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The antioxidant and antibacterial activities of the phytochemical constituents of the pericarp, mesocarp and segment membrane crude ethanolic extracts of Pummelo (Citrus maxima (Burm.)) fruit were were tested against Escherichia coli and Salmonella typhimurium. Preliminary phytochemical test revealed the presence of phenols, tannins, saponins expressed as catechine quivalent (CE)/100ml and flavonoid expressed as gallic acid equivalent (GAE)/100ml. The order of which was as follows pericarp > segment membrane > mesocarp. The strongest antioxidant activity was obtained by the pericarp extract (29.64 expressed as % lipid peroxidation). The differences in the measured amount of phytochemicals and antioxidant activity among the three sample extracts were found to be significant. In terms of antimicrobial activity, the pericarp, mesocarp and segment membrane extracts generated zone of inhibitions measuring 17.10, 18.00 and 17.03 mm for S. typhimurium, respectively at 100% concentration. E. coli was noted to be inactive in all three sample extracts at 100% concentration. The capacity of E. coli to counteract the inhibitory effect of the phytochemicals contained in the pummelo extracts may be attributed to its rough corrugated cell wall and thick periplasmic space as opposed to the smooth curved and barely seen periplasmic space of S. typhimurium. However, no significant correlation was detected among the phyto-* Corresponding author. A. S. A. Barrion et al. 750 chemical content, antioxidant and in vitro antimicrobial activities of the sample extracts against S. typhimurium.

Medombae is a dried starter culture used for traditional rice wine processing in Cambodia. However, studies on the role of mold and yeast present and their efficacy for rice wine fermentation are still limited. Cultural and morphological tests revealed that the isolated representative mold strains were isolated based on the method of identification used as Mucor spp and Rhizopus oryzae. On the other hand, the biochemical properties of the first yeast isolate using the Vitek 2 identification system and YST Card identification suggests its identity as Candida tropicalis. The second yeast strain examined for its morphological and cultural characteristic using agar slide technique, and its protein profile which was compared to the reference and sample protein masses using Biomerieux Vitek MS (MALD-TOF) showed the presence of Saccharomyces cerevisiae. The biochemical characteristics and cellular characteristics of the third yeast isolate as described by Lodder (1970) and Kreger-Van Rij (1984) confirmed its identity as Saccharomycopsis spp. The DNA test of identification of the isolates should be conducted to further confirm the identity of the isolates.

The study determined the total phenolic (TP) content, antioxidant activity (AOA) and copper reduction antioxidant capacity (CUPRAC) of rice wine from waxy pigmented and non-pigmented rice varieties using traditional and multi-parallel fermentation methods with different starter cultures. The rice wine produced using waxy pigmented rice had high TP and AOA compared to rice wine produced using waxy non-pigmented rice regardless of the method of fermentation (traditional or multi-parallel). The type of starter culture had less effect on the TP, AOA and CUPRAC of the rice wines. The results of the study revealed that the rice wine produced using the Cambodian waxy rice possess bioactive compounds that could function as antioxidants, with higher values obtained from pigmented than the non-pigmented variety. Hence, this study proved that rice wine is a healthy alcoholic drink. However, future research should be conducted to identify the specific antioxidant compounds in rice wine using waxy pigmented rice.