Bioaccessibility of polyphenols from selected cereal grains and legumes as influenced by food acidulants.

BACKGROUND: Polyphenols in food are valued for their health-beneficial influences. Food acidulants lime juice and amchur used in Indian cookery were evaluated for their influence on polyphenol bioaccessibility from food grains.
RESULTS: Lime juice increased bioaccessible flavonoids by 25% in roasted finger millet, while there was no change in total bioaccessible polyphenols in pressure-cooked, open-pan-boiled and roasted finger millet in the presence of food acidulants. Addition of amchur to pressure-cooked and microwave-heated pearl millet increased bioaccessible flavonoids by 30 and 53% respectively, while lime juice increased them by 46% in pressure-cooked pearl millet. Increased bioaccessibility of specific phenolic acids from finger millet and pearl millet was observed upon addition of these food acidulants. The presence of either lime juice or amchur increased bioaccessible flavonoids from both legumes studied. Addition of lime juice and amchur, however, exerted a negative effect on the bioaccessibility of several phenolic compounds from food grains in native state and under certain processing conditions.
CONCLUSION: Thus food acidulants lime juice and amchur had a significant influence on the bioaccessibility of health-beneficial phenolic compounds from food grains. Use of food acidulants in food preparations could be a strategy to enhance the bioavailability of polyphenols, especially flavonoids from grains.