Judul: Pengaruh Penambahan Bahan Pengental terhadap Kualitas Dadih Susu Sapi dengan Starter Lactobacillus casei.
Abstrak: Dadih is one of the fermented milk products from West Sumatra, Indonesia, and made by fermenting buffalo milk naturally in the bamboo for 48 hours. Limited of raw materials and inconsistency product make dadih difficult to be developed. Improving of process and adding thickening agent hopefully can increase quality of dadih so it will be able to be accepted by people and become one of functional industrial food product that could be commercialized. This study aims to study the influence of thickening agent for quality of dadih and to decide the correct type and concentration of thickening agent. The design of study used completely randomized design factorial, consisted of two factors; they were the type and concentration thickening agent. There are two types of thickening agent, are gelling agent and non gelling agent. The treatment with Gelling Agent was used seaweed and pectin with concentration 0,10%, 0,15%, and 0,20% while the treatment with non gelling agent was used CMC and Arabic Gum with concentration 0,6%, 0,8%, and 1,0%. Parameter of Research were Physical–chemistry analysis which included moisture content, carbohydrate content, protein content, pH, acidity total, and viscosity; microbiology included total plate count bacteria; and organoleptic included hedonic test, same/different test and ranking test. Based on physical-chemistry analysis and microbiologiy of dadih the addition of Thickening Agent and concentration did not give the different result. While, t-test, which used thickening agent with gelling agent and non-gelling agent did not give the different result. Based on hedonic test, the addition of thickening agent gave different result. Panelist graded that adding pectin 0,1% gave better color while they prefer dadih with pectin 0,1% for the flavor. The most delicious of taste were dadih with pectin 0,15%, while dadih with pectin 0,2% gave the best texture by panelist. In generally, dadih with pectin 0,1% more preferable than the other treatments. Based on chi–square test list, organoleptic testing with the same/different test and ranking test showed the result was not different (P>0,05). In the same and different test, dadih with adding thickening agent with gelling agent and non-gelling agent gave the different result with the real dadih. While ranking test showed that dadih with pectin 0,2% gave the best response from panelist was compared the other treatments. From the result of this study it could be concluded that dadih from cow milk with the addition of the pectin thickening agent 0,2% gave the best result than the other treatments in process for making dadih cow milk.
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Judul: Pembuatan Starter Kering Bakteri Asam Laktat dan Pengaruhnya terhadap Karakteristik Dadih Susu Sapi yang Dihasilkan.
Abstrak: Dadih is a traditional food from West Sumatera resulted from natural fermentation of buffalo milk. This natural fermentation process involves a number of microorganisms, including gram-positive and gram-negative bacteria. The presence of gram negative bacteria that are pathogenic can become an obstacle to get safe and healthy food product to consume and easy in the marketing of products, due to the security aspect is less reliable. The processing through a more controlled fermentation process using lactic acid bacteria starter without involving the bacterial pathogens are expected to improve the quality of the resulting dadih. The provision of culture with the preservation in the dry form will facilitate the handling of starter cultures, so that the fermentation is more controlled and the product quality is more assured. Besides that, the availability of dry starter cultures will facilitate the distribution and transportation of starter cultures because dry starter cultures can be sent for long distances without losing the activity of Lactic acid bacteria and have a long storage. Raw materials used in the manufacture of dadih in West Sumatera derived from buffalo milk. The availability of buffalo milk is very limited, that, the alternative used is cow modified with skim milk and jelly therefore it is expected produce Dadih which has the characteristic similar with dadih from buffalo’s milk. This study aimed to verify the making of dry starter of lactic acid bacteria (the combination Streptococcus thermophilus and Lactobacillus casei also Lactobacillus bulgaricus and Lactobacillus casei) and its effect towards the characteristic of resulting cow’s milk dadih. Various analytical results indicate that the interaction of combinations of lactic acid bacteria starter and concentration of dried starter powder of lactic acid bacteria significantly affect to the pH value and moisture content of dadih. interaction of a combination of lactic acid bacteria starter and dried starter powder concentration of lactic acid bacteria did not influence significantly to the value of titrable acid total, viscosity, ash content, and the total amount of lactic acid bacteria in dadih. Friedman test results showed that the assessment of panelists for color, aroma, taste, texture, and general acceptance of dadih was not significantly different. Based on weighting method for the determination of the best dadih products, showed that dadih fermented by a combination of starter S. thermophilus: L. casei (1 : 2) as much as three grams of powder has the highest weight value. Thus, the recommendation of the best dadih product is dadih product fermented by a combination of starter S. thermophilus : L. casei (1: 2) as much as three grams of dried starter powder. Microbiological test results showed that the lowest total lactic acid bacteria contained in dadih products, that is 8.4 x 109 CFU/ml. Thus, the dadih is eligible as fermented milk for the minimum amount of total lactic acid bacteria ranged 106-109 CFU/ml (Sari, 2007).
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular