Benzie Iris F F, Chung Wai Y, Wang Junkuan, Richelle Myriam, Bucheli Peter
Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong.
Br J Nutr. 2006 Jul;96(1):154-60. doi: 10.1079/bjn20061796.
The carotenoid zeaxanthin is concentrated within the macula. Increased macular zeaxanthin is suggested to lower the risk of age-related macular degeneration. The small red berry, wolfberry (Fructus barbarum L.; Gou Qi Zi and Kei Tze), is one of the richest natural sources of zeaxanthin. However, carotenoid bioavailability is low, and food-based products with enhanced bioavailability are of interest. The present study investigated zeaxanthin bioavailability from three wolfberry formulations. Berries were homogenised in hot (80 degrees C) water, warm (40 degrees C) skimmed milk and hot (80 degrees C) skimmed milk, with freeze drying of each preparation into a powdered form. A zeaxanthin-standardised dose (15 mg) of each was consumed, in randomised order, together with a standardised breakfast by twelve healthy, consenting subjects in a cross-over trial, with a 3-5-week washout period between treatments. Blood samples were taken via a venous cannula immediately before (fasting) and 2, 4, 6, 7, 8 and 10 h post-ingestion. Zeaxanthin concentration in the triacylglycerol-rich lipoprotein fraction of plasma was measured by HPLC. Results showed that triacylglycerol-rich lipoprotein zeaxanthin peaked at 6 h post-ingestion for all formulations. Zeaxanthin bioavailability from the hot milk formulation was significantly higher (P < 0.001) than from the others. Mean area under the curve (n 12) results were 9.73 (sem 2.45), 3.24 (sem 0.72) and 3.14 (sem 1.09) nmol x h/l for the hot milk, warm milk and hot water formulations, respectively. Results showed clearly that homogenisation of wolfberry in hot skimmed milk results in a formulation that has a 3-fold enhanced bioavailability of zeaxanthin compared with both the 'classical' hot water and warm skimmed milk treatment of the berries.
类胡萝卜素玉米黄质集中于黄斑区。黄斑区玉米黄质含量增加被认为可降低年龄相关性黄斑变性的风险。小红果枸杞（宁夏枸杞；枸杞子和茨子）是玉米黄质最丰富的天然来源之一。然而，类胡萝卜素的生物利用度较低，因此具有更高生物利用度的基于食物的产品备受关注。本研究调查了三种枸杞制剂中玉米黄质的生物利用度。将枸杞果实分别在热水（80℃）、温脱脂牛奶（40℃）和热脱脂牛奶（80℃）中匀浆，然后将每种制剂冷冻干燥成粉末状。在一项交叉试验中，12名健康且同意参与的受试者随机依次服用每种含15 mg玉米黄质标准剂量的制剂，并搭配标准化早餐，各治疗之间有3至5周的洗脱期。在摄入前（空腹）以及摄入后2、4、6、7、8和10小时通过静脉插管采集血样。采用高效液相色谱法测定血浆中富含三酰甘油的脂蛋白部分的玉米黄质浓度。结果显示，所有制剂中富含三酰甘油的脂蛋白玉米黄质在摄入后6小时达到峰值。热牛奶制剂中玉米黄质的生物利用度显著高于其他制剂（P < 0.001）。热牛奶、温牛奶和热水制剂的平均曲线下面积（n = 12）结果分别为9.73（标准误2.45）、3.24（标准误0.72）和3.14（标准误1.09）nmol·h/L。结果清楚表明，枸杞在热脱脂牛奶中匀浆制成的制剂，其玉米黄质生物利用度比用“传统”热水和温脱脂牛奶处理枸杞果实的制剂提高了3倍。
