延长豆浆保质期工艺条件的优化

Optimization of Technological Condition on Shelf-life of Soybean Milk

豆浆营养物质含量丰富,深受人们的青睐,但极易受到微生物的污染,使其保质期缩短。分别从大豆原料、模拟管道、豆浆产品三方面进行控制,确定了大豆原料、模拟管道、豆浆产品最优的杀菌方式:大豆原料采用传统的100℃水浴巴氏杀菌10 min;模拟管道用有效氯浓度(ACC)为(17±0.5)mg.L-1的酸性电解水清洗;豆浆产品在100℃条件下杀菌5 min,并添加0.15 g.kg-1乳酸链球菌素(Nisin)。在上述条件下,豆浆产品中所有细菌全部被杀死或杀伤,25℃保藏条件下保质期为4 d。同时初步鉴定出大豆原料及豆浆中最难致死细菌(S)为蜡样芽孢杆菌(Bacillus cereus)。

Soybean milk is one of the favourite drinks in China.However,it is vulnerable to microbial pollution extremely for its rich nutrition,which leads to short shelf-life.To solve this problem,this paper considered different combinations of soybean raw materials,simulative pipelines and sterilization methods for finished soybean milk.The results showed the best sterilization way： First of all,soybean raw materials adopted traditional 100℃ water-bath pasteurizing to sterilize for 10 min;Secondly,simulative pipeline was washed by acidic electrolysis of water with the concentration of available chlorine（ACC） at（17±0.5） mg·L^-1;Thirdly,the sterilization temperature,sterilization time and additive amount of Nisin was controlled at 100℃,5 min and 0.15 g·kg-1,respectively.Through above sterilization way,all the bacterias in the soybean milk were killed or damaged,ensuring 4 d shelf-life under the condition of 25℃.Besides,we also preliminary identified the toughest bacteria（S） to kill both in the soybeans and soybean milk was Bacillus cereus strain.