bluuebunny/crossref_metadata_2025 huggingface dataset:
CENTERPOINT NUTRIENT DEGRADATION IN HEAT PROCESSED CONDUCTION HEATING FOOD MODEL
Authors: RAMASWAMY H. S. , GHAZALA S.
Published: February 2007

A methodology was developed for the evaluation of centerpoint nutrient degradation in conduction heating canned food subjected to thermal processing. the methodology involved sealing of 75μL aliquote of test solution in a leakproof pressure‐stable stainless steel capsule, placing the capsule at the geometric center of a can filled with a conduction heating simulated food prior to the closure, and recovering the capsule and analyzing the contents following a given thermal treatment. Experiments carried out using aqueous solutions of ascorbic acid and thiamine indicated good reproducibility of the results. Employing kinetic data for thermal destruction of the nutrients and center temperature‐time history of the food simulant obtained from several simultaneously processed cans, the centerpoint nutrient retention predicted by several models agreed favorably with the experimental results.
SIMULATION of CANOLA and BARLEY DRYING IN A DEEP BED
Authors: CENKOWSKI STEFAN , MUIR WILLIAM E. , JAYAS DIOVIR S.
Published: February 2007

A mathematical model for a radial, continuous‐crossflow dryer was modified and used to simulate the drying process in a fixed bed dryer. the predictions of the adapted model were compared with experimental test results for canola drying at the following drying conditions: airflow rates of 0.4 and 0.6 kg/(m2s), inlet air humidity 0.098 and 0.0114 kg/kg of dry air, initial grain moisture content 0.221 and 0.251 kg/kg dry basis. In both tests the inlet drying air temperature was kept at an average of 67.5°C. At the end of canola drying, the mean drying air temperature predicted by our model was within 1°C of the measured temperature and the mean predicted moisture content was within 0.5% of the measured moisture content, dry basis. Also, our model was verified against experimental results for barley published by other authors and against predictions from a published model for barley. the predictions from our model were in good agreement with the published experimental and predicted data. Simulations results for canola and barley drying in the same thickness of a deep bed were compared. Simulations were conducted to investigate the effects of canola properties such as bulk density and dryinig conditions of air such as airflow rate and air humidity on drying in deep beds of canola.
MODELING the AVERAGE SHEAR RATE IN A CO‐ROTATING TWIN SCREW EXTRUDER
Authors: MOHAMED IBRAHIM O. , OFOLI ROBERT Y. , MORGAN RON G.
Published: February 2007

A procedure similar to the one commonly used with mixers has been utilized to develop a model for estimating the shear rate in co‐rotating twin screw extruders. Newtonian and non‐Newtonian fluids were used to estimate the average shear rate for three screw configurations of a Baker Perkins (MPF‐50D) twin screw extruder. As would be expected, the shear rate was highly correlated to the screw speed. At a given screw speed, 30 forwarding paddles generate the highest rate of shear, followed by feed screws and single lead screws. No data was found in the published literature to provide comparison with the results of this work. However, the model has performed well in heat transfer analysis of twin screw processes.

The procedure is sensitive to screw configuration, accounts for the shearing effects in the different regions within the extruder barrel, and covers a range of screw speeds (100–400 RPM) typical of what is encountered in industrial pilot plants. Even though much more work remains to be done before the shear rate can be confidently characterized for composite screw configurations, this technique provides a sound foundation.
FUZZY EXPERT SYSTEMS: A PROTOTYPE FOR CONTROL of CORN BREAKAGE DURING DRYING
Authors: ZHANG Q. , LITCHFIELD J. B.
Published: February 2007

A prototype fuzzy expert system was developed to predict the breakage susceptibility of corn for certain drying conditions and to provide recommendations for dryer control. the control decisions were based on predicted levels of breakage, drying conditions, and the recommendations of corn drying experts. Drying temperature, initial moisture content, equilibrium moisture content, and level of the wet product holding bin were used as the process information for providing recommendations for drying temperature and flow rate adjustment. Two example drying processes were tested. the results of the study showed that (1) the predicted corn breakage levels matched the experimental results and (2) the control recommendations by the system were consistent with domain experts.
MATHEMATICAL ANALYSIS of CRITICAL PARAMETERS IN ASEPTIC PARTICULATE PROCESSING SYSTEMS
Authors: LARKIN JOHN W.
Published: February 2007

A sensitivity analysis of a one‐dimensional heat transfer model for a heat‐hold‐cool aseptic system of food products containing particulates was completed for eighteen different design, product, and process control parameters. All of the parameters, except the direct effect of the fluid specific heat, were determined to be statistically significant in influencing the accumulated lethality of the processes. the most influential parameters were surface heat transfer coefficient in the hold tube at the fluid‐particle interface, exit temperature of the fluid from the heater, initial temperature, holding tube size, and holding tube‐U value. the process/product‐related parameters that are significant in the establishement of a process are: particle diameter, surface heat transfer coefficient in the hold tube at the fluid‐particle interface, thermal properties of the fluid and particulates, maximum heater velocity ratio, maximum hold tube velocity ratio, surface heat transfer coefficient in the heater at the fluid‐particle interface, product flow rate, and particle to fluid ratio.
ON BALL'S FORMULA METHOD FOR THERMAL PROCESS CALCULATIONS
Authors: STOFOROS NIKOLAOS G.
Published: February 2007

Discrepancies between Ball's equation and his tabulated values associated with his original formula method for thermal process calculations had initially led to arguments for the validity of the equation and finally to revised sets of tables. Here, the validity of Ball's tables (within the accuracy of graphical integration) is established. A typographical error associated with Ball's published equation was identified and the correct form is presented.
BARLEY β‐AMYLASE HYDROLYSIS of STARCH DURING TWIN SCREW EXTRUSION
Authors: KOMOLPRASERT VANEE , OFOLI ROBERT Y.
Published: February 2007

Effect of moisture content, screw rpm and β‐amylase dose on the rate of maltose production in a Baker‐Perkins twin screw food extruder has been studied. Fifteen experiments were conducted using a fixed screw configuration at a fixed mass flow rate of 15 kg/h, under isothermal conditions (t=57°C) and a pH of 5.5. Each of the three variables was found to have a significant effect (P<. 05) on maltose production. Using response surface regression analysis on the experimental data, a quadratic objective function was derived. the function was optimized, subjecting it to three explicit boundary conditions, using the adaptive complex method. the optimization process yielded a maximum maltose production of 34% at 54% moisture content, 30 rpm screw speed and 157 units of enzyme/g of starch. the extent of saccharification was about 30%.
REPARTITION of WATER IN PLANT TISSUES SUBJECTED to OSMOTIC PROCESSES
Authors: MARCOTTE MICHELE , LE MAGUER MARC
Published: February 2007

A study was conducted to investigate the osmotic behavior of potato tissue in equilibrium with an osmotic medium consisting of various solutions ranging from 5% to 60% sucrose at 40°C. At equilibrium, the total volume changes of the potato tissue with respect to the initial volume were constant for a wide range of sucrose concentration of osmotic solutions (10% to 40%). In order to explain this behavior, the analysis was transposed from the global description of the entire structure to the analysis of the behavior of the cells. It was found that the cells of the potato tissue were plasmolyzed in osmotic media from 10% to 40% sucrose, that is, the protoplast of the plant cell separates from the cell wall due to the efflux of water from the cell. the extracellular volume, which comprises the cell wall and the intercellular space, increased whereas the cellular volume, which is equivalent to the protoplast, decreased to maintain a constant total volume. When the tissue was in equilibrium with highly concentrated sucrose solution (40% to 60%), a loss of the integrity of the cells seemed to happen.

Using a typical composition of the potato tissue and the expressions relating the equilibrium water content of each phase to the chemical potential of water, the calculated volume changes were predicted in good agreement with the experimental volume changes of the lumped cellular volume of the tissue. Thus, from the thermodynamic approach, one can predict quantitatively the repartition of water in the tissue.
MATHEMATICAL MODELLING of RICE BRAN OIL EXPRESSION
Authors: SIVALA K. , RAO V. VASUDEVA , SARANGI S. , MUKHERJEE R. K. , BHOLE N. G.
Published: February 2007

The expression of liquid from a solid‐liquid matrix of oil‐bearing material is a complex process and is incompletely understood. an investigation was taken up to understand the phenomena relating to compression and consolidation of rice bran and gain an insight into the flow behavior of oil under uniaxial compression. A mathematical model based on one‐dimensional consolidation theory (Terzaghi 1943) was developed with suitable assumptions, taking into account the test‐cell geometry. the experiments were conducted with two types of parboiled rice bran; original unsieved bran and bran sieved through B.S. 30 mesh. the developed model was tested and a close agreement was found between calculated and observed values.
RECOVERY and CONCENTRATION of FLAVOR COMPOUNDS IN APPLE ESSENCE BY PERVAPORATION
Authors: ZHANG S.Q. , MATSUURA T.
Published: February 2007

Recovery and concentration of flavor compounds from an apple essence (x 500) was attempted by pervaporation using a silicone rubber (polydimethylsiloxane) membrane at room temperature. the flavor components were identified by GC‐MS method, and the ratio of concentration of the flavor compound in the permeate to that in the feed was determined for each component. It was found that pervaporation is indeed an effective measure for the above purpose. Concentration ratios above 20 were achieved for flavor components with boiling points lower than 100°C.
ROLE of CULTIVAR and PRESS AID IN PRESSING CHARACTERISTICS and JUICE YIELDS of CRUSHED GRAPES
Authors: RAO M.A. , COOLEY H.J.
Published: February 2007

The stress‐volume characteristics of crushed grape cultivars: Baco Noir, Cabernet Sauvignon, Catawba, Cayuga White, Chardonnay, Concord, Delaware, Melody, Niagara, Johannisberg Riesling, and Seyval Blanc, with and without paper and rice hulls press aids were studied in an expression cell and an Instron Universal Testing Machine. the slopes of ln stress vs volume in compression were significantly (P< 0.001) dependent on the grape cultivar. Addition of 1–3% press aid by weight decreased the magnitudes of slopes by about 11% with Seyval Blanc to about 51% with Catawba; i. e., the ease with which pressing could be performed increased with the addition of press aid. With Cabernet Sauvignon grapes, addition of press aid 0.5, 1.0, and 2.0% resulted in increase in slopes ranging between 14.7 and 24.9%. the slopes of the ln stress‐ln time during the relaxation portion of the experiment were also significantly dependent (P< 0.001) on the grape cultivar; the magnitudes of the slopes increased with the addition of 1–3% paper press aid. the juice yields were affected significantly (P< 0.001) by the addition of paper press aid, with maximum yields being obtained when 1–2% (w/w) paper press aid was added. As expected, juice yields (w/w%) were significantly dependent (P< 0.001) on grape cultivars.
BATCHING DECISIONS IN A MULTI‐STAGED FOOD MANUFACTURING PROCESS
Authors: CHUNG HONG K. , NORBACK JOHN P.
Published: February 2007

Despite advances in process control, batching is a common practice in many process industries for various economic or technological reasons. Production managers often encounter a decision to produce whole or partial batches in the face of variable production targets. Producing whole batches is managerially convenient but may be economically undesirable. Producing partial batches may be managerially and qualitatively inappropriate, but enables achieving an exact production target. Batching decisions directly impact the total volume of final products, resource requirements, and unit costs of products. A model using a penalty approach was constructed to optimize product mix and batch mix under managerial and production constraints. the degree of penalty should be determined by the nature of the industry, the type of products, and the conditions of manufacturing and market. the model was applied to a case of production planning for spaghetti sauce products, and is intended as a guide for the construction of similar models in other industries and for other situtations. In the example situation investigated optimal solutions for the batch choices were regularly more economical than those driven by whole batch policies or by partial batching to meet a production target.
EFFECTS of HIGH‐PRESSURE APPLICATION ON SUBSEQUENT ATMOSPHERIC SOAKING of CORN
Authors: GUNASEKARAN SUNDARAM
Published: February 2007

Atmospheric‐soaking tests were performed on two varieties of corn samples subjected to a pretreatment of high‐pressure soaking at 10.5, 21, and 35 MPa. Soaking tests were also conducted with samples without any pretreatment at different soaking temperatures of 20, 40, 60, and 100C. Increased duration of initial high‐pressure soaking was found to reduce the rate of moisture absorption during the subsequent atmospheric soaking. Predicted soaking times required for the samples to reach 45% moisture content increased with increase in applied pressure and with increase in the duration of high‐pressure application. Therefore, initial high‐pressure application should be limited to a low pressure level and only for a short duration. Compared with the results of the high‐temperature soaking tests, initial high‐pressure application does help to shorten the steeping time required at atmospheric conditions but not to the extent to compensate for the effect of high temperatures.
SURFACE HEAT TRANSFER COEFFICIENTS ASSOCIATED WITH HEATING of FOOD PARTICLES IN CMC SOLUTIONS
Authors: AWUAH G.B. , RAMASWAMY H.S. , SIMPSON B.K.
Published: February 2007

The fluid‐to‐particle heat transfer coefficients (hfp) associated with the heating of cylindrical specimens of potato and carrot were evaluated in carboxy‐methylcellulose (CMC) solutions (0–1%) at 50–80C. Average hfp values ranged from 80 to 450 W/m2C for potatoes and 100 to 550 W/m2C for carrots. Temperature and concentration of CMC influenced its power law parameters and hence. hfp values while fluid velocity (0.2 to 0.7 × 10−3 m/s), sample size (0.016–0.023 m diameter, 0.02–0.04 m length) and flow direction (upward and downward) had marginal effects. Natural convection dominated the flow regime, giving good correlations between Nusselt and Rayleigh numbers.
FUZZY LOGIC CONTROL FOR A CONTINUOUS CROSSFLOW GRAIN DRYER
Authors: ZHANG QIN , LITCHFIELD J. BRUCE
Published: February 2007

This paper presents the assembly and the performance of a fuzzy logic control system in regulating a laboratory continuous crossflow grain dryer. With fuzzy control, similar outlet moisture contents and lower outlet breakage susceptibility of corn were obtained as compared to the manually controlled dryer operation. the results verified that drying‐induced corn breakage could be reduced through the application of fuzzy logic control. Like the corn drying process, many food processes are difficult to control automatically with conventional control techniques due to their complex nature. Fuzzy logic control provides an attractive solution for control of those processes.
OPTIMAL DESIGN of A ROTARY CUTTER BY LAGRANGIAN MULTIPLIERS FOR the CONTINUOUS PRODUCTION of INDIAN UNLEAVENED FLAT BREAD
Authors: SRIDHAR B.S. , RAO B.V. SATHYENDRA
Published: February 2007

A mathematical approach for the optimal design of a rotary cutter by using Lagrangian Multipliers, in the continuous production of chapatis (Indian unleavened flat bread), is presented.

The objective function has been taken as the output and the constraints have been recognized as diameter and speed of rotation of the roller, number of cutters, diameter of the cutter and gap between the cutters. the numerical profile obtained from the method is in close agreement with the experimental values. It has been observed that, within the range of roller diameters and rotational speeds studied, the roller of diameter 0.165 m with three cutters was optimal with an output of 710 units h−1, leaving about 38% scrap dough for recycling.
BULK VOLUME SHRINKAGE DURING DRYING of WHEAT and CANOLA
Authors: LANG W. , SOKHANSANJ S.
Published: February 2007

The bulk volume shrinkage of canola and wheat were measured for the temperature range of 20–80C and relative humidity range of 15–90%. the volume decreased exponentially with time as seed moisture content was reduced. For canola, an oilseed, shrinkage and moisture reduction were linearly correlated with a shrinkage coefficient of about 1.0. For wheat, a starchy grain, the relationship was also linear but the coefficient was greater than 1.3. the shrinkage coefficients for both wheat and canola did not show a correlation with drying temperature but varied linearly with relative humidity of the drying air.
ABSORPTION of WATER IN LONG‐GRAIN RICE ROUGH DURING SOAKING1
Authors: LU RENFU , SIEBENMORGEN TERRY J. , ARCHER TRACY R.
Published: February 2007

Soaking tests were conducted to determine the rate of water absorption in Newbonnet long‐grain rough rice ranging from 14 to 30% initial moisture content (dry basis) at 11, 20, 30, 40, and 50C. Four rewetting models were compared, and the following model by Becker (1959) was found to best fit the experimental data, while the rice moisture content during soaking was lower than about 40% (dry basis):

M(t) = M0+Δo+α*√t

(see a list of symbols at the end of the article). the absorption rate, dM/dt, increased with temperature and decreased with initial moisture content. A regression equation was obtained to relate the parameter α to temperature and initial rice moisture content. the initial moisture gain was not significantly affected by temperature and initial rice moisture content. the average initial moisture gain over the test temperature range was 0.75 percentage points.
FLOW BEHAVIOR of COOKED MAIZE FLOUR SUSPENSIONS and APPLICABILITY of MATHEMATICAL MODELS
Authors: BHATTACHARYA SILA , BHATTACHARYA SUVENDU
Published: February 2007

The shear‐rate/shear‐stress data of cooked maize flour suspensions were obtained using a concentric cylinder viscometer in the shear rate range of 3 and 1326 s−1. the effects of concentration of maize flour (2–10%) in the cooked suspensions on yield stress, flow behavior index, consistency index and apparent viscosity, were investigated. Cooked maize flour suspensions were pseudoplastic in nature with yield stress. At flour concentrations above 6%, the experimentally determined yield stresses were lower than those calculated from different rheological models. the shear‐rate/shear‐stress data were examined using the rheological models: the power law, Bingham plastic, Casson, Costell‐Duran, Herschel‐Bulkley and Mizrahi‐Berk models. the last two models were found to provide the best fit (r ≥ 0.991, p ≥ 0.01).
MODELING of TRIGLYCERIDE DISTRIBUTION and YIELD of ANHYDROUS MILK FAT IN A CONTINUOUS SUPERCRITICAL CARBON DIOXIDE EXTRACTION SYSTEM
Authors: YU ZER‐RAN , BHASKAR AJAY R. , RIZVI SYED S.H.
Published: February 2007

A mathematical model was developed for continuous extraction of multicomponent mixture anhydrous milk fat (AMF) with supercritical carbon dioxide (SC‐CO2) as its solvent. At a constant temperature and pressure, the triglyceride mixture was separated into vapor and liquid fractions. the composition distribution (indicated by acyl carbon number), mass distribution and yield of AMF were calculated by the model based on thermodynamic equilibrium and material balance. the feed composition and distribution coefficient were required information in this model. the experimental values for the extract were in good agreement with the model used. the results for the raffinate were not as precisely modeled. the main factors which affected the model were temperature, pressure, solvent/feed ratio and extract fraction.
MOISTURE SORPTION and VOLUMETRIC CHANGES of CANOLA DURING HYDROTHERMAL PROCESSING
Authors: THAKOR N.J. , SOKHANSANJ SHAHAB , PATIL R.T. , DESHPANDE S.D.
Published: February 2007

The moisture content and volume change of canola seeds immersed in water or exposed to steam were measured. Three water temperatures of 22, 50 and 75C and one wet steam treatment (atmospheric pressure ∼ 100C) were used in the experiments. the maximum moisture attained by the canola seed was 0.67 decimal (db) in soaking and 0.54 decimal (db) in steaming. the moisture sorption rates were higher at higher temperatures of soaking. the coefficient of expansion did not vary significantly among treatments and an average coefficient of 1.032 per unit change in moisture content was obtained.
MECHANISMS INVOLVED IN the INFUSION of STARCH BASED POROUS FOOD MATERIALS BY OIL BASED LIQUID FOODS.
Authors: HIÇSASMAZ Z. , CLAYTON J.T.
Published: February 2007

Mechanisms involved in “infusion”, defined as filling in the pores of starch based solid foods with high calorie liquid foods to obtain calorically dense food products, were investigated. Parameters under investigation were the effect of: Pore structure of the solid matrix on infusion uniformity, wettability of the solid matrix on the rate of liquid uptake, viscosity (apparent viscosity for non‐Newtonian liquids) and surface tension of the infusing liquid on the rate of liquid uptake and the pressure gradient to be imposed. Infusion uniformity could not be achieved with chocolate syrup, no matter whether the porous solid matrix was highly expanded (Bread, porosity = 0.9) or relatively compact (Cookies, porosity = 0.6), due to the filtration of particulate solids. Infusion was found to be a fast, efficient process which takes place between a moderate vacuum and barometric pressure. For Newtonian oils, wettability was found to be the major mechanism of infusion.
MODELING MICROWAVE COOKING of COCKTAIL SHRIMP
Authors: MALLIKARJUNAN P. , HUNG Y.‐C. , GUNDAVARAPU S.
Published: February 2007

A mathematical model for microwave cooking of cocktail shrimp was developed. the model included heat and mass transfer and microbial inactivation kinetics. A simple 2 dimensional cylindrical slab geometry was used and model equations were solved using the finite difference method. the model predictions on temperature and mass loss were in good agreement with the observed data. Temperature predictions were within ± 6C and mass predictions were within ± 2 g of the observed data.
MODELING the VIBRATIONAL RESPONSE of PLANTAIN FRUITS
Authors: KAJUNA S.T.A.R. , BILANSKI W.K. , MITTAL G.S. , HAYWARD G.L.
Published: February 2007

Plantain fruits of the plantain subgroup (Musa AAB Group) were obtained at a green stage and used in this study. the fruits were labelled for identification, and stored in a chamber maintained at a temperature of 20C and relative humidity of 90 ± 4%. On daily basis, for a period of 14 days, the fruits were removed from the storage chamber and each was weighed to record the mass. They were vibrated vertically on a vibration exciter through a range of frequencies from 10 to 2000 Hz. the frequency response was modeled by a single‐degree‐of‐freedom Kelvin model. the mass of the fruit, the stiffness, the natural frequency and the critical damping all decreased significantly (p < 0.01) with storage time. There was no significant change (p > 0.05) in the damping coefficient of the fruit. the damping ratio decreased significantly (p < 0.01) with storage time. the models that described the changes in these parameters with storage time were obtained by stepwise regression, and are also presented. It was concluded that a single degree‐of‐freedom model provides satisfactory results of the vibrational characteristics of intact plantain fruit.
RHEOLOGICAL CHARACTERIZATION of COFFEE MUCILAGE
Authors: OLIVEROS CARLOS E. , GUNASEKARAN SUNDARAM
Published: February 2007

Rheological behavior of mucilage obtained from two varieties of coffee grown in Colombia (Caturra and Colombia) was studied as a function of ripe cherry content (RCC) and postharvest time (PHT). A Brookfleld HB DV‐III viscometer was used in concentric cylinder geometry over a shear rate range of 4.8 to 120 s−1. the power‐law model was used to describe the shear stress versus shear rate data, and the consistency index (K) and flow behavior index (n) were determined. the mucilage is a highly viscous and pseudoplastic (n < 0.3) fluid. the K increased and n decreased as the RCC and PHT increased. the mucilage of the Caturra variety was more viscous and shear thinning than that of the Colombia variety. Microstructural examination of the mucilage revealed that certain weak structures as phloem vessels found in the mucilage may be destroyed upon application of shear stress and may contribute to the pseudoplastic nature of the mucilage. Diffusion of tannin from the pulp to mucilage with delay in postharvest processing may be responsible for increased apparent viscosity with increased PHT.
ANALYSIS of EXPANDED‐FOOD TEXTURE BY IMAGE PROCESSING PART I: GEOMETRIC PROPERTIES
Authors: GAO X. , TAN J.
Published: February 2007

Color image processing techniques were developed to characterize the textural properties of expanded food products. Three major approaches were taken to extract image features from surface and cross‐section images of a test product. Scanning electronic microscopy (SEM) was employed to measure the cell size and density. Correlation and regression analyses were performed between the image features and SEM measurements. A number of image features were found highly descriptive of texture‐related geometric properties.
INFLUENCE OF TEMPERATURE AND ADDITIVES ON THE ADSORPTION KINETICS OF FOOD EMULSIFIERS
Authors: TAIWO K. , KARBSTEIN H. , SCHUBERT H.
Published: February 2007

The influence of temperature (6, 25, and 50C) and additive substances (salt, sugar and vinegar) on the adsorption kinetics of typical food emulsifiers, egg yolk and whey protein concentrate (WPC) were studied using the Wilhelmy plate/burst membrane method to monitor the interfacial tension (IT) at the water soya oil interface. The effect of solutes on the adsorption kinetics depended on emulsifier type. The presence of salt and higher temperatures reduced the IT of egg yolk solutions, while the IT of WPC solutions increased with salt addition. The presence of sugar and vinegar generally increased the IT of both emulsifiers while increased temperature caused the equilibrium IT of both emulsifiers to decrease and attain equilibrium more quickly.
THERMOPHYSICAL PROPERTIES OF FRESH AND ROASTED COFFEE POWDERS1
Authors: SINGH PREM C. , SINGH RAKESH K. , BHAMIDIPATI S. , SINGH SHYAM N. , BARONE PETE
Published: February 2007

The present work deals with experimental determination of bulk specific heat, bulk thermal conductivity, bulk and true density and moisture content of Columbian and Mexican coffee bean powders. Specific heat was determined by DSC, thermal conductivity by modified Fitch apparatus, density by stereopycnometer and moisture contents by standard vacuum oven method. Specific heat values showed marginal rise over the temperature range (45 to 150C) studied. Thermal conductivity values, determined in the temperature range of 20–60C were not found to have any definite trend with rise in moisture in the experimental range of 4.8 to 9.8% moisture (dry basis). Bulk density of powders varied appreciably (1.298 to 0.882 g.cm−3), while the change was negligible for true density (1.361 to 1.092 g.cm−3) with the degree of roasting. Statistical analysis of the data shows the reliability of the experimental determinations. Suitable correlations were developed to determine bulk specific heat and bulk density.
COMPLEX VISCOSITY‐TEMPERATURE MASTER CURVE OF CORNSTARCH DISPERSION DURING GELATINIZATION
Authors: YANG W.H. , RAO M.A.
Published: February 2007

Complex viscosity (η*) of 8% cornstarch dispersion during gelatinization at oscillatory frequencies (ω): 0.63–47.12 (rad s−1) was independent of the heating rates: 1.6–6.0 (°C min−1) when temperature was the independent variable. The influence of ω on η* was scaled by a frequency shift factor resulting in reduced complex viscosity (η*R) versus temperature (60–95C) master curve. Similar η*R master curves were derived for data on 6% and 3.5% dispersions. A modified Cox‐Merz rule correlated the complex and apparent viscosity data, and a power law model described the effect of concentration of the gelatinized structures.
MEASUREMENT OF THE HEAT TRANSFER COEFFICIENT IN A THAWING TUNNEL
Authors: GEKAS V. , CHRONAKIS I.S. , ESCADA C. , SJÖHOLM I.
Published: February 2007

In a convective (air) thawing tunnel designed in the department of Food Engineering at Lund, and previously applied for the thawing of meat, we have measured the heat transfer coefficient using an ice model with a geometry which could be approximated to an infinite slab. The heat transfer coefficient was deduced from the agreement between experimental and simulated (using a commercial numerical program) data. The results could be summarized by the following equation: Nu = 1.27Re0.553. Thus, the dependency of the heat transfer coefficient on the Reynolds number agrees well with correlations found in the literature for similar kinds (freezing, thawing) of application. In particular the found Nusselt relationship was in a very good agreement with the Heldman correlation for freezing of foodstuffs in the turbulent regime.
RHEOLOGICAL CHARACTERIZATION OF A MODEL FOOD SUSPENSION CONTAINING DISCS USING THREE DIFFERENT GEOMETRIES
Authors: MARTÍNEZ‐PADILLA L.P. , CORNEJO‐ROMERO L. , CRUZ‐CRUZ C.M. , JÁQUEZ‐HUACUJA C.C. , BARBOSA‐CÁNOVAS G.V.
Published: February 2007

The objective of this study was to characterize the flow behavior of a solid‐liquid food model which imitates Mexican sauces. The model food suspension consisted of seeds suspended in a shear‐thinning fluid (Avicel and Xanthan gum). The effects of size and particle concentration were investigated using a traditional disc geometry in wide gap (spindle), and a ribbon adapted to a rotational viscometer. The effect of particle size was evaluated in a tube viscometer. Power‐law parameters and apparent viscosity were estimated in the shear range of each viscometer. The experimental apparent viscosity showed good agreement with predictions obtained using a theoretical expression of relative viscosity for uniform spheres. In all the viscometers investigated, shear‐thinning behavior of the suspension was observed, as the aqueous phase, due to low interactions among particles. The ribbon geometry appears to be the best option for flow characterization of food suspensions containing coarse disc shaped particles.
MATHEMATICAL MODEL TO PREDICT YIELD LOSS OF MEDIUM AND LARGE TIGER SHRIMP (PENAEUS MONODON) DURING COOKING
Authors: ERDOĜDU FERRUH , BALABAN MURAT O. , CHAU KHE V.
Published: February 2007

Cooking causes moisture loss and reduces the yield of shrimp. This can be affected by its size, cooking temperature and time. A finite difference mathematical model to predict temperature distribution during heating/cooling of shrimp was modified to enable prediction of yield loss. The relationship between cooking temperature, time and yield loss was determined by isothermal experiments. For medium and large Tiger shrimp (Penaeus monodon), data were fitted into the following form: % Yield Loss = a + b*T + c *T2+ d*t2+ e*t + f*T*t where T is temperature and t is time. These equations were used in the model. Each volume element in the model was allowed to have its own yield loss; and overall yield loss was found by calculating mass average values. Experiments were conducted to cook Tiger shrimp under regular conditions and determine its yield loss, and the predictions of the model were compared with experimental data. Close agreement was obtained. This model can be used to predict yield losses during cooking of shrimp.
EFFECT OF DIFFERENT PASTEURIZATION CONDITIONS ON ENZYME INACTIVATION OF ORANGE JUICE IN PILOT‐SCALE EXPERIMENTS1
Authors: KIM HAN B. , TADINI CARMEN C. , SINGH RAKESH K.
Published: February 2007

The orange juice pasteurization is associated with enzymatic degradation (primarily pectin‐methylesterase) of soluble pectin. Time‐temperature curves were established to study different pasteurization conditions on enzyme inactivation, for fresh single‐strength orange juice from Florida, containing natural PME enzyme. The orange juice was heated in a DeLaval, model P5‐VRB plate heat exchanger with heating and cooling sections, and a 0.0101 m3 volume holding tube. The temperature in the heat exchanger was controlled by means of a pneumatic proportional controller. The residence time in the holding tube of the heat exchanger was monitored by adjusting the flow rate of the positive feed pump. The calculated holding times to obtain 90% reduction of enzyme activity ranged from 33.27 s at 80C to 17.85 s at 90C.
EFFECTS OF PECTINASE IMMOBILIZATION DURING HOLLOW FIBER ULTRAFILTRATION OF APPLE JUICE
Authors: CARRIN MARÍA E. , CECI LILIANA , LOZANO JORGE E.
Published: February 2007

The immobilization of commercial pectinases by physical adsorption on hollow fiber ultrafiltration (HFUF) membranes was studied in view of its possible application in fruit juice clarification. The optimal pH during immobilization and washing was investigated, as well as the effects of enzyme and pectin concentrations and retentate flow on the operation. Results indicated that permeate flux was not initially increased when pectin solution or apple juice was ultrafiltred through pectinase immobilized on HFUF membranes. However, enzyme immobilization greatly extended the membrane operation, by keeping permeate flux constant during prolonged periods at a reasonable yield.
DEGASSING KINETICS AND SORPTION EQUILIBRIUM OF CARBON DIOXIDE IN FRESH ROASTED AND GROUND COFFEE
Authors: SHIMONI EYAL , LABUZA THEODORE P.
Published: February 2007

Carbon dioxide produced by both the Strecker degradation reaction (Maillard reaction) and carbohydrate pyrolysis during high temperature roasting of coffee, and trapped in the fresh roasted and ground (FRG) coffee, is one of the major problems in the industry. Coffee solids can entrap or sorb up to 10 mL CO2/g. The eventual evolution of this carbon dioxide during storage after packaging in flexible films can cause the bursting of the package. A good understanding of the mechanism that governs carbon‐dioxide evolution and equilibrium in FRG coffee will provide true control over carbon dioxide release and equilibrium in the package. The objective of this study was to establish the equilibrium parameters of carbon‐dioxide sorption/desorption, and determine the rate of carbon‐dioxide diffusion from the ground coffee. Carbon dioxide sorption in FRG coffee is best described by the Langmuir isotherm. A higher degree of roasting resulted in an increase of CO2 sorption in the coffee. The degassing kinetics of CO2 from FRG coffee followed an exponential pattern, described by a series expansion function, which forms the basis for the simplified Crank solution. The range of diffusivities of the various roasts was at 10−14 to 10−15 m2/s. The temperature effect on the diffusivity can be described by the Arrhenius equation, with activation energy of 73.6 kJ/mole.
PARTICLE SIZE DETERMINATION OF FOOD SUSPENSIONS: APPLICATION TO CLOUDY APPLE JUICE
Authors: GENOVESE D.B. , LOZANO J.E.
Published: February 2007

Three different techniques were applied to determine particle size distribution (PSD) of cloudy apple juice: sedimentation‐photometry (S‐F), scanning electron microscopy (SEM) and photon correlation spectroscopy (PCS). All the three techniques found particles in a range from about 0.05 to 3 micrometers (μm = 10−6m). While calculation of PSD by SEM was based on particle number, calculation of PSD by PCS and S‐F were based on intensity of scattered light, and both weight (or volume) and projected area (or absorbed light), respectively. In order to compare results from these techniques, appropriate equations were used to convert distributions from one base to another. Three characteristic diameters were also obtained from each distribution: mean, median and modal. Characteristic diameters range from 0.88 to 2.50 μm in weight basis, 0.77 to 2.50 μm in projected area basis and 0.08 to 0.23 μm in number basis. Differences between these diameters were due to asymmetry in the distributions.
RESISTANCE COEFFICIENTS OF FITTINGS FOR POWER‐LAW FLUIDS IN LAMINAR FLOW
Authors: MARTÍNEZ‐PADILLA L.P. , GARCÍA J.A. LINARES
Published: February 2007

The calculation of head loss in valves and fittings is highly important to design food engineering processes under several pumping conditions. Nevertheless, there are few data reported to predict pressure loss in accessories for non‐Newtonian fluids in laminar flow, usually observed in many viscous fluid foods. In this study, experimental data of pressure drops as a function of the generalized Reynolds number were obtained to determine the resistance or friction loss coefficient (kf) of power‐law fluids while pumped through 1‐in. diameter stainless steel valves (butterfly and globe), and an assembly of four 90° bends. Aqueous dispersions of carboxymethylcellulose were used as a model of a shear thinning fluid. Results showed that for all the accessories evaluated, the kf values hold an inverse function with the generalized Reynolds, using the classical log‐log plot. Results are in agreement with data reported in the literature for Newtonian and power‐law fluids. The correlations obtained in this study were compared with results in previous works and they were found to be within the range reported.
RHEOLOGICAL CHARACTERIZATION OF CARBOXYMETHYLCELLULOSE SOLUTION UNDER ASEPTIC PROCESSING CONDITIONS
Authors: VAIS ANDRIANA E. , PALAZOGLU TUNC KORAY , SANDEEP K.P. , DAUBERT CHRISTOPHER R.
Published: February 2007

The rheology of Carboxymethylcellulose (CMC) solutions, which are widely used as carrier fluids in aseptic processing simulations, was studied. Effects such as time dependency, recovery, and viscoelasticity were studied. A model was developed to determine the apparent viscosity of CMC solutions as a function of shear rate, temperature, and concentration. The model can be used in process design from both a fluid mechanics standpoint and a heat transfer standpoint. It was found that the solutions behaved as pseudoplastic fluids that were irreversibly thixotropic and also viscoelastic.
COMPUTATIONAL FLUID DYNAMICS MODELING OF FLUID FLOW IN HELICAL TUBES
Authors: PALAZOGLU T. KORAY , SANDEEP K.P.
Published: February 2007

The effect of different processing parameters on the degree of mixing and axial and radial pressure drops, during single‐phase flow in helical tubes was investigated by using CFD software. Correlations were developed to calculate axial and radial pressure drops, and also the ratio of maximum to average fluid velocities. All of these quantities were found to be dependent on curvature ratio (ratio of tube diameter to coil diameter). Flow visualization experiments were performed to assess the degree of mixing in different configurations. At identical conditions, the degree of mixing was higher in the system with the large curvature ratio, which is in agreement with the simulation results. A minimum ratio of maximum to average fluid velocities of 1.61 was achieved, representing a 20% reduction in hold tube length for Newtonian fluid in laminar flow.
RADIO FREQUENCY (RF) HEATING OF STARCH SOLUTIONS UNDER CONTINUOUS FLOW CONDITIONS: EFFECT OF SYSTEM AND PRODUCT PARAMETERS ON TEMPERATURE CHANGE ACROSS THE APPLICATOR TUBE
Authors: AWUAH G.B. , RAMASWAMY H.S. , PIYASENA P.
Published: February 2007

Studies were conducted to evaluate the effect of system and product parameters on the temperature change (ΔT) across a 1.5 kW radio frequency heater operating at 27.12 MHz. Starch solutions (1 to 4% w/w) were used at three different flow rates (0.35, 0.5 and 1 L/min) and four power levels (672, 912, 1152 and 1392 W). The average heating rate of starch solutions varied from 6 to 19C/min depending on flow rate, concentration and power level. The corresponding residence time varied from 1.5 to 4.3 min. Central composite designs involving power (830 to 1234 W) and starch concentration (1 to 4% w/w) at 0.5 L/min were used to study the effects of salt, pH and sugar. As expected fluid flow rate, power level and salt concentration had significant impact (P ± 0.05) on temperature change (ΔT) across the applicator tube. Although the interaction effect of salt and concentration influenced ΔT (P < 0.05), observed trends were not clear cut. Sugar and pH had no significant (P >0.05) influence on ΔT due probably to their relatively lower conductivities. However, the interaction effect of sugar and starch concentration affected ΔT. Correlations were developed for estimating ΔT across the tube as a function of power level, concentration, pH, added salt and sugar. Finally, dimensionless correlations involving the generalized Reynolds, Prandtl, Grashof numbers, dimensionless power and loss‐factor ratios were developed for estimating the temperature ratio (U) across the RF applicator.
USE of PHYTOGLYCOGEN EXTRACTED FROM CORN to INCREASE the BOWL‐LIFE of BREAKFAST CEREAL
Authors: ANDERSON BRENT A. , SINGH R. PAUL , ROVEDO CLARA
Published: February 2007

Phytoglycogen was extracted from frozen corn using water and ethanol. the phytoglycogen powder was dissolved in distilled water, sprayed onto ready‐to‐eat breakfast cereal, and dried. the coated cereal was soaked in milk for three minutes and compared to control samples. the coated cereal showed a significant improvement in texture over control samples after soaking in milk. Peak force for control samples dropped by almost 40% after soaking, while the peak force for samples coated with phytoglycogen dropped by less than 20%. Coated samples were also found to absorb less milk than did uncoated samples. Therefore, use of a corn phytoglycogen coating could potentially be used to increase the bowl‐life of some breakfast cereals.
MOISTURE SORPTION CHARACTERISTICS of STARCH GELS. PART 1: MATHEMATICAL DESCRIPTION of EXPERIMENTAL DATA
Authors: MCMINN W.A.M. , AL‐MUHTASEB A.H. , MAGEE T.R.A.
Published: February 2007

The moisture sorption isotherms of potato starch, starch‐sugar and starch‐salt gels were determined using a gravimetric static method at 30, 45 and 60C, and over a range of relative humidities from 0.10 to 0.84. the starch gels exhibited Type II behavior, with incorporation of sugar or salt into the samples resulting in Type III form. the sorption capacity decreased with increasing temperature. the experimental data were analyzed using seven models; two‐parameter relationships (Halsey, Henderson, Smith), three‐parameter equations (Ferro‐Fontan, Guggenheim‐Anderson‐de Boer, modified‐Oswin) and four‐parameter equation (Peleg). the empirical Peleg equation and kinetic GAB model (parameters have physical significance) were found to be the most suitable for describing the sorption characteristics within the temperature range 30–60C and water activity range 0.05–0.95.
KINETICS of QUALITY CHANGE DURING COOKING and FRYING of POTATOES: PART II. COLOR
Authors: NOURIAN F. , RAMASWAMY H.S.
Published: February 2007

Color, as a quality attribute of cooked and fried potatoes, is affected by the extent and nature of heat during thermal processing. Improvement of color parameters has been made possible by the increase in knowledge of kinetics of color change. Analysis of kinetic data allows processors to minimize undesirable changes and optimize color retention. the objective of this study was to evaluate kinetics of color change during cooking and frying of potatoes. Potatoes were cut into cylinders (diameter × height: 20 mm × 20 mm for cooking and 10 mm × 20 mm for frying) and cooked in a temperature controlled water bath at 80–100C or fried in a commercial fryer at 160–190C for selected times. Color changes associated with cooked and fried potatoes were evaluated using a tristiumulus colorimeter in the L, a, b mode. For cooked potatoes, L and b values decreased while ΔE and a values increased with time at each cooking temperature. For fried potatoes, L value decreased while a, b and ΔE values increased as frying time increased. A modified first order model was used to characterize color change kinetics of both cooked and fried potatoes based on changes occurring between the initial and a maximum or minimum value. Temperature sensitivity of rate constants was adequately described by the Arrhenius and z‐value models.
SCALE‐UP and FIELD TEST of the VACUUM/STEAM/VACUUM SURFACE INTERVENTION PROCESS FOR POULTRY1
Authors: KOZEMPEL MICHAEL , GOLDBERG NEIL , DICKENS J. ANDRA , INGRAM KIM D. , CRAIG JAMES C.
Published: February 2007

The Vacuum/Steam/Vacuum surface intervention pilot plant processor was scaled up to a mobile unit that can be transported to close proximity of chicken processing plants. After several modifications to the mandrel that supports the broiler carcass in the treatment chamber to minimize mechanical damage, the unit was capable of 1.1 log cfu/mL kill of inoculated Listeria innocua and 1.4 log cfu/mL kill of inoculated E. coli K‐12. Field tests achieved 1.4 log kill of E. coli and 1.2 log kill of Campylobacter on freshly processed chicken using 3 cycles and 138C saturated steam. But, there was extensive mechanical damage. the mandrel was modified in the Eastern Regional Research Center pilot plant to eliminate the mechanical damage. With mechanical damage eliminated, the bacteria kill was 1.1–1.5 log of inoculated E. coli K‐12 with a total process time of 1.1 s.
SENSORY EVALUATION OF FOOD FIRMNESS
Authors: SZCZESNIAK ALINA S. , BOURNE MALCOLM C.
Published: February 2007

How people test foods for firmness without eating them, was studied using 131 respondents and 9 different pairs of foods representing a wide range of firmness. The results were related to correctness of judgment and objective characterization by the Instron machine. Evidence was obtained that the kind of sensory firmness test employed depends on the firmness of the food. Viscosity/ consistency, deformation, puncture, and flexure were used as the degree of ‘firmness’ increased from a low (whipped toppings) to a very high (carrots) level.
THE DETERMINATION OF POISSON'S RATIO BY COMPRESSION TESTS OF CYLINDRICAL SPECIMENS*
Authors: HAMMERLE J. R. , McCLURE W. F.
Published: February 2007

Theoretical basis is presented for determining Poisson's ratio in uniaxial compression tests of cylindrical specimens. A simplified measurement technique and instrumentation for obtaining the required parameters are described in detail. Experimental data for Centennial sweet potato flesh at 72°F and four moisture contents are provided and analyzed to give the time dependent master curve and the time‐moisture shift factor; thus, the time and moisture influenced viscoelastic property of Poisson's ratio is completely specified.