| dc.description.abstract | Effects of processing methods including pressing, enzyme-assisted extraction
using Pectinex, lactic acid fermentation by Lactobacillus acidophilus, and alcohol
fermentation by Saccharomyces cerevisiae on total and soluble oxalate contents
of carambola juices were studied. Total and soluble oxalates were extracted by
HCl 0.2M and Nanopure water, respectively for 20 min at 800C. The extracts
were analyzed using ion exchange HPLC.
An increase in juice yields (15.89 – 17.29%), as well as total oxalate (1.60 –
1.73 times) and soluble oxalate contents (1.16 – 1.49 times) were observed in
enzymatic juices processed at different incubation periods, compared to pressed
juice. At the same time, extension of enzyme incubation periods led to an
increase in soluble oxalate contents in the products (p<0.05). The lowest and
highest soluble oxalate contents were found to be 94.56 ± 2.71 (mg/100mL)
after 90 min, and 120.85 ± 3.67(mg/100mL) after 180 min, respectively.
Alcohol fermentation using Saccharomyces cerevisiae resulted in significantly
lower amounts of total oxalate (37 – 58%) and soluble oxalate (39 - 59%) after
1–5 weeks of fermentation (p<0.05). Moreover, prolonged fermentation
demonstrated better reduction of oxalate contents. Meanwhile, lactic acid
fermentation using Lactobacillus acidophilus had no effects on total and soluble
oxalate contents in carambola juices.
Keywords: carambola, oxalate, Lactobacillus acidophilus, Saccharomyces
cerevisiae, pectin, pectinase, juice processing, fermentation. | en_US |
