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1.
Up to 15% modified potato starch (MPS) is often added into Korean instant noodle formulas to improve the cooking and eating quality. However, the addition of MPS leads to higher raw material costs. The effect of phosphate salts (PS) on Korean instant‐fried noodle pasting properties was investigated in this research. When 33% of total MPS in the regular Korean instant noodle formula was substituted by a small amount of PS (≤0.3%), the results clearly indicated that all the PS improved the pasting properties of noodle dough and ground instant‐fried noodle powder, especially the peak viscosity of the Rapid ViscoAnalyser (RVA) curves. However, the pasting temperature was affected little by PS except that tripotassium phosphate increased it significantly. The RVA results showed that the pasting properties of ground instant noodle powder were significantly improved when 33% of MPS was substituted by 0.300% dipotassium phosphate. Meanwhile, the pasting properties were close to those of the regular formula ground instant noodle powder when 33% of MPS was substituted by 0.030% monosodium phosphate or 0.300% disodium phosphate. Therefore, we suggest that MPS used in Korea instant‐fried noodle could be partially substituted by the blends of selected PS.  相似文献   

2.
Starch pasting properties and amylose content from 17 waxy barley lines (waxy gene originating from indigenous lines and an artificial mutant) were analyzed using rapid viscosity analysis (Rapid Visco Analyser [RVA]). Amylose contents varied from 0% (Shikoku‐hadaka 97) to 9.5% (Shikoku‐hadaka 96) compared with 30% for normal barley. Eight parameters were obtained from RVA profiles of these lines and correlation between each of these parameters and amylose content were evaluated. These parameters include pasting temperature (PT), peak viscosity (PV), temperature at PV, minimum viscosity (MV), final viscosity (FV), breakdown (BD), setback (SB), and time maintained at >80% PV (hot paste stability [HPS]). Significant correlations (0.64 and 0.61) were found between amylose content and FV and SB, respectively. High correlation (0.72) was found between amylose content and temperature at PV. HPS calculated from RVA profiles showed the highest correlation (0.79) to amylose content. Outer part of barley grains contained higher amounts of amylose than the inner part. There was a tendency that both PT and FV positively correlated to the amylose content of these parts.  相似文献   

3.
Mineral content, as determined and expressed by ash content, serves as an index of wheat flour quality for flour millers and food manufacturers who prefer flour of low mineral content, even though the significance of mineral content on the functional properties of wheat flour is not well understood. We explored whether minerals have any influence on the functional properties of wheat flour and product quality of white salted noodles. Ash, obtained by incinerating wheat bran, was incorporated into two hard white spring wheat flours and their starches to raise the total ash content to 1, 1.5, or 2%. Pasting properties were determined using a rapid visco analyzer (RVA). Addition of ash increased the peak viscosity of the flours in both water and buffer solution but did not affect the peak viscosity of starch. Wheat flours with added ash showed lower pasting temperature by approximately 10°C in buffer solution. Mineral extracts (15.3% ash) isolated from wheat bran, when added to increase the ash content of wheat flour and starch to 2%, increased the peak viscosity and lowered the pasting temperature of flour by 13.2–16.3% but did not affect the pasting properties of the isolated starch. The mineral premix also increased peak viscosity of wheat flour but not in starch. Added ash increased noodle thickness and lowered water retention of cooked noodles while it exhibited no significant effect on cooked noodle texture as determined using a texture analyzer.  相似文献   

4.
Genetic variation in the physical properties of sweet potato starch.   总被引:10,自引:0,他引:10  
Sweet potato starch, prepared from 44 genotypes adapted to Philippine conditions, showed wide variation and distinctly different pasting profiles in Rapid Visco-Analyzer (RVA) analysis at 11% and 7% starch concentration. At 11% starch concentration, the pasting profiles were type A, characterized by high to moderate peak with a major breakdown and low cold paste viscosity. At 7%, the pasting profile was generally type C, characterized by the absence of a distinct peak with none to very slight breakdown and high cold paste viscosity. However, differentiation among genotypes was better achieved from RVA pasting profiles at 11% starch concentration. Peak viscosity (PV) and hot paste viscosity (HPV) at 11% starch paste concentration had significant negative correlation with amylose content. PV, HPV, and setback ratio were significantly correlated to adhesiveness of the starch gel. Sweet potato starch generally had high swelling volume but low solubilities at 92.5 degrees C.  相似文献   

5.
Wheat starch is considered to have a low paste viscosity relative to other starches. Consequently, wheat starch is not preferred for many applications as compared to other high paste viscosity starches. Increasing the viscosity of wheat starch is expected to increase the functionality of a range of wheat flour-based products in which the texture is an important aspect of consumer acceptance (e.g., pasta, and instant and yellow alkaline noodles). To understand the molecular basis of starch viscosity, we have undertaken a comprehensive structural and rheological analysis of starches from a genetically diverse set of wheat genotypes, which revealed significant variation in starch traits including starch granule protein content, starch-associated lipid content and composition, phosphate content, and the structures of the amylose and amylopectin fractions. Statistical analysis highlighted the association between amylopectin chains of 18-25 glucose residues and starch pasting properties. Principal component analysis also identified an association between monoesterified phosphate and starch pasting properties in wheat despite the low starch-phosphate level in wheat as compared to tuber starches. We also found a strong negative correlation between the phosphate ester content and the starch content in flour. Previously observed associations between internal starch granule fatty acids and the swelling peak time and pasting temperature have been confirmed. This study has highlighted a range of parameters associated with increased starch viscosity that could be used in prebreeding/breeding programs to modify wheat starch pasting properties.  相似文献   

6.
Systematic studies were performed on the effect of the surfactant alkyl chain length (10–16 carbon atoms) and the head group charge/structure (anionic, cationic, nonionic) on the pasting properties of wheat flour and starch aqueous suspensions by means of a Rapid Visco Analyser (RVA). An excellent agreement was observed between the effect of surfactants on the onset temperature of the pasting process (PT) and the time to reach peak viscosity (tpeak) of wheat flour and wheat starch suspensions. Moreover, a correlation was found between the effect of different surfactants on these two parameters. With the exception of the cationic surfactants (alkyl trimethyl ammonium bromides), the effect of surfactants (alkyl sulfates, maltosides, monoglycerides, and sucrose esters) was found to be strongly dependent on the surfactant chain length. Shorter chain surfactants (C10–C12) induced an earlier pasting, while longer chain surfactants (C14–C16) had the opposite effect. The effect of surfactants on PT and tpeak of flour suspensions was enlarged when the surfactant concentration was increased from ≈1% to 15% (w/w) on a dry starch basis.  相似文献   

7.
Pasting profiles of selected starches were compared by using a Micro Visco‐Amylo‐Graph (MVA) and a Rapid Visco Analyser (RVA). Effects of cooking (heating/cooling) rate and stirring speed on starch pasting properties were examined. The pasting viscosity of a starch suspension (8%, w/w, dsb) was measured at a fast (6°C/min) and slow (1.5°C/min) cooking rate while being stirred at either 75 rpm or 160 rpm. The pasting temperatures (PT) of all starches were higher when measured at the fast cooking rate than those at the slow cooking rate, except for wheat measured by using the RVA. PT was also higher when measured at the slow stirring speed (75 rpm) than at the fast stirring speed (160 rpm) in both RVA and MVA. When stirring speed increased from 75 rpm to 160 rpm, peak viscosity of all starch pastes except potato decreased measured by using the RVA, but increased by using the MVA. In general, amylograms of these starches obtained by using the MVA showed less breakdown, but greater setback viscosity than did that obtained by using the RVA. Differences in starch pasting properties between MVA and RVA, measured at the same cooking and stirring rates, were attributed mainly to the difference in spindle structure.  相似文献   

8.
Some mutant wheat lines with low‐amylose content were grown in a field and greenhouse (15 or 20°C) to compare apparent amylose content and starch pasting properties. The apparent amylose content of flour and starch increased and starch pasting parameters as measured by a Rapid Visco Analyser (RVA) changed in the greenhouse (at cool temperatures) during seed maturation. Densitometric analysis of the protein band separated by electrophoresis suggested that the increase in amylose content by cool temperature was related to the amount of Wx‐D1 protein. This data suggests that the Wx‐D1 gene was responsible for these changes. In wheat starch from Tanikei A6099 and Tanikei A6598 at 15°C, the value of final viscosity and total setback was higher than that from the field. In wheat starch from Tanikei A6599‐4 (waxy mutant with stable hot paste viscosity), the peak viscosity temperature was higher and time maintained >80% of the peak was shorter at 15°C than that from the field. Genetic analysis using doubled‐haploid (DH) lines from a combination of Tanikei A6599‐4 and Kanto 118 (low‐amylose line) showed that apparent amylose content increased and the starch pasting curve and properties changed in waxy progenies similar to Tanikei A6599‐4.  相似文献   

9.
This study evaluated the effect of initial pH on percent of starch yield and pasting characteristics for a laboratory wet‐milling procedure. Four commercial hybrids, selected because they have significantly different starch yield values, were laboratory wet‐milled, and the pasting properties of the starch fractions were evaluated using a Rapid Visco Analyser (RVA). Percent starch yield (db) decreased when initial pH values were >4.0 but was unaffected by any lower initial pH values. The pasting properties of some of the selected hybrids were more sensitive to steepwater pH than others. There was an overall increase in peak, trough, and final viscosity as pH increased.  相似文献   

10.
优质小麦子粒淀粉组成与糊化特性对氮素水平的响应   总被引:1,自引:0,他引:1  
在大田条件下,选用3个不同类型优质小麦品种: 豫麦47(强筋品种)、山农8355(中筋品种)和豫麦50(弱筋品种),设置3个氮肥水平: 施N 0、15和30 g/m2,研究了小麦子粒淀粉的粒度分布、直支链淀粉组成、糊化特性及其对氮素水平的响应。结果表明,优质小麦子粒中淀粉粒的粒径分布范围为1~45 μm,其数目分布呈单峰或双峰曲线变化,体积和表面积分布均呈双峰曲线变化,峰谷位于10 μm处; 据此可将淀粉粒分为两种类型: A型大淀粉粒(10~45 μm)和B型小淀粉粒(1~10 μm)。优质小麦子粒淀粉粒组成存在显著的基因型差异。强筋品种豫麦47子粒中B型淀粉粒的比例较高,弱筋品种豫麦50子粒中A型淀粉粒的比例较高,中筋品种山农8355居中。施氮水平对优质小麦子粒中淀粉的粒度分布存在显著影响。在本试验条件下,随氮素水平的提高,强筋品种豫麦47子粒中A型淀粉粒的比例提高,而B型淀粉粒的比例下降; 增施氮肥后弱筋品种豫麦50和中筋品种山农8355子粒中B型淀粉粒的比例增大,而A型淀粉粒的比例降低,且前者变化的幅度较大。适量增施氮肥提高优质小麦子粒中的淀粉含量,氮肥用量进一步增大后,淀粉含量降低; 增施氮肥后优质小麦子粒中直链淀粉含量降低。增施氮肥对优质小麦子粒淀粉的糊化特性存在较大影响,且此影响的趋势因基因型和施氮量而异。其中强筋品种豫麦47表现为低谷粘度、最终粘度、反弹值、糊化温度和峰值时间提高,而高峰粘度和稀懈值降低; 当氮肥用量增大至30 g/m2时,糊化温度和峰值时间降低,而以粘度为单位的参数均提高。弱筋品种豫麦50表现为增施氮肥后,RVA参数呈下降趋势,与之相对应中筋品种山农8355的呈上升趋势。相关性分析表明,B型淀粉粒的数目、体积和表面积比例与高峰粘度和稀懈值存在显著正相关; 与低谷粘度、最终粘度和反弹值存在显著负相关。子粒中直链淀粉含量、支链淀粉含量和总淀粉含量与高峰粘度和稀懈值呈显著负相关,与低谷粘度、最终粘度、反弹值和峰值时间呈一定程度正相关; 直链淀粉相对含量与RVA特征参数之间的相关趋势与子粒中直链淀粉含量的趋势一致,但均未达显著水平。由此可以认为,氮肥通过调控小麦子粒中淀粉的直、支链组成和粒度分布而影响其糊化特性。  相似文献   

11.
The effects of ferulic acid and catechin on starch pasting properties were studied as part of an investigation into the structure and functionality of phenolics in starch‐based products. Commercial maize starch, starches from sorghum cultivars (SV2, Chirimaugute, and DC‐75), and the phenolic compounds ferulic acid and catechin were used in the investigation. Pasting properties were measured using rapid viscosity analysis. Ferulic acid and catechin (up to 100 mg each) were added to maize or sorghum starch (3 g, 14% mb) in suspensions containing 10.32% dry solid content. Addition of catechin resulted in pink‐colored pastes, whereas ferulic acid had no effect on paste color. Ferulic acid and catechin decreased hot paste viscosity (HPV), final viscosity, and setback viscosity of maize and sorghum starch pastes, but had no influence on the peak viscosity (PV) of the former. Both phenolics increased breakdown viscosity. Ferulic acid had greater influence on HPV, final viscosity, breakdown, and setback than catechin. Addition of catechin under acidic conditions (pH 3) decreased HPV, final viscosity, and setback of maize starch, but alkaline conditions (pH 11) slightly increased setback. Both acidic and alkaline conditions resulted in increased breakdown. Investigations on model‐system interactions between ferulic acid or catechin and starch demonstrated that phenolic type and pH level both significantly influence starch pasting properties, with ferulic acid producing a more pronounced effect than catechin. The significance of these interactions is important, especially in food matrices where phenolics are to be added as functional food ingredients.  相似文献   

12.
Flours from five spelt cultivars grown over three years were evaluated as to their breadbaking quality and isolated starch properties. The starch properties included amylose contents, gelatinization temperatures (differential scanning calorimetry), granule size distributions, and pasting properties. Milled flour showed highly variable protein content and was higher than hard winter wheat, with short dough‐mix times indicating weak gluten. High protein cultivars gave good crumb scores, some of which surpassed the HRW baking control. Loaf volume was correlated to protein and all spelt cultivars were at least 9–51% lower than the HRW control. Isolated starch properties revealed an increase in amylose in the spelt starches of 2–21% over the hard red winter wheat (HRW) control. Negative correlations were observed for the large A‐type granules to bread crumb score, amylose level, and final pasting viscosity for cultivars grown in year 1999 and to pasting temperature in 1998 samples. Positive correlations were found for the small B‐ and C‐type granules relative to crumb score, loaf volume, amylose, and RVA final pasting viscosity for cultivars grown in 1999, and to RVA pasting temperature for samples grown in 1998. The environmental impact on spelt properties seemed to have a greater effect than genetic control.  相似文献   

13.
The effects of four inorganic phosphates on the thermodynamic and pasting properties of whole wheat flour as well as color, cooking quality, textural properties, and structural characteristics of whole wheat noodles were studied. The addition of phosphates increased the gelatinization temperature and enthalpy of melting of starch in whole wheat flour. Rapid visco analysis showed that all phosphates significantly increased whole wheat flour peak viscosity and final viscosity. Moreover, the whole wheat noodles prepared with disodium phosphate, trisodium phosphate, and sodium tripolyphosphate (STPP) exhibited brighter appearance, and the use of STPP and sodium hexametaphosphate reduced the cooking loss of whole wheat noodles. Texture profile analysis of cooked noodles revealed that the addition of phosphates significantly decreased the hardness and slightly increased the springiness, cohesiveness, and resilience. The microstructure of whole wheat noodles showed a larger degree of connectivity of the protein network and coverage of starch granules in the presence of inorganic phosphates. The results suggested that inorganic phosphates exhibited substantial effects on improving the quality of whole wheat noodles. Of the four phosphates studied, STPP appeared to be the most effective one in improving the overall properties of whole wheat noodles when they were normalized to constant phosphate content.  相似文献   

14.
Flour properties of 25 Australian wheat cultivars were examined for their relationship to alkaline noodle quality. Rapid Visco Analyzer (RVA) analyses of flours showed that RVA breakdown and final viscosity determined in both water and dilute sodium carbonate were significantly related to the alkaline noodle firmness, elasticity, and surface smoothness. Flour swelling volume (FSV) of flours was negatively correlated with alkaline noodle firmness and elasticity, and positively correlated with surface smoothness of cooked noodles. Use of a dilute sodium carbonate solution led to overall increases in both paste viscosity and FSV. High FSV and low RVA final viscosity values were associated with both the softest noodles and with cultivars containing a null allele for granule-bound starch synthase on chromosome 4A. Flour protein content and SDS sedimentation volumes were significantly related to noodle texture. The relationship between protein content and noodle firmness was dependent on the Null4A status of the flours and suggested an interaction between starch and protein in determining noodle texture. Multiple regression analysis using flour protein and FSV accounted for 76% of the variation in alkaline noodle firmness. A speculative model of noodle structure was developed based on a concept of the cooked noodle as a composite material.  相似文献   

15.
The use of the Rapid Visco Analyser (RVA) for application in the screening of wheat breeding lines for starch quality and potential noodle quality has been limited by relatively low sample throughput. Current methods generally enable only 20–30 samples to be tested each day. This study sought to develop a more rapid time‐temperature profile that could be applied to whole meal samples. A profile that involved a total analysis time of 7.5 min/sample gave measurements of peak viscosity (PV) and breakdown (BD) on whole meal that were highly correlated with corresponding measurements obtained using a more conventional profile that had been applied to low‐extraction flours. BD and PV were also highly correlated with the total texture score of ramen (Chinese‐style alkaline noodles as manufactured in Japan), but only when 1 mM AgNO3 was used to eliminate the effects of α‐amylase.  相似文献   

16.
Starch was extracted from 14 sweetpotato genotypes from the Philippines. The Rapid Visco-Analyzer (RVA) viscoamylographs of the starches showed Type A pasting curves, characterized by a high pasting peak followed by a high degree of shear-thinning. The major difference among genotypes was in the sharpness of the peak, with some showing a very sharp peak while others showed a broad peak. This difference was related to time from onset of pasting to peak viscosity, and to stability ratio (holding viscosity/peak viscosity), which were also highly correlated (r = 0.84, P < 0.01) to each other. Stability ratio was also correlated to noodle firmness (r = 0.95, P < 0.01), rehydration (cooked weight) (r = -0.89, P < 0.01), and swelling volume of the starch (r = -0.62, P < 0.05). The amylose content was correlated significantly only to peak viscosity (r = -0.84, P < 0.01). Significant differences in texture and cooking quality of the starch noodles produced from the different genotypes was found. It was shown that the RVA viscoamylographs could be used to detect differences in pasting characteristics of sweetpotato starch which are related to quality of noodle produced.  相似文献   

17.
The starch of wheat (Triticum aestivum L.) flour affects food product quality due to the temperature-dependent interactions of starch with water during gelatinization, pasting, and gelation. The objective of this study was to determine the fundamental basis of variation in gelatinization, pasting, and gelation of prime starch derived from seven different wheat cultivars: Kanto 107, which is a partial waxy mutant line, and six near-isogenic lines (NILs) differing in hardness. Complete pasting curves with extended 16-min hold at 93°C were obtained using the Rapid Visco Analyser (RVA). Apparent amylose content ranged from 17.5 to 23.5%; total amylose content ranged from 22.8 to 28.2%. Starches exhibited significant variation in onset of gelatinization. However, none of the parameters measured consistently correlated with onset or other RVA curve parameters that preceded peak paste viscosity. Peak paste viscosity varied from 190 to 323 RVA units (RVU). Higher peak, greater breakdown, lower final viscosity, negative setback, and less total setback were associated with lower apparent and total amylose contents. Each 1% reduction in apparent or total amylose content corresponded to an increase in peak viscosity of about 22 and 25 RVU, respectively, at 12% starch concentration. Of the seven U.S. cultivars, the lower amylose cultivars Penawawa and Klasic were missing the granule-bound starch synthase (GBSS; ADPglucose starch glycosyl transferase, EC 2.4.4.21) protein associated with the Waxy gene locus on chromosome 4A (Wx-B1 locus). Kanto 107 was confirmed as missing both the 7A and 4A waxy proteins (Wx-A1 and Wx-B1 loci). The hardness NIL also were shown to be null at the 4A locus. Apparent and total amylose contents of prime starch generally corresponded well to the number of GBSS proteins; although the hardness NIL tended to have somewhat higher amylose contents than did the other GBSS 4A nulls. We concluded that reduced quantity of starch amylose due to decreased GBSS profoundly affects starch gelatinization, pasting, and gelation properties.  相似文献   

18.
We investigated the relationship between the protein content and quality of wheat flours and characteristics of noodle dough and instant noodles using 14 hard and soft wheat flours with various protein contents and three commercial flours for making noodles. Protein content of wheat flours exhibited negative relationships with the optimum water absorption of noodle dough and lightness (L*) of the instant noodle dough sheet. Protein quality, as determined by SDS sedimentation volume and proportion of alcohol‐ and salt‐soluble protein of flour, also influenced optimum water absorption and yellow‐blueness (b*) of the noodle dough sheet. Wheat flours with high protein content (>13.6%) produced instant noodles with lower fat absorption, higher L*, lower b*, and firmer and more elastic texture than wheat flours with low protein content (<12.2%). L* and free lipid content of instant noodles were >76.8 and <20.8% in hard wheat flours of high SDS sedimentation volume (>36 mL) and low proportion of salt‐soluble protein (<12.5%), and <75.7 and >21.5% in soft wheat flours with low SDS sedimentation volume (<35 mL) and a high proportion of salt‐soluble protein (>15.0%). L* of instant noodles positively correlated with SDS sedimentation volume and negatively correlated with proportion of alcohol‐ and salt‐soluble protein of flour. These protein quality parameters also exhibited a significant relationship with b* of instant noodles. SDS sedimentation volume and proportion of salt‐soluble protein of flours also exhibited a significant relationship with free lipid content of instant noodles (P < 0.01 and P < 0.001, respectively). Protein quality parameters of wheat flour, as well as protein content, showed significant relationship with texture properties of cooked instant noodles.  相似文献   

19.
Both cultivar and noodle composition and preparation have important effects on noodle quality. In this study, the effects of flour extraction rate (50, 60, and 70%), added water (33, 35, and 37%), and salt concentration (0, 1, and 2%, w/w) on color and texture of Chinese white noodle (CWN) were investigated using flour samples from five leading Chinese wheat cultivars. The five samples showed large variations in protein content, ash content, flour color, farinograph, and extensigraph parameters, and starch pasting properties. Analyses of variance indicated that cultivar, flour extraction rate, level of water addition, salt concentration, and the interactions had significant effects on color of raw noodle sheets and color and textural properties of CWN. Cultivar and water addition were more important sources of variation than flour extraction rate and salt concentration. The brightness (L*) and redness (a*) values of raw noodle sheets were significantly reduced and increased, respectively, as flour extraction rate increased from 50 to 70%, and noodle scores were slightly higher at flour extraction rates of 50%. Water addition showed different effects on raw noodle sheet color at 2 and 24 hr, and a significant improvement was observed for noodle appearance, firmness, viscoelasticity, smoothness, and total score as water addition increased from 33 to 37%. L* of raw noodle sheets, and firmness and viscoelasticity of cooked noodles, were significantly improved, but noodle flavor significantly deteriorated as salt concentration increased from 0 to 2%; 1% salt produced the highest noodle score. Thus, the recommended composition for laboratory preparation of CWN is 60% flour extraction, 35% water addition, and 1% salt concentration.  相似文献   

20.
This study evaluated the blending of flours made from an Ontario hard red winter wheat (HWF) and an Ontario soft red winter wheat (SWF) and compared it with a commercial standard noodle flour (control) made from Canadian Western Hard Red Spring wheat to assess the impact on white salted noodle‐making performance and texture of cooked noodles. Flour characteristics, gluten aggregation, and starch pasting properties were assessed with a farinograph, GlutoPeak tester, and Rapid Visco Analyzer, respectively. The machinability of dough was evaluated with an SMS/Kieffer rig attached to a TA.XT Plus texture analyzer. Tensile and bite tests of cooked noodles were also conducted. Blending HWF with standard noodle flour decreased gluten strength and dough extensibility linearly proportional to the blend ratio, whereas a curvilinear response from blending SWF with standard noodle flour was observed. HWF demonstrated more favorable pasting properties except for lower peak viscosity for noodle making than standard noodle flour. Below a 20% blend ratio with HWF, no significant changes were seen on dough extensibility, cooking loss, tensile properties, and bite testing parameters of cooked noodles. It can be concluded that blending HWF up to a 20% level caused no significant change in the processing properties of dough and cooked noodle quality. The results also showed that the GlutoPeak tester is a sensitive tool for evaluating gluten strength in wheat flour.  相似文献   

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