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Susanna Kariluoto

Publications and source records attributed to Susanna Kariluoto.

5 recordsLinked to original sources
PubMed2006

Effect of germination and thermal treatments on folates in rye.

Effects of germination conditions and thermal processes on folate contents of rye were investigated. Total folate contents were determined microbiologically with Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism, and individual folates were determined by high-performance liquid chromatography after affinity chromatographic purification. Germination increased the folate content by 1.7-3.8-fold, depending on germination temperature, with a maximum content of 250 micro g/100 g dry matter. Hypocotylar roots with their notably high folate concentrations (600-1180 micro g/100 g dry matter) contributed 30-50% of the folate contents of germinated grains. Germination altered the proportions of folates, increasing the proportion of 5-methyltetrahydrofolate and decreasing the proportion of formylated folate compounds. Thermal treatments (extrusion, autoclaving and puffing, and IR and toasting) resulted in significant folate losses. However, folate levels in grains that were germinated and then were heat processed were higher than for native (nongerminated) grains. Opportunities to optimize rye processing to enhance folate levels in rye-based foods are discussed.

Folic Acid↗
PubMed2005

Effects of yeasts and bacteria on the levels of folates in rye sourdoughs.

Fermentation of rye dough is often accompanied with an increase in folate content. In this study, three sourdough yeasts, Candida milleri CBS 8195, Saccharomyces cerevisiae TS 146, and Torulaspora delbrueckii TS 207; a control, baker's yeast S. cerevisiae ALKO 743; and four Lactobacillus spp., L. acidophilus TSB 262, L. brevis TSB 307, L. plantarum TSB 304, and L. sanfranciscensis TSB 299 originally isolated from rye sourdough were examined for their abilities to produce or consume folates. The microorganisms were grown in yeast extract-peptone-d-glucose medium as well as in small-scale fermentations that modelled the sourdough fermentation step used in rye baking. Total folate contents were determined using Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism. The microorganisms studied did not excrete folates into the media in significant amounts. Yeasts increased the folate contents of sterilised rye flour-water mixtures from 6.5 microg/100 g to between 15 and 23 microg/100 g after 19-h fermentation, whereas lactic acid bacteria decreased it to between 2.9 and 4.2 microg/100 g. Strains of Lactobacillus bulgaricus, L. casei, L. curvatus, L. fermentum, L. helveticus, Pediococcus spp., and Streptococcus thermophilus that were also tested gave folate contents after fermentation that varied between 2 and 10.4 microg/100 g. Although the four Lactobacillus spp. from sourdough consumed folates their effect on folate contents in co-cultivations was minimal. It was concluded that the increase of folate content during fermentation was mainly due to folate synthesis by yeasts. Fermentation of non-sterilised flour-water mixtures as such resulted in three-fold increases in the folate contents. Two folate producing bacteria were isolated from the non-sterilised flour and identified as Enterobacter cowanii and Pantoea agglomerans.

Bread↗
PubMed2003

Process-induced changes on bioactive compounds in whole grain rye.

Manufacturing of healthy wholegrain foods demands knowledge of process-induced changes in macro-, micro- and non-nutrients. The high content of dietary fibre is a challenge in relation to good product texture and sensory quality. The stability and bioavailability of bioactive compounds have a marked influence on the health effects of cereal foods. It was confirmed that sterols, folates, tocopherols and tocotrienols, alkylresorcinols, lignans, phenolic acids and total phenolics are concentrated in the bran layers of the rye grain, and are only present at low levels in the flour endosperm. The levels of folate and easily-extractable phenolic compounds increase in germination and sourdough baking, but there are negligible changes in the levels of sterols, lignans and alk(en)ylresorcinols. The levels of tocopherols and tocotrienols are reduced during the sourdough fermentation. In conclusion, many of the bioactive compounds in wholegrain rye are stable during food processing, and their levels can even be increased with suitable processing.

Dietary Fiber↗
PubMed2002

Functionality of endogenous folates from rye and orange juice using human in vivo model.

BACKGROUND: Cereals contribute about a quarter of the daily folate intake from a typical diet in several European countries. However, studies on bioavailability of endogenous folates, in particular of cereal sources, are scarce. AIM OF THE STUDY: We aimed to study how well natural folates from rye (different rye breads and muesli made of malted rye) and orange juice function in improving folate status of human volunteers compared to a diet containing folic acid fortified wheat bread. METHODS: Healthy human volunteers aged 20-66 y took part in a four-week intervention trial in which bread, breakfast cereal and juice were provided. The study had a parallel design with two groups, 1) rye and orange juice group (33 volunteers) and 2) fortified wheat bread and apple juice group (31 volunteers). The test foods provided on average 184 microg and 188 microg folate per day in rye and wheat groups, respectively. Test foods were consumed as part of the subjects' normal diet. RESULTS: In both groups statistically significant increases in serum and red cell folates were observed after the intervention period. The serum folate increased 26 % and 31 %, and red cell folate levels increased 17 % and 15 % in rye and orange juice and wheat and apple juice groups, respectively. The effects did not differ between the rye and wheat groups. Increases in serum and red cell folate were more profound among subjects with low starting folate levels. Decrease in the plasma homocysteine concentrations was observed only in the highest tertile of both groups but not in the group means. CONCLUSIONS: Endogenous folates incorporated into a healthy diet, even in moderate amounts, is an efficient way to improve folate status among healthy adults. Folates from different rye products and orange juice showed good bioavailability that was similar to folic acid from fortified white bread.

Adult↗