For about 200 years we’ve canned food in much the same way, putting it in cans (hence the name) and heating it under pressure for long periods. The heat both cooks the food and kills the bad little critters in the food. But heating the food for a long time is the reason why canned green beans are not like freshly cooked green beans and why canned salmon and chicken just are not like their freshly cooked equivalents. Canned food is better than nothing – because it keeps, because it’s safe and because some of us actually like mushy baked beans from cans. But compared to fresh food, most canned food runs a distant second best.
Many food companies, food scientists and a variety of engineers have tried their hand in recent decades at the project of finding a way to heat food and its container much more quickly and effectively. The goal has been to dramatically lower high temperature cooking times so that taste, texture and nutrition of the fresh food can more closely be preserved. But most of the past efforts have failed.
But the good news is that, on the campus of Washington State University, Dr. Juming Tang is making great strides in bringing to your grocery store exactly what the doctor ordered. The food’s safety has been demonstrated (even the worst case “bugs” are killed). It gives us better taste, texture and appearance (so people prefer the food). All this means it’s what is known as a “shelf stable” meal that will taste and look much more like freshly cooked food, not like a traditional dollop of canned spinach oozing on your plate.
Tang and his team recently got Food and Drug Administration approval for one process, a crucial first step in cooperating with a consortium of companies and entities to bring the basic technology to market and then consumer products to a store shelf near you.
“This is the 21st century approach,” Tang said in his lab. “In ten years, I believe that most companies that currently produce shelf-stable or refrigerated meals will use this technology.”
The new processing technique depends on hot water and long-wave microwaves. (Dr. Tang’s microwave isn’t like the one you’ve got at home; his fills a very large room.) The microwaves focus energy onto the food. Careful and clever engineering, and the flowing hot water bath, keep the heat distributed, even at the corners, and fully up to temperature.
While a traditional canning plant has large boilers and is filled with humidity and wasted energy, this new approach can be much more efficient, cost effective and environmentally friendly. It also provides a better work environment.
“The electricity for the microwave can come from wind or solar, and the heat for the hot water can come from the waste heat of the long-wave microwave,” Tang said.
The Army likes what it sees in the product of the WSU technology. Improving the shelf-stable foods that soldiers in the field live on is always one of its priorities since, as Napoleon once commented, armies march on their stomachs.
Major food companies are also paying a lot of attention to this project, and that’s where you and I come in. If Tang and colleagues are successful – and I believe they will be – you can look for pouches or trays of food made from their process on the grocery shelves just a few years down the road.
Tang is the first to say he doesn’t know how all the dollars and cents may work out. But the food companies that have seen his technology – and seen and tasted his products – are excited to explore this wholly new way of preserving food. They know which way the wind is blowing for cans.
Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. Follow her on the web at rockdoc.wsu.edu and on Twitter @RockDocWSU. This column is a service of the College of Sciences at Washington State University.