Quantification of fructans in cereal-based bioethanol stillage based on a simplified analytical method

Background and Objectives: Cereal-based bioethanol stillage, the main by-product of industrial bioethanol production, is a potential substrate for fructans. However, the quantification of fructans in such complex sample matrices is still a challenge for the corresponding analytics to be overcome to allow for the identification and utilization of such unused fructan sources. Especially a possible utilization or rather the corresponding process development requires appropriate analytics first. Thus, this paper aims to develop and apply a method for fructan quantification in bioethanol stillage using common a high-performance liquid chromatography–refractive index detector. Findings: A new approach for fructan quantification is presented allowing for simple fructan determination in bioethanol stillage for comparably high sample throughput. The developed analytical method performs fructan quantification by means of fructose- and glucose-equivalent determination after targeted acidic hydrolysis adapted to the respective sample matrix. On the basis of this method, up to 2.5% of fructans were found in the dry matter of cereal-based bioethanol stillage. Conclusion: Cereal-based bioethanol stillage is assessed to be a potential source of fructans. The presented analytical method can be the basis for respective process development and, thus, may contribute to a higher-value utilization of stillage. Significance and Novelty: According to current knowledge, no determination of fructans in stillage or corresponding analytical methods have been published so far.