AbstractGenetic engineering offers great potential for developing peanut cultivars resistant to a broad spectrum of pathogens that pose a recurring threat to peanut health. In an effort to improve the disease resistance of peanuts, three transgenic peanut lines were developed. Somatic embryos of the peanut cultivar Okrun were transformed by inserting a chitinase gene from rice and/or a β‐1‐3‐glucanase gene from alfalfa. The main objective of this research project was the assessment of composition of the nutritionally beneficial bioactive components in biotechnology‐derived peanut lines. The transgenic peanut lines 188, 540 and 654, which showed increased resistance to fungal diseases, as compared to the parent line, were analyzed for their tocopherol, phytosterol and phospholipid compositions. The compositions of transgenic lines were compared to those of the parent cultivar. The experimental results indicate no major changes in the composition of transgenic peanut lines examined in this study with respect to the cultivar Okrun. Copyright © 2005 Society of Chemical Industry