(337s) From Waste to Value: Upgrading Food Waste to High Commercial Value Chemicals

Food waste (FW) poses a significant global challenge, with a staggering one-third of food production, approximately 1.3 billion tons, going to waste. Conventional FW treatment methods like landfill disposal and composting are environmentally detrimental. Addressing this challenge necessitates the exploration of alternative methods that selectively exploit the diverse composition of FW. One economically lucrative avenue is the extraction of bioactive chemicals (flavonoids, phenolic acids, etc.) with antioxidant and antimicrobial properties from FW feedstocks. This study addresses three key challenges in extracting bioactive compounds from food waste (FW), applicable to non-food biomass.

First, the choice of solvent is a critical parameter that affects the extraction efficiency. However, there is an insufficient fundamental understanding of the solvent selection process for FW extraction applications, with ethanol and methanol being common choices. A vital consideration is their safety for human consumption due to the application of target extractives in the pharmaceutical, cosmetic, and food industries, Thus, we develop a blueprint for solvent selection revealing more than 150 solvents providing higher solubilities than ethanol and methanol, propose the replacement of high-performing but toxic solvents with high-solubility green solvent mixtures and demonstrate the approach to real FW.¹

Second, microwave-assisted extraction (MAE) is a versatile and selective approach that offers high yields and employs less time, solvent, and energy making it environmentally and economically advantageous compared to traditional methods. However, most studies consider only pure single feedstocks and utilize an experimental design-based standardized approach inapplicable to complex feedstocks. Herein, we characterize the composition, physical and dielectric properties of different FW feedstocks to understand their dielectric behavior and influence on extraction efficiency. We provide insights into extraction from diverse feedstocks harnessing the untapped potential of mixed FW for extraction.²

Third, the downstream separation of the extracted phenolics from FW and non-food biomass is difficult owing to their similar chemical nature, high boiling points, and low concentrations in complex mixtures. The purification of natural phenolics is desirable to replace toxic synthetic antioxidants. We propose the use of bio-based molecular imprinted polymers to separate target phenolics. We employ computational methods to optimize the stability of monomer-template complexes and evaluate the polymer performance in various extraction solvents. Our approach, validated using coffee and potato peel waste extracts, outperforms traditional industrial purification techniques, delivering substantial economic value and carbon emissions reduction.³

References

1. Gupta, Y., Bhattacharyya, S., & Vlachos, D. G. Extraction of valuable chemicals from food waste via computational solvent screening and experiments. Separation and Purification Technology, 2023
2. Gupta, Y., Barrett, B., Vlachos, D. G., Microwave-Assisted Extraction of Value-Added Chemicals from Complex Food Waste Feedstocks. (Under Preparation)
3. Gupta, Y., Beckett, L. E., Sadula, S., Vargheese, V., Korley, L. T., Vlachos, D. G., Bio-based Molecular Imprinted Polymers for Separation and Purification of Valued-Added Chemicals from Food Waste. (Under Review, Special Issue, Separation and Purification Technology)