| dc.description.abstract | Effects of fermentation factors including time (0, 12, 24, 36, 48, 60 and 72h),
temperature (20, 25, 30, 35 and 40 ) and inoculum volume (v/w) (0, 1, 5, 10,
15 and 20%) on the bioactive compounds of bitter gourd juice using
Lactobacillus plantarum were studied in this research. Determination of pH, total
soluble solids (TSS), total phenolic contents (TPC), antioxidant capacity (AC),
charantin content and level of bitterness were carried out. In general, the TPC
and AC values of fermented samples increased significantly (p<0.05) compared
to the control ones. In the first experiment, the TPC value of 24h-fermented
sample reached a peak of 12.12 0.03 mg GAE/ 100ml, meanwhile the highest
AC value obtained after 72h fermentation (70.88 2.30 %). In the second
experiment, the highest TPC and AC values were recorded at 40oC, with the TPC
was 13.13 0.16 (mg GAE/ 100ml) and the DPPH scavenging effect was 73.42
0.99 (%). Meanwhile in the last experiment, with 20% inoculum volume, the
highest TPC and AC values were 13.78 0.16 (mg GAE/ 100ml) and 70.93
3.12 (%), respectively. In addition, the charantin content of fermented juice
were also recorded to be significantly higher (p<0.05) than control one in all
three experiments. The values felt between 1.03 0.11 and 1.94 0.05
(mg/100ml). Through sensory evaluation test, significant differences (p<0.05) in
the bitterness among unfermented and fermented samples were also recorded.
Most of the panelists recognized there was reduction in bitterness of fermented
sample compared to the control one. To sum up, fermentation process would
significantly enhance the TPC and AC values, improve charantin content and
reduce the level of bitterness of bitter gourd juice.
Keywords: bitter gourd, charantin, Lactobacillus plantarum, juice processing,
fermentation, bitterness, sensory evaluation. | en_US |
