摘要
为筛选具有富硒能力兼具良好发酵性能的乳酸菌,利用其作为发酵剂将无机硒转化为有机硒,开发富硒发酵乳制品,研究以32株分离自传统发酵食品的乳酸菌为对象,培养基中添加15 mg/L亚硒酸钠,通过测定菌液OD值筛选硒耐受性较高的菌株,再通过测定菌上清液中亚硒酸钠残留量,计算富硒率,筛选出富硒菌株;将优选菌株接种至脱脂乳中发酵,通过测定产酸曲线、乙醛含量、双乙酰含量,评价各菌株的发酵性能;考察菌株在含有不同浓度亚硒酸钠乳中发酵后富硒情况和发酵乳感官品质的变化,确定适宜的亚硒酸钠添加量;通过测定无机硒乳、无硒发酵乳和富硒发酵乳的羟自由基、DPPH自由基、超氧阴离子自由基的清除能力,评价富硒发酵乳的抗氧化活性。结果显示,32株菌中有13株菌的硒耐受性良好,有4株菌的富硒率在70.00%以上,其中菌株1610的富硒率最高为81.11±2.07%。4株乳酸菌的产酸情况和特质风味物质含量差异较大,其中菌株3379的产酸缓慢且风味较弱,其余3株发酵性能良好。加硒浓度为150μg/L时,发酵乳富硒率为1610(88.39±10.61%)>815(84.33±10.12%)>3888(70.52±8.46%),发酵乳呈乳白色,具有典型发酵乳香气,无红色和金属味。富硒发酵乳的3种自由基清除能力均显著高于无机硒组和无硒发酵组,说明乳酸菌将无机硒转化成有机硒后可提高发酵乳的抗氧化活性。
Selenium-enriched(Se-enriched)lactic acid bacteria(LAB)can convert inorganic Se into organic one to produce Se-enriched fermented milk.In this research,Se-resistant strains were screened out from 32 LAB isolated from traditional fermented food by adding Na_(2)SeO_(3) with a mass concentration of 15 mg/L to medium and detecting the OD value.Furthermore,Se-enriched strains were screened out by detecting the Na_(2)SeO_(3) residue in culture supernatant and calculating Se conversion rate.The optimum strains were inoculated into skim milk and the fermentation performance was evaluated by acid,acetaldehyde and diacetyl.The appropriate Se concentration of fermentation was determined by Se conversion rate and sensory quality.The antioxidant activity was evaluated by detecting the scavenging effects on free radicals in inorganic Se milk,fermented milk and Se-enriched fermented milk.Results showed that 13 Se-resistant strains were screened out from 32,4 best strains Se conversion rate were 70.00% above,and the maximum rate was 81.11±2.07%.In addition,3379 had a poor fermentation performance with low acid-producing rate and low content acetaldehyde and diacetyl,but the rest of three strains had good fermentation.Different Se conversion rate was found in milk containing 150μg/L Na_(2)SeO_(3) fermented by different strains,1610(88.9±10.61%)>815(84.33±10.12%)>3888(70.52±8.46%).Se-enriched fermented milk had potential antioxidant activity reflecting by significant increasing of scavenging effects on hydroxyl,DPPH and superoxide anion free radicals,and good sensory quality reflecting by milk-white color without red and typical fermented milk aroma without metallic taste.
作者
李理
朱珺
林国栋
陈苏
陈丽娥
陈作国
LI Li;ZHU Jun;LIN Guodong;CHEN Su;CHEN Lie;CHEN Zuoguo(Research Institute,Bioengineering Lab,Hangzhou Wahaha Group Co.Ltd.,Key Laboratory of Food and Biological Engineering,Hangzhou Wahaha Group Co.Ltd.,Hangzhou 310018,China)
出处
《中国乳品工业》
CAS
北大核心
2022年第8期9-14,共6页
China Dairy Industry
基金
浙江省重大科技专项领雁计划-竞争性项目(2022C02017)。
关键词
富硒
乳酸菌
发酵乳
抗氧化
有机硒
Se-enriched
lactic acid bacteria
fermented milk
antioxidant
organic selenium
