Judul: Aplikasi Khitosan sebagai Bahan Edible  Coating pada Produk Ikan Beku
Abstrak: Frozen process and storage is one of best method to keep fresheness of food during storage. Fish that processed and stored in frozen is potential for dehydration and microbial growth. Due to its antimicrobial agent, film formable, and good barrier of gas and moisture, chitosan try to be applied to frozen fish. This study consists of two steps, preliminary and main. Preliminary step was done to test pH of chitosan solution, antimicrobial, and water vapor permeability. Main step was done to test moisture content, total plate count, and organoleptic. This step used fish that filleted and coated by chitosan then stored in cold storage (-20 °C) for 15 days. The species of fish used is Sweetlips (Plectorhynchus sp.) with size 100-200 g (± 20 x 10 cm). Experimental design used in this research is Complete Random Factorial Design consisting of two factors. The first factor is the concentration of chitosan consisting of a three level, 1,0; 1,5; and 2.0% (b/v). Second factor is the concentration glycerol consisting of two level, 0,25 and 0,50 ml/g chitosan. The best combination of chitosan-glycerol then applied to the main step. The main step used fillet fish without coating and 0,4 mm thickness plastic (polypropylene/PP) wrapped as a benchmark. The preliminary step resulted chitosan with the concentration of 1,0% (b/v) and glycerol 0,25 ml/g chitosan as the best combination. This combination has pH value of 4,59; index of inhibition of E. coli 0,00; index of inhibition of S. aureus 0,03, and water vapor permeability (WVP) 1,6548 g.m-1.atm-1.day-1. Coating application on the frozen fish was done with the dipping method. The fish dipped for 30 seconds, then drained and kept in cold storage. The test of moisture content shows that in all samples of fish tend to show a decrease in moisture content. The value of moisture content of fish coated by chitosan is still lower then others. However, the value of the moisture content of the samples are still in tolerance of frozen fish (± 80%). For total plate count, the sample of fish coated by chitosan has a total value of microbes that lower than others. If compared with fish without coating, the value become 8-28 percent. If compared with the fish that wrapped with plastic, the value become 16-44 percent. In organoleptic (hedonic) test, by 17 panelists, the assessment indicates that the sample of the coating chitosan average ranged between normal (biasa) and quite like (agak suka). This range describes that the score of the assesment is above the average (score of 3-4).
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Judul: Application Edible Coating Made Of Chitosan And “Lemon Cina” Extract (Citrus Mitis) To Fillet Skipjack Tuna (Katsuwonus Pelamis)
Abstrak: One of the organic compound which is safe to use to extend freshness of fish is chitosan. The characteristics of chitosan are easy degraded biologically, non-toxic, strong cation, well coagulant, and easy to form a membrane or film. Chitosan is widely used as a thickening agent, binder, stabilizer, texture forming, and gel manufacture. In addition, to extend shelf life of foodstuffs by using natural ingredients, one of the safe natural ingredients used to extend freshness of fish is “lemon cina” (Citrus mitis) or commonly known as kasturi orange. “Lemon cina" less popular in Indonesia. “Lemon cina” mostly found in North Sulawesi and well known as “lemon cui” and in the Moluccas called “lemon cina”. Edible coating made of chitosan and “lemon cina” extractas preservative and antimicrobial agent could be an alternative to improve shelf life and quality of skipjack tuna fillets. The main objective of this research was to examine the use of “lemon cina” extract and chitosan as an organic preservative and antibacterial agent in the manufacture of edible coating, while the specific objectives of this research were to: 1) study antibacterial ability of edible coating made of chitosan and “lemon cina” extract for skipjack tuna fillets, 2) study the application of edible coating made of chitosan and “lemon cina” extract on characteristics of skipjack tuna fillets during storage at cold temperatures. The results of phase I research showed that presence of antibacterial ability of chitosan (based on TPC analysis) in edible coating formula which is applied on skipjack tuna fillets decreased by increasing of chitosan concentration. The lowest TPC value of skipjack tuna fillets significantly achieved by addition of 1% (w/v) chitosan. At concentration of 2, 3, and 4% (w/v) TPC value of skipjack tuna fillets increased significantly. Results of phase II research showed that the higher the “lemon cina” extract on edible coating, the better the antibacterial ability was. The lowest TPC value of skipjack tuna fillets significantly achieved by addition of 40% (v/v) “lemon cina” extract. TPC value of skipjack tuna fillets increased significantly at concentration 10, 20, and 30% (v/v) of “lemon cina” extract. Results of phase III research showed that the application of edible coating made from 1% (w/v) chitosan and 30, 35, and 40% (v/v) concentration of “lemon cina” extraction skipjack tuna fillets those were stored at 5 °C, for 1, 7, 14, 21, and 28 days clearly showed that the pH, TPC and TVB values were lower than the controled one (without edible coating). Meanwhile, on the parameters of color, texture, and odor, panelists could hardly distinguish the color, texture, and odor of the controled fillets with the treated ones.
Keyword: edible coating, chitosan, lemon cina, antibacterial, skipjack tuna

Judul: Karakteristik Barisan Eksak Pendek HomR(N, ) dan HomR( ,N)
Abstrak: Module merupakan generaIisasi dari ruang ve}ctor, dimana pada ruang vektor skalar-skalamya berasal dati suatu lapangan (field) sedangkan pada module skaJar-skalamya merupalam unsur-unsur dan suatu ring R dengan unsur satuan. Dari suatu grup komutatif yang unsur-unsumya dipadukan dengan unsur-unsur dart suatu ring R, maka akan mengbastlk.an yang namanya R-module. Himpunan seroua fungsi homomorfisma yang memetakan dati R-module M ke R-module N dinotasikan sebagai HomiM,N), dimana HomiM,N) juga merupakan suatu R-module.
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