Physico-Chemical and Sensorial Evaluation of Guava Jam Made without Added Sugar

摘要

This research is justified by the need of using the guava production of a family agribusiness in the region of Maringá (Brazil) for the production of zero sugar guava sweet, product directed to both diabetic public and consumers interested in a diet with reduced sugar content. Our objectives were the development of zero sugar guava jam, its physical-chemical characterization and sensory evaluation, besides phenolic compounds quantification in guava fruit and guava jams. Two guava jam formulations were prepared: Standard Formulation (SF), with sucrose, and Zero Sugar Formulation (ZSF) in which sucrose was replaced by a mix of sweeteners Low?ucar Brand?. The following physical-chemical analyses were performed: pH, soluble solids (oBrix), reducing sugars, water activity, acidity, ash and moisture. The soluble solids content found for SF was 65.03°Brix while the value found for ZSF was 50.75°Brix, which is expected for diet and light jams. The replacement of sucrose with sweetener in ZSF allowed the reduction of approximately 40% in the reducing sugar content, very significant result. The values of total acidity and water activity were within recommended values to prevent syneresis and growth of pathogens. Sensory analysis was performed with 50 untrained panelists using a Paired Test, to identify the preferred formulation, in addition to a 9-point Hedonic Scale Test, to evaluate atributes of colour, aroma, flavour and texture in guava jam formulations. Results for the Paired Test revealed no significant difference between the acceptance of SF jam and ZSF jam by the panellists. We performed the quantification of phenolic compounds in guava fruit and guava jam samples by the Folin-Ciocalteau method, varying the amount and concentration of ethanol used as extractor solvent. The levels of polyphenols found in all samples were surprising, which revels potential antioxidant activity of guava fruit and guava jam.