Properties of flour from blanched tubers of two water yam (Dioscorea alata) cultivars were compared with those from the non blanched ones. The results showed that the proximate composition of flours from the yellow cultivar was different from that of the purple cultivar. Steam blanching (97±2°C, 7 min) on the purple cultivar resulted in more significant reduction on yield and the Lightness (L) value. However, it had significant effect on some components of the flours such as protein, ash, amylose and fiber. Results of proximate composition showed crude fat yellow and purple water yam ranging from 0.4 to 0.55%, crude protein 5-8%, dietary fiber 16-26% and starch 41-76%. Starch granule size between 20-40 µm. Blanched yellow water yam flour has the highest water and oil absorption which is 2.02 and 1.18 g/g. Dioscorine and water soluble polysaccharides, bioactive components from Dioscorea, of purple water yam flour are larger than the yellow flour. Purple water yam flour is better to be proceed as a functional food because it has a high peak viscosity, more stable to heat and has greater content of bioactive compounds. Steam blanching decrease the yield of dioscorine and water soluble polysaccharide.

As the highest yield crop worldwide, citrus peels that possess bioactive compounds were discarded as a futile by-product. Ultrasonication with environmentally friendly solvent (50% ethanol and ddH 2 O) were used in the present study to extract flavonoids from Citrus depressa Hayata peels with extraction period and fruit maturity as other variables. DPPH scavenging activity was investigated. Qualitative flavonoid content analysis was done by UV/Vis and FTIR-ATR spectra. Quantification of flavonoid using LC-MS/MS found that solvent type, fruit maturity, and ultrasonication period significantly affect the extracted flavonoid yield (p < 0.05). Extraction using 50% ethanol showed a higher yield than ddH 2 O. Flavonoid content was also higher in unripe than ripe samples. Nobiletin, tangeretin, and rutin were dominant among the identified compounds in all sample treatments. Flavonoid content in Citrus depressa Hayata extract was found to negatively correlate to DPPH scavenging activity, which needs further research to identify other bioactivities of these flavonoids.

The study aimed to determine the effectiveness of metabolites from Lactic Acid Bacteria (LAB) derived Masin (fermented sauce from Sumbawa) as antioxidant, antidiabetic, and antibacterial compounds. The LAB isolates were isolated from various strains of Staphylococcus piscifermentan which consisted of Staphylococcus piscifermentans strain CIP103958 (code: 2), strain BULST54 (code: 17), strain SK03 (code: 11), strain ATCC 51136 (code: 34), strain PCM 2409 (code: 28) and strain PU-87 (code: 5). The Metabolites of LAB were analyzed by the bioprospecting test to indicate antidiabetic, antioxidant and antibacterial activities. The isolate (Code: 5) at 500 ug/ml showed the most effective antioxidant activity up to 71%. The isolate (code: 28), at  300 ug/ml revealed to have the most antidiabetic activity up to  43 %. The isolate (code: 2) showed moderate antibacterial activity with  the inhibition zone of 5.59 mm. The results of the antidiabetic, antioxidant and antibacterial activity showed that the  secondary metabolites produced by LAB from the Masin have broad activities as an  antidiabetic, antioxidant and antibacterial.

ABSTRAKMadu merupakan zat alami yang dihasilkan oleh lebah madu dari nektar bunga dan sekresi tanaman. Madu mengandung mineral, protein, vitamin, asam organik, flavonoid, senyawa fenolik, dan enzim seperti katalase, peroksida, glukosa oksidasi, dan fitokimia lainnya, madu juga memiliki aktivitas antioksidan enzimatik dan non-enzimatik. Komposisi utama madu terdiri dari 80% karbohidrat, 17-20% air, 1-2% mineral dan senyawa organik. Penelitian ini bertujuan untuk identifikasi kandungan antioksidan pada madu hutan di beberapa daerah di Kabupaten Sumbawa. Untuk identifikasi kandungan antioksidan dilakukan analisa aktivitas antioksidan, total fenol, ekstraksi senyawa fenolik, dan identifikasi senyawa fenolik pada madu. Jumlah sampel yang digunakan adalah sampel madu yang diperoleh dari 2 lokasi hutan . Hasil dari penelitian menunjukkan bahwa madu hutan di beberapa daerah tersebut mengandung senyawa fenol (asam galat) sebesar 0,0633 -0,3875 mg/g dan memiliki aktivitas antioksidan antara 3,3365 -30,9680% dengan nilai IC50 60,2 -572,3 mg/mL. Kata kunci: madu hutan, antioksidan, Sumbawa

The Averrhoa Blimbi L. is spread all over in Indonesia as home garden plant. It has not been yet cultivated and developed its utilization. The utilization of this Averrhoa Blimbi L. that can be attempted is that as an instant powder. This fruit contains of chemical elements functioning as natural antioxidant. This study attempts to investigate the variation concentration of Averrhoa Blimbi L. extract on antioxidant activity by using DPPH (1, 1-difenil-2-pikrilhidrazil) method and UV-Vis spectrophotometer. Based on the result of the antioxidant activity test, it is found that different treatment shows different antioxidant activity. At concentration of Averrhoa Blimbi L.: sugar, Y1 (1:1) is -7.8%, Y2 (2:1) is -3.4%, and Y3 (4:1) is 48.4%. This indicates that the more the extract of Averrhoa Blimbi L. is added, the higher antioxidant activity is. The organoleptic test in this study includes colour, aroma, texture, and taste. The most preferred treatment is Y3 (Averrhoa Blimbi L.: sugar: = 4:1). The level of panelist acceptance score on the test parameter is shown as follows: the colour is 2.34 (bright yellow), the aroma is 2.45 (a little bit of sour aroma), the texture is 2.21 (smooth), and the taste is 2.15 (sweet and a bit of sour).