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1.
    
The effects of ANN prior to cross‐linking of non‐wx rice starches on a RS level and granular shape were investigated to apply them for a fat replacer with RS in a liquid food system. Acid hydrolysis and sonication were also evaluated to improve RS quality. The RS level was also compared with AOAC and P/G methods. The RS levels of CRS analyzed with the AOAC method were higher than those analyzed with the P/G method, but the differences in the RS level of CRS affected an ANN condition and starch content during cross‐linking. When ANN was conducted at 50°C for 12 h using the AOAC method, and starch content (40%) used in cross‐linking was at 45°C for 3 h, the highest RS level of CRS treated with ANN was 69.4% compared to 38.3% RS level of CRS without ANN. The 1 h acid hydrolysis (pH 4.0) of CRS treated ANN increased 114.5% of the RS level (79.4% compared to 69.4% in CRS treated ANN), regardless of which analytical methods were used. CRS granules remained the same as native ones with a polygonal shape and A type crystallinity even after being treated with ANN, and acid hydrolysis. The sonication before cross‐linking reaction increased the RS level and prevented increase in size from aggregating CRS granules.  相似文献   

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Banana starch was cross‐linked using different cross‐linking reagents, phosphoryl chloride (POCl3), sodium trimetaphosphate (STMP), and epichlorohydrin (ECH), under alkaline conditions. The reaction conditions were selected to produce similar pasting profiles. The effects of the different cross‐linking reagents on the physicochemical and structural characteristics of cross‐linked starches were evaluated. The microscopy study did not show difference on the surface of the granules. Slight decrease in the peak temperature and enthalpy were found in the cross‐linked banana starch. The chemical groups introduced in the starch molecules by the diverse reagents promoted the re‐association of starch chains during storage. The rheological analysis of all starch dispersion at 10% (flow curves) showed a non‐Newtonian shear‐thinning; pastes obtained were time‐independent, suggesting an important contribution of the continuous phase. Structural study showed that the cross‐linked STMP‐starch had the lowest level of amylose and the ratio short/long amylopectin chains. The three reagents used for cross‐linking presented different action mode on starch granule and its components.  相似文献   

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为考察重量法与国际公认的美国分析化学家协会(Association of Official Analytical Chemists,AOAC)方法在测定抗性淀粉含量时能否互换,选择日常生活中常见的8种含淀粉零食和课题组研发生产的玉米回生淀粉Ⅰ、玉米回生淀粉Ⅱ、含醇溶蛋白玉米回生淀粉、分别添加了40%和80%含醇溶蛋白玉...  相似文献   

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The gel formation properties of non‐waxy rice starch with cross‐linked resistant starch with phosphate (RS4, 10, 20, and 30% based on rice starch) prepared from three rice varieties with different amylose (AM) content were investigated to increase dietary fiber content, improve gel structure, and reduce the glycemic index of rice products. The AM contents of rice starches were 1.71% in Hanganchal1, 22.47% in Nampyeong, and 33.39% in Goamy. All RS4 showed A‐type crystallinity and their RS levels were 46.91, 54.54, and 66.01%, respectively. The initial pasting temperatures of RS4 added rice starches increased as RS4 contents increased, but peak and breakdown viscosities and enthalpy change (△H) reduced. The RS4 addition improved gel shape and texture properties including hardness, cohesiveness, and gumminess, except the 30% Goamy RS4 added gel. The 20% RS4 addition was appropriate to form rice starch gels. The network structure of RS4 added gel formed more regular and firmer than that of control, because RS4 granules were entrapped within the gel matrix like observed by light microscope and scanning electron microscopy. It is suggested that RS4 not only assist in forming a rigid network structure but also increasing a dietary fiber content.
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7.
利用偏光显微、X射线衍射等现代分析技术,研究了酯化改性后淀粉颗粒形貌和结晶结构的变化。结果表明,与HylonV玉米淀粉相比,酯化改性后得到的RS4型抗消化淀粉的颗粒形貌和结晶结构都受到不同程度的破坏,尤其导致了结晶形态由B型向V型转变。由此引起淀粉的消化性能发生改变,经体外模拟试验表明,RS4型抗消化淀粉在人工胃液和人工小肠液中都有良好的抗消化性能,且随着抗消化淀粉含量的增加,抗消化性能越显著,显示了其良好的结肠靶向性。  相似文献   

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Corn starch (20%, w/w) was non‐thermally and conventionally cross‐linked with phosphorus oxychloride (POCl3; 0.01, 0.05, or 0.1%, based on dry weight of starch) at 400 MPa for 5, 15 and 30 min and at 45°C for 2 h, respectively. Swelling power and solubility of both non‐thermally and conventionally cross‐linked corn starches were relatively lower than those of native corn starch. The pressure holding time did not affect the solubility and swelling power of non‐thermally cross‐linked corn starches. X‐ray diffraction patterns and relative crystallinity were not significantly altered by both conventional and non‐thermal cross‐linking. DSC thermal characteristics of both non‐thermally and conventionally cross‐linked corn starches were not significantly changed indicating that the double helical structure of amylopectin was not influenced by both conventional and non‐thermal cross‐linking reactions. Both non‐thermal and conventional cross‐linking greatly affected the Rapid Visco Analyser (RVA) pasting properties, such as increase in pasting temperature and decrease in peak viscosity compared to native starch. This result suggests that in case of cross‐linking using POCl3, both non‐thermal and conventional methods result in similar physicochemical properties and non‐thermal cross‐linking with POCl3 can reduce the reaction time from 2 h to 15 min. This work shows the potential and possibility of non‐thermal starch modification and provides the basic and scientific information on the physicochemical properties of non‐thermally cross‐linked corn starches with phosphorus oxychloride using UHP.  相似文献   

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Corn starch was chemically modified using sodium chloroacetate to yield carboxymethyl starch (CMS). The aqueous solutions of CMS at 15 and 50% (w/w) concentration were then irradiated by electron beam (EB) at various dosages (1, 2, 3, 5, 10, 20, and 50 kGy), resulting in a cross‐linked carboxymethyl starch (CCMS). The maximum gel fraction, i.e. the highest degree of cross‐linking, was achieved with a 50% (w/w) aqueous CMS solution irradiated at 2 kGy EB dosage. Metal removal efficiency of the CCMS was then evaluated for the extraction of copper (Cu) and cadmium (Cd) ions from aqueous solutions. Our results showed that the metal adsorption is pH dependent and the adsorption increases with increase of the pH of the metal solution from acidic towards neutral. The adsorption efficiency also showed the maximum value at the highest gel content, demonstrating the enhancement of adsorption by the physical entrapment of the ions in the CCMS network in addition to the primary chemical adsorption.  相似文献   

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采用In-Vitro模型及结合扫描电子显微技术,在模拟人体结肠环境中,考察了RS4型抗消化淀粉薄膜的结肠微生物降解性能。结果表明,RS4型抗消化淀粉能够被结肠中的微生物特异性降解,具有良好的结肠靶向降解性,可以控制生物活性物质的释放。同时,以牛血清白蛋白为模型生物活性物质,建立了以RS4型抗消化淀粉为载体的BSA口服结肠靶向控释系统,经体外释放特性研究,该系统能保护生物大分子牛血清白蛋白(BSA)穿过模拟人体上消化道,并在人工模拟结肠环境中具有良好的释放特性。  相似文献   

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In this work modified starches such as porous starch (PS) and cross‐linked phosphorylated porous starch (PPS) were used as tobacco filter to investigate their adsorption efficiency on the tar, ammonia (NH3), hydrocyanic acid (HCN), crotonaldehyde, and total particulate matter (TPM) in mainstream cigarette smoke. The pore properties and structural stability of the modified starches have been evaluated and the adsorption relationship between the modified starches and the main toxicants in tobacco smoke has also been established. Analytes of mainstream smoke from experimental cigarettes show reductions in yields of some measured constituents in mainstream cigarette smoke, such as tar, HCN, NH3, crotonaldehyde, and TPM. The largest reductions are for NH3 levels, up to 35.93% in one case, observed from the tobacco filter containing PPS. The largest reductions in mainstream yields of HCN (13.04%) and crotonaldehyde (31.06%) smoke toxicants were also observed. These results indicate that reducing exposure to some smoke toxicants is possible using the modified starches such as PS and PPS as tobacco filter.  相似文献   

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研究较快速、准确测定粳米淀粉消化特性的方法。以粳米淀粉为试验对象,AOAC法(AOAC Official Method 2002.02)测定结果为基准,对Englyst法的酶解反应时间、混合酶比例、混合酶的添加量、混合酶pH等试验条件进行优化,得到适合粳米淀粉消化特性测定的方法,并对该方法测定结果进行准确度、精密度分析。结果表明,当酶解时间为270 min、混合酶比例[α-胰腺淀粉酶(AMY):淀粉葡萄糖苷酶(AMG)]为10:1、混合酶添加量为AMY(3600 U)+AMG(360 U)、混合酶pH为6.0、样品不经糊化处理时,测得的粳米淀粉中RS含量2.13%±0.05%与AOAC法测定结果2.02%±0.06%无显著差异,并且其测定时间由AOAC法的16 h调整为270 min,大大缩短了试验时间;与原Englyst方法相比,改进后的Englyst法测得的结果2.13%±0.05%准确度和精密度高,重现性好。因此,改进后的Englyst法可以快速、准确地测定粳米淀粉的消化特性。  相似文献   

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目的 采用响应面法优化农产品中抗性淀粉(Resistant Starch, RS)的体外检测方法。方法 选择谷类、薯类、豆类3类抗性淀粉主要来源的农产品,设计单因素试验和Box-Behnken试验。单因素试验考察了水浴时间、淀粉葡萄糖苷酶(AMYLOGLUCOSIDASE, AMG)作用温度、AMG作用时间、AMG添加量和离心力与离心时间5个条件,并选择AMG作用温度、AMG作用时间、AMG添加量来设计Box-Behnken试验。结果 根据单因素试验,确定了水浴时间为14 h,离心条件选择4500 g离心5 min;根据响应面实验确定对RS含量检测结果影响程度排序为AMG添加量>AMG作用时间>AMG作用温度。结合单因素响应面试验,确定最佳检测方法为水浴14 h,4500 g离心5 min,AMG作用温度49℃、AMG添加量0.2 mL、AMG作用时间38 min。结论 优化后的方法重复性良好,适用于玉米、马铃薯和红豆3类样品,且有望适用于其他主要农产品。  相似文献   

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Normal corn starch (NCS) was treated by both autoclaving‐cooling and cross‐linking to produce resistant starch (RS). The RS yield, crystalline structure, as well as other physicochemical properties of the modified starch were investigated. The yield of RS was 12.2% by four autoclaving‐cooling cycles, and it could be further increased up to 31.0% by the subsequent cross‐linking using sodium trimetaphosphate/sodium tripolyphosphate. The scanning electron microscopy images clearly illustrated that the granular structure of native starch was disrupted and a continuous network with irregular shape was formed after autoclaving‐cooling cycles. The subsequent chemical cross‐linking appeared to make the network structure more compact and dense. X‐ray diffraction patterns showed that B‐ and V‐types coexisted in all the modified corn starches, and all these modified starches exhibited very low viscosity which remained almost constant regardless of temperature changes.  相似文献   

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Individuals were given ERSR (enzyme-resistant starch rusks) to consume for breakfast, and its effect on blood glucose was examined. Fifty-four people participated in this study as two groups ((WWR (whole wheat rusks): 27 and ERSR: 27)). Each rusk contains 30 g of digestible CHO. After the consumption started, measurements were made at 30-min intervals until 120 min. In total AUC (area under the curve) values between WWR and ERSR, ERSR was significantly higher (P < 0.001). In normal-weight individuals, the total AUC value of ERSR consumption was significantly higher than WWR (P < 0.001), and in obese individuals, no significant difference was observed. Blood glucose fluctuations were higher in ERSR compared to WWR. It was also observed that this difference was observed in normal-weight individuals, while no such difference was observed in individuals with obesity. Although ERSR consumption seems advisable for obese individuals, it should be supported by longer studies.  相似文献   

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《Starch - St?rke》2018,70(5-6)
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This study aims to compare the effect of enzyme-resistant starch flour (ERSF) and standard wheat flour (SWF) bagels given as a mid-afternoon snack on blood glucose (BG) levels in patients with insulin-treated type 2 diabetes mellitus (T2DM). First, bagels containing 15 g of carbohydrates are prepared using ERSF or SWF. Then, the effect of bagels prepared using SWF or ERSF on BG levels is examined through clinical research. A continuous glucose monitoring system (CGMS) device is placed and then, the patients are given three packages of bagels that are visually similar and are asked to consume the red package (SWF bagel) on the first day and blue packages (ERSF bagels) on the second and third days as a mid-afternoon snack, without consuming anything else. The increase in BG from ERSF is less than that caused by SWF bagel consumption, and SWF is found to have higher BG averages than ERSF (ERSF: 150 mg dL−1, SWF: 170 mg dL−1). Patients stated that they like the taste and do not feel any discomfort while consuming ERSF bagels. ERSF bagels have higher fiber content and cause more even fluctuations in BG levels than SWF bagels. Food fortification using ERSF foods can be recommended for patients with T2DM.  相似文献   

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A resistant starch (RS)‐rich powder was prepared from phosphate cross‐linked banana starch. Serial autoclaving and cooling treatments of this cross‐linked material were also made. The powders were evaluated for chemical composition, resistant starch content, thermal characteristics, as well as for swelling and solubility properties. The parental cross‐linked starch had similar lipid and protein contents than its autoclaved counterpart, but the ash content decreased after autoclaving, a pattern that is in agreement with the low phosphorus index and degree of substitution recorded in the autoclaved preparation. Although the RS content in the autoclaved cross‐linked product was lower than in the non‐autoclaved starch, the autoclaved product still exhibited a remarkable indigestibility. The peak temperatures of gelatinization were 86.6 and 68.5ºC for cross‐linked and autoclaved cross‐linked starch, respectively. At low temperatures the autoclaved modified starch exhibited greater swelling values than its cross‐linked counterpart. The pattern of solubility values resembled the swelling behavior of both samples. The autoclaved cross‐linked banana starch appears suitable for the formulation of foods requiring none or moderate further heat treatment.  相似文献   

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