Yang Shu, Zhou Qingxin, Yang Lu, Xue Yong, Xu Jie, Xue Changhu
College of Food Science and Engineering, Ocean University of China.
J Oleo Sci. 2015;64(3):243-53. doi: 10.5650/jos.ess14219. Epub 2015 Feb 13.
The red color of processed shrimp, one of the most attractive attributes and an important criterion for consumers, is often limited by thermal processing (microwaving, boiling and frying), due to astaxanthin degradation. The effect of thermal processing on astaxanthin in Pacific white shrimp (Litopenaeus vannamei) were investigated. A High-performance liquid chromatographic - atmospheric pressure chemical ionization mass spectrometry (LC-(APCI)-MS/MS) method was used to identify and quantify all-trans- and cis-isomers of astaxanthin, and molecular species of astaxanthin esters in fresh and thermal processed shrimps. Total astaxanthin loss ranged from 7.99% to 52.01% in first 3 min under three thermal processing. All-trans-astaxanthin was most affected, with a reduction from 32.81 to 8.72 μg kg(-1), while 13-cis-astxanthin had a rise (from 2.38 to 4.58 μg kg(-1)). Esterified astaxanthin was shown to hydrolyze and degrade, furthermore astaxanthin diesters had a better thermostability compare to astaxanthin monoesters. Astaxanthin monoesters with eicosapntemacnioc acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6), had a lower thermal stability than those with saturated fatty acids, however, it was the opposite of astaxanthin diesters. The findings suggested that the method of thermal processing should be carefully used in the manufacturing and domestic cooking of shrimps. The results also could be useful in calculating the dietary intake of astaxanthin and in assessing astaxanthin profiles and contents of shrimp containing products.
加工虾的红色是其最具吸引力的特性之一，也是消费者评判的重要标准，但由于虾青素降解，这种红色常常会受到热加工（微波、水煮和油炸）的限制。本研究调查了热加工对南美白对虾（凡纳滨对虾）中虾青素的影响。采用高效液相色谱-大气压化学电离质谱法（LC-(APCI)-MS/MS）来鉴定和定量新鲜及热加工虾中虾青素的全反式和顺式异构体，以及虾青素酯的分子种类。在三种热加工条件下，前3分钟虾青素的总损失率在7.99%至52.01%之间。全反式虾青素受影响最大，含量从32.81微克/千克降至8.72微克/千克，而13-顺式虾青素含量有所上升（从2.38微克/千克升至4.58微克/千克）。酯化虾青素表现出水解和降解现象，此外，虾青素二酯比虾青素单酯具有更好的热稳定性。含有二十碳五烯酸（EPA，C20:5）和二十二碳六烯酸（DHA，C22:6）的虾青素单酯的热稳定性低于含有饱和脂肪酸的虾青素单酯，然而，虾青素二酯的情况则相反。研究结果表明，在虾类的生产加工和家庭烹饪中应谨慎使用热加工方法。这些结果对于计算虾青素的膳食摄入量以及评估含虾产品中虾青素的分布和含量也具有参考价值。
