Process optimization, physicochemical and sensory acceptability analysis A Smooth drink made from fenugreek (Trigonella foenum graecum) blended with stevia sweetener (Stevia rebuadiana)

Abstract

Fenugreek (Trigonella foenum-graecum L.) is a nutritionally rich and medicinally valuable seed, but its strong bitterness and odor limit its use in beverage products. This study aimed to optimize processing conditions for developing a fenugreek-based smooth drink sweetened with stevia (Stevia rebaudiana) and to evaluate its physicochemical properties and sensory acceptability. Fenugreek seeds were subjected to soaking and roasting pre-treatments to reduce bitterness and anti-nutritional factors. The treated fenugreek flour was blended with stevia sweetener at different ratios. A Response Surface Methodology (RSM) with a Central Composite Rotatable Design (CCRD) was applied to optimize three processing variables: soaking time, roasting time, and blending ratio. The responses analyse were total soluble solids (°Brix), titratable acidity, and turbidity, along with proximate composition and sensory attributes. Results showed that soaking and roasting significantly improved the drink’s quality by reducing undesirable flavors and enhancing nutritional composition. The optimized blend demonstrated improved protein and fiber content and acceptable physicochemical characteristics. Sensory evaluation indicated that the optimized fenugreek–stevia smooth drink had better taste, aroma, and overall acceptability compared to untreated formulations. In conclusion, proper pre-treatment of fenugreek combined with natural stevia sweetener can produce a nutritious, palatable, and functional smooth drink, offering potential for value-added beverage development.