The function of dietary phenolic acids in cardiovascular health

[Truncated abstract] Dietary phenolics have been associated with protection against the various forms of cardiovascular disease (CVD). This thesis outlines three independent studies, from analytical to intervention, which increase our knowledge on the role of phenolic compounds in preventative health. Particular attention was paid to phenolics found in fruit, as they are a rich source and widely available and consumed, and hence make a large contribution to dietary phenolics intake. While many fruits are rich in phenolic compounds, it is known that specific cultivars vary greatly in phenolic composition. In this thesis, the composition of major phenolics in 29 pre-varietal selections of Western Australian plums was investigated. This knowledge was essential as the first step in a pathway to develop breeding tools to aid identification of fruit that may have enhanced health-promoting capacities. Total phenolics, selected individual phenolic compounds and total antioxidant capacity (TAC) were quantified. Total phenolic concentration was significantly correlated with TAC. Neo-chlorogenic acid and quercetin glycosides were found to be the predominant phenolics. Composition of these predominant phenolic compounds in plums was not significantly correlated with the TAC. In this study, it is argued that the value of in vitro TAC assays to breeding programs may be limited. Further, increasing the focus on individual bioactive phenolic compound was also argued to be more productive to breeding than TAC assays, as patterns of inheritance of TAC are likely to be very complex. Further understanding on the mechanisms of phenolics in preventative health was sought. There is increasing evidence that specific dietary phenolics can enhance production of nitric oxide (NO) a mediator in vascular health.