Comparison of the Phenolic Profiles of Juice and Cider Derived from Machine- and Hand-harvested ‘Brown Snout’ Specialty Cider Apples in Northwest Washington

• Published in: HortTechnology (Alexandria, Va.) Va.), 2019-08, Vol.29 (4), p.423-433
• Main Authors: Alexander, Travis R., Collins, Thomas S., Miles, Carol A.
• Format: Article
• Language: English
• Subjects: apples; catechin; catechin equivalents; ciders; discriminant analysis; fruits; labor; Malus domestica; malus ×domestica; manual harvesting; mass spectrometry; mechanical harvesting; shake-and-catch; sweating; titration; ultra-performance liquid chromatography
• ISSN: 1063-0198; 1943-7714
• DOI: 10.21273/HORTTECH04342-19

‘Brown Snout’ cider apple ( Malus ×domestica ) is desired by cider makers for its relatively high levels of phenolics, and over-the-row machine harvesting of ‘Brown Snout’ has been demonstrated to provide similar yield to hand harvest at a significantly lower cost. The purpose of this study was to determine if there is a measurable impact of harvest method on the phenolic profile of ‘Brown Snout’ juice and cider to better inform equipment adoption recommendations. Using a redox titration assay, the titratable tannin content (± SE) of juice (0.19% ± 0.01%) and cider (0.19% ± 0.01%) were found not to differ due to harvest method. Using a protein precipitation assay, juice from machine-harvested fruit was found to have lower levels of total tannins [231 ± 36 mg·L −1 catechin equivalents (CE)] than juice from hand-harvested fruit (420 ± 14 mg·L −1 CE). However, the total tannins of cider did not differ due to harvest method, the overall average for machine and hand harvest was 203 ± 22 mg·L −1 CE. The total phenolics of juice and cider did not differ due to harvest method (1415 ± 98 mg·L −1 CE and 1431 ± 73 mg·L −1 CE, respectively). Discriminant analysis based on an average of 33 tentatively identified phenolic compounds, as measured by ultra-high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry, showed no separation due to harvest method in juice or cider. In conclusion, over-the-row machine harvesting of ‘Brown Snout’ resulted in a final product of similar quality at reduced labor costs, and thus shows potential for increasing the commercial sustainability of cider apple operations.