A cost analysis of encapsulated spray-dried milk fat

Anhydrous butter oil or cream was encapsulated in all-purpose flour, modified cornstarch, or sucrose and then spray-dried. We estimated the processing cost for a plant designed to produce 57,000 kg/d (125,000 lbs/ d) of encapsulated milk fat powder. Powder with a 50% milk fat content could be produced for about $0.23/kg plus the cost of the butter oil or cream, the encapsulant selected, and the other ingredients. Spray-drying of milk fat improved ease of handling and reduced storage costs.     

基于模糊数学感官和响应面法研制豆渣麻花及品质分析

本文以豆渣粉和中筋粉为主要原料,辅以泡打粉、植物油、蔗糖、全蛋液进行豆渣麻花的研制.在单因素实验的基础上,利用模糊数学感官评价法和响应面优化法对影响豆渣麻花感官品质的蔗糖添加量、植物油添加量、豆渣粉添加量进行优化,并对最后成品的营养成分、理化指标和微生物指标进行相关测定.豆渣麻花的最佳工艺配方为:豆渣粉添加量14％(豆...     

Effect of osmotic pretreatment on equilibrium moisture content of dehydrated carrot cubes

The equilibrium moisture contents were determined for carrot cubes osmotically pretreated in salt, sucrose and salt plus sucrose combined solution using static method at 10, 25, 40 and 50 °C over a range of relative humidities from 14% to 95%. Six isotherm equations were applied for analysing the experimental data. Modified exponential equation, is the best equation for predicting the equilibrium moisture contents (EMC) of the dehydrated carrot cubes preosmosed in salt and sucrose plus salt solution, whereas modified Hasley equation is suitable for dehydrated carrot cubes preosmosed in sucrose solution over the relative humidity range of 14–95%. The EMC of carrot cubes osmotically pretreated with salt was highest among all pretreatments, and was lowest for un‐osmosed samples.     

Rheological and textural properties of sorghum-based formulations modified with variable amounts of native or pregelatinised cassava starch

Sorghum bread was made from native or pregelatinised cassava starch and sorghum flour in the ratio 10:90, 20:80, 30:70, 40:60 and 50:50. The other ingredients, measured on flour-weight-basis, were water (100%), sugar (6.7%), egg white (6%), fat (2%), salt (1.7%) and yeast (1.5%). The dynamic oscillatory behaviours of the batters were affected by the amount and type of starch. In the amplitude sweep measurements, increasing concentration of native starch decreased storage modulus, whereas increasing concentration of pregelatinised starch increased the linear viscoelastic range of the batters. In the frequency sweep measurements, the loss factor of batters treated with native starch declined with increasing frequency. Batters treated with 10 or 20% pregelatinised starch showed declining loss factors, whereas batters treated with 40 or 50% pregelatinised starch showed increasing loss factors with increasing frequency. Sorghum-based batters containing native starch gave bread with better crumb properties than batters containing pregelatinised starch. Crumb firmness and chewiness declined with increasing native or pregelatinised starch concentration. Crumb adhesiveness of breads containing pregelatinised starch increased with increasing starch content but was not affected by native starch. Cohesiveness, springiness and resilience increased with increasing native starch content, but were minimally affected by increasing pregelatinised starch content.     

Influence of gluten-free flour mixes and fat powders on the quality of gluten-free biscuits

Studies were conducted to develop gluten-free biscuits comparable in quality to wheat (W) biscuits and superior to those made from commercial gluten-free flour (Gf), suitable for coeliac sufferers. Three mixes of brown rice flour (R), corn starch (C), potato starch (P), soya flour (S), buckwheat flour (B) and millet flakes (M) were studied: RCPS in the percentage 70, 10, 10, 10, RPBM (50, 30, 10, 10) and RCPM (25, 25, 25, 25). Biscuits were tested for water activity, moisture, texture (snap test), diameter, thickness and colour (L* value), biscuit dough for hardness and stickiness. Various correlations >0.8 indicated for the three mixes, W and Gf that firm, non-sticky doughs yielded firm, thin, non-oval biscuits. Cluster analysis revealed that RCPS was most similar to W with regards to all parameters measured, and RCPS also showed best overall acceptability in sensory testing. Three fat powders were studied for use instead of palm oil: high and low fat dairy powder (HFP, LFP) and microencapsulated high fat powder based on vegetable fat (ME). HFP and ME yielded biscuits of comparable texture to palm oil, LFP resulted in much firmer biscuits, attributed to lower fat and higher protein and total sugar content.     

超微粉碎后粒径对大麦全粉品质特性的影响

本研究主要以大麦为主要原料,探究不同粒径对超微粉碎大麦粉品质特性的影响.研究结果表明,随着粒径的降低,大麦全粉水分、淀粉含量、溶解性、亮度值及白度值显著增加(P<0.05),而膨润力、吸油性、持水性、峰值黏度和回生值则显著降低(P<0.05).微观结构结果表明,随着粒径的降低,大麦全粉粉体的颗粒形状由圆形或椭圆形转为不...     

Functionality of batters containing different starch types for deep-fat frying of chicken nuggets

The effect of various starch types (amylomaize, corn, waxymaize, pregelatinized tapioca) on quality attributes (texture, moisture content, oil content, color, coating pick up, cooking yield, volume and porosity) of deep-fat fried chicken nuggets were studied. Chicken samples, 0.04 m in diameter and 0.015 m in thickness, taken from the breast portion, were coated with batters composed of a 3:5 solid to water ratio by immersion. The solid content of batter formulations contained equal amounts of corn and wheat flour, 5.0% starch, 1.0% salt and 0.5% leavening agent. As control, batter without starch addition, was used. Samples were fried at 180°C for 3, 6, 9 and 12 minutes. Crispness and oil content of chicken nuggets increased, whereas moisture content decreased with increasing frying time. Starch addition to the formulations increased crispness of the product significantly at the last stages of frying. The highest porosity and oil content was obtained when corn starch was used. Pregelatinized tapioca starch was found to provide a product with the lowest oil content, the highest moisture content, coating pick up and volume.     

莲子淀粉重组米制备工艺优化

以不同比例莲子淀粉与碎米粉进行混合后挤压制备重组米,通过对混合粉的糊化特性和重组米的感官品质、质构特性及蒸煮损失率的分析,确定了莲子淀粉重组米的配比。以物料含水量、模头温度、螺杆转速为影响因素,采用响应面试验优化了莲子淀粉重组米挤压的最佳工艺条件。结果表明:随着莲子淀粉添加量的增加,混合粉的峰值黏度、谷值黏度、崩解值、最终黏度及回生值等均逐渐增加;感官评分先增大后减小,在莲子淀粉添加量为30%时较高;质构特性中硬度逐渐增大,弹性、咀嚼性、黏聚性先增大后减小,在莲子淀粉添加量为30%时最大;蒸煮损失率逐渐增大。综合分析,重组米品质在莲子淀粉添加量为30%时达到最佳。重组米的最佳挤压条件为:物料含水量40%、螺杆转速210 r/min、模头温度95 ℃时,重组米评分为69.13分。     

INFLUENCE OF HYDROXYPROPYL METHYLCELLULOSE ON THE RHEOLOGICAL AND MICROSTRUCTURAL CHARACTERISTICS OF WHOLE WHEAT FLOUR DOUGH AND QUALITY OF PURI

Puri is a traditional unleavened fried product prepared from whole wheat flour. Hydroxypropyl methylcellulose (HPMC) was used to study its effect on rheological characteristics of whole wheat flour dough and puri making quality. Addition of HPMC at 0.5 and 1.0% w/w increased the water absorption and dough stability whereas the resistance to extension and extensibility decreased. Pasting temperature, peak viscosity and cold paste viscosity gradually decreased. The moisture and fat contents of puri increased marginally. Quality parameters and sensory acceptability were monitored after 0 and 8 h of storage. Addition of 0.5% HPMC gave higher sensory scores. Microscopic observations during puri processing showed that the starch granules in the control dough were clearly visible in the protein matrix, which reduced on frying due to partial gelatinization. Microstructure of puri with HPMC showed higher gelatinization of starch. It also helped in moisture retention and hence, resulted in highly pliable and soft-textured puri .

PRACTICAL APPLICATIONS

Puri is a traditional unleavened fried product that is prepared by mixing whole wheat flour and water, sheeted to a desirable thickness and fried. Use of hydroxypropyl methylcellulose (HPMC) affected the whole wheat flour dough and puri making quality. It helped in moisture retention and hence, resulted in highly pliable and soft-textured puri . Microstructure of puri with HPMC showed higher gelatinization of starch.     

Improving Adhesion of Seasonings to Crackers with Hydrocolloid Solutions

Food powders were applied on crackers that had been coated using water, oil, emulsion, sucrose, or hydrocolloid solutions. The hydrocolloids that were used include gellan gum, kappa‐carrageenan, methylcellulose, gum karaya, gum tragacanth, gum arabic, guar gum, modified starch, and maltodextrin. Solutions of similar hydrophobicity to the powder gave the greatest adhesion. NaCl, barbecue (BBQ), ranch, and sour cream & onion (SC&O) seasoning showed greatest adhesion with water, cheese powder with an emulsion of 12.5% to 25% oil, and cocoa powder with oil. For NaCl, BBQ, ranch, and SC&O seasoning, hydrocolloids improved the adhesion over using water alone, with gellan gum providing the greatest adhesion. Hydrocolloid structural differences, including the presence or absence of branching, substitution of sugar units, and molecular weight affect water binding and thickening of the hydrocolloid spray that seemed to be significant factors affecting adhesion of powders to the target surface. For cheese powder, hydrocolloids were capable of replacing the oil within an emulsion while improving or maintaining the same level of adhesion, with gum arabic providing the greatest adhesion. For cocoa powder, hydrocolloid solutions were ineffective adhesives due to differences in hydrophilicity that result in insolubility. The effect of hydrocolloid concentration on adhesion was dependent both on the hydrocolloid type and the concentration that is sprayable, with 0.5% being the optimum concentration for most gums. Adhesion using sucrose solutions was determined by particle size and relative hydrophobicity. Increasing sucrose concentration decreased adhesion of smaller particles, but increased adhesion of larger particles. Adhesion of NaCl significantly increased with decreasing NaCl size using oil, water, and sucrose solutions.     

Influence of heat–moisture treatment and annealing on functional properties of sorghum starch

Sorghum starch was annealed in excess water at 50 °C for 24 h. Starch was also modified under heat–moisture treatment at 110 °C after adjusting various moisture contents (20, 30 and 40%) for 8 h. Significant decrease in chain lengths of amylose fraction in HMT starches was observed. Heat moisture treated (HMT) and annealed (ANN) starches showed lower granule sizes, swelling power, peak and setback viscosity but higher retrogradation as compared to native starch. HMT starch with addition of 40% moisture showed a decrease in relative crystallinity. HMT and ANN starch gels were observed to be harder than native starch gel.     

Single-Screw Extrusion of Defatted Soy Flour, Corn Starch and Raw Beef Blends

Effects of feed moisture, fat and corn starch levels and process temperature on physical properties of extrudates of defatted soy flour-amylose corn starch-raw beef blends were investigated using response surface methodology. Contour plots showed a convex curve of expansion ratio (ER) with moisture, concave curves of bulk density (BD) and shear-force (SF) with moisture, and concave cmves of SF with each of the four extrusion variables. Fat decreased ER and increased BD, whereas corn starch increased ER. Products with high ER and low BD and SF tended to have prominent air cells, continuous protein matrices, and smooth cell wall surfaces in scanning electron micrographs. The optimum extrusion conditions for minimal SF values, with 20% non-dehydrated beef muscle and varied amounts of defatted soy flour, were: 29.1% feed moisture; 2.96% feed fat; 22% feed corn starch; and 162°C process temperature.     

Pregelatinised amaranth flour as an ingredient for low-fat gluten-free cakes

This work explored the use of pregelatinised amaranth flour (PAF) as an oil substitute in the preparation of amaranth cakes. Amaranth flour was extruded to achieve approximately 50% gelatinisation, ground and sieved. The PAF was used to replace the oil in the cake preparation at levels 33, 66% and 100%. FTIR analysis of the cake formulations showed that PAF modified the molecular organisation of starch and proteins. The starch showed more hydrated structures, although less ordered. The proteins exhibited a significant reduction in the β structures and a marked increase of the side chains, probably caused by the interaction with amaranth starch. The in vitro digestibility of starch showed a slight increase with the addition of PAF. The slowly digesting starch fraction showed a visible decrease, reflecting the presence of starch chains more accessible to amylolysis. Instrumental texture revealed an increase (P < 0.05) in cake hardness with the addition of PAF, particularly for medium (66%) and high (100%) oil replacements. Sensory analysis showed that the perceived texture, flavour and colour were negatively affected by the addition of the pregelatinised flour. Overall, the sensory analysis indicated that cakes with low levels of PAF oil replacement may be acceptable to consumers.     

Physical Properties of Encapsulated Spray-Dried Milkfat

Spray-dried encapsulated milk fat powders were prepared from stable emulsions containing 40-60% milk fat and carbohydrate matrices. Moisture content of the spray-dried powders varied from 1-4%. Lowest free fat content (<10%) was found in powders with 40% fat, encapsulated in sucrose. Angles of repose ranged from 37 to 46°, and correlated with powder flow (p = 0.01). Bulk density was dependent on the encapsulant and declined with increasing fat content. Product density did not influence powder recovery through the cyclone of the dryer. Particle size distribution ranged from 20 to 120 μm with 80% of the particles < 100 μm. Powders with best physical properties were made with 40-50% butteroil encapsulated in sucrose.     

Improving the nutritional quality and maintaining consumption quality of akara using curdlan and composite flour

Soybean flour and curdlan were incorporated into cowpea flour to determine their effect on lowering the fat content and on the physical properties of akara. At 20% substitution, soybean flour lowered the fat content of akara by 7.7% and increased the protein content by 28.7% without significantly affecting the firmness or the colour of akara. Addition of 1% curdlan decreased the fat content by 32.2% but significantly increased the firmness of akara and produced a darker‐coloured product. The paste moisture content of akara containing 20% soybean flour and 1% curdlan was modified to obtain product characteristics comparable with the control (100% cowpea flour) while maintaining a lower fat content. Optimum results were obtained for paste with 63% moisture content. Firmness of this modified product was similar to the control and the fat content was lower (17%) compared with the control (26%).     

Lactose crystallization delay in model infant foods made with lactose, beta-lactoglobulin, and starch

Handling and storage alter infant food powders due to lactose crystallization and interactions among components. Model infant foods were prepared by colyophilization of lactose, β-lactoglobulin (β-LG), and gelatinized starch. A mixture design was used to define the percentage of each mixture component to simulate a wide range of infant food powders. The kinetics of crystallization was studied by a gravimetric method (dynamic vapor sorption) at 70% relative humidity (RH). After freeze-drying, lactose was amorphous and crystallized at 70% RH. The delay before crystallization depends on the contents of β-LG and starch in the formulations. A mathematical model was proposed to predict crystallization time (delay) at 70% RH. For the formulation containing 50% lactose, 25% β-LG, and 25% starch, lactose was still amorphous after 42 h at 70% RH, whereas pure amorphous lactose crystallized after approximately 70 min. Calculated and experimental results of adsorbed moisture from the formulations were compared. Adsorbed water of formulation containing lactose could not be calculated from moisture sorption properties of each component at a given RH because β-LG and gelatinized starch prevented lactose crystal growth.     

Modification and properties of African yam bean (Sphenostylis stenocarpa Hochst. Ex A. Rich.) Harms starch I: Heat moisture treatments and annealing

African yam bean (Sphenostylis stenocarpa) starch was subjected to heat moisture treatments at 18% (HMT-18), 21% (HMT-21), 24% (HMT-24), 27% (HMT-27) and excess (Annealing) moisture levels. Proximate chemical composition of the starch samples revealed that the moisture content of the starches ranged between 6.7% and 12.5%. Following modification of the native starch, there was a reduction in the moisture level of the heat moisture treated starches from HMT-18 to HMT-27. However, the annealed starch (HMT-ANN) retained higher moisture content compared to native starch (AYB-Native). The carbohydrate, protein, ash, amylose and fat content reduced with all the forms of heat treatments. At the temperature range studied (60–90 °C), increasing level of heat moisture treatments reduced the solubility and swelling capacity. pH also exert a profound effect both on the solubility and the swelling of the starch. Increasing degree of alkalinity increased both solubility and swelling capacity. In the native and modified starch samples, replacement of the wheat flour by the starch resulted in increased alkaline water retention of the blends. Water absorption capacity of the starch increased with the severity of moisture treatments, while the oil absorption capacity decreased. Apart from HMT-18, there was improved gel forming capacity of all the other heat-modified starches.Pasting temperature increased after hydrothermal modifications, whereas peak viscosity (P_v), Hot Paste Viscosity (H_v), setback and breakdown values all reduced after heat moisture treatments. All the starches were of type-B viscosity.Differential scanning calorimetry studies revealed that heat moisture treatment shifted the onset temperature (T_o), peak temperature(T_p) and conclusion temperature (T_c) to higher values. The gelatinisation temperature of the annealed starch was comparable to native starch. In addition, gelatinisation band of the native starch increased progressively from HMT-18 to HMT-27. Heat moisture treatment reduced the gelatinsation enthalpy (ΔH), while the enthalpy of retrogradation(ΔH_r) increased with the storage time of the gelatinised starch. Retrogradation enthalpy of the heat moisture conditioned starches were lower than the value obtained for the native starch.X-ray diffraction studies of the starch indicated that all the starch samples showed the type-C diffraction pattern. Differences were however observed in their degree of crystallinity. Native starch exhibited the lowest crystallinity (20%) while annealed starch had the highest crystallinity (27%)Microscopy studies revealed surface indentation, formation of groves in the central region, folding of starch granules and formation of doughnut-like appearance in some of the starch samples.     

Effect of Different Raisin Juice Preparations on Selected Properties of Gluten-Free Bread

Incorporation of sucrose and raisin juice (in concentrated or in dried form) at 3 and 5% of flour weight to commercial wheat starch (Codex Alimentarius) gluten-free flour was carried out to examine the effects on baking, textural, and sensory properties of bread. Breads made with gluten-free flour are usually characterized by poor color and baking characteristics, as well as short shelf life. The current study was conducted to help solve these problems by using raisin juice, a natural sweetener that contains no preservatives, has lower caloric content than sucrose, and includes a number of important vitamins and minerals that are very important for the coeliac disease patients. The study showed that 3% raisin juice in concentrated form contributes to a great improvement in loaf volume, color, and hardness characteristics of gluten-free bread during the first day after baking but a higher staling rate because of its high moisture content. Dried raisin juice gave bread higher loaf volume and better color compared to the control gluten-free bread and also increased its shelf life because of its moisture absorption properties. Sensory analysis revealed a preference for breads containing concentrated raisin juice because of its fruity flavor, whereas all the samples that contained 5% raisin juice had very dark color.     

青稞全粉与中筋小麦粉复配体系品质特性研究

选用青稞全粉作为研究对象,与中筋小麦粉复配,检测不同添加量青稞全粉的损伤淀粉特性、粉质特性、糊化特性、溶剂保持力,并进行相关性分析。研究表明:随着青稞全粉比例增加,破损淀粉显著增加(P<0.05),且与降落数值呈显著负相关;面团的吸水率呈上升趋势,当青稞全粉添加量为85%时面团的吸水率达到最大值73.10%,吸水率、弱化度显著增加(P<0.05);不同添加量对混合粉稳定时间的影响不显著;峰值黏度、最低黏度、最终黏度、衰减值、回生值显著下降(P<0.05),降落数值与峰值黏度呈极显著正相关;乳酸溶剂保持力SRC显著减少(P<0.05),湿面筋含量和乳酸溶剂保持力SRC呈极显著正相关;碳酸钠溶剂保持力SRC、蔗糖溶剂保持力SRC、水溶剂保持力SRC显著增加(P<0.05),破损淀粉值与碳酸钠溶剂保持力SRC,蔗糖溶剂保持力SRC与吸水率、蛋白质,水溶剂保持力SRC与蛋白质均呈极显著正相关性。