Sensory Evaluation on Viscoelastic Properties of Chicken Meat and its Relation to Stress Relaxation Test

The main purpose of this paper is to investigate the effect of dietary fat level on the viscoelastic properties of raw chicken meat by sensory evaluation test, and to find out the relation between sensory evaluation and stress relaxation test. The chickens used were Cornish×White Rock crossbreds raised in individual wired cages. The number of chickens used was 54 in total, and they were all femals. The were divided into 3 groups, and fed with the experimental diet containing 0%, 5% and 10% of soybean oil, respectively. The feeding periods were 10, 20 and 34 weeks from day-old. Just after slaughter, the breat meat (M.. pectoralis profundus) and the thigh meat (M. iliotibialis) were removed, and were immediately put into polyethylene bags. The samples were kept at-10°C from 0 to 6 months. The size of meat for sensory evaluation were 10mm, 10mm and 5mm respectively. Meat pieces were cooked for 35 sec by electric range (Matsushita denki Co., Ltd.). The panel consisted of 5 members, who were women of 18 to 20 years old. TS (tenderness score), CB (chew counts to beginning point of swallowing) and CE (chew counts to end point of the chewing process) were used as panel scores. Parameters obtained from stress relaxation test were Fmax, τ and S/f0. The following informations were obrained. 1) Except for the chicken meat of 10 weeks old, the panel scores on the thigh meat were generally larger than that on the breast meat, suggesting that the thigh meat was tougher than the breast meat. 2) In the chicken meat of 34 weeks old, TS on the breat meat was larger in chicken fed with diet containing soybeen oil-free diet than in chicken fed with diet containing soybean oi1 (P