Bioactive anthocyanins in 'Queen Garnet' plum - maturity and bioavailability

There is sustained increase in consumer interest in the potential health benefits of dietary derived plant polyphenols and special focus on highly coloured compounds, such as anthocyanins. A new cultivar of Japanese plum Prunus salicina Lindl., named LSQUOQueen GarnetRSQUO, was developed as a high anthocyanin plum in a Queensland (Australia) Government breeding program. LSQUOQueen GarnetRSQUO plum fruit has an outstanding anthocyanin content (up to 280 mg 100 g^-1 fresh weight) which compares well with red-black berry fruit, which are some of the richest dietary sources of anthocyanins. Research was undertaken on the horticultural production conditions to optimize the yield of anthocyanins in LSQUOQueen GarnetRSQUO plum. The impact of increasing maturity on anthocyanin content in LSQUOQueen GarnetRSQUO plum fruit was determined as a tradeoff with potential losses from damage due to adverse weather events, rots and fruit drop. A second line of research developed understanding of the potential health benefits of LSQUOQueen GarnetRSQUO plum in order to influence consumer perceptions and product values. Detailed information about the “matrix release” (bioaccessibility), bioavailability and particularly in vivo metabolism has been obtained to understand the mechanisms of action of these plant pigments as well as their potential role in disease prevention. Bioaccessibility of plant pigments from the fruit matrix was determined using in vitro digestion models. The effects of LSQUOQueen GarnetRSQUO plum juice on biomarkers for oxidative stress and the in vivo metabolism of the main polyphenols was determined in a pilot study with healthy human subjects.