2018 ASHS Annual Conference

In this study, the polyphenol profiles of juice and cider derived from over-the-row machine- and hand-harvested ‘Brown Snout that were ambient stored (56 °F) 0-4 weeks postharvest were compared utilizing analytical chemistry. Variation due to harvest method was found to be non-significant (P > 0.05) for all quality characteristics [specific gravity (SG), pH, titratable acidity (TA), and tannin content] measured on juice and cider samples. The SG, pH, and TA of juice samples significantly differed due to duration of ambient storage (P = 0.01, P = 0.04, and P = 0.01), fruit most likely underwent dehydration over time. The SG, pH, and TA of cider samples did not significantly differ due to duration of storage (0.999 ± 0.000, 3.52 ± 0.01, 0.63% ± 0.02%), which was expected as these three parameters were artificially adjusted for controlled fermentation. The tannin content of juice and cider samples did not differ due to harvest method or duration of storage (0.19% ± 0.01%). The ABV of cider samples differed due to duration of storage (P = 0.02). Fruit that was pressed immediately after harvest (0 weeks storage) on average had ABV of 5.39% ± 0.19%, whereas fruit that was stored under ambient conditions for 4 weeks had on average 6.14% ± 0.16% ABV; a higher sugar content in the stored fruit allowed for greater alcohol production by yeast. Total phenolics and total tannins [measured in catechin equivalents (CE)] of juice and cider samples did not significantly differ due to duration of ambient storage time. Total phenolics of juice samples did not significantly differ due to harvest method (1415 ± 98 mg·L^-1 CE). Total tannins of juice samples did significantly differ due to harvest method (P < 0.0001). Machine-harvested juice samples had lower levels (231 ± 36 mg·L^-1 CE) of total tannins than hand-harvested juice samples (420 ± 14 mg·L^-1 CE). Total phenolics and total tannins of cider samples did not significantly differ due to harvest method (1431 ± 73 mg·L-1 CE and 203 ± 22 mg·L-1 CE). The harvest cost savings provided by over-the-row machine-harvesting of ‘Brown Snout’ appears to come at the cost of lower polyphenol content in the final cider product. Modification of pressing methodology to maximize extraction of phenolic compounds from machine-harvested fruit or the addition of exogenous phenolic compounds to collected juice could serve to minimize the observed reduction in cider polyphenol content.