洋葱皮乙醇提取物对生鲜猪肉色泽、脂质和蛋白质氧化稳定性的影响

为研究洋葱皮乙醇提取物(ethanol extract of onion skins,EEOS)对生鲜猪肉色泽褐变,脂肪和蛋白质氧化以及微生物侵染程度的影响,并与空白对照组和抗坏血酸(ascorbic acid,VC)处理组进行比较,以猪肉亮度值L^*、红度值a^*,以及高铁肌红蛋白(metmyoglobin,MetMb)含量来判断色泽褐变;以不同时间点样品所含硫代巴比妥酸反应物(thiobarbituric acid reactive substances,TBARS)、蛋白质的疏水性和羰基含量分析EEOS对猪肉脂肪和蛋白质氧化的抑制作用;以挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量表征微生物对肉质的侵染程度。结果表明,EEOS能够减少MetMb含量,增加肉样的a*值;第12天时,与对照组相比,20 g/L EEOS处理组TBARS含量下降53.1%,羰基含量下降29.2%,且均低于VC处理组;此外添加EEOS的各组TVB-N值和蛋白质疏水性均低于空白对照组,且呈现浓度依赖关系(P<0.05)。由此可以说明EEOS作为一种天然的抗氧化剂或防腐剂,具有较好的应用前景。

Effect of ethanol extract from onion skin on color,lipid and protein oxidative stability of fresh pork

The effect of ethanol extract of onion skins(EEOS)on color browning,lipid and protein oxidative as well as infection degree of microorganisms of fresh pork was studied,and was compared with control(without any antioxidant)and ascorbic acid(VC).The objective was to determine the effect of color browning by brightness(L^*),redness(a^*),and the content of methemoglobin(MetMb).The inhibitory effect of EEOS on the oxidation of pork lipid and protein was studied based on thiobarbituric acid reacting substances(TBARS),hydrophobicity and carbonyl content of protein in samples at different time points.Total volatile basic nitrogen(TVB-N)content was used to characterize the infection degree of microorganisms to meat quality.Results showed that EEOS could reduce MetMb content and increase a*value of meat samples.On the 12th day,TBARS and carbonyl content of 2.0%EEOS treatment were decreased by 53.1%and 29.2%respectively than control,which were lower than those in VC treatments.In addition,TVB-N values and protein hydrophobicity of each EEOS treatment were lower than control,and showed a concentration dependent relationship(P<0.05).These results indicated that EEOS has a good research prospect as a natural antioxidant or preservative.