气液色谱法分析发酵豆奶中的低碳有机酸

有机酸来自有益菌的代谢产物，通过测定有机酸的组成来了解菌种类型，从而确认产品的保健价值，因此对有机酸测定很有必要。由于发酵豆奶中蛋白质含量较高，为此用硅藻土沉淀发酵豆奶中的蛋白质。此外，因短链脂肪酸及其酯化物的挥发性和水溶性强，分析较为困难。本文采用苄酯化法则测定结果的精密度很高，回收率也较满意。在对四种不同菌种发酵豆奶测定的同时，还对市场上常见的生态口服液和酸奶作了测定。结果表明本测定方法也是适

DETERMINATION OF ORGANIC ACIDS IN FERMENTED SOYBEAN MILK BY GAS-LIQUID CHROMATOGRAPHY

Measurement of organic acids derived from metabolites of biologically nourishing species of bacteria in fermented soybean milk was studied in this paper. In gas-liquid chromatograpth it is very necessary to pretreat the sample due to its high content in proteins and nonvolatile solubles. Firstly, for the pretreatment the precipitation of proteins in fermented soybean milk with diatomites was carried out. Moreover, as short-chain fatty acids and their esters are highly volatile and water soluble, it is rather difficult for measurement by gas-liquid chromatograpty. Therefore, a method of benzyl esterification was adapted in the experiment. The experimental results showed high precision and good recovery. In addition, organic acids in some tonic oral liquids and yogurts were also measured.