White Pan Bread and Sugar‐Snap Cookies Containing Wheat Starch Phosphate,A Cross‐Linked Resistant Starch

Pup‐loaf bread was made with 10, 30, and 50% substitution of flour with wheat starch phosphate, a cross‐linked resistant starch (XL‐RS4), while maintaining flour protein level at 11.0% (14% mb) by adding vital wheat gluten. Bread with 30% replacement of flour with laboratory‐prepared XL‐RS4 gave a specific volume of 5.9 cm³/g compared with 6.3 g/cm³ for negative control bread (no added wheat starch), and its crumb was 53% more firm than the control bread after 1 day at 25°C, but 13% more firm after 7 days. Total dietary fiber (TDF) in one‐day‐old bread made with commercial XL‐RS4 at 30% flour substitution increased 3–4% (db) in the control to 19.2% (db) in the test bread, while the sum of slowly digestible starch (SDS) plus resistant starch (RS), determined by a modified Englyst method, increased from 24.3 to 41.8% (db). The reference amount (50 g, as‐is) of that test bread would provide 5.5 g of dietary fiber with 10% fewer calories than control bread. Sugar‐snap cookies were made at 30 and 50% flour replacement with laboratory‐prepared XL‐RS4, potato starch, high‐amylose (70%) corn starch, and commercial heat‐moisture‐treated high‐amylose (70%) corn starch. The shape of cookies was affected by the added starches except for XL‐RS4. The reference amount (30 g, as‐is) of cookies made with commercial XL‐RS4 at 30% flour replacement contained 4.3 g (db) TDF and 3.4 g (db) RS, whereas the negative control contained 0.4 g TDF and 0.6 g RS. The retention of TDF in the baked foods containing added XL‐RS4 was calculated to be >80% for bread and 100% for cookies, while the retention of RS was 35–54% for bread and 106–113% for cookies.     

Hot‐Water Solubilities and Water Sorptions of Resistant Starches at 25°C

Resistant starches (RS) were prepared from wheat starch and lintnerized wheat starch by autoclaving and cooling and by cross‐linking. Heat‐moisture treatment also was used on one sample to increase RS. The experimental resistant starches made from wheat starch contained 10–73% RS measured as Prosky dietary fiber, whereas two commercial resistant starches, Novelose 240 and 330, produced from high‐amylose maize starch, contained 58 and 40%, respectively. At 25°C in excess water, the experimental RS starches, except for the cross‐linked wheat starch, gained 3–6 times more water than the commercial RS starches, and at 95°C gained 2–4 times more. Cross‐linked RS4 wheat starch and Novelose 240 showed 95°C swelling powers and solubilities of 2 g/g and 1%, and 3 g/g and 2%, respectively. All starches showed similar water vapor sorption and desorption isotherms at 25°C and water activities (a_w) < 0.8. At a_w 0.84–0.97, the resistant starches made from wheat starch, except the cross‐linked wheat starch, showed ≈10% higher water sorption than the commercial resistant starches.     

Characterization of resistant starch type III from banana (Musa acuminata)

Banana starch (Musa acuminata var. Nandigobe) was evaluated for its use in generating resistant starch (RS) type III. Structural, physicochemical, and biological properties of these products were analyzed. The investigated process includes debranching of the native starch and retrogradation under different storage temperatures and starch concentrations. After enzymatic debranching, a high amount of low-molecular-weight polymers with a degree of polymerization between 10 and 35 glucose units beside a higher molecular weight fraction were found. The resulting products comprised RS contents of about 50%. After heat-moisture treatment, the RS yield increased up to 84%. Peak temperatures of about 145 degrees C found in DSC measurements pointed to a high thermal stability of the RS products. In vitro fermentations of the RS products, carried out with intestinal microflora of healthy humans, resulted in a molar ratio of acetate:propionate:butyrate of about 49:17:34. The established method allowed the production of a high-quality RS with prebiotic properties for health preventing applications.     

Physiological and metabolic properties of a digestion-resistant maltodextrin, classified as type 3 retrograded resistant starch

There is a growing interest in highly fermentable dietary fibers having the potential to reduce risks of disease through the production of short-chain fatty acids (SCFA). Recently a digestion-resistant retrograded maltodextrin (RRM), classified as type 3 resistant starch was developed. Systematic work to determine its molecular and physiological properties was carried out to determine (1) the fraction resistant to digestion in vitro and in vivo, (2) its postconsumption effect on blood glucose in healthy volunteers, and (3) its in vitro fermentation pattern, at different ages, by use of pooled fresh human fecal inoculum. RESULTS: The digestion resistant fraction obtained in vivo from ileostomy patients (59.4%) is similar to that obtained by the AOAC method for measuring retrograded resistant starch (59.7%). The relative glycemic response after consumption of 50 g of RRM was 58.5% compared to glucose set as 100%. When exposed to colonic microbiota, in vitro obtained indigestible fractions behave similarly to those obtained in vivo in ileostomy patients. Fermentation of RRM and production of butyric acid is negligible during the first months of life but develops subsequently during weaning. In adults, RRM fermentation results in a high yield of SCFA, with butyrate representing 21-31 mol % of total SCFA. The high yield of SCFA during colonic fermentation, observed from weaning age on, as well as the potential to help reduce glycemic load may be of benefit to a number of health-related functions in the host. Further study on clear clinical end points is warranted.     

Structural stability and prebiotic properties of resistant starch type 3 increase bile acid turnover and lower secondary bile acid formation

Microbial metabolism is essential in maintaining a healthy mucosa in the large bowel, preferentially through butyrate specific mechanisms. This system depends on starch supply. Two structurally different resistant starches type 3 (RS3) have been investigated with respect to their resistance to digestion, fermentability, and their effects on the composition and turnover of bile acids in rats. RSA (a mixture of retrograded maltodextrins and branched high molecular weight polymers), which is more resistant than RSB (a retrograded potato starch), increased the rate of fermentation accompanied by a decrease of pH in cecum, colon, and feces. Because they were bound to RS3, less bile acids were reabsorbed, resulting in a higher turnover through the large bowel. Because of the rise of volume, the bile acid level was unchanged and the formation of secondary bile acids was partly suppressed. The results proved a strong relation between RS3, short chain fatty acid production, and microflora. However, butyrate specific benefits are only achieved by an intake of RS3 that result in good fermentation properties, which depend on the kind of the resistant starch structures.     

Cross‐Linked Resistant Starch: Preparation and Properties

Resistant starches (RS) were prepared by phosphorylation of wheat, waxy wheat, corn, waxy corn, high‐amylose corn, oat, rice, tapioca, mung bean, banana, and potato starches in aqueous slurry (≈33% starch solids, w/w) with 1–19% (starch basis) of a 99:1 (w/w) mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) at pH 10.5–12.3 and 25–70°C for 0.5–24 hr with sodium sulfate or sodium chloride at 0–20% (starch basis). The RS₄ products contain ≤100% dietary fiber when assayed with the total dietary fiber method of the Association of Official Analytical Chemists (AOAC). In vitro digestion of four RS₄ wheat starches showed they contained 13–22% slowly digestible starch (SDS) and 36–66% RS. However after gelatinization, RS levels fell by 7–25% of ungelatinized levels, while SDS levels remained nearly the same. The cross‐linked RS₄ starches were distinguished from native starches by elevated phosphorus levels, low swelling powers (≈3g/g) at 95°C, insolubilities (<1%) in 1M potassium hydroxide or 95% dimethyl sulfoxide, and increased temperatures and decreased enthalpies of gelatinization measured by differential scanning calorimetry.     

Influence of Botanical Source and Processing on Formation of Resistant Starch Type III

Influence of botanical source and gelatinization procedure (autoclaving or boiling) on resistant starch (RS) formation was investigated in starches from wheat, corn, rice, and potato. RS yields did not vary within the same sample but differed among samples with different starch botanical sources. Differences also existed in RS contents in native and retrograded starches. Slight or minor variations in RS values were found after both gelatinization procedures, although no clear pattern was found in the behavior of samples based on gelatinization procedure. The degree of polymerization (DP) of retrograded samples was assigned using high-performance anion exchange chromatography with pulsed amperometric detector (average DP 50–60), with no differences between autoclaved and boiled samples.     

Composite Durum Wheat Flour/Plantain Starch White Salted Noodles: Proximal Composition,Starch Digestibility,and Indigestible Fraction Content

In search of a way to improve the nutritional profile of noodles, we prepared them with various mixtures of durum wheat flour and isolated plantain starch, and tested their proximal composition. Cooked noodles were assessed for in vitro starch digestibility, indigestible fraction content, and predicted glycemic index. The protein content declined with the addition of plantain starch. Both total starch (TS) level and the content of starch available for digestible enzymes (AS) decreased as the plantain starch level increased, a pattern that may be related to increased starch lixiviation during cooking of noodles containing plantain starch. There was an inverse pattern for resistant starch (RS). RS content in control (durum wheat flour) noodles was ≈50% lower than in the samples containing plantain starch. The soluble indigestible fraction (SIF) content in all samples was higher than the insoluble counterpart (IIF). The total indigestible fraction varied according to the wheat substitution level. Although the hydrolysis index (HI) and predicted glycemic index (pGI) of plantain starch noodles were moderate and decreased as the plantain starch proportion rose. These composite noodles exhibited higher indices than the control sample, a phenomenon that may also be dependent on the product physical structure. Results indicate that in spite of the increased starch digestion rate, plantain starch noodles are a better source of indigestible carbohydrates than pure wheat starch pasta. This might have dietetic applications.     

Digestion residues of typical and high-beta-glucan oat flours provide substrates for in vitro fermentation

In vitro fermentabilities of the oat flour digestion residues (ODR) from two commercial oat lines with 4.7 and 5.3% beta-glucan and from two high-beta-glucan experimental lines with 7.6 and 8.1% beta-glucan were evaluated and compared with fermentations of lactulose, purified oat beta-glucan (POBG), and purified oat starch (POS). Substrates were fermented by using an in vitro batch fermentation system under anaerobic conditions for 24 h. The progress of the fermentation was studied by following the change in pH of the fermentation medium, production of short-chain fatty acids (SCFA) and gases, and consumption of carbohydrates. The substrate from the flour with the greatest amount of beta-glucan tended to have the greatest pH decline and the greatest total SCFA production. A significant correlation occurred between gas production and SCFA formation (R 2 = 0.89-0.99). Acetate was produced in the greatest amounts by all of the substrates except POBG, by which butyrate was produced in the greatest amount. More propionate and butyrate, but less acetate, were produced from high-beta-glucan ODR. With the given fermentation conditions, >80% of the total carbohydrate was depleted by the bacteria after 24 h. Glucose was the most rapidly consumed carbohydrate among other available monosaccharides in the fermentation medium. Overall, the high-beta-glucan experimental lines provided the best conditions for optimal in vitro gut fermentations.     

Volatile Compounds in Five Starches

Volatile compounds in commercial wheat, corn, potato, waxy corn, and tapioca starches and in laboratory‐prepared wheat, corn, and potato starches were collected, separated, and identified by a purge and trap concentrator (P&T) interfaced to a gas chromatograph (GC) equipped with a Fourier transform infrared detector (FTIRD) and a mass selective detector (MSD). Hexanal was the most abundant compound in the corn and potato starches and in the laboratory‐prepared wheat starch as determined by total ion chromatogram (TIC) peak areas. Hexanal was the third most abundant compound in commercial wheat starch after 2‐ethyl‐1‐hexanol and benzaldehyde. Among the volatile organics, the level of aldehydes was the highest, followed by alcohols, ketones, benzenes, esters, and terpenes. Specific compounds identified, the majority of which appear to be degradation products of lipid peroxidation, include hexanal, heptanal, octanal, nonanal, decanal, benzaldehyde, 2‐propanone, 2‐propanol, 1‐butanol, 2‐ethyl‐1‐hexanol, methylbenzene, and tetradecane. Waxy corn starch, which released a substantially higher level of total volatiles than all other starches, contained large amounts of pentyl, 2‐methyl‐1‐butyl, benzyl, and isobornyl acetates; and citronella and 1,8‐cineole. Tapioca starch contained few volatiles but did contain an increased level of 2‐propanol. No alcohols occurred in the commercial corn starch. Terpene compounds were detected only in commercial potato, waxy corn, and tapioca starches. Many volatiles detected in wheat and corn starches also were detected in the kernels of their commercial samples.     

Effect of Partial Acid Hydrolysis and Heat‐Moisture Treatment on Formation of Resistant Tuber Starch

Structural characteristics of resistant starch (RS) were investigated. Tuber starches, hydrolyzed with 1N HCl at 35°C for 8 hr followed by autoclaving‐cooling treatment, were heated at 100°C for 16 hr after adjusting the moisture content to 20 or 30%. RS content of the tuber starches ranged from 5.4 to 22.7% depending on the source and type of treatment. Gelatinization parameters of RS isolated from partially acid‐hydrolyzed starch with autoclaving‐cooling followed by heat‐moisture treatment (HMT) showed higher enthalpy (ΔH) values and lower peak temperature (T_p) compared with non‐acid‐hydrolyzed RS. R values, the difference between completion and initial temperatures, and ΔH of RS increased by HMT. The X‐ray diffraction patterns of potato and sweet potato RS isolated from partially acid‐hydrolyzed starch with autoclaving‐cooling showed distinct sharp peaks at 15, 25, 27, and 28°, which decreased by HMT.     

Morphological Changes of Granules of Different Starches by Surface Gelatinization with Calcium Chloride

Native starch granules of 11 selected cultivars (potato, waxy potato, sweet potato, normal maize, high‐amylose maize, waxy maize, wheat, normal barley, high‐amylose barley, waxy barley, and rice) were treated with a calcium chloride solution (4M) for surface gelatinization. The surface‐gelatinized starch granules were investigated using light microscopy and scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). In general, those starches with larger granule sizes required longer treatment time to complete the gelatinization. The salt solution treatment of starch was monitored by light microscopy and stopped when the outer layer of the granule was gelatinized. The surface gelatinized starch granules were studied using scanning electron microscopy. On the basis of the gelatinization pattern from calcium chloride treatments, the starches could be divided into three groups: 1) starches with evenly gelatinized granule surface, such as normal potato, waxy potato, sweet potato, maize, and high‐amylose maize; 2) starches with salt gelatinization concentrated on specific sites of the granule (i.e., equatorial groove), such as wheat, barley, and high‐amylose barley; and 3) starches that, after surface gelatinization, can no longer be separated to individual granules for SEM studies, such as waxy barley, waxy maize, and normal rice. The morphology of the surface gelatinized starch resembled that of enzyme‐hydrolyzed starch granules.     

Importance of Location of Digestion and Colonic Fermentation of Starch Related to Its Quality

For decades, quality of starch‐based foods has been associated with the in vivo measured glycemic index or the in vitro digestion rate‐based categories of rapidly digestible, slowly digestible, and resistant starch (RS). Glycemic index has been related to health‐based endpoints mostly through correlative or observational studies, with mechanisms proposed but not well established. Here, we bring forth the concept of locational delivery of glucose from dietary starches to the distal small intestine to elicit an ileal brake effect, as well as short‐chain fatty acid production from RS fermentation to cause a colonic brake. Both effects slow gastric emptying and, in turn, extend nutrient (i.e., energy) delivery to the body and may decrease appetite and promote weight management. Slowly digestible starches are currently a popular topic of research, although where they are digested and the released glucose is delivered in the small intestine is not known. A proposal is to further study and establish this mechanism of appetite and food intake regulation so that starch‐based ingredients and foods can be developed that promote both the ileal and colonic brake mechanisms.     

Effects of Heat Stress and Cultivar on the Functional Properties of Starch in Chinese Wheat

Heat stress during the grain‐filling stage is a major limiting factor for improving Chinese wheat production, and its effect on functional properties of flours and starches in 10 leading cultivars from the Yellow and Huai Valleys grown under normal and heat‐stress environments was investigated. Heat stress during the grain‐filling stage decreased total starch content but increased protein and lipid contents of wheat grains. Amylose content of wheat starch was little altered under a heat‐stress environment. Heat stress did not significantly change swelling power and starch solubility of wheat starches but significantly decreased swelling power of wheat flours. Pasting viscosities of wheat starches and flours were affected differentially by heat stress. Heat stress had a significant effect on gelatinization and retrogradation properties of starches. The in vitro enzymatic digestibility of wheat starches was affected slightly by heat stress. Analysis of variance indicated that heat stress had a significant effect on some functional properties of starch and flour, although the largest source of variability in these properties was cultivar.     

Understanding the Physicochemical and Functional Properties of Wheat Starch in Various Foods

This report highlights the structure and myriad properties of wheat starch in various food systems. Granule shape, size, and color, plus the proportion of A‐ and B‐granules, amylose content, and molecular structure largely determine its functionality in food. The role of wheat starch is portrayed in three categories of flour‐based foods that differ in water content. Wheat starch influences the appearance, cooking characteristics, eating quality, and texture of pasta and noodles, and its role is more than a filler in yeast‐leavened bread products. Recent developments in the properties and applications of commercially important wheat pyrodextrins and RS4‐type resistant wheat starches are reported, along with their use to produce fiber‐fortified foods. Gluten‐free foods are also discussed.     

Physical properties of octenyl succinic anhydride modified rice,wheat, and potato starches

The physical properties of octenyl succinic anhydride (OSA) starches prepared from rice, wheat, and potato starches were studied. Rice and wheat OSA starches had significantly higher peak viscosity (PV), hot paste viscosity (HPV), and cool paste viscosity (CPV), but potato OSA starch had only significantly higher CPV, relative to the native starch. The gel hardness was higher with lower degree of substitution (DS) but lower with higher DS OSA compared to native starch. The swelling volumes (SV) of rice and wheat OSA starches were significantly higher compared to native starch, but the SV of potato OSA starch was slightly lower at high DS. The gelatinization temperature (GT) of rice OSA starches was sharply lower at low DS; for wheat OSA starch it was slightly lower even at high DS, but potato OSA starches had higher GT than the native starch. The enthalpy of all the OSA starches decreased gradually with increased DS. This study showed that the magnitude of changes in physical properties of OSA-modified starches depends not only on their DS but also on the botanical origin of the native starches.     

冻结-高压湿热解冻对多种淀粉中支链淀粉断裂的影响

冻结和高压湿热解冻是含淀粉面团在食品加工过程的必要工艺,在此过程中淀粉球破裂、部分支链淀粉断裂成为直链淀粉,给面团和食品的物理性状控制带来许多不可预见的结果。该文通过研究加热时间、加热温度、冷冻时间和解冻时间对糊化后的小麦、甘薯、马铃薯和玉米淀粉中直链淀粉含量的影响,间接反映支链淀粉断裂情况,结合冻结解冻前后淀粉分子量分布、链长分布、光学和电子显微镜图谱提出了冻结-解冻过程不同淀粉中支链淀粉可能断裂方式。结果表明,4种淀粉中的直链淀粉含量先升高后下降,直链淀粉含量在4种淀粉的中达到峰值的时间分别为48,48,48,72 h。光学显微照片观察表明,冻融处理会导致更多凝胶化淀粉球的破裂。对于小麦支链淀粉,冻融解冻过程支链淀粉中侧链长度为5、6、7个葡萄糖残基的侧链对应3种可能的断裂方式:2+2+1、2+2+2及2+2+2+1;对于甘薯支链淀粉,支链淀粉中侧链长度为10、11和13个葡萄糖残基的侧链对应3种可能的断裂方式:3+3+4、2+2+3+4及2+2+2+3+4;对于马铃薯支链淀粉,支链淀粉中侧链长度为5和6个葡萄糖残基的侧链对应3种可能的断裂方式:2+3、2+4、3+3;而玉米支链淀粉中,支链淀粉中侧链长度为7、8、9个葡萄糖残基的侧链对应3种可能的断裂方式:2+5,3+5,和3+3+3(其中1表示1个葡萄糖;2表示含2个葡萄糖的麦芽糖、3表示含3个葡萄糖的麦芽多糖、4表示含4个葡萄糖的麦芽多糖和5表示含5个葡萄糖的麦芽多糖)。该论文结果为培育具有冻融稳定性的淀粉种子提供一种全新的思路,即通过基因方法控制植物减少容易断裂淀粉侧链的合成。     

Composition,Functional Properties,Starch Digestibility,and Cookie‐Baking Performance of Dry Bean Powders from 25 Michigan‐Grown Varieties

The chemical composition, functional properties, starch digestibility, and cookie‐baking performance of bean powders from 25 edible dry bean varieties grown in Michigan were evaluated. The beans were ground into coarse (particle size ≤1.0 mm) or fine (≤0.5 mm) powders. Starch and protein contents of the bean powders varied between 34.4 and 44.5% and between 19.1 and 26.6% (dry basis [db]), respectively. Thermal properties, pasting properties, and water‐holding and oil‐binding capacities of the bean powders differed and were affected by particle size. After blending the bean powders with corn starch (bean/starch = 7:3, db), the blends were used for cookie baking following a standard method ( 1 Approved Method 10‐54.01). Generally, the cookies baked from the fine bean powders had smaller diameters, greater thicknesses, and greater hardness values than those from the coarse counterparts. Differences in the cookie‐baking performances of the bean powders were observed among the 25 varieties. Larger proportions of resistant starch (RS) were retained in the bean‐based cookies (54.7–126.7%) than in the wheat‐flour‐based cookies (10.4–19.7%) after baking. With higher contents of RS and protein, the bean‐based cookies had more desirable nutritional profiles than those baked from wheat flour alone.     

Packing Characteristics of Starch Granules

The rheological properties of granular materials and dispersions of solid particles in fluids are dependent on the packing characteristics of the particles. Maximum packing fractions (Φ_m) have been measured for corn, wheat, rice, potato, and amaranth starches, in the dry state and dispersed in either ethanol or hexane, using a tapping method. The observed maximum packing fraction increases with tapping time to a constant value. Values measured for dry starches were lower than those measured in liquids and reflect the effects of granule shape and intergranular friction. Values measured in fluids for potato, corn, and wheat starches were all similar in magnitude, and in the range of values (0.58–0.63) for random loose packing and random close packing of monodisperse spheres. Values for amaranth and rice starches were significantly lower due to agglomeration and clumping of individual granules. Blends of corn and potato starches show a slight enhancement of packing, with some Φ_m values greater than potato starch, consistent with data for bimodal blends of spheres. Blends of rice and potato starches displayed enhanced packing above ideal mixing but did not exceed the packing fraction of the potato starch. Knowledge of starch packing fractions is required for fundamental understanding of the rheological properties of granular starch‐filled materials and important for predicting processing characteristics.     

Characterization of Resistant Starch Samples Prepared from Two High‐Amylose Maize Starches Through Debranching and Heat Treatments

The aim of the present study was to investigate effects of debranching, autoclaving‐storing cycles, and drying processes (oven‐drying or freeze‐drying) on RS contents, thermal, pasting, and functional properties of high‐amylose maize starches (Hylon V and Hylon VII). The resistant starch (RS) contents increased (≤57.8%) with increasing autoclaving‐storing cycles. RS contents of oven‐dried samples were higher than those of freeze‐dried samples due to ongoing retrogradation of starch during oven drying at 50°C. Debranching caused a significant decrease in peak transition temperature and enthalpy values as compared with native starches. Solubility and water binding values of RS preparations were higher than those of native starches. Addition of native and autoclaved samples had improving effect on emulsion properties of albumin. Cold viscosity values of oven‐dried samples were lower as compared with freeze‐dried samples; this might be due to higher number of H‐bonds in the oven‐dried samples expected to be formed during drying. Debranching and autoclaving‐storing cycles caused decreases in peak, breakdown, and final viscosity values. The results of present study showed that debranching and heat treatments increased the RS contents and improved the functional properties of high‐amylose maize starches.