Judul: Validasi metode pengujian kadar imunoglobulin G dalam susu bubuk skim dengan metode enzyme link immunosorbent assay (ELISA)
Abstrak: People take a more proactive approach to maintaining their wellness by looking for natural ways to stay healthy and maintain a balanced immune system such as functional food. Functional foods are foods, and in fact they are foods, that go beyond simple nutrition and have specific targeted actions. Various strategies have been adopted to develop functional foods. The last approach to developing functional foods is based on the addition of ingredients that are very specific and have a very targeted action, that are used to reduce the risk of disease. Milk-based products enriched with immunoglobulins are recently available in the market. The active ingredient, colostrum, is targetted at maintaining health and the natural microbiota. The product is claimed to be lactose-free and fat- free, to have benecifial effects on the immune system and to improve the health of muscles and joints. Immunoassay is development of food analysis which is antibody-based optical were used as to determine IgG because of their simplicity, sensitivity and spesificity. Immunoglobulin G (IgG) in skim milk powder were analyzed by Sandwich Enzyme Link Immunosorbent Assay using bovine IgG ELISA kit. However, before adoption analysis method as a routine method, it should be validated. Standard curves were constructed using IgG standard (stock solution is 125ng/ml), ELISA was linear within 0-125 ng/mL range. Therefore, the samples required a 1/500 dilution to approximately 12.8 ng/mL. ELISA was developed for determination of IgG in bovine milk and colostrum with either goat or rabbit antibovine IgG or protein G used as detecting molecule. Performance parameters validation included liniearity, showed a working range of 5,10 ng to 38,42 ng and correlation coefficient r: 0.99. Overall instrument response repeatability relative standard deviation (RSD) were of 3,87% , 9,67% and 4,86% for IgG over 7 analyses for 3 kind of samples and recovery was 111,24%. The technique was applied to the measurement of IgG content in milk powders, and a precision relative standard deviation values of 20%, acuracy of 85-115% and percent recovery of RSD 15%, and the method is specific.
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Judul: Validasi dan verifikasi metode analisis bakteri asam laktat pada produk susu
Abstrak: Lactic acid bacteria (LAB) is a group of bacteria that capable converting carbohydrates (glucose) into lactic acid and mostly grow at facultatif anaerobic condition. At present, the most widely method used to enumerate LAB in some laboratory in Indonesia is incubation in aerob condition. In order to ensure that the method has a good performance, there is a need of method validation. Validation is the confirmation by examination and provision of objective evidence that particular requirements for specified intended use are fulfilled. The purpose of this study is to validate the quantitative method for enumeration of lactic acid bacteria. Two methods of enumeration of LAB in yoghurt were studied, i.e. ISO 7889-2003(E) as a reference method and SNI 2981-2009 as an alternative method. The principle of this method is to grow the facultative anaerobic bacteria in aerobic and anaerobic condition incubated for 3 days at 37 oC on MRSA media. The anaerobic condition was made using Anaxomat jar whose enrich with 10% CO2. The result obtained by these two method were compared. Therefore several parameters such as precision (RSD), relative accuracy, linearity, limit of detection, and limit of quantification were evaluated. The results showed that RSD of these methods between 0.44% and 3.03%, percent recovery of these methods between 97% and 101%, and limit of detection are 3 cfu/mL. It can be concluded that these two methods have good performance characteristics.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf