菠萝果酒酵母筛选及发酵性能测试

从不同成熟度的菠萝皮中分离酵母菌,通过一级筛选,得到45株产香和产酒较好的菌株,再通过杜氏管法筛选得到发酵速度较快的12株产香和产酒较优良的优势菌,三级筛选是将这12株菌接种到菠萝汁发酵液中,筛选出一株适合菠萝汁发酵的产酒和产香性能较优的菌株。并对该菌株的温度、pH值、初始糖度、SO2及酒精度耐受性进行了测试。结果表明,35℃以上的温度条件下酵母菌酒精产率下降,30℃产酒率最高;pH5.0酵母菌酒精达到最大;初糖浓度超过25°Be就对酵母菌产生抑制;SO2添加量为60mg/L时,酒精产率提高,产酒率随着添加量继续增加而减小;发酵液中酒精体积分数达到5%时,酵母菌的生长受到抑制,当达到8%,抑制效果加剧,超过11%以后,基本达到酵母菌的耐受极限。

Screening of yeast for pineapple fruit wine production and the fermentation capability testing

A good yeast for production of pineapple fruit wine was screened from the pineapple waste with different grade maturity after three round screening.The strain had a good fermentation capability to pineapple juice,and could produce high alcohol production and typical fruit aroma.The tolerance factors including the temperature,pH,the original sugar content,SO2 and alcohol were investigated.The results show that temperature over 35 ℃,which negatively effect the alcohol production of yeast,suitable temperature is 30 ℃,alcohol production increase to peak under pH 5.0.The fermentation capability of yeast is inhibited when original sugar content grows over 25 °Be.SO2 treatment concentration at 60 mg/L is good for fermentation,which continue increasing will reduce the alcohol capacity of yeast.The limitation of alcohol resistance is 11%.