Showing papers in "Cereal Chemistry in 2002"
TL;DR: In this article, a review of the early literature on zein is presented, which reexamines the old literature and reconciles it with new zein research to illustrate some of the unique properties of and opportunities for zein.
Abstract: Corn is the largest and most important agricultural commodity in America. Zein, one of the components in corn, has long been investigated for uses other than food and feed. Zein is a unique and complex material, and it is one of the few cereal proteins extracted in a relatively pure form. Today, because of environmental concerns, interest in zein utilization is again growing. Some of the more important research on zein is more than 50 years old. Most of this work has been either forgotten, lost, or difficult to locate. Much of this work was done at the USDA laboratory in Peoria, IL. Since most early zein literature is still easily accessible at that laboratory, this review on zein has been prepared making use of this old literature. This review reexamines the old literature and reconciles it with new zein research to illustrate some of the unique properties of and opportunities for zein.
461 citations
TL;DR: The amino acid release was determined in wheat doughs supplied with salt, acid, dithiothreitol, or starter cultures to evaluate the relevance of the amino acid concentration on bread flavor.
Abstract: The amino acid release was determined in wheat doughs supplied with salt, acid, dithiothreitol, or starter cultures to evaluate the relevance of the amino acid concentration on bread flavor. Wheat flour proteinases almost linearly released amino acids and the highest activity of wheat flour proteinases was found in acidified and reduced doughs. The effects of starter cultures on amino acid concentrations depended on their composition. Yeasts exhibited a high demand for amino acids, however, the total amino acid concentrations were not markedly affected by lactic acid bacteria. The individual amino acid contents were determined by the pH during fermentation and microbial metabolism. The formation of proline was favored by values higher than pH 5.5, whereas release of phenylalanine, leucine and cysteine mainly occurred at lower pH. Ornithine was found only in doughs fermented with Lactobacillus pontis. To determine effects of the amino acid concentration on bread aroma, fermented doughs were evalua...
326 citations
TL;DR: In this article, resistant starches (RS) were prepared by phosphorylation of wheat, waxy wheat, corn, wheat, 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 and sodium tripolyphosphate (STMP) at pH 10.
Abstract: 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 potassi...
294 citations
TL;DR: In this article, the physicochemical properties of small and large granule wheat starches were investigated to reveal whether gelatinization properties and rheological behavior differ between size classes of wheat starch.
Abstract: The physicochemical properties of small- and large-granule wheat starches were investigated to reveal whether gelatinization properties and rheological behavior differ between size classes of wheat starch. All samples contained 60% water (w/w, wb). The starch granule size and shape were examined by scanning electron microscopy in the separated A- and B-type granule populations and in the whole wheat starch granule population. Differential scanning calorimetry (DSC) and electron spin resonance (ESR) analyses were performed in parallel with rheological measurements using dynamic mechanical thermal analysis (DMTA) to relate the viscoelastic changes to modifications in dynamic properties of aqueous solutions and structural disorganization of starch. The small (B-type) granules had slightly higher gelatinization temperature and lower gelatinization enthalpy than did the large (A-type) granules. Also, B-type granules had higher enthalpy for the amylose-lipid complex transition. Moreover, our results su...
245 citations
TL;DR: In this paper, the effect of sourdough starter cultures on the phase angle and the absolute value of the complex dynamic modulus were measured using a controlled stress rheometer.
Abstract: Investigations were made to test the effect of two different sourdough starter culture types on wheat dough and bread quality. Two single-strain starter cultures consisting of well-defined strains of lactic acid bacteria (Lactobacillus plantarum, L. brevis) and a traditional mixed-strain sourdough culture (containing L. crispatus, L. pontis, and Saccharomyces cerevisiae) were evaluated for their effects on the rheological characteristics of wheat dough using both fundamental rheological and standard baking tests. Two other doughs were also evaluated, one which was chemically acidified to a comparable pH value by the addition of lactic acid, and a control which was not acidified. Dynamic oscillation tests were performed using a controlled stress rheometer. The phase angle and the absolute value of the complex dynamic modulus were measured for all doughs at frequencies of 0.1–10 Hz. The addition of sourdough prepared using single-strain or mixed-strain cultures significantly increased the phase ang...
183 citations
TL;DR: The total plant sterol contents (free sterols and covalently bound structures) of the main cereals cultivated in Finland were determined in this article, and the results showed that the highest plant sterols content was observed in rye (mean content 95.5 mg/100 g, wb), whereas the total sterols contents of wheat, barley, and oats were 69.0, 76.1, and 44.7, respectively.
Abstract: The total plant sterol contents (free sterols and covalently bound structures) of the main cereals cultivated in Finland were determined. Furthermore, sterol contents were determined for different flour and bran fractions in the milling process of wheat and rye, as well as plant sterol contents in various milling and retail bakery products. The sample preparation procedure included acid and alkaline hydrolysis to liberate sterols from their glycosides and esters, respectively. Free sterols were extracted and, after recovery using solid-phase extraction, derivatized to trimethylsilyl ethers for gas chromatography (GC) analysis. We used GC with a mass spectrometer (MS) for identification. When two cultivars of rye, wheat, barley, and oats grown in the same year were compared, the highest plant sterol content was observed in rye (mean content 95.5 mg/100 g, wb), whereas the total sterol contents (mg/100 g, wb) of wheat, barley, and oats were 69.0, 76.1, and 44.7, respectively. In addition, the 10 ry...
181 citations
TL;DR: In this article, the effects of cultivar on dough properties of ground whole wheat durum and drying temperature on the physical and cooking quality of spaghetti made from semolina and whole wheat were evaluated.
Abstract: The effects of cultivar on dough properties of ground whole wheat durum, and the effects of cultivar and drying temperature on the physical and cooking quality of spaghetti made from semolina and whole wheat were evaluated. Rankings of cultivars based on dough properties were similar for whole wheat and semolina. Dough made from whole wheat was weak and had poor stability. Whole wheat spaghetti had a rough reddish brown surface compared with the very smooth, translucent yellow color of spaghetti made from semolina. The reddish brown color of whole wheat spaghetti was enhanced by high-temperature drying (70°C). Mechanical strength and cooking quality of spaghetti made from ground whole wheat or semolina varied with cultivar and with drying temperature. Compared with spaghetti made from semolina, whole wheat spaghetti had lower mechanical strength and cooked firmness and had greater cooking loss. Mechanical strength of whole wheat spaghetti was lower when dried at high temperature (70°C) than at lo...
156 citations
TL;DR: The properties and baking qualities of a novel high-amylose wheat flour (HAWF) and a waxy wheat flour (WWF) were investigated by comparing them with common wheat flours as discussed by the authors.
Abstract: The 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 thos...
154 citations
TL;DR: In this article, the effects of cross-linking waxy maize starch with phosphorous oxychloride (POCl3), sodium trimetaphosphate (STMP), or epichlorohydrin (EPI) on degree of swell and pasting properties were studied.
Abstract: The effects of cross-linking waxy maize starch with phosphorous oxychloride (POCl3), sodium trimetaphosphate (STMP), or epichlorohydrin (EPI) on degree of swell and pasting properties were studied. As expected, increased concentration of cross-linking agent resulted in decreased granule swelling potential, Q (mL/g). The slower acting reagents, STMP (4-hr reaction time) and EPI (17-hr reaction time), showed a similar relation between Q value and molar concentration of agent, which was different from the faster-acting POCl3 (30-min reaction time). Brabender viscoamylograph results show decreased peak viscosity with increasing amounts of cross-link agent due to increased inhibition to swelling. Brabender viscosities (BU) continued to increase after the time interval in which an uncross-linked sample would dissolve, which may be a sign of flocculation. The magnitude of BU for all of the treatments after 41 min, plotted versus calculated molar concentration of cross-linking agent, showed a similar tre...
151 citations
TL;DR: A waxy spring wheat (Triticum aestivum L.) genotype was fractionated into flour and starch by roller and wet-milling, respectively,.
Abstract: A waxy spring wheat (Triticum aestivum L.) genotype was fractionated into flour and starch by roller and wet-milling, respectively. The resultant flour and starch were evaluated for end-use properties and compared with their counterparts from hard and soft wheats and with commercial waxy and nonwaxy corn (Zea mays L.) starches. The waxy wheat flour had exceptionally high levels of water absorption and peak viscosity compared with hard or soft wheat flour. The flour formed an intermediate-strength dough that developed rapidly and was relatively susceptible to mixing. Analysis by differential scanning calorimetry and X-ray diffractometry showed waxy wheat starch had higher gelatinization temperatures, a greater degree of crystallization, and an absence of an amylose-lipid complex compared with nonwaxy wheat. Waxy wheat and corn starches showed greater refrigeration and freeze-thaw stabilities than did nonwaxy starches as demonstrated by syneresis tests. They were also similar in pasting properties,...
132 citations
TL;DR: In this paper, a series of wheat flour and blend samples with various breadmaking potentials were tested at a fixed water absorption of 54% and farinograph optimum water absorption, respectively.
Abstract: Measurements of creep-recovery of flour-water doughs were made using a dynamic mechanical analyzer (DMA) in a compression mode with an applied probe force of 50 mN. A series of wheat flour and blend samples with various breadmaking potentials were tested at a fixed water absorption of 54% and farinograph optimum water absorption, respectively. The flour-water doughs exhibited a typical creep-recovery behavior of a noncross-linked viscoelastic material varying in some parameters with flour properties. The maximum recovery strain of doughs with a fixed water absorption of 54% was highly correlated (r = 0.939) to bread loaf volume. Wheat flours with a large bread volume exhibited greater dough recovery strain. However, there was no correlation (r = 0.122) between maximum creep strain and baking volume. The maximum recovery strain of flour-water doughs also was correlated to some of the parameters provided by mixograph, farinograph, and TA-XT2 extension.
TL;DR: RefReflectance and transmittance visible and near-infrared spectroscopy were used to detect fumonisin in single corn kernels infected with Fusarium verticillioides.
Abstract: Reflectance and transmittance visible and near-infrared spectroscopy were used to detect fumonisin in single corn kernels infected with Fusarium verticillioides. Kernels with >100 ppm and <10 ppm could be classed accurately as fumonisin positive or negative, respectively. Classification results were generally better for oriented kernels than for kernels that were randomly placed in the spectrometer viewing area. Generally, models based on reflectance spectra have higher correct classification than models based on transmittance spectra. Statistical analyses indicated that including near-infrared wavelengths in calibrations improved classifications, and some calibrations were improved by including visible wavelengths. Thus, the color and chemical constituents of the infected kernel contribute to classification models. These results show that this technology can be used to rapidly and nondestructively screen single corn kernels for the presence of fumonisin, and may be adaptable to on-line detection...
TL;DR: L'Einkorn is a ble diploide (Triticum monococcum L) contenant des taux eleves de proteines and presentant une pigmentation jaune as discussed by the authors.
Abstract: L'Einkorn est un ble diploide (Triticum monococcum L.) contenant des taux eleves de proteines et presentant une pigmentation jaune. Il permettrait la fabrication de produits de cuissons enrichis en carotenoides et en proteines. Des bles riches en carotenoides, et plus particulierement en luteine, sont etudies, en vue de produire des produits cerealiers possedant des activites fonctionnelles.
TL;DR: In this paper, the glass transition temperature of gluten at different moisture levels was determined by differential scanning calorimetry and mechanical spectrometry, and the dynamic moduli (G′ and G″) of gluten with 10−40% moisture were measured as a function of temperature by pressure rheometry.
Abstract: The glass transition temperature of gluten at different moisture levels was determined by differential scanning calorimetry and mechanical spectrometry. The dynamic moduli (G′ and G″) of gluten with 10–40% moisture were measured as a function of temperature by pressure rheometry. At 10% moisture, gluten exhibited entangled polymer flow at 92–140°C and networking reactions at higher temperatures. At higher moisture levels, gluten experienced structured flow before networking cross-linking reactions. The onset temperature of the reaction zone was 120°C in 20% moisture gluten and 93°C at moisture levels of 30–40%. Softening of the vitrified network occurred at 184, 181, and 170°C in 20, 30, and 40% moisture gluten, respectively. A preliminary state diagram of gluten as a function of moisture and temperature was developed.
TL;DR: Several reduction conditions were used on a Canadian Western Red Spring (CWRS) farina to yield flours of comparable protein content within three specific particle size ranges (132,193, 110,132, 85,110 μm) at three starch damage levels (3.0, 3.9, 7.0 Megazyme units) as mentioned in this paper.
Abstract: Several reduction grinding conditions were used on a Canadian Western Red Spring (CWRS) farina to yield flours of comparable protein content within three specific particle size ranges (132–193, 110–132, 85–110 μm) at three starch damage levels (3.0, 3.9, 7.0 Megazyme units). White salted noodles (1% w/w NaCl) were initially processed at a fixed absorption (32%). Dynamic oscillatory and large deformation creep measurements indicated that doughs with lower starch damage, thick or thin, exhibited lower G′ (storage modulus), higher tan δ (G″ [loss modulus]/G′) values, and greater maximum strain during creep than doughs with higher starch damage. There were no clear trends between work input during sheeting and either starch damage or particle size. Instrumental texture analysis of raw noodles showed no significant differences due to either starch damage or flour particle size. Flours with fine particle size gave cooked noodles with the best textural attributes, whereas starch damage exhibited no cons...
TL;DR: In this article, a 20% waxy wheat flour blend was found to be optimal in retarding staling while producing bread quality comparable with the control with 3% shortening, however, as staling progressed over 3-5 days, significant firming of crumb was observed in the control sample compared with loaves containing waxy flour.
Abstract: Crumb softness and improved shelf life of bread is often achieved by incorporating expensive shortenings in the formulation. We hypothesized that similar results could be achieved by blending bread wheat flour with waxy (low amylose) durum wheat flour. White pan bread was baked from 10, 20, and 30% waxy durum wheat flour composites and evaluated for loaf volume and crumb firmness over a period of 0, 3, and 5 days. The loaf volumes were not affected by the waxy flour blends. However, as staling progressed over 3–5 days, significant firming of crumb was observed in the control sample compared with loaves containing waxy flour. The firmness was inversely proportional to the level of waxy flour used in the blend. A 20% waxy wheat flour blend was optimal in retarding staling while producing bread quality comparable with the control. It was further established that bread made with 20% waxy flour gave lower firmness values after 5 days of storage in comparison to bread made with 3% shortening. These res...
TL;DR: In this article, the branch chain-length distributions of amylopectins were determined by using highperformance anion exchange chromatography equipped with an amyloglucosidase reactor and a pulsed amperometric detector (HPAEC-ENZ-PAD).
Abstract: Starches from eight soft wheat samples (two parent lines and six offspring) were isolated; relationships between their structures and properties were examined. Branch chain-length distributions of amylopectins were determined by using high-performance anion exchange chromatography equipped with an amyloglucosidase reactor and a pulsed amperometric detector (HPAEC-ENZ-PAD). Results showed that the average chain length of the eight samples varied at DP 25.6–26.9. Starch samples of lines 02, 60, 63, 95, and 114 consisted of amylopectins with more long chains (DP ≥ 37) and longer average chain length (DP 26.2–26.9) than that of other samples. These starch samples of longer branch chain length displayed higher gelatinization temperatures (55.3–56.5°C) than that of other samples (54.4–54.9°C) and higher peak viscosity (110–131 RVU) and lower pasting temperature (86.3–87.6°C) than others (83–100 RVU and 88.2–88.9°C, respectively). The Mw of amylopectins, determined by using high-performance size exclusi...
TL;DR: In this article, the influence of the chemical attributes on the sensory profiles of oats was analyzed by statistical multivariate techniques (PLS regression) during a 12-month storage period, and significant changes in the sensory attributes of the native and processed oat groats were observed.
Abstract: Cereal Chem. 79(3):367–375 Changes in the sensory attributes, lipid composition, and amounts of volatile and phenolic compounds of native and processed (germinated and dried) crushed oat were followed during a 12-month storage period. The influence of the chemical attributes on the sensory profiles of oats was analyzed by statistical multivariate techniques (PLS regression). During the storage period, significant changes in the sensory profiles of the native and processed oat groats were observed. The stability of oat groats was significantly increased through germination and subsequent drying because the chemical changes causing rancidity and bitterness developed more slowly in the processed oat when compared with the native oat. In native oat, the most intensive changes due to deterioration had already occurred after one month of storage, whereas in processed oat, these changes were perceived considerably later. Stored oat that had deteriorated was evaluated as being musty and earthy in odor and bitter and rancid in flavor. The accumulation of free fatty acids and volatile compounds related to lipid oxidation were closely correlated with the development of the undesired sensory attributes described above. The total amount of phenolic compounds, as well as the volatile aromatic and branched chain compounds derived mainly from protein degradation, showed a significant relationship with favorable sensory attributes such as roasted odor and flavor. Lipid oxidation occurred during the storage and was observed both in the polar and in the nonpolar lipid classes of native oat, whereas in the processed oat, these changes were nonsignificant. Photo-oxidation of acylated fatty acids may significantly contribute to the development of volatile lipid oxidation products during storage.
TL;DR: In this article, Waxy maize and potato starches were impregnated with ionic gums (sodium alginate, CMC, and xanthan, 1% based on starch solids) and heat-treated in a dry state for 0, 2, or 4 hours at 130°C.
Abstract: Waxy maize (native and hydroxypropylated [HP]) and potato starches were impregnated with ionic gums (sodium alginate, CMC, and xanthan, 1% based on starch solids) and heat-treated in a dry state for 0, 2, or 4 hr at 130°C. Effects of the dry heating on paste viscosity (RVA) and clarity (light transmittance) were examined. Heat treatment with sodium alginate and CMC raised the paste viscosities of native and HP waxy maize starches, but decreased that of potato starch. Xanthan provided the most substantial changes in paste viscosity among the tested gums. It appeared to heavily restrict granule swelling of the waxy maize starches, but it increased swelling of potato starch granules. Dry heating raised the paste viscosity of all the starch-gum mixtures tested, except the potato starchalginate mixture. The final viscosity at 50°C of a 7% paste was raised in all other starches by ≈500–1,000 cP by this treatment. The paste of waxy maize starch-gum products became opaque and shorter textured by the heat...
TL;DR: In this article, three spelt genotypes (Rouquin, Redoute, and HGQ Rouquin improved for gluten quality), each characterized by either high or low protein content, were processed to manufacture spaghetti, which was dried at both low (60°C) and high temperature (90°C), to assess the effects of flour properties and drying conditions on spelt pasta quality.
Abstract: Three spelt genotypes (Rouquin, Redoute, and HGQ Rouquin= Rouquin improved for gluten quality), each characterized by either high or low protein content, were processed to manufacture spaghetti, which was dried at both low (60°C) and high temperature (90°C) to assess the effects of flour properties and drying conditions on spelt pasta quality. Protein content in the spelt flour was considered low at ≈11.4% db and high at ≈13.5% db. Gluten properties, assessed by SDS sedimentation and gluten index values and by alveograph and farinograph parameters varied widely, ranging from poor for Redoute to very good for HGQ Rouquin. Pasta quality was assessed by determining color (L*, a*, and b* values), furosine, and cooking quality (stickiness, bulkiness, firmness, and total organic matter [TOM]). Furosine and color (a* and b* values) were significantly influenced by the intensity of the drying process. TOM and organoleptic judgement (OJ) showed that spelt pastas dried at low temperature, independent of th...
TL;DR: In this article, the influence of starch granule surface properties on durum wheat dough linear viscoelasticity was investigated, and surface interactions between starch granules and gluten were assessed using a model system.
Abstract: The contribution of starch to dough rheological properties has been largely overshadowed by the role of gluten, receiving much less attention in comparison. The influence of starch granule surface properties on durum wheat dough linear viscoelasticity was investigated, and surface interactions between starch granules and gluten were assessed using a model system. Proportions of starch were substituted in dough on a volume basis with an inert filler (glass powder) with a similar particle size range. The doughs were subjected to dynamic and creep measurements. Dough linear viscoelastic properties were weakened on substitution of starch with glass powder at ≤50% substitution, inferring a reduction in adhesion at the matrix-filler (starch and glass powder) interface with declining proportions of starch granules. Surface modification of starch granules or glass powder altered dough rheological properties, confirming the importance of starch granule surface characteristics and the nature of protein-sta...
TL;DR: In this article, the functional properties of various species and cultivars of lupin were studied for their effect as additives to baked products and their ability to provide foaming and emulsifying properties.
Abstract: The nutritional quality of various food products could be improved by supplementation with grain legumes to increase protein content and to improve the balance of essential amino acids. The lupin grain is a good candidate for this role, given its yield potential in a range of climatic environments and soil types. To establish the practicality of extending the use of lupins as food additives, the functional properties of various species and cultivars of lupin were studied for their effect as additives to baked products and their ability to provide foaming and emulsifying properties. Of the two lupin species that are commonly cultivated commercially, Lupinus albus showed the greater potential as a bread additive; loaf height and structure were maintained when lupin flour was substituted for wheat flour at levels up to 5%. This level of substitution offered the advantage of reducing mixing time. The detrimental effects at higher substitution levels appeared to be associated with the nonprotein compo...
TL;DR: The accumulation of transcripts for the major gluten storage proteins was assessed during grain development in wheat plants (Triticum aestivum L. "Butte 86" grown under seven controlled environments where temperature, water, and fertilizer conditions were varied after anthesis as mentioned in this paper.
Abstract: The accumulation of transcripts for the major gluten storage proteins was assessed during grain development in wheat plants (Triticum aestivum L. ‘Butte 86’) grown under seven controlled environments where temperature, water, and fertilizer conditions were varied after anthesis. Transcripts within the α-, γ- and ω-gliadin, low molecular weight glutenin subunit (LMW-GS), and high molecular weight glutenin subunit (HMW-GS) gene families followed similar patterns of accumulation throughout grain development under each environmental regimen. Under moderate daytime temperatures in plants that were well watered and fertilized, transcripts from all gene families were detectable by eight days postanthesis (8 DPA), were present at high levels until ≈34 DPA, and disappeared between 36 and 38 DPA. Under high temperature regimens, transcripts from all gene families appeared slightly earlier, but the time frame of accumulation was shorter. The presence or absence of postanthesis fertilizer did not alter the t...
TL;DR: The structural features of rice starch that may contribute to differences in the functionality of three long-grain rice cultivars were studied in this paper, where they were analyzed for milling quality, grain physical attributes, and starch structures and physicochemical properties.
Abstract: The structural features of rice starch that may contribute to differences in the functionality of three long-grain rice cultivars were studied. Dried rough rice samples of cultivars Cypress, Drew, and Wells were analyzed for milling quality, grain physical attributes, and starch structures and physicochemical properties. Drew was lower in head rice yield and translucency and higher in percentage of chalky grains compared with Cypress and Wells. Apparent amylose content (21.3–23.1%), crude protein (8.3–8.6%), and crude fat (0.48–0.64%) of milled rice flours were comparable, but pasting properties of rice flours as measured by viscoamylography, as well as starch iodine affinity and thermal properties determined by differential scanning calorimetry were different for the three cultivars. Drew had higher peak, hot paste, and breakdown viscosities, and gelatinization temperature and enthalpy. Molecular size distribution of starch fractions determined by high-performance size-exclusion chromatography s...
TL;DR: The importance of the amylopectin and amylose-to-amylophectin ratio in the gelation of highamylose maize starch was examined in this paper.
Abstract: The importance of the nature of the amylopectin and the amylose-to-amylopectin ratio in the gelation of high-amylose maize starch was examined by preparing gels of model systems using amylose (AM) from a high-amylose maize starch mixed with an amylopectin (AP): either wx starch, acid-hydrolyzed wx starch (AH-wx), ae wx starch, or wx β-limit dextrin. Mixtures of 7.5% starch in 20% dimethyl sulfoxide (DMSO) were examined by differential scanning calorimetry and dynamic oscillatory rheometry. Mixtures of 1.88 or 3.75% AM with the remainder either wx or AH-wx developed a measurable elastic modulus (G′) within one day, more quickly than for the corresponding AP without AM. Gels of AM with either wx or AH-wx starch developed a higher retrogradation enthalpy (ΔH) than corresponding AP without AM when the ΔH values were normalized to the amylopectin content. The G′ and ΔH of all gels containing ae wx did not change after one day. During heating of the gels to 80°C, most of the G′ at 25°C was lost, indica...
TL;DR: In this article, the physicochemical properties of starch were investigated for up to 5 min after heating, and their physicochemical property was investigated using sonication for mung bean, potato, and rice starch solutions (5%, w/w).
Abstract: Mung bean, potato, and rice starch solutions (5%, w/w) were sonicated for up to 5 min after heating, and their physicochemical properties were investigated. Alkaline viscosities, including the apparent and inherent viscosities of starches, decreased. The residues of the swollen starch granules after pasting and centrifugation were also reduced prominently by sonication. Average degree of polymerization did not change with sonication. The starch paste became more transparent, and the hot paste viscosity measured at 70°C decreased remarkably. Results indicate that changes in the physicochemical properties of starch were induced by the disruption of swollen granules rather than the breakage of glucosidic linkages with sonication.
TL;DR: The solvent retention capacity (SRC) profile is useful for studying flour components contributing to end-use functionality as discussed by the authors, and the method was modified to require only 0.2 g of ground wheat instead of 5 g of flour per SRC solvent.
Abstract: The solvent retention capacity (SRC) profile is useful for studying flour components contributing to end-use functionality. The method tests four different solvents with 5 g of flour each. Because of the amount of grain (30–40 g) typically needed to produce 20 g of flour for the SRC test, the method is not well-suited for assessing end-use quality of early generation breeding material, where grain quantities are limited. The method was therefore modified to require only 0.2 g of ground wheat instead of 5 g of flour per SRC solvent. The small-scale SRC results using whole meal had correlations of r = 0.86 for lactic acid, r = 0.85 for sodium carbonate, r = 0.78 for sucrose, r = 0.74 for sodium bicarbonate (the alkaline water retention capacity method) and r = 0.69 for water when compared with SRC values from full-scale tests using 5 g of flour. Overall, cultivars with SRC values at the extremes of the distribution were in the same ranked order for the small- and large-scale SRC test results. Howev...
TL;DR: A total of 162 doubled haploid (DH) lines were produced from a cross between Triticum aestivum L. "AC Karma" and line 87E03-S2B1 to study the genetic contribution of high molecular weight (HMW) glutenin subunits to gluten strength.
Abstract: A total of 162 doubled haploid (DH) lines were produced from a cross between Triticum aestivum L. ‘AC Karma’ and line 87E03-S2B1 to study the genetic contribution of high molecular weight (HMW) glutenin subunits to gluten strength. HMW glutenin subunit composition of each DH line was determined by SDS-PAGE. The population was grown in the field at one location in 1999 and at three locations in 2000. Gluten strength and dough mixing properties were measured by mixograph test and SDS-sedimentation test. Variance components were estimated for each measurement to determine the variability contributed by HMW glutenin subunits. Results indicated significant environmental impact on tested mixograph parameters, SDS-sedimentation volumes and grain and flour protein concentration. Significant main effects of Glu-1D loci encoded subunits were obtained for mixograph development time, energy to peak, slope after peak, and first minute slope. Lines containing 5+10 combination of subunits had higher values for ...
TL;DR: In this article, les travaux concernant la determination de la structure fine and des branchements de l'amylopectine sont presentes ici.
Abstract: Le fractionnement de l'amidon de mais donne de l'amylose, de l'amylopectine et un materiau intermediaire . L'amylopectine ne peut etre precipite par l'alcool isoamylique et le butanol. Les travaux concernant la determination de la structure fine et des branchements de l'amylopectine sont presentes ici.
TL;DR: In this paper, the effects of lipids and β-cyclodextrin (β-CD) on pasting properties of isolated rice starch with commercial rice starch were investigated.
Abstract: Lipids are known to generally affect starch properties but the effects of lipid structure and β-cyclodextrin (β-CD) on different starches has not been investigated. This study compared the effects of lipids and β-CD on pasting properties of isolated rice starch with commercial rice starch. Flour was defatted by Soxhlet extraction and deproteinated by alkaline protease digestion. Fatty acids, monopalmitin (MP), tripalmitin, lysophosphatidylcholine (LC), lysophophatidylethanolamine (LE), each added at 0.2 and 0.6% (starch db), and β-CD added at 2 and 6% (starch db) were tested. Pasting temperature (PT) increased with added phospholipid, particularly in the commercial starch, while all lipids except tripalmitin increased final viscosity (FV) and total setback (TSB). Breakdown (BKD) was mainly affected and increased by up to 39 RVU for fatty acids while decreasing by up to 80 RVU for other lipids in both starches. TSB doubled by the addition of 0.6% MP but decreased to onethird by 0.6% LE or LC. Addi...