Abstract
Functional food has physiological benefits like health-promoting or disease-preventing properties beyond the basic function of supplying nutrients. Knowledge of such dietary influence projects the global market for functional foods and drinks to reach US$149 billion by 2018. Barley (Hordeum vulgare L.) contains soluble dietary fiber, β-glucans, and act as hypoglycemic and hypocholesterolemic agent. In addition, insoluble fiber in bran of whole barley helps in bowel clearance necessary for colon health. Flaxseed (Linum usitatissimum L.) is a rich source of ω-3 fatty acid, soluble and insoluble fiber, and lignans with a potentiality to reduce the risk of cardiovascular diseases, diabetes mellitus, colon cancer, hypertension, obesity and constipation. Considering the wide acceptability of soup by consumers of all age groups, its convenient cooking and fast growing market, the present study was aimed to develop and characterize barley flaxseed based functional dry soup mix (BFSM). D-optimal mixture design in response surface methodology (RSM) following numerical optimization was used to obtain the optimum amount of whole barley flour (WBF) and roasted flaxseed powder, FP (made by roasting and grinding whole flaxseed), to be mixed with certain predetermined amount of flavoring to develop optimized soup premix (OSP). In order to minimize the caking behavior, anticaking agent, i.e., tricalcium phosphate (TCP) in optimum amount, obtained by one factor RSM, was added to OSP to finally obtain BFSM. Full characterization of BFSM with respect to its chemical composition, moisture sorption characteristics, calorific value, and physical, optical, thermal, rheological, sensory and functional properties were carried out.
Qualities of vacuum packed BFSM while stored at ambient, mildly accelerated and refrigerated condition were also evaluated.
Optimum formulation of BFSM was arrived as 46.296% WBF, 23.148% FP, and 30.555% seasoning (i.e., flavoring plus TCP). BFSM was easy to prepare with simple technique. It was free flowing powder with desirable particle size distribution, caking and handling behavior, and acceptable color; all were comparable or superior to commercial soup mix. BFSM was nutritious with reasonable calorific value, and easily dispersible to prepare soup of desired consistency with acceptable sensory quality scores. It was free of antinutritional risk. BFSM was good source of phenolics with adequate antioxidant activity, -3 fatty acid (≈0.4 g in one serving of 250 ml of 8.64% BFSM), and β-glucans. In vitro and in vivo glycemic indices categorized BFSM as low glycemic supporting its use by diabetic. As per the norm of USFDA (2008), BFSM containing ≈ 0.9 g β-glucans/serving could be called as ‘health food’.
Soup prepared with BFSM behaved as shear thinning liquid and followed Herschel-Bulkley model. Peleg model could satisfactorily describe its moisture sorption isotherm and indicated that BFSM absorbs lower moisture than commercial soup mix ensuring its better keeping quality. Vacuum packed BFSM could maintain its organoleptic acceptability in full up to 60 days of storage. Extension up to 120 days required refrigerated storage at 4±1 °C.
Keywords: Functional soup mix, functional food, soup from barley and flaxseed, low glycemic food, soup containing β-glucans, barley, flaxseed
