**2. Materials and method**

The materials, mango endocarp, melon husk, and moringa seed pod were sourced for at Kwali Area Council, an agrarian community of the Federal Capital Territory of Nigeria. Each of the biomass materials was subjected to compositional analysis using the gravimetric method reported [19].

#### **2.1 Extractives**

About 2.5 g of each of the dried samples was extracted with 150 mL acetone using a Soxhlet extractor setup. After extraction, the samples were air-dried at room temperature. The extracted samples were put in a convection oven at 105°C to achieve a constant weight. The %(w/w) of the extractives content was evaluated as the difference in weight between the raw extractive-laden biomass and extractivefree biomass [20–22].

#### **2.2 Hemicellulose**

About 150 mL of 0.5 M NaOH was added to 1 g of extractives-free dried biomass in a 250-ml Erlenmeyer flask. The mixture was boiled for 3.5 h, allowed to cool, filtered, and washed with distilled water until a neutral pH was obtained. The residue was dried to a constant weight at 105°C in a convection oven. The difference between the sample weight before and after this treatment is the hemicellulose content (%w/w) of dry biomass [13, 20–22].

#### **2.3 Lignin**

About 3 mL of 72% H2SO4 was added to 0.3 g of dried extractive-free samples. The mixture was kept at room temperature for 2 h while carefully shaking at intervals of 30 minutes to allow for initial hydrolysis. The second step of hydrolysis was carried out by adding 84 mL of distilled water and the resulting mixture was placed in an autoclave for 1 h at 121°C. The slurry was then cooled at room temperature. Hydrolysates were filtered through a vacuum using a filtering crucible. The residue is dried at 105°C and then incinerated in a muffle furnace at 575°C. The lignin content

was calculated as the summation of acid-insoluble lignin (AIL) and acid-soluble lignin (ASL). The acid-soluble lignin was quantified by UV-visible spectroscopy at 320 nm, and the acid-insoluble lignin was determined by gravimetric analysis [23].

$$\text{Lignin} = ASL + AIL \tag{1}$$
