Extraction and Characterization of Cellulose Microfibers from Agricultural Wastes of Onion and Garlic

As a new lingo-cellulosic natural fiber sources, agricultural processing wastes of onion and garlic, stalks and skins, were investigated by determining their chemical composition and characterization of their cellulose microfibers extracted by chlorite and alkaline extraction method. The extracted cellulose microfibers were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscope (SEM). The stalks and skins of garlic and onion were composed of cellulose (41–50%), hemicelluloses (16–26%), and lignin (26–39%), which indicates that the predominant polysaccharide in the stalks and skins of onion and garlic is cellulose. The cellulose microfibers extracted from the stalks and skins of onion and garlic were more heat stable than their neat fibers. The result showed that the skin and stalk of onion and garlic have a high potential for the utilization as a new source of biopolymer resources.