一种羊酸奶发酵剂的富硒工艺研究

Study on the fermentation condition of Goat yogurt for selenium-enriched

以菌体中含硒量为指标,确定加硒和富硒培养时间、培养温度、菌种接种比例,采用正交实验对加硒浓度、接种量、培养pH和低聚果糖添加量4个较为重要的富硒因素进行优化。结果表明:单因素实验确定加硒时间为菌体培养开始后24h,富硒培养时间60h,培养温度41℃,长双歧杆菌与嗜酸乳杆菌按2∶1混合培养。以菌体含硒量为考察指标,获得最佳发酵条件为:混合菌接种量3%,硒的质量浓度8μg/g,低聚果糖质量浓度1.00%,pH6.5,此时酸奶发酵剂中硒含量约33.46μg/kg。

The impact of the different fermentation conditions was studied on selenium-enriched of the fermentated goat yogurtionthrough single factor screening and orthogonal experimental. The temperature,culture time of selenium-enriched, incubation temperature and the proportion of inoculation was determined by using selenium content in the bacteria as the index. The four important factors including selenium concentration,inoculum size,culture pH and the added amount of oligofruc to selenium were optimized through orthogonal test, The results showed that the single-factor test to selenium was riched after 24 hours of bacteria cultivation, incubated for 60h at 41℃ with ratio of Bifidobacterium Iongum,Lactobacillus acidophilus 2：1 mixed culture through single-factor test. The orthogonal test was done according to the selenium content as the index. The best fermentation conditions were as follow：mixed inoculum of 3%,selenium concentration of 8μg/g, pH6.5,and 1.00% frueto-oligosaccharides by selenium content in yogurt as the main index. The selenium content of goat yogurtion was 33.46μg/kg.