Assessment of Biochemical Composition, Mineral Content, and Fatty Acid Profile in Maize (Zea mays) Cultivars Under Water Stress and Excessive Water Using Biplot Analysis

Understanding the impact of irrigation levels on maize (<i>Zea mays</i> L.) nutritional properties is crucial for optimizing water use in sustainable agriculture. This study investigates the effects of three irrigation levels (I75: 75%, I100: 100%, and I125: 125% of depleted water from field capacity) on the biochemical composition, mineral content, and fatty acid profile of five maize cultivars' grain. Biplot analysis was employed to identify superior irrigation levels and cultivars regarding nutritional traits and to visually interpret their interrelationships. The findings indicate that increased irrigation enhances oil, protein, ash, total starch, amylopectin, resistant starch, and non-resistant starch while reducing dietary fiber, phytic acid, and amylose levels. Mineral contents generally increased with irrigation, except for sulfur, which declined, and potassium, which peaked at I100 before decreasing. The fatty acid composition was largely cultivar-dependent, with no significant effect from irrigation. Among the tested irrigation levels, I100 was the most optimal, providing the best nutritional quality and mineral composition balance across the maize cultivars. Pioneer PR31Y43 and Syngenta Dracma cultivars stood out under limited irrigation conditions (I75), Pioneer PR31G98 and Tareks OSSK644 cultivars under optimum irrigation conditions (I100), and Syngenta Inove and Tareks OSSK644 cultivars under over-irrigation conditions (I125). These results highlight the necessity of cultivar-specific irrigation strategies to maximize maize nutritional quality and resource efficiency.