Study On Improving Seasoned-Canned Meat Shape By Ultrasound Treatment And Transglutaminase

Effect of different ultrasound treatment on transglutaminase(TGase) activity with sodium caseinate as one kind of substrate is studied by ammonia gas-sensitive electrode method and SDS-PAGE method. Using chicken breast meat as the investigation object, effect of ultrasound treatment on NaCl osmosis is studied by Chinese Standards method, and effect of ultrasound treatment on TGase osmosis is studied by SDS-PAGE. At last, effect of ultrasound treatment and TGase additive on colour and texture characteristic of chicken breast and thigh meat have also been studied.1. Effect of ultrasound frequency, power and treating time on TGase activity was studied by both ammonia gas-sensitive electrode method and SDS-PAGE method. The results showed that, TGase with 20kHz ultrasound 100W-800W treatment for 60min and 40kHz ultrasound 80W-200W treatment for 120min had same activity as control sample, and a-casein,β-casein,κ-casein and whey protein were substrate of TGase. TGase catalyses casein into protein cross-linked with high molecular weight, and SDS-PAGE experiment substantiates ultrasound treatment didn't change with TGase activity.2. Effect of ultrasound treatment on NaCl osmosis is studied by GB/T12457-90 method, as the result, it showed that more NaCl got into the muscle when increasing ultrasound power and treating time. The osmosis was best when treated by 40kHz, 140W ultrasound and 20kHz,500W ultrasound. Furthermore, increasing treating time could get better osmosis when keeping quality of the product and it didn't adding producing cost. Enhancing NaCl additive could also improve its osmosis, but the best concentration of NaCl was no more than 10% because of keeping saltiness of products accepted. The samples with ultrasound treatment reached osmosis balance in less 24 hours than the control, so the ultrasound curing technology can improve curing speed and decrease curing time.3. The extent of myosin heavy chains(MHC) cross-linked by TGase became more when improving the ultrasound power, increasing treating time and TGase additive. The reason why the experiment phenomenon happened may be that ultrasound treatment destroyed the structure of the muscle tissue, and the extent increased when improving the ultrasound power or increasing treating time. Enhancing TGase additive can improve the probability of its omosis. Then more TGase gets into the muscle tissue, the effect of improving chicken texture characteristic is better.4. The changes of chicken breast and thigh meat colour were determinated, after samples were treated by ultrasound, reacted in constant temperature, cooked, and sterilized by high temperature and high pressure. The results showed that, both 20kHz and 40kHz ultrasound made the increase of penetration of TGase when ultrasound power increased, and the cross-linking extent of the chicken protein by TGase also increased, eventually leading to the chicken L value (brightness) decreases, but no significance changed. Myoglobin and nitrosyl myoglobin protein were protected by cross-linked protein, so the value of a(redness) increased, and changed significantly, but chicken b value (yellowness) didn't change regularly. Increasing ultrasound treating time also made it possible to improve the penetration of TGase, and the value of the test samples showed smaller L value, but no significance changed. A value of chicken breast and thigh meat had emerged a highly significant increasing trend. B value of chicken reduced quickly and then changed in a slowly increasing trend, and the reason may be that the cross-linked protein network catalyzed by TGase had yellow smaller degree than the control. The change of chicken color was not significant when increasing the TGase additive, but the weak trend was related to the infiltration of TGase. What's more, the addition of TGase wasn't a significant factor to TGase infiltration capacity. In short, there is no negative impact to chicken colour treated by ultrasound and TGase additive.5. The texture of chicken breast and thigh meat was analysed by Texture Profile Analysis(TPA), after the sample treated by ultrasound and TGase, reacted in constant temperature, cooked and sterilized by high temperature and high pressure. The results showed that the hardness and the chewiness of the chicken breast were greater than that of chicken thigh, because of different muscle fiber structure of them, but their flexibilities were a little different. Treated by 20kHz and 40kHz Ultrasound, the hardness, springiness and chewiness of test samples were greater when the ultrasound power was greater. Greater power ultrasound destroyed the chicken tissue more seriously, so more TGase getting into the muscle improved the texture of the chicken. Treated by ultrasound in 0min-60min, only little TGase penetrated into the muscle, so the total texture characteristic decreased because the ultrasound tenderizing was greater than TGase cross-linking. In 60min-120min, more TGase got into the chicken, so TGase cross-linking became greater to counteract ultrasound tenderizing, even more than it. The total texture of chicken became better. The reason why the trends of breast texture and thigh texture were different can be that there was more connective tissue in thigh meat. Increasing the additive of TGase can improve the chicken texture, but the improvement was not significant. The improvement was significant when the additive of TGase was more than 0.30%, because maybe more TGase additive can make more TGase into the muscle.