Refining cider: gathering data and improving data collection tools for cider apple production and selection

Abstract

This research investigated the establishment of a research pipeline for evaluating flavor traits in hard cider, namely phenolic compounds that contribute to bitterness and astringency and the sugar alcohol sorbitol, which contributes to sweetness. Chemical analysis tools, specifically the iron-reactive phenolics (I- RP) assay for total phenolics and the methylcellulose precipitation assay (MCP) for tannin were investigated. Parent material available to the University of Minnesota apple breeding program was surveyed and fermented ciders were produced to study assay efficacy throughout the fermentation process. Both assays are not likely confounded by key chemical constituents of unfermented apple juice, but the I-RP assay is likely more useful in a plant breeding context due to its low cost, specific mode of action, and direct relevance to taste. Attempts were also made to map quantitative trait loci (QTLs) for sorbitol in a cross of two key breeding parents.