| 1. |
- Alminger, Marie, 1957, et al.
(författare)
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Whole-grain cereal products based on a high-fibre barley or oat genotype lower post-prandial glucose and insulin responses in healthy humans
- 2008
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Ingår i: European Journal of Nutrition. - : Springer Science and Business Media LLC. - 1436-6207 .- 1436-6215. ; 47:6, s. 294-300
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Tidskriftsartikel (refereegranskat)abstract
- Background: Several factors can affect glycemic and insulinemic responses from cereal foods. Some suggested factors lowering the responses are; intact botanical structure, high amylose/high β-glucan cereal varieties, organic acid produced during fermentation and food processes inducing retrogradation of starch. Aim of the study: To evaluate the impact of fermented whole grain cereal kernels with high content of amylose (40%) and/or β-glucan (4.6%) on postprandial glucose and insulin responses in healthy adults. Methods: Thirteen healthy volunteers (4 men and 9 women) were given 25 g available carbohydrate portions of: glucose solution; tempe fermented whole-grain barley and tempe fermented whole-grain oat. Blood samples were collected directly before the meal (fasting) and 15, 30, 45, 60, 90 and 120 min after the start of the meal. The GI (glycemic index) and II (insulin index) of meals were calculated for each subject according to FAO/WHO standards. Results: Peak glucose response was lowest after the tempe meal with high-amylose/ high-β-glucan barley tempe while insulin response was lowest after the meal with high β-glucan oat tempe. The mean blood glucose responses for both the barley and the oat tempe meals were significantly lower than from the reference glucose load (P < 0.0001) during the first 60 min. The calculated GI:s for barley and oat tempe were 30 and 63, respectively. Mean serum insulin responses from barley and oat tempe were significantly lower compared with the glucose load (P < 0.002) during the first 60 min, and the calculated II was lower for oat tempe (21) compared with barley tempe (55). Conclusions: The results suggest that cereal products with beneficial influence on postprandial plasma glucose and insulin responses can be tailored by fermentation and enclosure of high-amylose and/or high-β-glucan barley and oat kernels. © 2008 Spinger.
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| 2. |
- Eklund Jonsson, Charlotte, 1964
(författare)
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Nutritional properties of tempe fermented whole-grain barley and oats. Influence of processing conditions on the retention and availability of iron, starch and folates.
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aimed at evaluating the tempe fermentation process as a means to develop nutritionally improved vegetarian products from barley and oats. The work was designed to assess relationships between selection of raw material and processing conditions in correlation to nutrient content and availability. Whole grains of high amylose/high ß-glucan barley and high ß-glucan oats were tempe fermented with Rhizopus oligosporus, in order to: reduce phytate content to increase iron absorption, obtain low glycemic responses, and increase formation and accessibility of folates. The barley and oat tempe were evaluated in human studies. Corresponding meals were also in vitro digested in order to evaluate the potential of estimating human nutrient bioavailability in a computer controlled gastrointestinal model.Pearling, soaking and returning of pearling fractions before tempe fermentation was found to degrade the phytate content by 97% and to increase human iron absorption from 3.0% to 5.5%. In vitro digestion of similar meals showed an increase in iron availability from 1.7% to 4.9%, indicating that the tendency of the iron absorption could be predicted. The glucose response was lower from the barley tempe while the insulin response was lowest after intake of oat tempe. The calculated glycemic and insulinemic indices (GI and II) were 30 and 55 from barley tempe and 63 and 21 from oat tempe, respectively. In vitro starch digestion rate of barley and oat tempe meals were consistent with the human glycemic response, and by combining the determination of in vitro starch hydrolysis with microscopy studies of starch granules, a possible correlation between structural changes during digestion and the rate of starch hydrolysis was observed. Furthermore, tempe fermentation of barley increased folate content by 2.5 times, and the in vitro folate accessibility was 46-86% in boiled barley tempe. This work shows the nutritional potential of tempe fermented whole-grain cereal products with a range of health benefits, such aslow glycemic responses and high availability of iron and folate. The work also shows that the in vitro gastrointestinal model is a possible tool to estimate the availability of important nutrients.
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| 3. |
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| 4. |
- Eklund-Jonsson, Charlotte, et al.
(författare)
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Reduction of phytate content while preserving minerals during whole grain cereal tempe fermentation
- 2006
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Ingår i: Journal of Cereal Science. - : Elsevier BV. - 0733-5210 .- 1095-9963. ; 44:2, s. 154-160
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Tidskriftsartikel (refereegranskat)abstract
- The effects of different pretreatments on phytate and mineral contents were investigated in whole grain barley and oat tempe fermented with Rhizopus oligosporus. Different varieties of barley and oats were exposed to pretreatments such as pearling, rolling, moistening, autoclaving and soaking before fermentation. Pearling was the most effective pretreatment for reduction of phytate content for both oats and barley. Nevertheless, mineral contents were reduced, and most likely cell wall rich fractions were also reduced by this process. In the first experiments the phytate content reduction in the oats and barley samples were reduced by 74% (3.3 μmol/g, d.m.) and 89% (1.4 μmol/g, d.m.), respectively. However, to improve iron absorption the phytate levels should not exceed 0.5 μmol/g, and further phytate degradation was necessary. Therefore, in the final experiments barley samples were exposed to an optimised process with prolonged soaking at a higher temperature and the pearling residues were returned before fermentation. When the outer layers of the barley kernels were returned before fermentation the phytate content was successfully reduced by 97% to 0.4 μmol/g (d.m.) and Fe and Zn levels were well preserved. © 2006.
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| 5. |
- Eklund Jonsson, Charlotte, 1964, et al.
(författare)
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Tempe Fermentation of Whole Grain Barley Increased Human Iron Absorption and In vitro Iron Availability
- 2008
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Ingår i: The Open Nutrition Journal. - : Bentham Science Publishers Ltd.. - 1874-2882. ; 2, s. 42-47
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, iron absorption from a tempe fermented whole-grain barley meal was measured, and results were compared to in vitro estimation of available iron from an equivalent meal. The tempe meal (TM) was prepared from barley fermented with Rhizopus oligosporus to reduce the phytate content <0.5 µmol/g, and boiled barley with preserved phytate content was used as reference meal (BBM). Iron was added to obtain a total content of 3 mg/meal in the human study, and to the in vitro meals 7 mg of iron was added. The iron absorption from TM and BBM was 5.5±1.5% and 3.0±0.7% respectively, and in vitro iron availability was 4.9±0.2% in TM and 1.7±0.1% in BBM (absorbed fraction of total iron/meal). To conclude, iron absorption from a barley meal was improved by reducing the phytate content via tempe fermentation, and iron absorption was predicted by direction in the in vitro experiments.
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| 6. |
- Feng, X. M., et al.
(författare)
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Rhizopus oligosporus and yeast co-cultivation during barley tempeh fermentation-Nutritional impact and real-time PCR quantification of fungal growth dynamics
- 2007
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Ingår i: Food microbiology (Print). - London, United Kingdom : Elsevier BV. - 0740-0020 .- 1095-9998. ; 24:4, s. 393-402
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Tidskriftsartikel (refereegranskat)abstract
- Barley tempeh was produced by fermenting barley kernels with Rhizopus oligosporus. The potential of the yeasts Saccharomyces cerevisiae (three strains), S. boulardii (one strain), Pichia anomala (one strain) and Kluyveromyces lactis (one strain) to grow together with R. oligosporus during barley tempeh fermentation was evaluated. All yeast strains grew during the fermentation and even during cold storage of tempeh (P < 0.01). The growth of yeasts slightly increased the ergosterol contents, but did not influence amino acid contents and compositions, and did not reduce phytate contents. Slight increases of vitamins B6 and niacinamide, and slight decreases of B1 and biotin were observed. Quantification of fungal growth is difficult during mixed species fermentations because ergosterol is found in all fungal species, and colony-forming-unit (cfu) estimations are not reliable for R. oligosporus and other sporulating fungi. Therefore, we developed a quantitative real-time PCR method for individually quantifying S. cerevisiae and R. oligosporus growth in barley tempeh. The PCR results were highly correlated with the ergosterol content of R. oligosporus and with the number of cfu of S. cerevisiae. Thus, real-time PCR is a rapid and selective method to quantify yeasts and R. oligosporus during mixed species fermentation of inhomogenous substrate such as barley tempeh. © 2006 Elsevier Ltd. All rights reserved.
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| 7. |
- Larsson Alminger, Marie, 1957, et al.
(författare)
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Starch microstructure and starch hydrolysis in barley and oat tempe during in vitro digestion
- 2012
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Ingår i: Food Digestion. - : Springer Science and Business Media LLC. - 1869-1986 .- 1869-1978. ; 3:1-3, s. 53-62
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Tidskriftsartikel (refereegranskat)abstract
- Various botanical and structural characteristics of starchy foods are considered to modify the rate of starch digestion and the glycaemic responses in humans. The main objective of the study was to examine the impact of fermented barley and oat microstructure on the rate of in vitro starch hydrolysis. A dynamic gastrointestinal model was used to estimate the degree of starch hydrolysis during in vitro digestion of fermented whole grain cereal meals. Light microscopy and confocal laser scanning microscopy were used to study the microstructural changes. In parallel to the in vitro studies, the impact of fermented barley and oats on postprandial plasma glucose responses was evaluated in a human study. Micrographs were taken during in vitro digestion experiments with fermented whole grains and compared with micrographs of boiled barley (undigested). Images showed that most of the oat starch granules were degraded after 120 min of digestion, whereas barley starch granules were less degraded, even after 180 min of digestion. The findings were confirmed by faster starch hydrolysis from the fermented oat meal, measured as maltose generated during in vitro digestion. The area under the curve (AUC) was calculated from the plotted maltose curves of the meals. AUC for barley tempe (266 ± 33) was 40 % of the AUC for oat tempe (663 ± 8) and significantly different (p
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| 8. |
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| 9. |
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| 10. |
- Salovaara, S., et al.
(författare)
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Prolonged transit time through the stomach and small intestine improves iron dialyzability and uptake in vitro
- 2003
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 51:17, s. 5131-5136
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Tidskriftsartikel (refereegranskat)abstract
- The iron dialyzability and uptake in relation to transit time through the stomach and small intestine was investigated using a dynamic in vitro gastrointestinal model in combination with Caco-2 cells. Three test meals were evaluated, consisting of lactic fermented vegetables with white (I) or whole meal bread (II) and of sourdough-fermented rye bread (III). Three transit times were tested (fast, medium, and slow transport). Iron dialyzability and absorption differed significantly between medium and slow transit time for meal I and between fast and medium transit time for meal III. For meal II, high in phytate, the iron dialyzability and absorption were low irrespective of transit time. The meals could be ranked with respect to iron dialyzability and uptake in the order I > III > II. Although the in vitro models used have limitations compared to in vivo experiments, the results suggest that an increased transit time may improve iron availability.
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