College of Food Science and Technology, Nanjing Agricultural University, Nanjing, PR China.
J Sci Food Agric. 2024 Aug 15;104(10):6196-6207. doi: 10.1002/jsfa.13455. Epub 2024 Mar 22.
Millet bran (MB), a byproduct of millet production, is rich in functional components but it is underutilized. In recent years, researchers have shown that fermentation can improve the biological activity of cereals and their byproducts. This study used Bacillus natto to ferment millet bran to improve its added value and broaden the application of MB. The bioactive component content, physicochemical properties, and functional activity of millet bran extract (MBE) from fermented millet bran were determined.
After fermentation, the soluble dietary fiber (SDF) content increased by 92.0%, the β-glucan content by 164.4%, the polypeptide content by 111.4%, the polyphenol content by 32.5%, the flavone content by 16.4%, and the total amino acid content by 95.4%. Scanning electron microscopy revealed that the microscopic morphology of MBE changed from complete and dense blocks to loosely porous shapes after fermentation. After fermentation, the solubility, water-holding capacity, and viscosity significantly increased and the particle size decreased. Moreover, the glucose adsorption capacity (2.1 mmol g), glucose dialysis retardation index (75.3%), and α-glucosidase inhibitory (71.4%, mixed reversible inhibition) activity of the fermented MBE (FMBE) were greater than those of the unfermented MBE (0.99 mmol g, 32.1%, and 35.1%, respectively). The FMBE presented better cholesterol and sodium cholate (SC) adsorption properties and the adsorption was considered inhomogeneous surface adsorption.
Fermentation increased the bioactive component content and improved the physicochemical properties of MBE, thereby improving its hypoglycemic and hypolipidemic properties. This study not only resolves the problem of millet bran waste but also encourages the development of higher value-added application methods for millet bran. © 2024 Society of Chemical Industry.
小米糠是小米加工的副产品，富含功能性成分，但利用率较低。近年来，研究人员发现发酵可以提高谷物及其副产品的生物活性。本研究采用纳豆芽孢杆菌发酵小米糠，以提高其附加值，拓宽小米糠的应用。测定了发酵小米糠的小米糠提取物（MBE）的生物活性成分含量、理化性质和功能活性。
发酵后，可溶性膳食纤维（SDF）含量增加了 92.0%，β-葡聚糖含量增加了 164.4%，多肽含量增加了 111.4%，多酚含量增加了 32.5%，黄酮含量增加了 16.4%，总氨基酸含量增加了 95.4%。扫描电子显微镜显示，发酵后 MBE 的微观形态由完整致密的块状变为疏松多孔的形状。发酵后，MBE 的溶解度、持水能力和粘度显著增加，粒径减小。此外，发酵小米糠提取物（FMBE）的葡萄糖吸附能力（2.1mmol/g）、葡萄糖透析迟滞指数（75.3%）和α-葡萄糖苷酶抑制活性（71.4%，混合可逆抑制）大于未发酵小米糠提取物（0.99mmol/g、32.1%和 35.1%）。FMBE 具有更好的胆固醇和胆酸钠（SC）吸附性能，吸附被认为是不均匀的表面吸附。
发酵提高了 MBE 的生物活性成分含量，改善了其理化性质，从而提高了其降血糖和降血脂的性能。本研究不仅解决了小米糠浪费的问题，而且鼓励开发更高附加值的小米糠应用方法。© 2024 化学工业协会。
