基于电子鼻、气-质联用技术和感官评价方法优化海带发酵脱腥工艺

Optimization of fermentation deodorization of Laminaria japonica based on electronic nose,GC-MS and sensory evaluation

基于酵母发酵法优化了海带脱腥的工艺。结果表明,经不同发酵条件处理后,海带样品整体气味轮廓均无重叠,区分效果良好。将各组样品数据点与原料海带数据点质心间的平均距离进行排序,存在"酵母质量浓度>发酵时间>发酵温度"的趋势。从原料海带中共检出42种挥发物,进一步筛选得到己醛等10种气味活性物质。经不同工艺脱腥后,海带中挥发物种类、总浓度值和气味活性值(odor activity value,OAV)总和均发生了显著下降,除2-辛烯醛和壬醛外的8种气味活性物质其OAV消降值和消降率均较高。在优化条件下(酵母质量浓度1.5 g/L、发酵温度28℃、发酵时间120 min),脱腥后海带样品中挥发物数量由42种降低至24种,总质量分数由287.65 ng/g降低至138.88 ng/g,OAV总和由91.76降低至52.68,感官评分达到最大值(70.5),脱腥效果最佳。由相关性分析可知,感官评分与挥发物总浓度以及OAV总和变化规律间具有较强的一致性,两者相关系数绝对值均达0.8以上,且感官评分与后者的相关性高于前者。研究成果可为相关企业研发海带的高效脱腥工艺提供理论参考。

The deodorization process of kelp(Laminaria japonica)was optimized based on yeast fermentation.The results showed that there was no overlap in the overall odor profile of kelp samples after treatment under different fermentation conditions,and the distinguishing effect was good.By sorting the average distances between the centroid of sample kelp data point and raw material kelp data point in different groups,a trend of“yeast concentration>fermentation time>fermentation temperature”was observed.A total of 42 kinds of volatiles were detected from the raw kelp,and ten kinds of odor active substances such as hexyl aldehyde were further selected.After deodorization treatments under different conditions,the type,total concentration and total odor activity value(OAV)of volatiles in kelp decreased significantly.The OAV degradation value and degradation rate of eight odor active substances were high,except for 2-octene aldehyde and nonanal.Under optimized conditions(yeast concentration of 1.5 g/L,28℃and fermentation time of 120 min),the number of volatiles in kelp samples decreased from 42 to 24,the total concentration decreased from 287.65 to 138.88 ng/g,the total OAV decreased from 91.76 to 52.68,and the sensory score reached the maximum(70.5),realizing the best deodorization effect.Through correlation analysis,strong consistencies were obtained for the sensory score with both the total concentration and total OAV of volatiles.The absolute value of the correlation coefficient was above 0.8,and the correlation between the sensory score and total OAV was higher than that between the sensory score and total concentration.The results provide a theoretical reference for the research and development of kelp deodorization process.