In vitro binding of lipid [olive oil and ghee] with chitosan under the conditions mimicking the gastrointestinal tract

An in vitro binding study of chitosan with lipid was carried out under the conditions mimicking the gastrointestinal tract, with special reference to the pHs of stomach and duodenum. Olive oil and ghee were used to represent lipid components of diet, and chitosan [treated and untreated] was used to bind with the mentioned lipids. The results obtained from this study showed that the treated chitosan gave better binding to lipid [olive oil or ghee] compared with the untreated chitosan. Chitosan [treated or untreated] showed higher affinity towards olive oil than ghee. Incubation period accompanied with shaking also influenced the binding of lipid to chitosan and the maximum binding was attained after 2.5 hrs of incubation. The ratio of chitosan to lipid used was found to affect the amount of lipid bound per gram of chitosan. Olive oil bound per gram of chitosan was 4.6 +/- 0.28 -7.1 +/- 0.14 g while ghee was 3.6 +/- 0.28 - 6.2 +/- 0.28 g under 1:100 experimental ratio of chitosan to lipid, and shaking for 2.5 hrs at physiological temperature of 37°C. Consideration of pKa value suggests that the predominated form of chitosan at duodenal pH [-7.0] is uncharged chitosan, which is precipitated along with the lipid adsorbed onto it

Inhibitory effect of antioxidants on ferric nitrilotriacetic acid chelate mediated peroxidation of methyllinoleate

Antioxidants, namely mannitol, gallic acid, quercetin, Alpha-tocopheryl acetate, and ascorbic acid, were evaluated for their inhibitory activities on the peroxidation of methyllinoleate [ML] induced by 1:2 ferric-nitrilotriacetic acid [Fe [III] [NTA] 2] chelate. The thiobarbituric acid reactive substance [TBARS] assay was used to measure the inhibitory effect of the antioxidants [AOXs]. The results of this study have revealed that Fe [III] [NTA] 2-mediated peroxidation of ML was inhibited by each of the antioxidants used and the inhibition was concentration dependent. The decreasing order of inhibition of peroxidation of ML by the antioxidants at 1 mM concentration was found to be as follows: gallic acid > quercetin > mannitol > tocopheryl acetate > ascorbic acid. The probable causes of the observed decreasing order of inhibitory effect for the studied antioxidants have also been discussed