Organic acids in Kakadu plum (Terminalia ferdinandiana): The good (ellagic), the bad (oxalic) and the uncertain (ascorbic). (November 2016)

• Record Type: Journal Article
• Authors: Williams, David J.; Edwards, David; Pun, Sharon; Chaliha, Mridusmita; Burren, Brian; Tinggi, Ujang; Sultanbawa, Yasmina
• Is Part Of: Food research international. Volume 89(2016) Part 1
• Page Start: 237
• Page End: 244
• Publication Date: 2016-11
• Subjects: AA ascorbic acid -- Ca calcium -- EA ellagic acid -- ET ellagitannins -- OA oxalic acid -- Ox oxalate; Quantification of organic acids -- Nutraceutical plant -- Kakadu plum fruit and leaves -- Oxalate: Calcium ratio -- Link between oxalic and ascorbic acids -- Identification of individual trees possessing high bioactive tissues; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2016.08.004
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: The phenolic ellagic acid (EA) is receiving increasing attention for its nutritional and pharmacological potential as an antioxidant and antimicrobial agent. The Australian native Kakadu plum ( Terminalia ferdinandiana ) fruit is an abundant source of this phytochemical. The fruit also contains large amounts of vitamin C (mainly as ascorbic acid, AA) and possibly the undesirable oxalic acid (OA). Regular consumption of high oxalate foods poses a variety of health risks in humans including interference with calcium absorption and kidney stone formation. Oxalate is also the end-product of AA metabolism so that consumption of fruit with heightened AA content has the potential to elevate urinary oxalate levels. The aims of this study were to investigate the distribution of EA and the presence of other bioactives in other Kakadu plum tissues. Chemical analysis of Kakadu plum fruit and leaves for EA (free and total), OA (water-soluble and total), calcium (Ca) and AA indicated that EA and AA concentrations were high in the fruit while the leaves had significantly higher EA levels but little or no detectable AA. OA content in fruit and leaves was substantial with the fruit being placed in the high-Oxalate category. These findings suggest that there is potential to elevate oxalate levels in the urine of susceptible people and intake of fruit-derived products should be closely monitored. By measuring tissues collected from specific trees, high EA-producing or low OA-containing individuals were identified. Graphical abstract: Highlights: Measure levels of ellagic, oxalic and ascorbic acids and Ca content in Kakadu plum fruit and leaves Ellagic acid higher in the leaves while fruit exhibited very high ascorbic acid; no ascorbic acid detected in leaves Oxalate high in fruit, placing it in high oxalate food category Oxalate to Ca ratio > 2 for all fruit samples tested Fluctuations in acid contents assessed for whole fruit and leaves from individual trees