脱脂脱蛋白质对黑麦粉理化特性及体外消化特性的影响

黑麦是制作面包的常用原料,但是关于黑麦的消化特性鲜有报道。作者以黑麦粉为原料,制备了脱脂黑麦粉、脱蛋白质黑麦粉及黑麦淀粉;探究了蛋白质、脂肪、淀粉对黑麦粉理化特性、体外淀粉消化速率及估计血糖生成指数的影响。经不同处理后,样品在化学组成、溶解度、糊化特性等方面均有显著差异,尤以黑麦粉和黑麦淀粉之间的差异最为显著。实验结果表明黑麦粉的淀粉水解速率低于脱脂黑麦粉、脱蛋白质黑麦粉和黑麦淀粉,且脱蛋白质处理对于黑麦粉体外淀粉消化速率的影响较脱脂处理更为显著。血糖生成指数(eGI)从低到高依次为:黑麦(69.19)脱脂黑麦(76.77)脱蛋白质黑麦(79.73)黑麦淀粉(81.08)。     

不同品种大米中蛋白质和脂肪对淀粉物化特性影响的研究

以湖北省9个品种的大米作为研究对象,通过对不同品种的大米全粉、脱脂米粉和脱蛋白米粉的物化特性进行比较,研究大米中蛋白质和脂肪对大米淀粉物化特性的影响。结果表明:不同品种大米中的基本物质含量有显著差异(P0.05);脱脂、脱蛋白对大米粉的透光率有较明显的影响;脂肪和蛋白质在大米中抑制了淀粉凝沉的进行,脂肪的抑制效果更明显;蛋白质对大米淀粉的膨润力、溶解度有抑制作用,脂肪对膨润力、溶解度也有小幅度的抑制作用,但没有蛋白质的作用明显;蛋白质对大米淀粉热特性的影响较大,与糊化焓变值呈负相关关系,脂肪对大米淀粉热特性影响较小,与糊化焓变值呈正相关关系;蛋白质阻碍了大米淀粉回生的过程,而脂肪对大米淀粉回生的过程没有影响;不同来源的大米脱脂、脱蛋白处理对淀粉物化特性的影响程度存在差异。     

谷物配比对多谷物共挤压粉估计血糖生成指数的影响

以青稞、藜麦、燕麦、小米和绿豆5种杂粮为原料,采用D-最优混料设计试验,研究不同谷物配比对多谷物共挤压杂粮粉估计血糖生成指数(eGI)的影响.对比研究挤压前、后共挤压粉的淀粉、直链淀粉、蛋白质、膳食纤维等营养组分的变化情况,分析共挤压粉营养组分与eGI值的相关性.试验结果表明,谷物配比对共挤压粉eGI影响较大,eGI值...     

基于全局优化算法的杂粮eGI预测模型建立及关键影响因素分析

杂粮是我国居民膳食的重要组成部分,其营养丰富,含有多种维生素、矿物质及生物活性成分,具有调节血糖的潜在功效。杂粮的血糖生成指数（Glycemic Index,GI）受其本身理化成分影响很大,面对不同种类、不同品种、不同产地的杂粮,缺乏一种更加便捷、经济的方法进行快速初筛评价。因此,本研究以常见15种杂粮为研究对象,对其主要成分进行了分析和评价,同时测定其中多酚含量和氧自由基清除能力（Oxygen Radical Absorbance Capacity,ORAC）,采用体外模拟消化法获取其估计血糖生成指数（Expected Glycemic Index,eGI）,并通过显著性分析确定影响杂粮eGI的主要参数,进一步采用通用全局优化算法建立eGI预测模型。结果表明,杂粮比起大米具有更高的营养价值,总酚含量介于26.6~716.8 mg/100 g之间,大部分杂粮以可溶性多酚为主,多酚含量是影响氧自由基清除能力的重要原因但不是唯一因素。eGI与蛋白质（P）、膳食纤维（DF）含量和淀粉直/支比（AAR）均呈显著负相关性, eGI预测模型为：eGI=-0.080×P-1.358×DF-15.679×AAR+85.012（R2=0.77）,预测偏差为0.1%~8.7%。该模型可用于预测我国常见的杂粮的GI值,同时提示在低GI杂粮产品开发的过程中,应注意蛋白质、膳食纤维的保留,同时关注淀粉直/支比。     

杂粮原料对其挂面淀粉消化性的影响及内在因素研究

本文以五种杂粮粉为原料,通过体外模拟消化试验研究了杂粮原料对其挂面体外淀粉消化特性和估计血糖生成指数（eGI）的影响。结果表明：杂粮挂面的eGI值由高到低为：大麦>青稞>苦荞>燕麦>高粱。采用差示扫描量热仪、傅里叶红外光谱仪和X射线衍射仪等手段分析了杂粮挂面淀粉理化特性差异。高粱糊化温度和焓值显著高于其他杂粮（P<0.05）;燕麦和高粱挂面直链淀粉含量和淀粉相对结晶度较高,且具有较多短程有序结构和较强氢键强度。采用组分分离法探究了内源性酚类物质和脂肪对挂面消化特性的影响,内源性多酚和脂肪的脱除使面条淀粉消化率明显升高。该研究为开发低GI食品提供了参考依据。     

脱蛋白或脱脂对薏苡淀粉糊化和体外消化特性的影响

以薏苡为材料,制备脱淀粉颗粒相关蛋白(starch granule-associated proteins,SGAPs)、脱脂和脱SGAPs脱脂薏苡淀粉,探究了脱SGAPs和脱脂对薏苡淀粉糊化和体外消化特性的影响。结果表明,脱SGAPs和脱脂提高了薏苡淀粉的膨胀势、溶解度、快消化淀粉和慢消化淀粉,降低了1 045 cm^-1与1 022 cm^-1处峰强度比值、峰值黏度、谷值黏度、崩解值和抗性淀粉。脱SGAPs显著提高了薏苡淀粉的糊化转变温度、糊化焓,显著降低了糊化起始温度。脱SGAPs对淀粉短程有序结构和消化特性的影响大于脱脂,脱脂对薏苡淀粉的热力学性质无显著影响,脱SGAPs和脱脂对淀粉的晶型无显著影响。研究结果对于了解薏苡淀粉特性以及薏苡淀粉在食品加工中的应用具有潜在价值。     

挤压膨化及添加魔芋粉对燕麦-玉米混粉糊化特性及体外消化率的影响

本研究制备了燕麦-玉米挤压膨化粉并探究添加魔芋粉共挤压对混粉理化性质的影响,实验主要测定其基本营养成分、糊化特性和体外消化特性。结果表明,挤压膨化处理后,原料中脂肪含量和快消化淀粉含量显著降低（P＜0.05）,其中脂肪含量由9.38%降至3.06%,但对抗性淀粉含量无影响（P＞0.05）,原料粉与挤压膨化粉eGI值分别为66.03和67.34,均属于中GI物料。添加魔芋粉与燕麦玉米混粉共挤压后,不同添加量魔芋粉均能显著降低混粉中快消化淀粉含量（P＜0.05）,提高慢消化淀粉和抗性淀粉含量, 添加5%、10%、15%魔芋粉后eGI值显著降低（P＜0.05）,分别为48.06、48.51和49.11,均属于低GI物料,可作为代餐产品原料使用。     

不同油脂替代物对中式酥皮食用品质的研究

研究以聚葡萄糖、菊粉、麦芽糊精3种碳水化合物基脂肪模拟物为猪油替代物,利用色差仪、差示扫描量热仪(differential scanning calorimetry,DSC)等对中式酥皮进行品质分析,并通过体外消化实验对酥皮的淀粉组成及体外血糖生成指数进行测定。结果表明:添加油脂替代物均能降低酥皮的脂肪和卡路里含量,糊化焓显著低于纯猪油酥皮,色差值无显著性差异,抗性淀粉含量显著高于传统纯猪油酥皮,体外血糖生成指数(expected glycemic index,eGI)较纯猪油酥皮分别降低了21.15%、14.72%、15.23%,为低血糖指数中式酥皮点心的开发提供理论依据和数据支持。     

内源性成分对低GI挂面消化特性的影响

为研究内源性成分对杂粮复配低升糖指数（glycemic index,GI）挂面消化特性的影响,首先制备了以荞麦、山药、高直链玉米淀粉、小麦粉为原料的杂粮复配挂面,测定得到其GI值为53.02;在此基础上,对杂粮复配挂面的原料粉进行脱除酚类、脂类、蛋白质类、膳食纤维类等内源性成分后再分别制备成挂面,进行体外模拟消化。研究内源性成分对于挂面的淀粉水解率、蛋白消化率、结肠发酵环节的影响及作用机理。结果表明,分离内源性成分后制备的挂面,它们的淀粉水解率均明显上升,且预估升糖指数（estimated glycemic index,eGI）：脱脂挂面（68.76）>脱蛋白挂面（67.94）>脱膳食纤维挂面（63.62）>脱酚挂面（60.16）>低GI挂面（53.02）;挂面的蛋白消化率：脱膳食纤维挂面（65.04%）>低GI挂面（33.71%）>脱酚挂面（17.55%）>脱脂挂面（6.61%）;相较于小麦挂面,杂粮复配低GI挂面中的抗性淀粉显著提升了结肠发酵环节中短链脂肪酸（shortchain fatty acids,SCFAs）的含量,有助于宿主的糖脂...     

7种杂粮抗氧化活性及其挤压杂粮粉体外消化特性研究

以青稞、藜麦、燕麦、薏苡、小米、绿豆和豌豆为材料,测定了杂粮中的基本组分、多酚含量及抗氧化活性,并通过口腔-胃-小肠三段式体外模拟消化方法评价了7种杂粮经挤压处理后淀粉的体外消化速率和估计血糖生成指数(expected Glycemic Index,eGI),最后分析了抗氧化活性与多酚含量以及eGI值与基本组分之间的相关性。结果表明:7种杂粮总酚含量为19.09～128.85 mg/100 g,由高到低为绿豆、藜麦、青稞、薏苡、燕麦、小米、豌豆。藜麦中的总酚主要以游离态存在,绿豆中主要以结合态存在,其他杂粮中结合态和游离态含量相当。黄酮含量为169.58～390.11 mg/100 g,青稞、藜麦、燕麦、绿豆含量显著高于其他杂粮。青稞中黄酮类物质主要以结合态存在,且含量占总黄酮的47.39%～88.09%,其他杂粮中则主要以游离态存在。7种杂粮的抗氧化活性存在显著性差异,其中青稞清除DPPH·自由基、ABTS~+·自由基能力和总抗氧化能力最强,燕麦、绿豆次之。抗氧化能力与总酚含量相关性不明显(r=0.343),与黄酮含量有良好相关性(r=0.736)。挤压处理后,7种杂粮的eGI值由高到低为:小米豌豆藜麦燕麦绿豆青稞薏苡;其中,小米为高GI食品(82.49),其他杂粮为中GI食品(61.96～73.24)。eGI值与蛋白质(r=-0.901)和膳食纤维含量(r=-0.833)呈显著负相关,与总黄酮、直链淀粉、总酚含量和直/支比间存在一定负相关,但不显著。     

Impact of Legume Flours on Quality and In Vitro Digestibility of Starch and Protein from Gluten-Free Cakes

The aim of the study was to investigate the impact of incorporation of different legumes (chickpea, pea, lentil and bean) on quality, chemical composition and in vitro protein and starch digestibility of gluten-free layer cake (rice flour/legume flour, 50:50). The incorporation of legume flours increased the batter viscosity and, with exception of chickpea, resulted in higher specific cake volume than that in control. Chickpea and pea containing cakes had the brightest and the most yellowish crust. The legumes significantly increased the hardness and chewiness in the cakes, except with addition of lentil. Enriched cakes had higher total protein, available proteins, minerals, fat, as well as fiber content with except in the case of chickpeas. Legumes significantly affect the in vitro hydrolysis of starch fractions, decreasing the rapidly digestible starch yielding a reduction in the eGI, except chickpea containing samples. Overall, considering physicochemical properties and nutritional quality, lentil flour incorporation resulting in the best gluten-free cakes.     

In vitro starch digestibility,expected glycemic index,and thermal and pasting properties of flours from pea,lentil and chickpea cultivars

In vitro starch digestibility, expected glycemic index (eGI), and thermal and pasting properties of flours from pea, lentil and chickpea grown in Canada under identical environmental conditions were investigated. The protein content and gelatinization transition temperatures of lentil flour were higher than those of pea and chickpea flours. Chickpea flour showed a lower amylose content (10.8–13.5%) but higher free lipid content (6.5–7.1%) and amylose–lipid complex melting enthalpy (0.7–0.8 J/g). Significant differences among cultivars within the same species were observed with respect to swelling power, gelatinization properties, pasting properties and in vitro starch digestibility, especially chickpea flour from desi (Myles) and kabuli type (FLIP 97-101C and 97-Indian2-11). Lentil flour was hydrolyzed more slowly and to a lesser extent than pea and chickpea flours. The amount of slowly digestible starch (SDS) in chickpea flour was the highest among the pulse flours, but the resistant starch (RS) content was the lowest. The eGI of lentil flour was the lowest among the pulse flours.     

Physicochemical and functional properties of Caryota urens flour as compared to wheat flour

Starch digestibility, thermal, pasting and gelling properties of Caryota urens (CU) flour were investigated using wheat flour as reference. Amylose content of CU and wheat flour was 32.1% and 28.3%, respectively. CU flour had very low content of protein and lipid but had a high content of total starch (98.2%) and resistant starch (RS) [42.5%]. Gelatinisation temperature (78.5 °C) of CU flour was higher than wheat flour. Pasting behaviour of CU flour was similar to that of high swelling tuber and root and waxy starches. CU flour retrograded to a greater extent than wheat flour. Very specific gelling behaviour was noticed for CU flour where it produced significantly harder gel with high paste clarity, fracture ability, adhesiveness, gumminess and chewiness. Expected glycaemic index (eGI) of CU and wheat flour was 92.4 and 100.4, respectively. CU flour had high eGI despite high content of resistant starch.     

Physicochemical,antioxidant properties and in vitro digestibility of wheat–purple rice flour mixtures

The physicochemical characteristics, antioxidant properties and in vitro digestibility of high‐antioxidant content flours made from different combinations of Thai purple rice flour and refined wheat flour from 25%, 50% to 75% (w/w) were investigated and these were compared with whole flour from purple rice and refined wheat flour. The increase in substitution levels of purple rice flour affected all the functional properties of flours, at the same time the levels of dietary fibre, protein digestibility and antioxidant compositions were also changed. The purple rice flour exerted a particularly strong effect on starch digestibility as the purple rice increased to 50% in the mixture. Moreover, purple rice flour showed lower amounts of rapidly digested starch (RDS), whereas slowly digested starch (SDS) of whole flour from purple rice and 75% substitution purple rice flour was found to be the highest for all samples. The in vitro starch digestibility of all samples also showed a positive correlation between dietary fibre and antioxidant compounds. Overall, the addition of purple rice flour improved the final nutritional properties, notably a lower predicted glycaemic index, and a higher antioxidant potential, which are two important nutritional properties for human health.     

Potato flour as a functional ingredient in bread: evaluation of bread quality and starch characteristics

Potatoes have been added to bread for improvement of texture and moisture retention. The functional quality and starch digestibility in bread containing 5%, 10% or 15% potato flour were evaluated. Farinograph absorption of wheat and potato flour blends ranged from 59.0% to 77.7%. Bread with potato flour had significantly (P < 0.05) lower bread firmness during storage. There was a significant (P < 0.05) decrease in starch molecular weight as the level of potato flour increased. Inclusion of potato flour in these breads significantly (P < 0.05) increased the level of resistant starch (RS), while significantly (P < 0.05) decreasing the estimated glycemic index (eGI). Bread with no potato flour had 5.2% RS and an eGI of 95, while the bread with 15% potato flour had 11.3% RS and an eGI of 87. Overall, the addition of potato flour may reduce dough strength and loaf volume, but it reduced staling and increased resistant starch content of the bread.     

冰湖野米粉及其淀粉的精细结构、理化和消化特性研究

目的 探究冰湖野米粉及其淀粉的理化性质、结构特性和消化性的差异, 同时揭示不同级的冰湖野米淀粉的精细结构。方法 以3种不同级的冰湖野米和1种早籼米(对照组)为原料, 将其研磨过筛制备米粉样品, 再用焦亚硫酸钠法和甲苯法进行纯化得到对应的淀粉样品。采用体积排阻色谱分析法(Size exclusion chromatography, SEC)与荧光辅助毛细管电泳法(Fluorescence assisted capillary electrophoresis, FACE)测定冰湖野米淀粉的精细结构(直链淀粉和支链淀粉的链长分布); 利用扫描电镜、光学显微镜、X-射线衍射仪、傅里叶变换红外光谱仪和布拉班徳粘度仪等现代分析仪器对冰湖野米粉及其淀粉的理化性质和结构特性进行测定; 采用Englyst体外消化法测定冰湖野米粉及其淀粉的体外消化性。结果 研究表明, 不同级的冰湖野米粉及其淀粉的颗粒形貌特征、粘度特性、结晶结构以及直链淀粉含量无显著差异。与早籼米相比, 冰湖野米粉及其淀粉的起糊温度高, 峰值粘度低, 相对结晶度低, 热稳定性好, 慢消化淀粉和抗性淀粉含量高, 主要归因于冰湖野米的支链淀粉结构及其较高的直链淀粉含量。与冰湖野米淀粉相比, 冰湖野米粉颗粒更大, 结晶度降低, 膨胀度降低, 慢消化性增加, 主要归因于冰湖野米粉中较高的内源蛋白和纤维含量。结论 冰湖野米中的内源纤维、蛋白质、直链及支链淀粉含量对冰湖野米的粘度特性、膨胀度、结构特性以及消化性有显著的影响。     

复合湿热处理对苦荞全粉理化特性及体外消化性的影响

采用湿热处理(HM-T)、湿热复合普鲁兰酶处理(HM-E-T)、湿热复合微波处理(HM-M-T)、湿热复合柠檬酸处理(HM-C-T)4种方法,研究不同湿热处理对苦荞全粉(N-T)理化特性及消化性的影响.结果表明:经处理后苦荞全粉总膳食纤维和直链淀粉含量显著增加(P>0.05),其中HM-E-T效果最显著,HM-C-T次之;差示热量扫描仪检测结果显示,湿热处理后苦荞全粉黏度均显著降低且相变峰消失;X射线衍射结果表明,HM-T淀粉仍为A型结晶,HM-E-T淀粉由A型淀粉转变为A+B+V的多晶型,而HM-M-T和HM-C-T淀粉失去了原有晶形结构,淀粉相对结晶度从23.0％(N-T)下降至20.9％(HM-T)、18.4％(HM-E-T)、12.6％(HM-M-T)和10.6％(HM-C-T);扫描电子显微镜和激光共聚焦电子显微镜观察结果表明,处理后的苦荞全粉微观结构发生不同程度的变化,蛋白质和淀粉发生一定程度复合.体外消化结果显示,苦荞全粉中抗性淀粉质量分数从9.69％(N-T)分别增加到11.49％(HM-T)、14.12％(HM-E-T)、11.97％(HM-M-T)、13.01％(HM-C-T);预估血糖生成指数(eGI)出现不同程度的降低,即57.85(N-T)>56.03(HM-T)>55.65(HM-M-T)>55.18(HM-C-T)>50.22(HM-E-T),特别是HM-E-T后的苦荞全粉eGI值降低效果最明显.复合湿热处理比湿热处理更能有效降低餐后谷物血糖生成指数(GI)值,其中HM-E-T后的苦荞全粉可作为低GI食品的理想原料.     

3种谷物全粉中淀粉的消化性及影响因素

以常见谷物(小麦、苦荞和大米)为研究对象,采用Englyst法测定和比较了全粉、脱脂样品、脱蛋白样品及淀粉的体外消化性,并结合扫描电镜(SEM)和差示扫描量热仪(DSC)等分析仪器,从淀粉自身结构和全粉中其他组分(脂质和蛋白质)两方面,初步探讨了3种谷物全粉中影响淀粉消化性的因素。结果显示:小麦粉中脂质和蛋白质共同影响小麦粉中淀粉的消化性;苦荞粉中脂质对淀粉的体外消化性影响更明显;大米粉中蛋白质对淀粉的体外消化性影响甚微。     

芡实粉和芡实淀粉理化性质和消化性研究

以芡实为原料制取芡实粉和芡实淀粉样品,研究了其糊化性、溶胀度、可溶指数、质构性和消化性等性质.结果表明,芡实淀粉样品的黏度明显高于芡实粉样品,芡实粉的峰值黏度与芡实淀粉相比降低了57.75％;随温度升高,芡实粉和芡实淀粉的溶胀度和可溶指数呈现递增趋势,但在较高温度下,芡实粉样品的溶胀度和可溶指数明显高于芡实淀粉样品;与芡实淀粉样品相比,芡实粉的凝胶的硬度减少了91.86％;芡实淀粉样品的快速消化淀粉含量明显高于芡实粉样品,但慢速消化淀粉的含量要低于芡实粉样品,抗性淀粉的含量高于芡实淀粉样品.