Dissolution of Minerals in Beer Lees with Lactic, Tartaric and Citric Acids

摘要

Beer lees are a waste discharged in a large amount from a beer brewery. In order to convert beer lees to valuables, we have carried out the investigations for the production of beer lees charcoal, the evaluation of burning characteristics of the charcoal and the application of the charcoal to water purification. Beer lees contain 4.4% ash and the ash content of beer lees charcoal is 11.9%. The dissolution phenomena of minerals such as Zn, Fe, Ca, Mg, K, Na etc. from beer lees, beer lees charcoal and beer lees ash were examined by using lactic, tartaric and citric acid solutions as a solvent. The organic acids contained in natural plants were used for this purpose, as the dissolved solution may be used for food additives. These acids are considered to be effective for the dissolution of minerals due to the complex formation ability. The obtained results were evaluated using the conditional stability constants between minerals such as Zn, Ca and Mg, and the organic acid.