Abstract
Chicken-bone soup stocks were prepared by normal-pressure cooking (100°C) for 30,60 or 180 min, or by high-pressure cooking(115 or 120°C) for 10 or 30 min. The composition, clarity, viscosity, and sensory evaluation of them were measured. Composition of commercial instant soups was also measured. Total solid extracts, crude protein, collagen were increased as the cooking time and temperature increased, and they were very high in soup stocks cooked at 100°C for 180 min and at 120°C for 30 min. The amounts of 5'-AMP,5'-IMP and glutamic acid were lower in soup stocks cooked at 120°C for 30 min than in those cooked at100°C for 180 min. The concentration of almost all the amino acids in soup stock of 120°C for 30 min was the same level as that in soup stock of 100°C for 180 min. Total solid extacts in commercial instant soups were very high, suggesting high amounts of salt and other minerals. One of the commercial instant soups contained very high amount of 5'-IMP and glutamic acid. The viscosity of soup stocks was correlated positively with the amount of collagen. The sensory evaluation showed that chicken-bone-like flavour was stronger in high-pressure soup stocks (120°C for 30 min) than in normal-pressure soup stocks (100°C for 60 or 180 min), and that overall palatability was not improved by the high-pressure cooking.
