微波焙烤咸干花生在贮藏过程中的品质与风味变化

Changes on quality and volatile flavor compositions of salty peanut by microwave baking during storage

选取生产上有代表性的鲁花、四粒红、大白沙3个花生品种,采用中试规模的隧道式微波炉进行干燥脱水,制备微波焙烤咸干花生产品,冷却后密封分装保存于室温(20℃)条件下,考察贮藏过程中产品主要理化指标酸价、过氧化值、水分含量和7种典型挥发性风味物质[2,5-二甲基吡嗪、2-乙基-3,5(6)-甲基吡嗪、2-乙基-6-甲基吡嗪、2-戊基呋喃、2,3-二氢苯并呋喃、苯甲醛、苯乙醛]含量的变化,采用Rancimat法推算产品货架期。发现随贮藏时间的延长,酸价、过氧化值增加,风味物质含量降低,其突变拐点均出现在27周左右,与产品货架期一致。进一步数据分析表明,酸价、过氧化值与水分含量呈显著的线性关系(p<0.000 1),其中酸价与水分含量的相关系数(R2值)为0.920 9,过氧化值与水分含量的R2值为0.963 9;典型相关性分析表明,风味成分含量与油脂氧化之间的相关关系显著,其中过氧化值与风味成分含量的关联度最大,R2值为0.993 0。原料不同,贮藏过程中微波焙烤花生品质和风味的变化也表现出一定差异,大白沙花生的酸价、过氧化值优于鲁花、四粒红,良好风味物质的总含量更高、损失速度更低,不良风味物质的含量更低、损失速度更高,与鲁花、四粒红相比,大白沙更适宜于生产微波焙烤咸干花生产品。

Peanut cultivars Luhua,Silihong and Dabaisha were dehydrated by tunnel microwave technology with pilot-scale,seal-packed and stored at 20℃.Changes on quality,such as acid value（AV）,peroxide value（PV） and moisture content,and seven kinds of volatile flavor compositions（2,5-dimethylpyrazine,2-ethyl-3,5（6）-dimethyl-pyrazine,2-ethyl-6-methylpyrazine,2-pentyl-furan,2,3-dihydro-benzofuracoumaran,benzaldehyde and phenylaldehyde） of the peanut product were investigated,followed by shelf life determine by rancimat method.Results showed fast oxidation of peanut oils and fast decrease of the contents of volatile flavor compositions in the products,which appeared at the 27th week during storage.This period was consistent with the shelf life of the products.Both AV（R2 as 0.920 1） and PV（R2 as 0.963 9） were positively correlated with moisture contents during storage.Canonical correlation analysis revealed that the contents of 7 volatile flavor compositions were positively correlated with oxidation degree of peanut oil.During storage period,both AV and PV of cultivar Dabaisha were maintained with higher contents of good flavor and lower off-flavor contents.All results indicated that cultivar Dabaisha was more suitable for producing peanut snack food by microwave baking than Luhua or Silihong.