Chromatographers Find Value in Food Waste

The disposal of food waste can pose serious environmental problems. Food scraps from the kitchen often end up in landfill, where it rots and produces methane, a greenhouse gas.

A group of researchers from India have chemically characterized food waste using gas chromatography coupled to mass spectrometry (GC–MS) and GC with flame ionization detection (GC–FID) and identified possible reuse and disposal techniques (1). Food waste samples were collected from the kitchen of a girls’ hostel at the National Institute of Technology, in Rourkela, India. Food waste samples were collected, dried and the samples used for lipid extraction. A variety of different times and a variety of different solvent to food waste volumes were performed to analyze the lipid profile of the food waste samples.

GC–MS and GC–FID were performed to identify and quantify the presence of organic compounds in lipids from food waste. Caproic acid (6:1), lauric acid (12:0), mystric acid (14:0), palmitic acid (16:0), stearic acid (17:0), and oleic acid (18:0) were identified using GC–MS. Palmitic acid (60.89 mg/L), stearic acid (74.11 mg/L), and oleic acid (3.81 mg/L) dominated the lipid profile.

The team concluded that kitchen food waste could potentially be raw material for biodiesel production, as an alternative to fossil diesel. In addition, calcium (20.36 mg/L), iron (30.84 mg/L), magnesium (3.00 mg/L), and chromium (1.28 mg/L) were also identified. These metals could possibly be extracted and used in the pharmaceutical and agricultural industries, according to the researchers. - K.M.

Reference

• Sipra Barik and Kakoli Karar Paul, Journal of Environmental Chemical Engineering 5(1), 196–204 (2017).