Polyphenols: The peel and the core Polyphenols are also often called tannins. These compounds are most associated with the bitterness and astringency of hard cider but can also impact color and mouthfeel. There are several types of polyphenols including flavonoids and phenolic acids. Apples, like most fruit, concentrate polyphenols in the peel and the core … Continue reading Polyphenol Concentration in Apples →