International Survey on Dietary Fiber: Definition, Analysis, and Reference Materials

Abstract

An international survey was conducted to get the views of 147 professionals in the field on the definition of dietary fiber. The survey also solicited opinions on analytical methods for nutrition labeling, quality control, and nutrition research. The survey finds that dietary fiber is generally defined as polysaccharides and lignin that are not hydrolyzed by human alimentary enzymes. Support is strong for expansion of the definition to include oligosaccharides that are resistant to hydrolysis by human alimentary enzymes. Among techniques for nutrition labeling and quality control, enzymatic-gravimetric methods get the highest support. For nutrition research, more detailed methods such as gas-liquid chromatography and liquid chromatography were considered more appropriate. Respondents support labeling of total, soluble, and insoluble dietary fiber or total dietary fiber alone as sufficient for nutrition labeling of food packages. However, for nutrition research, detailed analytical methods, improvements in accuracy (i.e., closer simulation of in vitro techniques to conditions of human gastrointestinal tract), and improvements in precision and simplicity are suggested. Less than 20% of the participants use reference materials for dietary fiber analysis.

Indigestible fraction of edible marine seaweeds

“…For red seaweeds, IIF was mainly composed of neutral sugars plus a trace of uronic acid (145–174 g kg −1 ) and a small amount of klason lignin (32–37 g kg −1 ), lower than the previous values estimated in IDF from seaweeds 9. The analyses of dietary fibre according to the AOAC method19, 33 are performed at temperatures (60–100 °C) that differ from those in the human gastrointestinal tract; moreover, pH conditions (4.5–7.5) do not reproduce the acid pH in the stomach (1–1.5). However, temperature, pH, enzymes and incubation times in the IF analyses mimic physiological digestive conditions 22.…”

Aloe arborescens supplementation in cat diet: evaluation of effects by in vitro gas production technique

“…An extruded diet alone or with addition of three different levels (0.7, 1.6 and 3.2%) of Aloe arborescens powder (whole lyophilised plant; HDR Company, Capriati al Volturno, Caserta, Italy) was analysed for crude protein, ether extract and ash (AOAC 2005), starch (Martillotti et al 1987), the reserve carbohydrates were calculated from difference: [100 -(water -CP -EE -TDF -Ash)]. TDF, soluble dietary fibre (SDF) and insoluble dietary fibre (IDF) contents (Prosky 1990;Lee & Prosky 1995).…”

Production of Healthy Snacks From Barley, Chickpea, Lettuce Seeds and Herb Distributed in Egypt

“…Total dietary fiber was determined by the methods described by Prosky (1988). Soluble and non-soluble dietary fiber was determined according to Lee and Prosky (1995).…”