OPTIMIZATION OF HARD CIDER PROCESSING TO MAXIMIZE TANNIN EXTRACTION: EXPLORING THE APPLICATION OF HEAT AND PULSED ELECTRIC FIELD TO APPLE POMACE AND MASH

Abstract

The production of hard cider in the US grew almost 400% between 2011 and 2017 (ATTTB, 2011; ATTTB 2017), with both the largest US producer and the largest number of producers based in NY state. This growth exposed a dearth of “cider” apples, considered a necessary minority component of cider for their contribution of tannins. While orchardists scramble to plant trees to meet demand, cidermakers have tools at their disposal to maximize the extraction of tannins from their limited supply. The skins of many apple varieties contain a reservoir of unextracted tannin lost at pressing. Heat and the application of pulsed electric fields (PEF) can increase extraction into juice, creating more tannic cider. This study was divided into two parts: (1) the treatment of pomace to recover unextracted tannins for addition to cider; and (2) the treatment of apple mash prior to pressing to maximize extraction into juice. Both PEF and heat treatment successfully extracted polyphenols from Red Delicious pomace, with maximum yields of 525 and 1209 GAE per kilogram of pomace, respectively. Pre-press heat and PEF treatment on cider apple mash yielded maximum juice phenolics of 72% and 28% higher than standard processing. Sensory evaluation of these treated tannic ciders blended 30:70 into standard-processed dessert apple ciders found that both were acceptable to consumers, suggesting that either process would be appropriate for processing tannic apples for use in blended ciders.