Isolasi, Identifikasi Pigmen, dan Analisis Aktivitas Antioksidan Pigmen Monascus

Monascus is a type of organism that can produce natural pigments. Monascus pigments have been widely used in the food and pharmaceutical industries. Besides having natural pigments, Monascus also contains antioxidants as preventing of the free radicals. The purpose of this study is to isolate, identify the type of pigment, and analyze antioxidant activity. This research method is divided into 3 stages; Monascus isolation, pigment identification with UV-vis spectrophotometer and TLC, and calculation of antioxidant activity with DPPH. The isolated Monascus had 3 pigment fractions and contained a total carotenoid of 18.55 µg/g, total orange pigment of 278.25 units/mL, and red pigment of 235.75 units/mL. Antioxidant activity of 4.22 ppm and included in the high category. Key words: antioxidant; monascus; pigment.

Uji Aktivitas Antioksidan Tiga Spesies Tanaman Sarang Semut (Famili: Rubiaceae) Asal Kabupaten Merauke, Papua

Sarang semut plant is one of indigenous medicinal plants of Merauke region, the Papua province. Local people use the bulb of sarang semut plants to cure inflammation, muscle pain and enhancing immunity. However rare research of the plants has been done especially on the antioxidant activity. The objective of this research was to investigate the antioxidant activity of three species of sarang semut plants which were Myrmecodia beccarii, Myrmecodia sp. and Hydnophytum sp. The test was necessary to identify the inhibitory concentration level of plant extract in blocking a free radical (IC50). Parts of plants were extracted with maceration using methanol for 3 x 24 h to produce concentrated methanol. Plant extracts of three species were then subject to antioxidant activity test based on free radical blocking of 1,1-Difenil-2-Pikrilhidrazil (DPPH) qualitatively and quantitatively using Ultraviolet-Visible spectrophotometry. The results showed the methanol extract of M. beccarii, Myrmecodia sp. and Hydnophytum sp. were active as antioxidants with IC50 from 8.18 ppm, 21.79 ppm, 25.31 ppm, respectively while Vitamin C as a control has IC50 7.85 ppm. In conclusion, three plant species of sarangsemut are potential as natural antioxidant and plant extracts of M. beccarii showed the highest antioxidant activity among others. Key words: Antioxidant, sarang semut plants, Rubiaceae, DPPH.

Effect of α-tocopherol on in vitro culture of bovine embryos

Bovine oocytes were matured and fertilised under 5% CO2. Presumptive zygotes were co-cultured in synthetic oviductal fluid droplets, supplemented with either 0 (control), 25, 50, 100, or 200 µM of α-tocopherol. Blastocyst development rates were significantly influenced (P < 0.05) by the level of antioxidant in the culture media. Control showed a blastocyst yield of 18.46, 21.11, 27.92, and 31.66%, respectively, at α25; α50 and α100. Blastocyst yield for α200 was severely decreased, to 8.01%. An increase in overall IVF results was also observed as the concentration of α-tocopherol increased (control, 14.21%; α25, 14.35%; α50, 19.52%; α100, 21.11%), decreasing to 5.75% for the concentration of α200. The present study clearly demonstrates that α-tocopherol at a concentration of 100 µM significantly improves the proportion of oocytes that develop to the blastocyst stage. Key words: Antioxidant, α-tocopherol, reactive oxygen species, bovine, embryo

Total antioxidant capacity: A tool for evaluating the nutritional status of dairy heifers and cows

The nutritional status of dairy heifers and cows in Nova Scotia and Ontario was evaluated by measuring the total antioxidant capacity (TAC) of plasma antioxidants. Lactating cows had higher TAC levels compared to dry cows (P < 0.005). The TAC levels in cows were higher in Ontario compared to Nova Scotia (P < 0.001), and varied with changes in seasons, being highest in winter and summer in Nova Scotia and highest in the fall and spring in Ontario (P < 0.001). Key words: Antioxidant, dairy heifer

Studies on the Effect of Antioxidants on the Stability of Sesame (Sesame indicum linn.) Seed Oil During Storage

The oil extracted from sesame seed kernel was stored in white plastic containers using different antioxidants like Butyl hydroxy anisole-BHA, Butyl hydroxy toluene-BHT and propyl gallate-PG at various percentages (0.01-0.05%) at room temperature for 12 months. The results were evaluated after 2- months in terms of free fatty acid (FFA), iodine value and peroxide value . It was observed that the rate of increase in free fatty acid (FFA), was appreciably lower in all the three oils stored with 0.02% BHA, BHT and PG than those of the oils containing other percentages of 0.01, 0.03,0.04 and 0.05 of antioxidants. Among these three oils of sesame (0.02%) percentages of antioxidants, the rate of increase in free fatty acid (FFA) of the oil containing 0.02% of BHA was found to be the lowest (0.1372). The iodine values of the oils were not influenced by any antioxidants of any percentages. But the rate of increase in peroxide value of the oil containing 0.02% of BHA was also found to be significantly lower. Most significant differences in storage lives was observed in the stored oil containing 0.02% of BHA. Key words: Antioxidant, Free fatty acid, Iodine value, Peroxide value. Storage life, Fat-oxidant. DOI: 10.3329/bjsir.v43i2.967 Bangladesh J. Sci. Ind. Res. 43(2), 235-242, 2008