Method and Apparatus for Producing Alcohol with Functional Sugars and Polyphenols Using a Non-Isothermal Saccharification Process

Fermented alcohol that preserves functional sugars and polyphenols by saccharifying grain bran and stalks at low temperatures for an extended period.

This technology involves a method and apparatus for producing alcohol by grinding whole germinated grains mixed with bran and stalks, saccharifying the fiber with complex cellulase at 40–50°C for 6–72 hours, saccharifying the starch with amylase at 60–90°C, and then fermenting with yeast. This non-isothermal process uses two different temperatures to utilize both the husk and the grain as raw materials for the alcohol.

While the revision of liquor tax laws and deregulation have increased demand for diverse alcoholic beverages, existing brewing processes primarily saccharify only the starch, causing grain bran and stalks to be filtered out as waste. Consequently, sugars derived from dietary fiber and antioxidant components in the husks are rarely retained in the final product, and it has been difficult to adjust taste, flavor, and color to consumer preferences without changing the raw materials.

This technology involves heat-treating the ground grain with ethanol before the first saccharification to gelatinize it and control the remaining lignin content. Before fermentation, lignin extracted separately from other bran and stalks is added to achieve the desired polyphenol levels. Using a reactor with a membrane that separates the saccharification and fermentation zones allows only sugars to pass through, preventing yeast from mixing with grain residue, while the grain can be finely ground via colloid milling. Applicable to traditional breweries (makgeolli, yakju), grain spirit production, and small-scale facilities using local grains, this process turns discarded husks into sources of functional sugars like xylose and arabinose, while allowing for the design of specific tastes and colors through controlled lignin input.

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Key Features:

• A step of producing a first intermediate product by primary saccharification of ground germinated grains mixed with bran and stalks using complex cellulase at 40°C–50°C for 6–72 hours
• A step of extracting lignin from germinated grains and other bran and stalks using an ethanol extraction solution and adding it to the second intermediate product before fermentation
• A reactor where the saccharification and fermentation zones are separated by a membrane that selectively allows sugars to permeate through pores smaller than yeast but larger than sugar molecules
• A grinding unit that produces ground grain by pulverizing germinated grains mixed with bran and stalks using a colloid milling method

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