Decimo Marilù, Quattrini Mattia, Ricci Giovanni, Fortina Maria Grazia, Brasca Milena, Silvetti Tiziana, Manini Federica, Erba Daniela, Criscuoli Franca, Casiraghi Maria Cristina
Institute of Sciences of Food Production, National Research Council of Italy, Milan, Italy.
Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy.
AMB Express. 2017 Nov 16;7(1):205. doi: 10.1186/s13568-017-0506-y.
Sustainable exploitation of agro-industrial by-products has attracted great interest in cereal bran valorization. In this research, a polyphasic approach has been carried out to characterize maize bran at microbiological and chemical level during a sourdough like fermentation process, in order to enhance its technological and nutritional properties. Autochthonous microbiota was isolated at different refreshment steps and subjected to identification and molecular characterization. Fermentation was characterized by a rapid increase in lactic acid bacteria and yeasts, with a co-dominance, at the initial stage, of Weissella spp., Pediococcus spp. and Wickerhamomyces anomalus. At the end of the fermentation, a natural selection was produced, with the prevalence of Lactobacillus plantarum, Lactobacillus brevis and Kazachstania unispora. This is the first time that a specific association between LAB and yeasts is reported, during the maize bran fermentation process. Enzymatic activities related to this microbial consortium promoted a "destructuration" of the fiber fraction, an increase in soluble dietary fiber and a reduction of phytic acid content. Our data also evidenced a noticeable increment in ferulic acid. The results obtained indicate that fermentation processes represent an efficient biotechnological approach to increase nutritional and functional potential of maize bran. Moreover, the characterization of microbiota involved in natural fermentation process will allow the selection of specific biotypes, with appropriate metabolic and enzymatic activities, to conduct "tailored" fermentation processes and improve brans or whole-meal flours from both nutritional and technological points of view.
农业工业副产品的可持续开发引起了人们对谷物麸皮增值的极大兴趣。在本研究中，采用了多相方法，在类似酸面团的发酵过程中，从微生物学和化学层面表征玉米麸皮，以增强其工艺和营养特性。在不同的复壮步骤中分离出本地微生物群，并进行鉴定和分子表征。发酵的特点是乳酸菌和酵母菌迅速增加，在初始阶段，魏斯氏菌属、片球菌属和异常威克汉姆酵母共同占主导地位。在发酵结束时，产生了自然选择，植物乳杆菌、短乳杆菌和单孢卡扎奇酵母占优势。这是首次报道在玉米麸皮发酵过程中乳酸菌和酵母菌之间存在特定关联。与这种微生物群落相关的酶活性促进了纤维部分的“解构”、可溶性膳食纤维的增加和植酸含量的降低。我们的数据还证明了阿魏酸有显著增加。所得结果表明，发酵过程是提高玉米麸皮营养和功能潜力的一种有效生物技术方法。此外，对参与自然发酵过程的微生物群进行表征，将有助于选择具有适当代谢和酶活性的特定生物型，从营养和工艺角度进行“定制”发酵过程，并改善麸皮或全麦粉。
