Process Optimisation of Dolichos lablab Peel Powder and Buckwheat Flour incorporated Biscuits using Response Surface Methodology
Abhinay Shashank, Guruprasad N, Durga Shankar Bunkar, SK Goyal, Amrita Poonia
The present study was carried out to partially replace refined wheat flour with buckwheat flour and Dolichos lablab peel powder to get benefit of their nutraceutical properties and also to utilize Dolichos lablab peel, which would otherwise be a waste. The composition of the various ingredients like refined wheat flour (RWF), buckwheat flour (BWF) and Dolichos lablab peel powder (DLPP) was optimised using response surface methodology (RSM) using Minitab 17 taking into consideration 20 set of experiments and observing the responses on various parameters like hardness, fracturability, colour and appearance, crispiness, flavor and overall acceptability. The optimized biscuit had 45 % refined wheat flour, 10.65 % Dolichos lablab peel powder and 30 % buckwheat flour apart from other ingredients like salt, sugar etc. and the overall acceptability of the biscuit came out to be 8.17. The optimized biscuits were analysed for their nutritional and physicochemical properties. The moisture, protein, fat, ash, crude fibre and carbohydrate content were calculated to be 2.73 %, 8.052%, 15.90 %, 1.48 %, 5.25 % and 66.61 % respectively. The thickness of the optimized biscuits came out to be 0.70 cm, the diameter of the biscuit came out to be 5.80 cm and the spread ratio was 8.32. The shelf life of biscuit was studied at a storage temperature of 37 ℃ for a period of 45 days at an interval of 15 days based on various parameters like moisture, free fatty acid, peroxide value and hydroxy methyl furfural (HMF) content. There was no significant changes in moisture content of biscuits stored at ambient temperature conditions. The change in lipid peroxidation as measured by peroxide value and free fatty acid value were found to increase during storage period. Peroxide value found to increase from 6.967 to 17.905 meq O2/Kg fat, while free fatty acid increased from 1.22 to 1.6532 % oleic acid respectively. It was observed that with increase in storage time the formation of HMF increased.