Understanding Oxalates in Almonds
Almonds are a nutritious food, packed with healthy fats, protein, and essential minerals. However, they are also known to be high in oxalates, a natural compound found in many plants. For most people, consuming oxalates is not an issue, but for individuals prone to kidney stones, particularly calcium oxalate stones, a high oxalate intake can be problematic. Oxalates can bind with calcium in the digestive tract, preventing its absorption and potentially contributing to kidney stone formation. This concern often leads people to seek preparation methods that can lower the oxalate content of foods like almonds. One such method is blanching, which involves a brief dip in boiling water followed by skin removal.
The Science Behind Blanching and Oxalate Reduction
Blanching is a culinary technique that can be very effective in reducing the oxalate content of certain foods, including almonds. This process works primarily through two key mechanisms:
- Leaching into Water: The brief boiling period is the most important step for oxalate reduction. Oxalates are water-soluble, which means they can dissolve and leach out of the almonds and into the boiling water. The longer the exposure to boiling water, the greater the reduction of soluble oxalates. It is critical to discard this water after boiling to ensure the leached oxalates are removed and not reabsorbed.
- Skin Removal: While the skin contains fewer oxalates than the nut itself, it does contain other anti-nutrients. The blanching process makes the skin easy to remove, and its subsequent disposal contributes to the overall reduction of anti-nutrients in the finished product.
Evidence of Effectiveness
A compelling study cited on ResearchGate highlights the effectiveness of blanching. Researchers found that blanched almond flour (BMF) had a significant reduction in oxalate content compared to unblanched almond flour (UBMF), with one instance showing a 46.1% reduction. This evidence strongly supports the practice of blanching for those looking to lower their oxalate intake from almonds.
Comparison: Blanched vs. Unblanched Almonds
To better understand the differences, here is a comparison of key factors between blanched and unblanched almonds:
| Feature | Unblanched Almonds | Blanched Almonds |
|---|---|---|
| Oxalate Content | High | Significantly lower |
| Texture | Crunchy, with a slightly rough skin | Smooth and tender |
| Taste | More rustic, slightly bitter due to the skin | Milder and sweeter |
| Appearance | Brown, with intact skin | Creamy white, skin-free |
| Use in Baking | Can be ground for flours with stronger flavor | Ideal for smooth flours and delicate recipes |
| Digestibility | Can be harder to digest for some due to the fibrous skin | Generally easier to digest |
How to Blanch Almonds at Home
Making your own blanched almonds is a simple process that gives you control over your food's oxalate content. You can follow these steps:
- Bring a pot of water to a rolling boil.
- Add raw, unroasted almonds and let them boil for exactly 60 seconds.
- Immediately drain the almonds and plunge them into a bowl of ice-cold water to stop the cooking process and loosen the skins.
- Drain the cooled almonds. The skins will be loose and can be easily pinched off with your fingers.
- Lay the peeled almonds on a clean kitchen towel to air dry completely before using or storing.
Other Preparation Methods to Reduce Oxalate
While blanching is effective, other techniques can also help reduce oxalate levels in almonds:
- Soaking: Soaking almonds overnight in water can help reduce their soluble oxalate content. The enzyme inhibitors on the nut's surface are also removed, which can improve digestibility. Just like with blanching, remember to discard the soaking water.
- Sprouting: Sprouting is another process that can help decrease oxalate levels in almonds by activating enzymes that break down anti-nutrients.
The Verdict on Blanched Almonds and Oxalates
Ultimately, the answer is a resounding yes: blanched almonds do have less oxalate. The process of blanching, which involves a brief boil and the removal of the skin, significantly reduces the soluble oxalate content, making them a more suitable choice for individuals on a low-oxalate diet. While the reduction is substantial, it is important to remember that almonds are naturally high-oxalate food, and portion control remains a key strategy for managing intake. Combining blanched almonds with low-oxalate, calcium-rich foods can also help minimize absorption. By understanding the science and employing proper preparation methods, you can make informed choices to support your health goals.
For additional dietary guidance and information on oxalate reduction, consulting authoritative resources like The Kidney Dietitian can provide valuable insights.
Conclusion
In summary, the practice of blanching almonds and removing their skins provides a proven method for reducing their overall oxalate content. The brief boiling period effectively leaches water-soluble oxalates, a key step for anyone mindful of their oxalate intake. This makes blanched almonds a superior choice for baking and general consumption if you are following a low-oxalate diet. While blanching offers a significant advantage, it should be part of a broader dietary strategy that includes portion control and considering other low-oxalate nut alternatives like walnuts or macadamia nuts.
