Fiorino Giuseppina M, Losito Ilario, De Angelis Elisabetta, Logrieco Antonio F, Monaci Linda
Institute of Sciences of Food Production, National Research Council of Italy (ISPA-CNR), Via Amendola 122/O, 70126, Bari, Italy.
Department of Chemistry and SMART Inter-department Research Center, University of Bari "Aldo Moro", Via E. Orabona 4, 70126, Bari, Italy.
J Mass Spectrom. 2018 Sep;53(9):781-791. doi: 10.1002/jms.4260. Epub 2018 Aug 3.
Direct analysis in real time-high resolution mass spectrometry (DART-HRMS) was applied to the detection of lipid species in the lipid extracts of farmed salmon samples collected from a local retailer and analyzed right after the purchase and after storage for 4 and 6 days under refrigerated conditions. The recognition of type and composition of lipids detected in DART-HRMS spectra was performed by using the relevant accurate m/z data (accuracy better than 5 ppm) as input for a search on the LipidMaps database. As a result, several fatty acids (FA), either saturated or mono-/poly-unsaturated, and triacylglycerols (TAG) were recognized in the three types of samples from the corresponding negative and positive ion DART-HRMS spectra, respectively. Following, spectral intensities were exploited to monitor the evolution of selected FA and TAG during the refrigeration of salmon meat. In particular, after 4 days of refrigeration, a statistically significant increase was recorded for FA with side chain compositions 18:2, 18:1, 20:5, and 22:6 despite a significant decrease found for TAG with overall side chain compositions 50:4, 52:5, 52:4, and 52:3 after the same time. These evolutions were consistent with a general model already proposed for the effect of low temperature treatments on seafood, implying the action of endogenous lipases, with consequent increase of the free FA amount and decrease in glycerophospholipids and triglycerides contents. The described results indicate DART-HRMS as a promising MS-based rapid tool for the assessment of fish, or other seafood, freshness.
实时直接分析-高分辨率质谱法（DART-HRMS）被应用于检测从当地零售商处采集的养殖三文鱼样本脂质提取物中的脂质种类，并在购买后以及在冷藏条件下储存4天和6天后立即进行分析。通过使用相关的精确质荷比数据（精度优于5 ppm）作为在LipidMaps数据库中搜索的输入，来识别DART-HRMS光谱中检测到的脂质类型和组成。结果，分别在三种类型样本的相应负离子和正离子DART-HRMS光谱中识别出了几种饱和或单/多不饱和脂肪酸（FA）以及三酰甘油（TAG）。随后，利用光谱强度来监测三文鱼冷藏期间选定FA和TAG的变化。特别是，冷藏4天后，侧链组成为18:2、18:1、20:5和22:6的FA出现了统计学上的显著增加，尽管在相同时间后侧链总组成为50:4、52:5、52:4和52:3的TAG出现了显著减少。这些变化与已经提出的关于低温处理对海鲜影响的一般模型一致，这意味着内源性脂肪酶的作用，从而导致游离FA量增加，甘油磷脂和甘油三酯含量降低。所述结果表明DART-HRMS是一种有前途的基于质谱的快速工具，可用于评估鱼类或其他海鲜的新鲜度。
