Polyphenols and tannins in Indian pulses: Effect of soaking, germination and pressure cooking

• Published in: Food research international 2010-03, Vol.43 (2), p.526-530
• Main Authors: Khandelwal, Shweta, Udipi, Shobha A, Ghugre, Padmini
• Format: Article
• Language: English
• Subjects: Analysis of variance; Bioavailability; Cajanus cajan; chickpeas; Cicer arietinum; cooking quality; cultivars; dietary protein; food nutrient losses; Foods; Germination; legume protein; legumes; Lens culinaris subsp. culinaris; Lens esculenta; lentils; mung beans; nutrient availability; nutrient content; Nutrition; Phaseolus aureus; pigeon peas; Polyphenols; pressure cooking; Soaking; Tannins; Vigna radiata var. radiata
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2009.09.036

Polyphenols and tannins have implications for health and nutrition. There is limited information on their content in pulses, raw or post-processing. We estimated the concentrations of polyphenols and tannins in different cultivars of four pulses commonly consumed in India – Phaseolus aureus, Cajanus cajan, Lens esculenta and Cicer arietinum – and examined the effects of domestic processing. Means and standard deviations were calculated and results were analyzed by ANOVA. There were significant differences (P < 0.001) in the polyphenol and tannin contents of cultivars of the same pulse, with the exception of the tannin contents of pressure-cooked red gram cultivars (P = 0.3103). Processing reduced the concentrations of polyphenols by 19–59% and of tannins by 22–59%. A trend was observed in the degree to which processing reduced polyphenol and tannin contents (germination > pressure-cooking > soaking). Soaking, germination and pressure-cooking proved to be effective household strategies to reduce the levels of polyphenols and tannins in pulse-based foods, thereby enhancing the bioavailability of pulse protein. There is a need to determine the extent to which the remaining polyphenols and tannins are rendered unavailable by these processing techniques.