Influence of oak chips on chromatic characteristics and phenolics compounds of bog bilberry wine during aging

Spectrophotometry and CIELab methods were used to detect the changes of phenolics levels and chromatic characteristics in aged bog bilberry wines where different densities of oak chips were added.The results indicated that the wines with oak chips showed significant increase in total phenols and anthocyanins compounds during various aging periods.Total flavonoids level was significant higher than control groups in the first and the third month but present no significant difference after 6 months.The proportion of copigmented anthocyanin increased and the ratio of polymeric pigment reduced when added oak chips to bog bilberry wines.Compared with control groups,the L*,b*and H*levels markedly decreased while a*level increased in the wines aged with oak chips.The differences of every index were significant between 2 g / L and 4 g / L oak chips added during 1 month and 3months aging,but showing no significant difference after 6 months aging.The research indicated that oak chips played an important role in influencing phenols and chromatic characteristics of bog bilberry wines,and the addition of oak chips in 4 g / L had more remarkable effect.