CHARACTERISTICS OF GELATIN FROM SWIM BLADDER OF YELLOWFIN TUNA (THUNNUS ALBACORES) AS INFLUENCED BY EXTRACTING TEMPERATURES

Gelatin was extracted from the swim bladder of yellowfin tuna (Thunnus albacores) at different temperatures (60, 70 and 80°C) with the extraction yields of 35.6%, 41.1% and 47.3% (dryweight basis), respectively. The α-chains of gelatin decreased with increasing extraction temperatures.Similar amino acid compositions were noticeable among all gelatins, in which glycine constituted the major amino acid. Imino acids ranged from 169 to 172 residues/1,000 residues. Thegel strength of gelatin extracted at lower temperature was higher than that of gelatins extracted at higher temperatures. Gelling and melting temperatures for swim bladder gelatin were 11.07-15.24 and 20.36-22.33°C, respectively. Higher gelling and melting points were observed for gelatin extracted at lower temperatures. Microstructure of gel of gelatin extracted at 60°C was finerwith smaller voids, compared with others. FTIR spectra of obtained gelatins revealed the significant loss of molecular order of the triple-helix. Thus, extraction temperatures showed the directimpact on characteristics of gelatin from swim bladder

Transfer rate measurement of lysozyme by liquid-liquid extraction using reverse micelles with dense CO2

Lysozyme was extracted from aqueous solution into i-octane using reverse micelles in the presence of pressurized CO2. A squat vessel with two independent stirrers was used to measure the mass transfer of the lysozyme across a planar interface. Mass transfer coefficient, k L of the lysozyme from the aqueous to the organic phase was measured at selected ionic strengths, pH, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) surfactant concentrations, temperatures and pressurized CO2. The mass transfer rate of lysozyme was higher in high temperature (318 K) and pressure (20MPa). pH of 9 in aqueous phase showed highest mass transfer rate of lysozyme. The application of pressurized CO2 markedly increased the mass transfer rate of lysozyme comparing to conventional non-pressurized system.Sun-Mi Jung, Un-Mi Shin, Md. Salim Uddin, Sun-Young Park, Hideki Kishimura, Gordon Wilkinson and Byung-Soo Chu