Inheritance Analysis and QTL Mapping of Rice Starch Viscosity (Rapid Visco Analyzer Profile) Characteristics

The rice starch viscosity characteristics, which can be indicated by Rapid Visco Analyzer profile （RVA profile）, have been proved useful for the evaluation of cooking and eating quality in rice breeding program. To study the inheritance of the RVA profile, an F2 population of Wuyujing 3/Aichi 106 was used. The results indicated that the peak viscosity （PKV） was a typical quantitative character, and the hot paste viscosity （HPV）, cool paste viscosity （CPV）, setback viscosity （SBV）, breakdown viscosity （BDV）, and consistence viscosity （CSV） might be controlled by one major gene and several minor genes To elucidate the genetic basis of the paste viscosity characteristics, a recombinant inbred line （RIL） population derived from Nikken 2/Milyang 23 and its genetic linkage map were used to map the QTLs controlling RVA profiles in 2005 and 2006. A total of 34 QTLs distributed on chromosomes 1,2, 3, 4, 6, 7 and 8 were detected, including 19 and 15 QTLs in 2005 and 2006 respectively. Eight QTLs were both detected in the two years, qHPV6, qCPV6, qCSV6, qSBV6, and qBDV6 were located on chromosome 6, while qHPV2, qCSV2, and qCPV2were on chromosome 2.

Starch RVA Profile Properties for Cold Tolerant and Sensitive Cultivars of Japonica Rice at Different Altitudes

[Objective] By investigating of change rule rice starch RVA profile properties and the influence of cold tolerance on rice quality,the aim was to provide scientific references to the breeding of new cold-tolerant japonica rice varieties with high quality in the Yunnan plateau.[Method] Four cold-tolerant and five cold-sensitive japonica rice cultivars were grown at three locations with different altitudes in Yunnan plateau to investigate rice starch RVA profile characteristics.[Result] The results showed that with increasing altitude,the setback viscosity in cold-sensitive cultivars increased significantly,while the peak viscosity and breakdown viscosity decreased significantly.However,the peak viscosity and breakdown viscosity in cold-tolerant cultivars initially decreased and then gradually increased with rising altitude,whereas the setback viscosity initially increased and then decreased.[Conclusion] The starch RVA parameters of cold-tolerant cultivars were less sensitive to different environments than those of cold-sensitive cultivars.Cooking and eating quality of cold-tolerant cultivars had relatively stable trends with rising altitude,whereas cooking and eating quality of cold-sensitive cultivars had a trend toward inferior.

Effects of Different Sowing Dates and Sites on Starch RVA Profile Characteristics of Different Ecotypes of Rice (Oryza sativa, L. japonica)

[Objective] This study aimed to investigate the effects of different sowing dates and sites on starch RVA profile characteristics of different ecotypes of japonica rice. [Method] Five different ecotypes of japonica rice were sown at seven different dates in four rice planting regions in Jiangsu Province to analyze the differences in starch RVA profile parameters among different rice varieties. [Result] Among eight parameters of rice starch RVA profile, peak time exhibited no significant differences among different sites, while other seven parameters varied significantly or extremely significantly among different sites, sowing dates and varieties. Specifically, rice variety exerted the most significant effects on rice starch RVA profile parameters. Starch RVA profile characteristics varied significantly among different ecological conditions but exhibited no significant differences among different latitudes. To be specific, in different sites, peak viscosity （PKV）, hot paste viscosity （HPV） and breakdown viscosity （BDV） demonstrated a descending order of Huai＇an 〉 Suzhou 〉 Lianyungang 〉 Yangzhou. Cool paste viscosity （CPV） and consistence viscosity （CSV） were higher in the north than in the south; specifically, CPV and CSV were significantly higher in Lianyungang and Huai＇an than in Yangzhou and Suzhou. Setback viscosity （SBV） showed an increasing trend with increasing latitude; specifically, SBV was significantly lower in Suzhou than in other three sites. Pasting temperature （PAT） and peak time （PET） changed slightly among different latitudes. With the postponing of sowing date, peak viscosity （PKV）, hot paste viscosity （HPV）, cool paste viscosity （CPV） and peak time （PET） showed a decreasing trend, setback viscosity （SBV） and consistence viscosity （CSV） increased, breakdown viscosity （BDV） increased first and then decreased, whereas pasting temperature （PAT） decreased first and then increased. Furthermore, rice starch RVA profile parameters showed the same variation trend with sowing date in different sites; early sowing within suitable sowing dates could effectively improve the parameters of rice starch RVA profile. However, different parameters exerted different variations among different sites and most parameters were higher in the north than in the south, which indicated that starch RVA profile parameters were significantly affected by sowing date in the north of Jiangsu Province. Among eight starch RVA profile parameters, setback viscosity exhibited the maximum variation coefficient, while peak time exhibited the minimum variation coefficient. Among five rice varieties, Nanjing 46 exhibited the highest peak viscosity and breakdown viscosity and the lowest setback viscosity and consistence viscosity, suggesting that Nanjing 46 had the most appropriate starch RVA profile characteristics and the best cooking and eating quality. Lianjing 4 exhibited relatively high peak viscosity and breakdown viscosity, and relatively low setback viscosity and consistence viscosity, suggesting that Lianjing 4 had good starch RVA profile characteristics. Different sowing dates and sites exerted significant effects on starch RVA profiles of different eco- types of japonica rice. Rice starch RVA profile characteristics varied significantly among different sites but exhibited no significant variations among different latitudes. In addition, starch RVA profile characteristics varied significantly among different sowing dates. Therefore, early sowing of the same variety was conducive to improving starch RVA profile characteristics in appropriate planting regions. [Conclusion] This study provided a theoretical basis for producing high-quality rice and improving the eating quality of rice in Jiangsu Province.

Different dietary starch sources alter the carcass traits, meat quality, and the profile of muscle amino acid and fatty acid in finishing pigs

Background: With increasing health awareness among consumers, the demand for healthier, tastier, higher quality and nutritional value pork is increasing. It has been shown that different dietary starch sources can alter the carcass traits and meat quality. However, research on the effects of different starch sources with clear different amylose/amylopectin ratio on the amino acid and fatty acid composition in Longissimus thoracis(L. thoracis) muscle of pigs is limited. This study aimed to investigate the effects of different dietary starch sources on carcass traits, meat quality, muscle amino acid and fatty acid composition, and the mRNA expression levels of genes involved in lipid metabolism and muscle fiber characteristics in finishing pigs. A total of 72 Duroc × Landrace × Large White barrows were randomly allocated to 3 different dietary treatment groups with 8 replicate pens/group and 3 pigs per pen.Tapioca starch(TS), corn starch(CS), and pea starch(PS), with amylose/amylopectin ratio of 0.11, 0.25, and 0.44,respectively, were used as their dietary starch sources for 40 days.Results: Results showed that the PS diet significantly increased(P < 0.05) the final body weight, average daily gain,loin-eye area, and fat-free lean index compared with the TS diet, but significantly decreased(P < 0.05) the feed to gain ratio and backfat thickness. Compared with the TS diet, PS diet also increased(P < 0.05) the pH45 min, marbling scores, the content of intramuscular fat and inosine monophosphate in the L. thoracis, and decreased(P < 0.05) the drip loss and shear force. In addition, compared with the TS diet, PS diet increased(P < 0.05) the proportions of flavor amino acids, DHA, EPA, and n-3 polyunsaturated fatty acid(PUFA) in the L. thoracis compared with TS diet,but decreased(P < 0.05) the ratio of n-6/n-3 PUFA. Furthermore, compared with the TS diet, PS diet also upregulated(P < 0.05) the lipogenic genes(FAS, LPL, SCD, ACCα) and myosin heavy-chain(MyHC)-IIa mRNA expression levels compared with the TS diet, but downregulated(P < 0.05) the CPT1 B and MyHC-IIb mRNA levels.Conclusions: In conclusion, these results provided compelling evidence that the different dietary starch source altered the carcass traits, meat flavor and quality in finishing pigs, and consumption of a diet with higher amylose/amylopectin ratio results in the production of a healthy, higher quality, and nutritional value pork.

Viscosity profile prediction of a heavy crude oil during lifting in two deep artesian wells

It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.

Effects of Different Ecological Conditions on Grain Quality and RVA Profile Characteristics of Japonica Rice Varieties from Yunnan Plateau of China and Korea

[Objective] This study aimed to investigate the variation characteristics of Yunnan and Korean japonica rice quality under different environmental conditions in Yunnan Plateau. [Method] Ten Yunnan japonica rice varieties and six Korean japonica rice varieties were selected to investigate the effects of ecological conditions on grain quality characteristics and starch RVA profile characteristic values of Yunnan and Korean japonica rice. [Result] The coefficient of variation of Yunnan and Korean japonica rice reached the maximum in setback viscosity (SBV). The coefficients of variation of brown rice length (BRL), chalkiness rate (CR), amylose content (AC), protein content (PC), alkali digestion value (ADV), final viscosity (FLV), setback viscosity (SBV) and peak time (PeT) of Yunnan japonica rice varieties were significantly higher than those of Korean japonica rice, while other grain quality characteristics were contrary. With the increasing altitudes, BRL, brown rice width (BRW), length-width ratio (L/W), whiteness (WH), AC, ADV, FLV and consistence viscosity (CTV) of Yunnan japonica rice and BRL, BRW, WH, PC, peak viscosity (PKV), hot viscosity (HTV) and breakdown viscosity (BDV) of Korean japonica rice were significantly reduced , while CR, PC, HTV and PeT of Yunnan japonica rice and L/W, AC, ADV and CTV of Korean japonica rice significantly increased, but CR of Korean japonica rice showed no significantly variation. PKV, BDV and pasting temperature (PaT) of Yunnan japonica rice and PaT of Korean japonica rice showed an upward trend after an initial drop with the increasing altitudes, while SBV of Yunnan japonica rice and FLV and PeT of Korean japonica rice were contrary. [Conclusion] This study provided theoretical basis for breeding of japonica rice in Yunnan Plateau.

Effects of Different Sowing Dates and Sites on Grain Quality and RVA Profile of Nanjing 46,a Popular Cultivar of Japonica Rice(Oryza sativa L.)

[Objective] This study was performed to determine the effects of sowing dates and sites on grain quality and Rapid Viscosity Analyzer （RVA） profile of Nan-jing 46. [Method] The field experiments were carried out at five sites in Jiangsu Province, and in every site, the seeds were sowing on seven different dates. RVA related indices were measured after harvest. [Result] Along with the delay of sowing date, the mil ing quality of Nanjing 46 increased at first and then reduced, while its appearance quality went up and the cooling and edible quality decreased. With the sowing sites moving southward, the rice mil ing quality, appearance quality, and cooling and edible quality of Nanjing 46 decreased at first and then increased. Grain traits responded variably to the sowing dates and sites. The brown rice rate, grain width, grain length, length/width, mil ed rice rate and head mil ed rice rate were less affected, while the chalky rice rate and chalkiness degree were more af-fected. The gelatinization temperature, protein content, amylose content, gel consis-tency and eating value were in-between. The RVA profile analysis revealed that the breakdown value, setback value and pasting temperature were affected by the sow-ing date and geographical environment. The peak viscosity, hot viscosity, cool vis-cosity and peak time were influenced more by geographical environment. With the delay of the sowing date, peak viscosity, hot viscosity, cool viscosity, setback value and pasting temperature decreased at first and then increased, while the breakdown value changed inversely, and the peak time did not exhibit a regular trend. With the decrease of latitude, the peak viscosity, hot viscosity, breakdown and cool viscosity declined at first and then increased, the setback value and peak time decreased, while the pasting temperature increased. [Conclusion] This study wil provide refer-ences for the effective production of Nanjing 46.

RVA and Farinograph Properties Study on Blends of Resistant Starch and Wheat Flour

Resistant starch （RS） is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco analysis （RVA） and the Brabender farinograph were used to study the pasting properties and the viscoelasticity of blends of RS （RS3 and RS2） and three wheat flours. The wheat flours represented strong gluten wheat （SGW）, intermediate gluten wheat （IGW）, and weak gluten wheat （WGW） flours, at different levels of RS substitution （0, 5, 10, 15, and 20%）. The influence of RS3 on the control wheat flours and RS-wheat flour blends were consistent with those of RS2. The peak, trough, and final viscosities of RS3-wheat flour blends were higher than those of the corresponding RS2-wheat flour blends. The peak, trough, breakdown, final, and setback viscosities ofwheat-RS blends decreased with an increase in resistant starch contents from 0 to 20% in the blends. The 0-20% RS-wheat flour blends were all able to form doughs. The dough development times, dough stabilities, dough breakdown times, and farinograph quality numbers for the RS-wheat flour blends decreased as the RS proportion in the blends increased. The values for RS-SGW flour blends were the highest, followed by RS-IGW and then RS-WGW flour blends. The water absorption values for RS-wheat flour blends and the mixing tolerance index for RS-WGW flour blends were found to increase significantly with an increasing proportion of RS from 0 to 20%, but the mixing tolerance index for RS-SGW and RS-IGW flour blends showed no significant differences amongst the different ratios. Correlation analysis showed that the Farinograph quality number was highly positively correlated with dough breakdown time, dough stability, and dough development time （r= 1.000, 0.958, 0.894）, and highly negatively correlated with the mixing tolerance index （r =-0.890）. Data from this study can be used for the development of dough-based products. It also provides a basis for RS-wheat flour blends and quality evaluation in the food industry.

Physico-Chemical Properties of Flour, Starch, and Modified Starch of Two Rice Varieties

The physical and chemical properties of the flours, starches, and modified starches of indica rice and japonica rice were investigated in this paper. Results showed that the swelling powers of flour, starch, and phosphate starch [substitution degree （DS）=0.065] of japonica rice were significantly higher than those （DS=0.065） of indica rice. The transmittance of modified starches was highest; and that of flours was lowest. The pasting property investigated with rapid visco analyzer （RVA） indicated that the peak viscosity and breakdown value of paste with high swelling power were high. Furthermore, the effect of protein and amylose content on pasting property were investigated. The results of rheological properties determined using rheological rheometer showed that at the same temperature, the storage modulus （G′ of flour, starch, and modified starch of indica rice was higher than that of japonica rice. For each variety, the G′of flour was the highest, while the G′of modified starch was the lowest.

Characteristics of Starch synthesis,Yield and Quality Provide Insights into Rice-Tartary Buckwheat Utilization and Improvement

[Objectives] Rice-Tartary buckwheat is a special type of Tartary buckwheat with easy hulling thin shell.This study was conducted to characterize the carbohydrate metabolism,quality and yield and provide a basis for food processing and breeding of rice-Tartary buckwheat.[Methods]The local rice-Tartary buckwheat‘cv.Xiaomiqiao’(XMQ) was used to explore the characteristics of photosynthesis,starch synthesis enzyme activities,traits of yield and quality,as compared to Tartary buckwheat‘cv.Jinqiao 2’(JQ2).[Results]XMQ showed significantly lower values of net photosynthetic rate,ADPGase activity and starch synthase activity at one or more periods during grain filling than JQ2.The effective branch number and grain number per plant of XMQ were similar to that of JQ2 regardless of different years,but the 1 000-grain weight was significantly lighter that resulted in the significantly lower yield.XMQ accumulated similar contents of starch(amylose,amylopectin) and protein(glutelin,albumin,prolamin,globulin) to those of JQ2,but exhibited significantly lower flavonoid content.The values of peak viscosity and hot paste viscosity in XMQ were similar to those of JQ2,but the values of cool paste viscosity,breakdown and setback were significantly lower.In conclusion,XMQ showed low yield due to the insufficient of photosynthesis and starch synthesis.XMQ exhibited high nutritional quality as well as normal Tartary buckwheat and stored 18.88 mg/g of flavonoid,that might be consumed as daily diet.[Conclusions]The present results will provide a basis for utilization and improvement of rice-Tartary buckwheat.

Physicochemical and structural properties of starches from non-traditional sources in China

In this study,we isolated starches from non-traditional sources,including quinoa,lentil,arrowhead,gorgon fruit,sorghum,chickpea,proso millet,and purple potato and investigated their morphology,physicochemical,and functional properties.Significant differences in starch particle morphology,swelling power,solubility,syneresis,crystalline pattern,and pasting viscosity were observed among the starches from these nontraditional sources.Further,all these isolated starches had unique properties because of their characteristic distinct granules when seen under scanning electron microscopy(SEM).The amylose content of the isolated starches shown significant difference(P<0.05),and the values ranged between 11.46%and 37.61%.Results demonstrated that the isolated starches contained between 79.82%to 86.56%starch,indicating that the isolated starches had high purity.X-ray diffraction(XRD)patterns of starches isolated from sorghum,proso millet,quinoa,purple potato,and gorgon fruit presented A-type diffraction pattern;while lentil seeds,arrowhead,and chickpea starches presented C-type diffraction pattern.Overall,these results will promote the development of products based on starch isolated from non-traditional starches.

Starch Digestibility and Physicochemical and Cooking Properties of Irradiated Rice Grains

This study evaluated the starch digestibility, physicochemical properties and cooking characteristics of polished rice（varieties IRGA417 and IAC202） subjected to the doses of 0（as the control）, 1, 2 and 5 k Gy of gamma radiation. The highest dose decreased the apparent amylose content, peak viscosity, water absorption and volume expansion. Irradiation increased the solid loss by 119% and 187% for IAC202 and IRGA417, respectively, when comparing the higher dose with the control. For IAC202, irradiation decreased the rapidly digestible starch and increased the slowly digestible starch（SDS） and resistant starch（RS）. IRGA417 showed an elevation of SDS and a reduction in RS. And 1 k Gy dose of gamma radiation generated the highest level of RS for both the two varieties and presented the smallest changes in other physicochemical and cooking properties.

Mechanochemical degradation of potato starch paste under ultrasonic irradiation

In the paper, changes in the molecular weight, the intrinsic viscosity and the polydispersity (molecular mass distribution) of treated potato starch paste were studied under different ultrasonic conditions which include irradiation time, ultrasonic intensity, potato starch paste concentration, and distance from probe tip on the degradation of potato starch paste. Intrinsic viscosity of potato starch paste was determined following the ASTM (American Society for Testing and Materials) standard practice for dilute solution viscosity of polymers. Molecular mass and polydispersity of potato starch paste were measured on GPC (Gel Permeation Chromatography). The results showed that the average molecular mass and the intrinsic viscosity of starch strongly depended on irradiation time. Degradation increased with prolonged ultrasonic irradiation time, and the increase of ultrasonic intensity could accelerate the degradation, resulting in a faster degradation rate, a lower limiting value and a higher degradation extent. Starch samples were degraded faster in dilute solutions than in concentrated solutions. The molecular mass and the intrinsic viscosity of starch increased with the increase of distance from probe tip. Our results also showed that the polydispersity decreased with ultrasonic irradiation under all ultrasonic conditions. Ultrasonic degradation of potato starch paste occured based on the mechanism of molecular relaxation of starch paste. In the initial stage, ultrasonic degradation of potato starch paste was a random process, and the molecular mass distribution was broad. After that, ultrasonic degradation of potato starch paste changed to a nonrandom process, and the molecular mass distribution became narrower. Finally, molecular mass distribution tended toward a saturation value.

Drag reduction by linear viscosity model in turbulent channel flow of polymer solution

A further numerical study of the theory that the drag reduction in the turbulence is related to the viscosity profile growing linearly with the distance from the wall was performed.The constant viscosity in the Navier-Stokes equations was replaced using this viscosity model.Some drag reduction characteristics were shown comparing with Virk's phenomenology.The mean velocity and Reynolds stress profiles are consistent with the experimental and direct numerical simulation results.A drag reduction level of 45% was obtained.It is reasonable for this linear viscosity model to explain the mechanism of turbulence drag reduction in some aspects.

Starch Digestibility and Functional Properties of Rice Starch Subjected to Gamma Radiation

This study investigated the effect of gamma radiation on the digestibility and functional properties of rice starch.Rice cultivars IRGA417 and IAC202 were used for isolation of starch by the alkaline method.Starch samples were irradiated with 1,2 and 5 k Gy doses of ^(60)Co at a rate of 0.4 k Gy/h.A control sample,which was not irradiated,was used for comparison.Irradiated and control starches were characterized by in vitro starch digestibility,total dietary fiber,color,water absorption index,water solubility index,syneresis,swelling factor,amylose leaching,pasting properties and gel firmness.Irradiations changed starch digestibility differently in either cultivar.Increasing radiation doses promoted increase in the color parameter b*(yellow),elevation in the capacity to absorb water,and solubility in water as well as the amylose leached from granules for both cultivars.Pasting properties showed a decrease that was proportional to the dose applied,caused by the depolymerization of starch molecules.Gel firmness of the starch from IAC202 was inversely proportional to the radiation dose applied,whereas for IRGA417,there was a reduction at 5 k Gy dose.Rice starches can be modified by irradiation to exhibit different functional characteristics and they can be used by the food industries in products such as soups,desserts,flans,puddings and others.

Acetylation of Starch Extracted from Rejected Fruits of <i>Musa ×paradisiaca L.</i>to Obtain a Pharmaceutical Disintegrant

There are many natural sources to obtain pharmaceutical grade starch, one of which is banana (Musa × paradisiaca L.);nevertheless, the use of native starch has certain disadvantages compared to modified starches, whose disintegrating properties are better. In this study, starch extracted from rejected fruits of Musa × paradisiaca L., was modified by acetylation, under the following optimized experimental conditions: 130 mL acetic anhydride, 3 mL sodium hydroxide 50% p/v for each 15 grams of native starch, at 123℃ during 3 hours. The reaction resulted in a modified green banana starch with twice as much swelling capacity compared to unmodified (native) starch;acetylation was verified by infrared spectroscopy and degree of substitution of acetyl groups by back titration. The dissolution profiles of Ibuprofen tablets made with banana modified starch and commercial disintegrant, have no differences according with their similarity factor, f2. It is concluded that it is feasible to use green banana starch modified through acetylation as a pharmaceutical disintegrant.

Study on rapid detection of irradiated rice based on RVA profile

In order to confirm whether the rice sample was exposed to gamma radiation,the changes in starch pasting viscosity of rice irradiated by different absorbed doses with additive acid solution and distilled water were investigated.The peak viscosity of irradiated rice sample was significantly decreased with the increment of absorbed doses even for the samples stored over 360 days.Irradiation samples can be distinguished from non-irradiated samples by their RVA profile as in the acid solution(pH=2.5),the starch pasting viscosities of irradiated rice samples were apparently higher while the starch pasting viscosities of non-irradiated rice samples were lower than that in distilled water(pH=7.0).The irradiation absorbed dose can be estimated accurately by the regression equation constructed with peak viscosity and absorbed doses.

稠油油藏大段塞调驱后提高采收率新技术及应用

H1块为普通稠油区块,开展多轮次调驱后,取得较好的增油效果。但随着大段塞调驱剂注入,后期压力维持在较高水平,含水率持续上升,同时注入井吸水能力下降,油井产液能力下降,产量递减加大,亟需有效开发接替技术。为进一步改善开发现状,室内设计了在大段塞调驱段塞后,注入降黏剂进一步提高采收率。室内通过大量实验,筛选出了具有良好降黏性以及界面活性降黏剂JN-1,当质量分数达到0.2%时,降黏率可达82.0%,降低油水界面张力至4.72×10^(-3)mN·m^(-1)。室内物模实验表明,在注入0.3PV调驱段塞后,继续注入0.2%降黏剂段塞0.3PV,可充分启动残余油,进一步提高采收率16.8%。现场开展降黏驱4井组先导实验,设计注入质量分数0.2%、0.14 PV降黏剂,注入后平均单井日增油0.8 t,综合含水率下降6%。

微纳米颗粒三相泡沫体系构筑及特性

为进一步提高聚驱后采收率,结合聚驱后油藏特征,构筑具有自适应堵调驱功能的微纳米颗粒三相泡沫体系,通过黏度、界面、泡沫和堵调驱性能试验,研究微纳米颗粒三相泡沫体系特性,应用归一化和权重系数方法,分析三相泡沫体系溶液特性与驱油效果的相关性。结果表明:软体微米颗粒三相泡沫体系的特性参数较好,具有超低界面张力,剖面改善率超过82%,聚驱后可提高采收率超过14%;硬质纳米颗粒三相泡沫体系的特性参数相对较差,但聚驱后仍可提高采收率超过10%;三相泡沫体系泡沫综合指数和运动黏度是驱油效果的主要影响因素,而剪切黏度和界面张力是次要影响因素。

谷物膳食纤维减缓淀粉消化性的机制研究进展

淀粉和膳食纤维同为谷物中重要的营养物质,均有益于人体健康。淀粉的消化速率和消化率是影响人体餐后血糖的关键因素,膳食纤维是一种不易被肠道吸收的营养素,因具有减缓淀粉消化的能力,近年来深受关注。本文综述了国内外关于谷物膳食纤维对淀粉消化性的影响,并从膳食纤维的黏度降低淀粉分解动力学、延迟胃排空和膳食纤维对淀粉的物理包埋以及完整细胞壁对淀粉的包裹这三个方面归纳总结了其减缓淀粉消化性的作用机制,为后续低血糖生成指数食品的创制提供理论依据。