title: The partitioning of water in aggregates of undigested and digested dietary particles.
abstract: The hydration of fibre particles derived from wheat and wood was quantified, before and after in vitro digestion, and compared with fibre particles from the colonic digesta of pigs and from human faeces. Total water and the extra- and intra-particulate water components were determined using a combination of centrifugation, drying, gas pycnometry and image analysis. The water of saturation (WS) of wood particles and AllBran® measured after in vitro digestion was up to double that of wheat fibres after in vitro digestion, and increased with particle size and loss of soluble material, but was not associated with the chemical composition of the fibres. Fibre that had undergone in vitro gastric digestion and that had been recovered from the colon or faeces, sequestered about 3% of the Ws into intra-particulate spaces, the remainder occupying extra-particulate spaces. The authors speculate that large quantities of fibre must be eaten to sequester toxins that locate into the intra-particulate space.
authors.affiliation: Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand. a.hardacre@massey.ac.nz
authors.forename: Allan K
authors.initials: AK
authors.lastname: Hardacre
authors.forename: Sia-Yen
authors.initials: SY
authors.lastname: Yap
authors.forename: Roger G
authors.initials: RG
authors.lastname: Lentle
authors.forename: Patrick W M
authors.initials: PW
authors.lastname: Janssen
authors.forename: John A
authors.initials: JA
authors.lastname: Monro
mesh_terms: D004043:Dietary Fiber / Q000032:analysis* / Q000378:metabolism; D004063:Digestion; D005243:Feces / Q000737:chemistry; D006801:Humans; D010316:Particle Size; D028223:Pinus / Q000737:chemistry* / Q000378:metabolism; D014908:Triticum / Q000737:chemistry* / Q000378:metabolism; D014867:Water / Q000378:metabolism*; D014934:Wood / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004043:Dietary Fiber; D014867:Water
keywords: Digesta; Extra- and intra-particulate water; Insoluble fibres; W(S); WE; WI; Water holding capacity; dry weight basis; dwb; the proportion of extra particulate water; the proportion of intra-particulate water; the weight of water in the saturated fibre; wet weight basis; wwb