Seeds are hot stuff these days because of their incredible nutritional value. Packed with protein, healthy fats, vitamins and minerals, seeds have long been a staple of Mediterranean and vegan diets.

Seeds are increasingly showing up in restaurant fare and in home-cooked meals. “People are looking for a lot of bang for the buck and seeds by their very nature are nutrient-dense” because they provide life for the new plants, explains Mary Ellen Camire, PhD, president of the Institute of Food Technologists and a professor of food science and human nutrition at the University of Maine. But there’s an art to buying and storing seeds to preserve freshness and prevent them from turning rancid.

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For starters, think twice about buying pumpkin and sunflower seeds in bulk from bins at health-food stores, Camire says, because “there’s a concern about insect contamination, freshness and allergen-potential [from cross-contamination].” Many seeds contain a fair amount of oil, which means they’re highly prone to spoilage. So “don’t buy a 10-pound bag of chia seeds or any other type. It’s better to buy a small bag that you can use in a few months,” Camire says. With most seeds, it’s best to store them in an airtight jar or package in the fridge or freezer to help them stay fresh for a few months, rather than a matter of weeks. Pantry storage is fine for smaller amounts that you’ll use quickly.

Here’s some seed-specific advice on how to store seeds and check their freshness.

Chia seeds                                                           (Photo: mchin/Shutterstock) 

Chia seeds. Regardless of where you store them, it’s best to give them a whiff before you use them. “If they smell fishy or like paint or paint thinner, they’re probably rancid,” Camire says, which means they’ve lost their nutritional punch. 

Packed with protein and fiber, these tiny seeds are also good sources of calcium, iron, magnesium, potassium and omega-3 fatty acids, which reduce inflammation, according to the Department of Agriculture (USDA). You can use them in oatmeal, muffins, smoothies, salads and puddings.

Flaxseeds                                                         (Photo: olgaman/Shutterstock) 

Flaxseeds. To optimize their nutrition, grind them right before you use them, Camire advises. 

A solid source of soluble fiber, flaxseeds are also loaded with anti-inflammatory omega-3 fatty acids and small amounts of calcium, magnesium, potassium and protein, the USDA says. Ground flaxseeds can be added easily to cereals, rice dishes, casseroles and yogurts.

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Pumpkin seeds                                                         (Photo: Denise Torres/Shutterstock)

Pumpkin seeds. Since they’re higher in oils than most seeds, pumpkin seeds (aka pepitas) can lose their freshness more quickly than others, Camire warns. It’s best to store them in a cold, dry place. 

They’re good sources of protein, fiber, iron, potassium, zinc and healthy fats, according to the USDA. They can be eaten raw, roasted as a healthy snack or used in salads, cereals, breads or muffins.

Black sesame seeds                                                          (Photo: busayamol/Shutterstock) 

Sesame seeds. Both the white and black variety are high in healthy, monounsaturated and polyunsaturated fats, which means they can spoil pretty quickly. Store them away from light, air and heat in a dark, cool place, Camire says, and replace them after four months if you’re keeping them at room temperature. 

An abundant source of protein, fiber, calcium and iron, sesame seeds can be used in stir-fries, dips, salads and as a coating for baked or broiled fish. Toasting sesame seeds cranks up their antioxidant content even more, Camire says.Sunflower seeds                                           (Photo: fotohunter/Shutterstock) 

Sunflower seeds. It’s best to keep the shelled seeds in the fridge in an airtight container to preserve their freshness. If they’re still in the shell, they can be kept in a bag in a cool cabinet. 

Whether you eat them in trail mix or salads, you’ll get plenty of protein, fiber, calcium, iron, magnesium, potassium, folate and vitamin E from these small seeds.

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Stacey Colino is an award-winning writer specializing in health, nutrition and fitness whose work appears in Dr. Oz The Good Life magazine, MORE, Family Circle, Parents, Real Simple and many others. She is also the co-author of the gluten-free cookbook “Good Food — Fast!”