Comparative properties of cakes prepared from rice flour and wheat flour

Received: 20 September 1999     

Physicochemical properties of flour recovered from broken rice noodles during production

Flour recovered from broken rice noodles was evaluated by microscopy, X‐ray diffractometry, differential scanning calorimetry, in vitro starch digestibility, pasting and gel texture analyses. Rice noodle making processes destroyed the granular and crystalline structures of rice flour (RF), but the process‐induced recrystallised amylopectin and amylose‐lipid complexes were observed. Higher level of resistant starch in broken rice noodle flour (BRNF) was due to the retrograded amylose, which formed during noodle making. The absence of pasting temperature and low pasting viscosity of BRNF were distinct from those of RF, whereas gel textures of both flours were similar. BRNF‐added rice noodles showed lower hardness, but the other cooking and texture qualities were close to the one without BRNF. Up to 17% of BRNF could be incorporated into composite rice noodle making. This study thus provided an approach to the management and utilisation of food processing wastes.     

鱼糜米粉丝的研制

介绍了鱼糜米粉丝的制作工艺,并对影响鱼糜米粉丝的色、香、味、粘度、柔韧性等的因素进行了探讨.通过反复试验得出生产鱼糜米粉丝的最佳原料配方及生产工艺.     

Production of high-fructose rice syrup and high-protein rice flour from broken rice

The objective of this study was to develop a process for the production of both high-fructose rice syrup and high-protein rice flour from broken rice. The rice flour was obtained from broken rice by using either a dry or wet milling method. The glucose produced from the slurry of various raw materials by treating with α-amylase and glucoamylase was compared. Results indicated that cassava and corn starch were better raw materials than rice flour. However, the filtered residue of liquefied rice slurry could be recovered as high-protein rice flour. The particle size of rice flour had a small effect on the glucose yield. The orthogonal-array table (L₂₇) method of experimental design was employed to determine optimum conditions for liquefaction. The glucose yield based on starch was 90.8±3.6% under the following optimum conditions α-amylase, 0.12%; rice flour, 20%; temperature, 96°C; time, 90 min. The filtrate from liquefied rice slurry was saccharified at 60°C with three different concentrations of glucoamylase. The higher the enzyme concentration, the shorter the time required to reach the maximum yield. After saccharification, the glucose solution was decolourised, desalted and concentrated to 40% d.s. and then isomerised to fructose at 60°C under continuous operation by using immobilised glucose isomerase packed in a column. The isomerised syrup was then purified and concentrated to 71% d.s. The final high-fructose rice syrup contained 50% glucose, 42% fructose and 3% maltose. After liquefaction, the rice slurry was centrifuged and the precipitate was dried by either spray or drum drying. The composition of these two high-protein rice flours was almost the same and the protein content was about three times as high as the raw material. There were significant differences in surface structure of rice flour and high-protein rice flours, as observed by the scanning electron microscope.     

谷氨酰胺转氨酶对挤压糙米粉面团蛋白特性和面条品质的影响

将挤压糙米粉(EBR)与小麦粉以1∶1(m/m)的比例混合制成面条,研究了谷氨酰胺转氨酶(TG)添加量(0.5%、1.0%和1.5%)对面条性质的影响。结果表明,TG添加后,面条中游离巯基含量减少,SDS-PAGE条带显示面条中形成了大分子质量的聚集体。随着TG的添加,面条最佳蒸煮时间增加,干物质损失率降低,吸水率升高。添加量为1.0%时,面条最佳蒸煮时间和吸水率达到最大值,蒸煮损失率达到最小值。TG添加量为0.5%时,面条的硬度、耐咀性、回复性和剪切力最大。扫描电镜结果显示,TG的添加明显增强了面条内部结构的连接与聚合,面条内部变得更加紧实,连续性增强。TG添加量为0.5%~1.0%时,挤压糙米粉面条质构品质和蒸煮品质较好。     

紫薯-小麦混合粉的性质及在面条上的应用

紫薯全粉保留了鲜薯的色泽和营养,是极好的食品加工原料,能够弥补小麦粉营养结构单一的缺点。将紫薯粉添加到小麦粉中,对混合粉的特性及在面条上的应用进行了研究,结果表明：随着紫薯粉的添加量由0%增加到30%,混合粉的糊化温度由66.31℃上升至67.73℃;糊化黏度、崩解值和回生值均减小;面团稳定时间由18min下降至7.8min;紫薯面条煮沸损失率由7.2%上升至11.8%;最大拉伸应力、剪切应力及硬度均减小;面条色度变暗,色泽向紫红色渐变。紫薯粉最佳添加量为15%。     

Functional,digestibility, and antioxidant properties of brown and polished rice flour from traditional and new‐improved varieties grown in Sri Lanka

Sri Lankan traditional and improved rice varieties were processed into brown and polished rice flours. Samples were analyzed for AM, protein, lipid, total phenolic content, and antioxidant activity. Gelatinization and retrogradation properties were observed in the Rapid Visco Analyzer (RVA) and DSC. The AM content of the samples was high to intermediate (20 to 26%) except for one which was low (17%). Brown rice flour (BRF) samples had lower swelling power, lower RVA viscoamylograph profile, lower gel hardness, lower gelatinization enthalpy but higher gelatinization peak temperature and lower melting enthalpies of its retrograded AP relative to its corresponding polished rice flour (PRF) samples. The BRF showed a lower decrease in peak viscosity in the RVA viscoamylograph as compared to its PRF when treated with α‐amylase indicating inhibition potential. The traditional rice varieties had 68 to 86% higher total phenolic content (TPC) and 86 to 90% antioxidant activity in the BRF samples as compared to the improved varieties. A study on the antioxidant profile of the brown rice of the traditional rice varieties is being undertaken to explore their value as functional foods.     

干法、半干法和湿法磨粉工艺制备的糙米米线品质研究

采用干法、半干法和湿法3种方式将糙米磨粉制备糙米米线,干法粉碎强度10～40 Hz,半干法调节含水量为20%～35%及湿法料液比为1∶1、1∶2、1∶3、1∶4,研究了3种磨粉方式对糙米米线蒸煮品质和质构性质的影响,并分析了糙米磨粉颗粒细度及损伤淀粉含量与糙米米线蒸煮品质的相关性。结果表明,磨粉方式及磨粉工艺条件显著影响糙米米线的蒸煮、质构和感官品质,糙米磨粉颗粒细度与糙米米线最佳蒸煮时间显著正相关,与糙米米线断条率显著负相关。糙米磨粉损伤淀粉含量与糙米米线最佳蒸煮时间、硬度显著负相关,损伤淀粉含量与糙米米线断条率显著正相关。干法粉碎强度10、半干法水分调节含量20%、30%和35%、湿法粉碎料液比1∶3～1∶4时,糙米米线的品质较好。     

Fatty acids composition and rheology properties of wheat and wheat and white or brown rice flour mixture

Manufacturing of bread from rice flour only presents technological difficulty because the rice is gluten-free and gluten is the most important structure forming protein. By using wheat and rice flour mixture, this problem can be avoided, and end product is enriched by rice-oil constituents. In this paper fatty acids composition, with an emphasis on total saturated, and total unsaturated fatty acids, rheological and baking properties of wheat–rice flour mixture (70:30 w/w) were investigated. The results show that wheat–rice flour mixture has better fatty acids composition with higher content of stearic, arachidic, lignoceric, oleic, and phthalic acids compared to wheat flour. Also, wheat flour did not include myristic, arachidic, lignoceric and linolenic acids, so rice flour addition made fatty acids profile richer as number of constituents is higher, nine instead six. The content of total unsaturated fatty acids content was higher in wheat–brown rice flour mixture than in wheat flour and in wheat–white rice flour mixture. When rice flour was added to wheat flour the rheological properties were changed: flour mixture had less water absorption, less degree of softening, longer development time, higher gelatinization temperature, but better stability and finally, better quality number and group than wheat flour. So, the wheat and rice flour mixture can be considered as a good quality flour and can be used for making good quality wheat-rice bread and cake.     

原料生粉的物理性状对鲜湿切粉品质的影响

以直链淀粉和蛋白质含量差异显著的3种籼稻精米为研究材料,通过调浆(料液质量比11.5)进入产能为1 200kg/h现代机切湿米粉生产线加工成鲜湿切粉,运用扫描电镜、激光粒度仪、DSC扫描量热仪和质构仪等分析了普通干法粉碎、气流超微粉碎和水磨法粉碎的原料生粉物理性状,以及与鲜湿切粉品质的关系。结果表明,不同方法制备的精米粉体粒径大小差异显著(P<0.05),水磨粉表面光滑、呈多面体,颗粒小而均一、平均粒径5.5～7.6μm,微粉颗粒(≤15μm)占比达65.2%～79.1%,糊化焓值为6.7～7.0J/g,在现有的生产工艺条件下,原料生粉的直链淀粉含量,原料生粉在水浆中的粒径水平、粒径组成特性和分散均匀性是制约鲜湿切粉品质的关键因素;800目以上粒径的颗粒组分比例越高,鲜湿切粉品质越好,硬度10g左右、黏力0.5～0.8g、弹力0.4～0.5g可作为鲜湿切粉品质指标的重要参考;原料生粉的糊化特性、蛋白质和脂肪含量等是影响鲜湿切粉品质的次要因素。     

发芽糙米粉理化性质研究

对发芽粳糙米粉和发芽籼糙米粉基本成分、微观结构、热焓特性及糊化性质(RVA)等进行了研究。结果表明:与糙米粉相比,发芽糙米粉中粗脂肪含量降低,蛋白质含量增加,总淀粉含量降低,粗纤维、灰分等含量变化不明显;随着发芽时间的增长,糙米粉峰值粘度、最低粘度、崩解值、最终粘度和回升值都降低;发芽糙米粉峰值温度、起始温度、终止温度及焓值均比糙米粉低,且籼糙米高于粳糙米。扫描电镜结果显示:发芽后糙米粉颗粒结构变得较疏松,棱角不太明显,发芽籼糙米粉颗粒结构较发芽粳糙米粉颗粒结构更加疏松,淀粉颗粒体积更小。      

米粉对面团流变特性及酥性饼干品质的影响

目的 探究了米粉的添加对面团流变学特性以及酥性饼干品质的影响。方法 选取了3种米粉(粳糯米粉、籼糯米粉、普通粳米粉)分别以0%、10%、20%、30%的比例替代中筋小麦粉，研究分析了米粉-中筋小麦粉混合粉的糊化特性，面团的粉质拉伸特性，动态流变以及酥性饼干的理化性质，质构特性及感官品质。结果 随着两种糯米粉添加量增加，混合粉的糊化特征值均呈下降趋势，而添加普通粳米粉后则趋势相反；添加米粉后混合面团的吸水率和弱化度随着三种米粉的添加量的增加显著升高，分别可达65.7%和160.50，而面团形成时间和稳定时间则显著降低(P<0.05)；混合面团的弹性模量（G''），黏性模量（G"）和损耗角正切值（tanδ）随着米粉添加量的增加而逐渐减小，表明米粉的添加减弱了面筋网络的形成；与低筋粉酥性饼干相比，混合粉酥性饼干的延展比较低，且三种米粉的添加可显著提升酥性饼干的脆性，经感官评价及综合比较后得出添加20% 籼糯米粉的混合粉饼干整体品质较佳。结论 通过在中筋面粉中加入米粉后可以有效改变面团的特性，以替代低筋面粉应用于酥性饼干的加工 ，本研究也为米粉在酥性饼干专用粉的制备奠定了理论基础。     

不同储藏时间米糠制备膳食纤维对米粉糊化和凝胶性质的影响

将米糠储藏0、1、3、5、10 d后制备的米糠不溶性膳食纤维(rice bran insoluble dietary fiber,RBIDF)添加到米粉中,研究不同储藏时间米糠制备的RBIDF对米粉糊化和凝胶性质的影响。结果表明,当RBIDF添加量相同时,随着米糠储藏时间的延长,米粉的峰值黏度呈先上升后略微下降的趋势,在米糠储藏第5天时达到最大值,回生值逐渐上升,峰值时间和糊化温度先下降后上升,分别在米糠储藏5 d和3 d达到最小值;储能模量在米粉凝胶形成阶段和米粉凝胶形成后阶段都呈上升趋势,损耗角正切在米粉凝胶形成后阶段先减小后增大,在米糠储藏5 d达到最小值;硬度、回复性、胶着性、咀嚼度先增大后减小,黏附性先减小后增大,均在米糠储藏3 d达到极值。相关性分析结果表明,米糠毛油酸值与米粉的峰值黏度呈显著(P 0. 05)正相关,与峰值时间和糊化温度呈极显著(P 0. 01)负相关,与回生值和米糠储藏时间呈极显著(P 0. 01)正相关。     

Studies on suitability of wheat flour blends with sweet potato,colocasia and water chestnut flours for noodle making

Blends of refined wheat flour (RWF) with colocasia (CF), sweet potato (SPF) and water chestnut (WCF) flours respectively at replacement level of 25 g/100 g were assessed for their suitability for noodles making. All the native flours as well as their blends with RWF exhibited restricted swelling behavior. Incorporation of SPF or CF into RWF decreased the peak viscosity of flour blends. Noodles prepared from respective flour blends of SPF and CF with RWF showed lower cooking time, higher cooked weight, higher water uptake and higher gruel solid loss in comparison to control sample (RWF noodles). Among blend flours noodles, RWF and SPF blend noodles were rated superior for their organoleptic/eating characteristics of slipperiness, firmness, appearance but undesirable high value of tooth packing. Noodle with acceptable quality characteristics and decreased level of gluten, which may prove beneficial for celiac persons, can be developed using RWF blends with non-conventional flours like colocasia, sweet potato and water chestnut.     

基于AGDS和静态消化模型的全麦面条体外消化特性研究

采用动态(人工胃模拟系统,AGDS)和静态(振荡水浴)2种体外消化模型,分别对全麦面条的消化特性进行考察,探究不同消化模型在全麦面条消化特性研究中的差异,对消化过程中pH、胃排空情况、粒径变化、淀粉水解和蛋白质胃内降解进行表征。结果表明：全麦面条在AGDS模型胃消化阶段的颗粒降解程度高于静态模型,这可能是由于AGDS模型对胃内机械力的模拟有利于促进全麦面条食糜的物理破碎。全麦面条淀粉组分在2种模型的胃消化阶段均发生少量水解,当小肠消化结束时,静态和AGDS模型的淀粉水解率分别为66.51%和53.49%。同时,全麦面条蛋白质组分在静态消化模型胃消化阶段的水解速度快于AGDS。     

Effects of potato starch on the characteristics,microstructures and quality attributes of indica rice flour and instant rice noodles

The effects of partial replacement (0%–20%, w/w) of rice flour by potato starch (PS) on the physicochemical properties, microstructures, texture and in vitro digestibility of indica rice flour (IRF) and instant rice noodles (IRN) were systematically investigated. Accordingly, the addition of PS significantly increased the peak viscosity (2876.00–3221.00 mPa·s) and tan δ values (0.14–0.22) but lowered the setback values (2169.00–1036.50 mPa) of the pastes. Rice noodles with 5%–15% PS (PS and IRF at the mixing ratios of 5:95, 10:90, 15:85 and 20:80, respectively) addition exhibited modulated appearance and textural properties. The mutually exclusive phosphate groups of PS facilitated the expansion of starch granules, contributing to the formation of more compact microstructure and higher-ordered crystalline structures (confirmed by scanning electron microscope and X-ray diffraction), endowing rice noodles with better cooking and digestive attributes, and visibly increased slowly digestible starches content (26.09%–31.34%). The quality attributes of rice noodles could be accurately predicted by the physicochemical properties of rice flour referring to Pearson’s correlation analysis. The study demonstrates that the blending of PS is both an effective and economical pathway in improving the nutritional and textural properties of IRN.     

Impact of brown foxtail millet (Setaria italica) flour on thermo-mechanical properties of flours from different rice varieties

The physical, functional and thermo-mechanical properties of rice flours prepared from long, round and medium rice grain and of foxtail millet (Setaria italica) flour were investigated. The impact of foxtail millet flour addition on the thermo-mechanical properties to the rice flours was also explored. Rice flour from long grain had higher amylose content (26.37%), while the rice flour from round grain had better hydration properties compared to the other rice flours. The dough from long grain rice flour exhibited higher starch gelatinisation temperature and cooking stability and lower starch retrogradation compared to the other investigated rice flours. Foxtail millet flour addition to the rice flours exerted a lower impact on the thermo-mechanical properties of the dough based on rice flour from long grain compared to the other investigated rice flours. These differences might be due to the differences in terms of starch properties and proximate composition of the flour samples.     

Effect of blending of raw and steamed wheat flour on the rheological characteristics of dough

 The blended dough made from raw wheat flour and wheat flour steamed for 15 min at a ratio of 1 : 1, along with minor ingredients (salt, oil) showed reduced farinograph water absorption capacity. The stability of the blended dough with oil was reduced while the mixing tolerance index increased. The inclusion of salt in the blend increased the resistance to extension and also the area under the curve. The hardness and cohesiveness measured by means of texture profile analysis decreased with the inclusion of oil in the blend, while increasing with the addition of salt. The Rapid Visco Analyser used to measure pasting characteristics showed a peak viscosity which increased for the blend with salt, but decreased for that with oil. Similarly, the hot paste viscosity, cold paste viscosity and area under the curve increased for the blend with salt, but decreased for the blend with oil. Received: 5 February 1999 / Revised version: 21 April 1999     

Effects of milling on functional properties of rice flour

ABSTRACT:  A commercial long-grain rice flour (CRF) and the flours made by using a pin mill and the Udy mill from the same batch of broken second-head white long-grain rice were evaluated for their particle size and functional properties. The purpose of this study was to compare the commercial rice flour milling method to the pin and Udy milling methods used in our laboratory and pilot plant. The results showed that pin milled flour had more uniform particle size than the other 2 milled flours. The chalky kernels found in broken white milled rice were pulverized more into fines in both Udy milled flour and CRF than in the pin milled flour. The excessive amount of fines in flours affected their functional properties, for example, WSI and their potential usage in the novel foods such as rice breads (RB). The RB made from CRF collapsed more than loaves made from pin milled Cypress long-grain flours.     

浅谈糯米淀粉的性状及应用

将不同添加量（0%~25%）的木糖醇添加至糯米粉中构建木糖醇-糯米粉共混体系,探讨木糖醇对糯米粉的糊化特性、热力学特性、凝胶质构、流变学特性和消化特性等性质以及对其制成的汤圆品质的影响。结果表明：木糖醇的添加使共混体系的糊化温度、峰值黏度和终值黏度有所提高,体系的短程有序程度降低,体系表现为假塑性流体,具有剪切稀化行为。与对照组相比,木糖醇添加量为10%时,共混体系的回生值和凝胶硬度最小,分别为405 cP和14.952 g,体系抗性淀粉含量为29.88%,表现出较好的抗回生性。但高浓度木糖醇（15%~25%）促进体系发生短期回生,增加其回生值和弹性。另外,木糖醇的添加显著降低了汤圆的冻藏水分损失率和汤汁透过率,其中添加10%的木糖醇制成的汤圆具有更高的硬度、弹性、回复性以及咀嚼性,食用品质最好。本研究为木糖醇改善糯米粉品质以及糯米粉产品开发提供参考。