrates in sucrose, total carbohydrates, acidity and pH. All brands of diet yogurt had mandatory nutritional information on their label. As for content, only brands B and C are compliant with the current legal demands. The numbers found in the analyses for protein and carbohydrates were higher than the percentages shown on the labels in all brands. There were no numbers for lipids. Despite the differences found on the labels, all brands of diet yogurt are in accordance with the Identity and Quality Standards for Fermented Milk as for protein, acidity and fat content. There was a significant difference in the complementary analyses for moisture, minerals and acidity. Nevertheless, the numbers assigned to carbohydrates and protein were lower than the actual values determined in lab and, in some brands, carbohydrates were three times higher. Thus, despite presenting all the necessary information on the label, the companies are not concerned about showing the correct nutritional data to consumers.

Evaluation of Caesalpinia pulcherrima endospermic gum as affinity matrices for galactose-binding lectins interaction

Lectins are proteins or glycoproteins able to bind, specifically and reversibly carbohydrates and glycoconjugates. Considering this ability, the utilization of Caesalpinia pulcherrima seeds polysaccharides as an affinity matrix was tested. The endospermic gum were solubilized in distinct concentrations of NaOH and treated with different amounts of epichlorohydrin (ECH) forming affinity gels with variable capacity for interaction with galactose- binding lectins. The gel with an ECH/gum ration of 6.0mmol/g was selected as the best affinity matrix. The matrix presented different efficiencies in terms of isolating galactose-binding lectins. C. pulcherrima endospermic galactomannans were purified by ethanol precipitation and the purified galactomannan was crosslinked with the best formulation of gel. The Artocarpus incisa, Ricinus communis and Abrus precatorius lectins showed interactions of 11.5, 17.7 and 47.2mg of retained protein in 1g of gel, respectively; the Artocarpus integrifolia lectin showed the highest affinities (79.7mg/g). The heamaglutination assays confirmed the activity and SDS-PAGE electrophoresis confirmed the isolation of the lectins in a single-step procedure.