Pengaruh Jenis Umbi Gadung (Dioscorea hispidaDennst.) Terhadap Kadar Bioetanol pada Proses Fermentasi Menggunakan Ragi Roti

The objective of this research is to reveal the influence of the type of gadung to the produced ethanol content, the yeast concentration which is suitable to get the maximum ethanol and to know the interaction between the type of gadung and the yeast concentration on the ethanol content produced. The research using Randomized Complete Design with factorial pattern consisted of 2 factors: the gadung bulb type (U), as the first factor consisting of white gadung tuber (U1) and yellow bulb tuber (U2) second factor yeast concentration consisting of 2 , 5% (R1), 3% (R2), 3.5% (R3). Fermentation duration is done for 3 days. Each treatment is repeated 3 times. The results showed that the proximate analysis on two types of gadung is highest in white gadung. The average width of the highest gadung leaves on white gadung . Test brix on the highest gadung tubers on white gadung. On observation of the highest yield of ethanol occurs on the type of white gadung and 2.5% yeast concentration. The best type of mass observation occurred in yellow gadung tuber type and 2.5% yeast concentration. Observation of initial pH of ethanol was highest in white gadung and yeast concentration 2.5%. Observation of pH after distillation is highest on white gadung and at yeast concentration 2.5%. The highest concentration of ethanol content on yellow gadung and at yeast consentation 2.5%. The observation of the highest ash content on yellow gadung and at yeast concentration 3.5%.

AKTIVITAS ANTIOKSIDAN EKSTRAK UMBI SUWEG (Amorphophallus paeoniifolius) DARI BERBAGAI TINGKAT POLARITAS PELARUT

ABSTRACT Has done research about antioxidant activity of suweg tuber (Amorphophallus campamulatus) based on the level of polar solvent. This research begins with in phased maceration extraction using n-hexane, ethyl acetate dan ethanol. Next step was antioxidant activity test with tyocyanate to n-hexane extract and DPPH methods to ethanol extract, ethyl acetate and vitamin C. The result showed antioxidant activity in n-hexane extract i.e. 14,96 %, end 77,13 % BHT while in ethyl acetate, ethanol and vitamin C reached IC50 value are 458,102 ppm, 223,268 ppm dan 26,76 ppm. Keywords: Suweg tuber, type of solvent, maceration, antioxidant

Using Polymerase Chain Reaction-based DNA Amplification to Fingerprint North American Potato Cultivars

DNA from 46 North American potato (Solanum tuberosum L.) cultivars was examined using the polymerase chain reaction (PCR) with 16 arbitrary primers of 10 nucleotide length (10 mers) to determine the efficiency of randomly amplified polymorphic DNA (RAPD) in delineating cultivars, both sexually derived and clonal variants. The 16 primers yielded 43 useful polymorphisms that were evaluated according to the presence or absence of fragments of equal size. All cultivars were discriminated with as few as 10 primers. The russet sport of Burbank was distinguished from a white-skinned clone by one band. More primers (29) were examined to identify a band polymorphism among six Russet Burbank clonal variants. When the cultivars were grouped by tuber type (excluding the russet clonal variants), three to four primers discriminated these commonly grown cultivars. Determination of cultivar integrity was accomplished with PCR amplification, regardless of tissue source (leaf vs. tuber) for DNA extraction. Cluster analysis based on RAPD markers was performed to examine pedigree relationships of the cultivars. Genetic relationships correlated with some pedigrees; however, many exceptions were noted.

SELECTION OF POTATO GENOTYPES AT SIX WIDELY SEPARATED LOCATIONS IN NORTHWESTERN CANADA

Norgold Russet and six potato (Solanum tuberosum L.) seedlings were grown and evaluated at six widely separated locations in Northwestern Canada for 3 yr. The total number of tubers decreased with increasing latitude but not their marketable number, nor their total and marketable weight. Similarly, tuber type, specific gravity, boiled quality, or general evaluation did not vary with latitude. The personal bias of observers in rating tuber type and general evaluation was largely eliminated by providing detailed instructions to the six observers, by not including disease in general ratings, and by rating on the marketable tubers. There was close agreement in the performance and evaluation of genotypes between Prince George, Beaverlodge, Anzac, Mile 1019 and Fort Simpson but not between Fort Vermilion and any of the above locations. It was concluded that potato genotype evaluation was needed at two locations in northwestern Canada, one at Fort Vermilion and another at any of the other locations, and that potato research at the other locations should be directed towards improving cultural practices.