Isoflavones in chickpea (Cicer arietinum) protein concentrates

• Chickpea protein concentrates are potential sources of healthy isoflavones.
• Protein concentrates are enriched in isoflavones as compared to the original flour.
• Derivatives of biochanin A represent 90% w/w isoflavones in flour (9 µg/g).
• Biochanin A aglycone represents 93% w/w isoflavones in concentrates (31 µg/g).
• Formononetin and genistein were also present at much lower concentration.

The isoflavones in chickpea concentrates were analysed and compared to the original flour. Protein concentrates were prepared by alkaline extraction and precipitation of protein at the isoelectric pH. HPLC analysis revealed that the concentrates were enriched in isoflavones. The concentration of total isoflavones was 45 and 10 µg/g in concentrates and flour, respectively. Isoflavones in flour were hydrolyzed to the corresponding aglycones during alkaline extraction. While hydrolyzable derivatives of biochanin A represent 90% (w/w) total isoflavones in flour (9 µg/g), biochanin A aglycone was the major isoflavone in concentrates (31 µg/g). Minor components were formononetin, genistein, and the flavonol kaempferol. Thus, chickpea protein concentrates represent an even better source of health-promoting isoflavones than the original chickpea.