Patricia Cazón: «Biotechnology is presented as an excellent tool for revalorising waste and obtaining products with high added value»

Every year, 8 million tons of plastic waste are in the sea. According to the UN, if this figure is maintained, by 2050, there will be more plastic than fish in the oceans. Apart from being a frightening headline, this fact highlights the need to tackle this global problem from new perspectives, in which R&D plays a critical role.

Research on sustainability, environmental responsibility and resource use shines the most in cases like this. People like Patricia Cazón Díaz perfectly represent this necessary professional approach.

With a PhD from USC and as a postdoctoral researcher in the Food Technology Area of Campus Terra, Patricia Cazón focuses her work, among other things, on the use of by-products and waste to manufacture biodegradable packaging. Her research findings emphasise the importance of nurturing a real circular economy to achieve sustainable growth. 

Reversing the trend of massive consumption of plastic elements and reducing their global pollution rate is a challenge that demands different solutions. Still, today, we focus on one area in which we predict a promising future.

-You have worked on a project on the food packaging properties of grape bagasse. What are the conclusions of this research?

-Among our lines of research is the revalorisation of by-products or wastes from the agri-food industry. We are studying revalorisation strategies that use these by-products as a source of nutrients for biotechnological applications. For example, we studied the viability of these wastes as low-cost culture media for the production of bacterial cellulose. In addition, we analysed these wastes as a source of bioactive compounds, paying special attention to compounds with antioxidant capacity to develop additives of natural origin for the food industry.

In this work, we use grape bagasse as a source of nutrients for producing bacterial cellulose and as a source of antioxidant compounds to develop active biomaterials. We observed how the antioxidant compounds from the bagasse extract interacted with the cellulose fibres during the polymer synthesis process, directly obtaining a biodegradable material with high antioxidant capacity. We have tested this cellulose with antioxidant activity as a material for use in direct contact with food or food packaging; for example, as a material for packaging foods such as cheese that have high-fat content and are susceptible to rancidity, obtaining excellent results. Although we have only studied this material as food packaging so far, it may also be particularly interesting for applications in other areas such as biomedicine or the cosmetics industry. 

This study has opened the doors to a new approach to revalorising agri-food waste and simultaneously producing bacterial cellulose with improved biofunctional properties.

-In the same line, you have also developed an environmentally friendly slice separator from chitosan, a by-product of the fishing industry, enriched with nettle extract. From a distance, it seems a very relevant contribution to avoid, for example, the use of plastics, which is so widespread in food packaging. Is that so?

-Chitosan is a biomaterial of great interest and extensively studied, mainly because it is biodegradable, comes from fishing industry waste (crustacean exoskeleton), has antimicrobial properties and is easy to use compared to other biopolymers. For example, by taking advantage of the solubility properties of chitosan (soluble at slightly acidic pH), it is possible to obtain a polymeric solution that can be enriched with different additives, such as essential oils or other natural extracts, to improve the properties of the final material. An example was this work, which is part of the doctoral thesis recently defended by María Flórez Mora and which I have directed. In this work, we investigated strategies to confer antioxidant capacity to chitosan films using wild plants that lack commercial interest and are widely distributed worldwide, such as nettle. We observed that using simple and environmentally friendly extraction methods makes it possible to obtain an extract with high antioxidant capacity that can be directly combined with chitosan. The developed films were studied for cheese packaging, observing excellent results, both in terms of the ability to extend the food's shelf life and the material's resistance throughout the storage process. This study demonstrated the feasibility of producing a biodegradable biomaterial from waste and plants of low commercial interest that can be used in the food industry. 

-You have developed another cheese slice separator with chitosan and an algae extract. Will it be on the market in the short or medium term?

-I could not say if exactly this development will be seen in the short-medium term in the market, but indeed, similar products or with the same base, since resources are being allocated to innovate in this type of materials and to be able to scale up their production to an industrial level. The trend in the market will be to displace, as far as possible, non-biodegradable materials with materials of natural origin and with less environmental impact, whether this change is driven voluntarily by companies or motivated by stricter regulations. Companies know this and are interested in new, more natural, sustainable alternatives. For example, as a result of our recent work on developing biomaterials enriched with natural extracts, we are currently carrying out two projects in collaboration with two companies: a cheese factory and another company dedicated to reusing agricultural waste to manufacture coatings for butter packaging. Both companies have shown interest in these innovations and are evaluating their feasibility.

On the other hand, Campus Terra is promoting research into new active biomaterials in line with the priorities established by the Horizon Europe 2021 - 2027 program and the RIS3 21-27 challenges of Galicia. In this sense, we have obtained funding for the BIOPACK-A2 project through the Campus Terra 2024 Call for Collaborative Projects. In this project, four Campus Terra research groups from different areas (Food Technology, Inorganic, Pharmaceutical Technology and Biochemistry) collaborate to develop cellulose-based biomaterials with catalytic synthetic antioxidants. This project will significantly interest the food industry and the pharmaceutical sector.

We also have funding for the European call project Seafoodture, with Dr Patricia López Sánchez as principal investigator. In this project, we are working with 11 other partners, including companies and research centres from all over Europe, to valorise algae as a source of sustainable ingredients and biomaterials.  
 

-Bacterial cellulose and gluconic acid from grape bagasse and potato waste. Your research is an excellent example of all that the circular economy can bring to a world that needs to move steadily forward in sustainability. Do you agree with this assessment?

-Yes, of course. There is a clear need to change the traditional linear economic model, where resources are exploited to manufacture a final product, generating uncontrolled waste, to a circular economy model, aiming to optimise resources, minimising waste and environmental impact. This need is already reflected in the initiatives of the European Commission, which has established the circular economy as a fundamental pillar to achieving sustainable growth and greater competitiveness in Europe, taking legislative measures in favour of this economic model and promoting research and innovation. 

In this sense, biotechnology is presented as an excellent tool for revaluing waste and obtaining products with high added value. For example, in our case, we use bagasse and potato waste as a low-cost culture medium for manufacturing biomaterials such as bacterial cellulose and additives with high commercial value, such as gluconic acid. In addition, this strategy can provide an economic opportunity and generate new business for agricultural companies by transforming waste into marketable products.

-In 2022 and 2023, you were included in Stanford University's ranking of the most cited researchers. What does this mention mean to you?

-Honestly, it was a surprise that I was very happy to receive. I would never have imagined that I would appear on this list. This news has been a great stimulus to continue advancing in my projects with enthusiasm since a research career is not easy and is full of moments of complete uncertainty.

-The use of plastics globally is unsustainable. Work like yours is a very significant contribution to reversing this trend. Will we see any substantial changes in the short term in one of these global challenges?

-We have already been observing significant changes for less than a decade. For example, today, it is no longer possible to buy single-use plastic cups, utensils, or straws, or it is already common in supermarkets to see people using their reusable bags. New regulations, as usual, have driven these changes, as we have seen in other areas. This is likely the start of a significant transformation. Initially, these changes focus on managing plastics and adopting measures to reduce their use and promote recycling and reuse. However, there is already a demand from the European Union to encourage research and development of biodegradable and renewably sourced alternatives to replace, to the greatest extent possible, synthetic plastics. A total substitution of plastic materials is impossible and probably won't be in the short term. However, promoting and raising awareness of their responsible use is necessary.

On the other hand, society is becoming increasingly aware of the negative environmental impact of the uncontrolled management of plastic waste and the harmful effects on human health that can be caused by the microplastics derived from this waste. This change in society's mentality will drive the demand for new sustainable alternatives, which will trigger more significant innovation by companies in food packaging.

-You work at the National Research Center for Agricultural and Veterinary Sciences INIAV in Portugal. What does your work consist of?

-At the INIAV center, my research focuses on exploring new polymeric matrices, such as whey, and evaluating citrus and tea residues for the extraction of potent antioxidant and antimicrobial agents. This experience is enormously enriching and productive thanks to the available resources and the team of INIAV researchers with a broad and solid background.

In addition, access to advanced equipment, such as UHPLC MS/MS and UHPLC-ToF-MS, has allowed me to determine and quantify phenolic compounds from natural extracts. Until now, I had not had the opportunity to carry out this type of study, which is helping me advance and expand my lines of work.

INIAV has a food safety unit formed by highly collaborative researchers with extensive experience. Together, we are evaluating the antimicrobial effect of the developed materials against pathogens such as Pseudomonas, Salmonella, and E. Coli, among others. This comprehensive analysis allows us to assess the safety and efficacy of these materials as food packaging and other possible applications. 

On the other hand, I have had the opportunity to explore lines of research that are utterly different from my previous experience but equally related to food safety and that have been tremendously enriching, such as the detection and quantification of pesticides in food. I am working on an exciting project that evaluates the effect of precooking and cooking treatments on reducing more than 100 pesticide residues in different rice varieties.

-Slovenia, Mexico, United States, Poland... You have done a lot of training stays. What do you take from these experiences?

-These experiences have significantly impacted my professional and personal development. On a professional level, it is evident that working with different research groups, with different organisational methods, new lines of research, and also teams formed by experts with a high level of knowledge in my field of study has helped me to experience, on many occasions, an accelerated pace of learning that has been fundamental in my work. But the personal impact of all these experiences has been even more enriching and, in a way, has shaped my personality. Getting out of my comfort zone has been fundamental to strengthening my confidence and facing changes with determination, even if sometimes it is difficult. In addition, collaborating with people from cultures and personalities so different from mine has helped me to improve my ability to work in a team. With this, I want to avoid idealising or romanticising stays abroad since it is rarely easy, and in my case, there have been complicated moments. But taking an overall balance and looking back, I can say with total certainty that it has been worthwhile, and I would do it again.