**6. Folate in germinated cereals**

The effects of germination and subsequent oven-drying or freeze-drying on folate content in a number of wheat and rye cultivars were studied for producing folate-rich flour ingredients. As reported in previous studies [41–43], germination of wheat and rye resulted in a four- to sixfold higher folate content than untreated cereals, mainly due to an increase in 5-CH3-H4 folate (w4-fold). The increased folate content has been attributed to de novo synthesis of folate being accelerated because of increased demand for methyl groups (one carbon unit) during germination [43]. Oven-drying (50°C) did not significantly affect the folate content, which is in agreement with our previous findings that oven-drying of germinated grains is suitable for the production of folate-rich candidate ingredients [44]*.* It has recently reported that by addition of germinated wheat flour to native wheat flour, bread with a 65% higher folate content compared with conventional Egyptian baladi bread could be prepared [45]. Germinated cereal grains and flour could also serve as functional ingredients for the European bread-baking industry. Here, the folate content in the rye cultivars studied was approximately 25% higher than that in the wheat cultivars. This confirms findings by [46] that rye flour contains more folate than flour from other cereals such as wheat, triticale, barley, and oats. The folate content quantified in the four Swedish wheat cultivars tested (23–33 mg/100 g dry matter DM) is also similar to HPLC data (34–40 mg/100 g DM) reported for four Polish wheat cultivars [48]. In comparison to data from microbiological assays [47–49], the mean folate content in untreated wheat and rye cultivars was 30–40% lower in this study. HPLC methods generally tend to provide folate values which are around

30% lower than data from microbiological assays [46–48]. Furthermore, the sum of folate content was underestimated by lack of quantification of 5-HCO-H4 folate and 10-formyl-dihydrofolate. Other groups also reported difficulties in quantification of 5-HCO-H4 folate in cereal foods using HPLC [45–47]. Up to 40% 5-HCO-H4 folate was reported in untreated wheat and rye [45–48], and the content was not significantly affected by germination of rye [49]. Also 7–13% of 10-formyl-dihydrofolate was found in untreated and germinated rye cultivars by [49, 50], while [51] did not detect this form. This can partly explain the discrepancy between our results and data reported in the literature. The mean folate content in six rye and four wheat cultivars ranges from 23 to 39 mg/100 g DM, being approximately 25% higher in rye than in wheat. The folate content in both cereals by four- to sixfold increases in germination subsequent oven-drying, which is required for milling of germinated grains, does not affect the folate content. Germinated kernels and their flours are ingredients with increased folate content for use in bakery products [52].
