Hejna Aleksander, Aniśko-Michalak Joanna, Skórczewska Katarzyna, Barczewski Mateusz, Sulima Paweł, Przyborowski Jerzy Andrzej, Cieśliński Hubert, Marć Mariusz
Institute of Materials Technology, Poznan University of Technology, Piotrowo 3, 61-138 Poznan, Poland.
Department of Polymer Technology, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland.
Molecules. 2025 Jun 30;30(13):2809. doi: 10.3390/molecules30132809.
Beer is the third most popular beverage in the world, and its production is distributed uniformly between the biggest continents. Considering the environmental aspects, the utilization of brewing by-products, mainly brewers' spent grain (BSG), is essential on a global scale. The beer revolution, lasting over a few decades, significantly diversified the beer market in terms of styles, and therefore, also its by-products, which should be characterized appropriately prior to further application. Herein, the presented study investigated the unprecedented number of 22 different variants of brewers' spent grain, yielded from the production of various beer styles, enabling their proper comparison. A comprehensive by-product characterization revealed an almost linear relationship (Pearson correlation coefficients exceeding 0.9) between the color parameters (L*, a*, browning index) of beer and generated spent grain, enabling a prediction of BSG appearance based on beer color. Applying wheat or rye malts increased the content of extractives by over 40%, reducing cellulose content by as much as 45%. Thermal treatments of malts (kilning or smoking) also reduced extractive content and limited antioxidant activity, often by over 30%. A lack of husk for wheat or rye reduced the crystallinity index of spent grain by 21-41%, while the roasting of barley efficiently decomposed the less stable compounds and maintained the cellulose crystalline structure. All the analyzed BSG samples were characterized by low volatile emissions and very limited antimicrobial activity. Therefore, their harmfulness to human health and the environment is limited, broadening their potential application range.
啤酒是世界上第三大受欢迎的饮料，其生产在各大洲之间分布均匀。从环境角度考虑，酿造副产品的利用，主要是啤酒糟，在全球范围内至关重要。持续了几十年的啤酒革命在风格上显著丰富了啤酒市场，因此其副产品也应在进一步应用之前进行适当表征。在此，本研究调查了前所未有的22种不同的啤酒糟变体，这些变体来自各种啤酒风格的生产，以便进行适当比较。全面的副产品表征揭示了啤酒的颜色参数（L*、a*、褐变指数）与产生的啤酒糟之间几乎呈线性关系（皮尔逊相关系数超过0.9），从而能够根据啤酒颜色预测啤酒糟的外观。使用小麦或黑麦麦芽可使提取物含量增加40%以上，纤维素含量降低多达45%。麦芽的热处理（烘焙或烟熏）也会降低提取物含量并限制抗氧化活性，通常会降低30%以上。小麦或黑麦缺乏谷壳会使啤酒糟的结晶度指数降低21- 41%，而大麦的烘焙有效地分解了不太稳定的化合物并保持了纤维素晶体结构。所有分析的啤酒糟样品的特点是挥发性排放低且抗菌活性非常有限。因此，它们对人类健康和环境的危害有限，拓宽了其潜在应用范围。
