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1.
Buckwheat grit cakes were prepared with a rice cake machine using the following independent variables: tempering moisture contents (15, 17, and 19%, wb), heating temperatures (240, 246, 252, and 258 degrees C), and heating times (5, 6, 7, and 8 s). Higher moisture, higher heating temperature, or longer heating time produced cakes with a higher cake specific volume. Cakes became lighter in color at a lower heating temperature or a shorter heating time. The hardest cake was produced at 252 degrees C for 5 s at 19% moisture content. The percent weight loss after tumbling decreased with increasing heating times and heating temperatures. Increased heating time resulted in more expanded products. The average rutin content decreased as the heating temperature or heating time increased. These results suggest that processing conditions, including tempering moisture, heating temperature, and heating time, significantly influenced physical and chemical qualities of buckwheat grit cakes such as specific volume, hardness, integrity, color, internal structure, and rutin content. 相似文献
2.
Extruded pellets were prepared from normal corn starch using a corotating twin‐screw extruder (25:1 L/D ratio, 31 mm diameter screw), and then expanded by heating in a conventional microwave oven for 70 sec. The effects of gelatinization level and moisture content of the extruded pellets on the morphology and physical properties of the microwave‐expanded products such as puffing efficiency, expansion bulk volume, and bulk density were investigated. The expanded shape and air cell structure differed according to the degree of gelatinization of the pellets. Maximum puffing efficiency and expansion volume with the pellets containing 11% moisture were achieved at 52% gelatinization. For this level of gelatinization, starch was extruded at 90°C barrel temperature. In addition, the moisture content of the pellets critically affected the expansion behavior. The maximum puffing efficiency and expansion volume were achieved in a moisture range of 10~13%. For optimum product shape and uniform air cell distribution, the pellets should undergo sudden release of the superheated vapor during the microwave‐heating. The expansion by microwave‐heating was optimized at ≈50% gelatinization. 相似文献
3.
The microwave expansion of glassy, unexpanded amylopectin pellets was studied. Amylopectin was extruded at three levels of specific mechanical energy (483, 809, and 846 kJ/kg), and 35–40% moisture content, without expansion at the die. Glassy pellets were obtained by drying and equilibrating the extrudates at five water activities (aw 0, 0.11, 0.33, 0.67, and 0.75). The pellets were characterized by measuring volume, porosity, and moisture content. The pellets were then expanded in a constant power microwave oven to determine the degree of expansion. When subjected to microwave heating, regardless of extrusion condition and initial aw, the pellets expanded from the center where the highest temperature was recorded and then expansion advanced in the whole volume. Maximum expansion was reached after 30 sec of heating, after which samples started to burn from the center. Samples simultaneously expanded and lost moisture, both processes being faster and more intense for pellets of higher initial aw. No expansion was observed for the pellets stored at aw 0, while collapse was observed for pellets stored at aw 0.73. A linear correlation between pellet expansion temperature and glass transition temperature was obtained. A hypothesis for the microwave expansion of glassy extrudates was formulated and represented on a state diagram. 相似文献
4.
E. Aguilar‐Palazuelos J. de J. Zazueta‐Morales F. Martínez‐Bustos 《Cereal Chemistry》2006,83(4):363-369
The aim of this work was to study the effects of extrusion barrel temperature (75–140°C) and feed moisture (16–30%) on the production of third‐generation snacks expanded by microwave heating. A blend of potato starch (50%), quality protein maize (QPM) (35%), and soybean meal (SM) (15%) was used in the preparation of the snacks. A laboratory single extruder with a 1.5 × 20.0 × 100 mm die‐nozzle and a central composite routable experimental design were used. Expansion index (EI) and bulk density (BD) were measured in expanded pellets, viscosity at 83°C (V83), thermal properties, and relative crystallinity were measured in extruded pellets. EI increased and BD decreased when the barrel temperature was increased, while the feed moisture effect was not significant. V83 increased when feed moisture increased. Extrusion modified the crystalline structures of the pellets and the X‐ray data suggests the formation of new structures, probably due to the development of amylose‐lipid complexes. The maximum expansion of pellets was found at barrel temperatures of 123–140°C, and feed moisture of 24.5–30%. It is possible to obtain a functional third‐generation snack with good expansion characteristics using a microwave oven, and this snack has health benefits due to the addition of QPM and SM. 相似文献
5.
Oatrim (oat β‐glucan amylodextrins) was evaluated as a fat substitute in a cake system. The physical and rheological properties of cakes containing shortening replaced with 20, 40, and 60% by weight of Oatrim were characterized. The increase in the specific gravity of the cakes and the decrease in the viscosity as more shortening was replaced with Oatrim were correlated with the change in the cake volume. The number of air bubbles present in the cake batters varied significantly; however, the size of the observed bubbles did not change. The cakes containing more Oatrim displayed a higher starch gelatinization temperature due to the amylodextrins in the Oatrim. The dynamic rheological properties of the cakes were investigated during baking and correlated with the differential scanning calorimetry results. The oscillatory shear storage moduli decreased upon initial heating, then increased due to starch gelatinization, and finally reached a plateau value that varied based on the sample composition. Moreover, increased replacement of shortening with Oatrim resulted in higher observed oscillatory shear storage moduli. The cakes prepared with up to 20% by weight of Oatrim did not evidence significant changes in softness (P < 0.01) and generally exhibited similar physical properties to the control cake. 相似文献
6.
A process was described for creating puffed wheat starch based or hybrid starch and rice snack foods processed in a rice cake puffing machine. Puffed cakes consisting of wheat starch and whole grain brown rice, created by mixing wheat starch beads with brown rice before processing and puffing for 10 sec (cooking time) at 210°C, exhibited greater flexibility and fracture strength than traditional rice cakes. The density of puffed wheat starch cakes decreased with increasing moisture content independent of particle size for particles 0.8–5 mm in diameter. The addition of sucrose and shortening promoted the formation of lower density puffed cakes at lower moistures, while salt had little effect. 相似文献
7.
Isabela Bastos-Cardoso José de J. Zazueta-Morales Fernando Martínez-Bustos Yoon Kil-Chang 《Cereal Chemistry》2007,84(2):137-144
In various Latin American countries, large volumes of potato are classified as unsuitable for use as food and destined for use as feed. This raw material has a high starch and fiber content that could be used in the production of different kinds of food. The objective of this research was the preparation and characterization of extruded whole potato pellets expanded by microwave heating. A 33 central composite routable experimental design and response surface methodology were used. The barrel temperature (BT, 93–127°C), feed moisture (FM, 19–29%), and corn starch concentration (CS, 3–37%) in the blends were evaluated. CS was the most important variable affecting the functional properties of the expanded pellets. Adding CS to the blends increased the expansion index and viscosity and improved luminosity, decreasing the apparent density and breaking force of the products. Low BT and especially high FM increased the luminosity of the expanded pellets. Increasing FM content increased the viscosity of the expanded pellets. The best functional characteristics for the expanded pellets were obtained using a blend of 63% potato flour and 37% CS, extruded at 110°C BT with 24% FM content. Nonfood-grade whole potato flour showed good potential for use in the production of expanded pellets with acceptable functional properties. 相似文献
8.
9.
This study was conducted to develop a ready‐to‐eat extruded food using a single‐screw laboratory extruder. Blends of Indian barley and rice were used as the ingredients for extrusion. The effect of extrusion variables and barley‐to‐rice ratio on properties like expansion ratio, bulk density, water absorption index, hardness, β‐glucan, L*, a*, b* values, and pasting characteristics of extruded products were studied. A central composite rotatable design was used to evaluate the effects of operating variables: die temperature (150–200°C), initial feed moisture content (20–40%), screw speed (90–110 rpm), and barley flour (10–30%) on properties like expansion ratio, bulk density, water absorption index (WAI), hardness, β‐glucan, L*, a*, b* values, and sensory and pasting characteristics of extruded products. Die temperature >175°C and feed moisture <30% resulted in a steep increase in expansion ratio and a decrease in bulk density. Barley flour content of 10% and feed moisture content of <20% resulted in an increased hardness value. When barley flour content was 30–40% and feed moisture content was <20%, a steep increase in the WAI was noticed. Viscosity values of extruded products were far less than those of corresponding unprocessed counterparts as evaluated. Rapid visco analysis indicated that the extruded blend starches were partially pregelatinized as a result of the extrusion process. Sensory scores indicated that barley flour content at 20%, feed moisture content at 30%, and die temperature at 175°C resulted in an acceptable product. The prepared product was roasted in oil using a particular spice mix and its sensory and nutritional properties were studied. 相似文献
10.
Corn distillers dried grains (DDGS) were compacted into cylindrical pellets (3.5 cm in length, 1.5 cm in diameter) utilizing a closed‐end die under axial stress from a vertical piston applied by an Instron universal testing machine. The effects of independent variables, including the raw material moisture content (25–35% db), processing temperature (100–120°C), pressure (12.5–37.5 MPa), and dwell time (5–15 sec) on pellet density, durability, and stability were determined using response surface methodology. Moisture content, temperature, and pressure significantly affected (P < 0.05) the properties of DDGS pellets, while the influence of dwell time was negligible (P > 0.05). Increasing temperature initially increased and then decreased unit density. High moisture and pressure had favorable effects on unit density and durability rating. The density ratio increased with increasing pressure and moisture content. The results suggested technical feasibility of compacting DDGS. For the range of variables tested, optimum levels were identified as 34.6% moisture content, 107°C press temperature, and 36.8 MPa pressure to obtain maximum durability and density and acceptable dimensional stability. 相似文献
11.
Sponge cakes were formulated using isomaltooligosaccharide (IMO) syrup as a sweetener to replace 0, 25, 50, 75, and 100% sucrose. The qualities of cakes were evaluated by physicochemical, microbiological, and sensory evaluation analyses. The viscosity in cake batter, cake volume, crumb Hunter a value, and IMO contents of baked cakes increased with increasing IMO syrup level, whereas the specific gravity in cake batter, crust L a b, and crumb L and b values, and hardness of baked cakes showed a reverse trend. The crust and crumb of cakes became darker and less yellow and had a better tender and less sweet texture as IMO syrup level increased and sucrose decreased. The degree of overall liking of cakes increased with increasing IMO syrup level. Total plate counts exceeded 105 CFU/g for cakes stored at 25°C for three days and <103 CFU/g for the samples stored at 5°C for seven days. The changes in the moisture content, water activity, L a b values, and IMO contents of samples did not differ during storage. Overall, sucrose in the formulation of sponge cakes could be partially or fully replaced with IMO syrup. 相似文献
12.
Shortening in a conventional yellow layer cake was replaced by maltodextrin (MD), amylodextrin (AD), octenyl succinylated amylodextrin (OSAD), or mixtures (MD+AD and MD+OSAD). The physical and sensory characteristics of the shortening‐free cakes were investigated. The specific gravity and viscosity of the cake batter, and the volume index of the baked cake were significantly reduced by MD, whereas the cake with added AD or OSAD showed a higher volume index than the control cake containing the shortening. An equivalent mixture of MD and AD, or MD and OSAD, however, produced cakes with a volume index and color defined as ΔE*(ab) that was similar to the control cake. Sensory evaluation revealed that the cakes containing AD or OSAD had significantly higher firmness than the control, but the cakes containing a mixture of MD and AD had firmness, springiness, and overall flavor scores similar to that of the control cake. According to instrumental texture profile analysis (TPA), MD addition, either alone or mixed with AD or OSAD, reduced firmness, whereas AD addition made the cake significantly firmer. When the shortening‐free cakes were stored for eight days at 4°C, TPA revealed greater changes in cake firmness and adhesiveness for MD alone. Cakes made from mixtures of dextrins (MD+AD and MD+OSAD) showed textural change with storage similar to that of the control cake, although the MD+AD cake remained softer than the control. 相似文献
13.
Starch and protein separated from oat were chemically modified using cross‐linking and acetylation protocols for starch, and deamidation and succinylation for protein isolate. Cross‐linking decreased swelling power of starch, whereas syneresis increased, but cross‐linking does not have a significant effect on gelatinization temperature. Acetylation increased swelling power, but gelatinization temperature and syneresis diminished. Deamidation and succinylation increased nitrogen solubility index, emulsion activity, foaming capacity, and water and oil binding capacity. Emulsion stability did not change with deamidation and it diminished with succinylation, while foaming stability decreased with both treatments. Acetylated starch and two types of modified proteins were substituted for 5, 10, 15, and 20% of oat flour to bake cake samples and then physical properties of the cakes were measured. Acetylated starch increased batter viscosity, cake volume, and whiteness of cake crust. Increased level of deamidated protein produced cakes with lower batter viscosity, higher volume, and darker color (increase in redness). Application of higher levels of succinylated protein led to higher batter viscosity and lightness, and lower cake volume. Therefore, substitution of deamidated protein and acetylated starch can improve cake properties. 相似文献
14.
Corn masa by‐product streams are high in fiber and are amenable for utilization in livestock feed rations. This approach is a potentially viable alternative to landfilling, the traditional disposal method for these processing residues. Suspended solids were separated from a masa processing waste stream, blended with soybean meal at four levels (0, 10, 20, and 30% wb), and extruded in a laboratory‐scale extruder at speeds of 50 rpm (5.24 rad/sec) and 100 rpm (10.47 rad/sec) with temperature profiles of 80‐90‐100°C and 100‐110‐120°C. Processing conditions, including dough and die temperatures, drive torque, specific mechanical energy consumption, product and feed material throughput rates, dough apparent viscosity, and dough density, were monitored during extrusion. The resulting products were subjected to physical and nutritional characterization to determine the effects of processing conditions for these blends. Extrudate analysis included moisture content, water activity, crude protein, in vitro protein digestibility, crude fat, ash, product diameter, expansion ratios, unit and true density, color, water absorption and solubility, and durability. All blends were suitable for extrusion at the processing conditions used. Blend ratio had little effect on either processing parameters or extrudate properties; extrusion temperature and screw speed, on the other hand, significantly affected both processing and product properties. 相似文献
15.
Relationships among soft wheat quality parameters relating to sponge cake volume and sensory tenderness were investigated. Sixteen soft wheats from the 2008–2009 crop and 11 from the 2009–2010 crop, including Japanese soft wheat cultivars, advanced breeders' lines, and western white wheat imported from the United States, were milled and evaluated for protein content, sucrose solvent retention capacity value, specific surface area, flour pasting properties, batter pasting viscosity, sodium dodecyl sulfate sedimentation (SDSS) volume, farinograph properties, specific cake volume, and sensory tenderness score to investigate their relationships. Batter pasting viscosity was measured with a Rapid Visco Analyzer (RVA) at 2 min after reaching 90°C in heating a mixture with equal weights of flour, sucrose, and water. RVA minimum viscosity of flour suspension in water was the most influencing factor and positively correlated to specific cake volume, and RVA batter pasting viscosity and SDSS volume were negatively correlated. Meanwhile, protein content and SDSS volume were strongly negatively correlated with sensory tenderness score. Stepwise multiple regression analysis selected protein content and specific cake volume as independent variables to predict sensory tenderness score; however, SDSS volume and farinograph properties relating to protein strength were not selected. Protein content affected sponge cake tenderness independently of specific cake volume, which was related to differences in cake density. 相似文献
16.
Cake shortening contents were replaced with Nutrim oat bran (OB) and flaxseed powder, and the effects of these substitutions on the physical and rheological properties of cakes were investigated. Cakes with shortening replaced up to 40% by weight possessed a volume similar to that of the control cake produced with shortening. Replacement using Nutrim OB and flaxseed powder revealed significant color changes in both the cake crust and crumb. At high levels of substitution, the cake crust became lighter, while the crumb darkened. At >40% by weight substitution with either Nutrim OB or flaxseed, the cakes displayed increased hardness; however, cohesiveness and springiness increased gradually with increasing substitution. Increased substitution with Nutrim OB caused an increase in the measured shear viscosity and oscillatory storage and loss moduli of the cakes. Increased substitution with flaxseed caused decreases in these rheological parameters. Additional rheological experiments were performed to elucidate changes in the formulations during the baking process and indicated an increase in the elasticity of the baked batter with decreasing shortening. 相似文献
17.
A new oat hydrocolloid containing 20% β‐glucan, called C‐trim20, was obtained from oat bran concentrate through steam jet‐cooking and fractionations. The rheological characterization of the C‐trim20 was conducted using steady and dynamic shear measurements. The C‐trim20 suspension exhibited a shear‐thinning behavior that was more pronounced at high shear rates and high concentrations. Its dynamic viscoelastic moduli increased with increasing concentration while the frequency at which G′ and G″ crossover decreased. The C‐trim20 suspension at various concentrations followed the Cox‐Merz rule. C‐trim20 was also evaluated for potential use in baked products, specifically cakes. The baking performance of C‐trim20 was tested by incorporating it into cake formulations. The inclusion of this hydrocolloid gave increased elastic properties to cake batters and produced cakes containing 1 g of β‐glucan per serving with volume and textural properties similar to those of the control cake. 相似文献
18.
A series of cross‐linked hydroxypropylated corn starches were extruded with a Leistritz micro‐18 co‐rotating extruder. Extrusion process variables including moisture (30, 35, and 40%), barrel temperature (60, 80, and 100°C), and screw design (low, medium, and high shear) were investigated. Scanning electron microscopy (SEM) of extruded starches showed a gel phase with distorted granules and granule fragments after extrusion at 60°C. After extrusion at 100°C only a gel phase was observed with no granular structures remaining. High performance size exclusion chromatography (HPSEC) equipped with multiangle laser light‐scattering (MALLS) and refractive index (RI) detectors showed extruded starches degraded to different extents, depending on extrusion conditions. The average molecular weight of the amylopectin of unextruded native corn starch was 7.7 × 108. Extrusion at 30% moisture, 100°C, and high shear reduced the molecular weight of amylopectin to 1.0 × 108. Hydroxypropylated normal corn starch extruded at identical conditions showed greater decreases in amylopectin molecular weight. With the addition of cross‐linking, the amylopectin fractions of the extruded starches were less degraded than those of their native and hydroxypropylated corn starch counterparts. Similarly, increasing moisture content during extrusion lowered amylopectin degradation in the extruded starches. Increasing temperature during extrusion of cross‐linked hydroxypropylated starches at high moisture content (e.g., 40%) lowered amylopectin molecular weights of the extruded starches, whereas increasing extrusion temperature at low moisture content (30%) resulted in less degraded molecules. This difference was attributed to the higher glass transition temperatures of the cross‐linked starches. 相似文献
19.
Nehru Chevanan Kurt A. Rosentrater Kasiviswanathan Muthukumarappan 《Cereal Chemistry》2008,85(2):132-139
Three isocaloric (3.5 kcal/g) ingredient blends containing 20, 30, and 40% (wb) distillers dried grains with solubles (DDGS) along with soy flour, corn flour, fish meal, and mineral and vitamin mix, with net protein adjusted to 28% (wb) for all blends, were extruded in a single‐screw laboratory‐scale extruder at screw speeds of 100, 130, and 160 rpm, and 15, 20, and 25% (wb) moisture content. Increasing DDGS content from 20 to 40% resulted in a 37.1, 3.1, and 8.4% decrease in extrudate durability, specific gravity, and porosity, respectively, but a 7.5% increase in bulk density. Increasing screw speed from 100 to 160 rpm resulted in a 20.3 and 8.8% increase in durability and porosity, respectively, but a 12.9% decrease in bulk density. On the other hand, increasing the moisture content from 15 to 25% (wb) resulted in a 28.2% increase in durability, but an 8.3 and 8.5% decrease in specific gravity and porosity, respectively. Furthermore, increasing the screw speed and moisture content of the blends, respectively, resulted in an increase of 29.9 and 16.6% in extruder throughput. The extrudates containing 40% DDGS had 8.7% lower brightness, as well as 20.9 and 16.9% higher redness and yellowness, compared with the extrudates containing only 20% DDGS. Increasing the DDGS content from 20 to 40% resulted in a 52.9 and 51.4% increase in fiber and fat content, respectively, and a 7.2% decrease in nitrogen free extract. As demonstrated in this study, ingredient moisture content and screw speed are critical considerations when producing extrudates with ingredient blends containing DDGS, as they are with any other ingredients. 相似文献
20.
Corn distillers' dried grains with solubles (DDGS) was extruded with corn meal in a pilot plant single‐screw extruder at different extruder die temperatures (100, 120, and 150°C), levels of DDGS (0, 10, 20, and 30%) and initial moisture contents (11, 15, and 20% wb). In general, there was a decrease in water absorption index (WAI), water solubility index (WSI), radial expansion, and L* value with an increase in DDGS level, whereas a* value and bulk density increased. Increase in extruder die temperature resulted in an increase in WSI and WAI but a decrease in L* and bulk density. Peak load was highest at 30% DDGS as compared with 0, 10, and 20% DDGS extrudates. Die temperature of 120°C and initial moisture content of 20% resulted in least peak load. The a* value remained unaffected by changes in extruder die temperature. Radial expansion was highest at extruder die temperature of 120°C. Maximum WAI, WSI, radial expansion, and L* value were obtained at 15% initial moisture content. An increase in initial moisture content, in general, decreased L* value and bulk density but increased a* value of extrudates. 相似文献