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1.
Maranta (Maranta arundinacea L.) can be considered as a non-conventional raw material for starch. The objective of this work was to characterize the maranta starch. These starch granules had spherical and elongated geometries with average size of 56.60 μm. The maranta starch presented B-type crystal, revealed by x-ray spectra, and gelatinization temperature of 65.5°C as determined by thermal (differential scanning calorimetry) analysis. Maranta starch suspensions have a pseudoplastic behavior which was well described using a power law model. Storage and loss moduli increased drastically during gelatinization process, corroborating with differential scanning calorimetry results. In general, maranta starch could have numerous applications in the food industry.  相似文献   

2.
竹芋淀粉的性质研究   总被引:4,自引:0,他引:4  
研究测定竹芋淀粉颗粒、糊及其凝胶等特性。发现竹芋淀粉颗粒多呈卵形和椭圆形,直径约8~30μm,平均直径为22μm,大颗粒表面有明显的轮纹。竹芋淀粉颗粒的轮纹及偏光十字明亮清晰、淀粉颗粒表面呈明显的偏光十字,形状不规则、有相当部分呈垂直十字、若干呈斜十字和X形。X-衍射呈A型结晶图样,结晶度为36.1%,糊化温度为58.2℃。  相似文献   

3.
In Far East faba bean starch is always present in several food applications. But often the starch quality is low and knowledge of characteristic attributes do not exist. Therefore, we tried to isolate a faba bean starch with few impurities, and to analyse the starch quality with different types of techniques. Furthermore, a comparison between three cultivars (two Chinese and one German) should point to possible differences. The crude protein content of all isolated starches was lower than 0.3% dry matter. Particle size distribution of the starch granules was mainly between 20 and 40 μm diameter. Gelatinization range was between 56 and 81°C. Brabender viscograms showed very stable hot gels with no viscosity reduction during the hot phase. A gel filtration analysis of the starch molecules gave relevance to molecular weights of amylose between 100 and 200 × 103 MW. In spite of quite different genetic backgrounds and agricultural conditions the quality of the starches was not very different between the two Chinese and one German cultivars.  相似文献   

4.
Black gram (Phaseolus mungo L.) starch was modified by heat and moisture treatments, acetylation, oxidation, cross-linking, and adding free fatty acids (palmitic, stearic, and linoleic). Heat and low moisture treatment, acetylation, oxidation, and cross-linking lowered the starch gelatinization temperature by 1–6°C, while adding fatty acids and the high moisture-heat treatment raised it by 1–4°C. All modifications caused an increase in least gelation concentration of starch. High moisture-heat treatment increased both water and oil absorption of starch. At 95°C, heat-moisture treated, acetylated, and oxidized starches were more soluble, while fatty acid treated and cross-linked starches were less soluble compared to raw starch. The modified starches had greater swelling capacity and solubility at pH 2.0 and 10.0. Heat-moisture treated and chemically modified starches had lower swelling capacity (at 95°C) than that of isolated starch, whereas addition of fatty acids increased it.  相似文献   

5.
以长豇豆籽为原料,采用响应面Box-Behnken分析法优化淀粉提取工艺,并对其形态结构和理化性质进行表征.采用五因素三水平的响应面曲面分析法确定豇豆淀粉提取工艺最佳参数为:NaOH溶液的体积420 mL、浸泡时间17 h、乙醇的体积74 mL、振荡转速167 r/min、振荡时间70 min,此条件下理论提取率为62...  相似文献   

6.
7.
Four varieties of Canadian white bean and their air-classified fractions were analysed for amino acid and proximate composition. The protein enriched fraction (31–35% by wt) prepared by air-classification of finely ground dehulled flour contained 50.3–57.5% protein. Solubility of protein measured as percent of total nitrogen soluble at pH 7.5 was 81.1–83.0%. Water Hydration Capacity and heat thickening property of the protein fraction were similar to other vegetable proteins indicating its potential usefulness as a protein ingredient in processed foods. The amino acid composition was characteristic of leguminous seed proteins with a high lysine content and a low sulfur amino acid content. The lipids and the oligosaccharides were concentrated in the protein enriched fraction. The starch fraction (53% by wt) contained on the average 30% amylose and gave a torque-temperature curve typical of legume starches with slow swelling, no breakdown at constant temperature and shear, and a high set back.  相似文献   

8.
The structure and properties of endosperm starch from high-amylose mutants of rice were examined. The starch in the mutants was characterized by a higher content of amylose and loosely branched amylopectin with longer chains compared with non-mutant starch. The starch granules in the mutants showed high temperatures of gelatinization and a type B pattern in X-ray diffractometry. These properties were similar to those of amylose-extender (ae) starch of maize. The effect of locations where rice plants were grown on the endosperm starches of one high-amylose mutant and a non-mutant was also investigated.  相似文献   

9.
《Food chemistry》2002,76(1):33-43
Characteristics of oil extracted from hempseeds subjected to microwave treatments were evaluated. Microwave treatment improved oil yield, increased carotenoid and other pigment contents and decreased p-anisidine value without significant changes in other properties. Hempseed oil showed absorbance in the UV-B and UV-C ranges with potential for use as a broad spectrum UV protectant. β-Tocopherol concentrations increased, while the major tocopherol, γ-tocopherol, and fatty acid composition of the oil were unaffected by microwave treatment of hempseed. Hempseed oil showed high kinetic stability during heating and cooling, as characterized by differential scanning calorimetry (DSC). Microwave treatment shifted the melting range of oils to lower temperatures and increased oxidation temperatures, suggesting increased protective effect upon heating.  相似文献   

10.
Structures and functional properties of starch from high‐protein, lipoxygenase‐free and low‐linolenic acid soybean variety seeds collected 20 d prior to harvest were investigated. Soybean starches exhibit CB‐type X‐ray diffraction patterns, and granule diameters were very small (0.7 to 4 µm). Soybeans, 20 d prior to harvest contained 10.9–11.7% starch (dry basis). Apparent amylose content was 19–22% and absolute amylose content was 11.8–16.2%. Amylopectin weight‐average molar mass ranged from 5.1 to 11.3×108 g/mol. Amylopectin average branch chain‐length, determined by anion‐exchange chromatography with an amyloglucosidase post‐column and pulsed amperometric detector, was very short relative to other starches (20.4–20.9). Onset gelatinization temperature ranged from 52–54°C, and ΔH was 12–13 J/g. Paste viscosity was low relative to other starches, especially peak (81–93 RVU) and final (93–106 RVU) viscosity. The apparent amylose content of the low‐linolenic acid soybean starch was significantly higher than that of high‐protein soybean starch, and absolute amylose content of low‐linolenic acid soybean starch was significantly higher than that of lipoxygenase‐free soybean starch. Based on our results, investigations on whether soybeans with different fatty acid oil composition have different starch structures would be worthwhile. Field replicates for each soybean variety exhibited high variation in starch characteristics, with further differences in starch structures and functional properties likely to be determined once variation is minimized.  相似文献   

11.
Starch isolated from two accessions of cow cockle (Saponaria vaccaria L.) seeds consisted of uniform size polygonal granules 0.3–1.5 μm in diameter, having 18% amylose content and a melting peak temperature 68°C. The intact granules gave the A-type X-ray diffraction pattern. The debranched starch exhibited the typical bimodal distribution of amylopectin chains (CL 45 and 12) on Biogel P-10. Lipids associated with the cow cockle starch preparations, involving surface and internal lipids, included triglycerides (45%), free fatty acids (FFA, 39%), lysophospholipids (10%) and diglycerides (6%). The major fatty acids found in polar and FFA fraction were palmitic, oleic and linoleic acids. Cow cockle starch exhibited similar viscoamylograph viscosity, solubility and swelling profiles to those of rice starch. Concentrated starch gels also showed the typical viscoelastic behavior of non-waxy cereal starches. In vitro digestibility studies of cow cockle granular starch with B. Subtilis indicated that this starch, compared to rice, is very susceptible to α-amylolysis presumably because of its small granule size.  相似文献   

12.
采用差式扫描量热仪、快速黏度分析仪与物性分析仪研究了大豆分离蛋白、壳聚糖、海藻酸钠、氯化钠和明矾对银杏粉丝品质的影响。结果表明,海藻酸钠和明矾对银杏粉丝品质的影响较大,当海藻酸钠与明矾的添加量分别为质量分数0.50%和0.75%时,银杏粉丝品质较佳。通过对比添加海藻酸钠和明矾的银杏粉丝与市售绿豆粉丝的品质,发现添加海藻酸钠与明矾的银杏粉丝品质相近,接近市售粉丝,表明海藻酸钠可替代明矾添加到银杏粉丝中。  相似文献   

13.
Water yam (Dioscorea alata L.) is suitable for resistant starch high flour because of its high amylose content. The purple, yellow, and white water yams were treated by autoclaving and cooling with one, two, and three cycles to obtain resistant starch. Water yam tubers were cooked in an autoclave for 15 min, and then cooled prior to drying. Autoclaving–cooling of water yams decreased protein, fat, dietary fiber, water soluble polysaccharide, dioscorin, and diosgenin but increased amylose and sugar. The treatments significantly raised resistant starch and reduced in vitro starch digestibility that depended on water yam types, and affected starch granule morphology.  相似文献   

14.
Starch was isolated from four-o'clock flower (Mirabilis jalapa L.) seed by an alkaline process and selected physicochemical properties was determined. The nearly spherical starch granules were approximately 1.5–3.0 μm in diameter. The starch had a pasting temperature of 72.5°C, and an iodine affinity of 3.6%. The Bra-bender viscoamylogram and the swelling pattern indicated the starch underwent restricted swelling. The starch contained only trace amounts of phosphate. Solubility in dimethyl sulfoxide was low, but after being treated with bacterial alpha-amylase, the solubility was high. The degree of syneresis of the pasted starch during storage was high and freeze-thaw stability was low. The properties of this isolated small-granule starch differed from other such starches reported in the literature.  相似文献   

15.
16.
燕麦发芽过程中淀粉理化特性的变化   总被引:2,自引:0,他引:2  
徐建国 《中国粮油学报》2012,27(5):27-30,34
以山西产裸燕麦为原料,在控制的条件下发芽72 h,每间隔12 h取样,测定燕麦淀粉的颗粒结构、溶解度等理化特性。结果表明,燕麦发芽过程中,其淀粉颗粒仍保持了原淀粉的外貌形态和X-射线衍射A型图谱特征。发芽处理使燕麦淀粉的溶解度增加,膨胀度减小,同时会导致淀粉冻融稳定性变差,易于老化。但适度的发芽可增加淀粉的透明度,增强淀粉糊的热稳定性和冷稳定性。  相似文献   

17.
In Mexico, consumption of beans represents 15% of the normal diet of the population in rural zones. Four common bean varieties cultivated in Mexico were studied regarding their chemical composition, starch digestibility and indigestible fraction. The protein level in the samples Huasteco, Tacana and TLP 19 was not different (α = 0.05), but Veracruz cultivar had the highest protein and ash content, and the lowest lipid level. Differences in chemical composition were determined in the cultivars studied. Total starch (TS) ranged between 33.6 and 36.7%, and the cultivars Tacana, TLP 19 and Veracruz were not different in starch content (α = 0.05). The available starch (AS) determined represented between 74 and 87% of TS, due to the resistant starch content and perhaps some complex formed between starch and protein or starch and polyphenols, by the high level of the indigestible fraction determined in the beans. The in vitro α‐amylolysis rate was similar for the different varieties, except for Veracruz cultivar which presented a slightly lower hydrolysis rate.  相似文献   

18.
The in vitro digestibility of native and germinated pigeon pea starches both in raw and cooked forms were investigated. The rate of digestibility (glucoamylase) was different for the two raw starches. There was a preferential utilization of low molecular weight ‘amyloses’ in the germinated samples, during in vitro enzymatic digestion of the raw granule. On acid hydrolyses, germinated samples produced lower molecular weight fragments than did raw starch, though the rate of reducing sugar released was not different. It may therefore be concluded that the size of the „amylopectin”︁ molecule is smaller in germinated starch. The easy availability of low molecular weight „amyloses”︁ may also influence the greater susceptibility of germinated starches to amylolysis even after cooking.  相似文献   

19.
Starch samples from seven major dry pea (Pisum sativum L.) cultivars grown in North Dakota, US was isolated and their physicochemical properties investigated. The objective of the study was to establish the basic foundation of advanced research on physical and chemical modification to improve the functionality of dry pea starches grown in the region. Isolated starch samples were analysed by high performance size exclusion chromatography (HPSEC). Amylose percentages were in the range of 32.2–41.1%. Granules were elliptical or spherical with smooth surfaces based on microscopic analysis. Starch samples had similar gelatinisation transition temperatures and displayed ‘C patterns’. The swelling factors of dry pea starches influenced by temperature were determined at 10° intervals between 50 and 90 °C with continuous mixing. The pasting profiles were studied using a rapid visco analyzer (RVA), which exhibited different pasting profiles. This study indicated that dry pea cultivars grown in the region possess starch with different physicochemical characteristics.  相似文献   

20.
Amylopectin is the principle component of starch. To elucidate the relationships between amylopectin and resistant starch content, six rice mutants with altered fine structure of amylopectin were selected for comparative studies with the primary wild type and two types of amylose‐extender (ae) mutants. Significant differences in resistant starch content were observed among mutants with similarity or differences in amylose levels. Mutants high in resistant starch had significantly increased proportions of short amylopectin chains with DP≤12, decreased levels of intermediate chains with size of 13≤DP≤36, and decreased fractions of long chains with DP≥37. Additionally, there was a mutant different to ae, which was characterized by an increased level of short chains with 8≤DP≤12 and 13≤DP≤24, and a decreased proportion of long chains with DP≥37. The increased contents of short chains with 8≤DP≤12 and decreased of intermediate and long chains with 24≤DP were clearly associated with the increase of resistant starch in rice.  相似文献   

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