CHARACTERIZATION OF OAT BRAN β-GLUCAN WITH SPECIAL REFERENCE TO EFFICACY STUDY

Abstract

The term bioactive components refers to non essential bio-molecules that are present in foods and exhibits the capacity to modulate one or more metabolic processes which results in the promotion of better health. Bioactive food components also have multiple metabolic activities allowing for beneficial effects in several diseases and target tissues. In millennia, dietary fiber is a collective term used for bioactive components which differ in their chemical structure and physico-chemical properties. It elicits a variety of physiological effects. Thus the present study was designed to characterize the bran of two oat varieties for physico-chemical properties and β-glucan. In addition, oat bran was further characterized for their structural and biological attributes and also observed the effect of processing techniques such as baking, cooking and extrusion on availability of β-glucan content. Moreover, the efficacy study was carried out to observe the effects of different levels of raw and processed oat bran on biological profile of blood of interpretonial Sprauge-Dawley rats. The results showed that bran of Avon variety contained high moisture content, crude fat content, ash content, protein content, crude fiber, TDF, SDF, β-glucan and extractability β-glucan than bran of oat variety Sargodha- 81. Different processing methods were used such as baking, cooking and extrusion to find out the maximum extractability of β-glucan. The extrusion process exhibited the highest extractability of β-glucan (45.37%) followed by cooking (37.28%) and baking methods (32.45%). Thus extrusion process appeared to be the best for the highest extractability of β-glucan. The structural analysis of oat bran of two oat varieties carried out through HPAEC-PAD revealed that the ratio of the amount of soluble and insoluble triose to tetraose in β-glucan fraction was 1.44 and 1.78, respectively for variety Avon. The ratio of the amount of soluble and insoluble triose to tetraose in β-glucan fraction was 1.49 and 1.77 in Sorgadhda-81. The major units were cellotriose and cellotetraose. Other units cellopentaose and hexaoses also existed but in minor fractions. Moreover, the cholesterol, LDL, triglycerides and glucose level reduction was found significantly different when raw and processed oat bran diets fed to normal, hypercholesterolemic and diabetic rats. The highest reduction was recorded when fed on diet containing 30% processed oat bran. The processed oat bran exhibited more reduction as compared to raw oat bran. The diets containing raw and processed oat bran attenuated dyslipidemia and hyperglycemia in rats. Furthermore, addition of 20% oat bran in wheat grits porridge was found to have significant effect (p<0.05) on appearance, mouth feel and overall acceptability. Hence, it could be concluded that substitution of oat bran in amount up to 30% in wheat grits porridge making could produce an acceptable product with a marketability potential. Conclusively, it is suggested that processed oat bran may be introduced in diet based therapy to control lifestyle-related disorders.