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Barrel Temperature (barrel + temperature)
Selected AbstractsEffect of extrusion parameters on flavour retention, functional and physical properties of mixtures of starch and d -limonene encapsulated in milk proteinINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2006Sri Yuliani Summary The purpose of this research was to investigate the retention of flavour volatiles encapsulated in water-insoluble systems during high temperature,short time extrusion process. A protein precipitation method was used to produce water-insoluble capsules encapsulating limonene, and the capsules were added to the extruder feed material (cornstarch). A twin-screw extruder was used to evaluate the effect of capsule level of addition (0,5%), barrel temperature (125,145 °C) and screw speed (145,175 r.p.m.) on extruder parameters (torque, die pressure, specific mechanical energy, residence time distribution) and extrudate properties [flavour retention, texture, colour, density, expansion, water absorption index, water solubility index (WSI)]. Capsule level had a significant effect on extrusion conditions, flavour retention and extrudate physical properties. Flavour retention increased with the increase in capsule level from 0% to 2.5%, reached a maximum value at capsule level of 2.5% and decreased when the capsule level increased from 2.5% to 5%. The die pressure, torque, expansion ratio, hardness and WSI exhibited the opposite effect with the presence of capsules. [source] Effects of extrusion conditions on quality of cassava bran/cassava starch extrudatesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2003Jorge Minoru Hashimoto Summary Blends of cassava bran and cassava starch were processed in a single-screw extruder. Response surface methodology was used to determine the effect of the concentration of cassava bran (10,50%), barrel temperature (150,210 °C), feed moisture (16,20%) and screw speed (120,180 r.p.m.) on the characteristics of the dried extrudates. All the independent variables were significant (P < 0.05) for radial expansion. The water absorption index (WAI) and water solubility index (WSI) were affected by bran level, screw speed and temperature, while only moisture and temperature influenced specific volume. The maximum radial expansion was found when all the independent variables were at their lowest levels. Lowest-density extrudates (highest specific volume) were obtained at 16,18% moisture and 180,200 °C. An increase in bran level increased the WAI but decreased the WSI when the temperature was higher than 170 °C . Screw speed had a slight effect on those responses, decreasing water absorption and increasing water solubility when changed from 120 to 180 r.p.m. [source] Mixing immiscible blends in an intermeshing counter-rotating twin screw extruderADVANCES IN POLYMER TECHNOLOGY, Issue 2 2006Ramesh Potluri Abstract Domain size of 10% dispersed polystyrene in polyethylene was followed in a 34-mm intermeshing counter-rotating twin screw extruder. Variables studied included the effects of barrel temperature, screw speed, viscosity ratio of dispersed-to-continuous phase, and parallel melt versus preblended solids feeds. After steady state was achieved, die samples were quenched for later photomicrographing. The extruder was then stopped and quenched, with subsequent pulling of the screws. From 7 to 12 additional samples were taken along the 18/1 L/D extruder for determination of the mechanism of dispersion and dispersed phase domain size by optical microscopy. At low temperatures, the polystyrene tended to fracture with sharp edges. The fine particles formed in the initial breakup underwent no further size reduction. At higher temperatures, fractured segments had rounder edges, but the size of the small domains remained constant throughout the axial length. There was some evidence of flocculation and coalescence prior to exit through the die. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25: 81,89, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20065 [source] EFFECTS OF EXTRUSION CONDITIONS ON PHYSICOCHEMICAL PROPERTIES OF A MUTANT RICE CULTIVAR, GOAMI2 , HIGH IN NONDIGESTIBLE CARBOHYDRATESJOURNAL OF FOOD QUALITY, Issue 5 2008I. CHOI ABSTRACT A mutant rice Goami2, a cultivar high in nondigestible carbohydrates (NDCs), was extrusion-cooked at feed moisture (20, 25%), screw speed (200, 300 rpm) and barrel temperature (110, 120 and 130C). Effects of extrusion conditions on the physical and functional properties were investigated. NDCs were determined by total dietary fiber (TDF) and resistant starch (RS) contents. Increasing moisture resulted in an increment of density, water absorption index (WAI) and hardness, and a decrement in expansion and water solubility index (WSI). A higher barrel temperature decreased the hardness and increased the WSI probably due to a higher proportion of gelatinized starch. Extrusion caused a reduction in TDF in the extrudates, as well as a significant decrease in RS contents. However, extrudates processed at moisture (%), screw speed (rpm) and barrel temperature (C) combinations of 25/200/110 and 25/200/120 showed no significant difference in TDF contents compared with its raw rice. Multiple regression models showed that feed moisture had the most pronounced effect on extrudate qualities, followed by barrel temperature and screw speed. PRACTICAL APPLICATIONS Rice, being one of the primary dietary sources of carbohydrates worldwide, is the major energy and nutritional sources. In recent years, demands have been increasing for rice with a wide range of value-added properties, such as enhanced nutrient, aroma, color and rice kernel shape, including functional properties. Goami2 is a mutant rice of Ilpumbyeo, a high japonica rice cultivar, and has been revealed to have higher nondigestible fractions. However, Goami2 rice has unsuitable properties for traditional cooking because of the difficulty of gelatinization, which might result in a hard texture of cooked rice compared with that of ordinary rice. On the basis of its nutritional and functional benefits, exploiting the possible utilization of Goami2 for processed food products would increase the potential consumption of Goami2 for various food products. [source] Reduction of Aflatoxins by Extrusion-Cooking of Rice MealJOURNAL OF FOOD SCIENCE, Issue 7 2006Miren Castells ABSTRACT:, The objective of this work was to determine the reduction of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2) as a function of initial moisture content of samples (24%, 27%, and 30%), barrel temperature (140, 170, and 200 °C), and residence time (30 to 70 s) when artificially contaminated rice meal was extrusion-cooked. Extruded and unextruded samples were analyzed by high-performance liquid chromatography (HPLC). Extrusion-cooking was observed to reduce aflatoxin (AF) content, which ranged from 51% to 95% depending on the type of AF and the studied variables. Only in the case of AFG2 was it found that the higher the temperature, the higher the moisture content, and the longer the residence time, the greater the reduction. Moisture content had a significant influence on reducing AFB2, AFG1, and AFG2 whereas it was not a significant factor affecting the levels of AFB1. Regardless of the type of AF, the lowest reductions were achieved at a temperature of 140 °C. Even though theoretically greater losses would be expected at highest temperature, AFB1 and AFB2 were more reduced by 170 °C than by 200 °C while AFG1 reductions were not statistically different when processing at 170 °C and 200 °C. The decrease of AF followed 1st-order kinetics; the fastest treatment in reducing AF was that at 200 °C when samples containing AFG2 were wetted to 24% and when samples containing AFB1, AFB2, and AFG1 were hydrated to 27%. By contrast, the slowest treatments were observed at a barrel temperature of 140 °C. [source] A Review on Residence Time Distribution (RTD) in Food Extruders and Study on the Potential of Neural Networks in RTD ModelingJOURNAL OF FOOD SCIENCE, Issue 6 2002G. Ganjyal ABSTRACT: Residence time distribution and mean residence time depend on process variables, namely feed rate, screw speed, feed moisture content, barrel temperature, die temperature and die diameter. Flow in an extruder has been modeled by simulating residence time distribution, assuming the extruder to be a series of continuous-stirred-tank or plug-flow reactors. Others have developed relationships for mean residence time as functions of process variables. Better models can be developed using neural networks. As an example, data from the literature were used to model mean residence time as a function of process variables using statistical regression and neural networks. Neural network models performed better than regression models. [source] PHYSICOCHEMICAL PROPERTIES OF TEXTURIZED MEAT ANALOG MADE FROM PEANUT FLOUR AND SOY PROTEIN ISOLATE WITH A SINGLE-SCREW EXTRUDER ,JOURNAL OF TEXTURE STUDIES, Issue 4 2004E.L. PARMER JR. ABSTRACT The objective of this study was to establish conditions for the texturization of soy protein isolate and peanut flour mixture using a single-screw extruder. The effects of feed moisture, screw-speed, and barrel temperature on the characteristics of the texturized products were studied. Feed moisture was the most important factor affecting the texture. Feeding ingredients with 22% moisture had the highest water absorption and expansion indices, and Hunter L value (P < 0.05). When the screw speed was above 180 RPM, the meat analog had a 12% decrease in the expansion index and a 5% decrease in moisture content (P < 0.05). When the barrel temperature was increased to 165C, there was a 12% decrease in the water absorption index, and a 23% decrease in the expansion index of the meat analogs (P < 0.05). Overall, an acceptable meat analog could be successfully produced with 22% moisture in the raw ingredient, screw speed at 140 RPM, and barrel temperatures at 150, 155, and 160C for the three temperature zones respectively. [source] Free Radical Grafting of Polyethylene with Vinyl Monomers by Reactive ExtrusionMACROMOLECULAR THEORY AND SIMULATIONS, Issue 9 2007Guofang Zhang Abstract The free radical grafting of polyethylene with vinyl monomers by reactive extrusion was studied numerically. Numerical computation expressions of key variables, such as the concentrations of the initiator and polymer, grafting degree, average molecular weight and apparent viscosity, were deduced. The evolutions of the above variables were predicted by means of an uncoupled semi-implicit iterative algorithm. The monomer conversion monotonically increases with decreasing throughput or increasing initial initiator concentration; with increasing barrel temperature, the monomer conversion first increases then decreases. The simulated results are nearly in good agreement with the experimental results. [source] Application of ultrasound and neural networks in the determination of filler dispersion during polymer extrusion processesPOLYMER ENGINEERING & SCIENCE, Issue 6 2005Zhigang Sun Mineral filler dispersion is important information for the production of mineral-charged polymers. In order to achieve timely control of product quality, a technique capable of providing real-time information on filler dispersion is highly desirable. In this work, ultrasound, temperature, and pressure sensors as well as an amperemeter of the extruder motor drive were used to monitor the extrusion of mineral-filled polymers under various experimental conditions in terms of filler type, filler concentration, feeding rate, screw rotation speed, and barrel temperature. Then, neural network relationships were established among the filler dispersion index and three categories of variables, namely, control variables of the extruder, extruder-dependent measured variables, and extruder-independent measured variables (based on ultrasonic measurement). Of the three categories of variables, the process control variables and extruder-independent ultrasonically measured variables performed best in inferring the dispersion index through a neural network model. While the neural network model based on control variables could help determine the optimal experimental conditions to achieve a dispersion index, the extruder-independent network model based on ultrasonic measurement is suitable for in-line measurement of the quality of dispersion. This study has demonstrated the feasibility of using ultrasound and neural networks for in-line monitoring of dispersion during extrusion processes of mineral-charged polymers. POLYM. ENG. SCI., 45:764,772, 2005. © 2005 Society of Plastics Engineers [source] Carboxyl terminated polyamide 12 chain extension by reactive extrusion using a dioxazoline coupling agent.POLYMER ENGINEERING & SCIENCE, Issue 12 2002Part II: Effects of extrusion conditions Condensation reactions between a carboxyl terminated polyamide 12 and a dioxazoline carried out by reactive extrusion have been characterized in the first part of this study. In the present paper, we focus on the influence of extrusion conditions on reaction progress. Influences of screw profile, screw speed, barrel temperature and feed rate have been established. The use of a flow computation software permitted confirmation of the importance of thermal and mechanical degradations in the condensation process. [source] Kinetics of Lysine and Other Amino Acids Loss During Extrusion Cooking of Maize GritsJOURNAL OF FOOD SCIENCE, Issue 2 2003S. Ilo ABSTRACT: Maize grits were extrusion-cooked in a conical, counter-rotating twin-screw extruder at different barrel temperatures, feed moistures, and screw speeds. Residence time distribution was measured by a dye tracer technique. Experiments with lysine-fortified maize grits showed a 1st order reaction for lysine loss. A detailed kinetic study has been performed for the losses during extrusion cooking of lysine, cystine, and arginine. The 1st-order rate constants were dependent mainly on product temperature and feed moisture, whereas screw speed had no influence. Activation energy of lysine, arginine, and cystine loss was 127, 68, and 76 kJ/mol, respectively. Shear stress significantly affected the rate constants of amino acids loss in extrusion cooking. [source] PHYSICOCHEMICAL PROPERTIES OF TEXTURIZED MEAT ANALOG MADE FROM PEANUT FLOUR AND SOY PROTEIN ISOLATE WITH A SINGLE-SCREW EXTRUDER ,JOURNAL OF TEXTURE STUDIES, Issue 4 2004E.L. PARMER JR. ABSTRACT The objective of this study was to establish conditions for the texturization of soy protein isolate and peanut flour mixture using a single-screw extruder. The effects of feed moisture, screw-speed, and barrel temperature on the characteristics of the texturized products were studied. Feed moisture was the most important factor affecting the texture. Feeding ingredients with 22% moisture had the highest water absorption and expansion indices, and Hunter L value (P < 0.05). When the screw speed was above 180 RPM, the meat analog had a 12% decrease in the expansion index and a 5% decrease in moisture content (P < 0.05). When the barrel temperature was increased to 165C, there was a 12% decrease in the water absorption index, and a 23% decrease in the expansion index of the meat analogs (P < 0.05). Overall, an acceptable meat analog could be successfully produced with 22% moisture in the raw ingredient, screw speed at 140 RPM, and barrel temperatures at 150, 155, and 160C for the three temperature zones respectively. [source] | |||||||||||||