乳酸菌发酵红茶饮料主要营养成分变化

Changes of main nutrients in black tea beverage fermented by lactic acid bacteria

以红茶浸提液为发酵基质,接种植物乳杆菌种子液进行发酵制备乳酸菌发酵红茶饮料,对其发酵过程中pH值、总酸、蔗糖、茶多酚含量进行分析,采用分光光度法及顶空固相微萃取气质联用法(HS-SPME-GC-MS)测定其游离氨基酸及风味物质,并比较红茶浸提液发酵前后二者的变化。结果表明,乳酸菌发酵红茶饮料pH值由4.97降至3.16,总酸由0.15 g/L升至2.38 g/L,蔗糖含量由0.90 g/L降至0.34 g/L;茶多酚含量由15.1 g/L减少至10.6 g/L,游离氨基酸含量由0.921 g/100 g提升至1.175 g/100 g,发酵前后分别检出88和94种挥发性风味物质。乳酸菌发酵红茶饮料较红茶浸提液营养成分更加丰富,酸甜适宜,风味独特。

Using black tea extract liquid as fermentation matrix,a black tea beverage fermented by lactic acid bacterium was prepared by adding Lactobacillus plantarum seed solution,the pH value,total acid,sucrose,tea polyphenol content were analyzed.The free amino acids and flavor substances were determined by spectrophotometry and headspace solid-phase microextraction(HS-SPME-GC-MS),and the changes of the two black tea extract before and after fermentation were compared.The results showed that the pH of the fermented black tea beverage decreased from 4.97 to 3.16,the total acid increased from 0.15 g/L to 2.38 g/L,the sucrose content decreased from 0.90 g/L to 0.34 g/L,the tea polyphenol content decreased from 15.1 g/L to 10.6 g/L,and the free amino acid content increased from 0.921 g/100 g to 1.175 g/100 g.88 and 94 volatile flavor compounds were detected before and after fermentation,respectively.The black tea beverage fermented by lactic acid bacterium was more nutritious than the black tea extract,with suitable sweet,sour taste and unique flavor.