Nyström Laura, Lampi Anna-Maija, Rita Hannu, Aura Anna-Marja, Oksman-Caldentey Kirsi-Marja, Piironen Vieno
Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 27, Latokartanonkaari 11, FI-00014 Helsinki, Finland.
J Agric Food Chem. 2007 Oct 31;55(22):9059-65. doi: 10.1021/jf071579o. Epub 2007 Oct 2.
Rye and wheat bran are excellent natural sources of plant sterols in the diet. Their content, however, may vary according to processing. Thermal (roasting and heating in a microwave oven), mechanical (milling and cryogenic grinding), and enzymatic treatments (hydrolysis with xylanase or beta-glucanase or a mixture of these two enzymes) were performed, and their effect on sterol content, extractability of sterols and the characteristic steryl conjugates of cereals (steryl ferulates, steryl glycosides, and acylated steryl glycosides) were studied. Mechanical and enzymatic treatments increased the apparent sterol content, whereas aqueous processing without enzymes hindered the availability of total sterols, especially from rye bran. Changes were also seen in the amounts of steryl conjugates caused by the enzymatic treatments. On the basis of the results of this study, it can be speculated that a combination of fine particle size and enzymatic processing results in optimal sterol availability in cereal processing.
黑麦麸和小麦麸是饮食中植物甾醇的优质天然来源。然而，它们的含量可能会因加工方式而有所不同。进行了热加工（烘烤和微波炉加热）、机械加工（研磨和低温粉碎）以及酶处理（用木聚糖酶或β-葡聚糖酶或这两种酶的混合物进行水解），并研究了这些处理对甾醇含量、甾醇提取率以及谷物中特征性甾醇共轭物（阿魏酸甾醇酯、甾醇糖苷和酰化甾醇糖苷）的影响。机械处理和酶处理提高了表观甾醇含量，而无酶的水相加工则阻碍了总甾醇的可利用性，尤其是来自黑麦麸的总甾醇。酶处理引起的甾醇共轭物含量也有变化。根据本研究结果，可以推测，在谷物加工中，细粒度与酶处理相结合可实现甾醇的最佳可利用性。
