Comparative Study Of Malt Vinegar Quality From Homnin And Kam (Oryza Sativa L.)
The aim of the research was to investigate the optimal condition for malt vinegar production from Thai rice
cultivars (Oryza sativa L.), black waxy rice (Kam) and black non-waxy rice (Homnin). The production of rice malt vinegar
consisted of 3 stages. Firstly, study of the starch conversion to sugar by mashing process using the modified procedure of
wort preparing for beer production. Then, study of the sugar conversion to alcohol in 4 days that showed alcohol content of
6.98% and 6.42%, respectively. Finally, study of the alcohol conversion to acetic acid for 30 days that showed amount of
acetic acid content of 4.5% and 4%, respectively. The bio-functional compounds’ contents Kam and Homnin rice malt
vinegar were analysed and compared to commercial malt vinegar (5.12% acetic acid). The results showed that Kam malt
vinegar had the highest content of phenolic (105.14mg GAE/100ml) and antioxidant activity (62.99%), whereas Homnin and
commercial malt were at the same level. The GABA contents in Kam, Homnin and commercial malt vinegar were 9.04, 8.61
and 12.05 (mg/100ml), respectively. The free amino nitrogen (FAN) contents were157.81, 142.31 and 125.87 mg/L,
respectively. However, the vitamin B1 content in the 3 finished products was mostly the same (average 20.39 mg/100ml).
Moreover, the flavonoid content in Kam malt vinegar was higher than Homnin and commercial malt. Therefore, Kam rice
malt has high potential for use as raw material for malt vinegar production.
Keywords - malt vinegar, rice malt vinegar, bio-functional compounds.