Functional Components in Citrus Beverages

摘要

Citrus beverages are often part of our daily diet. Recent animal, case and cohort control as well as epidemiological studies have shown that certain functional components [carotenoids (lycopene and β-carotene), limonoids, flavonones (naringin and naringin rutinoside), folate, and vitamin C] of citrus prevent chronic diseases such as cancer and cardiovascular diseases. Functional components from three single strength commercial 'Rio Red' grapefruit (Citrus paradisi Macf.) juice products namely cartons (100% pure fresh juice and not from concentrate), cans (100% juice from concentrate), and cocktails (35% juice from concentrate), were analyzed by reverse phase liquid chromatography. The levels of vitamin C significantly decreased when half-gallon grapefruit juice cartons were stored at 4℃ for six weeks, but the levels of limonin 17-β-D glucopyranoside (LG) were not affected during the same period. Total flavonone and lycopene levels were significantly higher at six weeks compared to initial levels. Although a significant loss of vitamin C levels was found when cans were stored at room temperature (24℃) for 12 months, LG levels were markedly increased during the same period. Furthermore, total flavonone and carotenoid levels were changed during storage, but no specific trend was observed. When cocktail in polyethylene toluene (PET) containers was stored at room temperature, the levels of vitamin C were significantly decreased; however, LG and lycopene levels were increased. Our experiments suggest that the functional components in grapefruit juice change during storage, depending on the container used. To remain competitive in international and national markets, optimization of these components may be important for the processing industry.