不同品种小米粉体外消化性的测定与分析

用α–淀粉酶和淀粉糖化酶酶解消化小米粉样品,采用3,5–二硝基水杨酸比色法(DNS)测定水解过程中产生的葡萄糖,对不同品种小米粉的体外消化特性进行比较,分析淀粉水解速率,快消化淀粉(RDS)、慢消化淀粉(SDS)和抗性淀粉(RS)含量,以及RDS、SDS、RS含量与直链淀粉含量的相关性。试验结果表明:复1、济12、市售的直链淀粉含量分别为1.96%、30.58%、35.58%;快消化淀粉(RDS)含量分别为87.18%、83.41%、80.73%;慢消化淀粉(SDS)含量分别为4.128 9%、8.72%、12.97%;抗性淀粉(RS)含量分别为8.69%、7.87%、6.31%。     

蒸煮条件及回生处理对方便米饭消化特性的影响

考察蒸煮方式及回生处理对方便米饭体外消化率的影响。实验利用不同蒸煮条件及回生时间处理低直链淀粉含量和高直链淀粉含量的不同品种大米,制备得到具有不同性质的方便米饭,并研究了方便米饭快消化淀粉(RDS)、慢消化淀粉(SDS)和抗性淀粉(RS)的含量差异及其体外消化率。结果表明,相对于电饭锅蒸煮,采用常规方式蒸煮,即控制米水比为1∶1,86℃蒸煮28 min制备的方便米饭RDS含量得到极大的降低,SDS含量明显的升高(P0.05)。回生处理可以显著的降低方便米饭RDS含量。与此同时,实验发现低直链淀粉含量品种的米饭含有较低的RDS含量、较高的SDS和RS含量,高直链淀粉含量品种的米饭则含有较低的SDS和较高的RS含量。通过控制蒸煮和回生条件,可以得到淀粉消化率低的方便米饭,对肥胖及高血糖人群健康有积极作用。     

不同品种绿豆淀粉的功能特性比较研究

以9个品种绿豆淀粉为研究对象,研究了绿豆淀粉的化学组成及糊化特性、溶解度、膨胀度和冻融稳定性等功能特性,并分析了直链淀粉含量与功能特性的相关性。结果表明,不同品种绿豆淀粉直链淀粉含量不同,其分布范围为33.10%~44.08%;不同品种淀粉糊化特性参数间有明显差异;潍绿4号和中绿1号绿豆淀粉峰值粘度显著高于其他品种(p0.05),安绿8号具有最低破损值(p0.05),毛绿豆和安绿092具有较低的回生值。绿豆淀粉的溶解度和膨胀度与温度有关,均随温度的增加而增大。不同品种绿豆淀粉糊经一次冻融后析水率均较高,随冻融循环次数的增加,析水率均逐渐增大。相关性分析表明,直链淀粉含量与淀粉糊的最终粘度和回生值之间存在显著正相关(r=0.674,r=0.725;p0.05),与膨胀度之间具有极显著负相关关系(r=-0.805,p0.01)。     

不同品种马铃薯淀粉功能性质的相关性及主成分分析

分析黑龙江、甘肃、北京3个地区的11个马铃薯品种制备得到淀粉的水分含量、色泽、直链淀粉含量、透光率、碘蓝值、溶解度、膨胀度、胶稠度、质构特性。结果显示,不同品种各指标差异显著,直链淀粉质量分数的变化范围是10.96%～16.64%;相关性分析发现不同品种的各品质指标间存在显著的相关性,直链淀粉与淀粉提取率(r=0.468 3)、膨胀度(r=0.520 9)、硬度(r=-0.472 1)、咀嚼性(r=-0.449 6)分别呈显著的相关性。主成分分析结果显示,前4个主成分的特征根大于1,可以解释原有数据的信息,综合主成分得分,陇薯9号的综合值排名第一,荷兰薯的综合值最低。     

传统高温炒制工艺对裸燕麦淀粉品质的影响

通过扫描电子显微镜及X射线衍射仪观察炒制裸燕麦淀粉的形貌及晶体特征,并测定其理化特性及消化特性。结果表明：与未炒制裸燕麦淀粉相比,炒制裸燕麦淀粉的外貌及晶体特征发生明显改变,并且其直链淀粉含量明显下降,蓝值及糊化温度降低,慢消化淀粉(SDS)和抗性淀粉(RS)含量较低;而透明度及溶解度增加,易消化淀粉(RDS)含量较高,两种裸燕麦淀粉的析水率均达到50%以上。     

淀粉的消化性能与RVA曲线特征值的相关性研究

采用RVA 测定了禾谷类淀粉、块根类淀粉及豆类淀粉的黏滞性谱,并探讨淀粉的消化性能与RVA 谱特征值的相关性。结果表明,不同品种淀粉总体崩解值与易消化淀粉(RDS)呈极显著正相关(r=0.741,p ＜ 0.01),与慢消化淀粉(SDS)呈极显著负相关(r= － 0.833,p ＜ 0.01)。对于禾谷类淀粉,淀粉热糊的崩解值与RDS 呈极显著正相关(r=0.970,p ＜ 0.01),与SDS、抗性淀粉(RS)均呈显著负相关(r= － 0.906,p ＜ 0.05;r= － 0.978,p ＜ 0.01);对于块根类淀粉,崩解值与SDS 呈显著负相关(r= － 0.987,p ＜ 0.05),与RS 呈显著正相关(r=0.989,p ＜ 0.05);对于豆类淀粉,崩解值与SDS 呈负相关(r= － 1.000,p ＜ 0.05),糊化温度与RDS 呈正相关(r=0.998,p ＜ 0.05)。     

原花青素抑制玉米淀粉回生作用的研究

目的研究原花青素(OPCs)对高直链玉米淀粉、普通玉米淀粉和高支链玉米淀粉回生的影响。方法采用差示扫描量热仪(DSC)、傅立叶红外光谱仪(FTIR)、核磁共振光谱仪(NMR)测定与分析原花青素与淀粉间的相互作用;同时测定原花青素对淀粉体外消化性的影响。结果结果表明,随着OPCs含量的增加,高直链玉米淀粉回生程度降低;当OPCs添加量为5%时,原花青素对普通玉米淀粉和高支链玉米淀粉回生抑制效果较好。高直链玉米淀粉中慢消化淀粉(SDS)含量随OPCs增加而增加,普通淀粉中SDS含量在添加5%OPCs时较高,而高支链玉米淀粉的快消化淀粉(RDS)含量在5%时较高;NMR结果表明OPCs分子与直链和支链淀粉之间均存在分子间相互作用。结论添加5%原花青素对三种玉米淀粉回生抑制效果较好;原花青素对直链和支链淀粉的结合方式和结合能力不同。     

大米淀粉组成与挤压特性之间的相关性研究

分析11种大米的淀粉组成和挤压特性,探讨总淀粉、直链淀粉含量以及淀粉直/支比与膨化度、吸水性、水溶性、容重、硬度等挤压特性之间的相关性。结果表明:直链淀粉含量与吸水性呈显著正相关(r=0.879)、与水溶性呈显著负相关(r=-0.876),与膨化度之间也具有一定的相关性(r=0.530),与容重及硬度无显著相关性;淀粉直/支比与吸水性(r=0.848)呈显著正相关,与水溶性呈显著负显著(r=-0.827),与膨化度具有一定的相关性(r=0.512),但与容重及硬度无显著相关性。大米的直链淀粉含量以及淀粉直/支比与膨化度、吸水性等挤压特性具有相关性,直链淀粉含量和淀粉直/支比可作为大米挤压加工中原料选择和复配的依据。     

压热-冷却循环工艺对淀粉理化特性及消化动力学的影响

以高直链玉米淀粉和普通玉米淀粉为原料,采用压热-冷却循环工艺分别制备糊化淀粉、老化淀粉及抗性淀粉,测定各淀粉样品的理化指标及消化动力学。研究结果表明,由普通玉米淀粉经过压热处理制备的糊化淀粉和老化淀粉具有最佳的溶胀度和冻融稳定性(P0.05);老化普通玉米淀粉和老化高直链玉米淀粉中的慢消化淀粉含量显著增加(P0.05);消化动力学分析表明抗性淀粉样品中的RS含量与平衡浓度、水解指数、血糖指数呈负相关,SDS在不影响平衡浓度的情况下,能够缓慢持续释放能量。压热循环处理不仅能够显著改变淀粉的理化性质,而且改性处理后的老化淀粉和抗性淀粉能够作为脂肪模拟物得以广泛应用。     

双波长法测定小麦及小麦芽中直链、支链淀粉含量

采用双波长法对15种小麦品种的直、支链淀粉的含量进行了测定,并选择淀粉含量及支链/直链比有代表性的6个品种进行制麦试验,研究了小麦制麦芽期间淀粉含量的变化,以期探讨一种简便快捷的测定小麦及麦芽中淀粉含量的方法,并为筛选适合制麦芽小麦品种提供依据.根据碘-直链淀粉和碘-支链淀粉复合物的吸收光谱,选择直链淀粉的测定波长为631 nm和480 nm,支链淀粉的测定波长为554 nm和754 nm,依据回归方程可求出直链和支链淀粉的含量.直链淀粉的浓度在0～30μ/mL,支链淀粉在0～110μg/mL范围内符合比耳定律.制麦前后总淀粉降解程度与原小麦中支链/直链淀粉存在正相关性(P<0.1),相关系数r=0.802.     

Effect of processing on starch fractions in different varieties of finger millet

The effect of processing on starch fractions in finger millet (ragi) was studied in a standardized system and convenience mixes. In raw varieties, rapidly available starch (RDS) was 8.3% to 11.1% with slowly digestible starch (SDS) of 26.4% to 35.3%, and total available starch (TAS) 39–53%. The changes in the SDS and TAS were statistically significant. Puffing resulted in an increased RDS and decreased SDS. The changes were more prominent in hill grown varieties as compared to base varieties. Resistant starch (RS) ranged from 0.9% to 1.0% among raw varieties and decreased during puffing. The effect of puffing on gelatinisation of ragi flour was investigated, MR-1 variety showed a single phase transition with gelatinisation temperature of 64 °C, the same was found to be absent in puffed flour reflecting the gelatinisation during puffing. RS formation was influenced by the processing methods, increased during pressure cooking and roasting while dietary fiber increased during cooking and both decreased in all other processing methods. However, its implication in the convenience mix has shown that other ingredients also play a role in the RS content.     

Isolation and Characterization of Starch from Pearl Millet (Pennisetum typhoidium) Flours

Pearl millet, an underutilized crop, is a relatively good source of nutrients and has varied uses over cereals. New applications must be explored to popularize the millet. In the present study, flour and isolated starch from pearl millet cultivars—Kalukombu and Maharashtra Rabi Bajra (MRB)—were investigated for physicochemical properties, nutritionally important starch fractions and x-ray diffraction. The yield of starch was significantly low (Kalukombu: 34.5 g/100 g and MRB: 39.4 g/100 g) with traces of non-starch components (protein, fat, and ash) indicating its purity. Starch could be classified as non-waxy type based on low amylose content (2.86–4.96 g/100 g). Low amylose lead to fragility of swollen starch granules which disintegrated easily at 65°C as observed in swelling power and solubility. Isolated starch was characterized with low water- and oil-holding capacity which could be attributed to the low protein content and absence of fiber in the starch. However, MRB starch showed higher oil uptake compared to flour, possibly due to its larger surface area that increased oil uptake. X-ray diffraction patterns showed sharp peaks at 2θ values 15 and 23º and a diffused peak at 2θ of 17 and 18º which is characteristic of A-type pattern. Low resistant starch (RS) and high readily digestible starch (RDS) content observed in the isolated starch could be attributed to the A-type pattern of starch which is more susceptible to enzyme hydrolysis and also due to elimination of structural obstruction to amylase hydrolysis during the process of starch isolation and gelatinization.     

糜黍淀粉理化性质及消化特性

以黍子面和糜子面为原料,用碱法制备黍子淀粉和糜子淀粉,对其颗粒形态、红外光谱特性、透光率、溶解度、持水力、凝沉稳定性以及消化性等性质进行研究。结果表明：黍子淀粉中支链淀粉含量为91.78%,直链淀粉含量为8.21%;糜子淀粉中支链淀粉含量为65.28%,直链淀粉含量为34.72%。糜子面粉、黍子面粉及其淀粉中的抗性淀粉含量均超过50%,糜子面和糜子淀粉中的抗性淀粉含量均分别高于黍子面和黍子淀粉。黍子淀粉的透光率高于糜子淀粉。糜子淀粉凝沉稳定性强于黍子淀粉。糜子淀粉和黍子淀粉的溶解度、持水力随温度的升高,呈现上升趋势。     

糜子直链淀粉、蛋白质含量对其外观品质及食味品质的影响

以4个直链淀粉、蛋白质含量存在显著差异的糜子品种为实验材料,研究直链淀粉、蛋白质含量对糜子外观及食味品质的影响。结果表明：与低直链淀粉品种比较,高直链淀粉糜子品种,全粉糊化黏度、糊化时间、糊化温度较高,糜子饭吸水率、体积膨胀率、硬度较高,而糊化热焓值较低;蛋白质含量较高的糜子品种,全粉呈现低糊化黏度,糜子饭呈现低吸水率、体积膨胀率,高硬度。直链淀粉、蛋白质含量较高的糜子品种,蒸煮性差、能耗高、蒸煮时间长。因此,在糜子品质育种中,适当降低直链淀粉和蛋白质含量可以改善糜子的适口性。     

湿热处理对糯米粉血糖生成指数值及相关指标的影响

利用湿热处理工艺降低糯米粉血糖生成指数（glycemic index,GI）值,并对相关指标进行比较研究。通过水分含量、温度、处理时间对糯米粉直链淀粉含量和消化特性的影响,确定单因素范围,然后采用Box-Behnken设计,以直链淀粉含量（和GI值显著负相关）为指标,优化了糯米粉湿热处理工艺。最后将最优工艺所得的糯米粉（HMT）和普通糯米粉（WR）、仅进行酶解后的糯米粉（ER）进行体外消化特性和GI值的对比研究,以分析湿热处理对糯米粉GI值的影响。研究表明,经优化的最佳湿热处理时间为2.3 h、湿热处理温度为116 ℃、水分含量为20%,在优化条件下糯米粉直链淀粉含量为3.62%±0.01%,实测值均值与理论值（3.62%）一致,表明该模型可用于优化糯米粉湿热处理工艺。最优条件下制备的糯米粉快消化淀粉（rapidly digestible starch, RDS）含量下降,慢消化淀粉（slowly digestible starch, SDS）和抗消化淀粉（resistant starch, RS）含量上升;水解指数（hydrolysis index）明显降低,同时GI值降低30.1%。该法制备的糯米粉具有较低的GI值,可为低GI糯米粉开发的进一步研发提供实验思路。     

In vitro Starch Digestibility and Nutritionally Important Starch Fractions in Cereals and Their Mixtures

Dietary carbohydrates are characterized with respect to both chemical composition and likely site, rate and extent of digestion. Starch is divided into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). The present investigation aimed at evaluating the effect of starch source on nutritionally important starch fractions and the extent of in vitro starch digestion in four processed cereals, namely rice, ragi (Eleusine coracona), wheat, jowar (Sorghum vulgare) and their mixtures in varying proportions, using controlled enzymatic hydrolysis with pancreatin and amyloglucosidase. Rapidly available glucose (RAG) was also measured to derive a starch digestion index (SDI). The total starch and amylose content in the raw cereals ranged from 21 — 26.6 and 12.6 — 20.7 g/100 g, respectively. Among the four basic cereals, roti (flat, unleavened pancake, diameter 12 cm) produced from ragi had highest total starch, RDS and SDI. However, in mixtures containing two or more cereals RDS and SDI were lower than those observed in single cereals. Significant correlations were observed between RAG and SDI, or RDS, respectively (r=0.91, r=0.96, p<0.01). An inverse relation between amylose content and SDI (r= ‐0.78, p<0.01) indicates the influence of amylose on the extent of starch digestion. The results highlight the importance of starch source in determining the starch fractions of processed cereals and their mixtures. The simple in vitro measurement of starch fractions could serve as a tool for characterizing dietary carbohydrates with respect to their digestion in the gut.     

Effect of hydrothermal treatment of runner bean (Phaseolus coccineus) seeds and starch isolation on starch digestibility

The study investigated the effect of traditional soaking and cooking, storage after cooking and freezing (? 18 °C, 21 days) and autoclaving of two varieties of runner bean on starch digestibility. Results achieved were compared with digestibility of isolated starch subjected to similar treatments. The digestibility of native starch from Nata var. seeds was lower after isolation than in raw flour. This starch was characterized by a higher content of fat and lower values of swelling power (SP) and amylose leaching (AML). After the thermal treatment, a significantly higher content of rapidly digestible starch (RDS) was observed both in seeds and starch. It was accompanied by reduced contents of resistant starch (RS) and slowly digestible starch (SDS). In flours from cooked seeds, the content of RDS was observed to be higher than in flours from autoclaved seeds, despite similar changes in contents of other constituents (ash and protein). It was probably due to better starch gelatinization owing to the long-lasting soaking of seeds. This resulted in a greater decrease of amylose content of starch compared to the other flours. Differences in SP, AML and thermal properties between starches isolated from two bean varieties had no influence on their digestibility after cooking. The storage of starch pastes at a temperature of ? 18 °C, unlike that of seeds, resulted in a significant increase in RS content, which shows the importance of other flour components in the process of starch retrogradation.     

Simultaneous estimation of amylose,resistant, and digestible starch in pea flour by visible and near-infrared reflectance spectroscopy

Due to its health benefits, resistant starch (RS) has received increasing attention from the public, and there is a need to develop methods to measure the amylose and RS concentration in pea (Pisum sativum L.) flour. The aim of this study was to develop a visible and near-infrared reflectance (vis–NIR) model for the simultaneous determination of amylose, RS, and digestible starch (DS) in pea flour. A total of 123 dry pea samples consisting of different pea varieties grown in different environments were collected, and ground to flour, and then the vis–NIR spectra were scanned. The amylose, RS, and DS contents of the pea flours were also measured by an enzymatic colorimetric assay. The spectra data were calibrated with the enzymatic colorimetric-assayed values. Results showed that amylose, RS, and DS in the pea flours can be simultaneously estimated using the vis–NIR spectra. Instead of using the full spectrum (300–2300 nm), we found the most efficient wave bands lying in the visible region between 370 and 560 nm and the NIR spectra in the range of 1600–1800 nm. Using the stepwise regression with backward elimination method, the multiple linear regression (MLR) models were developed from the most efficient wavelengths. The MLR models had the determination coefficients R² of 0.95, 0.76, 0.80, and 0.88 for amylose, RS, DS, and total starch, respectively. The correlation coefficients between model estimated and the enzymatic colorimetric assayed values were 0.97, 0.80, 0.85, and 0.93 for amylose, RS, DS, and total starch, respectively.     

Chemical composition and starch digestibility in flours from Polish processed legume seeds

The study was undertaken to determine the effect of various treatments, i.e. cooking after soaking, freezing after cooking and storage at a low temperature (-18°C, 21days), and autoclaving, of Polish cultivars of bean, pea and lentil seeds on the chemical composition and starch digestibility of the resultant flours. The cooking of seeds caused a significant decrease in contents of ash (by 11-48%), polyphenols (by 10-70%) and protein (to 19%) in flours made of bean. In addition, analyses demonstrated significantly decreased contents of resistant starch, RS (by 61-71%) and slowly digestible starch, SDS (by 56-84%). Storage of frozen seeds resulted in insignificant changes in the chemical composition, and in increased contents of both RS and SDS. The flours produced upon the autoclaving process were characterized by similar changes in the contents of ash and protein as in cooked seeds, yet losses of polyphenols were lower and, simultaneously, contents of RS and SDS were higher. All the analyzed flours were shown to be characterized by a reduced content of amylose in starch, which might have affected its digestibility. This was indicated by a strict negative correlation reported between the value of the starch digestion index (SDRI) and amylose content of starch (r=0.84, p>0.05).     

不同品种糙米营养品质和理化特性比较

以7个来源于湖北省的不同品种糙米为原料,以营养组分含量、阳离子交换能力、胆固醇吸附能力、亚硝酸根吸附能力、淀粉消化特性为评价指标,研究比较糙米品种间营养品质和理化特性的差异性,旨在为糙米加工原料选择提供参考。结果表明：不同品种糙米的粗蛋白、直链淀粉、氨基酸和总酚含量差异较大,广两优香66的粗蛋白和必需氨基酸含量均最高,而罗田贡米的直链淀粉和总酚含量最高,分别为15.90%（m/m）和196.54 mg GAE/100 g DW。罗田贡米的胆固醇吸附能力和亚硝酸根吸附能力分别为 55.05 mg/g和0.20 mg/g,均显著高于其它品种糙米（P<0.05）,广两优香66和鄂中5号也展现出较强的阳离子交换能力和亚硝酸根吸附能力;巨两优60和罗田贡米的快速消化淀粉含量最低,慢速消化淀粉含量最高,具有明显延缓淀粉消化的作用。比较筛选出广两优香66（高蛋白、高赖氨酸）和罗田贡米（高总酚、胆固醇和亚硝酸根吸附能力强、延缓淀粉消化作用强）的高营养和高功能性质的品种。该研究为糙米加工及产品开发提供了数据支撑。