Abstract
The annual processing weight of chickens in Kyushu is about 900,000 t, about 17% of which is occupied by chicken bones. However, chicken bones are rarely used in foodstuffs. In this study, we focused on chicken soup as a method to utilize the chicken bones. We investigated the influence of the cooking method (the heating method) on the taste component of the chicken soup. We compared two heating methods, gas and induction, with the same quantity of heat. The chicken soup was made of 1 kg of chicken bones, 2 L of water, and 3 g of salt, and was heated for 90 min. A fully automatic amino- acid- analysis machine and high performance liquid chromatography were used to analyze the amino acids of the chicken soup. The preference survey of the chicken soup was conducted by 20 years-old women, who used a five-point-grading method and a non-parametric Wilcoxon signed-rank test. The free asparagine components in the chicken soup was higher when gas heating was used than when induction heating was used, but the total amino acid components of the chicken soup was almost same in both. The preference survey demonstrated that the degree of transparency of the chicken soup by gas heating was significantly higher than that by induction heating;the measuring instruments yielded a similar result. We considered that this difference is because of the difference in the convection velocity of the water at 98°C the velocity during gas heating was higher than that during induction heating.
