Comparison of juice extraction methods, determination of bittering principles and standardization of debittering of lime juice

Abstract

In spite of good yields, high vitamin C content, nutritional and medicinal values, lime (Citrus aurantifolia Swingle is not commercially exploited due to the presence of bittering compounds. The present investigations were therefore, aimed at reducing the bitterness of juice for preparation of concentrate. Out of the different methods of juice extraction tried, screw type juice extractor was found to be the most effective with respect to high juice yield (57.75 %) and quality. The lime juice
extracted through screw type juice extractor contained 0.50 % recoverable oil, 23.24 ug/mL limonin and 47.21 ug/mL naringin. Among the various treatments tried for debittering of lime juice, use of absorbent XAD-16 resulted in a considerable reduction in bitterness. The XAD-16 resulted in 70.45 % reduction of limonin content and 72.07 % reduction in naringin content, thereby, lowering them to 5.91 and 11.71 ug/mL, respectively. Nutritionally, maximum ascorbic acid retention (25.0 mg/100 mL) was observed in XAD-16 treated juice, while non-significant change occurred in total soluble solids and acidity of treated juice. On the basis of sensory evaluation, the juice treated with XAD-16 was adjudged the best in extent of debitterness, taste, body, and flavour among all the treatments tried. However, a slight decrease in colour score was obtained that could be adjusted easily during processing.