title: Chemical characterization of Klason lignin preparations from plant-based foods.
abstract: To analyze the accuracy of the Klason lignin method as applied for the determination of lignin contents in plant based-food products, Klason lignin preparations from curly kale, pears, whole wheat grains, and corn bran were chemically characterized. Characterization included routine ash and protein determinations and the extraction of fat/waxes as well as cutin/suberin depolymerization and extraction of the liberated monomers. Fat/wax and cutin/suberin amounts in the Klason lignin preparations were determined gravimetrically, and their compositions were analyzed by using GC-MS. Typical fat, wax, and cutin (and suberin) constituents such as saturated and unsaturated fatty acids, hydroxy and/or epoxy fatty acids, and phenolic acids were identified in all samples, whereas the detection of long-chain hydrocarbons, alcohols, and ketones, sterols, stanols, and dioic acids was dependent on the sample analyzed. Estimation of the contribution of non-lignin compounds to the Klason lignin contents reduced the noncorrected Klason lignin contents of the insoluble fibers from 28.7% (kale), 22.8% (pear), 14.8% (wheat), and 9.9% (corn) to maximum lignin contents of 6.5% (kale), 16.4% (pear), 4.9% (wheat), and 2.3% (corn). These data demonstrate that certain commonly used statements such as "cereal brans are highly lignified" need to be revised.
authors: Department of Food Science and Nutrition-CFANS, University of Minnesota, Twin Cities Campus, 1334 Eckles Avenue, St. Paul, Minnesota 55108, United States. mbunzel@umn.edu
authors: Mirko
authors: M
authors: Bunzel
authors: Anne
authors: A
authors: Schüssler
authors: Gérard
authors: G
authors: Tchetseubu Saha
mesh_terms: D001937:Brassica / Q000737:chemistry; D004043:Dietary Fiber / Q000032:analysis; D005189:False Positive Reactions; D005638:Fruit / Q000737:chemistry; D006358:Hot Temperature; D008031:Lignin / Q000032:analysis* / Q000737:chemistry; D010945:Plants, Edible / Q000737:chemistry*; D031989:Pyrus / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D013464:Sulfuric Acids; D014908:Triticum / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
chemical_list: D004043:Dietary Fiber; D013464:Sulfuric Acids; D008031:Lignin; C033158:sulfuric acid