Flaxseed is recognized for its beneficial omega-3 fatty acids, fiber, and lignans, contributing to its popular use. However, to preserve its freshness and nutritional integrity, proper storage is important. Flaxseeds contain delicate oils that are susceptible to degradation when exposed to elements like air, light, and heat, which can lead to rancidity and a reduction in their inherent value.
Storing Whole Flaxseed
Whole flaxseeds have a hard outer shell, providing a natural protective barrier against spoilage. Store them in an airtight container to minimize exposure to air and moisture. A cool, dark pantry or cupboard is a suitable environment, protecting the seeds from light and heat.
For extended freshness, refrigeration or freezing significantly prolongs their shelf life. Whole flaxseeds can typically last for 1 to 2 years when stored in a cool, dark pantry. If kept in the refrigerator or freezer, their longevity can extend to 1 to 3 years or potentially longer, as cooler temperatures effectively slow down the oxidation process of their oils.
Storing Ground Flaxseed
Ground flaxseed (flax meal) has a larger surface area than whole seeds. This increased exposure makes it more vulnerable to oxidation, degrading its omega-3 fatty acids quickly. Consequently, ground flaxseed has a significantly shorter shelf life than its whole counterpart. To prevent rapid spoilage, immediate refrigeration or freezing is recommended.
Ground flaxseed should always be kept in an opaque, airtight container to shield it from light and air. When stored in the refrigerator, it typically remains fresh for about 3 to 6 months. For even longer preservation, ground flaxseed can be stored in the freezer for up to 6 months to 1 year. Leaving ground flaxseed at room temperature is not advisable, as it can go rancid within just a few weeks or even days.
Recognizing Spoilage
Spoiled flaxseed shows distinct changes in sensory characteristics. A primary indicator of spoilage is a change in smell; fresh flaxseed has a mild, nutty aroma, while rancid flaxseed often emits a sour, stale, or fishy odor. Some may describe this unpleasant smell as chemical, similar to old paint or nail polish remover.
Another sign of spoilage is a shift in taste, where the flaxseed becomes bitter or sour instead of its usual nutty flavor. Visual cues can also signal that flaxseed has gone bad, such as discoloration, mold growth, or, in the case of ground flaxseed, the formation of hard blocks or clumps due to moisture exposure. Consuming rancid flaxseed is generally not recommended, as it loses its nutritional benefits and may cause digestive discomfort, though it is unlikely to lead to serious illness.