Judul: Pengaruh Suhu dan Kemasan (Biodegradable, HDPE perforated) Terhadap Mutu Buah Jeruk Medan
Abstrak: Citrus is a perishable agricultural commodities so that it need decent and correct storage process. The objective of this research is to obtain the best combination of type of packaging between Biodegradable and perforated HDPE and the chosen temperature of storage room that is 6-8 0C, 25-260C dan 28-310C. Parameter that used were weight loss, water content, total sugar, total acid, levels of vitamin C, and organoleptic. Weight loss of citrus that packed by perforated HDPE and combination of 6-80C is the lowest, which is 1,48%. Of lowest decreased level of water content is obtained from perforated HDPE and 6-80C which is 89,95%. perforated HDPE and 6-80C combination is capable to hold the biosynthesis of ascorbic acid which has 102,08 mg/100g vitamin C at the end of research. Biodegradable is able to compete perforated HDPE at acceptance of organoleptic. But overall perforated HDPE is slightly better than biodegradable.
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Judul: Kajian Teknik Pengemasan Buah Pepaya Dan Semangka Terolah Minimal Selama Penyimpanan Dingin
Abstrak: Papaya and Watermelon are one of the famous agriculture commodity. As a agriculture products, they are perishables. This is because papaya and watermelon are still doing metabolitic activity (respiration). The effect of papaya and watermelon respiration is chemical changing so that caused physical changing. The physical changing as a result of chemical changing could be perceived directly as a color, aroma, texture and flavour changing. People generally prefer to consumed them in cold condition. Before they are ready to consume, papaya and watermelon are processed minimally, including fruits cleaning, paring, and cutting into a smaller size so that make them more interesting and easier to consume. They also has a big size so they havenot finished consumed in once time. So, usually people cut them several time during consumption. Minimally processed cause injury in the fruits so that make it shorter in storage life. The way that we can do to prolong the storage life of the minimally processed of papaya and watermelon is a proper packaging and cold storage. The aim of the research is to get characteristic of packaging, physical, chemical, microbiology’s characteristic of fruits, and quality parameter changing and organoleptic assesment for cold storage according to the technique packaging. It also determine the suitable packaging for the fruits during cold storage. Storage were conducted at five treatment that is using polypropylene packaging with two opened circulation holes (B1), polypropylene packaging with one opened circulation hole (B2), polypropylene packaging with two closed circulation holes (B3), plate with cling film plastic cover (B4), plate with no cover (B5) and conducted in the chiller refrigator with 5 - 100C temperature. The parameter which were tested are proximate test (including water content, ash content, protein content, faty content and fiber content) and quality analysis including physical parameter (texture and color), chemical parameter (water content, total acid content, pH, total sugar content, Aw, vitamin C), microbiological test (TPC) and organoleptic test. The parameter were tested during 14 days storage. The result of research showed that thickness, gramature and density of polypropylene packaging is higher and transmission rate (O2, CO2, H2O) is lower than cling film plastic packaging. Characteristic of papaya and watermelon showed that both of them had a relatively high water content (> 80%), watermelon’s texture was lower than papaya’s, neutral’s pH (6.10 for papaya and 5.60 for watermelon), papaya and watermelon’s Aw were 0.82 dan 0.80. They also has a relatively low carbohydrates, protein, and fat. The result also showed that during storage was occurred the increasing microbiological test (TPC). It cause the increasing of water content (except in B5), decreasing of total sugar content, increasing of total acid and decreasing of pH, increasing of color brightness (except in B5), and 0Hue (except in B5 of watermelon) and also increasing of texture content. Organoleptic test showed that fruits that in plate with no cover (B5) had the highest decreasing than the other. Panelists still like the fruits that packed in all of polypropylene packaging (B1, B2, B3) until nine to twelve days, fruits in plate with cling film cover (B4) until eight
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Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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