bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utilization of Hydroxypropylated Waxy Rice and Corn Starches in Korean Waxy Rice Cake to Retard Retrogradation
Authors: Han Jung‐Ah , Lee Bok‐Hee , Lim Wang Jin , Lim Seung‐Taik 
Published: June 2007

ABSTRACTA traditional waxy rice gel cake in Korea, Injulmi, was prepared with hydroxypropylated waxy rice and corn starches (molar substitutions 0.13 and 0.11, respectively), and the textural and retrogradation characteristics of the cake were compared with a conventional cake made of waxy rice flour. In the pasting viscogram, hydroxypropylated starches exhibited reduced pasting temperatures, but increased peak viscosities compared with the unmodified starches. Under differential scanning calorimetry, the Tg′ and ice melting enthalpy of the starch gel cakes were reduced by hydroxypropylation, which indicated that the modified starches had higher water‐holding capacity than the unmodified starches. The degree of retrogradation, as measured by the hardness of the gel cake and the melting enthalpy, was significantly reduced by hydroxypropylation and hydroxypropylated waxy rice starch was more effective in retarding the retrogradation than hydroxypropylated waxy corn starch
Effect of Different Enzymes on the Textural Stability of Shelf‐Stable Bread
Authors: Barrett Ann H. , Marando Gina , Leung Henry , Kaletunç Gönül 
Published: June 2007

ABSTRACTThree enzyme systems (2 amylase‐based and 1 protease‐based) were tested in shelf‐stable bread to determine effectiveness in preserving texture during storage for eight weeks. Each enzyme was tested in formulations without glycerol or with 6% glycerol. Bread samples were analyzed to determine physical properties (crumb density, crust‐to‐crumb ratio, rate of moisture distribution from crumb to crust), mechanical properties (modulus, and a parameter [C1] describing resistance to high levels of deformation obtained by fitting stress‐strain data to a three‐parameter function), and thermal properties (thermal stability and enthalpy of transitions) as a function of storage time. Mechanical properties were further analyzed to predict asymptotic firmness. Bread firmness after storage as evaluated in terms of modulus and C1 were lower in all enzyme‐added systems, the effect of protease being the most significant. Enzymes had less effect on glycerol‐containing systems with no apparent trend. The breads had complex thermal behavior and exhibited multiple transitions. Both amylase preparations in the presence of glycerol reduced the amount of starch recrystallization.
Rapid Quality Assessment of Wheat Cultivars Registered in Poland Using the 2‐g Mixograph and Multivariate Statistical Analysis
Authors: Dobraszczyk B. J. , Salmanowicz B. P. , Ługowska B. , Chełkowski J. 
Published: June 2007

ABSTRACTBaking and 2‐g mixograph analyses were performed for 55 cultivars (19 spring and 36 winter wheat) from various quality classes from the 2002 harvest in Poland. An instrumented 2‐g direct‐drive mixograph was used to study the mixing characteristics of the wheat cultivars. A number of parameters were extracted automatically from each mixograph trace and correlated with baking volume and flour quality parameters (protein content and high molecular weight glutenin subunit [HMW‐GS] composition by SDS‐PAGE) using multiple linear regression statistical analysis. Principal component analysis of the mixograph data discriminated between four flour quality classes, and predictions of baking volume were obtained using several selected mixograph parameters, chosen using a best subsets regression routine, giving R2 values of 0.862–0.866. In particular, three new spring wheat strains (CHD 502a‐c) recently registered in Poland were highly discriminated and predicted to give high baking volume on the basis of two mixograph parameters: peak bandwidth and 10‐min bandwidth.
Accumulation of γ‐Aminobutyric Acid in Giant‐Embryo Rice Grain in Relation to Glutamate Decarboxylase Activity and Its Gene Expression During Water Soaking
Authors: Liu L. L. , Zhai H. Q. , Wan J.‐M. 
Published: June 2007

ABSTRACTGlutamate decarboxylase (GAD) is the rate‐limiting enzyme for γ‐aminobutyric acid (GABA) synthesis. However, the relationship of GABA accumulation, GAD activity, and its gene expression in rice grain during water soaking is unknown yet. We assessed the role of GAD activity and its gene expression to GABA accumulation after the rice grain was soaked in water for 0, 1, 2, 4, 8, 16, and 32 hr. The results showed a continuous accumulation of GABA in steeped embryo, embryo‐less brown rice, and complete brown rice, respectively. Among them, embryo of brown rice had the maximal accumulation. The activity of GAD was gradually increasing during water soaking, and the enzyme activity was significantly higher in the embryo than in either the embryo‐less brown rice or whole brown rice. The results further indicated that the activity of GAD was markedly stimulated by 0.5 mmol/L of Ca2+, whereas it was almost completely inhibited by 1 mmol/L of Hg2+. Accordingly, the content of GABA in embryo paralleled the activity of GAD treated with Ca2+ or Hg2+. To measure the expression of three GAD homologous genes in steeped rice grain, a RT‐PCR method was developed using the housekeeping gene Actin as the control. Gene expression studies demonstrated differential expression patterns of the three GAD transcripts: OsGAD1, 2 and 3 in brown rice. These results suggested that the accumulation of GABA in rice grain could be attributed to the increase of OsGAD transcripts.
Granule‐Bound Starch Synthase I (GBSSI) in Quinoa (Chenopodium quinoa Willd.) and Its Relationship to Amylose Content
Authors: Lindeboom N. , Chang P. R. , Tyler R. T. , Chibbar R. N. 
Published: June 2007

ABSTRACTThe amylose concentration in starch from 16 quinoa (Chenopodium quinoa Willd.) genotypes grown under identical conditions was 4–20%. Based on the amylose content, a selection of six genotypes was made. Starch granule‐bound proteins were extracted from six genotypes and analyzed using denaturing gel electrophoresis. Two major polypeptides with apparent molecular masses of 56 and 62 kDa were present in all genotypes. Both were identified as granule‐bound starch synthase I (GBSSI) using immunoblot analysis and internal peptide sequencing. The content of the two GBSSI isoforms in starch granules from the six genotypes, as determined by densiometry of the peptide bands, was positively correlated with the concentration of amylose in starch from mature seed. Starch synthase activity in developing seed was positively correlated to starch concentration in seed and amylose concentration in starch during seed development.
Evaluation of Operating Conditions for Surface Lipid Extraction from Rice Using a Soxtec System
Authors: Matsler A. L. , Siebenmorgen T. J. 
Published: June 2007

ABSTRACTThe degree of milling (DOM) of rice is a measure of how well the germ and bran layers are removed from the surface of rice kernels during milling. Because the majority of rice kernel lipids are found on the surface, measuring the surface lipid content (SLC) of rice after milling may be one way to quantify the DOM of rice. While there are several methods to measure the lipid content (LC) of rice, there is not an established standard method for determining the SLC of milled rice. The objective of this study was to evaluate the primary operating variables of a Soxtec apparatus in measuring the SLC of milled rice. This was accomplished by varying the preextraction drying, boiling, rinsing, and postextraction drying durations, as well as the solvent used for extraction, to achieve the maximum extraction of lipids from rice. Experiments were performed on stored Oryza sativa L. ‘Cypress’ and ‘Bengal’ rice milled for 10, 30, and 60 sec. Results showed that durations of 1 hr of preextraction, 20 min of boiling, 30 min of rinsing, and 30 min of postextraction drying provided the maximum lipid extraction from milled head rice with petroleum ether. Of the three solvents tested, petroleum ether, and ethyl ether yielded similar extraction results.
Microbial Transglutaminase as a Tool to Restore the Functionality of Gluten from Insect‐Damaged Wheat
Authors: Bonet A. , Caballero P. A. , Gómez M. , Rosell C. M. 
Published: June 2007

ABSTRACTIn some wheat‐growing countries, considerable quantities of commercial wheat are rendered unusable in standard baking because of preharvest damage of the grain by protease‐injecting bugs. In the present study, we studied the ability of transglutaminase (TG) treatment of damaged wheat flour to return the functionality of the gluten network. To confirm the TG cross‐linking, the degree of protein hydrolysis, the amount of free thiol groups, and the electrophoresis properties of glutenin subunits were determined. The effectiveness of the TG treatment on insect‐damaged wheat was analyzed by measuring the dough mixing behavior and the gluten quality. A decrease in the degree of hydrolysis (or free amino groups), a reduction in thiol group concentration, and a decrease of extractable high molecular weight glutenin subunits (HMW‐GS) (measured by high‐performance capillary electrophoresis) confirmed the protein cross‐linking catalyzed by TG, the simultaneous formation of disulfide bonds by the proximity of the cross‐linked polypeptide chains, and the formation of aggregates of high molecular weight. The TG treatment of the damaged wheat flour led to a recovery of the consistograph parameters and gluten index value, and the covalent nature of the bonds ensured the stability of the protein changes.
Effect of Composition of Feed Model Systems on Pellet Quality: A Mixture Experimental Approach. II
Authors: Cavalcanti Walker B. , Behnke Keith C. 
Published: June 2007

ABSTRACTThe quality of pelleted feeds is dependent on several variables among which formulation is recognized as having the heaviest influence. An experiment was conducted to investigate the functional properties of feed ingredient components when these ingredients were blended at different proportions on the physical quality of pelleted feeds as measured by the pellet durability index (PDI). Thirteen treatments consisting of different inclusion levels of corn, soybean meal, and soybean oil were designed and a total of 18 batches manufactured, processed, and tested for PDI. Three‐dimensional plots were used to depict the relationships between composition of the formulations and PDI. Results showed only a weak dependence of the response on the starch levels in the formulas and the degree of starch gelatinization. Protein, especially from soybean meal, had a positive effect on PDI, whereas a strong negative effect was observed following fat inclusion in the mixer at levels >6.5%. Empirical equations devised by multiple regression analysis adequately predicted PDI of verification batches.
Alkaline‐Carbonate Noodles from Hard Winter Wheat Flours Varying in Protein, Swelling Power, and Polyphenol Oxidase Activity
Authors: Zhao L. F. , Seib P. A. 
Published: June 2007

ABSTRACTThe effects of wheat protein and starch on yellow‐alkaline noodles have not been fully clarified. Twenty‐four hard winter wheats with varying protein, hot‐water swelling power (SP95), and polyphenol oxidase (PPO) activity were milled into long‐patent and short‐patent flours. Protein, SP95, and PPO activity in the 48 flours were 8.2–12.9%, 16.2–24.1 g/g, and 80–157 ΔA480/mg of protein/min, respectively. Lightness of raw noodles declined with increasing protein and PPO levels but yellowness decreased and then increased. Tensile force to break the cooked noodles was positively correlated with SP95 and protein. Compression (50%) force of noodles made from flour with high SP95 ≈21 g/g, averaged ≈20% below those made from low SP95 ≈17 g/g of flour. Compression force was measured in the long dimension of a single noodle strand using a rectangular probe. The instrumental measurements suggest that alkaline noodles made from a single‐null partial‐waxy wheat with medium SP95 ≈19.9 g/g will have a tender bite and a cohesive texture compared with those from a low SP95 wheat with a hard bite and fracturable texture. Furthermore, alkaline noodles from a double‐null partial‐waxy wheat with high SP95 will have an extra soft bite unless flour protein is above ≈12.5%. Hard‐white, dual‐purpose wheat should have a low level of PPO and, depending on the preferred noodle‐eating texture, a low to medium SP95 level. Such wheats with medium protein levels (11–12%) are well suited for alkaline noodles because of improved color and surface smoothness, whereas the same wheats with 12–13% protein are well suited for bread. Wheats with medium SP95 also reduce cooking loss and increase cooked yield.
Studies of Partial Amino Acid Sequences of γ‐40k Secalins of Rye
Authors: Gellrich Claudia , Schieberle Peter , Wieser Herbert 
Published: June 2007

ABSTRACTThough γ‐40k secalins are a major protein type within rye storage proteins, total amino acid sequences are not as well known as the gluten proteins of wheat. Well‐reputed structural features such as amino acid compositions and molecular masses indicated a close relationship between γ‐40k secalins and γ‐gliadins of wheat, but the degree of homology of amino acid sequences and the positions of intramolecular disulfide bonds are unknown. Therefore, two major components of γ‐40k secalins (R1, R2) were analyzed for partial amino acid sequences. The R1 and R2, derivatized with 4‐vinylpyridine, were isolated from the prolamin fraction of rye cultivar Danko by means of a two‐step RP‐HPLC on C18 silica gel. The proteins were digested in parallel with trypsin and thermolysin, and the partial hydrolyzates were separated by RP‐HPLC. Simultaneous measurement of UV absorbance at 210 and 254 nm allowed the detection of all peptides eluted as well as the specific detection of pyridylethylated cysteine peptides. Isolated peptides were characterized by sequence analysis, and in parts by mass spectrometry, and assigned to known sequences of γ‐gliadins. The results demonstrated that the N‐terminal domain of R1 and R2 remained undigested after tryptic hydrolysis; they were in agreement with the N‐terminal domain of γ‐gliadins in their molecular masses and in the absence of cysteine residues. Most of the isolated peptides originated from the C‐terminal domains, they covered 83% (R1) and 77% (R2), respectively, of the C‐terminal domain of a known γ‐gliadin (clone pW1020). Comparison of R1 and R2 revealed differences only in a few sequence positions. The degree of homology between the C‐terminal domains present in γ‐40k secalins and γ‐gliadins was ≈85%. All eight cysteine residues of γ‐gliadins were found in R1 and R2 sequences. Remarkably, sequences close to corresponding cysteine residues were identical for γ‐40k secalins and γ‐gliadins. Therefore, it can be assumed that the positions of intramolecular disulfide links are homologous.
Effect of Microwave Heating of Kafirin on the Functional Properties of Kafirin Films
Authors: Byaruhanga Yusuf B. , Erasmus Corinda , Taylor John R. N. 
Published: June 2007

ABSTRACTTo improve the functional properties of cast kafirin films, dry kafirin, extracted with an aqueous ethanol‐based solvent at 70°C, was microwave‐heated. No effect on film tensile properties was found. Two strategies were employed to improve the effect of microwaving: extraction of kafirin using an aqueous tert‐butanol‐based solvent at ambient temperature to minimize temperature‐induced denaturation and wetting the kafirin to increase its dielectric properties. Microwave heating this kafirin to 90 or 96°C and holding for 1–2 min more than doubled maximum tensile strength and Young's modulus, and decreased strain by about one‐third compared with films made from nonmicrowaved kafirin. Film water vapor permeability was reduced by at least one‐third. Digestibility of microwaved kafirin and films was also substantially decreased, and film biodegradability was slowed slightly. Microwave heating gave a film microstructure with fewer and smaller size pores. SDS‐PAGE showed microwave‐induced intermolecular cross‐linking of the kafirin monomers, which was possibly responsible for the modification of film properties. Microwave heating of kafirin can be used to modify kafirin film properties, but the kafirin must be microwaved wet and be as close as possible to its native state.
SME‐Arrhenius Model for WSI of Rice Flour in a Twin‐Screw Extruder
Authors: Lei Hanwu , Fulcher R. Gary , Ruan Roger , van Lengerich Bernhard 
Published: June 2007

ABSTRACTWe have modeled a rice extrusion process focusing specifically on the starch gelatinization and water solubility index (WSI) as a function of extrusion system and process parameters. Using a twin‐screw extruder, we examined in detail the effect of screw speed (350–580 rpm), barrel temperature, different screw configurations, and moisture content of rice flour on both extrusion system parameters (product temperature, specific mechanical energy [SME], and residence time distribution [RTD]) and extrudate characteristics (expansion, density, WSI, and water absorption index [WAI]). Changes in WSI were monitored to reveal a relationship between the reaction kinetics during extrusion and WSI. Reaction kinetics models were developed to predict WSI during extrusion. WSI followed a pseudo first‐order reaction kinetics model. It became apparent that the rate constant is a function of both temperature and SME. We have developed an adaptation of the kinetic model based on the Arrhenius equation that shows better correlations with SME and distinguishes data from different screw configurations. This adaptation of the model improved predictability of WSI, thereby linking the extrusion conditions with the extruded product properties.
Classifying Paddy Rice by Morphological and Color Features Using Machine Vision
Authors: Liu Chang‐Chun , Shaw Jai‐Tsung , Poong Keen‐Yik , Hong Mei‐Chu , Shen Ming‐Lai 
Published: June 2007

ABSTRACTFrom five paddy rice cultivars grown in Taiwan and harvested in the summers of 1997, 1998, and 1999, five calibrated models were established by backpropagation neural network program through different morphological and color features selection for classifying paddy rice harvested in the summer of 2000. With 60 features, the average classification rates of Model 1 and Model 5 were 92 and 99.8%, respectively. With the most effective 50 features, by loading in the first principal component, the average classification rate of Model 2 was 90.0%. With 35 features selected from the correlation coefficient matrix, the average classification rate of Model 3 was 91.0%. With the most effective 20 features of area, area/perimeter, 48th width, shape factor, maximum length/maximum width, average intensity of blue, maximum length, average intensity of green, 47th width, 50th width, average intensity of red, 1st width, 19th width, 5th width, 6th width, 29th width, perimeter, 46th width, 42nd width, and 4th width based on the contribution of the training model, the average classification rate of Model 4 was 91.8% and would be recommended for classifying five paddy rice cultivars of set trading prices because it required fewer features and held a stable classification rate.
Evaluation of Liquid Nitrogen Freeze Drying and Ethanol Dehydration as Methods to Preserve Partially Cooked Starch and Masa Systems
Authors: Yglesias Roxana , Jackson David S. 
Published: June 2007

ABSTRACTPreservation of starch structure/properties, including structures formed during partial or complete cooking, are important when the impact of processing conditions is being studied. Two preservation techniques used to study changes in starch during thermal‐mechanical processing are commonly cited in the literature: 1) rapid freezing followed by lyophilization, and 2) a dehydration procedure using alcohols. A comparative determination on how these methods affect various starch structures has not been widely reported. Corn starch samples were collected from the Rapid Visco‐Analyser (RVA) at 3 min (swollen granules, 30°C), at the top of the pasting peak (gelatinized granules, 95°C), at the bottom of the trough (dispersed polymers, 95°C), and a completed RVA sample stored for 120 hr at 4°C (retrograded starch). Samples of masa were obtained by nixtamalizing corn. Differential scanning calorimetry (DSC) endotherms of starch and masa, and X‐ray diffraction (XRD) patterns of masa were evaluated after being preserved by alcohol‐ or freeze‐drying. No significant differences (P > 0.05) between methods were found for onset, end, and peak temperatures (°C), enthalpy (J/g) and % relative crystallinity in any of the samples analyzed. Liquid nitrogen freeze‐drying and ethanol dehydration are both effective methods of preserving various starch systems for structural changes detectible by DSC and XRD; freeze‐drying is generally less expensive and time‐consuming.
Molecular Level Protein Composition of Flour Mill Streams from a Pilot‐Scale Flour Mill and Its Relationship to Product Quality
Authors: Sutton K. H. , Simmons L. D. 
Published: June 2007

ABSTRACTFlour mill streams prepared from two Australian and two New Zealand wheat cultivars using a pilot‐scale roller mill were analyzed for rheological and baking quality characteristics and for protein composition using size‐exclusion HPLC. Differences in mill stream protein composition, on an industrially relevant scale, and the relationships between the distribution of proteins (and their degree of thiol exposure) and the technological quality of the flour mill streams were examined. Consistent, significant differences were observed in the physicochemical and processing characteristics of the flour streams. Between mill streams, changes in the quantities of the storage protein groups were more marked than for nonstorage protein groups. Changes in protein composition differed between the break and reduction stream flours. In contrast, the degree of exposure of thiol groups on the various protein groups followed different patterns between mill streams. Numerous significant relationships were observed between dough mixing and product baking tests and the composition and thiol exposure state of the various protein classes. These relationships are discussed in context of manipulating the processing quality of flour‐based products using mill streaming. A possible role for exposed thiol groups on storage proteins in the phenomenon of flour “aging” is suggested.
Oat Grain/Groat Size Ratios: A Physical Basis for Test Weight
Authors: Doehlert D. C. , McMullen M. S. , Jannink J.‐L. 
Published: June 2007

ABSTRACTMarket value of oat grain is largely determined by test weight or bulk density, yet little is known of the physical basis for test weight in oats. We have hypothesized that a larger sized groat relative to the oat grain (the kernel with the hull) would generate higher test weight oats because the groat is the densest structure in the oat grain. We tested this by measuring oat grain size and oat groat size by digital image analysis for 10 genotypes grown in 10 environments. We also measured other physical characteristics of the oats grains and groats including mean grain and groat mass, test weight, and groat percentage. We found that the groat/ grain size ratio was highly correlated with test weight. Because the oat grain image area was nearly twice that of the groat, we suggest that there are significant amounts of empty space within the oat hull, which detracts from test weight. We also found that oat groat size distributions, like oat grains, fit bimodal distributions better than normal distributions.