When evaluating pine nuts, prioritize moisture content (ideally below 3-5%) to prevent mold and rancidity. Check for uniformity in size and color, as high-quality kernels should be creamy white; any yellowing or dark spots may indicate oxidation. Ensure the purity rate is ≥99.9%, meaning the batch is free from shells, stones, or foreign materials. For B2B buyers, requesting a Certificate of Analysis (COA) that details peroxide values and free fatty acid levels is essential to guarantee freshness.