The safety, sustainability, and profitability of the food industry will remain a key societal challenge in the decades ahead. For example, the value of food waste in Canada is currently over $31 billion annually (or about 2% of Canada’s GDP), and when the cost of associated wastes (e.g. energy, water, etc.) is factored in rises to over $100 billion. In North America, over 20% of the initial production of meat is lost due to waste, most of which occurs at the later stages in the food supply chain. The carbon footprint associated with global food waste is estimated to be over 4.4 GtCO2 eq per year with over 20% of this coming from meat waste. Smart materials and devices that are capable of sensing meat spoilage in its early stages will be needed in the decades ahead to ensure safe meat consumption and minimize waste, both at the end consumer level and earlier in the production chain. When meat begins to degrade, the protein decomposes and releases biogenic amines (e.g. cadaverine, H2N-(CH2)5-NH2). Early detection of these volatile amines therefore provides a means to sense the onset of meat spoilage and can potentially lead to a significant reduction in meat waste. Optical sensors that work on, for example, the change in plasmonic properties of a material when volatile amines are present can be envisioned as being integrated into meat packaging to alert the consumer to potential spoilage issues. Hand-held devices that can detect volatile amines via a change in electrical resistance can also be envisioned as being useful by meat inspectors further up the supply chain. In this work, ZnO nanorod films are fabricated on interdigitated electrode substrates and decorated with sensitizing catalyst particles. The materials are characterized physico-chemically for their morphology and composition. A chemiresistive response to volatile biogenic amines is tested for by utilizing the model test gas methyl amine (CH3-NH2), which is more convenient to work with in the gas phase for the initial screening experiments than volatile biogenic amines. An excellent chemiresistive response to amines is found. The effects of gas concentration, temperature, and catalyst are currently being investigated, as is the role of oxygen on the sensing mechanism. In parallel with the chemiresistor work, optical sensing is also being explored utilizing colloidal Ag and Au nanoparticles synthesized through a common citrate reduction. The colloidal sols are incubated with methyl amine or cadaverine aqueous solutions. The surface enhanced Raman spectra (SERS) of both amines is monitored to determine the presence of the molecules. SERS is an ideal technique for sensing biogenic amines as the primary amine interacts strongly with the Ag and Au surfaces resulting in strong SERS spectra. The effect of surface chemistry and solution pH on the limits of detection are currently being investigated.
Journal: TechConnect Briefs
Volume: 3, Biotech, Biomaterials and Biomedical: TechConnect Briefs 2018
Published: May 13, 2018
Pages: 12 - 15
Industry sectors: Advanced Materials & Manufacturing | Personal & Home Care, Food & Agriculture
Topic: Personal & Home Care, Food & Agriculture