Effects of Different Colloids on the Stability of Anthocyanins in Blackberry Juice

In this study,the effects of different colloids(xanthan gum,pectin,CMC,sodium alginate and chitosan)on the stability of anthocyanin from blackberry juice during processing and storage were investigated by measuring the pH values,color,anthocyanin contents and rheological properties. The results demonstrated that the degradation rates of blackberry juice anthocyanins were decreased with the addition of xanthan gum,pectin,CMC,sodium alginate and chitosan at a certain concentration(less than 0.075%). Therein the color and stability were obviously enhanced with 0.05% CMC or 0.10% xanthan addition,which was confirmed by the lowest ΔE value and lower degradation rate. The rheology results showed that the viscosities and storage modulus of juices were increased in the presence of CMC or xanthan. Additionally,some sheet and porous structures were observed by SEM,suggesting the co-pigmentations between anthocyanins and colloids,which consequently resulted in the deduced molecular movement and the enhanced stability of anthocyanins. It is noted that CMC or xanthan is one of the best co-pigments for blackberry anthocyanins.