Abstract:
Factors affecting efficiency of soy protein extraction, comprising pH of extracting solution(7-12),extracting time(8,10,15,20 min.) and soy bean to extracting solution ratio(1:8,1:10,1:12,1:14) were initially studied. It was found that 79%. protein which was the maximum quantity could be extracted at pH11,1:8 ratio of bean to extracting solution and 8 min. extracting time. The resulting protein was texturized by varying total solid content in the protein slurry(10,15,20%),freezing method(plate freezing, dry ice freezing) and method of ice crystal removal(substitute with 95 ethyl alcohol,freeze drying).It was found that protein slurry with 10 total solid,plate freezing until the product temperature at 1 c.m depth reached -37°C and removing of ' ice crystal with 95% ethyl alcohol provided well defined fibrous structure, 18N.shear strength and "slightly like" texture score. Then the texturized protein was heat stabilized in autoclave at various temperatures (105,110,115°C) and times (5,7.5,10 min.).The more cohesive fibrous structure product with 38N.shear strength and 11 moderately like 11 texture score could be produced when autoclaving the texturized protein at 115°C for 7.5 min. Ready-to -eat meat analogue was produced from the heat set texturized protein by varying the flavor type (chicken, pork, beef) at different quantity (5,7.5%) and added fat at 0 or 10%. The sensory evaluation result revealed that the highest acceptable score which belonged to the product with 7.5% pork flavor and 10% fat was not in the "acceptaple" level. Since there was comment on residual of ethyl alcohol flavor, improvement of the textured protein quality was carried out by heating the sample in vacuum oven at 60 or 65°C for 5,6,7 or 8 hrs. Itwas found that the residual alcohol could completely be removed by 7 hr. heating at 60°C, 27 in.Hg. Ready-to-eat meat analogues were produced again from the textured protein, the quality-improved-textured protein and Kaset protein, each using 7.5% pork flavor and 10% fat. Sensory evaluation results revealed that the product was accepted at the same level as that produced from Kaset protein. Another acceptable product produced from the quality-improved protein is ham which was cured in curing solution containing 2% salt, 3% sugar, 7.5% pork flavor and 0.5% sodium tripolyphosphate. After curing, the product was smoked at 60°C for 60 min.