ABSTRACT
The nature of and factors effecting sodium interactions with psyllium were investigated in vitro. In a batch extraction system, psyllium mucilage gel retained at least 50% of sodium across a range of concentrations (5-300 mg sodium per g psyllium) and pH (2-10) environments. FTIR and Na NMR analyses of psyllium gels indicated that binding was complex with non-specific multi-site interactions. The potential use of psyllium husk as a binding agent for the reduction of bioavailable sodium was therefore evaluated. The binding of sodium at physiologically relevant conditions (pH 1.2 (stomach) and 6.8 (intestine)) was studied in a gastrointestinal tract (GIT) pH simulated model. Results show consistently high sodium retention (â¼50%) across the GIT model and less than 20% loss of bound sodium under the simulated intestinal pH conditions after repeated washings.
Subject(s)
Digestion , Models, Biological , Plant Mucilage/chemistry , Plantago/chemistry , Prebiotics/analysis , Psyllium/chemistry , Sodium, Dietary/analysis , Binding Sites , Chemical Phenomena , Gastric Juice/chemistry , Gastric Juice/metabolism , Gels , Humans , Hydrogen-Ion Concentration , Intestinal Mucosa/metabolism , Intestine, Small/metabolism , Kinetics , Mouth Mucosa/metabolism , Nuclear Magnetic Resonance, Biomolecular , Psyllium/metabolism , Sodium, Dietary/metabolism , Spectroscopy, Fourier Transform InfraredABSTRACT
Unwashed, sliced, batch-fried potato crisps have a unique texture and are growing in popularity in the UK/EU premium snack food market. In this study, the storage stability of unwashed sliced (high surface starch) potatoes (crisps) fried in regular sunflower oil (SO) or in high oleic sunflower oil (HOSO) was compared over accelerated shelf life testing (45°C, 6 weeks); with and without nitrogen gas flushing. Primary oxidation products (lipid hydroperoxides) were measured with a ferrous oxidation-xylenol orange (FOX) assay and volatile secondary oxidation products (hexanal) were quantified by using solid phase micro-extraction gas chromatography mass spectrometry (HS-SPME-GC/MS). Results revealed that crisps fried in SO were the least stable. Flushing the stored crisps with nitrogen gas proved to be effective in slowing down the oxidation rate after frying with sunflower oil, significantly stabilizing the crisps. However, crisps fried in HOSO were the most stable, with the lowest rate of development of oxidation markers, and this has previously not been shown for crisps with a high free starch content.
