Effects of ultra-high pressure thawing on San Huang chicken quality by different frozen mothods

The methodology and technique used for freezing and thawing play a very important role in the preservation of the quality of frozen San Huang chicken. Studies were conducted on the influence of San Huang chicken at different freezing manners (refrigerator freezing, air freezing, immersion freezing) and thawing patterns (traditonal thawing, high pressure thawing) in this paper. The indexes including drip loss, color, texture, protein denaturation. The variables to freeze San Huang chicken sample were pressure (100, 150, 200 MPa). The temperature of pressure medium was controlled at 20℃. The results showed that high pressure thawing pattern could shorten the thawing time, but result in more drip loss than traditional thaw and had a significant differences (P＜0.05). Contrary to expectation, the immersion freezing process produced much higher drip loss than other freezing manners. Minimum drip loss was observed at 150 MPa rather than at 100 or at 200 MPa. L*, b*, ΔE had an apparent increase after high pressure process rather than traditional thawing pattern and had a significant difference (P＜0.05), and significant differences (P＜0.05) in L*, b*, ΔE values were found between the different pressures,with the increase of pressure, L*, b*, ΔE values increased. Hardness, springiness and chewiness increased after high pressure process rather than traditional thawing pattern. Salt-soluble protein content and actomyosin ATPase activities had a noticeable decrease during the high pressure thawing process and with significant difference (P＜0.05). High pressure above 100 MPa, 150 MPa caused noticeable myosin heads, actin denaturation, respectively, during the high pressure thawing pattern,the denaturation degree of sarcoplasmic protein was much smaller than that of myosin and actin. DHpeakⅠ+Ⅱ+Ⅲ values had a noticeable decrease and with significant difference (P＜0.05) during the high pressure thawing process. High pressure thawing pattern could shorten the thawing time, but the indexes of frozen San Huang chicken still has a large difference with fresh. The conclusion would be very obvious that the method of high pressure thawing in San Huang chicken isn’t suitable.