Iwan Yusuf Bambang Lelana

Ketahanan Bakteri Psikotrofik dari Produk Perikanan Segar terhadap Bakteriosin

Fresh fishery products are highly perishable and susceptible to spoilage caused by rapid growth and activity of bacteria. Psychotropic bacteria are the major microorganisms responsible for spoilage when these products stored in ice or under refrigeration. The purposes of this study were to isolate psychrotrophic bacteria from fresh fishery products and to evaluate its resistance to bacteriocins. Fresh fishery products (kembung fish, shrimp, shellfish) samples were obtained from Demangan and Kranggan traditional market. Colony count methods were used to enumerate bacteria, whereas isolation and identification of bacteria was performed by the identification method of Lahallec and Colin (1995). The identification conducted were covering Gram staining and cell morphological examintaion (cell form), motilitym presence or absence of an oxidise, mode of glucose utilization, and capacity for glucose or lactose fermentation, H2S production, and gas production. The resistance assyas by bacteriocin were carried out using agar diffusion method. Seventeen isolates were found abd they were classified as Pseudomonas, Xanthomonas, and Flavobacterium/ Cytophaga. The results show that psychrotropic bacteria resistance to supernatant of lactic acid bacteria and nisin.

PENGARUH NATRIUM METABISULFIT (Na2S2O5) TERHADAP WARNA GELATIN KULIT KAKAP MERAH

This research aimed to determine natrium metabisulfit concentration influence to gelatin colour quality of red large snapper skin. Gelatin production was begun with dry skin rehydration, boiling water submerging then size decreasing and acetate acid solution (CH 3 COOH) submerging with pH 3 for 24 hours, skin washing, then refined the skin using blender, then the skin was extracted using water at 90 o C temperature for three hours. The extracted gelatin was filtered using filter cloth, dakron and zeolite. The natrium metabisulfit (0%; 0.25%; 0.5%; 0.75%; 1%, w/w) was added into the filtrate then the filtrate was dried in an oven with 70 0 C for 36 hours. The gelatin leaves was refined using blender. The result of this research shown that natrium metabisulfit concentration influenced (p 0.05) the water content, viscosity, and gelatin gel power. The increasing of natrium metabisulfit concentration were followed by gelatin colour qualities which were getting brighter, while ash contents and sulfide residues which were collected were increasing above the Indonesia National Standard. Natrium metabisulfit concentration 0,25% gave the best result based on Indonesia National Standard 01-3735-1995 compared with other treatments, with specifications : protein content 86.64%, ash content 3.45%, water content 7.52%, sulfide residue 313.61 ppm, viscosity 9.58 cPs, gel power 274.82 bloom, and light yellow colour (2.5 Y 7/4).

KARAKTERISTIK SURIMI DARI CAMPURAN DAGING MANYUNG DAN CUCUT

Manyung ( Arius spp.) and shark ( Carcharhinus sp.) are the most of low value fishes in Yogya. In order to increase the value, the fishes were processed into surimi. In this research, fishes were mixed in different ratio of manyung and shark, namely 90%:10%, 70%:30%, 50%:50%, 30%:70%, and 10%:90%. The water content, protein content, lipid content, sensory properties and gel strength were determined. The result showed that surimi from manyung and shark in ratio of 90%:10% produced the highest folding test value (AA) and the highest score of sensory properties.

KEMAMPUAN PEMBENTUKAN GEL SURIMI MANYUNG (Arius spp.) PADA BERBAGAI KONDISI PEMANASAN DAN PENCUCIAN

Manyung is one of low value fish in Yogyakarta. In order to increase the value, manyung was processed into surimi. In this research, manyung was processed into surimi with different heating temperatures (40, 45, 50, 55, 60, and 70 o C) and washing time frequency (0, 1, 2, 3, 4, and 5 times) to investigate the gel properties of manyung surimi. Gel strength of manyung surimi increased as washing time treatment increased from 0 to 5 times. Statistical analysis showed that the 4 washing time and 5 washing time have similar gel strength and sensory characteristics. Manyung surimi with 5 washing time and pre-incubation at 60 o C followed by cooking at 90 o C produced the highest gel strength.