High-amylose Wheat Flour Research Articles

Physico-chemical and nutritional properties of different high-amylose wheat breads

High-amylose wheat flour has the potential to improve the nutritional value of end products due to a higher resistant starch content than common wheat flour. High-amylose (45% amylose) and type 0 (control, 28% amylose) wheat flours were used for the production of bread. In particular, the direct bread-making method where all the ingredients are mixed together was compared with indirect process carried out in several steps. Various parameters like moisture, weight, volume, resistant starch and crumb hardness were evaluated during a storage period of seven days. The collected outcomes showed that bread with a high amylose content had higher moisture content and lower volume after baking and during storage, regardless of the production method used. The amount of resistant starch, which was four times higher than in type 0 control bread, remained unchanged during the storage. The initial and final values of crumb hardness were similar for the different breads, but fitting the hardness data to a kinetic model, it was found that the staling of high-amylose bread was slower than that of type 0 control bread. Overall, the results of this study demonstrated that high-amylose flour can be used to produce high quality bread with improved nutritional properties.

A Novel high-amylose wheat-based functional cereal soup (tarhana) with low glycemic index and high resistant starch

This study investigated the potential of high-amylose wheat flour (Svevo-HA) to enhance the dietary profile of tarhana, a traditional Mediterranean fermented cereal yogurt mixture. The moisture content of tarhana powders ranged from 7.81% to 11.64%. Color parameters varied depending on the type of flour used, with Svevo-HA samples demonstrating decreased L* values and increased a* and b* values. Mineral compositions differed significantly among tarhana samples, with higher levels of K, Mg, Mn, Fe, Cu, and Zn observed in samples prepared with Svevo-HA. Gallic acid was identified as the major phenolic compound in all the tarhana samples for free fraction, while ferulic acid was determined as the major phenolic compound for its bound form. Supplementation of tarhana soups with heat-treated Svevo-HA flour increased the resistant starch content and decreased in vitro glycemic index value compared to soups prepared with conventional wheat flour. These findings highlight the potential of utilizing Svevo-HA flour to develop healthier versions of traditional foods.

Effect of Three Bakery Products Formulated with High-Amylose Wheat Flour on Post-Prandial Glycaemia in Healthy Volunteers.

Both Glycaemic index (GI) and Glycaemic Load (GL) were introduced to measure the impact of a carbohydrate-containing food on blood glucose. From this perspective, high-amylose (HA) flours, with a higher percentage of resistant starch (RS), may represent a suitable raw material to improve the glycaemic response. The present work aims to investigate the GI of HA bakery products (biscuits, taralli and bread) compared to products obtained from conventional flour. Ten healthy volunteers were enrolled and their capillary blood glucose was measured every 15 min for 2 h after the consumption of HA and control products containing 50 g of available carbohydrates. On average, in the three bakery products, the amount of total starch replaced by RS was equal to 12%. HA biscuits and HA bread showed significantly lower GI than their control counterparts (p = 0.0116 and p = 0.011, respectively) and better glycaemic control. From the survey to assess liking and willingness to pay on HA snacks, HA packages received an average premium of €0.66 compared to control products. Although HA flour results in lower GI in both biscuits and bread, further studies are needed to evaluate the correct composition of HA products to have beneficial effects on post-prandial glycaemia.

High-amylose wheat tortillas with reduced in vitro digestion and enhanced resistant starch content

Increased nutritional functionality in bread and noodles have been reported with the incorporation of high amylose wheat flour (HAWF). Here, we broaden the application of HAWF and report structure-function-nutrition relationships for tortillas prepared with 50% and 100% incorporation of HAWF. The breaking force and extensibility of the HAWF tortillas were lower than controls resulting from incompletely gelatinized high-amylose wheat starch (HAWS). The digestion degree of tortillas was significantly reduced by increase of amylose content due to HAWS structural features and enzyme hindrance effects of greater protein content, with resistant starch (RS) content increasing from ∼3% in control (32% amylose) to ∼12% in tortillas with 71% amylose and ∼23% in tortillas with 84% amylose. In addition, tortillas showed lower starch digestion and higher RS than loaf bread or noodle counterparts. This demonstrates that wheat food in-vitro enzyme hydrolysis is not only a function of starch structure, but also the local density of the microstructure formed during food processing.

Characterization of Fresh Pasta Made of Common and High-Amylose Wheat Flour Mixtures.

This study aims to assess the main biochemical, technological, and nutritional properties of a few samples of fresh pasta composed of commercial common wheat flour blended with increasing percentages, ranging from 0 to 100%, of high-amylose wheat flour. Although the technological parameters of such samples remained practically constant, fresh pasta samples including 50 to 100% of high-amylose wheat flour were classifiable as foods with a low in vitro glycemic index of about 43%. However, only fresh pasta made of 100% high-amylose wheat flour exhibited a resistant starch-to-total starch ratio greater than 14% and was therefore eligible to claim a physiological effect of improved glucose metabolism after a meal, as according to EU Regulation 432/2012.

Perspective: Utilizing High Amylose Wheat Flour to Increase Dietary Fiber Intake of Children and Adolescents: A Health by Stealth Approach.

Children and adolescents have consistently failed to meet recommended levels of dietary fiber consumption, thus making fiber a nutrient of concern. The importance of adequate dietary fiber intake to attain a healthy diet necessitates the identification of fiber-rich and readily consumed food sources by youth. Grain-based foods derived from whole grains represent a strategic initiative to increase dietary fiber consumption and is consistent with the American diet pattern. Increased intake of foods made from whole grains have been positively associated with improved health outcomes but are also less preferred among youth compared to refined grain products, which make up the majority of their carbohydrate intake. Advances in the commercialization and availability of high amylose wheat flour, a source of resistant starch fiber, provides an opportunity to remedy the suggested acceptability issues of whole grain products indicative of sensory factors, without compromising the amount of fiber ingested. Resistant starch fiber consumption has been associated with health benefits including improved blood sugar management, improved markers of digestive and gut health, increased satiety, and a reduced inflammatory response among adults. The limited studies that indicate fiber's direct benefit among youth are largely observational, thereby necessitating the need for more controlled trials for these age groups. Replacing traditional refined wheat flour with refined high amylose wheat flour has the unique ability to increase dietary fiber consumption without compromising desired sensory and finished product characteristics and thus can help increase dietary fiber consumption in children and adolescents who struggle to meet adequate intakes of fiber.

Starch structure and exchangeable protons contribute to reduced aging of high-amylose wheat bread

Breads were prepared from wild-type wheat flour (WTWF) and high-amylose wheat flour (HAWF) with amylose content (AM) 71% and 84%. Melting enthalpy of recrystallized amylopectin (ΔHAP) increased significantly on storage for wild-type (WT), slightly for 71% AM but not at all for bread with 84% AM. Firmness of bread was positively related to AM content and ΔHAP. Exchangeable proton populations and mobility in high-amylose wheat bread (HAWB) crumb were higher than WT bread measured by 1H T2 NMR, consistent with the higher water content needed to make doughs from HAWF leading to the crumb network being more plasticized and hindering crumb aging. Although starch recrystallization and bread firming increased, no increase in enzyme-resistant starch (RS) content was observed during bread aging, with RS content only dependent on AM content. Although HAWB has a harder crumb than wild-type, it has greater shelf-life stability and higher nutritional value.

Milling and rheological properties of high amylose wheat

The technological quality of a high amylose bread wheat variety (amylose/amylopectin 1:0.7) was explored performing different milling protocols, with subsequent evaluation of the chemical composition and rheological properties of the milling fractions and recombined flours. High amylose wheat yielded a lower amount of flour (<50%) and less refined products compared to control line. Grain debranning improved flour yields, releasing more refined reduction products. The milling of high amylose wheat with a hard-wheat diagram enhanced flour yield and refining rate of products, also giving a semolina type flour that can be employed e.g. for the production of pasta and couscous. The high amylose flours are characterized by relevant levels of resistant starch (27% of total starch on average) that make them suitable for the production of functional foods in agreement with the EU Regulation 432/2012. In addition, from the experimental results, it was put in evidence that official protocols for rheological analysis of flours (gluten index, alveograph and falling number) should be adapted for high amylose wheat samples, due to the impact that the different starch composition has on dough properties, specifically on water absorption and viscosity. Overall, rheological features of high amylose wheat flours exhibited higher water absorption, stability, and altered starch pasting properties.

High-amylose wheat bread with reduced in vitro digestion rate and enhanced resistant starch content

High amylose wheat flour (HAWF) is a relatively new food ingredient, with potential for enhanced nutritional functionality of slower digestion and greater resistant starch levels compared to wild-type wheat flour (WTWF) products. This study focusses on the role of amylose content in the baking process and eating qualities of bread, made using an industry-standard rapid dough method. DSC, XRD and polarized light microscopy were used to monitor changes of ordered structure in starch after baking, and showed more retained crystalline structure in the high-amylose wheat bread (HAWB) than wild-type wheat bread (WTWB). Moreover, HAWB had lower loaf volume, more dense crumb structure, as well as higher hardness than WTWB. These starch structural and local density features subsequently lead to bread made with 100% or 50% HAWF being more resistant to enzyme hydrolysis compared to WTWB. Resistant starch levels were significantly increased by ∼11 and 12 times in bread made using 100% HAWF with amylose content 71% and 84% respectively, and ∼6 times in bread prepared with 50% incorporation HAWF (84% AM) than WTWB. The nutritional and physical properties of bread are highly correlated to starch amylose content (AM), starch thermal properties and crumb hardness, with AM playing the leading role. This study identifies the structural basis for flour amylose content effects in baking and nutritional functionality and can help guide development of nutritionally-enhanced foods with HAWF.

Noodles Made from High Amylose Wheat Flour Attenuate Postprandial Glycaemia in Healthy Adults.

Previous research has not considered the effect of high amylose wheat noodles on postprandial glycaemia. The aim of the study is to investigate the effect of consumption of high amylose noodles on postprandial glycaemia over 2-h periods by monitoring changes in blood glucose concentration and calculating the total area under the blood glucose concentration curve. Twelve healthy young adults were recruited to a repeated measure randomised, single-blinded crossover trial to compare the effect of consuming noodles (180 g) containing 15%, 20% and 45% amylose on postprandial glycaemia. Fasting blood glucose concentrations were taken via finger-prick blood samples. Postprandial blood glucose concentrations were taken at 15, 30, 45, 60, 90 and 120 min. Subjects consuming high amylose noodles made with flour containing 45% amylose had significantly lower blood glucose concentration at 15, 30 and 45 min (5.5 ± 0.11, 6.1 ± 0.11 and 5.6 ± 0.11 mmol/L; p = 0.01) compared to subjects consuming low amylose noodles with 15% amylose (5.8 ± 0.12, 6.6 ± 0.12 and 5.9 ± 0.12 mmol/L). The total area under the blood glucose concentration curve after consumption of high amylose noodles with 45% amylose was 640.4 ± 9.49 mmol/L/min, 3.4% lower than consumption of low amylose noodles with 15% amylose (662.9 ± 9.49 mmol/L/min), p = 0.021. Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy young adults, as characterised by the significantly lower blood glucose concentration and a 3.4% reduction in glycaemic response.

High-Amylose Wheat Lowers the Postprandial Glycemic Response to Bread in Healthy Adults: A Randomized Controlled Crossover Trial

Conventional wheat-based foods contain high concentrations of readily digestible starch that commonly give these foods a high postprandial glycemic response and may contribute to the development of type 2 diabetes and cardiovascular disease. The aim of this study was to determine if bread made from high-amylose wheat (HAW) and enriched in resistant starch dampens postprandial glycemia compared with bread made from conventional low-amylose wheat (LAW). This single-center, randomized, double-blinded, crossover controlled study involved 7 consecutive weekly visits. On separate mornings, 20 healthy nondiabetic men and women (mean age 30±3 y; body mass index 23±0.7 kg/m2) consumed a glucose beverage or 4 different breads (each 121 g); LAW-R (refined), LAW-W (wholemeal), HAW-R, or HAW-W. The starch contents of the LAW and HAW breads were 24% and 74% amylose, respectively. Venous blood samples were collected at regular intervals before and for 3 h after the breakfast meal to measure plasma glucose, insulin, ghrelin, and incretin hormone concentrations, and the incremental area under the curve (AUC) was calculated (mmol/L × 3 h). Satiety and cravings were also measured at 30-min intervals during the postprandial period. HAW breads had a glycemic response (AUC) that was 39% less than that achieved with conventional wheat breads (HAW 39±5 mmol/L × 3 h; LAW 64±5 mmol/L × 3 h; P<0.0001). Insulinemic and incretin responses were 24-30% less for HAW breads than for LAW breads (P<0.05). Processing of the flour (wholemeal or refined) did not affect the glycemic, insulinemic, or incretin response. The HAW breads did not influence plasma ghrelin, or subjective measures of satiety or cravings during the postprandial period. Replacing LAW with HAW flour may be an effective strategy for lowering postprandial glycemic and insulinemic responses to bread in healthy men and women, but further research is warranted. This trial was registered at the Australian and New Zealand Clinical Trials Registry as ACTRN12616001289404.

Studies on the Functional and Processing Properties of Novelty Polished, Waxy and High-amylose Wheat Flours

Functional and processing properties of novel wheat flours, such as polished, waxy and high-amylose wheat flours were determined. Polished flours increased the amounts of minerals and anti-oxidant activity, and the amounts of dietary fibers, phytic acids, ferulic acids and pentosans were 2, 3, 10 and 2 times more, and large amounts of damaged starches and higher maltose values were obtained, as compared with the common flour of CW. The distributions of proteins in polished flours were different depending on the portions (fractions) of wheat grains, and proteins of the innermost fraction showed low-allergic reactions. Baking method including long fermentation significantly improved the baking properties of polished flours, and especially sourdough method increased the free amino acids, reducing sugars and organic acids during fermentation. The CO2 gas in polished-flour-sourdoughs distinctly increased, and their pH, total titratable acidity levels and buffering capacity were significantly better than the CW-sourdough. As a result, the growth of lactic acid bacteria and yeasts in polished-flour-sourdoughs were accelerated during fermentation, and its substituted breads with middle or innermost fractions improved baking qualities having favorable volatile compounds, such as iso-butanol and β-phenyl ethyl alcohol, more than CW-sourdough bread. In contrast, waxy wheat flours improved the staleness of breadcrumbs during storage and its freshness after reheating, while high-amylose wheat flours increased amounts of resistant starch in breadcrumbs during storage. Moreover, waxy wheat flours increased viscous and sticky textures of boiled-noodles, and high-amylose wheat flours suppressed the damage of noodles during boiling with the similar qualities to the durum pasta. Consequently, these novel wheat flours would be sufficient foodstuffs with excellently nutritious, functional and processing properties to give additional values of new taste or functionality to their final products.

Waxy and high-amylose wheat starches and flours—characteristics, functionality and application

Starch is a predominant component of wheat grain. It plays an important role in appearance, structure and quality of food products. Starch consists of two kinds of glucose polymers (amylose and amylopectin) with the ratio of amylose/amylopectin ranging between 25–28 and 72–75%, respectively. The isoforms of granule-bound starch synthase (GBSS) are responsible for the biosynthesis of amylose fraction, whereas amylopectin synthesis is more complicated with concerted activities of the soluble starch synthase together with branching and de-branching enzymes. Recently, waxy (amylose-free) and high-amylose wheats produced through the development of new physicochemical and biological techniques provide the unique starch functional properties. The starches of these wheats have the specific structures and unique characteristics that are believed to enhance the quality of food products. In this review, we will focus on recent advances in the studies of the characteristics of waxy and high-amylose wheat flours and starches and their application for food processing. In addition, we also propose further research ideas for clearer understanding of their characteristics and for their effective utilization.

Formation of Enzyme‐Resistant Starch in Bread as Affected by High‐Amylose Wheat Flour Substitutions

ABSTRACTHigh‐amylose wheat flour was used to substitute for normal wheat flour in breadmaking and formation of resistant starch (RS) in bread during storage was determined. Substitution with high‐amylose wheat flour (HAF) decreased peak and final viscosities, breakdown, and setback. Doughs with HAF substitutions were weaker and less elastic, and absorbed more water than those of the normal wheat flour. After baking, RS contents in breads with 10, 30, and 50% HAF substitutions were 1.6, 2.6, and 3.0% (db), respectively, higher than that of the control (0.9%, db). The levels of RS increased gradually during storage for one, three, and five days. With substitutions of 30 and 50% HAF, the total levels of dietary fiber (DF) and RS in bread after five days of storage were 15.5 and 16.8% (db), respectively, as compared to 13.0% (db) in bread from the normal wheat flour. The loaf volumes and appearances of bread crumbs made from HAF substitutions of 10 and 30% were not significantly different from those of the control, whereas the substitution with 50% HAF decreased loaf volume and resulted in inferior appearance of breadcrumbs. The firmness of breadcrumbs increased along with increase in the level of HAF substitutions after baking. During storage, the firmness of breadcrumb with 10% HAF substitutions was higher than that of the control, whereas breads with 30 and 50% HAF substitutions had similar firmness to the control. As a result, HAF might be used to substitute for up to 50% normal wheat flour to make bread with acceptable bread quality and significantly high amount of RS.

Dough and Baking Properties of High‐Amylose and Waxy Wheat Flours

ABSTRACTThe dough properties and baking qualities of a novel high‐amylose wheat flour (HAWF) and a waxy wheat flour (WWF) (both Triticum aestivum L.) were investigated by comparing them with common wheat flours. HAWF and WWF had more dietary fiber than Chinese Spring flour (CSF), a nonwaxy wheat flour. Also, HAWF contained larger amounts of lipids and proteins than WWF and CSF. There were significant differences in the amylose and amylopectin contents among all samples tested. Farinograph data showed water absorptions of HAWF and WWF were significantly higher than that of CSF, and both flours showed poorer flour qualities than CSF. The dough of WWF was weaker and less stable than that of CSF, whereas HAWF produced a harder and more viscous dough than CSF. Differential scanning calorimetry data showed that starch in HAWF dough gelatinized at a lower temperature in the baking process than the starches in doughs of WWF and CSF. The starch in a WWF suspension had a larger enthalpy of gelatinization than those in HAWF and CSF suspensions. Amylograph data showed that the WWF starch gelatinized faster and had a higher viscosity than that in CSF. The loaves made from WWF and CSF were significantly larger than the loaves made from HAWF. However, the appearance of bread baked with WWF and HAWF was inferior to the appearance of bread baked with CSF. Bread made with WWF became softer than the bread made with CSF after storage, and reheating was more effective in refreshing WWF bread than CSF bread. Moreover, clear differences in dough and bread samples were revealed by scanning electron microscopy. These differences might have some effect on dough and baking qualities.