不同发酵方式对铁皮石斛醋有机酸及风味特征影响的分析

Effect of different fermentation methods on organic acids and flavor characteristics of Dendrobium officinale vinegar

以铁皮石斛浆和大米糖化液为原料制备食醋,利用单菌及混菌进行酒精发酵,并采用固、液态方式进行醋酸发酵,得到液态单菌发酵铁皮石斛醋(DV1)、液态混菌发酵铁皮石斛醋(DV2)以及固态混菌发酵铁皮石斛醋(DV3)3种醋样。通过测定其理化指标,采用高效液相色谱(HPLC)法和气质联用(GC-MS)法分析其有机酸和风味物质,并对样品进行对比。结果表明,样品DV3的不挥发酸、总酚、多糖、乳酸、苹果酸、琥珀酸含量最高(分别为0.66 g/100 mL、1.81 g/100 mL、2.55 g/L),乙酸含量最低(37.14 g/L);且其风味物质总数、特征成分数量均最多,分别为75种和36种;且其协调性和滋味较优。不同的发酵方式对铁皮石斛醋的理化指标、有机酸及风味物质的影响较大,结果表明固态混菌发酵最利于铁皮石斛醋风味物质的呈现。

Vinegar was prepared with Dendrobium officinale pulp and rice saccharification liquid as raw materials. Alcohol fermentation was carried out with pure-culture and mixed culture, and acetic acid fermentation was carried out by solid-and liquid-fermentation. Three kinds of vinegar samples were obtained: D. officinale vinegar(DV1) with liquid-fermentation by pure culture, D. officinale vinegar(DV2) with liquid-fermentation by mixedculture, and D. officinale vinegar(DV3) with solid-fermentation by mixed culture. The samples were compared by determining physical and chemical indexes, analyzing the organic acids and flavor compounds by HPLC and GC-MS. The results showed that the sample DV3 had the highest nonvolatile acid, total phenol, polysaccharide, lactic acid, malic acid and succinic acid content(0.66 g/100 ml, 1.81 g/100 ml and 2.55 g/L, respectively),and the lowest acetic acid content(37.14 g/L). The total number of flavor substances and characteristic components were the largest with 75 and 36,respectively, and the coordination and taste were better. The physical and chemical indicators, organic acids and flavor substances of D. officinale vinegar were significantly affected by different fermentation methods, and the results showed that solid-state fermentation with mixed culture was the most favorable for flavor compounds of D. officinale vinegar.