Sunflower Oil–Water–Cellulose Ether Emulsions as Trans-Fatty Acid-Free Fat Replacers in Biscuits: Texture and Acceptability Study

A new vegetable, and trans-fatty acid-free, fat replacer consisting of a sunflower oil–water–cellulose ether emulsion was employed to replace 100 % of the shortening in a short dough biscuit recipe, and the dough and biscuit texture properties were evaluated. In comparison to the shortening dough, the cellulose emulsion dough was significantly (p?<?0.05) softer and more elastic. However, the cellulose emulsion biscuits had higher spreadability, implying that the increase in dough elasticity was not affecting this property, probably because of the decrease in dough hardness. Although the cellulose emulsion biscuits contained 33 % total less fat than the shortening biscuits, their instrumental texture properties were very similar, implying that the cellulose emulsion avoids the increase in hardness associated with fat reduction. This was associated with the thermal gelation ability of the cellulose ethers, which develops during baking. The overall consumer acceptance was significantly (p?<?0.05) higher in the shortening biscuits, but their scores were very similar to those of the cellulose emulsion biscuits (maximum difference 1.1/9 points).     

Understanding the Effect of Sugar and Sugar Replacement in Short Dough Biscuits

Sucrose is the main sugar used in short dough biscuit formula, and it plays an important role in the biscuit manufacturing as well as in the biscuits final quality. However, for health reasons, high levels of sucrose are undesirable, making sucrose replacement an important issue to study. The present study focused on sucrose reduction and its replacement by polyols (erythritol and maltitol) in short dough biscuits. The effects were investigated in a model system composed of gluten and different sugars (sucrose, maltitol, and erythritol), in biscuit dough, and in baked biscuits. Modulated thermal analysis showed that sucrose decreases the glass transition temperature; however, for both polyols studied, no transition was found due to a plasticization effect. The gelatinization of starch in the biscuits was not affected by the sugar or quantity of sugar used. Temperature sweeps of short dough revealed that the presence of sugar delays the transitions. Furthermore, G* increased with sucrose replacement, with the smallest changes for the maltitol-containing biscuits compared to the control. Finally, texture and dimension analyses were carried out. Sugar-free and erythritol-containing biscuits were compact, elastic, and resistant to the breaking force compared to the control biscuits and the maltitol-containing biscuits.     

Ingredient Functionality in Multilayered Dough-margarine Systems and the Resultant Pastry Products: A Review

Pastry products are produced from heterogeneous multilayered dough systems. The main ingredients are flour, water, fat and sugar for puff pastry, and the same plus yeast for fermented pastry. Key aspects in pastry production are (i) building laminated dough containing alternating layers of dough and bakery fat and (ii) maintaining this multilayered structure during processing to allow for steam entrapment for proper dough lift during baking. Although most authors agree on the importance of gluten and fat for maintaining the integrity of the different layers, detailed studies on their specific function are lacking. The exact mechanism of steam entrapment during dough lift and the relative contribution of water set free from the fat phase during baking also remain unclear. This review brings together current knowledge on pastry products and the factors determining (intermediate) product quality. Its focus is on flour constituents, fat, water, and (where applicable) yeast during the different production stages of pastry products. Future research needs are addressed as the knowledge on biochemical and physical changes occurring in flour constituents and other ingredients during pastry production and their effect on product quality is currently inadequate.     

TEXTURAL AND VISCOELASTIC CHANGES OF CANNED BISCUIT DOUGH DURING MICROWAVE AND CONVENTIONAL BAKING

Textural changes of canned biscuit wheat dough during microwave and conventional baking were described and contrasted using empirical methods. Drastic increases of specific volume and modulus of elasticity were observed in the beginning and the ending periods of both baking processes. Weight loss showed a significantly (p < 0.001) linear relationship with baking time for both baking methods, but the weight loss rate constant for microwave baking was 0.36%/s significantly (p<0.01) higher than conventional baking. Multi-dimensional Scaling showed that microwave baking for 50 s best resembles the textural characteristics of wheat dough under conventional baking for 10 min. Stress relaxation modeling indicated that microwave baking produced higher viscosity and modulus of elasticity values which translates into baked biscuits with undesirable tougher texture.     

DEVELOPMENT OF DYNAMIC MODULUS AND CELL OPENING OF DOUGH DURING BAKING

The dynamic shear modulus (elastic and viscous modulus) development of dough during baking was studied. Flooded parallel plate geometry was used to monitor the rheological changes of commercially available canned doughs (bread dough, bun dough and biscuit dough). The normal force exerted on the upper plate by the expanding dough was measured to study the cell‐opening event. The dough‐baking process was simulated in a rheometer oven. The morphology of baked dough was studied using a scanning electron microscope to elucidate the effect of ingredients and process parameters on the properties of the final baked product. Three stages of modulus development were observed during the baking process: bubble growth and packing, rapid expansion/starch gelatinization and final curing. The cell opening coincided with the sudden rise in modulus caused by starch gelatinization. The rate at which starch gelatinization takes place controls the temperature of the cell opening. The type and concentration of various ingredients have a greater effect on the modulus and on the cell opening than the heating rates. Frequency dependence was observed during baking, but the effect on modulus development diminished at higher frequencies.     

The role of gluten proteins in production and quality of a yeast leavened sugar and fat rich wheat based food model system – 2. Impact of redox agents

The present paper studies the impact of gluten polymerization on the quality of yeast leavened sugar and fat rich developed dough model systems. This was done using an approach based on the use of the redox agents l-cysteine and potassium iodate, and N-ethylmaleimide to selectively alter the properties of the wheat gluten proteins in such model systems. Despite the high levels of sugar and fat in the system, redox agents affected dough expansion during fermentation and protein polymerization during baking. The data suggest that both gluten development during mixing and subsequent polymerization during baking are related to dough expansion and shrinkage and determine product dimensions. The extent of gluten polymerization determines spread rate during baking and product dimensions. Increased protein polymerization during baking yields firmer products.     

Effect of native and germinated finger millet flour on rheological and sensory characteristics of biscuits

Wheat flour was replaced with native finger millet flour (NFMF) and germinated finger millet flour (GFMF) at 30–50% levels to make soft dough biscuits. Dough rheological properties and baking characteristics of the blends were evaluated. Farinograph data of wheat flour replaced with NFMF and GFMF showed a decrease in water absorption, dough stability and an increase in mixing tolerance index as the level of replacement increased. Extensibility of dough decreased for both NFMF and GFMF as the levels increased. The hardness of biscuit dough measured by texture profile analysis increased from 125 to 234 N for NFMF and 118 to 126 N for GFMF. Scanning electron microscopic studies on the biscuit dough showed polygonal finger millet starch granules adhering to wheat starch granules and protein matrix. The results of the study indicated that the replacement level of 40% with either NFMF or GFMF produced biscuits with acceptable sensory attributes. Addition of sodium stearoyl‐2‐lactylate (SSL) showed further improvement in terms of spread ratio, surface characteristics and texture.     

Impact of endogenous constituents from different flour milling streams on dough rheology and semi-sweet biscuit making potential by partial substitution of a commercial soft wheat flour

A flour fractionation-reconstitution procedure was used to study the substitution of a commercial soft wheat flour with gluten, water extractables, prime starch and starch tailing fractions isolated from patent and clear flour streams on dough rheology and semi-sweet biscuit characteristics. Substitution of soft wheat flour with increasing levels of the native patent and clear flour streams raised the dough consistency, hardness and elastic properties as well as the biscuit textural attributes (density, hardness). The dough stickiness of the base flour was also reduced and the biscuits were free of cracks. Gluten isolated from the patent flour had a greater impact on dough consistency, hardness and elastic properties than gluten obtained from the clear flour, likely due to the superior protein quality of the former. Additionally, with increasing gluten levels in the fortified flour there were moderate increases in biscuit density, hardness, and lower crunchiness. The addition of starch tailings produced the largest impact on consistency and hardness of the dough. This fraction also exerted a pronounced effect on biscuit density and hardness, while it lowered crunchiness, presumably due to its higher pentosan content. Overall, the dough rheological properties and biscuit characteristics were controlled by the amount-nature of the fractions added; i.e., besides gluten (amount and quality), other constituents such as pentosans and the overall composition of the flour blends can largely affect the quality of the semi-sweet biscuits.     

Influence of natural antioxidants and their carry‐through property in biscuit processing

BACKGROUND: The present study has explored the use of natural antioxidants from plant sources such as hexane (G‐1) and chloroform (G‐2) extracts of Garcinia, Peltophorum ferrugineum flower extract (FE), turmeric powder (C‐1) and curcumin (C‐2), in biscuit preparation in the place of synthetic ones, and their carry‐through properties were evaluated during processing and storage. Microstructure and electrophoretic characterization of biscuit dough were carried out to understand the influence of these natural antioxidants in the processing of biscuits. RESULTS: Biscuits prepared with C‐1, C‐2, G‐1, and G‐2 were well acceptable, and FE biscuits were least acceptable. Among the antioxidants used, C‐2 was found to retain only 11.23% activity whereas G‐2 had retained 51% activity after baking, which was comparable to synthetic antioxidant butylated hydroxyanisole (BHA) and better than tert‐butylhydroquinone (TBHQ). Microstructure studies of biscuit dough indicated that in the case of G‐1, G‐2, C‐1 and BHA the gluten network formation was intact when compared to FE and TBHQ. Supportive electrophoresis studies indicated that there was no change in the wheat protein subunits of different samples except for FE biscuit dough. CONCLUSION: Based on the result of retention of antioxidant activity during baking and storage, hexane and chloroform extracts of Garcinia (G‐1, G‐2) and turmeric powder (C‐1) were found to be suitable for use in biscuits as natural antioxidants and results were comparable with BHA. The present study also indicated that protein subunits of biscuit dough were not affected by antioxidants. However, antioxidants influenced the protein–starch–lipid network during biscuit dough formation. Copyright © 2008 Society of Chemical Industry     

A stability study of green tea catechins during the biscuit making process

A green tea extract (GTE) was incorporated into biscuit as a source of tea catechins. The stability of tea catechins in the biscuit making process was studied. A method was developed for the separation and quantification of tea catechins in GTE, dough, and biscuit samples using a RP-HPLC system. GTEs at 150, 200, and 300 mg per 100 g of flour were formulated. The results obtained showed that green tea catechins were relatively stable in dough. The stability of (−)-EGCG and (−)-ECG was determined at an interval of every 2 min during baking. Their stability decreased as the baking progressed and increased as the concentration of GTE was increased in the biscuit dough. The stability of (−)-EGCG also increased as pH of the dough was reduced and made less alkaline.     

Compositional and varietal influence of finger millet flour on rheological properties of dough and quality of biscuit

Biscuits prepared from flour composites containing 60:40 and 70:30 (w/w) finger millet:wheat flour were evaluated for its dough characteristics and biscuit quality. Hardness of biscuit dough measured by textural profile analysis was more in 60:40 combination than in 70:30 level. The dough became more adhesive with higher level of wheat flour and it varied across varieties. Extensograph data also showed that resistance of biscuit dough increased with the increasing levels of wheat flour. However, very little difference was observed between addition of 30 and 40 g/100 g wheat flour in terms of resistance to extension. Wheat composite flour (40 g/100 g) had higher water absorption capacity than in 30 g/100 g composite flour. Bandwidth of composite flour was narrower in 40 g/100 g wheat flour composite. Expansion of biscuit and breaking strength after baking was more in 70:30 composite than in 60:40. Among the varieties used, VL-324 brought about the positive changes of composite flour in rheological characteristics in terms of adhesiveness, extensibility and resistance to extension, which in turn improves biscuit quality. It provided better physical quality biscuit dough and biscuit in terms of its spread ratio, density and breaking strength. Studies indicated that composite of finger millet and wheat flour (60:40) was found better, particularly in case of biscuit quality. Out of six varieties, VL-324 was found best in terms of biscuit quality as well as acceptability.     

Biscuit baking by near-infrared radiation

Measurements of the transmission of monochromatic near-infrared (NIR) radiation by two formulations of biscuit dough, a hard sweet dough (Rich Tea) and a soft cookie dough (Chocolate Chip Cookie), showed maximum transmission at wavelengths of 1·0–1·2 μm. At wavelengths above 2·5–3·0 μm, transmission was so small as to be indistinguishable from instrument noise.Using quartz-tungsten tubes emitting radiation of peak wavelength (λ_p) 1·2 μm it was found that a wide range of biscuit products (crackers, semisweet and short dough types) could be baked on the usual type of baking support (wire mesh or continuous steel band) in approximately half the time required in a conventional oven. The products from the two types of baking process were closely similar in appearance, physical dimensions and eating properties. The baking properties of radiation at several values of λ_p in the range 1·2–3·4 μm were studied using a hard sweet (Rich Tea) dough. At values of λ_p above 1·6 μm the baking time for satisfactory product moisture content increased and the products obtained were of poor quality and appearance.Rich Tea biscuits baked by NIR at λ_p of 1·2 μm showed no evidence of ‘checking’ (spontaneous breakage) on storage even at moisture contents which would be expected to produce 100% checking in conventionally baked products. This phenomenon could be associated with the smaller difference in moisture content between biscuit centre and biscuit rim in freshly NIR-baked biscuits compared with conventionally baked products.     

Effect of emulsifiers,fat level and type on the rheological characteristics of biscuit dough and quality of biscuits

The effect of level and type of fat as well as emulsifiers on the rheological characteristics of biscuit dough and quality of biscuits has been studied. Increasing the level of fat from 150 to 250 g kg⁻¹ softened the dough, as indicated by a reduction in extrusion time from 108 to 18 s and an increase in compliance from 31.9 to 49.9%, while it reduced the development of gluten, as shown by a reduction in elastic recovery from 0.485 to 0.365 mm. Among the different types of fats used, hydrogenated fat produced the stiffest dough. Addition of any of the emulsifiers glycerol monostearate, lecithin or sodium stearoyl lactylate lowered the elastic recovery value, indicating their contribution to the shortening effect on gluten, and also resulted in a reduction in consistency and hardness and made the dough more cohesive. The maximum change was observed with sodium stearoyl lactylate. The density, breaking strength and compression strength of biscuits decreased, indicating an improvement in crispness, with increasing fat level. The thickness of biscuits was significantly higher when hydrogenated fat or oil was used in the formulation. Biscuits made with bakery shortening had better surface characteristics and higher crispness. Glycerol monostearate and lecithin brought about a greater improvement in the quality of biscuits when compared with sodium stearoyl lactylate. Studies indicated that emulsifiers in general had a greater beneficial effect, particularly in the case of biscuits made from medium hard wheat flour. © 1999 Society of Chemical Industry     

MATHEMATICAL MODELING of TRANSIENT HEAT and MASS TRANSPORT IN A BAKING BISCUIT

Drying behavior of a single baking biscuit was modeled using unsteady state, anisotropic, two dimensional, simultaneous heat and mass balances. Solutions of these equations agreed well with the experimentally determined temperature and the moisture data. Modeling revealed that in the outer sections of the baking biscuit conduction and diffusion were the dominant heat and mass transfer mechanisms, respectively. In the central section of the biscuit the gas cells cracked with the increased vapor pressure and the upward volume expansion, then air/vapor enclaves were formed among the horizontal dough layers in the radial direction. the dominant heat and mass transfer mechanisms in the central section of the biscuit were convection. Presence of two different regime zones in a baking biscuit may have important consequences concerning the strength of the commercial products against crumbling during marketing and consumption.     

Structural and physical modifications of corn biscuits during baking process

Colour, crust browning and specific volume of batter is essential to the manufacture of biscuit of good quality, but these properties are rarely measured directly in fermenting batter due to lack of suitable instrumentation. The aim of this study was to systematically evaluate the changes in quality parameters and physical properties of corn biscuits during baking in real time and different oven temperatures using a computer vision system. Colour, crust browning and specific volume of corn biscuits were determined by an image analysis technique using a computerized vision system. Additional quality parameters evaluated were weight loss and firmness of corn biscuit samples. Baking experiments were performed at 190, 210, 230 and 250 °C under natural convection. Colour results showed that it is possible to distinguish two stages in the variation of lightness during the baking time of corn biscuit samples, independently of oven temperature. As a result of the drying effect, it was observed a weight loss and superficial dry layer formation in corn biscuit. The computer vision system can be useful to measure some quality parameters in food products because, among other advantages, it is easy to use, as well as faster and flexible.     

Dynamic rheological properties of dough as affected by amylases from various sources

The effect of alpha-amylases from cereal, fungal, and bacterial sources on dough dynamic rheological properties was investigated. Dynamic rheological study of flour-and-water doughs during resting period showed significant changes in dough rheological properties as a function of alpha-amylases. Addition of alpha-amylases caused a time-dependent decrease in G', storage modulus. The enzyme action on starch during baking increased viscous flow properties. These changes were temperature-dependent. The thermal inactivation temperature of alpha-amylase plays an important role in modification of starch. Rheological changes in dough will alter the machinability of the dough and the quality of end products.     

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...     

Overall and Local Bread Expansion,Mechanical Properties,and Molecular Structure During Bread Baking: Effect of Emulsifying Starches

In order to determine the relationship between molecular structure of wheat bread dough, its mechanical properties, total and local bread expansion during baking and final bread quality, different methods (rheological, nuclear magnetic resonance, magnetic resonance imaging and general bread characterisation) were employed. The study was extended on wheat dough with starch modified by octenyl succinic anhydride (OSA) in order to generalise the results. The interest of investigating multi-scale changes occurring in dough at different phases of baking process by considering overall results was demonstrated. It was found that OSA starch improved the baking performance during the first phase of baking. This feature was due to a higher absorption of water by OSA starch granules occurring at temperatures below that of starch gelatinization, as confirmed by NMR, and consecutive higher resistance to deformation for OSA dough in this temperature range (20–60 °C). This was explained by a delayed collapse of cell walls in the bottom of the OSA dough. In the second phase of baking (60–80 °C), the mechanism of shrinkage reduced the volume gained by OSA dough during the first phase of baking due to higher rigidity of OSA dough and its higher resistance to deformation. MRI monitoring of the inflation during baking made it possible to distinguish the qualities and defaults coming from the addition of OSA starch as well as to suggest the possible mechanisms at the origin of such dough behaviour.     

Phenolic extracts of carrot,grape leaf and turmeric powder: antioxidant potential and application in biscuits

Natural antioxidants have gained interest for their role in preventing lipids oxidation. The goals of this investigation were to study the antioxidant potential of carrot (Daucus carota), grape (Vitis vinifera) leaf and turmeric (Curcuma longa) powder extracts and to evaluate their addition as natural antioxidants in biscuits. Physical and chemical properties of biscuit were evaluated during processing and storage. Electrophoretic properties of biscuit dough were carried out to understand the impact of different extracts on the processing of biscuits. Biscuits prepared with 1 % (w/w) grape leaves ethanol (70 %) extract (GLE), carrot aqueous extract (CE), and tumeric aqueous extract (TE) were acceptable. Among extracts, TE was found to retain only 11.2 % activity, wherein GLE had retained 51.0 % activity after baking, which was comparable to butylated hydroxyanisole and better than tert-butylhydroquinone (TBHQ). TBHQ was found to possess the highest activity, followed by GLE, TE and CE, respectively. The ash content of biscuits enriched with TE and GLE was near to that of the control sample. Addition of CE, GLE and TBHQ reduced the force required for breakage. After 15 days of storage, PV was increased in all samples, but in the case of GLE-enriched sample there was a sudden increase in PV from 0.034 to 0.374. Supportive electrophoresis study indicated that there was no change in the protein subunits of biscuit dough fro different samples. It could be concluded that GLE, CE and TE might be used in biscuit baking as natural antioxidants.     

Impact of dairy protein powders on biscuit quality

The effects of whey protein concentrate and sodium caseinate (NaCas) on a short dough biscuit formulation were investigated with respect to dough characteristics and final product quality. Dairy powders were added at levels of 5, 10 and 15% of flour weight. Addition of 5 and 10% dairy protein powders reduced dough hardness. Doughs containing 10 and 15% NaCas had significantly higher springiness and cohesiveness values compared with the values of the control (p<0.05). Addition of both protein powders increased surface brownness, indicated by an increase in L* value. Whey protein concentrate resulted in biscuit shrinkage during baking, whereas biscuits containing NaCas powders were significantly larger than the control (p<0.05). In general, biscuits containing protein powders were harder than the control and hardness increased as the level of protein powder was increased. Confocal laser microscopy showed that doughs with NaCas had an extensive protein network and NaCas appears to interact with the flour proteins.