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Freezing and then reheating bread helps form resistant starch, slowing down sugar absorption and benefiting digestion.

Many people freeze bread to prevent mold. However, according to nutrition experts, this preservation method also changes the chemical structure of the bread, offering unexpected health benefits compared to storing it at room temperature.

When baked, the starch in bread expands (gelatinizes), making it easier for the body to digest but also causing a rapid increase in blood sugar. However, when the bread cools and is refrigerated, a process called "starch re-regulation" occurs. Starch molecules rearrange themselves, converting into "resistant starch"—a type of fiber that is more difficult for the body to break down.

Nutritionist Avery Zenker (USA) says that storage temperature is a key factor. The refrigerator's crisper drawer produces the most resistant starch but also causes the bread to dry out and harden quickly due to water loss.  Meanwhile, freezing helps bread retain its texture and flavor better, while also promoting the formation of resistant starch, especially after thawing and re-baking.

A study published in the European Journal of Clinical Nutrition showed that frozen and re-baked bread can reduce the glycemic response by nearly 40% compared to fresh bread. This means the body absorbs fewer calories and blood sugar levels are more stable after eating.

Illustrative image: Healthline

Resistant starch acts like fiber. Instead of going straight into the bloodstream as glucose, it travels to the large intestine, becoming food for beneficial bacteria and producing butyrate – a short-chain fatty acid that improves gut health and reduces inflammation.

To apply this method effectively while maintaining taste, experts recommend wrapping the bread tightly before freezing to prevent odor absorption or dehydration. When eating, reheating in an oven or microwave not only makes the bread soft and delicious but also optimizes the amount of resistant starch.

However, storage isn't everything. Nutritionist Sarah Glinski (Canada) notes that for truly healthy consumption, users should prioritize whole-wheat bread, sourdough bread, or breads with seeds (chia, flax, sunflower).  An ideal slice of bread should contain at least 3g of fiber and less than 3g of added sugar.

To keep your bread delicious and maximize its health benefits from resistant starch, follow these steps:

Step 1: Divide into portions. For large loaves or sandwiches, slice into bite-sized pieces before freezing. This makes it easy to take the right amount without thawing the entire loaf, preventing damage to the bread's structure due to temperature changes.

Step 2: Seal tightly. Wrap each slice or small portion in plastic wrap or aluminum foil, then place in a zip-lock bag or airtight plastic container. This step is important to prevent freezer burn – the bread losing moisture, drying out, and absorbing the smell of raw food in the freezer.

Step 3: Storage time. Bread can be stored in the freezer for 1 to 3 months.  However, it's best to consume it within the first month to ensure the best flavor.

Step 4: Reheat before eating. This is a crucial step to increase the amount of resistant starch. You can take the bread from the freezer and place it directly into a toaster, oven, or air fryer at approximately 160-180°C for a few minutes. If using a microwave, sprinkle a little water on the surface of the bread to prevent it from becoming dry and tough.