Processing of carbonated oriental pear juice (Pyrus pyrifolia var. Phatanak)
1999
Rattana Attabhanyo | Naiyatat Poosaran | Ruchira Phattharakunwanit | Aphon Charanrattanasi | Sanit Niraphat (Chiang Mai Univ., Chiang Mai (Thailand). Faculty of Agro-Industry)
Comparison of pear juice prepared from 21 weeks pear (after of full bloom) stored at 1 deg C for one week and ripened at 20-2 deg C for 4-5 days with juice prepared from fresh fruit gave higher significantly amount of reducing sugar and more preference than fresh pear juice (P0.05). The selected extraction method for preparation of carbonated pear juice was lye peeling for 3 min and cut into quarters soaking in mixture of potassium metabisulphite and citric acid 1000 mg/lit for each. During crushing, potassium metabisulphite and ascorbic acid 200 and 300 mg/lit were added respectively, then 0.005 percent (w/w) of pectinase was added into pear juice incubated at room temperature for 90 min and hydraulic press at 5 metricton. Pressed juice was heated up to 90 deg C for 90 second to stop enzymatic reaction. The optimal condition for clarified pear juice were investigated. It was revealed that the optimal condition for clarification was as follow:- 100 mg/l of enzyme, incubation at 45 deg C for 1 hour. By using 2**(2) + 2 cp factorial design, effects of B/A ratio and carbonation level of carbonated pear juice were investigated. It was revealed that B/A ratio of 56 and carbonation level of 3.4 were significant different (P (0.05). Storage of carbonated pear juice at 5 and 37 deg C for 14 weeks, it was found that colour value L, total acidity and reducing sugar before inversion increased along with time. However, volume of carbondioxide and pH value were stable. No microorganism was found during storage for 14 weeks at 5 and 37 deg C. No difference of preference between carbonated pear juice stored at 5 deg C and storage at 37 deg C (P (0.05)
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This bibliographic record has been provided by Thai National AGRIS Centre, Kasetsart University
