Physicochemical, antioxidant and sensory characteristics of cookies supplemented with different levels of spent coffee ground extract

Abstract

Spent coffee grounds (SCG) are the primary by-product of coffee production which still contains functional properties with high natural antioxidant components. It can be extracted using ultrasonic-assisted techniques and then integrated into baking products such as cookies. This research is aimed to measure the physicochemical and sensory acceptability of cookies incorporated with SCG extract. Extraction of SCG was done using water through ultrasonic extraction following incorporated SCG water extract into cookies. Six different formulations were developed using different amount of SCG extract (A-control 0%, B-0.27%, C-0.52%, D-0.80%, E-1.07% and F-1.33%). Physicochemical properties (antioxidant properties, colour profile, texture, moisture, sugar, fat, protein, ash, calorie and texture profile) and the sensory acceptability of SCG extract cookies was observed. Total phenolic content (TPC) was used to quantify the antioxidant content while the antioxidant activity was measured using 2,2-diphenyl-2-picrylydrazyl radical scavenging activity assay (DPPH) and ferric reducing antioxidant power (FRAP) assays. Results show that decreasing in lightness (L*) and yellowness (b*) with the increasing percentage of SCG extract were observed. In contrast with L* and a* value, the b* value of cookies was increased with the increasing percentage of SCG extract. Formulation E (1.07% SCG extract) showed the highest percentage in almost all proximate analysis such as 6.49±0.39 moisture, 2.11±0.22 ash, 20.42±0.74 crude fat, 8.13±0.05 crude protein and 4.37±0.04 crude fibre content. The highest amount of antioxidant content was depicted by the formulation D cookie (1.72±0.04 mg GAE/g). The best antioxidative activity was found in formulation E (7.80±0.27 DPPH inhibition and 0.02 abs by FRAP analysis). Sensory acceptance revealed that formulation E (1.33%) cookies were more accepted by the panellists. It is interesting to note that SCG can serve as one of the ingredients for cookie production that showed significant effects on the physicochemical and organoleptic properties of the final products.