Phytic acid, or phytate, is a storage form of phosphorus found in many plant seeds, grains, and legumes. While it acts as an antioxidant and may offer some health benefits, it is primarily known for its ability to bind to minerals like iron, zinc, and calcium, hindering their absorption. The amount of phytic acid in peas is a common nutritional concern, and it is a topic well-researched by food scientists and health experts. The content is not static and is affected by several variables, including the pea variety and the culinary preparation methods used.
Phytic Acid Levels in Different Pea Varieties
Research has shown that the concentration of phytic acid can differ significantly across different pea types. Field peas, for example, tend to have higher levels of phytic acid and polyphenols compared to vegetable pea varieties. In one study on field peas, concentrations ranged from 0.5 to 2.5 mg/g sample, while genetically modified low phytic acid (lpa) lines showed 30-55% lower levels. This variation suggests that the specific type of pea you consume can influence your overall phytic acid intake. Dry peas, such as split peas, have also been a focus of research. For instance, a study on yellow shelled peas found phytic acid content between 0.49% and 0.86% in dry matter.
Effective Methods for Reducing Phytic Acid in Peas
Several traditional and modern food preparation methods can significantly reduce the amount of phytic acid in peas, making their minerals more bioavailable. The key is to break down the compound, which can be done through soaking, cooking, and fermentation.
Soaking and Cooking
Soaking is a foundational step that should precede any cooking of dry legumes. Phytic acid is water-soluble, and soaking pulses in water allows some of the compound to dissolve and leach out.
- Overnight Soaking: Soaking dry peas overnight in water can reduce phytate content. For instance, a 12-hour soak reduced the phytate content of certain peas by up to 9%.
- Soaking with Cooking: Combining steeping followed by boiling can be extremely effective. One study on Pakistani peas found an 82% reduction in phytic acid using this traditional method.
Germination (Sprouting)
Germination, or sprouting, is a highly effective way to reduce phytic acid. This process activates the intrinsic phytase enzyme within the seed, which actively breaks down phytate.
- Enhanced Reduction: Germination for 48 hours has been shown to have a marked lowering effect on phytic acid levels in peas. Longer germination periods lead to greater reductions, as the phytase enzyme continues to work.
Fermentation
Fermentation, which involves beneficial microorganisms, can also degrade phytic acid. The lactic acid produced during fermentation promotes phytate breakdown.
- Microbial Action: The enzyme phytase is also produced during fermentation, contributing to the breakdown of phytic acid into more bioavailable forms.
Pressure Cooking
While traditional boiling is effective, pressure cooking can accelerate the reduction process.
- More Efficient Reduction: A study on peas found that pressure cooking reduced phytic acid by 54% compared to a 29% reduction from conventional boiling, both preceded by an overnight soak.
Phytic Acid Levels in Peas: A Comparative View
To put the phytic acid content of peas into perspective, it is useful to compare it with other common legumes and foods. The amount of phytates can vary significantly across different plant-based foods.
| Food (per 100g dry weight) | Phytic Acid Content (grams) | Notes |
|---|---|---|
| Peas | 0.22–1.22 | Content can be reduced significantly with processing. |
| Lentils | 0.27–1.51 | Similar range to peas; reduction through processing is effective. |
| Chickpeas | 0.28–1.60 | Also have comparable phytate levels that can be lowered. |
| Soybeans | 1.0–2.22 | Generally higher phytic acid content than peas. |
| Almonds | 0.35–9.42 | Very wide range; higher potential phytic acid than peas. |
| Wheat Bran | 2.1–7.3 | Significantly higher in phytates than peas. |
The Role of Phytic Acid and Nutritional Implications
Despite being called an "antinutrient," phytic acid isn't always detrimental. At lower levels, it may offer some benefits, including antioxidant properties, blood glucose control, and even potential protective effects against colon cancer. However, the key concern for many is the impact on mineral absorption, particularly iron and zinc. This is especially relevant for individuals relying heavily on plant-based diets or those with existing mineral deficiencies. By using proper preparation methods like soaking, sprouting, and cooking, you can unlock the full nutritional potential of peas while minimizing the effects of phytic acid.
How to Incorporate Peas for Maximum Benefit
Incorporating peas into your diet is beneficial due to their high protein, fiber, and vitamin content. To ensure you're getting the most nutritional value, especially the minerals, focus on proper preparation.
- Start with dried peas and soak them overnight before cooking.
- Consider sprouting your peas to maximize the reduction of phytates.
- Cook soaked peas thoroughly; boiling and pressure cooking are both effective.
- Combine peas with vitamin C-rich foods. Vitamin C helps to enhance iron absorption, which can counteract the effects of any remaining phytic acid.
- Pair peas with alliums like garlic and onions, which also aid in mineral absorption.
Following these steps allows you to enjoy the nutritional benefits of peas while mitigating the inhibitory effects of their phytic acid. The goal is not to eliminate phytic acid entirely, but to manage it so your body can efficiently utilize the minerals in this healthy legume.
Conclusion
In conclusion, the phytic acid content in peas varies based on variety and preparation. While present, the levels are comparable to other common legumes. Fortunately, simple and effective methods like soaking, cooking, germination, and fermentation can significantly reduce phytic acid, thereby improving mineral bioavailability. Instead of avoiding this nutrient-dense food, employing these techniques allows for a balanced approach to nutrition, ensuring you receive the full spectrum of benefits peas have to offer. For those with specific health concerns, opting for low phytic acid pea varieties is also an emerging option. The ultimate takeaway is that strategic food preparation is key to unlocking the maximum nutritional potential of peas.
Visit the Wiley Online Library for more information on phytic acid reduction in pulses.
