**2.4 Cellulose**

The cellulose content (%w/w) was calculated by difference.

## **2.5 Fourier transform infrared (FT-IR) spectroscopy**

Nicolet IS 5 Thermo Fisher Scientific, USA FTIR spectrophotometer was used to analyze the surface chemistry of the agricultural waste samples. The dried waste samples were analyzed by scanning between wavelengths 400 and 4000 cm–1. The distinctive functional groups on the surface of the melon seed shell, moringa seed pod, and mango seed endocarp can be observed from the samples' FTIR spectra.
