Can bread processing conditions alter glycaemic response?

Effects of coarse cereals on dough and Chinese steamed bread - a review

Chinese steamed breads (CSBs) are long-established staple foods in China. To enhance the nutritional value, coarse cereals such as oats, buckwheat, and quinoa have been added to the formulation for making CSBs. This review presents the nutritional value of various coarse cereals and analyses the interactions between the functional components of coarse cereals in the dough. The addition of coarse cereals leads to changes in the rheological, fermentation, and pasting aging properties of the dough, which further deteriorates the appearance and texture of CSBs. This review can provide some suggestions and guidelines for the production of staple and nutritious staple foods.

Oral and gastrointestinal nutrient bioaccessibility of gluten-free bread is slightly affected by deficient mastication in the elderly

The main goal of this work was to investigate the impact of impaired mastication on nutrient bioaccessibility of gluten-free bread in the elderly. In vitro boluses were produced with the AM² masticator by using two types of programming: normal mastication (NM) and deficient mastication (DM). Static in vitro gastrointestinal digestion was performed with the digestive physiology conditions of the elderly. Subsequently, the granulometric properties of the in vitro boluses produced, their starch and protein digestibility, and lipid peroxidation after in vitro oral and gastrointestinal digestion were evaluated. DM boluses presented higher proportions of large particles, resulting in insufficiently fragmented boluses. A delay in oral starch digestion was observed in DM boluses, probably due to the presence of larger particles that limited the bolus-saliva exchanges. Furthermore, DM boluses exhibited a lower degree of protein hydrolysis at the end of gastric digestion, whereas no differences were observed for protein hydrolysis, sugar release, and lipid peroxidation at the end of digestion (intestinal phase). The results of this study show that impaired mastication somewhat delays the nutrient bioaccessibility of the gluten-free bread tested. Such understanding of the effect of oral decline on the nutrient bioaccessibility of foods is crucial when designing food commodities with enhanced functionalities for the elderly.

Wakame replacement alters the metabolic profile of wheat noodles after in vitro digestion

The development of nutritional noodles of high quality has become a new hotspot of research in the area of food science. Since wakame is edible seaweed rich in dietary fiber and proteins and rarely found in ordinary noodle, this study investigated the release of metabolites, the texture quality, and the rheological properties of wakame noodle, as well as the mechanism by which extruded wakame flours can influence noodle texture and viscoelasticity through digestion. Basically, nuclear magnetic resonance spectra were applied to identify the 46 metabolites including amino acids, saccharides, fatty acids, and other metabolites. Both PCA and OPLS-DA model showed fit goodness and good predictivity, which were assessed the increasing release of most metabolites. Structural studies discussed the effects on the enhancement of interlinkage with gluten matrix and protein matrix, which were validated via the decreasing instantaneous compliance J0 (1.64 × 10-5 to 0.16 × 10-5 Pa-1). Wakame addition best matched the physiochemical properties of noodle, in terms of chewiness (99.10 vs 122.66 g.mm), gumminess (281.98 vs. 323.44 g), and gel strength (132.65 vs 173.95 kPa•s-1). Beyond the functional characteristics it contributes benefits like reduction of diet-related diabetes. As a consequence, the creation of personalized nutritious, healthy noodles will be an innovative route from a scientific viewpoint and an application standpoint.

Bioaccessibility and Bioavailability of (-)-Epigallocatechin Gallate in the Bread Matrix with Glycemic Reduction

Bread has a high glycemic index (GI) and rich contents of quickly digestible carbohydrates, which is associated with insulin resistance and the risk of chronic diseases. (-)-Epigallocatechin Gallate (EGCG) is the primary catechin component that inhibits starch hydrolases, while the low release and absorption rates limit its utilization. In this study, EGCG was added to the bread matrix for fortification to reduce its glycemic index compared to white bread. EGCG fortification at 4% decreased the starch digestion rate of baked bread by 24.43% compared to unfortified bread and by 14.31% compared to white bread, with an identical amount of EGCG outside the matrix. Moreover, the predicted GI (pGI) was reduced by 13.17% compared to white bread. Further, 4% EGCG-matched bread enhanced the bioaccessibility and bioavailability of EGCG by 40.38% and 47.11%, respectively, compared to the control. The results of molecular docking demonstrated that EGCG had a higher binding affinity with α-amylase than with α-glucosidase, indicating that EGCG may effectively inhibit the accumulation of carbs during starch digestion. Thus, EGCG can be used as a functional ingredient in bread to reduce its glycemic potential, and the bread matrix can be used as a carrier for EGCG delivery to enhance its bioaccessibility and bioavailability.

The influence of dough kneading time and flour particle size distribution on white bread structure, glycemic response and aspects of appetite

BACKGROUND & AIMS

White bread is widely consumed in many countries despite being a high-glycemic index (GI) food. It has been shown that the "food matrix effect" may help with diabetes and obesity management through lowering GI and appetite. This study aimed at investigating the effects of dough kneading time and flour particle size on white bread structure, glycemic response, and aspects of appetite.

METHODS

A two-phase randomized cross-over design was used in 10 healthy subjects over the course of 2 h. In phase 1, Texture Profile Analysis (TPA) attributes, Scanning Electron Microscope (SEM) image, glycemic response, and appetite aspects of white bread made with a 15-min dough kneading time (K15) were compared with white bread made with a 10-min dough kneading time (K10). In phase 2, TPA, SEM image, glycemic response, and satiety score of white bread made with coarse flour (CF) were compared to white bread made with fine flour (FF).

RESULT

With increasing hardness (force required to compress a food between the molars to a given deformation), total blood glucose IAUC in K15 (IAUC = 119 ± 12; GI = 66) was significantly (p < 0.05) lower than in K10 (IAUC = 154 ± 10; GI = 81). No marked difference was observed between K15 and K10 on aspects of appetite except for hunger. There was no significant (p > 0.05) difference in glycemic response between CF (IAUC = 126 ± 18; GI = 64) and FF (IAUC = 147 ± 12; GI = 81). Similarly, no discernible difference in satiety between CF and FF.

CONCLUSION

Changes in processing conditions can improve blood glucose response relalated to white bread consumption.

Main factors affecting the starch digestibility in Chinese steamed bread

Chinese steamed bread (CSB) is one of the staple foods in China, although it has a high glycemic index (GI) value. Development of CSB with a slower starch digestibility is thus of great importance for the improvement of human health. Many factors are related to the starch digestibility in CSB. Most currently available strategies are focusing on the incorporation of other whole flours with high dietary fiber or polyphenols to reduce the starch digestibility. Although successful in reducing starch digestibility, the incorporation of these flours also deteriorated textural attributes and sensory characteristics of CSB. Much more strategies have been applied for the reduction of starch digestibility in breads, which should be further explored to confirm if they are applicable for CSB. This review contains important information, that could potentially turn CSB into a much healthier food product with slower starch digestibility.

Protein Ingredients in Bread: Technological, Textural and Health Implications

The current lifestyle and trend for healthier foods has generated a growing consumer interest in acquiring bread products with a better nutritional composition, primarily products with high protein and fiber and low fat. Incorporating different protein sources as functional ingredients has improved the nutritional profile but may also affect the dough properties and final characteristics of bread. This review focuses on the incorporation of different animal, vegetable, and mixed protein sources, and the percentage of protein addition, analyzing nutritional changes and their impact on dough properties and different texture parameters, appearances, and their impact on bread flavor and health-related effects. Alternative processing technologies such as germination and sourdough-based technologies are discussed. Using fermented doughs can improve the nutritional composition and properties of the dough, impacting positively the texture, appearance, flavor, and aroma of bread. It is essential to innovate alternative protein sources in combination with technological strategies that allow better incorporation of these ingredients, not only to improve the nutritional profile but also to maintain the texture and enhance the sensory properties of the bread and consequently, increase the effects on consumer health.

Influence of oral processing behaviour and bolus properties of brown rice and chickpeas on in vitro starch digestion and postprandial glycaemic response

PURPOSE

Oral processing behaviour may contribute to individual differences in glycaemic response to foods, especially in plant tissue where chewing behaviour can modulate release of starch from the cellular matrix. The aim of this study was to assess the impact of chewing time of two starch based foods (brown rice and chickpeas) on bolus properties, in vitro starch digestion and postprandial glycaemic excursion in healthy subjects.

METHODS

In a cross-over trial participants (n = 26) consumed two carbohydrates-identical test meals (brown rice: 233 g; chickpeas: 323 g) with either long (brown rice: 41 s/bite; chickpeas: 37 s/bite) or short (brown rice: 23 s/bite; chickpeas: 20 s/bite) chewing time in duplicate while glycaemic responses were monitored using a continuous glucose monitoring device. Expectorated boli were collected, then bolus properties (number, mean area, saliva amylase activity) and in vitro starch digestion were determined.

RESULTS

Longer chewing resulted in significantly (p < 0.05) more and smaller bolus particles, higher bolus saliva uptake and higher in vitro degree of intestinal starch hydrolysis (DH_S_{chewing time}%) than shorter chewing for both foods (brown rice: DH_S%_23 s = 84 ± 4% and DH_%S_41s = 90 ± 6%; chickpeas: DH_S%_20 s = 27 ± 3% and DH_%S_37s = 34 ± 5%, p < 0.001). No significant effect of chewing time on glycaemic response (iAUC) (p > 0.05) was found for both meals. Brown rice showed significantly and considerably higher in vitro degree of intestinal starch hydrolysis and glycaemic response (iAUC) than chickpeas regardless of chewing time. No significant correlations were observed between bolus properties and in vitro starch hydrolysis or glycaemic response (p > 0.05).

CONCLUSION

Differences in the innate structure of starch based foods (brown rice compared to chickpeas) have a larger effect on postprandial glucose response than differences in mastication behaviour although oral processing behaviour showed consistent effects on bolus properties and in vitro starch digestion. Trial registration ClinicalTrials.gov identifier: NCT04648397 (First posted: December 1, 2020).

Enhancing health benefits of bakery products using phytochemicals

There has been a growing interest in functional bakery products with enhanced health benefits, especially the prevention of some chronic diseases such as type 2 diabetes, cardiovascular diseases and neurodegenerative disorders. Fortification of wheat flour with phytochemicals, plant components with various bio-activities, is one of the promising approaches to improving public health with the ubiquitous consumption of baked goods. This chapter reviews the current knowledge of several representative phytochemicals, mainly plant polyphenols, including catechins, anthocyanins, fucoidan and quercetin extracted from various plant resources, and their application in bakery products, regarding their stability, impact on product quality and potential health benefits.

How Different Are Industrial, Artisanal and Homemade Soft Breads?

Soft bread has a significant relevance in modern diets, and its nutritional impact on human health can be substantial. Within this product category, there is an extensive range of ingredients, formulations, and processing methods, which all contribute to the vast diversity found in the final products. This work compared the impact of three different processing methods (industrial, artisanal, and homemade preparation) on the technological (formulation and processing, as they are interconnected in real-life conditions), nutritional, and physicochemical properties of soft bread. In total, 24 types of soft bread were analyzed: 10 industrial, 6 artisanal, and 8 homemade. Although production diagrams were similar among the three methods, industrial recipes contained on average more ingredients and more additives. Industrial bread was lower in saturated fat compared to the other two groups, but contained more sugar than homemade bread. The physical properties of all loaves were comparable, with the exception of higher crumb elasticity in industrial bread compared to homemade. An analysis of volatile molecules revealed more lipid oxidation markers in industrial bread, more fermentation markers in artisanal bread, and fewer markers of Maillard reactions in homemade bread. Chemical reactions during processing seem to be the principal criterion making possible to discriminate the different processing methods. These results offer a quantitative assessment of the differences within a single product category, reflecting the real-world choices for consumers.

Effects of high-amylose maize starch on the glycemic index of Chinese steamed buns (CSB)

The incorporation of resistant starch (RS) in food has gained importance to be a good replacement for digestible carbohydrate. This study examined the effect of compositing RS (high-amylose maize starch (HM)) as wheat flour substitute (30%) in Chinese steamed bun (CSB) formulation on postprandial glycemic response in healthy human subject. In this single-blind and cross-over experimental trial, a total of 15 female participants (mean age = 31.5 ± 3.9) were randomly assigned to receive CSB containing 30% HM (HM30) or control CSB (without HM) with their blood glucose were recorded throughout the test. The blood glucose concentrations recorded for HM30 were significantly lower than control CSB at 15 min (6.03 vs. 7.04 mmol/L, p = 0.041), 30 min (6.93 vs. 7.76 mmol/L, p = 0.021), 45 min (6.21 vs. 7.55 mmol/L, p = 0.032), 60 min (5.68 vs. 6.26 mmol/L, p = 0.038), and 90 min (5.08 vs. 5.73 mmol/L, p = 0.022). The 2-h postprandial glucose was significantly lower in HM30 (iAUC = 105.2 mmol x min/L) than the control (186.1 mmol x min/L). The low GI property of HM30 (GI = 39.11 ± 5.6) did not cause sudden rapid increase in blood glucose concentration as observed in medium-GI control CSB (GI = 69.18 ± 9.8). This study suggests that adding 30g of HM decreased the glycemic index of CSB in healthy female adult.

Assessment of the glycaemic index, content of bioactive compounds, and their in vitro bioaccessibility in oat-buckwheat breads

This study addressed determinations of the glycaemic index (GI), antioxidant capacity (AC), and phenolics content (TPC) of oat, buckwheat, and mixed oat/buckwheat breads. The bioaccessibility of TPC and the AC of breads were studied after in vitro digestion. The lowest values of the GI were determined for oat bread, whereas breads with the highest content of buckwheat flour had the highest AC. The digestion of breads showed that most of the TPC were found in the soluble fraction, but the phenolic compounds were still present also in the insoluble fraction after digestion. It was concluded that the mixed oat-buckwheat breads may serve as products with a medium GI, as a source of TPC, and as products with a high AC. It should be noted that enzymatic digestion or fermentation by microbiota could potentially enhanced breads antioxidant activity during digestion in the gastrointestinal tract.

Wholegrain Particle Size Influences Postprandial Glycemia in Type 2 Diabetes: A Randomized Crossover Study Comparing Four Wholegrain Breads

OBJECTIVE

Wholegrain foods vary in the extent of processing. We investigated whether wholegrain particle size in bread influences postprandial glycemia in type 2 diabetes.

RESEARCH DESIGN AND METHODS

Postprandial glycemia (incremental area under the blood glucose curve [iAUC]) was measured after consumption of three breads made with roller-milled wholegrain flour and added grains and a fourth made with stone-ground flour. All flours and grains were 100% wholegrain wheat. Breads were nutrient matched.

RESULTS

Fifteen adults (64 ± 10 years, HbA_1c 58 ± 13 mmol/mol) completed the study. iAUC for the three breads made with roller-milled flour ranged from 376 to 641 mmol^-1min^-1, inverse linear trend for grain particle size P = 0.039. The iAUC for stone-ground wholegrain bread (503) was smaller than predicted from mean particle size.

CONCLUSIONS

Wholegrain structural integrity in bread is a determinant of glycemic response. These findings have implications for dietary advice and the definition of the term "'wholegrain."

Reducing the glycemic impact of carbohydrates on foods and meals: Strategies for the food industry and consumers with special focus on Asia

Type 2 diabetes is increasingly prevalent in Asia, which can be attributed to a carbohydrate-rich diet, consisting of foods in the form of grains, for example, rice, or a food product made from flours or isolated starch, for example, noodles. Carbohydrates become a health issue when they are digested and absorbed rapidly (high glycemic index), and more so when they are consumed in large quantities (high glycemic load). The principal strategies of glycemic control should thus aim to reduce the amount of carbohydrate available for digestion, reduce the rate of digestion of the food, reduce the rate of glucose absorption, and increase the rate of glucose removal from blood. From a food perspective, the composition and structure of the food can be modified to reduce the amount of carbohydrates or alter starch digestibility and glucose absorption rates via using different food ingredients and processing methods. From a human perspective, eating behavior and food choices surrounding a meal can also affect glycemic response. This review therefore identifies actionable strategies and opportunities across foods and meals that can be considered by food manufacturers or consumers. They are (a) using alternative ingredients, (b) adding functional ingredients, and (c) changing processing methods and parameters for foods, and optimizing (a) eating behavior, (b) preloading or co-ingestion of other macronutrients, and (c) meal sequence and history. The effectiveness of a strategy would depend on consumer acceptance, compatibility of the strategy with an existing food product, and whether it is economically or technologically feasible. A combination of two or more strategies is recommended for greater effectiveness and flexibility.

Optimized germinated soybean/cornstarch extrudate and its in vitro fermentation with human inoculum

The aim of this work was to optimise a soybean/cornstarch extrudate by adjusting a central composite design and to maximise a product with a high protein and resistant starch (RS) content by evaluating the indigestible fractions through in vitro colonic fermentation and production of short-chain fatty acids (SCFAs) with potential health benefits. According to the response surface analysis and RS maximisation results, an optimisation of the independent variables was obtained as follows: 32.5% feed moisture, 144 °C extrusion temperature and a proportion of 44% germinated soybean flour and 56% cornstarch. A product with a 2.11% expansion index, 6.25 N hardness, a glycaemic index of 49 and 12% resistant starch was obtained. The optimised extrudate showed a 36% indigestible fraction and high fermentability with respect to that of the lactulose control. Furthermore, the decrease in pH was inversely proportional to the production of SCFAs and the volume of gas generated. Acetic, propionic, and butyric acids were produced at a molar ratio of 62:27:11, while the highest SCFA concentrations were found 48 h after incubation. The RS of the optimised extruder was a viable substrate for in vitro colonic fermentation, suggesting that it is a good food source to produce SCFAs, which could exert an effect on the regulation of lipid and glucose metabolism.

Evaluation of the behaviour of unripe banana flour with non-conventional flours in the production of gluten-free bread

Gluten-free breads were developed by incorporating unripe banana flour in a blend of alternative flour/cassava starch, 45/50. A factorial design was applied to determine the simultaneous effect of percentage of unripe banana flour (2, 8, 15%) and the type of alternative flour (quinoa, oyster mushroom, yellow pea and lentil flour) on structural and colour properties of bread. Principal component analysis was used to evaluate the behaviour of the formulations from a comprehensive perspective. Three formulations, denoted as P8 (pea + 8% unripe banana flour), Q15 (quinoa + 15% unripe banana flour) and L15 (lentil + 15% unripe banana flour) exhibited the closest profiles to reference (wheat bread). Breads with oyster mushroom flour showed a profile significantly different from the rest of formulations. The interactions among the factors were significant for all studied properties and showed that the unripe banana flour fortification did not lead to proportional responses on the bread properties, but the behaviour of unripe banana flour in breadmaking relied on the percentage and the type of alternative flour used. The P8, Q15 and L15 exhibited high fibre content and carbohydrate content lower than the reference. In addition, P8 formulation can be classified as intermediate glycaemic index.

The microstructure of starchy food modulates its digestibility

Starch is the main carbohydrate in human nutrition and shows a range of desired food properties. It has been demonstrated that fast digestion of starchy food can induce many health issues (e.g., hyperglycaemia, diabetes, etc.); therefore, how to modulate its digestion is an interesting topic. Previous studies have revealed that the microstructure and digestibility of starchy food of different botanical origin or from multiple processes are quite different; modulating starch digestion by retaining or altering its microstructure may be effective. In the present review, the current knowledge of the relationship between microstructural changes to starchy food and its digestibility at molecular, cell and tissue, and food processing levels is summarized. New technologies focused on microstructure studies and ways to manipulate food microstructure to modulate starch digestibility are also reviewed. In particular, some insights focusing on the future study of microstructure and the digestibility of starchy food are also suggested.

Banana starch and molecular shear fragmentation dramatically increase structurally driven slowly digestible starch in fully gelatinized bread crumb

The role of native (NB) and extruded (EB) banana starch, and a 1:1 native:extruded banana starch composite (MB), in slowing down the starch digestibility of bread crumb and crust was investigated. During extrusion, the molecular weight of banana starch was reduced from 2.75 × 10⁸ to 4.48 × 10⁶ g/mol (HPSEC-MALS-RI). Results showed a slowly digestible starch (SDS) increase from 1.09% (control) to 4.2, 6.6, and 7.76% in NB, MB and EB crumbs (fully gelatinized), respectively. DSC data attributed this occurrence to the formation of supramolecular structures upon storage involving amylopectin branches (especially those from fragmented amylopectin in EB). The hedonic sensory test showed no differences in overall liking between MB, EB and control, validating feasibility of including banana in the formulation. For the first time, this study shows a molecular size reduction as a strategy to manufacture selected starches that result in highly gelatinized baked products rich in structurally driven SDS.

Efficacy of different fibres and flour mixes in South-Asian flatbreads for reducing post-prandial glucose responses in healthy adults

PURPOSE

Type 2 diabetes (T2DM) is increasing, particularly in South-East Asia. Intake of high-glycaemic foods has been positively associated with T2DM, and feasible routes to reduce the glycaemic response to carbohydrate-rich staple foods are needed. The research question was whether different fibre and legume flour mixes in flatbreads lower postprandial glucose (PPG) responses.

METHODS

Using a balanced incomplete block design, we tested the inclusion of guar gum (GG), konjac mannan (KM) and chickpea flour (CPF) in 10 combinations (2/4/6 g GG; 2/4 g KM; 15 g CPF, and 10 or 15 g CPF plus 2 or 4 g GG) in 100 g total of a control commercial high-fibre flatbread flour mix ("atta") on PPG in 38 normal-weight adults. Self-reported appetite was an additional exploratory outcome. An in vitro digestion assay was adapted for flatbreads and assessed for prediction of in vivo PPG.

RESULTS

Flatbreads with 6 g GG, 4 g KM, and 15 g CPF plus 2 or 4 g GG reduced PPG ≥30 % (p < 0.01), while no other combinations differed significantly from the control. A statistical model with four in vitro parameters (rate of digestion, %RDS, AUC, carbohydrate level) was highly predictive of PPG results (adjusted R 2 = 0.89). Test products were similar to the control for appetite-related measures.

CONCLUSIONS

The results confirm the efficacy of specific additions to flatbread flour mixes for reducing PPG and the value of the in vitro model as a predictive tool with these ingredients and product format. This trial is registered at ClinicalTrials.gov with identifier NCT02671214.

Bread making technology influences postprandial glucose response: a review of the clinical evidence

Lowering postprandial glucose and insulin responses may have significant beneficial implications for prevention and treatment of metabolic disorders. Bread is a staple food consumed worldwide in a daily basis, and the use of different baking technologies may modify the glucose and insulin response. The aim of this review was to critically record the human studies examining the application of different bread making processes on postprandial glucose and insulin response to bread. Literature is rich of results which show that the use of sourdough fermentation instead of leavening with Saccharomyces cerevisiae is able to modulate glucose response to bread, whereas evidence regarding its efficacy on lowering postprandial insulin response is less clear. The presence of organic acids is possibly involved, but the exact mechanism of action is still to be confirmed. The reviewed data also revealed that the alteration of other processing conditions (method of cooking, proofing period, partial baking freezing technology) can effectively decrease postprandial glucose response to bread, by influencing physical structure and retrogradation of starch. The development of healthier bread products that benefit postprandial metabolic responses is crucial and suggested baking conditions can be used by the bread industry for the promotion of public health.

Mepiquat: A Process-Induced Byproduct in Roasted Cereal-Based Foodstuffs

Mepiquat, a growth regulator widely used in agriculture, is also known as a process-induced byproduct formed in coffee from natural constituents during heat treatments such as roasting. This study examines mepiquat formation in cereal-based foodstuffs treated at sufficiently high temperature to trigger methyl transfer reactions that involve glycine betaine and choline naturally present in cereals. Color measurements of roasted barley grains revealed a correlation between thermal treatment and mepiquat content. Trials at industrial scale on instant beverages composed of roasted cereals demonstrated significant increases in mepiquat during the thermal process (in the range of 140-205 μg/kg in final products). A targeted survey of commercial products showed mepiquat in the range 69-381 μg/kg in powdered cereal instant drinks and 42-168 μg/kg in mugicha tea, a roasted barley infusion. These findings will not significantly affect the exposure of consumers to mepiquat due to the low amounts detected.

Breakdown pathways during oral processing of different breads: impact of crumb and crust structures

An in vivo approach permitted to determine the respective contribution of bread properties and physiology characteristics to oral breakdown pathways.

Impact of preloading either dairy or soy milk on postprandial glycemia, insulinemia and gastric emptying in healthy adults

PURPOSE

Milk protein ingestion reduces post-meal glycemia when consumed either before or together with carbohydrate foods. The aim of this study was to compare the effects of dairy and soy milk consumed either before (preload) or together with (co-ingestion) a carbohydrate (bread), on postprandial blood glucose, insulin and gastric emptying in healthy participants.

METHODS

Twelve healthy Chinese male participants were studied on five separate occasions using a randomized crossover design. White wheat bread consumed with water was used as a reference meal. Capillary and venous bloods were sampled pretest and 3.5 h post-test meal for glucose and insulin measurement. Gastric emptying was measured using real-time ultrasonography.

RESULTS

Co-ingestion of dairy milk or soy milk with bread lowered postprandial blood glucose response and glycemic index. Co-ingesting soy milk with bread increased insulin response and insulinemic index significantly compared to co-ingestion of dairy milk and preload treatments. Preloads (30 min prior to bread) significantly lowered postprandial glycemia and insulinemia compared to co-ingestion. Gastric emptying was slower after co-ingesting dairy milk with bread than after reference meal.

CONCLUSIONS

Preloading either soy milk or dairy milk results in greater reduction in glycemic response compared to co-ingestion alone. This dietary practice may have therapeutic advantage in communities consuming high GI diets. Optimal glucose control may have the potential for increasing the time of transition from prediabetes to type 2 diabetes in Asian communities.

CLINICAL TRIAL REGISTRATION

This trial was registered at clinicaltrials.gov as NCT 02151188.

Glycemic responses, appetite ratings and gastrointestinal hormone responses of most common breads consumed in Spain. A randomized control trial in healthy humans

The present study was carried out to determine the glycemic index (GI), glycemic load (GL), insulinemic index (InI), appetite ratings and postprandial plasma concentrations of gastrointestinal hormones related to the control of food intake after the ingestion of the five most common breads consumed in Spain with different compositions and manufacturing processes. Twenty-two healthy adults participated in a randomized crossover study. The breads tested were Ordinary, Precooked-Frozen, Candeal-flour, Alfacar whites and Wholemeal. All breads portions were calculated to supply 50 g of available carbohydrates. In addition, 50 g of glucose was used as a reference. A linear mixed-effects model was used to compare data calculated for all breads with glucose load. The GI value varied from 61 for the Wholemeal, to Alfacar 68, Ordinary 76, and 78 and 86 for the Precooked-Frozen and Candeal-flour breads, respectively. Wholemeal and Alfacar had lower GI than glucose. All tested breads had a lower GL (ranged 9 to 18) compared with glucose. Wholemeal GL was similar to Alfacar, but lower than the other white breads. InI were significantly lower for all breads (ranged 68 to 73) compared with glucose, and similar among them. The intake of the Wholemeal bread led to a higher release of gastric inhibitory polypeptide compared with the Ordinary and Precooked breads and to a higher release of pancreatic polypeptide compared with the Precooked-Frozen bread. All breads affected appetite ratings similarly. In conclusion, based on GL, the Wholemeal bread would be expected to exert a favorable glycemic response.