Extraction and Characterization of Microcrystalline Cellulose from Walnut, Almond and Apricot Stone Shells

Abstract

Walnut, Almond and Apricot stone shells are abundantly available agro wastes worldwide and are sources of cellulose. In this study microcrystalline cellulose were isolated from these renewable biomasses through acid hydrolysis method. Isolation of microcrystalline was performed due to its potential significance in cosmetics, medicine and food industries. Acid hydrolysis is carried out at different concentrations of sulphuric acid. Surface morphology and elemental composition of microcrystalline cellulose was characterized with Scanning electron microscopy, energy dispersive x-ray spectroscopy and FT-IR spectroscopy. SEM clearly showed that microcrystalline cellulose obtained through high acid concentration has better structural similarities with commercial microcrystalline cellulose However microcrystalline cellulose obtained with low concentration of acid showed lower fibrillation. Elemental analysis revealed that amount of Sulphur impurity (1.17-1.18) is present in microcrystalline cellulose when hydrolyzed with high H2SO4 concentration while negligible (0.10-0.72) in microcrystalline cellulose treated with low concentration of H2SO4. It is also found that carbon and oxygen contents range in Walnut, almond and Apricot C; 50.89-58.73, 54.07-55.58, 54.19-55.62, O; 39.72-48.01, 43.54-43.71 and 41.75-44.34 respectively while FT-IR shows required functional groups in prepared MCC specifically representing beta 1-4 glycosidic linkage at 849 cm-1 that depicts improved cellulose content with in the sample. Thus, this work confirms that Walnut, Almond and Apricot stone are promising sources for microcrystalline cellulose.