Grocery & Nutrition • Jul 18, 2019
Let’s take a quick look into canned goods. When did they come onto the food scene? What are the benefits? What are the pitfalls? And ultimately, what should you be looking for when you are shopping the canned food aisle?
In 1795 the French government offered a reward to anyone who could invent a new method of preserving food for the military. After much experimentation, Nicolas Appert won the prize in 1809 and introduced the world to canning. The canning process involves four steps: the food is processed (washed, peeled, chopped, blanched, etc)., then put into jars/cans and the lid is sealed, the jar/can is heated to destroy bacteria, then it is cooled quickly. (1)
Affordability: Canned foods are typically less expensive than their fresh counterparts.
Less Food Waste: Canning allows for foods to be preserved before they spoil.
Time-Saving: Canned beans can be prepared much faster than the dried version and can be used as a protein source in a main dish, or to make a quick hummus spread. Canned tomatoes speed up the process of making your own pasta sauce, chili, or soup. Create a quick chicken or tuna salad using their canned varieties. Canned pumpkin not only makes a quick pie at Thanksgiving, it can also be used for muffins and pancakes.
Food goes through a process of preparation, high heat and rapid cooling to get into the can safely, all of which changes it from it’s fresh counterparts. A review in the Journal of the Science of Food and Agriculture looked at a collection of research comparing the nutrient content of fresh, frozen, and canned fruits and vegetables and here are the biggest findings:(2,3)
Vitamin C: Vitamin C is heat-sensitive so the cooking involved in the canning process can decrease this nutrient. When tomatoes, broccoli, green beans, asparagus, corn, and mushrooms were studied, all found a decrease in vitamin C during this process.
Riboflavin: Riboflavin is sensitive to processing. If you are looking for Riboflavin research has shown that sweet potatoes, asparagus, and peaches retain 95% after processing, while lentils and mushroom to retain 68%.
Alpha-tocopherol (vitamin E): Canned tomatoes have more vitamin E than the fresh varieties; however canned asparagus had lower amounts than the fresh and frozen varieties.
Beta-carotene: Apparently the jury is still out on this one. One study showed increases in carrots, collard greens, spinach, and sweet potatoes, but decreases in peaches and tomatoes after canning, while another showed increases in peaches but decreases in green beans and sweet potatoes.
Low sodium or no salt added: Sodium can be pretty high in some canned goods so be sure to check the label. If possible, select a low sodium variety. Tip: draining and rinsing canned foods can decrease the sodium content.
Packed in juice or no-sugar-added: Canned fruits are sometimes packed in syrup which means a lot of added sugars.
BPA-free: Cans are typically lined with BPA, although some brands are changing that. BPA is a chemical used to make certain plastics and is an endocrine (hormonal) disruptor. Research shows that BPA in can liners can leach into food. The FDA claims that it is safe because it occurs in low levels in foods, however some studies suggest otherwise. (4)
While the heat necessary for the canning process can decrease some nutrients, canned foods can still be included in a healthy diet. Aim for a wide variety of fresh, frozen, and canned fruits and vegetables. Mix in canned foods when you need to save time, money, or need to preserve your own. Just be sure to look for items that stay true to the original ingredients (no added salt, sugar or BPA). Oh, and be sure to recycle those cans!