Hasil Pencarian  ::  Simpan CSV :: Kembali

"Thesis Supervisors: Dr. Suyanto Pawiroharsono; Prof. Dr. Indrawati GandjarSUMMARYFood deterioration is often due to lipid oxidation, excluding bacterial andenzymatic spoilage. The end-products of lipid oxidation, such as aldehydes,ketones, and alcohols are responsible for unacceptable off-tiavors and off-odors in food. Lipid oxidation can be inhibited by antioxidants.Soybean tempe is the most popular indigenous fermented food inIndonesia. Soybeans are known to contain isotiavones. Four major forms areknown respectively as acetylglycosides, malonylglycosides, glycosides, andaglycones.Tempe were produced from soybean fermentation by Rhizopus oryzaeUICC 524 and Rhizopus microsporus var. chinensis UICC 521. The tempesamples were extracted with methanol and the extraction defatted with hexa»ne. The isoflavone aglycones were isolated using column chromatography,and then anaiyzed using a gradient elution reverse phase of high-pressureliquid chromatography (HPLC). After HPLC analysis, isotiavone aglyconeswere evaporated to dryness and added to soybean oil at the 100, 200, 300,iii ' and 400-ppm concentration in test tubes, then heated at 170°C for 30 minu-tes. The oxidation of soybean oil was measured using the thiobarbituric acid(TBA) test. The result, called thiobarbituric acid reactive substances(TBARS) value, was expressed as pmolll and compared to the syntheticantioxidant, buthylated hidroxytoluene (BHT), at the same concentration.The profile of isoflavone aglycones isolated contains daidzein andgenistein. No factor-2 (6,7,4'-trihidroxyisoflavone) and glycitein were detec-ted. Daidzein resulted from biotransformation of daidzin was dominant inboth tempe samples. The isoflavone biotransformation was much greater byR. microsporus var. chinensis UICC 521 than by R. oryzae UICC 524, exceptfor the 24 hours incubation. After 72 hours of incubation, the total isoflavoneaglycones in tempe using R. microsporus var. chfnensis UICC 521 was721.6 pglg and when using R. oryzae UICC 524, 268.2 p.glg.The oxidized soybean oil without any antioxidants had a TBARS value of327.32 1 20.31 pmol/1. Addition of the antioxidants showed a decreasedTBARS value following increasing concentration for both. For concentrationuntil 300 ppm, the TBARS values of oxidized soybean oil added with isofla-vone aglycones were greater than when added with BHT, respectively55.40 zl: 2.77 pmol!! and 45.20 i 2.63 pmolll. However at concentration of400 ppm, the TBARS values of oxidized soybean oil added with isoftavoneaglycones and added with BHT did not show a significant difference.ix + -51 pp; 6 append; 5 plates; 3 tables.Bilb 35 (1964-1999).iv"

"The negative effect of chemical insecticides has ted to the efforts in tinding altemative strategies for biological pest control. Mycoinsecticide is one ofthe biological pesticides. which is among the most interesting agents of insect control. lt is well known that entomopathogenic fungi can kill insects.There are only few commercial products, which are produced on large scale for several years. Beauveria bassiana is one of the entomopathogenic fungus commonly used as a biocontrol agent for pests of crops. This fungus can be isolated from soil, plant materials or insect cadavers.This thesis consist of two papers, entitled : Isolation, identification and screening of indigenous entomopathogenic fungus B. bassiana from Brebes, Central of Java, and Optimization of mycoinsecticide production of indigenous B. bassiana using rice tlour as a substrate. The aims of these research are to isolate, identify and screen indigenous entomopathogenic fungus B. bassiana from Brebes, Central of Java and to assess the optimization of mycoinsecticide fermentation of indigenous B. bassiana using rice flour as the substrate through solid substrate fermentation (SSF) technique."

"Inoculum for making tempe is usually made from the mould Rhizopus oryzae or Rhizopus oligospons. Large scale use of an inoculum from one source only (LKN-LIPI) might threaten the biodiversity of microorganisms in traditionally made inoculum. The potential use of other Rhizopus moulds as inoculum for tempe production should be examined. Rh. microsporus var. rhizopodifonnis UICC 520 isolated from Hibiscus from Manado and Rh. microsporus var. chinensis UICC 521 isolated from tempe from Aceh were examined for their potentials to produce tempe.Rhizopus has also been known to be able to transform antioxidants such as isoflavone in tempe. The potential of Rhizopus microsporus v. Tiegh. var. chinensis (Saito) UICC 521 to transform glucoside isoflavones in soybean tempe has been evaluated.The results showed that Rh. microsporus var. rhizopodiformis UICC 520 has little potential as a tempe inoculum. Rh. microsporus var. chinensis UICC 521, however, is very potential as an inoculum to produce good tempe and produces abundant spores ((3-10)x106 cell/ml) on rice substrate.Two types of aglycon isoflavone, daidzein and genistein, were detected by TLC separation. The total isoflavone concentration during fermentation period of 24, 48, 72 hours was determined using HPLC. At 24 hours the concentration was 0.142 mg/g tempe, while at 48 and 72 hours the concentration were 0.181 and 0.135 mg/g tempe, respectively. The highest total isoflavone concentration was detected at 48 hours fermentation period. Hence, there was an increase of aglycon isoflavones up to 6000% after transformation of isoflavones in soybean by Rh. microsporus var. chinensis UICC 521 when compared to the initial concentration before transformation."