白桃风味近水饮料贮存过程中的风味稳定性研究

Flavor stability of white peach-flavored near-water drinks during storage

采用感官分析与仪器分析相结合的方式,研究了3种市售白桃风味近水饮料保温贮存14 d内的风味稳定性。结果表明,贮存14 d后,3种饮料的白桃风味都有不同程度的劣变。利用固相萃取结合气相色谱质谱联用对挥发性物质定性定量分析,结果表明,3种市售饮料中芳樟醇的含量在贮存过程中随时间延长显著降低,而α-松油醇含量在贮存过程中呈上升趋势。结合感官分析结果,推断芳樟醇和α-松油醇含量的变化是导致风味劣变的主要原因。参照市售饮料样品,建立了白桃风味饮料模型,研究了pH、温度以及维生素C对模型中芳樟醇和α-松油醇变化的影响。结果表明,温度升高和pH值降低都会促进芳樟醇向α-松油醇转变,而维生素C对这一转变影响不明显。且饮料体系pH>4.00时,芳樟醇的降解趋缓。因此,从风味稳定性角度考虑,建议芳樟醇香气贡献较大的风味(如白桃)饮料体系的pH值应控制在4.00以上。

In this study,sensory analysis and instrumental analysis were used to study the flavor stability of three commercial white peach-flavor near-water drinks within 14 days at room temperature and 55℃storage.The sensory analysis showed that the flavor of all samples became weaker after 14 days of storage,especially the weakening of the green note.The volatile compounds of the samples were qualitatively and quantitatively analyzed by solid phase extraction(SPE)combined with GC and GC-MS.As a result,the content of linalool decreased significantly with the extension of storage time,while the content ofα-terpineol increased continuously during storage.This quantitative analysis result was consistent with the sensory analysis result.The content changes of linalool andα-terpineol were the main reasons for the weakening flavor of white peach-flavored near-water drinks and were finally unacceptable.After that,the beverage model of white peach-flavor was established to study the effects of temperature,pH and the addition of vitamin C on the contents of linalool andα-terpineol in white peach-flavored beverages.The experimental results showed that the increase in temperature and the decrease of pH value could promote the conversion of linalool toα-terpineol,but the effect of vitamin C on the conversion was not obvious.In the range of pH 3.00-5.00,the degradation of linalool was more severe in the beverage model with lower pH.In the beverage model with pH 4.00,the content of linalool could still retain more than half of the initial value when stored at 55℃for 14 days.In view of this,for the sake of flavor stability,the flavor(such as white peach)beverage with key aroma compounds of linalool,the pH of the system should be controlled above 4.00.