不同处理牛肉预煮汁中肌肽含量与抗氧化研究

牛肉预煮汁是目前熟肉制品加工环节的主要副产物,本研究对牛肉预煮汁进行超滤和去离子两种方法处理,采用DPPH法和微生物法测定处理后牛肉预煮汁的抗氧化效果。结果显示:10～100mmol/L的肌肽标准溶液对DPPH自由基有显著的清除能力(P<0.05),肌肽标准溶液浓度与清除率呈高度正相关性r=0.9958;牛肉预煮汁对DPPH自由基具有很强的清除效果,其中,预煮牛肉汁超滤液浓度与清除率呈高度正相关性r=0.9995,而预煮牛肉汁去离子液浓度与清除率呈高度正相关性r=0.9641;从抑菌效应考察牛肉预煮汁的表观抗氧化率得出:牛肉预煮汁的表观抗氧化率随着汁液中肌肽含量的递增呈现极强的正相关性,预煮牛肉汁超滤液与表观抗氧化率相关系数达到0.9977,且预煮牛肉汁超滤液的表观抗氧化率弱于肌肽标准溶液,肌肽标准溶液的抗氧化率又弱于VC,而VC的抗氧化率弱于茶多酚。结论:牛肉预煮汁含有除肌肽以外的更丰富的抗氧化性成分,具有比纯肌肽标准溶液更好的抗氧化效果。

Camosine Content and Antioxidant Activities of Pre-cooked Beef Juice with Different Treatments

The objective of this study was to determine carnosine contents,DPPH free radical scavenging activities and anti-singlet oxygen activities of different treatment products of pre-cooked beef juice as the main byproduct of processing cooked beef products.The results indicated that carnosine standard solution had significant DPPH free radical scavenging ability over the concentration of 10-100 mmol/L（P 0.05） with a highly positive correlation between carnosine concentration and DPPH free radical scavenging rate（r = 0.9958）.Pre-cooked beef juice had a strong scavenging effect against DPPH free radicals.The DPPH free radical scavenging rate of its ultrafiltration fraction with a molecular weight of less than 500 u was highly positively correlated with the concentration（r = 0.9995）.Meanwhile,a highly positive correlation（r = 0.9641） was observed between the DPPH free radical scavenging rate and concentration of deionized pre-cooked beef juice.The apparent antioxidant rate and carnosine concentration in pre-cooked beef juice displayed a very highly positive correlation.The fraction with a molecular weight of less than 500 u exhibited a correlation coefficient of 0.9977,of which the apparent antioxidant rate was smaller than sequentially that of carnosine standard solution,vitamin C and tea polyphenols.These findings demonstrate that pre-cooked beef juice is rich in other antioxidant components besides carnosine and has more powerful antioxidant effect than carnosine standard solution.