Gil-Izquierdo A, Gil M I, Ferreres F, Tomás-Barberán F A
Departamento de Ciencia y Tecnología de Alimentos, CEBAS (CSIC), P.O. Box 4195, 30080 Murcia, Spain.
J Agric Food Chem. 2001 Feb;49(2):1035-41. doi: 10.1021/jf0000528.
Hand-squeezed navel orange juice contains 839 mg/L phenolics, including flavanones, flavones, and hydroxycinnamic acid derivatives. The flavanones are the main phenolics in the soluble fraction (648.6 mg/L) and are also present in the cloud fraction (104.8 mg/L). During refrigerated storage of fresh juice (4 degrees C), 50% of the soluble flavanones precipitate and integrate into the cloud fraction. Commercial orange juices contain only 81-200 mg/L soluble flavanones (15-33%) and the content in the cloud is higher (206-644 mg/L) (62-85%), showing that during industrial processing and storage the soluble flavanones precipitate and are included in the cloud. An in vitro simulation of orange juice digestion shows that a serving of fresh orange juice (240 mL) provides 9.7 mg of soluble hesperidin (4'-methoxy-3',5,7-trihydroxyflavanone-7-rutinoside) and 4.7 mg of the C-glycosylflavone vicenin 2 (apigenin, 6,8-di-C-glucoside) for freshly squeezed orange juice, whereas pasteurized commercial juices provide 3.7 mg of soluble hesperidin and a higher amount of vicenin 2 (6.3 mg). This means that although orange juice is a very rich source of flavanones, only a limited quantity is soluble, and this might affect availability for absorption (11-36% of the soluble flavanones, depending on the juice). The flavanones precipitated in the cloud are not available for absorption and are partly transformed to the corresponding chalcones during the pancreatin-bile digestion.
手挤脐橙汁含有839毫克/升的酚类物质，包括黄烷酮、黄酮和羟基肉桂酸衍生物。黄烷酮是可溶部分中的主要酚类物质（648.6毫克/升），也存在于浊度部分（104.8毫克/升）。在鲜榨果汁冷藏储存（4℃）期间，50%的可溶黄烷酮沉淀并融入浊度部分。市售橙汁仅含有81 - 200毫克/升的可溶黄烷酮（15 - 33%），而浊度部分的含量更高（206 - 644毫克/升）（62 - 85%），这表明在工业加工和储存过程中，可溶黄烷酮沉淀并包含在浊度部分中。橙汁消化的体外模拟实验表明，一份鲜榨橙汁（240毫升）可提供9.7毫克的可溶橙皮苷（4'-甲氧基-3',5,7-三羟基黄烷酮-7-芸香糖苷）和4.7毫克的C-糖基黄酮异荭草苷2（芹菜素，6,8-二-C-葡萄糖苷），而巴氏杀菌的市售果汁可提供3.7毫克的可溶橙皮苷和更高含量的异荭草苷2（6.3毫克）。这意味着尽管橙汁是黄烷酮的丰富来源，但只有有限量是可溶的，这可能会影响吸收的可用性（可溶黄烷酮的11 - 36%，取决于果汁）。沉淀在浊度部分的黄烷酮无法被吸收，并且在胰酶-胆汁消化过程中部分转化为相应的查耳酮。
