Investigating the potential synergistic interactions between whole fruits and vegetables

Abstract

Synergism is defined as a combination of two or more substances, to produce a collective effect greater than each agent separately(1). It has been reported that combinations of different phenolic compounds, in fruit smoothies, can result in synergistic antioxidant effects(2). The objective of the present study is to determine the effect of potential synergistic interactions between fruits and vegetables (FV) on their antioxidant and anti-cariogenic activities. Whole FV including blueberry, red grape, strawberry, red pepper, sweet potato (with and without skin), carrot and garlic were analysed both individually and combined. Antioxidant activity was assessed using the DPPH radical scavenging(3), total phenolic content (TPC)(4) and ferric reducing antioxidant power (FRAP)(5) assays. Anti-cariogenic activity was determined using a standard agar well diffusion method of measuring growth inhibition of the pathogen Streptococcus mutans(6). Red grape and carrot individually were found to have lowest radical scavenging activity (68 +/- 1.81% and 33 +/- 5.79%, respectively), but when combined, the antioxidant potential significantly (p