β-glucan degradation in malting sorghum

Area of Science:

• Agricultural Science
• Food Science
• Biochemistry

Background:

• Beta-glucans are complex carbohydrates found in cereal grains like sorghum.
• High beta-glucan content can negatively impact the processing of malted grains, particularly in brewing.
• Understanding beta-glucan degradation during malting is crucial for optimizing sorghum varieties for malting and brewing.

Purpose of the Study:

• To quantify the reduction in beta-glucan content during the germination of four malting sorghum varieties.
• To investigate the relationship between the final beta-glucan concentration in malt and the filterability of sweet wort.

Main Methods:

• Four malting sorghum varieties were germinated under standard malting conditions.
• Beta-glucan content was measured in the malt samples at specific time points during germination.
• Filterable volume of sweet wort was determined for each malt variety.

Main Results:

• Beta-glucan content decreased by over 50% within 2 days of germination across all tested sorghum varieties.
• Enzymatic digestion was identified as the primary mechanism for beta-glucan reduction.
• A significant inverse correlation was observed: malts with lower beta-glucan content yielded higher filterable wort volumes, and vice versa.

Conclusions:

• Germination effectively reduces beta-glucan levels in malting sorghum through enzymatic activity.
• Sorghum varieties with inherently lower beta-glucan content are more suitable for malting, leading to improved wort separation and potentially better brewing outcomes.
• Selection of low-beta-glucan sorghum varieties can enhance processing efficiency in malting and brewing industries.