猕猴桃浓缩果汁中抗坏血酸在人体的利用

中华猕猴桃是我国的特产野果。鲜果中抗坏血酸含量一般在50～400mg/100g,最高可达2000mg/100g。制成浓缩汁后含量约为350～400mg/100ml。为观察其浓缩果汁中抗坏血酸的利用做了人体实验。受试者为9名男大学生,年龄19～23岁,平均体重56.0kg,身长166.6cm。实验分四期,第一及第三期为抗坏血酸饱和期;第二期为十天的对照期,食基础膳,以晶体抗坏血酸补足至每人每日摄入总量为75mg;第四期为十天的实验期,食基础膳,以猕猴桃汁补充抗坏血酸使每日每人摄入总量亦为75mg。对照期及实验期最后三天收集空腹1小时及24小时尿,最后2天取空腹血浆,皆用靛酚滴定还原型抗坏血酸含量。利用率系以实验期尿中排出率与对照期尿中排出率的比值而求得。算出猕猴桃汁中抗坏血酸利用率为94％。对照期及实验期最后三天24小时尿抗坏血酸排出分别为 20 1±1.63及18.8±1.22mg;空腹1小时尿分别为0.94±0.07及0.75±0.07mg。空腹血浆分别为0.83±0.04及0.81±0.02mg/100ml。分别作t试验,皆无显著性差异。并可看出每日供给75mg抗坏血酸可满足男大学生的需要,与以往报告基本一致。

UTILIZATION OF ASCORCIC ACID IN THE CONCENTRATED FRUIT JUICE OF ACTINIDIA CHINENSIS PLANCH BY HUMAN SUBJECTS

Actinidia chinensis Planch is a wild plant originally growing in China, its fruit is rich in ascorbic acid, about 50-400 mg/100g and up to 2000 mg/ 100g in fresh fruit and 350-400 mg/100ml in the concentrated juice.Nine healthy male college students (19 to 23 years old, the mean weight was 56.0 kg, and the height was 166.6 cm) were the subjects. The experiment was divided into four periods: period 1 and 3 (saturation periods) were intended to bring the ascorbic acid in the blood serum of each subject to a consistent level. The control period (period 2) lasted 10 days. All subjects were given a basal diet with supplement of synthetic ascorbic acid to 75 mg intake per day. The test period (period 4) lasted 10 days too. All subjects received the same basal diet as in period 2 and an equivalent amo- unt of ascorbic acid from Actinidia chinensis Planch concentrated juice. Twenty-four-hour and one hour fasting urine samples were collected during the last 3 days of the control and the test periods. The fasting blood samples were taken during the last 2 days of the same two periods. Reduced ascorbic acid was determined in all samples by the indophenol method. Utilization of ascorbic acid in Actinidia chinensis Planch was calculated as follows:_The daily ascorbic acid excretion in the test period/The daily ascorbic acid excretion in the control period×100%The utilization of ascorbic acid of the juice was 94%. The mean 24 hr and 1 hr urinary excrement of ascorbic acid during the control period (20.1 ± 1.63 mg and 0.94 ±0.07 mg) was not significantly different (P>0.05) from those during the test period (18.8±1.22 mg and 0.75±0.07 mg).The mean level of reduced ascorbic acid in blood plasma during the control and test period were 0.83±0.04 mg/100 ml and 0.81±0.02 mg/100ml respectively. The results also showed that the 75 mg intake of ascorbic acid per day could satisfy the normal male college students requirement. This study agreed with the previous works on the subject.