STORING FOODS TO RETAIN QUALITY
HOW YOU STORE DRY AND FROZEN FOODS MAKES A HUGE DIFFERENCE
One of the most popular parts of my seminars is the discussion of proper storage of dry and frozen foods. It makes no sense to buy expensive, premium dog foods, whether dry or frozen, and then ruin them—actually making them unhealthy—by storing them too long or improperly. Recently produced, mass-market food is probably better than super-premium, top-of-the-line foods that have sat on the shelf for months. Here’s some important advice on ensuring the foods you buy are at their best when you feed them.
Dry foods: Buy recently produced and use up within 14 days after opening.
Would you keep a loaf of bread open in your kitchen or garage for 39 days? I hope not. That’s how long the typical purchased bag of dog food remains open before completely consumed. This lengthy shelf time, combined with often poor storage conditions, leads to oxidation of fats, nutrient degradation, and infestation by molds, mites, and other food spoilers. One in three dogs dies of cancer, and I think improper storage at home is a contributing factor.
Dry dog foods usually have a one-year “shelf life.” That means the food is “good” for up to one year after the manufacturing date. Many dry foods stamp a “best if used by” date on the package. This applies only to unopened bags.
If the bag is intact, without any holes or tears, not enough oxygen can migrate into the food in one year to cause significant oxidation, nutrient degradation, or microbial growth problems. But as soon as you open the bag of dog food, oxygen, moisture, light, mold spores, storage mites, and other potential spoilers enter the bag.
Oxidation of fats. Dog food companies use antioxidants (sometimes vitamin E and other natural sources) to forestall oxidation. Over time, with continual exposure to oxygen whenever you open the bag (and the bags are not perfect oxygen barriers either), the anti-oxidants are eventually all oxidized (used up) and the fats, beginning with the more fragile omega-3s, start turning rancid. As discussed above, studies show that frequent consumption of oxidized fats may cause cancer and contribute to many chronic health problems.41
Degradation of all micronutrients. The nutrition in the food at the bottom of a bag left open 39 days will be considerably reduced compared to that of the top of the bag. Vitamins particularly susceptible to loss of potency due to long-term room temperature storage include vitamin A, thiamin, most forms of folate, some forms of vitamin B6 (pyridoxal), vitamin C, and pantothenic acid.
Molds and mycotoxins. Storing open bags of dry dog food for 39 days in warm, humid areas (most kitchens) promotes the growth of molds. Some of the waste products of these molds (mycotoxins) are increasingly being implicated as long-term causes of cancer and other health problems in humans, poultry, pigs, and other animals. Dogs are particularly susceptible to these toxins.42
When dry dog foods absorb moisture from the surrounding air, the antimicrobials used by manufacturers to delay mold growth can be overwhelmed, and mold can grow.43 The molds that consume dry pet foods include the Aspergillus flavus mold, which produces Aflatoxin B1, the most potent naturally occurring carcinogenic substance known.
People can’t see low levels of mold with the naked eye, and most dogs can’t taste it.44 While some dogs have died shortly after eating mycotoxin-contaminated foods, mycotoxins kill most dogs slowly by suppressing the immune system and creating long-term health problems in all organs of the body.45, 46 This topic is covered at length in See Spot Live Longer.
Infestation. Bugs, storage mites, mice, and other unpleasant invaders thrive on dry dog food. Recent research has shown that allergic dogs frequently have reactions to the carcasses of storage mites. Storage mites may infest grains, especially those grains used in low cost dry dog foods.
Strategies to enhance storage life of dry food
Here are my recommendations:
1. Keep food in its original bag, even if you use an airtight container. Pouring the food out exposes all the pieces of kibble to air, increasing the potential for oxidation.
2. Buy small, recently produced, bags of food. Look for manufacturing or “best if used by” dates on the bag. If you don’t see one, ask the retailer for the date. If you can’t understand the code, ask the retailer to interpret it for you.
3. Once opened, plan to have food consumed within 7 days.
4. Keep food dry. If the food looks moist, throw it away.
5. Keep larger bags in the freezer.
6. If the food has changed color, throw it away.
7. If the food smells rancid or like paint, throw it away.
8. If your dog refuses to eat at mealtime, do not force her to eat.
9. Don’t buy bags that are torn.
These storage strategies are based upon an article written by Steve Brown and Beth Taylor, originally published on www.mercola.com.
The shelf life of commercial raw diets: three months
If you are feeding commercially prepared raw foods, it’s important to buy recently produced frozen foods. Even if the meats and vegetables are all organic and the fats perfectly balanced, it is not a “quality” product, by USDA definition, if it is older than four months old. I’d prefer even fresher food.
Freezing is the best way to preserve meats, but the nutrients in the meat still degrade and the fats oxidize, even at 0 degrees F. Whole frozen meats have up to a one year “shelf life” in the freezer. However, ground meats—the number one ingredient in almost all commercial frozen raw diets—have a much shorter shelf life.
According to the USDA, ground meats, to be considered quality, have 3 to 4 month shelf lives when frozen. Here is a portion of the USDA frozen storage chart, based on frozen meats kept at a constant 0 degrees F (-18 degrees C).47
Grinding meats break the protective cell walls of the meat and fat cells, making the fragile nutrients more exposed to oxidizing agents, including the copper and iron released by the broken cells. These metals speed up the oxidation process.
Once the ground meat is frozen, oxidation and destruction of nutrients does not stop. Unless the food is packaged in glass or metal and is never opened, oxygen migrates into the food and oxidation occurs. The fats slowly turn rancid and the vitamins and antioxidants slowly degrade. The nutrients are further damaged by the growth of ice crystals. When raw meat freezes, the water within the meat forms ice crystals; the ice crystals grow even at a steady 0 degrees F. The longer the time in the freezer, the larger the ice crystals become, and the more likely that they will further puncture cell walls, and break some of the double bonds in the polyunsaturated fats.
The way most raw diets are made—using ground meats mixed with vegetables and other nutrients—can accelerate degradation of nutrients, and shortens the shelf life. Ground vegetables are mostly water, which, when frozen, form more ice crystals, further damaging nutrients. Added fish oils shorten shelf lives further because the ice crystals can break some of the double bonds of the polyunsaturated fats. Ground fish products have the shortest shelf lives of all animal protein.
The best way to ensure that you are buying a quality (by USDA definition) product, is to look for the “produced-on date,” and then buy only products that are less than three months old. Many raw diet manufacturers give their products 12-month shelf lives (I did at my company, Steve’s Real Food, until I learned better), and place “best if used by” dates on their labels. In retrospect, this was not good enough as the buyer needs to know when it was produced. If you can’t make that determination from the packaging, contact the manufacturer or ask your retailer how to determine when the product was produced. Demand freshness.