全二维气相色谱-串联飞行时间质谱法筛查奶粉中的醛类挥发特征组分

Screening of aldehydes in milk powder using GC×GC-TOF

采用固相微萃取-全二维气相色谱串联飞行时间质谱对奶粉进行了测定,打开包装并放置1年的奶粉共含有47种醛类成分,其中直链醛类共27种,支链醛类共20种;通过主成分分析法筛选出了苯甲醛、(E,E)-2,4-壬二烯醛、2-十一烯醛、壬醛等奶粉氧化变质的特征醛类组分。结果表明,方法有效的测定了奶粉中的醛类成分,为奶粉氧化程度评价提供了量化指标。

Fatty substances in milk powder are susceptible to heat,illumination and oxidation. One type of important products is aldehyde,which can affect the nutrition and sensory quality of milk powder. To evaluation of the oxidation degree of milk powder,aldehydes were chosen as markers and screening by solid-phase micro-extraction and full two-dimensional gas chromatography tandem time of flight mass spectrometry( GC × GC-TOF/MS). 47 aldehydes were detected including 27 linear chains and 20 branched chain structures in open package milk powder after one year storage. The characteristic aldehydes of the oxidation milk powder were selected by principal component analysis,such as benzaldehyde,trans,trans-2,4-nonadienal,2-undecenal,1-nonanal,etc. Results showed that the method can detect aldehydes effectively and provide quantitative indexes for the oxidation evaluation of milk powder.