Selective removal of off-flavors in cold-pressed corn whiskey by coupled nanofiltration-resin treatment
A pilot-scale process that combines nanofiltration with non-polar resin treatment to selectively strip off-flavor compounds from cold-pressed corn whiskey while preserving sugars, acids, and other quality components. Reduces membrane and resin fouling for more efficient operation.
Overview
This solution addresses a key challenge in cold-pressed corn whiskey (CCW) production: the removal of off-flavor compounds without sacrificing the beverage's defining components. The proposed approach pairs nanofiltration (NF) with non-polar resin treatment (R) in a coupled process, using permeate recycling to maximize efficiency. By first isolating low-molecular-weight compounds through NF before exposing them to adsorbent resin, the process achieves selective removal of off-odorants while preserving sugars, acids, phenolics, and minerals critical to the product's standard of identity. This method also reduces membrane and resin fouling compared to either treatment alone, lowering cleaning requirements and extending operational life.
Technical specifications
Process design:
- CCW is fed from a feed tank through a pilot-scale nanofiltration unit
- The permeate, containing low-molecular-weight compounds, passes through a non-polar resin cartridge (e.g., polydivinylbenzene) to strip non-polar odorants
- Both retentate and treated permeate are recycled to the feed tank to enable multiple passes and thorough treatment
- Three membrane molecular weight cut-off sizes and three resins will be evaluated for optimal selectivity
Key features:
- Targets low-molecular-weight (<200 Da), non-polar (log P > 0) odorants responsible for off-flavors
- Minimizes non-selective removal of phenolics and other non-polar quality compounds
- Reduces fouling on both membrane and resin, extending service intervals
- Validated approach: previously demonstrated successful removal of "grapey" flavor compounds from Concord grape juice without affecting anthocyanins, sugars, acids, or minerals
Analytical validation methods:
- GC-MS for off-odorant quantification
- Membrane flux measurements at varying pressure and processing time
- Routine assays for minerals, soluble solids, and phenolics to confirm selectivity
Technology readiness level
This technology is at an early-to-mid stage of development. The underlying NF-R approach has been validated in a related beverage system (Concord grape juice), demonstrating proof of concept for selective off-flavor removal. An initial feasibility study for CCW application is planned over approximately nine months, requiring industry-supplied CCW as feedstock. Optimization of membrane pore size and resin selection for the CCW matrix remains to be completed. The work is positioned for sponsored research collaboration with an industry partner providing raw material and process expertise.
About Cornell University
Cornell University is a comprehensive private, land-grant research university with campuses in Ithaca and New York City, combining significant scale with cross-disciplinary breadth. Industry connects through open-access user facilities and prototyping labs, pilot-scale testbeds, and a research and technology park that provide pathways from discovery to demonstration. A statewide extension network and integration with a major hospital system enable real-world deployment, while a graduate campus embedded in New York City’s tech corridor provides direct access to startups, venture investors, and corporate R&D teams. Research is supported by competitive federal funding from agencies such as the National Science Foundation, National Institutes of Health, the Department of Energy, and the U.S. Department of Agriculture. A dedicated technology transfer office streamlines IP management, licensing, startup formation, and corporate partnerships across campuses.
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