Fruit Waste As a Feedstock for the Development of ‘Safer’ Surfactants

Over the last decade, there has been tremendous interest in the use of `safer' surfactants, particularly in the household cleaning sector. Although the surfactant industry uses the term ‘natural surfactant’ to indicate the presence of bio-based ingredients in their product lines, the industry as a whole still heavily relies on petrochemical feed stocks and harsh chemical synthesis for the manufacturing of surfactants. In addition, after use, most commercially available surfactants are either non-biodegradable or degrade to produce more toxic products as in the case of Nonylphenol ethoxylates (NPEs). NPEs in particular pose a major environmental threat due to their degradation products being toxic endocrine disruptors. These surfactants can be persistent in the environment and can bio-accumulate in aquatic species. Therefore, there is a need for developing non-toxic, bio-based, and biodegradable surfactants using ‘safer’ materials and methods.

In an attempt to promote the use of renewable feedstock and eliminate the use of toxic materials in common household products, we have demonstrated the possibility of converting abundantly available polysaccharides (i.e. pectin and pectic acid) derived from fruit waste into efficient non-toxic and biodegradable surfactants. Polysaccharides are chemically modified using safe methods to achieve surface-active properties. These transformations are accomplished very efficiently in a microwave reactor, resulting in improved product yields and significantly shorter reaction times. To establish the safety of these polysaccharide-based surfactants, detailed cytotoxicity evaluation using human dermal fibroblast (HDF) and human leukemic (HL-60) cell lines have also been carried out. Surface and interfacial properties of these surfactants will be presented. Lastly, the potential for utilization of this new class of surfactants in detergent applications will also be presented. This research establishes the development of safer surfactants from renewable feedstock using ‘greener’ microwave-assisted synthetic routes, opening new possibilities for the synthesis of more sustainable amphiphilic polymers.