Thermal gelation properties of spent hen mince and surimi

Thermal gelation properties of spent hen mince and surimi were investigated. The mince from 98-wk-old spent hens was washed two times with 0.1% NaCl. A portion of unwashed and washed mince was mixed with 4% sugar, 4% sorbitol, and 0.2% Na-tripolyphosphate to produce surimi and was kept frozen at -20 C. The mince and surimi were ground with 3% NaCl and a small amount of water to adjust the final moisture content to 80%. A 6 to 8% potato starch was mixed with some pastes. The pastes were stuffed into sausage casings and heated by one-step and two-step heating. The effects of washing, heating, and addition of ingredients on the color, composition, and functional properties of the mince and gel were compared. Washed, spent hen mince was lighter and less red in color and higher in collagen, gel strength, water-holding ability, and cooking yield than unwashed mince. The best temperature and time schedule for the gelation of spent hen mince was 90 C for 15 min in one-step heating. Heating at 100 C for 5 min after preheating at 60 to 70 C for 30 min resulted a gel with distinctly improved gel strength. Sucrose (4%), sorbitol (4%), and Na-tripolyphosphate (0.2%) improved the gel quality of nonfrozen mince but showed little cryoprotective effect against the degradation of frozen-stored product. A 6% potato starch improved the gel texture, cooking yield, and water-holding ability compared with 8% starch.