The Effectiveness of Polar and Non Polar Fractions of Ageratum Conyzoides L. to Control Peanut Rust Disease and Phytochemical Screenings of Secondary Metabolites

The effectiveness of polar and non-polar fractions of Ageratum conyzoides L. to control peanut rust disease and phytochemical screenings of secondary metabolites. Peanut rust disease caused by Puccinia arachidis is one of the important diseases which causes yield loss more than 50%. An alternative control which is more environmentally friendly can be conducted by applying botanical fungicides extracted from weeds. This study aimed to obtain effective concentrations of polar and non-polar fractions of roots, leaves, and flowers of Ageratum conyzoides as well as to investigate secondary metabolites in each extract. A spore germination test was conducted to determine the effectiveness of each extract. An application of 5% polar fraction of the leaves resulted 98±2% ungerminate spores which was not different with the application of 5% polar fraction of the roots which resulted 95±2% ungerminate spores. The use of a polar solvent extracted more diverse secondary metabolites compared with that of a non-polar solvent. Phytochemical screening tests on the three extracts showed that the leaf polar fraction contained more diverse secondary metabolites as compared with the others. The polar fraction of the leaves contained alkaloids, flavonoids, tannins, saponins, and terpenoids. A further test to confirm the existence as well as to separate these compounds with thin layer chromatography showed that alkaloids, flavonoids, saponins, and terpenoids separated into 7, 9, 6, and 8 spots, respectively. These secondary metabolites may be responsible to inhibit the spore germination of P. arachidis

Mikroanalisis Kandungan Senyawa Fenolik Total Ekstrak Biji Kedelai Dengan Reagen Folin-Ciocalteu

Phenolic compounds in plants function as a chemical defense system to inhibit the growth of pathogens. Folin-Ciocalteu (FC) reagent may be used to estimate the total phenolic compounds using spectrophotometry. Microanalysis of the phenolic compounds using FC reagent has not been widely used. This study aimed to develop a rapid method in estimating total phenolic compounds in soybean grain extract using a 96-wells microplate. An optimum kinetic reaction was achieved after 90 minutes of incubation. Responses of 25–1,000 μg/ml of gallic acid were linear (r = 0.99). Small amount of reagent was needed in the Microplate 2 (MP) technique. This method was more efficient, practical and environmentally friendly. Hundreds of samples could be analysed using the MP 2 in a shorter time, very useful when working with large number of soybean germplasm collection

Isu Global Keamanan Pangan Kacang Tanah II: Protein Ara H sebagai Alergen

Konsumsi kacang tanah (Arachis hypogaea L.) dapat menimbulkan alergi dengan gejala ringan hingga berat, bahkan dapat menimbulkan kematian bagi pasien yang hipersensitif. Peristiwa ini umum terjadi di negara-negara barat, sehingga menjadi salah satu isu global keamanan pangan kacang tanah. Konsumsi kacang tanah dalam jumlah yang sedikit, mulai dari 100 μg mampu memicu terjadinya alergi. Hingga saat ini terdapat 13 protein kacang tanah, yaitu Ara h1 hingga Ara h13 yang sudah diidentifikasi dan dikarakterisasi. Mayoritas sumber alergen tersebut termasuk dalam seed storage protein. Di antara ke-13 protein Ara h tersebut, Ara h1, Ara h2 dan Ara h3 dikategorikan sebagai alergen utama karena dapat dikenali oleh > 50% serum IgE pasien. Ara h1 dan Ara h2 bersifat tahan terhadap perlakuan suhu dan enzim pencernaan. Tulisan ini mengulas secara komprehensif isu alergen yang disebabkan oleh protein Ara h dan beberapa pendekatan yang sudah dilakukan untuk mengurangi terjadinya alergi ditinjau dari aspek penurunan kandungan Ara h. Beberapa pendekatan untuk mengeliminasi Ara h pada kacang tanah antara lain pengolahan, rekayasa genetika, pemuliaan konvensional selektif dan perlakuan menggunakan enzim. Kombinasi dari beberapa perlakuan akan memberikan hasil lebih baik untuk menurunkan kandungan Ara h

Studi Pengaruh Jenis Pelarut Terhadap Hasil Isolasi Dan Kadar Senyawa Fenolik Dalam Biji Kacang Tunggak (Vigna Unguiculata (L.) Walp) Sebagai Antioksidan

Penelitian ini bertujuan untuk mengetahui pengaruh jenis pelarut terhadap kadar fenolik total dari ekstrakbiji kacang tunggak beserta pengujian aktivitasnya sebagai bahan antioksidan. Uji yang digunakan meliputikadar fenolik total termasuk didalamnya kadar flavonoid total. Pengujian aktivitas antioksidan dilakukan denganmetode 2,2-difenil-1-pikrilhidrazil (DPPH). Metode ekstraksi yang digunakan adalah maserasi dengan pelarutetanol, metanol, 70% etanol, 70% metanol, 80% aseton, 50% aseton, dan 0,5% asam asetat dalam 70% aseton(v/v). Hasil penelitian menunjukkan bahwa 80% aseton merupakan pelarut yang dapat mengekstrak senyawafenolik paling besar dan memiliki aktivitas antioksidan terbesar juga. Kadar fenolik total dan flavonoid totalyang dihasilkan mencapai 8.081,4 EAG/g sampel dan 33.308,3 EK/g sampel, sedangkan aktivitas antioksidanyang terukur mencapai 620,9%. Dengan demikian dapat disimpulkan bahwa kepolaran pelarut mempengaruhikadar senyawa fenolik yang terekstrak dan aktivitas antioksidan

Changes of Chemical Composition and Aflatoxin Content of Peanut Products as Affected by Processing Methods

Peanut production in Indonesia is predominantly used for food, thus information on nutritional aspects and aflatoxin contamination in peanuts is essential in terms of food security and safety. As changes may occur during processing, the effects of processing methods on chemical composition and aflatoxin content in selected peanut products were studied. The dried peanut pods collected from a farmer in Ponorogo, East Java were stored for one month, and then the kernels were prepared into fried peanut (kacang goreng), peanut sauce (sambel pecel), peanut press cake (bungkil kacang), fried-pressed peanut (bungkil kacang goreng), fermented peanut press cake (tempe bungkil kacang), and fried peanut tempe (tempe bungkil kacang goreng). The trial was arranged in a randomized complete design with three replicates. ELISA method was applied for aflatoxin B1 analysis. The results showed that peanut kernels contained 26.3% protein (dw) and 50.4% fat (dw) with relatively low aflatoxin B1 content (9.1 ppb) due to low moisture level (5.6%), no Aspergillus flavus infection and high sound/intact kernels (73.1%). Peanuts processed into tempe bungkil kacang showed the highest increase in protein content, followed by tempe bungkil kacang goreng, bungkil kacang, and bungkil kacang goreng, while fat contents decreased in all products. Processing into kacang goreng and bungkil kacang goreng decreased aflatoxin B1 by 26.4% and 41.8%, respectively, while no significant differences were noted in sambal pecel and bungkil kacang. Aflatoxin B1 increased two-fold during the preparation of tempe bungkil kacang, however it significantly decreased by 38.9% after deep-fried. Excluding peanut tempe, all peanut products contained aflatoxin B1 below the permitted level (15 ppb), therefore they are safe for consumption