Effects of processing on the polyphenolic content of Armagh Bramley apple products and pomace

The content of health promoting (poly)phenols, ascorbic acid and antioxidants is currently unknown in products produced from the Armagh Bramley apple. Four industrially processed products (diced apple, puree, canned sliced apple and apple sauce), one artisan product (apple butter) and two newly developed products (apple sauce and apple butter) were compared against raw material, with waste pomace also assessed. (Poly)phenol and ascorbic acid content were quantified by LC-UV-DAD. (Poly)phenol content of apple products ranged from 726 to 1919 mg kg^-1 FW. Significant differences were observed between (poly)phenol content of products, demonstrating that (poly)phenolic profile and content is impacted by processing method. The highest mean (poly)phenol content was observed in industrially produced apple sauce and the lowest in an artisan apple butter product which also had the highest antioxidant capacity. Ascorbic acid was reduced by up to 97% by processing. (Poly)phenolic compounds were present at significant levels worthy of valorisation in waste after processing for all products ranging from 1974 to 5588 mg kg^-1 FW. The data clearly shows that processing affects the (poly)phenol content and profile of Armagh Bramley apple products and consequently optimisation of processing technique has the potential to preserve greater bioactive content.