Liu Xuan, Gao Yanxiang, Xu Honggao, Wang Qi, Yang Bin
College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
J Agric Food Chem. 2008 Aug 13;56(15):6480-7. doi: 10.1021/jf800727q. Epub 2008 Jul 12.
A combined high-pressure carbon dioxide (HP-CO 2) and thermal degradation reaction of betanin and isobetanin in aqueous solution was investigated and can be described by a first-order decay. At 45 degrees C, the degradation rate constant ( k) for each pigment component significantly increased (the half-life ( t 1/2) decreased, p < 0.05) with elevated pressure. Furthermore, HP-CO 2 treatment led to lower k values (higher t 1/2 values) than thermal treatment. However, k and t 1/2 values approached those of thermal treatment when the pressure was >30 MPa combined with temperatures exceeding 55 degrees C. Moreover, betanin was more stable than isobetanin under HP-CO 2. E a values ranged from 94.01 kJ/mol for betanin and 97.16 kJ/mol for isobetanin at atmospheric pressure to 170.83 and 142.69 kJ/mol at 50 MPa, respectively. A higher pressure and temperature as well as longer exposure time resulted in higher values of L*, b*, C*, and h degrees . HP-CO 2 induced more degradation products from betanin and isobetanin than thermal treatment with an identical temperature and exposure time.
研究了水溶液中甜菜红和异甜菜红的高压二氧化碳（HP-CO₂）与热降解联合反应，该反应可用一级衰减来描述。在45℃时，随着压力升高，各色素组分的降解速率常数（k）显著增加（半衰期（t₁/₂）缩短，p < 0.05）。此外，HP-CO₂处理导致的k值低于热处理（t₁/₂值更高）。然而，当压力>30MPa且温度超过55℃时，k和t₁/₂值接近热处理的值。此外，在HP-CO₂条件下，甜菜红比异甜菜红更稳定。常压下甜菜红的活化能（Eₐ）值为94.01kJ/mol，异甜菜红为97.16kJ/mol；在50MPa时，分别为170.83和142.69kJ/mol。更高的压力、温度以及更长的暴露时间导致L*、b*、C*和h°值更高。与相同温度和暴露时间的热处理相比，HP-CO₂诱导甜菜红和异甜菜红产生更多的降解产物。
