High and low oxalate content in spinach: an investigation of accumulation patterns

BACKGROUND Oxalic acid is a common antinutrient in the human diet, found in large quantities in spinach. However, spinach is highly regarded by vegetable producers because of its nutritional content and economic value. One of the primary purposes of spinach-breeding programs is to improve the nutritional value of spinach by adjusting oxalate accumulation. Knowledge of the biosynthetic patterns of oxalic acid, and its different forms, is important for a better understanding of this process. RESULTS We found three biosynthetic patterns of accumulation and concentration of oxalates. Two of them are related to the maximum type and one is related to the minimum type. We also developed a general model of variations in these compounds in the genotypes that were studied. CONCLUSION This study introduced a unique type of spinach with high oxalate accumulation, which could be particularly suitable for consumption. This had the highest ratio of insoluble oxalate to soluble oxalate. It also accumulated more ascorbic acid (AA) than other types. Our findings in this study also indicate a small role for AA as a precursor to oxalate production in spinach, possibly confirming the significant role of glyoxylate as the most critical precursor in this plant. (c) 2021 Society of Chemical Industry.

Automated summary

This study identified three biosynthetic patterns of oxalate accumulation in spinach and introduced a unique type with high oxalate accumulation, which could be beneficial for improving the nutritional value of spinach. The research also suggested a small role for ascorbic acid as a precursor to oxalate production in spinach, highlighting the significance of glyoxylate as the most critical precursor in this plant.