OPTIMIZING THE PECTIN EXTRACTION PROCESS FROM AMBERALLA PEEL BY THE COMBINED OXLALIC ACID AND MICROWAVE AND COMPARISON OF CHARACTERISTICS WITH THE PECTINS OBTAIN TO TRADITIONAL EXTRACTION METHOD.

The extraction of high-methoxyl pectin from amberella peels was studied. The best result was obtained with pH of 4.6, solid-liquid ratio of 1:38, extraction time of 9 min and microwave power of 600W in which the pectin content was 20%. Some characters of pectins were estimated. Pectins obtained by the combined oxalic acid and microwave showed DE value and galacturonic acid 7.3% and 100.6%; respectively, higher than those treated with hydrochloride acid. DA values were the same between both pectin samples. The lightness of pectins extracted by the combined oxalic acid and microwave was more suitable for food application than that of pectins obtain to the hydrochloride treatment. There were significant different in color co-ordinates between the pectins from hydrochloride treatment and that from the combined oxalic and microwave treatment. The viscosity and viscosity-average molecular weight of pectins of the combined oxalic acid and microwave were 120% and 161% higher than those of traditional method. Microwave irradiation could be damaged more cell walls of amberella peels to release a large amount of pectins and to reduce treatment time for minimizing the cost of extraction process. The combined oxalic acid and microwave is a good method to get more pectins from amberella peels. [ABSTRACT FROM AUTHOR]