Chen Yong, Ho Chi-Tang
Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901-8520, USA.
J Agric Food Chem. 2002 Apr 10;50(8):2372-6. doi: 10.1021/jf011244l.
Carnosine occurs naturally in meat and meat products in significant quantity, and it possesses strong antioxidant activity that inhibits lipid oxidation and enhances shelf life. In this study, the effects of carnosine on thermal flavor generation were investigated using the model system of cysteine and ribose, which was heated to the roasting temperature of 180 degrees C for 2 h at pH 5 and pH 8.5. The results indicated that carnosine affected volatile formation in a complex manner. Volatiles identified from the liquid phase of the reaction systems of ribose and cysteine showed that the sulfur-containing compounds such as thiophenes, thiazoles, and polysulfides were the most abundant compounds. The addition of carnosine into the reaction mixtures in general caused a reduction in contents of thiophenes and some important meaty flavor compounds such as 2-methyl-3-furanthiol, 2-furfurylthiol, and their associated dimers. On the other hand, it facilitated the generation of several important nitrogen-containing volatiles such as pyrazine, methylpyrazine, 2,6-dimethylpyrazine, and other alkyl pyrazines and thiazoles, which are known to elicit roasty and nutty flavor notes. The results suggested that carnosine acts as a nitrogenous source to facilitate the formation of nitrogen-containing compounds, possibly by degradation to form ammonia.
肌肽天然大量存在于肉类及肉制品中，具有很强的抗氧化活性，可抑制脂质氧化并延长保质期。在本研究中，利用半胱氨酸和核糖的模型体系，研究了肌肽对热风味生成的影响，该模型体系在pH 5和pH 8.5条件下加热至180℃的烘焙温度2小时。结果表明，肌肽以复杂的方式影响挥发性物质的形成。从核糖和半胱氨酸反应体系的液相中鉴定出的挥发性物质表明，含硫化合物如噻吩、噻唑和多硫化物是最丰富的化合物。向反应混合物中添加肌肽通常会导致噻吩和一些重要的肉香味化合物如2-甲基-3-呋喃硫醇、2-糠硫醇及其相关二聚体的含量降低。另一方面，它促进了几种重要的含氮挥发性物质的生成，如吡嗪、甲基吡嗪、2,6-二甲基吡嗪以及其他烷基吡嗪和噻唑，这些物质已知会产生烘焙和坚果风味。结果表明，肌肽作为一种氮源，可能通过降解形成氨来促进含氮化合物的形成。
