In a novel valorization approach for simultaneous pectin extn. and pretreatment (SPEP) of citrus waste (CW) by dil. nitric acid and ethanol, almost all of the CW was converted to bio-derived chems. in a singlestep process at a low/moderate temp. The SPEP was performed at different temps. (70 °C and 80 °C), pH (1.8, 3.0, and 4.3), and extn. times (2 h and 3 h) with a full factorial design. The max. pectin yield of 45.5% was obtained at pH 1.8, 80 °C, and 2 h. The pectin yields at pH 1.8 were much higher than at pH 4.3 and 3. Also, the degree of methyl-esterification at pH 1.8 was higher than 50%, whereas at the higher pH, low methoxyl pectins were extd. The treated CW obtained after the SPEP, free from limonene, was subjected to sep. cellulolytic enzymic hydrolysis and ethanolic fermn. The glucose yields in the enzymic hydrolyzates were higher for the CW treated at pH 1.8. The fermn. of the enzymic hydrolyzates by Mucor indicus resulted in fungal biomass yields in the range of 355 to 687 mg per g of consumed sugars. The optimum conditions for obtaining the max. SPEP yield (glucose + pectin (g) / raw material (g)*100) were pH 1.8, 80 °C, and 2 h, which resulted in a yield of 58.7% (g/g CW). [on SciFinder(R)]