- Phytate is considered an anti-nutritional factor because it binds to minerals such as iron, zinc, and calcium, reducing their bioavailability. It is commonly found in seeds and grains.
- Isoflavones are plant compounds found in soy and other legumes. They are not considered anti-nutritional; in fact, they are often beneficial due to their estrogen-like effects.
- Trypsin inhibitors are compounds that inhibit the enzyme trypsin, which is necessary for protein digestion. While trypsin inhibitors are anti-nutritional factors, they are not as widely impactful as phytates.
- Resveratrol is an antioxidant found in red wine, grapes, and some berries. It is not an anti-nutritional factor but has potential health benefits.
Final Answer:
\[
\boxed{\text{Phytate}}.
\]