Evaluation of the quality characteristics of flour and pasta from fermented cassava roots

The study investigated the effect of fermentation of cassava roots on the quality characteristics of flour and pasta. Cassava roots were fermented under natural condition for a period of 12, 36 and 60 h. Physicochemical properties, microbial analysis, pasting properties, in vitro digestibility, X-ray diffraction analysis of cassava flour, cooking properties, texture profile analysis (TPA) and sensory properties of the pasta were examined. The moisture content, carbohydrate, water absorption capacity, swelling and solubility index of fermented flour increased with an increase in fermentation period. Also, as fermentation progressed, increase in pasting viscosities of cassava flour was observed. The resistant starch (RS) content of cassava flour decreased with increasing period of fermentation. The duration of fermentation process significantly affected textural properties and cooking loss of cassava pasta. Sensory assessment showed that cassava roots fermented for 36 h gave pasta with the most acceptable qualities.     

Gel Textural Characteristics of Corn,Cassava and Yam Starch Blends: A Mixture Surface Response Methodology Approach

Blends of native starches can be used to obtain special sensory properties avoiding the use of chemically modified starches. The mixture design approach was used to analyze the textural properties (hardness, adhesiveness, cohesiveness and gumminess) of gels obtained with different proportions of yam, corn and cassava starches (6% total solids) and related to microstructural characteristics. Maximum limits of 60% yam starch and 70% corn starch and minimum level of 30% cassava starch were fixed to minimize syneresis under storage. Hardness, adhesiveness and gumminess increased with the proportion of corn starch in the blends. The lowest values of hardness corresponded to the blends containing higher proportions of cassava starch, that has the lowest amylose content. Corn starch was the component that less contributed to cohesiveness. The characteristic high cohesiveness of cassava starch pastes (related to its higher amylopectin content) was reduced when it was mixed in adequate proportions with yam and/or corn starches. Gels containing only yam starch presented syneresis values close to 40% after 24° h storage at 4°C; the decrease of the maximum level of yam starch to 60% as well as the inclusion of cassava starch in the blends reduced weight losses. Disadvantages found in gels containing individual starches, such as exudate in yam and corn starch gels, and excessive cohesiveness in cassava starch gels, are minimized improving their possible applications, when blends are used.     

不同乳化剂对糯米糕品质的影响及抗老化研究

以糯米粉、粘米粉为原料制作糯米糕,以感官评定与质构分析为指标,研究不同食品乳化剂对糯米糕品质的影响及抗老化效果。结果表明:单一乳化剂对糯米糕品质的改善均有一定的作用,单独添加蔗糖脂肪酸酯(sucrose fatty acid ester,SE)0.60%、单硬脂酸甘油酯(glyceryl monostearate,GMS)0.20%、羟丙基二淀粉磷酸酯(hydroxypropyl distarch phosphate,HPDSP)0.60%和硬脂酰乳酸钠(stearic acid sodium lactate,SSL)0.20%时对糯米糕品质改良效果最理想。在7 d、4℃贮藏过程中,SE、HPDSP和SSL对糯米糕均有不同程度的抗老化效果,其中添加量分别为SE(1.20%)、HPDSP(0.70%)和SSL(0.20%)时抗老化效果最好,而GMS则抗老化效果不明显;4种食品乳化剂中SE(1.20%)的抗老化效果明显优于其他3种。     

Effect of hydrocolloids and emulsifiers on the rheological,microstructural and quality characteristics of eggless cake

Effect of hydrocolloids like Arabic (AR), guar (GR), xanthan (XN), carrageenan (CG) and hydroxypropylmethylcellulose (HPMC) in combination with emulsifiers such as glycerol monostearate (GMS) and sodium stearoyl-2-lactylate (SSL) on the rheological, microstructural and quality characteristics of eggless cake was studied. Addition of GR to wheat flour in the presence of SSL increased peak viscosity, while in the presence of GMS all hydrocolloids excepting XN increased the peak viscosity. The set back value decreased with the addition of hydrocolloids. Addition of hydrocolloids to wheat flour as well as in the presence of GMS and SSL increased the eggless cake batter viscosity, specific gravity, and XN showed the highest value. Among different hydrocolloids tried, only HPMC improved the eggless cake making characteristics of wheat flour. Use of HPMC increased the overall quality score of eggless cake with GMS to the maximum extent followed in decreasing order by CG and XN. Addition of all the hydrocolloids increased the overall quality of eggless cake with SSL and highest improvement was brought about by HPMC. Microstructure studies of eggless cake crumb with hydrocolloids showed that the starch granules appeared wrapped by XN and HPMC. In eggless cake with combination of HPMC and SSL the protein matrix appeared more uniform.     

Influence of surfactants on rheological characteristics of dough and quality of parotta

The effect of the surfactants glycerol monostearate (GMS), lecithin, diacetyl tartaric acid esters of monoglycerides (DATEM), polyoxyethylene sorbitan monostearate (PS‐60) and sodium stearoyl‐2‐lactylate (SSL) on the rheological characteristics of dough and quality of parotta was studied. Use of the surfactants increased stability as measured by the farinograph, valorimeter value, extensograph ratio figure and extensograph area, indicating an increase in the strength of the dough. Surfactants reduced the mixograph peak height, mixograph area, apparent biaxial extensional viscosity, compressive stress, force decay parameter, hardness and adhesiveness, and increased the cohesiveness of dough. The values for peak viscosity increased with DATEM, PS‐60 and SSL and decreased with GMS and lecithin. Among the surfactants tested, SSL and PS‐60 brought about the greatest improvement in the quality of parotta, followed in decreasing order by DATEM, lecithin and GMS.     

EFFECT OF SURFACTANT GEL AND GUM COMBINATIONS ON DOUGH RHEOLOGICAL CHARACTERISTICS AND QUALITY OF BREAD

Sodium stearoyl‐2‐lactylate (SSL), diacetyl tartaric acid esters of monoglyceride (DATEM), glycerol monostearate (GMS) and distilled glycerol monostearate (DGMS) surfactant gels were made with water. Addition of surfactant gels decreased water absorption by the bread while xanthan, karaya, guar and locust bean gums increased the same. Only DGMS or GMS and gum combinations further improved water absorption. All the gums except for guar along with surfactant gels improved dough stability. Both surfactant gels and gums improved the extensograph dough properties of wheat flour to varying degrees. Alveograph characteristics of wheat flour improved to varying extents with surfactant gels while the gums influenced the viscoelastic properties in differing ways. Different combinations of surfactant gels and gums showed varied influences on rapid visco analyzer characteristics of wheat flour. Both surfactant gels and gums improved the bread making quality. Among surfactants, SSL in combination with gums, and among gums locust bean in combination with surfactant gels improved the bread making quality of wheat flour to a maximum extent.     

豆酱自然发酵过程中蛋白质和氨基酸的变化规律

为研究豆酱在自然发酵过程中蛋白质、氨基酸组成及含量的变化规律,以按照东北豆酱传统方法制作的自然发酵豆酱为研究对象,在检测蛋白质含量、氨基氮含量、氨基酸含量、非蛋白氮含量和水解指数等指标变化的基础上,对豆酱的氨基酸评分(amino acid score,AAS)、化学评分(chemical score,CS)、必需氨基酸指数(essential amino acid index,EAAI)进行分析。结果表明,豆酱蛋白质含量、非蛋白氮含量、蛋白水解指数先上升后下降;氨基氮含量则先不断增加后减少至稳定。自然发酵豆酱中共含有17种氨基酸,但不同发酵时期豆酱中氨基酸含量差异较大,成品豆酱中氨基酸总量维持在41.00 mg/g左右,明显高于生豆粉(11.42 mg/g)和熟豆粉(11.06 mg/g)中氨基酸总量。不同发酵时期豆酱中必需氨基酸与非必需氨基酸的比值在0.48~0.77之间,提示豆酱中的蛋白质为优质蛋白。分析不同发酵时期豆酱的AAS、CS和EAAI可知,发酵20 d时EAAI最高达29.41,发酵50~75 d豆酱的EAAI保持在16.16~17.40之间。通过比较4种呈味氨基酸的含量可知,甜味氨基酸苦味氨基酸鲜味氨基酸无味氨基酸。     

毛霉发酵对豆制品的质构和微观结构的影响

利用质构仪和扫描电子显微镜研究毛霉发酵豆腐的质构和微观结构,通过电泳分析豆腐的蛋白质水解情况,并与未发酵豆腐进行对比。结果表明,与未发酵豆腐相比,发酵豆腐的硬度和黏性增大,内聚性和弹性减小。其微观结构较均匀致密。电泳分析和微结构分析均显示出大分子量的蛋白质在豆腐发酵过程中的降解。     

Texture properties of formulated wheat doughs Relationships with dough and bread technological quality

Texture properties of wheat doughs were determined with a texturometer by using texture profile analysis (TPA) as well as Chen and Hoseney methodologies. The time elapsed between two compressions and strain were optimized so that meaningful values were obtained for TPA. Single effects and interactions between flour type, the breadmaking process and anti-staling additives (i.?e. monoglycerides, diacetyl tartaric ester of monoglycerides, sodium stearoyl lactylate, carboxymethylcellulose and hydroxypropylmethylcellulose) on dough texture properties (i.?e. springiness, resilience, hardness, cohesiveness, adhesiveness, chewiness, gumminess and stickiness) were estimated. The breadmaking process and addition of hydrocolloids had the most important effects and interactions on TPA. Hydrocolloids and α-amylase increased dough stickiness. Dough cohesiveness was a good predictive parameter of bread quality. Water content, acidity values and gluten quality were the main factors determining the texture properties of dough.     

天然马铃薯、木薯和玉米淀粉添加对发酵挂面品质的影响

为解决市售发酵挂面存在爽滑性差、粘弹性差、蒸煮时间长的问题,本文以单因素实验的方法,研究了马铃薯淀粉、木薯淀粉和玉米淀粉对发酵挂面蒸煮特性、质构特性以及感官评价的影响。结果表明:添加天然薯类和谷物淀粉均可以改善发酵挂面的蒸煮及质构品质,提高感官评价得分,尤其能够缩短最佳蒸煮时间,同时结合质构和感官实验数据分析,添加10%木薯淀粉对发酵挂面品质的改善最佳。添加10%木薯淀粉后发酵挂面的蒸煮损失和最佳蒸煮时间显著降低（P<0.05）,蒸煮损失降低率和最佳蒸煮时间缩短率分别达到30.18%和18.73%,面条的煮后硬度、咀嚼性和回复性显著提高（P<0.05）,感官评价得分也得到提升（87.2分）。本研究对提升发酵挂面品质有一定的实际意义。     

乳化剂对热风干燥方便面品质的影响

研究了硬酯酰乳酸钙钠(CSL-SSL)、硬酯酰乳酸钠(SSL)、蔗糖酯(SE)、单甘酯(GMS)和硬酯酰乳酸钙(CSL)5种常用乳化剂对热风干燥方便面的吸水率、蒸煮损失、最大拉伸力、TPA特性(硬度、胶着性、咀嚼性)、剪切硬度的影响。结果表明,SSL、CSL-SSL对热风干燥方便面的品质影响效果最明显,SSL和CSL-SSL的最佳添加量为0.2%。     

发酵方式对玉米粉品质和风味特性的影响

以未经发酵的玉米粉为对照,对自然发酵、植物乳杆菌、酿酒酵母菌及复配菌种（植物乳杆菌和酿酒酵母菌）发酵制得的玉米粉品质进行分析。结果表明：相比未发酵玉米粉,发酵后玉米粉中粗蛋白、粗脂肪、粗纤维和粗灰分含量显著降低（P<0.05）,总淀粉含量显著上升（P<0.05）;发酵使玉米粉的糊化温度显著升高（P<0.05）,自然发酵和复配菌种发酵后的玉米粉衰减值和回生值显著降低（P<0.05）,玉米粉的稳定性和抗老化性能提高;植物乳杆菌和复配菌种发酵对玉米粉的微观结构影响较大;酿酒酵母菌和复配菌种发酵产生的香气和代谢产物有效改善了发酵玉米粉的不良气味。通过不同发酵方式的对比得知,植物乳杆菌、酿酒酵母菌和复配菌种发酵可以将玉米粉自然发酵所需的13 d分别缩短至72、18 h和48 h,有效提高了生产效率。经复配菌种发酵后制得品质、风味且加工性能更加优良的玉米粉。     

Rice flour — A functional ingredient for premium crabstick

This study was performed to evaluate rice flour as a functional ingredient for premium crabstick and develop a commercially viable recipe. Physicochemical properties of crabstick pastes with 42% surimi, with various rice flour concentrations (0, 1, 3, and 5%), and other ingredients were evaluated. The physical properties were measured during refrigeration and frozen storage. Rice flour measured at various concentrations (5 to 40% in water) using a DSC demonstrated similar patterns with an endothermic peak at around 63.5°C. During refrigerated storage, the strength of gels increased gradually, while cohesiveness stayed mostly unchanged. During frozen storage, water retention ability (WRA) gradually decreased as freeze-thaw (F/T) cycles were extended, however the water reduction was minimized as rice flour concentration increased. The optimum level was 1% rice flour concentration for chilled and frozen crabstick. Two crabstick samples (control and 1% rice flour) demonstrated no difference in strength and cohesiveness.     

CHANGES IN LIPIDS DURING FERMENTATION OF CASSAVA FLOUR

During the incubation of cassava flours with or without yeast, there was an increase in the lipid with the mobility of diglyceride. Glycolipids were metabolized during the fermentation as evidenced by 17% less of hexose in the lipids. Linolenic acid fell from 11% in unincubated flour to 7% in the fermented flour. Palmitoleic acid which was a major yeast fatty acid was absent in the fermented product.     

Functionality Enhancement of Composite Cassava Flour in the Production of Maize Tuwo (A Non-fermented Maize-Based Food Dumpling)

The study was focused on the evaluation of textural and sensory quality enhancing functionality of cassava flour in the production of maize tuwo (a non-fermented maize-based food dumpling). The cassava flour was added to maize flour at the level of 5%, 10%, 15%, 20%, 25% and 30% (w/w), respectively. The bulk density and water holding capacity of maize/cassava flour mixes ranged from 0.77–0.83 g/cm³ and 1.91–2.05 g/g, respectively, while those of 100% maize flour were 0.84 g/cm³ and 2.09 g/g, respectively. There were variations in the pasting properties of maize/cassava flour mixes including the pasting temperature (75.4–78.8°C), peak viscosity (112.1–170.0 RVU), breakdown viscosity (38.4–53.7 RVU) and final viscosity (132.1–142.2 RVU), while those of 100% maize flour were 74.6°C, 108.1 RVU, 38.1 RVU and 148.3 RVU, respectively. The colour characteristics of tuwo prepared from maize/cassava flour mixes showed an increase in the colour lightness, L*-value (68.6–71.8) and chroma, C-value (9.4–11.4) while tuwo from 100% maize flour gave 67.7 and 9.1, respectively. The cohesiveness indexes (15.4–24.2%) of tuwo from maize/cassava flour mixes increased with an increase in the quantity of cassava flour in the mix while that from 100% maize flour was 15.2%. The softness indexes (17.5–18.4°mm) of tuwo from the mixes were also higher than that from 100% maize flour (17.4°mm). The sensory quality rating of tuwo from maize/cassava flour mixes showed that tuwo from 25% cassava flour inclusion was the highest in terms of texture (hand-mouldability), taste and overall acceptability while that from 30% cassava flour inclusion was the highest in terms of colour.     

The pasting behaviour of lactic‐fermented and dried uji (an East African sour porridge)

The effects of sun‐, cabinet‐, and drum‐drying on the behaviour of submerged culture lactic‐fermented pure cassava, maize and finger millet and composites of maize–finger millet and cassava–finger millet were investigated in a Brabender amylograph. The cereal flours and maize–finger millet composite had higher onset and peak gelatinization temperatures but lower peak viscosities than cassava or cassava–finger millet composites. Fermentation alone or in combination with drying increased the viscosity of the flours, except for the fermented and drum‐dried cassava–finger millet composite flour. This increased viscosity of uji on fermentation and drying makes it more difficult to cook. Fermented and drum‐dried flours recorded high initial viscosities, at 30 °C, when the amylograph was switched on. Copyright © 2003 Society of Chemical Industry     

不同萃取方法提取青稞老酵馒头挥发性成分的比较

该研究采用顶空固相微萃取（HS-SPME）法和同时蒸馏萃取（SDE）法提取青稞老酵馒头样品中的挥发性风味物质,采用气相色谱-质谱（GC-MS）法对其进行检测,比较不同提取方法对青稞老酵馒头挥发性成分的提取效果。结果表明,两种方法提取物中共检测到91种挥发性化合物,共同检出成分为7种。其中HS-SPME法提取物中共检测到63种,以醇类、醛类、烯烃类为主;SDE法提取物中共检测到35种,以醇类、醛类、酮类、酯类、羧酸类为主。两种方法提取的青稞老酵馒头挥发性风味物质差异明显,且HS-SPME法提取物中检测出的挥发性风味物质数量高于SDE法。说明两种方法各有优劣,相互补充,结合分析可为青稞老酵馒头挥发性成分的鉴定提供更全面、完整的信息。     

Production of high energy density fermented uji using a commercial alpha-amylase or by single-screw extrusion

The effects of alpha-amylase and extrusion on the viscosity and energy density of uji, a spontaneously fermented thin porridge from different combinations of maize, finger millet, sorghum and cassava, were investigated. Fermentation alone was not able to reduce the viscosity of uji, but addition of 0.1-2.1 ml/100 ml alpha-amylase to the fermented slurry or extrusion of the fermented and dried flour at 150-180°C and a screw speed of 200 rpm reduced the viscosity of 20 g/100 ml uji from 6000-7000 to 1000-2000 cP, measured at 40°C and a shear rate of 50 s⁻¹. The amount of flour required to make uji could thus be increased by a factor of 2.0-2.5 and consequently it was possible to produce uji with acceptable energy densities (0.6-0.8 kcal/g) for child feeding.