固相微萃取结合气相色谱-质谱联用法分析冷冻草莓汁异味成分

Identification of Off-Flavor Components in Frozen Strawberry Juice

为了解超高压处理的草莓汁在冷冻贮藏过程中产生的异味物质的主要成分,400MPa压力处理15min的草莓汁分别置于-60、-18、-5℃条件贮藏4周时间,采用不同涂层的固相微萃取纤维头和气质联用法分析、鉴定草莓汁冷冻贮藏后香气成分,找出异味的主要成分。结果表明:草莓汁经冻藏后香气成分发生了变化,产生不悦的异味;通过对比新鲜草莓汁,发现草莓汁在冻藏后产生了硫化氢和异辛醇,该两种物质是草莓汁冻结异味的主要原因。

In order to evaluate the major off-flavor components in frozen strawberry juice after ultra-high pressure （UHP） treatment, strawberry juice was subjected to UHP treatment at 400 MPa for 15 rain, and then stored at -60, - 18 ℃ and -5℃ for 4 weeks, respectively. Solid phase micro-extraction （SPME） with different fiber coatings and gas chromatography- mass spectrometry （GC-MS） were used to analyze and identify the major off-flavor components. The results showed that volatile flavor components of strawberry juice after frozen storage revealed an obvious change and unpleasant off-flavor was observed. Compared with unfrozen strawberry juice, hydrogen sulfide and isooctyl alcohol were detected in frozen strawberry juice as the major off-flavor sources.