Sustainability has become a top-of-mind issue for consumers, reaching all industries and demanding solutions to address challenges related to a human population set to reach 10 billion by 2050 (United Nations). Within the food industry, implementing strategies for reducing loss and waste is of paramount concern in emerging and developed markets alike. Food “loss” represents losses occurring during the manufacturing and processing stages of the supply chain, while food “waste” occurs at the retail, distribution and consumer levels. More than one-third of all food produced ends up in either the loss or waste category, costing the global economy an estimated $940 billion annually and contributing 8 to 10 percent of global greenhouse gas emissions (FAO). For perspective, recapturing this lost and wasted food could provide enough sustenance to feed two billion people—three times more than the planet’s current undernourished population (FAO).

Food spoilage is a natural process, of course: Food gradually loses edibility via color, taste, texture or nutritional degradation. Food preservation can be defined as the treatment of foods with ingredients and/or processing to halt or slow microbial growth and/or chemical degradation while prolonging a food’s quality and nutrition. Preservation effectively extends shelf life by increasing food viability. Many of the foods and beverages we enjoy today are possible because of modern (as well as ancient) preservation techniques—including acidification, fermentation, drying, salting, smoking, thermal processing and refrigeration, among others—that work to alter intrinsic and extrinsic food attributes with an eye to better shelf life. Intrinsic (e.g., pH; salt; moisture; competing microflora) and extrinsic (e.g., storage time and temperature; modified atmosphere packaging) factors are dictated primarily by food type and preservation method used and contribute to varying extents to the microbial safety and shelf life of a vast range of different foods.

Without safety hurdles in place, pathogenic bacteria, such as Listeria monocytogenes and Clostridium botulinum can contaminate food. When consumed by humans, these bacteria can make us critically ill. Less harmful bacteria, molds and yeasts can also grow in (or on) foods, rendering them inedible. Other factors that degrade food quality and can lead to waste: oxidation and enzymatic breakdown. Oxidation impacts food safety, quality and flavor by causing an undesirable chemical change that can turn fats rancid, and cause vegetables and fruits, e.g., cut potatoes and apples, to turn brown. Enzymes and other chemical breakdown processes are responsible for transforming foods into an unpalatable—and at times unsafe—product.

Meat and bakery products represent the highest value and volume, respectively, in the food-waste equation globally. Shelf-life extension of these and other popular perishable and semi-perishable foods (e.g., dairy products, plant-based meats and beverages) is a critical approach that can meaningfully impact food longevity. In fact, researchers have found that approximately one-half of consumer food waste could be prevented or reduced by increasing the shelf life of retail food items. But why only half? Mainly, this is because consumer behavior plays just as important a role as shelf life in determining whether a product is consumed or goes to waste once it arrives in the consumer’s home.

Let’s focus on ingredients and how these can be used in combination with formulation and/or processing/environmental hurdles to keep food safe and extend its nutritional reach—in short, allowing it to feed more people rather than go to waste.

Decreasing Meat Waste

Meat is the category that is forefront for consumers in terms of food safety concerns; it also represents the highest value of food wasted each year. The USDA (U.S. Department of Agriculture) has strict legislation to ensure ready-to-eat meat processors prove L. monocytogenes inhibition to protect consumers in the event of product contamination. Several common ingredients are used for food safety and shelf-life extension in meat:

Conventional:

• Solutions based on the salts of organic acids, e.g., lactic acid and acetic acid.

• Nitrite-based solutions for cured meats.

Clean-label:

• Buffered vinegar-based solutions, a natural source of acetic acid.

• Starter and bioprotective cultures that can be used in fermented meats, such as pepperoni; these create the end product and maintain its shelf life via in situ lactic acid formation.

• Fermentation metabolites, natural sources of organic acids, peptides or nitrite, e.g., cultured dextrose or cultured celery, that can be used in deli meats.

In plant-based meat, producers are experiencing challenges around spoilage—quality issues, product going to waste prematurely, or goods with a very short (therefore infeasible) shelf life. Formulations to extend the shelf life of both meat and plant-based meat substitutes are best created holistically. That is, controlling pathogens is of little value if outweighed by spoilage, bad taste/texture, and poor relative appeal of a product at the end versus the start of a product’s life. Considering these issues as a whole is the most efficacious approach.

Furthermore, we are seeing optimal impacts from preservation systems that leverage ingredients with multiple “modes of action,” i.e., that are synergistic in nature. In these cases, lower doses of each ingredient can be used to achieve shelf-life goals, affecting taste minimally versus a higher-dose, single-ingredient solution. Strategies include leveraging two unique organic acids, or one organic acid in combination with a peptide or salt.

When these systems are used to replace processing preservation methods—or in addition to them—there is the added benefit of secondary shelf life (post-opening). This is particularly valuable in foodservice, for which pack sizes are large and foot traffic patterns may shift during atypical times (as in during the COVID-19 pandemic, for instance).

Consider the cost: Each kilogram of meat produced that goes to waste contributes an average equivalent environmental cost of 60 kilos of CO2 and more than 1,400 liters of water—and this does not include the further greenhouse gas emissions from wasted meat as it breaks down (Our World in Data)! Not only is this the highest consumer/industry value category of food waste each year, each kilo of waste comes at the highest possible environmental cost. (Nature Food).

Reducing Bakery Waste

Bakery is the highest-volume category of food waste worldwide (RTS). While not an immediate concern for food safety, most consumers will be familiar with the day-to-day experience of having bread go moldy or become stale before it can be eaten. (As an aside, there are many desserts and some newer brewery products originating from upcycling stale bread)!

Moldy bread is a quality or spoilage issue, and the most common solutions for it tend to be propionic acid-based given that range’s high efficacy for common bread pH values. Other emerging solutions are acetic acid-based—more common in rye and German breads that are seeking an acidic taste, or in breads whose yeast activity is too low when using propionates.

Adding preservation to bread increases the shelf life on average by 50 percent—and in some cases up to 75 percent—and offers a great opportunity to prevent bread waste completely at the retail and consumer levels. And this is a worthy goal: Each loaf of wasted bread contributes an average of a half a kilo of CO2 and more than 500 liters of water (New Scientist). In fact, there are parts of the world in which bread is still baked in the home or store daily, with anything not consumed going to landfill. Kerry experts estimate that more than 12 billion loaves of bread being wasted annually. This is a great opportunity to prevent waste and feed more people with our planet’s resources.

Depending on the bread pH, cost and shelf-life goals of an industrial baker, there are a variety of established solutions available that leverage both conventional and clean-label ingredients:

Conventional:

• Propionic acid-based solutions, e.g., calcium and sodium propionate.

• Acetic acid-based solutions, e.g., calcium and sodium acetate or diacetate.

Clean label:

• Bacterial fermentates: These are a natural source of organic acids, e.g., fermented wheat, brown rice (for gluten free breads), or sugar. They perform best in baked goods with a pH of ≤5.4.

• Buffered vinegar, particularly calcium buffered vinegar, has shown positive sensory results and shelf-life extension in bread with a pH of ≤5.2.

Bread shelf life is highly influenced by pH level, so the use of acidulants can complement any of the above solutions by decreasing the pH to make more undissociated acid available in the product.

Globally, consumer priorities vary based on location and stage of life. For some, taste is king, while others are focused on safety and affordability; still others seek out what the industry has coined “clean-label products,” i.e., focused on nutrition, familiar ingredients, and/or sustainability goals. Within these priorities, all consumers want safe food that reaches them in good quality—and doesn’t go to waste.

Conclusion: Act Now to Reduce Food Waste and Loss

Depending on the preservative and food application, adding preservative ingredients represents a multi-functional component of the food safety and quality process through microbial (e.g., spoilage and pathogen) and oxidation (e.g., enzymatic browning or fat rancidity) inhibition. The solution, quite simply, requires using either conventional or clean-label preservatives—bacterial fermentates, protective cultures, vinegar, citrus extracts or smoke—to decrease food waste and loss.

By using preservation ingredients and processes responsibly, we can reduce food waste, increase food shelf life, and help feed the planet with safe and high-quality foods. Each producer brings their own specific preservation challenges—that may include the dynamics of a unique supply chain, geographic and/or consumer preferences, or cost and shelf-life targets—but, whatever the need, an experienced preservation partner is invaluable. Able to draw from the full breadth of available industry solutions, these experts provide the in-depth knowledge needed to protect and perfect products while achieving longer and better shelf-life outcomes.

Clearly, whether to protect a product’s shelf life using clean-label or conventional preservation techniques, or a combination of both, is an open choice for all food manufacturers to consider. On the other hand, the urgent need to reduce food loss and waste globally is not open to debate: It demands action at all levels of the food supply chain—and there is not a minute to waste.

Resources:

www.un.org/development/desa/en/news/population/world-population-prospects-2019.html.

www.fao.org/food-loss-and-food-waste/flw-data).

www.fao.org/news/story/en/item/203149/icode/.

https://ourworldindata.org/food-choice-vs-eating-local.

www.nature.com/articles/s43016-021-00358-x.

www.newscientist.com/article/2122857-a-loaf-of-bread-emits-half-a-kilo-of-co2-mainly-from-fertiliser/.

Sarah Engstrom is a RD&A manager for Food Protection & Preservation at Kerry, where she works to develop and apply cutting edge technologies for improving shelf-life and safety of foods using clean label and conventional preservation ingredients. She holds M.S. and Ph.D. degrees in food science from the University of Wisconsin. Prior to her time at Kerry, Engstrom worked as a research microbiologist for the Food Research Institute and a corporate microbiologist for Oscar Mayer and Land O’Lakes.