Download PDF Summer Bridge on Smart Agriculture June 15, 2022 Volume 52 Issue 2 People everywhere rely on agriculture in one form or another – for food, animal feed, fiber, and other necessities. The summer 2022 articles describe precision indoor farming and alternative protein food systems, advances in food processing, genome editing, digitalization, sustainable and regenerative agriculture, the role of a circular economy, and the important role of policy. Food Processing for Today and Tomorrow Tuesday, June 14, 2022 Author: Josip Simunovic and Kenneth R. Swartzel Engineering advances in food processing ensure food safety and quality while reducing energy and waste. Food product preservation has advanced rapidly over the past 75 years. Thermally processed shelf-stable food is available worldwide, and frozen foods with long shelf lives are available throughout most of the developed world. Microwaves have revolutionized home food preparation. But can food processing keep pace with global population growth? In this article we discuss several processing areas that will contribute to a sustainable food future for the planet. Introduction There are global, political, demographic, and cultural issues at play. As the world population grows to approach 10 billion by 2050 (Pew Research Center 2022), food waste and pollution—both of which occur in the -ransition from raw source to preservation and consumption—are critical challenges (-FoodPrint 2022). Moreover, the year 2010 saw the scale tip, with more people living in urban areas than rural, and there are now 26 “megacities” around the world, each with more than 10 million residents. By 2025 Tokyo is projected to have 39 million residents and New York is projected to grow 20 percent to 24 million. Getting high--quality food in sufficient quantities into these urban areas remains a major challenge (Knorr et al. 2018). The global demand for meat quadrupled from 71 million tons in 1961 to an estimated 284 million tons in 2007 (Bittman 2008). In developing countries, per capita meat consumption doubled between 1987 and 2007, and by 2050 it may well double again. In the United States in 2015, 22.4 percent of deaths among males and 20.7 percent among females were attributable to dietary factors (Benjamin et al. 2018). So there is a public health motivation for increasing the availability of healthy processed foods. Finally, in most industrialized nations the population is becoming greyer, and more men are reaching the ages that women traditionally dominated. This is relevant because men typically consume more calories and require more inputs because of their generally larger body mass. Changes in urban growth and an increase in the elderly population create challenges to food availability. Advanced technologies from multiple industries are being incorporated in the food industry to meet these challenges. Taking Stock Although cultured meats may reduce the need for live animal harvesting (Swartzel 2000), projected increased demand for animal protein in diets worldwide will require a strong live animal industry. With current technologies, meats can be rendered sterile, packaged in large aseptic containers (low-weight bag-in-box, or recycled packaging), and shipped worldwide unrefrigerated. And thanks to mature aseptic transfer technologies, foods can be stored for long periods of time and transported around the world in tanker loads without losing nutritional value or taste (Howard 2012). Energy, waste, and quality all benefit from the technologies involved in each step. Most large mass meal preparation operations (40,000 meals/day and more) involve sizable kitchens with raw food preparation. Meals that are not “made from scratch” are derived from ingredients in #10 cans (6 3/16" in diameter and 7" high) or reheated frozen products. The packaging of these products, especially cans, creates disposal and sanitation issues; advanced processing and well-developed aseptic packaging technologies may reduce such problems. The technology exists to process an enormous variety of products that are high in quality and shelf stable over long periods. These products are commercially sterile and do not need to be prepared in the kitchen. They run the gamut from thin to thick/viscous fluids, purees, pulps, small discrete particles to low- and high-load large discrete particles (soups and stews), sauces, pastas, and any combination. With the elimination of cross-contamination, commissaries, cafeterias, and mess halls can be assembly areas with dinners made to order. Meal items can be selected from screens and trays filled with, first, items to be heated (microwaved) and then nonheated items—for delivery to the consumer in less than 1 minute. Technological Advances Technologies such as hydrogen generation and utilization, micro nuclear reactors, new solar technologies, novel battery materials capable of storing and delivering higher energy densities, more rapid methods of charging and swappable battery technologies—all of these will enable and accelerate the application of electric and electronic technologies in the food processing industry. In addition, smaller, modular, compact, flexible, and more mobile processing systems will be enabled by new thermal and nonthermal technologies. Can food processing keep pace with global population growth? Some of these developments are already in progress, with the advent of small, integrated, precision-scale processing systems that can be deployed to areas of high preharvest value and used to develop products that reduce postharvest losses and waste. For example, in 2020 the Tibbetts Award was presented by the Small Business Administration and Small Business Innovation Research program to a company that developed a small-scale, onsite food processing system to reduce widespread vitamin A deficiency in sub-Saharan Africa. The world cannot afford to leave high-nutrient crops and crop waste in the fields. Processing and preserving at or near the field site drastically reduce or eliminate transport losses and onsite crop waste. New Expectations: “Functional Foods” Raw inputs for foods fall mainly into two categories: animal and plant. With animals bred for consumption, selected parts are harvested for processing into a consumer packaged product (parts not suitable for human consumption find other processed product markets). Much effort has gone into reducing possible contamination and lowering energy and water use while maximizing profits. Similar aspects are seen in plant processing: reducing the waste stream, reducing energy use, and maximizing consumer appeal while maintaining product integrity and nutrient retention. Processing and preserving at the field site drastically reduce or eliminate transport losses. In addition to the overall driving forces of food safety and profitability, agriculture is under more and more pressure to not only generate food but also improve consumers’ health. “Functional foods” (those reported to have positive effects on health beyond basic nutrition) may offer benefits in terms of gut health, reduced cancer risk or improved resilience and recovery, better heart health and cholesterol levels, a stronger immune system, energy boosts, and brain stimulation. To address these needs and interests, agrifood businesses are increasingly driven by research and development to ensure nutrition and support consumer health and wellness. As animal and plant R&D results in more functional foods, it becomes the food processing engineer’s job to retain product function all the way to the consumer. Advances in Packaging Technology Canning remains the most popular worldwide mode of preservation, and it was used long before people understood its principles. Canning knowledge took decades to develop, and every year more is learned about this traditional processing technique. Novel sterilization processes for foods require a “letter of no objection” from the Food and Drug Administration before production. Aseptic Packaging In the early 1950s industry pioneered the technology of aseptic packaging: sterilizing the package (e.g., a plastic or laminated cardboard carton) and filling it with sterilized product under sterile conditions. This technology ensures quality retention, allows regenerative heating (saving vast amounts of process energy), and lowers shipping costs since packaging materials are lightweight compared to cans and glass containers. During the 1970–80s, intensive industrial and academic activities were focused on developing engineering solutions to sterilize products containing particles in continuous flow (e.g., soups and stews) and packaged in a presterilized container under sterile conditions. Documenting the least heated portion of the flow was the main issue and the subject of many studies worldwide (e.g., Larkin 1997). Initially, mechanical methods were tried to “hold” the particles for a required time while the fluid passed. These methods were unsatisfactory. The early 2000s saw sensor technologies that solved the problem (Swartzel and Simunovic 2004). Systems slowly began taking advantage as regulatory hurdles were overcome. Uniform Heating The science needed to document the least heated spot in a processed can of food is now well developed. But challenges remain. For example, varying degrees of heat treatment are still required for a can’s contents. Thoroughly heating the largest can (#10) filled with a thick puree to a safety regulation–required temperature could take as much as 2½ hours and would both dramatically overprocess the product near the can’s surface and reduce nutrient quality and functionality. (Liquids, such as milk, can be heated while being pumped through the heat exchanger, rendering a near uniform treatment of the product.) Researchers turned their interest to novel heating methods in an effort to capture the most uniform rapid heating possible; they studied systems using electric resistance, pulsed-field, and microwave heating -methods. Nonthermal systems like high pressure, pulsed electric field, ultrasound, and cold plasma were examined since processing at near room temperatures was thought to preserve food quality to the highest degree. However, components like enzymes were often not inactivated in nonthermal systems and caused food deterioration during storage, or were useful only for refrigerated products with limited shelf lives. Continuous flow microwave technology yielded many of the desired answers. It is extremely fast and has uniform heating, providing a high-quality product. It also has very low energy loss compared to conventional canning operations, and is suited to almost all types of products with or without particles and a wide range of viscosities. Today rapid cooling methods are being examined and may soon add to the benefits of rapid continuous thermal flow processing. Shelf-stable products have extremely long shelf lives at ambient temperatures without any need for refrigerated or frozen storage throughout their life cycle—from production to consumption. With the new technologies that use continuous flow microwave, many frozen products today can easily be made shelf stable. Nonfluid products can now take advantage of sterile -chamber microwave treated processing (Tang and Liu 2018). Moving product out of the freezer while preserving high quality yields multiple energy savings from shipping through distribution and preparation. Food Processing for Tomorrow A paradigm shift in the agrifood processing industry is way overdue. With the new tools available, how will food processing plants be transformed to meet global needs? An integrated approach to processing, distribution, storage, preparation, and presentation will minimize labor and handling, and reduce meal component degrada-tion and energy use, food and packaging waste, and environmental impacts. Further advantages include increased food safety, security, and convenience while adding to nutrient and quality retention. Growth in the aseptic industry may lead to smaller processing plants close to the raw products, leaving product waste to be recycled locally or used in a local biofuels operation or as animal food. Less weight would need to be transported. Only finished goods in large sterile bags supported by reusable lightweight containers would be shipped from the processing plant. Aseptic transfer for meal assembly does not exist, although the benefits are enormous. A multitude of organizations must work together to change the paradigm of onsite mass meal preparation and delivery. As an example, chilled soups dominate many local restaurants in the warmer months. In most cases ingredients are combined from a washed raw state, sometimes with dairy products or other low-acid ingredients. Products are made in the morning, refrigerated, and served throughout the day. No processing and no heating step is included. What is left over is dumped. Food safety and waste issues abound. There is another way. Rapid volumetric heating methods can render the product sterile without affecting the fresh chilled flavor that appeals to customers. Such products have unlimited shelf life, are sterile and high in nutrient retention, and create no product waste at the end of the day. Additionally, these products can be provided year round. Fast food dominates Americans’ food consumption, driven by cost and convenience. A number of operations in the fast food industry have the potential to change to yield lower costs, lower waste, higher quality, and better customer satisfaction and health. For example, nearly all fast food restaurants (millions worldwide) sell soft serve ice cream in cones, sundaes, and milk shakes. It comes from refrigerated ice cream mix in bags. The bags are poured into a barrel freezer, where freezing times can take 30 minutes or more. A set quantity is made in each batch. At closing time any product left over is dumped and then an hour or more is needed to clean the barrel freezer for the next day. Multiple freezers are needed as flavors cannot be mixed. Rapid volumetric heating methods can sterilize a food product without affecting the fresh flavor that appeals to consumers. But now ice cream can be made on demand using liquid nitrogen. With this method it is never necessary to waste either unused mix or leftover product. The mix remains sterile and is dispensed as needed without contaminating the product in the bag. No product need be left in a freezer barrel, nor is so much cleaning necessary since only the filling nozzle has to be cleaned. Food processing innovations can also benefit other industries. For example, rapid freezing can be adapted for freeze drying medical supplies (e.g., blood plasma). The current freeze drying operation can take from several hours to days; rapid liquid nitrogen freezing followed by rapid microwave drying would decrease the time to minutes. Product damage, if any, would be minimal and costs would drop. Food process engineering advances are leading the way to ensure that foods are safe, quality is retained, energy and waste are reduced, and new ventures and markets are captured. References Benjamin EJ, Virani SS, Callaway CW, Chamberlain AM, Chang AR, Cheng S, Chiuve SE, Cushman M, Delling FN, Deo R, and 41 others. 2018. Heart disease and stroke statistics–2018 update: A report from the American Heart Association. Circulation 137(12):e67–e492. Bittman M. 2008. Rethinking the meat-guzzler. New York Times, Jan 27. FoodPrint. 2022 (updated from 2018). The problem of food waste. https://foodprint.org/issues/the-problem-of-food-waste/ Howard D. 2012. Interview with Dr. Philip Nelson, 2007 World Food Prize Winner. IFIS Publishing. https://www.worldfoodprize.org/en/laureates/20002009_ laureat es/2007_nelson/ Knorr D, Khoo CSH, Augustin MA. 2018. Food for an urban planet: Challenges and research opportunities. Frontiers in Nutrition 4:73. Larkin JW. 1997. Workshop targets continuous multiphase aseptic processing of foods. Food Technology 51(10):43. Pew Research Center. 2022. 10 projections for the global population in 2050. Washington. Swartzel KR. 2000. Engineering the future. Food Technology 54:246. Swartzel KR, Simunovic J. 2004. System for measuring residence time for a particulate containing food product. US Patent 6,766,699. Tang J, Liu F. 2018. Microwave sterilization or pasteurization methods. US Patent 9,961,926B2.  https://tibbettsawards.com/sinnovatek/ About the Author:Josip Simunovic is a research professor, North Carolina State University (NCSU), and founding codirector, NSF IUCRC Center for Advanced Processing and Packaging Studies. Kenneth Swartzel (NAE) is the William Neal Reynolds Distinguished Professor Emeritus at NCSU.