Composition, physico-chemical properties and the molecular superstructure of dietary fiber preparations of cellan type

Abstract

Dietary fiber preparations of "cellan" type were prepared from apples, white cabbage, sugar beet pulp, soy hulls and wheat bran by treatment with amylolytic and proteolytic enzymes as well as by chemical extractions. Scanning electron microscopic examinations show different morphological structures of the preparations and a high maintenance of native biomolecular superstructure. The content of pectin, protein, polysaccharide-hexoses and -pentoses and the composition of monosaccharides (also after their treatment with 4 or 8% sodium hydroxide) were determined. The cellans possess waterbinding capacities (WBC) between < 10 and > 25 g H2O/g and waterholding capacities between < 10 and > 50 g H2O/g. The WBC is related to the internal surface; it diminishes after treatment with NaOH. The interactions between the cellans and the adsorbed water were characterized by NMR-spin-lattice relaxation time T1. The molecular mobility increases as the water content grows. The T1-values of dried cellans decreased with increasing degree of moisture before drying. The supermolecular structure is comparatively disordered. Only in case of soy cellan a crystalline cellulose-I-modification could be identified by X-ray-diffraction pattern, esp. after NaOH treatment. The low degree of order of cellans was observed in the 13C-NMR spectra, too. Only the soy hull preparation resulted in a spectrum corresponding to well-ordered cellulose. The botanic source has an essential influence on the physico-chemical properties of dietary fiber preparations of cellan type.

Binding of Water, Oil, and Bile Acids to Dietary Fibers of the Cellan Type

“…Protein contents are low in all cellan preparations, and starch has been totally removed. Monosaccharides obtained by partial and total hydrolysis of cellans have been given elsewhere (10,31). Standard DF analysis (19) resulted in a high percentage of total DF in all cellans (68 to 93%), most of which was in the insoluble fraction.…”

“…Then, for removal of lignin, the preparations were extracted with 2% sodium chlorite in 1% acetic acid for 2 h at 20 °C. The cellans were intensively washed with water , dried from n ‐propanol, and milled to a particle size of <1 mm (10).…”

“…To evaluate the physiological significance of the cellular structure in DF of plant origin, it is desirable to investigate DF consisting of nondestroyed cells. Proteins and other digestible materials (e.g., starch) can be removed by treatment with cell‐wall‐permeable enzymes and different chemical extractives (9, 10). The resulting cell structured DFs have been designated as cellans or vesiculary particles.…”

“…The resulting cell structured DFs have been designated as cellans or vesiculary particles. They are interesting, e.g., for chromatography and immobilization (11 − 13) and as potential additives in foods, pharmaceuticals, and cosmetics (10).…”