Dipartimento di Scienze Chimiche, Università degli Studi di Cagliari, Cittadella Universitaria di Monserrato, SS 554 Bivio per Sestu, 09042 Cagliari, Italy.
Magn Reson Chem. 2012 Jun;50(6):436-42. doi: 10.1002/mrc.3819. Epub 2012 Apr 23.
(1)H NMR spectroscopy was employed to study the modifications over time of the water-soluble low molecular weight metabolites extracted from samples of salted and dried mullet (Mugil cephalus) roes (mullet bottarga) stored at different conditions. Samples of grated mullet bottarga were stored for 7 months at -20 °C, at 3 °C, and at room temperature in the presence and in the absence of light and then timely extracted and analyzed by NMR. Principal component multivariate data analysis applied to the spectral data indicated that samples stored at -20 °C maintained similar features over time whereas, along PC1, samples stored at room temperature in the presence and in the absence of light showed, over time, marked metabolite modifications. The comparative analysis of the integrated areas of the selected regions of the (1)H NMR spectra indicated that the major compositional changes due to storage conditions were (i) the increase of the derivatives of the breakdown of phosphatidylcholine (choline, phosphorylcholine, and glycerol), (ii) the breakdown of nucleosides, (iii) the decrease of methionine, tryptophan, and tyrosine, and (iv) the cyclization of creatine. These changes were observed at different storage conditions, with more pronounced trends in the samples stored at room temperature. The role of metabolites in food aging is discussed.
采用 1H NMR 光谱法研究了在不同条件下贮藏的盐渍和干燥的鲻鱼（Mugil cephalus）鱼卵（鱼籽酱）水溶性低分子量代谢产物随时间的变化。将磨碎的鱼籽酱样品在-20°C、3°C 和室温下分别在有光和无光的条件下储存 7 个月，然后及时提取并通过 NMR 进行分析。对光谱数据进行的主成分多元数据分析表明，在-20°C 下储存的样品随时间保持相似的特征，而在 PC1 上，在有光和无光的条件下在室温下储存的样品随时间的推移显示出明显的代谢物变化。对（1）H NMR 光谱选定区域积分面积的比较分析表明，由于储存条件引起的主要成分变化为：（i）磷脂酰胆碱（胆碱、磷酸胆碱和甘油）分解产物的增加；（ii）核苷的分解；（iii）蛋氨酸、色氨酸和酪氨酸的减少；（iv）肌酸的环化。这些变化在不同的储存条件下都有观察到，在室温下储存的样品中更为明显。讨论了代谢物在食品老化中的作用。
