Food for Thought

The Engineer Who Came to Dinner

NEW YORK - Remember when the frozen "TV dinner" was the only convenience food around? If you do, it's not so much a reflection of your age, as of the rapid changes in food technology.

Whether they're more convenient, tastier, fresher, more nutritious, or just more fun, many of today's foods are engineering achievements. And, engineering achievements are celebrated during National Engineers Week, February 22-28.

What do engineers have to do with food? The question might actually be, what don't they.

According to most reports, agriculture and food processing account for 20 percent of the nation's gross national product. Many of the 1.8 million engineers in the country work on getting food to your table every day, as well as on special things like Valentine's Day chocolates and food for astronauts on the Space Shuttle.

Of course, a food engineer's most important job is to ensure food safety, supply, nutrition, and stability. But, beyond these basics, engineers continue to work to make food tastier, more convenient, and more appealing.

While TV dinners, now 42 years old, may not inspire the excitement they once did, even some recent innovations are pretty much taken for granted. One example is TetraPak™ juice boxes, which combine added convenience with improved product quality and stability.

Recently, with concerns about landfill capacity, engineers have looked more closely at how to make food packaging more environmentally friendly.

Everyone's familiar with decaffeinated coffee. Yet how many realize that engineers developed the supercritical carbon dioxide process to remove caffeine from coffee without using traditional hydrocarbon solvents? Now, we can all sleep better.

And, what about the ubiquitous microwave and microwavable food, not to mention freeze-dried and dehydrated foods, boil in a bag, and all the other forms of food packaging? All were developed by engineers.

To wash all this food down, you might drink milk bought right off the grocery shelf-without refrigeration. Using ultra-high temperature processing, engineers have developed a way to keep milk fresh longer, even at room temperature. Of course, this is just the latest development in a series of engineered advances for milk that includes vitamin fortification and lactose-free and low-fat varieties.

For dessert, how about some engineered ice cream? Frozen desserts, like ice cream, have presented unique challenges to engineers. Ice cream is a three-phase emulsion system (oil, water, and air) which has to be delicately balanced to provide the desired product characteristics. Processing conditions such as freezing rate influences the rate of ice crystal formation and has an effect on the resulting texture and "mouthfeel" of the product. Formulation plays a role as well - when different flavors, fruits, and colors are added, the balance of the system is altered.

Food provides a special challenge to engineers, because it is not as simple as other systems where physical and chemical properties are well defined and compositions known. Most foods are complex mixtures made up of thousands of compounds. Although food's chemical components can be broadly categorized as proteins, carbohydrates, fats, vitamins, minerals, flavors, and enzymes, this simplification does not truly reflect the variety of compounds within each class.

What complicates matters more is that the compounds all interact with each other. And, processing food in the plant or cooking it at home changes the flavor, color, and nutritional characteristics.

Food engineers are also involved in cutting-edge technologies, like genetic engineering, to produce crops more resistant to pests, or more durable for processing. In processing, newer technologies such as freeze drying or supercritical extraction are used in cases where maintaining heat-liable compounds (such as flavors) are important.

How is a typical new food "engineered?" After a product concept is developed in a lab, it is done "bench-scale," where there is close control of composition and processing. One of the engineer's tasks is to translate a lab process to large-scale production. The product also has to be packaged in a way to ensure easy distribution and preparation. And, through the entire interval, from the time the product leaves the plant until it is served at the table, it must maintain its quality.

Established products must be continually "re-engineered" to give them advantages over the competition. These include better overall flavor (or more variety), making the packaging more recyclable, reducing manufacturing costs, improving nutrition, or innovations for added convenience.

What will tomorrow's foods be like? Ultimately, it depends on what consumers want. But, you can be sure that engineers will be working to make that food safe, more nutritious, convenient, and tastier.

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