## 2 Materials and Methods
### Physicochemical Parameters Analysis  
2.3.1. Proximate, Colour and Mineral Analysis  
Proximate analysis consisting of moisture, ash, crude protein, crude fat, and crude fibre evaluation of tuber powder extracts of WFSP, and WFP was carried out by following the method of [PERSON] and [PERSON] [27] with slight modifications. The refined powder of sweet potato was taken into three separate China dishes, weighed, and placed in an air-forced draft oven (Model: DO-1-30/02, PCSIR, Pakistan) at 105 \(\pm\) 5 \({}^{\circ}\)C till constant weight. Equation (1) was used to calculate the percentage of moisture. For ash content analysis (Method No. 942-05) [27], the sample was taken in pre-weighed crucibles, charred on a burner till the end of the fume's appearance. Then, the sample was subjected to direct incineration in a muffle furnace (MF-1/02, PCSIR, Pakistan) at 550-600 \({}^{\circ}\)C after charring until a white greyish residue. Equation (2) was used to calculate the percentage of ash content. Similarly, for crude protein content (Method No. 984-13) [2], 2 g extracts were firstly digested with 30 mL concentrated sulphuric acid (H\({}_{2}\)SO\({}_{4}\)) in the presence of digestion mixture for 4-5 h and then diluted to 250 mL with distilled water (d.H\({}_{2}\)O). Distillation of 10 mL diluted sample and 10 mL of 40% sodium hydroxide solution was conducted by distillation apparatus. Ammonia (NH\({}_{3}\)) was liberated and collected in 2% boric acid solution (4 g boric acid and 100 mL solution) containing methyl red as an indicator. Then samples containing ammonium borate were titrated against a 0.1 N sulphuric acid solution till a golden-brown endpoint. \[Moisture\ (\%)=\frac{Weight\ of\ original\ sample\ (\mathrm{g})- weight\ of\ dried\ sample\ (\mathrm{g})}{Weight\ of\ original\ sample\ (\mathrm{g})}\times 100 \tag{1}\]  
\[Ash\ (\%)=\frac{Weight\ of\ residue\ (\mathrm{g})}{Weight\ of\ original\ sample\ (\mathrm{g})}\times 100 \tag{2}\]  
The crude fibre content of the sample was determined by Labcenco Fibertech (Labcenco Corporation, Kansas City, MO, USA) as described in AOAC (2005) Method No. 978-10 [27]. Briefly, 1 g of moisture and the fat-free sample was taken in a 1000 mL beaker, and 200 mL of diluted (1.25%) sulphuric acid was added. Samples were digested by boiling for 30 min. It was filtered (via suction apparatus), and residues were washed with hot water at least three times until they became acid-free. This method was repeated thrice until samples became alkali-free. Residues were transferred into a pre-weighed crucible and dried in an oven at 70-80 \({}^{\circ}\)C until a constant weight was attained. Finally, residues were charred on a burner and ignited in a muffle furnace at 550 \({}^{\circ}\)C for 5-6 h and cooled in a desiccator and weighed. The loss in weight during incineration represented the weight of crude fibre in the sample from which the percentage present in sample was calculated by using Equation (3). Similarly, crude fat (Method No. 920.39) and nitrogen-free extract (NFE) of WFSP and WFP were determined by Equations (4) and (5), respectively. The total energy was measured using Atwater conversion factors by following Equation (6). [28]:  
\[Crude\ fiber\ (\%)=\frac{Loss\ of\ weight\ of\ sample\ during\ as\hing\ (\mathrm{g})}{Weight\ of\ original\ sample\ (\mathrm{g})}\times 100 \tag{3}\]  
\[Crude\ fat\ (\%)=\frac{Weight\ of\ petroleum\ ether\ extract\ (\mathrm{g})}{Weight\ of\ original\ sample\ (\mathrm{g})}\times 100 \tag{4}\]  
\[NFE\ (\%)=(Crude\ protein+Crude\ fat+Ash+Moisture+Crude\ fiber)\times 100 \tag{5}\]  
\[Total\ energy\ \left(\frac{\mathrm{kcal}}{100}\mathrm{g}\right)=(4\times protein )+(9\times fat)+(4\times carbohydrate) \tag{6}\]  
Similarly, the colour analysis of WFSP and WFP was performed using a CIELab Colour Meter. Lightness (L'), \"a\"*\" (-a redness; +a greenness), and \"b\"*\" (-b yellowness; +b blueness) under constant lighting conditions using a white tile control. The mineral profiling of the samples was performed by following the [PERSON] et al.