Physical-chemical changes during extraction and clarification of guava juice

Pink guavas from Ibiapaba plateau (Serra Grande) in Ubajara country, CE, Brazil, were mashed and the pulp treated with 600 ppm of a pectic enzyme at 45 °C for 120 min. The pulp so-treated was pressed to give an average juice yield of 84.70%. The pressed juice was cloudy and pink in colour but, after addition of fining agents and filtration, a clear juice with a light yellow colour was obtained. This clear juice was preserved by the Hot-pack method. During the extraction and clarification of the juice, some of the important physical and chemical changes were followed by measuring changes in total soluble solids (oBrix), acidity, viscosity, total phenolics content, colour, turbidity and ascorbic acid retention.