Grapefruit juice, acid concentrations

Lilja JJ, Kivisto KT, Neuvonen PJ. Grapefruit juice-simvastatin interaction effect on serum concentrations of simvastatin, simvastatin acid, and HMG-CoA reductase inhibitors. Clin Pharmacol Ther 1998 64(5) 477-483. 

In a randomized, two-phase, controlled, crossover study in 10 healthy volunteers one glass of grapefruit juice, taken daily for 3 days considerably increased the plasma concentrations of simvastatin and simvastatin acid (46). 

Co-admuiistration of erythromycin, phenytoin, or valproic acid increases the rate of metabolism of carbamazepine, reducing the blood concentration. Itraconazole and grapefruit juice interfere with CyP 3A4, increasing carbamazepine levels. 

Grapefruit juice-simvastatin interaction effect on serum concentrations of simvastatin, simvastatin acid,... 

Figure 4. Ascorbic acid oxidation in grapefruit juice as affected by oxygen concentration.

Figure 5. Correlation between oxygen concentration and ascorbic acid oxidation in grapefruit juice during storage at 23 2°C.

Fatty acids and amino acids are precursors of a great number of volatile aldehydes, while carbohydrate degradation is the source of ethanal only. Due to its aroma activity at higher concentrations ethanal is of great importance for the fresh note, e. g., in orange and grapefruit juice. 

Ingredients Carbonated water. Concentrated fruit juices (pineapple, grapefruit) (5% when reconstituted). Citric acid. Acidity regulator (sodium citrate). Artificial sweeteners (aspartame, saccharin). Flavourings. Preservative (sodium benzoate). Antioxidants (ascorbic acid, ascorbyl palmitate). Colour (lutein)... 

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