Nutritional properties of tempe fermented whole-grain barley and oats. Influence of processing conditions on the retention and availability of iron, starch and folates.

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 f-glucan barley and high f-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

Whole-grain cereal products based on a high-fibre barley or oat genotype lower post-prandial glucose and insulin responses in healthy humans

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 ß-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-ß-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

Starch microstructure and starch hydrolysis in barley and oat tempe during in vitro digestion

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 \ub1 33) was 40 % of the AUC for oat tempe (663 \ub1 8) and significantly different (

Starch Microstructure and Starch Hydrolysis in Barley and Oat Tempe During In Vitro Digestion.

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 \ub1 33) was 40 % of the AUC for oat tempe (663 \ub1 8) and significantly different (

Tempe Fermentation of Whole Grain Barley Increased Human Iron Absorption and In vitro Iron Availability

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

Rhizopus oligosporus and yeast co-cultivation during barley tempeh fermentation-Nutritional impact and real-time PCR quantification of fungal growth dynamics

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 B-6 and niacinamide, and slight decreases of B, 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

The Nordic Maintenance Care Program: Does psychological profile modify the treatment effect of a preventive manual therapy intervention? A secondary analysis of a pragmatic randomized controlled trial.

BackgroundChiropractic maintenance care is effective as secondary/tertiary prevention of non-specific low back pain (LBP), but the potential effect moderation by psychological characteristics is unknown. The objective was to investigate whether patients in specific psychological sub-groups had different responses to MC with regard to the total number of days with bothersome pain and the number of treatments.MethodData from a two-arm randomized pragmatic multicenter trial with a 12-month follow up, designed to investigate the effectiveness of maintenance care, was used. Consecutive patients, 18-65 years of age, with recurrent and persistent LBP seeking chiropractic care with a good effect of the initial treatment were included. Eligible subjects were randomized to either maintenance care (prescheduled care) or to the control intervention, symptom-guided care. The primary outcome of the trial was the total number of days with bothersome LBP collected weekly for 12 months using an automated SMS system. Data used to classify patients according to psychological subgroups defined by the West Haven-Yale Multidimensional Pain Inventory (adaptive copers, interpersonally distressed and dysfunctional) were collected at the screening visit.ResultsA total of 252 subjects were analyzed using a generalized estimating equations linear regression framework. Patients in the dysfunctional subgroup who received maintenance care reported fewer days with pain (-30.0; 95% CI: -36.6, -23.4) and equal number of treatments compared to the control intervention. In the adaptive coper subgroup, patients who received maintenance care reported more days with pain (10.7; 95% CI: 4.0, 17.5) and more treatments (3.9; 95% CI: 3.5, 4.2). Patients in the interpersonally distressed subgroup reported equal number of days with pain (-0.3; 95% CI: -8.7, 8.1) and more treatments (1.5; 95% CI: 0.9, 2.1) on maintenance care.ConclusionsPsychological and behavioral characteristics modify the effect of MC and should be considered when recommending long-term preventive management of patients with recurrent and persistent LBP