二十二碳六烯酸强化蛋黄粉的制备及其贮藏稳定性

Preparation and storage stability of docosahexaenoic acid enriched egg yolk powder

以二十二碳六烯酸(DHA)营养强化鸡蛋为原料制备DHA强化蛋黄粉,通过测定pH值、色差值、DHA含量和过氧化值等指标,探讨烘箱加速氧化25 d,及不同温度(4、25、37℃)、光照(照光/避光)和氧气(有氧/无氧)条件下DHA强化蛋黄粉的稳定性。结果表明:冷冻干燥相较于喷雾干燥能更好地保留DHA,制得的DHA强化蛋黄粉中DHA含量为17.1 g·kg^-1。高温氧化使DHA强化蛋黄粉的pH值降低,红度值增加,亮度值下降。37℃贮藏7周时,DHA强化蛋黄粉中DHA的保存率为93.1%。25℃贮藏60 d时,无氧避光条件下DHA强化蛋黄粉中DHA的保存率为95.2%,有氧避光条件下为93.6%;无氧照光条件下DHA强化蛋黄粉中DHA的保存率为94.2%,有氧照光条件下为91.7%,且有氧照光组的过氧化值为有氧避光条件下的3.7倍。综上,温度对DHA强化蛋黄粉中DHA保存率的影响具有主导作用,氧气和光照对DHA强化蛋黄粉的氧化变质具有促进作用。DHA强化蛋黄粉应优先考虑低温、避光、密封存放。

In the present study,docosahexaenoic acid(DHA)enriched egg yolk powder was made from DHA enriched eggs.In order to investigate the effects of accelerated oxidation oven test for 25 d and different storage conditions including temperature(4,25,37℃),light(light/dark)and oxygen(unsealed/sealed))on the storage stability of DHA enriched egg yolk powder,the indicators of pH value,color difference,DHA content and peroxide value were measured.It was shown that freeze-drying process could maintain DHA in the DHA enriched egg yolk powder with a content of 17.1 g·kg^-1.High temperature oxidation reduced the pH and brightness value of DHA enriched egg yolk powder,and increased the redness value.The preservation rate of DHA was 93.1%after storage at 37℃for 7 weeks in the DHA enriched egg yolk powder.When stored at 25℃for 60 d,the DHA preservation rate in the DHA enriched egg yolk powder was 95.2%,93.6%,94.2%,91.7%,in sealed and dark conditions,unsealed and dark condition,sealed and light condition,and unsealed and light condition,respectively.The peroxidation value of the DHA enriched egg yolk powder was 3.7 times under unsealed and light condition as that under unsealed and dark condition.In conclusion,temperature had a leading effect on the preservation rate of DHA in the DHA enriched egg yolk powder,while oxygen and light could promote the oxidative process.The storage of DHA enriched egg yolk powder should give priority to low temperature,and sealed and dark condition.