In-Vitro Studies on Functional Properties of Selected Natural Dietary Fibers

Abstract

In-vitro experiments were conducted to provide predictive indices for the hypoglycemic effect of ashgourd, radish, pea peel, and cardamom peel fibers and its action of particle size and pH (related to human physiology) on the major functional properties. Ashgourd and radish fibers demonstrated significantly (p ≤ 0.05) higher water binding capacity and swelling capacity in stomach pH, i.e., 1.8; whereas pea peel and cardamom peel fibers exhibited higher hydration capacity at duodenal pH, i.e., 8.7. Ashgourd fiber (30 mesh) showed higher glucose adsorption capacity (452.1 µm/g) and exhibited maximum retarding effect on the flow of glucose across the dialysis bag for 12 h in comparison with other fiber sources. The 30 mesh (250-380 µm) and 60 mesh (150-230 µm) fiber particles showed better hydration properties as well as hypoglycemic effect as compared to 100 mesh (40-110 µm) particles. These fibers showed an excellent performance in relation to functional properties and hypoglycemic effect thus can be incorporated as low calorie bulk ingredient in high fiber foods to reduce calorie level and to help in controlling blood glucose concentration.

Study on Functional Properties of Physically Modified Dietary Fibres Derived from Defatted Rice Bran

“…Similar conclusions have been reported by Prachi & Premavalli (2011) who studied the effect of particle size and pH on WBC in the pea peel and cardamom fiber containing higher insoluble dietary fiber component similar to those studied by Gorecka, Lampart-Szczapa, Janitz, & Sokolowska (2000) results. Considering the results achieved in the present study, it can be assumed that microwave and extrusion treatments of dietary fiber improve its WBC at neutral and alkaline pH while, ultrasonic treatment improve it at acid pH.…”

“…These results revealed that the extruded and untreated DRBDF having large particle sizes (700 and 685µm respectively) exhibit a significant (p≤0.05) higher SWC at neutral pH (2.51ml/g and 2.64ml/g respectively) and in the alkaline pH (3.66ml/g and 3.49ml/g respectively) as compared to others treated DRBDF with small particles. Micronization and ultrasonic treatments significantly decreased the particle size consequently leading to the destruction of fiber matrix and low SWC, Sangnark & Noomhorm (2004), and Prachi & Premavalli (2011). All these DRBDF showed lower SWC in acidic pH i.e., 1.8, as compared to alkaline or neutral pH (Table 2).…”

“…The high WBC of all DRBDF in alkaline pH (pH 8.7, duodenum) revealed that these fibers have higher insoluble fibers component such as cellulose, which could bind more water at alkaline pH (Prachi & Premavalli, 2011). Similar conclusions have been reported by Prachi & Premavalli (2011) who studied the effect of particle size and pH on WBC in the pea peel and cardamom fiber containing higher insoluble dietary fiber component similar to those studied by Gorecka, Lampart-Szczapa, Janitz, & Sokolowska (2000) results.…”

“…Soluble fibers are usually made up pectin and soluble hemicellulose. These components could bind more water in acidic pH (Prachi & Premavalli, 2011).…”

Functional and physiological properties of total, soluble, and insoluble dietary fibres derived from defatted rice bran

“…After 60 min the rate of glucose diffusion across the dialysis membrane increased faster for these fibers than SDF and their GDRI were lower because the insoluble fibers with lower viscosity (2.11 mPa.s at 3 %) did not contribute toward the increase in viscosity. Moreover, due to their complete imbibitions and saturation, further retention of glucose could not occur Gupta and Premavalli (2011) causing the diffusion rate to increase resulting in rising levels of glucose in the dialysate.…”