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1.
Octenyl succinate starches are commonly used as emulsifiers and texturizing agents in many food-systems. Rice, tapioca, corn, wheat and potato starches were modified with octenyl succinic anhydride (OSA) at 3% level. Structural characterization, molecular weight, starch digestibility and physical properties of starch granule stabilized emulsions were studied for modified starches. Modified potato (0.022) and wheat (0.018) starches had the highest and lowest degrees of OSA substitution, respectively. For all starches, amylose and amylopectin molecular mass was significantly (P < 0.05) lower for OSA starches. OSA modification may have hydrolyzed the small amylose and amylopectin chains, or caused rearrangement of the starch molecules. Although the starch modification improved emulsification properties, botanical source showed more influence on this parameter. Overall, botanical source had more influence on functional properties than degree of substitution. Further studies on OSA group distribution and fine molecular structure of amylopectin and relationship with functional properties will be important.  相似文献   

2.
This work investigated the effect of modified tapioca starch and xanthan gum on dough viscoelasticity and texture stability during storage at 4 °C of starch sheets for Chinese shrimp dumplings. Hydroxypropylated starch and hydroxypropylated-crosslinked starch were used to substitute for tapioca starch in the control formulation, and xanthan gum was added to adjust the formulation. During storage, texture of the control became firmer due to amylopectin retrogradation confirmed by differential scanning calorimetry and X-ray diffraction. Conversely, gel sheets containing modified starches showed less texture change. Dough viscoelasticity of the formulations substituted by hydroxypropylated starch were much softer and easier to deform than that of the control one. Dough with hydroxypropylated-crosslinked starch was, however, stiffer and more strain-resistant. Moreover, the formulation comprising the mixture of both types of modified starches and xanthan gum gave dough viscoelasticity similar to that of the control, and provided gel sheet the least texture change. Consequently, this modified formulation could be beneficial for the application of frozen/chilled dumpling wrappers.  相似文献   

3.
Native maize starches containing amylose are used for manufacturing gels in food technology at concentrations of about 7%. Depending on the pasting conditions chosen, several hours may be required for the final consistency to be attained. For this reason the influence of hydrocolloids was investigated with economic factors dictating an effective concentration of approximately 5% in terms of the pure starch. The gelation process was monitored quantitatively by means of rheomechanical oscillation measurements in the linear viscoelastic range. The substances investigated were polysaccharides with chemically similar structures and classified as safe under foodstuff regulations: guar gum, locust bean gum, x-carrageenan, t-carrageenan, xanthan and carboxymethylcellulose (CMC). The gelation process can be significantly accelerated by a range of hydrocolloids, with the effect decreasing as follows: CMC > locust bean gum > guar gum > x-carrageenan > xanthan. The mixtures achieved between 45% and 80% of the final gelation stability of pure starch of 100Pa. The gelation process is clearly retarded by the hydrocolloid t-carrageenan. With the aid of the rheological data it is possible to correlate the influence of the hydrocolloids on the process of self-aggregation and also on the resulting viscoelastic properties of the mixed gels with one another. In terms of a molecular interpretation it is possible to distinguish between exclusion effects and specific interactions in the functioning of the hydrocolloids.  相似文献   

4.
Native and acid‐hydrolyzed wx corn starches were modified by octenyl succinic anhydride (OSA) in aqueous slurry systems. The characteristics of the modified wx corn starches and their effects on chicken meat sausages were evaluated by means of FT‐IR, rapid visco analyser, SEM, and texture profile analysis. FT‐IR spectroscopy indicated that the ester carbonyl groups in the OSA modified native and acid‐hydrolyzed starches were characterized at 1725 cm−1. The process of OSA modification could achieve starch derivatives, which had higher viscosities, better paste clarity and freeze–thaw stability than the native counterparts. Texture results showed that the hardness, springiness, cohesiveness, and chewiness of the sausage increased as OSA‐H0 was added (p < 0.05). SEM revealed that the sausages with native wx corn starch had larger and uneven pores, while it was comparatively compact for the sausages with OSA starches. The OSA modified wx corn starch offered a great potential to be used in meat products to enhance textural quality.  相似文献   

5.
Response surface methodology was used to predict sensory attributes of a nongluten pasta and develop response surface plots to help visualize the optimum region. Optimum regions of xanthan gum, modified starch, and locust bean gum were selected by overlapping the contour plots of sensory properties of nongluten pasta as compared with the control pasta. The formula of nongluten pasta that possessed the most desirable properties was xanthan gum at 40 g, modified starch at 35 g, locust bean gum at 40 g, tapioca starch at 113 g, potato starch at 57 g, corn flour at 250 g, and rice flour at 50 g. The quality of nongluten pasta could be improved by using different levels of nongluten starches and flours, and nonstarch polysaccharides.  相似文献   

6.
Qingjie Sun  Fumei Si  Liu Xiong  Lijun Chu 《Food chemistry》2013,136(3-4):1421-1425
Corn starch, potato starch, pea starch 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 h at 130 °C. Effects of the dry heating on paste viscosity (RVA), microstructure and thermal properties were examined. Dry heat treatment with ionic gums reduced the pasting temperature of the three starches. Heating with xanthan increased the paste viscosity of corn and potato starch. With heat treatment, the paste viscosity of all the starch-sodium alginate mixtures decreased. Heating with CMC increased the paste viscosity of potato starch, but decreased that of corn and pea starch. After dry-heating, To, Tp and Tc of potato starch with ionic gums decreased significantly. SEM of potato starch with CMC showed that the gel structure got compacter after drying-heating. Heat treatment obviously improved the functional properties of the three starches.  相似文献   

7.
《LWT》2003,36(5):475-481
Yam tubers (Dioscorea alata) are a non-traditional starch source that could be used as food ingredient. The stability of yam starch pastes (6/100 g suspension) submitted to different pH conditions during gelatinization and the effect of hydrocolloids addition (guar and xanthan gums) on starch syneresis under refrigeration were analyzed. Changes in pH (3, 5, 6) or the addition of gums (0.1–0.5/100 g suspension) did not affect the starch gelatinization temperature nor the gelatinization enthalpy as determined by differential scanning calorimetry. Rheological behavior was characterized by amylograph profiles and oscillatory rheometry. Amylograms showed that yam starch pastes maintained a high viscosity under heat treatment and mechanical stirring in neutral to slightly acidic conditions. Brabender viscosity increased when gums were added; the effect of guar gum on viscosity was more marked than that of xanthan gum. During refrigerated storage exudate production was observed of pastes without gums. Xanthan gum, at a concentration of 0.5/100 g suspension, showed higher effectiveness than guar gum to reduce exudate production during refrigerated storage. The addition of hydrocolloids could allow yam starch to be used in foods requiring low temperatures.  相似文献   

8.
The aim of the study was to define the influence of selected nonstarch polysaccharides (guar gum, xanthan gum and arabic gum) on several rheological properties of triticale starch pastes/gels, at constant polysaccharide concentration (6.5 g/100 g). These included pasting characteristics, flow curves at 50 °C and mechanical spectra at 25 °C. It was found that the presence of a gum in a system modified the rheological properties of triticale starch gels/pastes, depending on the type and concentration of the gums. In the case of guar and xanthan gums, higher pasting viscosity was observed and the shear stress was increased compared with native starch. The presence of guar gum reduced the degree of thixotropy hysteresis, negative values for this being found for systems with xanthan in spite of their shear‐thinning behaviour. Systems containing arabic gum displayed lower values of pasting and flow viscosity. The type and concentration of gums added to the polysaccharide influenced the viscoelastic properties of the gels.  相似文献   

9.
The flow properties of the fluid portion of fruit fillings were assessed to investigate the effects of gums. Results indicated that the shear rate–shear stress relations of the fluid portion of commercial fruit fillings and the model fillings made of waxy corn starch, fructose, citrate buffer, and a gum which could be guar gum, locust bean gum, CMC, xanthan gum or κ-carrageenan, fit well into the Herschel–Bulkley equation for pseudoplastic fluids. The fluid portion of the commercial fruit fillings was characterized with a yield stress between 39–51 Pa, a consistency index between 52–104 Pa·sn, and a flow index (n) around 0.4. In addition, the shear rate–shear stress relations could be fitted into a modified Herschel–Bulkley equation with a flow index fixed at 0.4. Addition of guar gum, locust bean gum and CMC increased while xanthan gum and κ-carrageenan decreased the consistency and flow indices in the modified Herschel–Bulkley equation. The effect of gum addition on the apparent viscosity of model fillings varies with the type of gum, amount of addition, and shear rate.  相似文献   

10.
The effect of starch chemical modifications and hydrocolloids on the proportion of freezable water in starch gels at various moisture contents was studied. The proportion of freezable water increased with moisture content, from less than 6.1% to 84.9% (w/w) of the water fraction between 30% and 70% moisture content (wet weight basis, wwb). A transition between limited and excess water conditions was identified in the range 30‐40% moisture content (wwb), whereby the proportion of freezable water markedly increased from 6.1% to 40.4% (w/w) of the water fraction, in the case of the non‐modified starch control. At 30 and 40% moisture content (wwb), gels made of acetylated starch and hydroxypropylated starch had a significantly lower amount of freezable water than the control, in particular at 40% moisture content (wwb) the amount of freezable water was reduced from 40.4% to 15.3‐25.7% (w/w) of the water fraction. In systems with 50% moisture content (wwb) or higher, modified starches did not show a significant reduction in freezable water compared to the control. Two hydrocolloids, xanthan and carboxymethyl cellulose (CMC) used in a 40% moisture content (wwb) starch system significantly reduced freezable water from 40.4% to 23.9‐24.1% of the water fraction (w/w), at a hydrocolloid: starch ratio of 1:14 (w/w). The linear decrease in the freezable water proportion with xanthan and CMC concentration pointed to the absence of interactions between the starch and hydrocolloid fractions. Therefore, combinations of hydroxypropylated or acetylated starches and xanthan or CMC may be used to control freezable water, particularly in frozen food products with moisture contents around 40% (wwb).  相似文献   

11.
A range of carbohydrates including modified starches and short‐chain fatty acid esters of di‐, tri‐, tetra‐ and polysaccharides were subjected to an in vitro fermentation using human‐derived faecal bacteria. The production of the short‐chain fatty acids (SCFAs) acetate, propionate and butyrate was monitored at 6, 12, 24 and 36 h for all substrates; however, it was found that the proportions of acids produced were reasonably constant after 6 h. Between substrates there was variation in both the proportions and quantities of acids produced. Relative substrate fermentability as measured by total acid production at 24 h was: sucrose octa‐acetate > sucrose > stachyose > pregelatinised starch > Raftilose® > verbascose > raffinose > starch acetate > bleached starch > phosphated distarch phosphate > locust bean gum > corn starch > oxidised starch = starch sodium octenyl succinate > di‐starch phosphate > acetylated di‐starch adipate = gum arabic > acid‐treated starch > gum tragacanth > gum guar > acetylated di‐starch phosphate = hydroxypropyl di‐starch phosphate > hydroxypropyl starch > pectin > raffinose undeca‐acetate > stachyose acetate > gum karaya = cellulose propionate > cellulose acetate > cellulose > cellulose butyrate > hydroxypropyl methyl cellulose > carrageenan > methyl cellulose. Chemically modified starches were similar to corn starch in the amounts of total SCFAs produced at 24 h. Synthetic sugar esters could have potential application as vehicles to deliver supraphysiological amounts of SCFAs during in vivo studies of colonic fermentation. © 2000 Society of Chemical Industry  相似文献   

12.
Starch modified by combination with sodium carboxymethylcellulose (CMC) has been reported to have improved film properties. In this study, rice starches with different amylose content were heat-treated in a dry state after being impregnated with low or medium-viscosity CMC. Noticeable change was found in pasting properties of the starches after dry heat treatment with CMC. It indicated that crosslinkage occurred between the starch and CMC. The waxy starch showed significant change in viscosity throughout pasting after dry heating with CMC, suggesting that the ester bonds were mostly formed between the hydroxyl groups in amylopectin branches of rice starch and carboxylate acid groups of CMC. Particle size also increased after heat treatment with CMC. The modified starch-based films showed improvement in the tensile strength. Both water vapor and oxygen permeability reduced for the modified starch-based films. Dynamic mechanical analysis (DMA) study showed that the values of G′ of modified starch-based film were higher than those of native starch-based film over the temperature range −40 to 60 °C. The heating process with CMC could be used as a modification method for starch and provide desirable properties of starch-based films.  相似文献   

13.
Phaseolus lunatus starch was modified by esterification with octenyl succinic anhydride (OSA) and reaction effect evaluated in terms of chemical composition, gelatinization, pasting and emulsification properties. Succinylation was done using a 23 factorial design with four replicates of the central treatment. Evaluated factors and levels were OSA concentration (1% and 3%), pH (7 and 9) and reaction time (30 and 60 min). Succinyl group percentage was the response variable. The optimum treatment was a reaction with 3% OSA at pH 7 for 30 min, which produced 0.5083% succinyl groups and 0.0083° of substitution. No significant changes were observed in proximate composition between the native and derivative starches. Apparent amylose level decreased notably from 32.4% to 23.6% due to OSA inclusion. Succinylation decreased starch gelatinization temperature (75.3–64.6 °C), decreased enthalpy (10.7–9.7 J/g), increased viscosity (700–1000 BU), increased emulsifying capacity (0.47–0.53 ml oil/ml sample), and made emulsions more stable over time. Starch modification did not, however, improve stability in heating–cooling processes.  相似文献   

14.
The high cost and potential toxicity of biodegradable polymers like poly(lactic‐co‐glycolic)acid (PLGA) has increased the interest in natural and modified biopolymers as bioactive carriers. This study characterized the physical stability (water sorption and state transition behavior) of selected starch and proteins: octenyl succinate–modified depolymerized waxy corn starch (DWxCn), waxy rice starch (DWxRc), phytoglycogen, whey protein concentrate (80%, WPC), whey protein isolate (WPI), and α‐lactalbumin (α‐L) to determine their potential as carriers of bioactive compounds under different environmental conditions. After enzyme modification and particle size characterization, glass transition temperature and moisture isotherms were used to characterize the systems. DWxCn and DWxRc had increased water sorption compared to native starch. The level of octenyl succinate anhydrate (OSA) modification (3% and 7%) did not reduce the water sorption of the DWxCn and phytoglycogen samples. The Guggenheim–Andersen–de Boer model indicated that native waxy corn had significantly (P < 0.05) higher water monolayer capacity followed by 3%‐OSA‐modified DWxCn, WPI, 3%‐OSA‐modified DWxRc, α‐L, and native phytoglycogen. WPC had significantly lower water monolayer capacity. All Tg values matched with the solid‐like appearance of the biopolymers. Native polysaccharides and whey proteins had higher glass transition temperature (Tg) values. On the other hand, depolymerized waxy starches at 7%‐OSA modification had a “melted” appearance when exposed to environments with high relative humidity (above 70%) after 10 days at 23 °C. The use of depolymerized and OSA‐modified polysaccharides blended with proteins created more stable blends of biopolymers. Hence, this biopolymer would be suitable for materials exposed to high humidity environments in food applications.  相似文献   

15.
通过添加不同改性淀粉制备冷冻酸乳冰淇淋,分别研究不同改性淀粉及添加量在冷冻处理前对酸乳样品的硬度和黏度的影响,以及在冷冻处理后对冷冻酸乳冰淇淋样品冻融稳定性和感官品质的影响。结果显示,随着改性淀粉添加量在0~1.2 g/100 g范围增加,酸乳样品的硬度和黏度均呈现不同程度的增加,并且全部冷冻酸乳冰淇淋样品的乳析指数均呈现不同程度的下降,其中添加辛烯基琥珀酸酐(OSA)酯化淀粉微粒的样品,其硬度和黏度的增幅最大,分别为67.64%和93.43%,并且表现出最佳的冻融稳定性,其乳析指数下降幅度最大,为52.28%。当OSA酯化淀粉微粒添加量为0.8 g/100 g时,其感官品评综合得分最高,为90.54分,表明此种改性淀粉在提高冷冻酸乳冰淇淋品质上具有良好的应用效果。  相似文献   

16.
Waxy corn starch (amylopectin) and three of its chemical derivatives: acetylated cross‐linked (ACLS), oxidized (OS), and octenyl‐succinylated (OSA), were used together with additives such as Tween 80, sorbitol, and beeswax suspension or safflower oil to test their effect on film‐forming solutions (FFS) and films. The objectives of this study were the starch structure characterization, and its correlation with rheological properties of FFS and solubility, opacity, and water vapor permeability (WVP) of the produced films. Analysis of starch structure, rheological characterization, and films micrographs revealed that the starches contained predominantly low MW amylopectin molecules and film properties depended on their ability to reorganize. Additionally, the interaction among groups introduced in modified starches or with additive molecules can hinder or promote starch reorganization, resulting in films with increased or reduced WVP, solubility and transparency properties. Films were obtained by casting and showed a thickness less than 41 µm. Films prepared with OS and beeswax exhibited the best reorganizing capacity of FFS, resulting in less soluble (30.0 ± 1.6%), highly transparent (23.2 ± 3.3 UA × nm) and less permeable films (0.485 ± 0.016 g · mm · m−2 · h−1 · kPa−1). On the other hand, ACLS showed an opposite trend which was attributed to a more open film structure. These results contribute to understand the molecular interactions of waxy starch molecules in FFS which may be useful to design tailored coatings.  相似文献   

17.
保鲜方便米粉抗老化研究   总被引:2,自引:3,他引:2  
测定了多种添加剂对保鲜方便米粉的抗老化效果。试验结果表明:植物油、魔芋精粉、土豆淀粉、单甘酯、蔗糖脂、黄原胶、瓜尔豆胶、谷朊粉、马铃薯变性淀粉、木薯变性淀粉、羧甲基纤维素钠(CMC)、等都有一定的抗老化作用,但自制酶制剂效果最好。  相似文献   

18.
The aim of this study was to analyze the influence of chemically modified starches (HDP and ADA) and high amylose corn starch (HACS) on the rheological and thermal properties of gluten-free dough based on corn and potato starches with pectin and guar gum. The results indicate that the dough with the addition of modified starch behaves as weak gel, the value of storage modulus G′ significantly depends on the frequency and the values of tan δ = G″/G′ range from 0.32 to 0.49. Significant influence of hydroxypropylated distarch phosphate (HDP) on the viscoelastic properties of dough was observed. The share of modified starch in the system caused a decrease of the instantaneous and viscoelastic compliance. It also influenced the retardation time and zero shear viscosity. The application of modified starches (HDP and ADA) for dough preparation did not have much impact on the pasting characteristics. However, significant reduction of the onset and end viscosities were found for high amylose starch (HACS). Thermograms obtained for individual dough systems were characterized by the presence of two peaks, associated with the existence of two different starches in the system. No significant effect of modified starch on the onset temperature (TO) and only a slight effect of HACS starch on gelatinization enthalpy were observed. However, the level of addition of individual starch affected peak and end (TE) temperatures, depending on the type of preparation.  相似文献   

19.
为改善市售小麦粉(蛋白质11%)制作汤饭面片的面团特性和品质,在小麦粉中添加不同磷酸盐、食用胶类和淀粉,测定复配粉的糊化特性、面团特性以及面片复水后的品质比较。结果表明,磷酸盐能增加面粉峰值粘度、最低粘度、最终粘度、衰减值和回生值,对峰值时间、糊化温度影响不显著(p>0.05)。焦磷酸钠和三聚磷酸盐显著增加了面粉峰值粘度(p<0.05);聚丙烯酸钠显著降低了面粉回生值和衰减值(p<0.05),分别为767 cP、593 cP;马铃薯变性淀粉、木薯变性淀粉显著降低了面粉的回生值(p<0.05)。磷酸盐、食用胶对面团粉质特性有显著提高,淀粉降低了面团的粉质特性。六偏磷酸钠、三聚磷酸盐和焦磷酸钠弱化度最低,都为4 BU;聚丙烯酸钠、黄原胶弱化度最小分别为1 BU、4 BU。3种改良剂均能改善面片的剪切特性,除碳酸氢钠其他试验组能有效改善面片复水性和感官。三聚磷酸盐、黄原胶和马铃薯变性淀粉在试验组中对面片的硬度和延展性更好,复水性、品质和适口性更佳。综合评价:添加三聚磷酸盐、黄原胶和马铃薯变性淀粉能够较好的改善面团的特性和面片的品质,并能制作出适合加工新疆汤饭的方便面片。  相似文献   

20.
The retrogradation behavior of waxy maize starch pastes with added xanthan gum was investigated. The pastes were prepared with or without added xanthan gum at two starch concentrations (5:100 and 7:100), at two temperatures within the gelatinization range (70 °C or 72 °C) and at acid or neutral pH. The evolution of the macrostructure (texture, flow behavior and syneresis), microstructure (oscillation rheology) and molecular aggregation (pulsed-field NMR) of the pastes was followed up in an 8 week period during cold storage (7 °C). Heating temperature was found to have a profound effect on the long-term stability of the pastes. Pastes prepared at 70 °C behaved as flocculated dispersions of largely intact, swollen granules which resulted in stable structural properties during the preservation period. At 72 °C, a higher degree of gelatinization and degradation was observed, resulting in structurally unstable systems due to association and crystallization of amylopectin. Especially for these systems, xanthan gum was found to enhance the gelation process, probably due to phase separation. Although xanthan gum may restrict the granule disruption during preparation, this beneficial effect on the freshly prepared pastes did not result in an improved stability during storage.  相似文献   

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