Extraction and Characterization of Proteins from Castor Oil Meal for Medical Applications

Proteins from castor meal have been turned into films with desired mechanical properties, water sorption, and properties suitable for medical and other applications. With more than 800 000 tons of castor meal generated globally every year, there is great scope for utilization of the meal and the proteins in the meal for various applications. However, castor meal contains toxic compound ricin which makes the meal unsuitable as food or feed. Castor meal contains up to 40% proteins which have not yet been studied for their properties or potential applications. In this research, proteins in the meal have been extracted using simple alkali treatment, and characterized for their structure and properties. Films developed from the proteins have been tested for their mechanical, thermal, antibacterial activities, and water resistance properties. Since the protein films have considerably low mechanical properties and are unstable in aqueous conditions, they have been crosslinked with citric acid which is known to be green and biocompatible crosslinker. Films with a maximum strength of 2.1 MPa, considerably lower water sorption (200%), and up to 98% free radical scavenging activity were obtained. L929 cells cultured in extracts from the protein films showed no cytotoxicity and had better viability compared to DMEM suggesting the appropriateness of the films for tissue engineering and other medical applications.