Converting waste streams into revenue streams

Reduce. Reuse. Recycle.

For decades, an expanding global population and its growing dependence on durable goods, packaging and other consumer-related materials have made these three words a rallying cry — as well as an effective action plan — for addressing ever larger and more unmanageable amounts of waste.

But when it comes to dealing with food waste, the picture is more complicated. ‘Reduce’ remains a fundamental strategy, one that’s making great strides in addressing food waste around the world. But what about reuse and recycle? When the waste you’re dealing with is non-durable organic matter, things get trickier.

Agilent Technologies, a recognised world leader in analytical solutions across multiple disciplines, has teamed up with Professor Vincent Bulone at the University of Adelaide and partners at the Research Consortium for Agricultural Product Development (RC-APD) to look at ways to introduce a fourth ‘R’ into the mix: Reimagine.

Partners in discovery

Through the recently established analytical platform Adelaide Glycomics, these groups are working together to turn a creative eye toward a specific type of waste — agricultural waste — by asking a fundamental question: Are there valuable substances within that waste that are just waiting to be identified, extracted and put to good use?

Photograph of Dr Tom Hennessy (Academia & Collaborations Manager for Australia, Agilent Technologies (left)), Prof. Vincent Bulone (centre) and Prof. David Bradley (right) at the launch of Adelaide Glycomics in 2016.

Agricultural waste is an enormous problem, one that impacts our society on multiple levels. The volumes of agricultural waste continue to increase, largely because of the stringent criteria imposed by retailers for produce appearance (in addition to the impact of environmental factors) — even while malnutrition remains a serious problem in our society.¹ However, the magnitude of the problem is mirrored by the magnitude of the opportunity; such a huge amount of waste material stands poised as an exploitable resource of industry-altering proportions.

Modern analytical and discovery technologies are ideal for tapping into the potential of that resource. Using similar approaches to those employed to identify genes that promote cell differentiation toward plant seed development, the Adelaide Glycomics-led team seeks to identify genes and characterise the metabolic pathways involved in the biosynthesis of bioactive compounds from various crops.

A number of these compounds are known, but many are largely commercially available only as synthetic alternatives. Other compounds with potentially unique properties no doubt await discovery and characterisation. The knowledge gained through these efforts will be exploited for the conversion of agricultural waste into products with significant added value, opening up new revenue streams for farmers and others in the food/agriculture sphere.

Central to this project is the industry PhD (iPhD) project, established by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) of Australia with the goal of extending high-calibre PhD candidates the opportunity to deliver real-world solutions across industry, applied research and academia for the benefit of society.² Through Adelaide Glycomics, Agilent Technologies provides an iPhD student with access to technology and other financial and in-kind support, including analytical instruments and training that are fundamental to the effort.

From Agilent’s perspective, this is a ‘multiple-win’ opportunity. There are so many positives that can come out of partnerships such as this, even beyond the stated goal of addressing the very pressing issue of waste. More broadly, it’s a great chance to support the food and agriculture industries as they tackle problems that are central to their continued viability. At the same time, Agilent is able to contribute in the development of the next generation of scientists, and if successful, help nudge the needle of sustainability into a better place.

Essential guidance for these efforts comes from Professor Vincent Bulone, Director of Adelaide Glycomics and professor at the University of Adelaide School of Agriculture, Food and Wine. Through Adelaide Glycomics in particular, Professor Bulone is uniquely positioned to oversee the convergence of the strengths of the various partners toward addressing the multifaceted issue of agricultural food waste. “Our projects largely aim to exploit scientific knowledge and discovery to benefit the growers associated with our Research Centre,” said Professor Bulone. “We use our knowledge to find practical solutions for the management of agricultural waste and the conversion of biomass into products with a higher value; in other words, we use science to turn waste into profit, and solve issues that are unsustainable in modern agriculture. Key products of interest include bioactives with antioxidant properties, which find use in skincare products. We are also looking at carbohydrate polymers to produce high-strength composite materials to replace petroleum-derived plastics, as well as a number of food supplements with health-promoting activities.”

Potential targets, potential gains

Early work has focused on exploring the potential for extracting high-value compounds, including colouring and flavouring agents and novel complex glycans, from apples and cherries, both of which are easily damaged and have potentially short shelf life. Presently, much of the waste from these crops is returned to the earth — composted, buried or simply left to rot where it falls — with none of the costs invested in their production having been recouped as revenue.

However, flavonoids present in cherries, apples and other crops could prove to be extremely valuable, with commercially available synthetic versions sometimes costing many thousands of dollars (USD) per gram.³ Known compounds such as this represent ‘low-hanging fruit’ as targets for extraction and commercialisation. Other possible targets, including a number of carbohydrate polymers, await further characterisation of their properties and modification for optimisation toward specific applications. Still other targets no doubt await discovery.

Another example of potential value involves starch from (for example) downgraded potatoes, which can be used for the production of bioplastics and functional foods with health benefits, by exploiting the properties of the so-called resistant starches.⁴ These resources also offer utility in the creation of functional materials, following derivatisation of the starch polymers. In addition, proteins from potatoes and polyphenolic compounds with biological activity, such as antioxidant or antimicrobial activity, are present and can be recovered.^5,6

However, doing so economically requires careful thinking, as some of these compounds are naturally present in low abundance. Still, these efforts remain driven by the goal of using as close to 100% of the waste as possible, by generating a range of products derived from multiple individual components that are sequentially extracted. In this way, profit can be made both from major compounds such as starch, and from less abundant but highly valuable bioactives such as polyphenols.

A new alchemy for a new challenge

Unlike the alchemy of old, there’s no Philosopher’s Stone that can magically transform these waste products into revenue-generating materials. Accomplishing this feat takes the right mix of perseverance, strong science and cutting-edge tools.

As a researcher on the front line of this quest, iPhD candidate Daniel James Clayton-Cuch finds the work isn’t short of challenges — or satisfaction. “Agricultural waste is an important problem in Australia, but of course, it isn’t a uniquely Australian issue. And while Australia’s geography adds its own layer of complexity, and perhaps a different sort of urgency, it’s rewarding to think the work we’re doing here might become an important part of much larger efforts.”

As for the work itself, Clayton-Cuch added, “It’s really a unique opportunity to be part of a program that has such broad support from leaders in so many areas. Being the beneficiary of this confluence of expertise, experience and technology is really an ideal environment for growing as a scientist.”

Adelaide Glycomics laboratory with high-end LC/MS systems.

At Adelaide Glycomics, PhD students like Daniel Clayton-Cuch and other young researchers are encouraged to focus their efforts on three essential facets of the agricultural waste issue: the development of new technology in collaboration with Agilent Technologies, the discovery of new bioactive and structural compounds with potential applications relevant to a multitude of sectors, and the thorough assessment of the properties of natural compounds and their derivatives.

These activities are more essential today than ever before. Converting waste into gold while developing new green technologies and products addresses a fundamental issue facing modern society. The process also helps ensure that future R&D leaders are trained to bring new ideas and innovation to sectors that are predicted to continue to grow.

^{[1] https://www.theguardian.com/environment/2017/oct/13/you-say-tomato-retailers-say-waste-research-finds-produce-problem}

^{[2] https://www.csiro.au/en/Careers/Studentships/Industry-PhD}

^{[3] https://www.scbt.com/browse/chemicals-Other-Chemicals-flavonoids/_/N-vxw660}

^{[4] Tsang Y.F et al. Production of bioplastic through food waste valorization. Environmental International. 2019; 127: 625-644. https://doi.org/10.1016/j.envint.2019.03.076}

^{[5] Kowalczewski PŁ, Olejnik A, Białas W, et al. The Nutritional Value and Biological Activity of Concentrated Protein Fraction of Potato Juice. Nutrients. 2019; 11: 1523. doi:10.3390/nu11071523}

^{[6] Fereidoon S and Priyatharini A. Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects – A review. Journal of Functional Foods. 2015; 18: 820-897. https://doi.org/10.1016/j.jff.2015.06.018}

Image credit: ©stock.adobe.com/au/yolya_ilyasova