摘要
本实验主要原料为白刺果,其含有丰富的花青素、多酚、黄酮以及较高的含糖量,常被人们称为"沙漠樱桃"。白刺果汁糖分较高、酸度较低,故容易与其他产品结合。本研究利用植物乳杆菌,保加利亚杆菌和嗜热链球菌复配制得的乳酸发酵剂对由干果制成的白刺原汁进行发酵。本研究旨在对其发酵工艺进行优化,以发酵液总糖含量变化率,pH值和感官分数作为主要指标。结果表明,最佳的发酵工艺为:菌种配比为1:2:1(植物乳杆菌:保加利亚杆菌:嗜热链球菌),白刺原汁固液比为1:8,接种量为2%,装液量为75%,在34℃条件下发酵36-48h。此时,发酵白刺果汁的总糖含量变化率达到82.44%,pH为5.0,感官分数高达9.2分,花青素含量为1.22mg/mL,蛋白质含量为5.8mg/100mL。用此发酵工艺制得的白刺果汁,是一款富含营养,色泽饱满,具有独特乳酸香气,酸甜可口的高档发酵饮品。
The mainly raw material of the experiment is nitraria.Nitraria is rich in anthocyanins,polyphenols,flavonoids,as well as carbohydrate,so they are also called "desert cherry".Nitraria fruit beverage has special property with high sugar content and low acidity,then it is easy to integrate with other products.The lactic acid fermentation agent of this experiment was complex formulated by Lactobacillus,Bulgarian bacillus and Streptococcus thermophilus,which wereused to ferment the juice of dried nitraria.The purpose of this experiment was to optimize the fermentation process of the nitraria fruit beverage depending on the rate of the total sugar content,pH and sensory score as the key indicators.The result showed that the best fermentation process as follows:the strain ratio was 1:2:1(Lactobacillus:Bulgarian bacillus:Streptococcus thermophiles),the solid-liquid ratio of nitraria juice was 1:8,the inoculum size was 2.0%,the loaded liquid was 75%,the fermentation temperature was 34℃.and the fermentation time was 36 to 48 h.Under theseconditions,the rate of the total sugar content reached 82.44%,pH was 5.0,the sensory score reached 9.2,the content of anthocyanin was 1.22mg/mLand the concent of protein was 5.8mg/100 mL.This fermented nitraria fruit beverage is rich in nutrients and full of colour and lustre,at the same time,it has the unique lactic acid aroma and suitable sweet and sour tastes,equivalent to a high-grade fermented drinks.
引文