The influence of simple and condensed phenolics on the clarification of apple juice by honey

The rate at which polyphenolics of six apple cultivars were able to flocculate (coagulate) with honey proteins was compared. Condensed tannins were primarily responsible for the formation of the flocculates. The activity of tannins with honey proteins was high in the cultivars Red Delicious, Rome, and McIntosh (group A), and lower for the cultivars Jonathan, Golden Delicious, and Rhode Island Greening (group B). In order to understand the differences in clarification rates by cultivars, model systems were used to estimate the effect of simple polyphenolic compounds on the formation of insoluble tannin/protein complexes. The addition of chlorogenic acid or gallic acid to the systems containing honey proteins and tannic acid resulted in a significant decrease in the rate of formation of flocculates, whereas the addition of catechol to the above systems did not affect the flocculation time of tannic acid with honey proteins. A hypothesis is put forward to explain these results.