Investigation of folate composition and influence of processing on folate stability in pulse accessions developed in China.

Pulses are good natural sources of micronutrients. In this study, the concentration and composition of folates in seeds of 102 pulse varieties newly-developed in China, including mung beans, adzuki beans, cowpeas, faba beans, peas, and common beans, were analysed. The total folate content ranged from 21 to 278 μg/100 g dry weight (DW) among these pulse crops, with the highest in faba beans (88–278 μg/100 g DW), followed by cowpeas (101–246 μg/100 g DW), and the lowest in common beans (21–66 μg/100 g DW). 5-Formyltetrahydrofolate and 5-methyltetrahydrofolate were the two dominant folate vitamers. In addition, the effect of soaking (30 °C for 12 h) and boiling (100 °C for 20 min) on folate retention in pulses was evaluated. Compared to the unprocessed pulses, a 1.41-fold (average) enhancement of total folates was observed in soaked pulses. Folate retention ratios in boiled pulses depended on varieties, ranging from 64% to 82%, with the average of 76%. During the boiling process, 13% of total folates was lost through leaching and 29% by heating degradation on average. This research provides an overview of folate content and retention in raw and cooked pulses. The results will help to guide industrial or household preparation of pulses to maximise folate retention and the identified pulse varieties rich in folates could be for direct use or as breeding materials for folate biofortification. • The folate contents of 102 pulses were analysed; total folates ranged from 21 to 278 μg/100 g DW. • Faba bean and cowpea were good sources of folates. • The dominant folate vitamers in pulses were 5-CHO-THF and 5-CH 3 -THF. • Soaking at 30 °C for 12 h increased the folate content 1.41-fold on average. • On average, boiled pulses had a folate retention rate of 76%. [ABSTRACT FROM AUTHOR]