bluuebunny/crossref_metadata_2025 huggingface dataset:
BREAKAGE SUSCEPTIBILITY of SHELLED CORN DUE to REHYDRATION and REDRYING
Authors: TABIL L. G. , NOOMHORM A. , VERMA L. R.
Published: February 2007

Processing activities such as drying expose grains to temperature and moisture gradients resulting to increased susceptibility of corn breakage. the effect of rehydration and redrying rates on the breakage susceptibility of corn was compared and evaluated. Dried corn samples were rehydrated and redried artificially. Breakage susceptibility of the samples were tested using a food grinder (blender) and Instron testing machine. Treatments consisting of a cycle of rehydration and redrying represented different rates of moisture sorption. Initial sample moisture, rehydration methods and redrying temperatures were used in comparing breakage susceptibility.

Samples of low initial moisture had higher breakage susceptibility as compared to higher initial moisture samples. the rehydration method representing the highest moisture adsorption rate resulted to samples which were more susceptible to breakage than the two rehydration methods representing intermediate and slow rates of moisture adsorption. Temperature of redrying also showed significant effects with high temperatures (80°C) resulting to grains with higher breakage susceptibility compared to samples redried with unheated air (30°C). Breakage susceptibility increased when samples were rehydrated and increased much more when they were redried.
AIR DRYING BEHAVIOR of FRESH and OSMOTICALLY DEHYDRATED PINEAPPLE
Authors: RAHMAN SHAFIUR , LAMB JACK
Published: February 2007

Fick's Law of diffusion was used in the analysis of the air drying behavior of fresh (non‐osmosed) and osmosed pineapple. the drying rates of osmosed pineapples were significantly decreased due to the presence of infused solute. the effective diffusion coefficient decreased with the increasing solid gain during osmosis.
KINETIC STUDY of QUALITY LOSSES IN FROZEN SCALLOP MEATS
Authors: CHUNG SIEW LIAN , MERRITT JOHN H.
Published: February 2007

The rates of changes of texture, cook drip and free fatty acid during frozen storage of scallop meats at −30, −18, −12, −8 and −5°C were studied. Both the physical and chemical changes were found to follow first order kinetics. the activation energies for toughness, cook drip and free fatty acid were 43.6, 69.3 and 37.9 kJ/mol, respectively.
EQUILIBRIUM DATA FOR OSMOTIC CONCENTRATION of POTATO IN NACL‐WATER SOLUTION
Authors: BISWAL R.N. , BOZORGMEHR K.
Published: February 2007

Equilibrium data needed in modeling of osmotic dehydration are reported for unblanched diced potato in contact with aqueous solutions of sodium chloride. Diced potato, 1 cm cubes, were equilibrated with 0–12% (w/w) aqueous NaCl solutions at three temperatures (8, 21 and 35°C). the mass fraction of total solids nonsalt (wF3) in potato at equilibrium was modeled as a function of mass fraction of total solids in the fresh material at full turgor (wF3), concentration of NaCl in the external solution (wIB) and temperature. Using wF3 and wIB, and assuming that the activity of NaCl in the potato tissue and the external solution at equilibrium are equal, equilibrium densities were calculated based on the principle of volume additivity. the predicted and experimentally measured equilibrium densities were in close agreement.
DIFFUSION of WATER IN CEREAL‐BREAD TYPE FOOD FIBERS
Authors: DURAL NILUFER H. , HINES ANTHONY L.
Published: February 2007

A study involving water vapor diffusion in cereal‐bread type dietary fibers was conducted. the experimental diffusivity data were derived from adsorption rate measurements for water vapor in wheat bran, oat fiber, corn bran, and rice fiber at 278, 288, 298 and 310 K, using a gravimetric method. the effective bulk diffusivities were determined by employing a Fickian model for isothermal diffusion, and were subsequently correlated by an Arrhenius type expression. Thermal effects on the rate measurements were evaluated through a nonisothermal analysis. the rate at which water diffused in different fibers followed the trend: rice > oat > corn > wheat. the effective diffusion coefficients of water in all fibers were in the range of 10‐3‐10−4 cm2/s. As expected, all fiber samples were saturated faster at higher temperatures.
DIVIDED SORPTION ISOTHERM CONCEPT: an ALTERNATIVE WAY to DESCRIBE SORPTION ISOTHERM DATA
Authors: ISSE M.G. , SCHUCHMANN H. , SCHUBERT H.
Published: February 2007

The broad range of moisture sorption isotherm (MSI) data of mango is divided into two ranges of submoisture sorption isotherms (sub‐MSI), corresponding to two different ranges of water activity; the net isosteric heat of sorption (qst) is used as subdivision criterion of these two ranges. the sub‐MSI are fitted to a general elquation. the mean error is 5% for the first sub‐MSI (qst) and 10% for the second (qst≤ 0).
A NUMERICAL METHOD FOR SIMULATING HEAT TRANSFER IN HETEROGENEOUS and IRREGULARLY SHAPED FOODSTUFFS1
Authors: CALIFANO A.N. , ZARITZKY N.E.
Published: February 2007

Heat conduction during cooking of foodstuffs with heterogeneous thermal properties was simulated, mainly for irregularly shaped geometries. A code employing boundary‐fitted grids was implemented in a numerically conservative form (control volume formulation). This technique consists of finding a numerical coordinate transformation which fits a regular grid to the domain of integration. With the grid as data, coefficients for a transformed differential equation are then obtained.

The proposed model was experimentally verified on irregularly shaped pieces of beef containing a nonuniform distribution of fat. Relative errors between predicted and measured temperatures were less than 2%.

The effects of heat transfer coefficient and temperature of the cooking medium on the temperature distribution during the process were analyzed. the influence of different fat patterns was also considered.
THERMAL INACTIVATION KINETICS of TRYPSIN AT ASEPTIC PROCESSING TEMPERATURES
Authors: AWUAH G.B. , RAMASWAMY H.S. , SIMPSON B.K. , SMITH J.P.
Published: February 2007

Kinetics of thermal inactivation of trypsin (bovine pancreas) were evaluated in the temperature range, 90–130C, common to aseptic processing of high/low acid foods. Aliquots of trypsin in buffer, at three pH values, 3.8, 5.1 and 6.0, were subjected to selected heat treatments at various temperatures. Kinetic parameters were evaluated from the residual enzyme activity. Reference k and D values (at 121.1C) ranged from 0.0719 to 0.349 min−1 and 32.0 to 6.6 min, and Ea and z values ranged from 84.9 to 69.9 kJ/mole and 33.1 to 39.9C, respectively, in the pH range 3.8–6.0. the thermal inactivation resistance of trypsin in the acid and low acid pH range makes it a potential bioindicator for high temperature thermal processes.
EFFECT of ENZYMES ON MICROFILTRATION of APRICOT PUREE1
Authors: HART MARCUS R. , NG KENG C. , HANNI PETER F. , HUXSOLL CHARLES C.
Published: February 2007

In pilot plant flitration tests, using a ceramic microfilter, it was shown that pectinase was effective in increasing flux at an enzyme level as low as 75 ppm and that flux increased with time during filtration. Cellulase was shown to inhibit flux when used alone or in combination with pectinase, even though it contributed to reducing viscosity of the puree.

Both cellulase and pectinase were partially held back by the filter; usually more than half the pectinase was retained. This resulted in increased enzyme concentration with time in retentate. Retained enzymes might be used by continuously adding fresh puree with reduced enzyme to retentate after startup.
PREDICTION of BEEF CARCASS CHILLING TIME and MASS LOSS
Authors: MALLIKARJUNAN P. , MITTAL G.S.
Published: February 2007

Predictive equations to compute the chilling time, mass loss at the end of chilling, temperature history at the geometric center of round and mass loss history during beef carcass chilling were developed using validated computer models and response surface analysis. Central composite rotatable design was used to obtain quadratic response surfaces for various chilling parameters. Temperatures at the geometric center of round muscle were predicted within 95% confidence interval. Mass loss histories were also predicted within 95% confidence interval after 5 h postmortem. Temperature predictions were within ± 2C and mass loss predictions were within ± 1.0%.
THERMAL PROCESS SIMULATION of CANNED FOODS UNDER MECHANICAL AGITATION1
Authors: BICHIER J.G. , TEIXEIRA A.A. , BALABAN M.O. , HEYLIGER T.L.
Published: February 2007

This paper describes how the distributed parameter conduction‐heating numerical model was modified and tested to accurately predict the can center temperature for canned foods which exhibit combined heat transfer of pure conduction with added forced convection caused by mechanical agitation. This innovation will open the door to more widespread use of such mathematical models as part of the control system logic for making accurate adjustments to process conditions in response to unexpected retort temperature deviations on line during thermal processing of canned foods in agitating retorts.
COORDINATE SYSTEM INDEPENDENCE of SHEAR RATE DURING ISOTHERMAL SINGLE‐SCREW EXTRUSION of A NEWTONIAN FLUID
Authors: KARWE MUKUND V. , CHIRUVELLA RAMAN V. , JALURIA YOGESH
Published: February 2007

The analysis of fluid flow in a single screw extruder channel is presented by treating the screw as stationary and rotating the barrel in the opposite direction. It is shown that the calculated shear rates at the barrel and at the screw, during extrusion of a Newtonian fluid under isothermal conditions, do not depend on the choice of formulation, i.e., barrel moving or screw moving. It is also shown that they are independent of choice of coordinate system.
EVALUATION of CONTINUOUS THERMAL PROCESSES USING THERMOCOUPLE DATA and CALIBRATING REACTIONS
Authors: MILES J.J. , SWARTZEL K.R.
Published: February 2007

Twelve continuous thermal processes were evaluated with the equivalent point method based on time‐temperature histories and the destruction of Blue #2 at four different pH's to provide different kinetic parameters as calibrating reactions. the Arrhenius kinetic parameters for the four reactions were estimated under continuous flow conditions. Three were used as calibrating reactions to determine the equivalent times and temperatures for each process. the loss of blue #2 for the fourth was estimated for each process, using its kinetic parameters and equivalent points based on thermocouple and calibrating reactions. Log concentration reductions, using equivalent points based on calibrating reactions, more closely matched (slope = 0.962, r2= 0.999) actual results than did equivalent points based on thermocouple data (slope = 1.030, r2= 0.976). Thermal process estimates based on calibrating reactions were more useful to estimate kinetic parameters or product quality because they more closely represented the process actually experienced by the product.
KINETICS of OSMOTIC DEHYDRATION of COCONUT
Authors: RASTOGI N.K. , RAGHAVARAO K.S.M.S.
Published: February 2007

Osmotic dehydration rates were determined for coconut over a range of osmotic solution concentration (40–70°B) and temperature (25–45C). A semi‐empirical relation for kinetics of osmotic dehydration has been proposed, which indicates the moisture diffusion as a function of concentration of osmotic solution and its temperature. Good agreement was observed between the observed and predicted values (correlation coefficient 0.90). the effective diffusion coefficients of water in coconut during osmotic dehydration were estimated and also the activation energy of the osmotic dehydration process of coconut was found as 1.75 × 104 J/kg‐mole.
VARIABLE CONTROL of A BATCH RETORT and PROCESS SIMULATION FOR OPTIMIZATION STUDIES
Authors: FASTAG J. , KOIDE H. , RIZVI S.S.H.
Published: February 2007

A microcomputer was interfaced with a batch retort for digital PI control of the retort temperature. Six retort temperature profiles (three isothermal, sinusoidal, step, and ramp) were examined for processing pea puree to nearly the same lethality values in 211 × 400 cans. Thiamine content and steam consumption were measured. Thiamine retentions in non‐isothermal processes were greater than in the isothermal processes, but there was no significant difference in the steam consumption.

Lethality and thiamine retention were also simulated using a finite difference model for the same heating profiles, with good agreement with experimental results. the simulation suggests that differences in thiamine retention due to differing heating regimes are significant only for large lethality values and smaller cans. For F0 values smaller than 10 min, the simulation suggests that the sinusoidal heating regime will provide better thiamine retention. Limitations of the model and suggestions for future improvement are also discussed.
EFFECTS of DIPPING and WASHING PRE‐TREATMENTS ON MICROWAVE DRYING of GRAPES
Authors: TULASIDAS T.N. , RAGHAVAN G.S.V. , NORRIS E.R.
Published: February 2007

The effects of different dipping pretreatments on microwave drying of grapes was studied in a multimode cavity. Grapes pretreated with 2% ethyl oleate in 0.5% sodium hydroxide (NaOH) solution resulted in comparatively good quality raisins with lowest drying times. Pretreatment with 3% ethyl oleate in 0.5% NaOH solution led to similar product without any major advantage over the former. Grapes treated with 3% ethyl oleate in 2.5% potassium carbonate solution took longer time to dry. Grapes treated with only NaOH solution resulted in raisins of inferior quality in terms of color and appearance. the interphase mass transfer coefficients also described the effect of these chemical pretreatments. Studies conducted on the effect of washing and time of holding after the pretreatment indicated that both of these factors had no influence on drying time.
DYNAMICS of FAT/OIL DEGRADATION DURING FRYING BASED ON PHYSICAL PROPERTIES
Authors: PAUL S. , MITTAL G.S.
Published: February 2007

The dynamics of fat/oil degradation were studied by measuring the concentrations of major degradation products, polymers, decomposition products, free fatty acids and total polar materials. Regression models were fitted to predict the changes in physical properties, specific gravity, viscosity, surface tension, specific heat, dielectric constant and capacitance with fat degradation. Fat degradation affected specific heat, specific gravity and viscosity. the dielectric constant or capacitance predicts fat degradation, independent of the food fried. A parallel plate capacitor of larger capacitance was found to produce better correlation with total polar materials in the high polar region.
THERMAL DIFFUSIVITY MEASUREMENTS of WHEAT FLOUR and WHEAT FLOUR DOUGH
Authors: GUPTA T.R.
Published: February 2007

A simple technique was used to measure thermal diffusivity of whole wheat flour and whole wheat flour dough at various levels of moisture and temperatures. the experimental values showed good agreement with the calculated values. It was found that thermal diffusivity of dough increases with moisture and temperature below 60C, but above 60C its value decreases. This is attributed to physico‐chemical changes, e.g., starch gelerinization and protein coagulation. Due to these changes swelling and softening of dough occur, which reduce the ability of dough to diffuse thermal energy, thus lowering the value of the thermal diffusivity. Based on the experimental value of wheat dough at various moisture levels and temperatures, the following equation is proposed: α= (7.957 − 0.6346 M + 0.217 T + 0.008 M2− 0.00176 T2− 0.00051 M × T) × 10‐7
SIMULATION OF DYNAMIC PROPERTIES OF BATCH STERILIZER WITH EXTERNAL HEATING
Authors: LOUČKA MILOSLAV
Published: February 2007

A computer program for simulation of a sterilizer with an external recirculation heating system was developed on the basis of a requirement formulated in our previous work (Loučka and Vinkldrkovd 1990) containing the analysis and comparison of sterilization equipment with respect to technological aspects. The originally derived mathematical model provides the characteristic curves in the dimensionless form which solves many technical problems under the condition that bath temperature is reached in the required time period. From this calculation it follows that plate arrangement of the heat exchanger is significantly better than a tubular one.
FLOW MODELING OF A POWER‐LAW FLUID IN A FULLY‐WIPED, CO‐ROTATING TWIN‐SCREW EXTRUDER1
Authors: LI Y. , HUFF H.E. , HSIEH F.
Published: February 2007

The two‐dimensional flow theory of a power law fluid in a fully‐wiped co‐rotating twin‐screw extruder was investigated under steady‐state, isothermal conditions. The important distinction between this approach and previously published theories (Denson and Hwang 1980; Booy 1980; Wang and White 1989; Lai‐Fook et al. 1989, 1991) is that actual boundary conditions were used instead of boundary conditions based on the parallel plate model developed for single screw extruders. The generalized screw curves constructed for both double‐lead and single‐lead screw elements were similar in shape to those published for single screw extruders with rectangular channels. Noticeable increases in the closed discharge pressure and the open discharge flow rate were observed, which are the result of the screw geometry. Experimental results with corn meal were in agreement with theoretical predictions for single‐lead screw elements. Theoretical predictions for double‐lead screw elements using the new solution also showed reasonable agreement with experimental data from published literature after the incorporation of the intermeshing effect.
A NONLINEAR PROGRAMMING TECHNIQUE TO DEVELOP LEAST COST FORMULATIONS OF SURIMI PRODUCTS
Authors: HSU CHENG‐KUANG , KOLBE EDWARD , ENGLISH MARSHALL
Published: February 2007

Optimization programming techniques were applied to develop the least cost formulations for Pacific whiting surimi‐based seafood (PWSBS). To develop the quality constraint functions, texture and color of whiting surimi gels were determined by torsion test and colorimeter, respectively. Whiting surimi gels were produced by heating at 90C for 15 min with 2% NaCl, five final moisture contents (74, 76, 78, 80, 82%), and various combinations of beef plasma protein (0–2%), potato starch (0–8%), and two whey protein concentrates (0–8%). Due to the nonlinear constraint functions describing texture and color, a nonlinear programming search technique was required to solve the least cost model for PWSBS. Results for representative target quality constraints are reported in this study and show that whey protein concentrate both increases the texture properties and remains economically competitive with other ingredients which similarly influence functionality in PWSBS.
TEXTURAL AND VISCOELASTIC CHANGES OF CANNED BISCUIT DOUGH DURING MICROWAVE AND CONVENTIONAL BAKING
Authors: PAN B. , CASTELL‐PEREZ M.E.
Published: February 2007

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.
ANALYSIS OF MASS TRANSFER IN OSMOTIC DEHYDRATION BASED ON PROFILES OF CONCENTRATION, SHRINKAGE, TRANSMEMBRANE FLUX AND BULK FLOW VELOCITY IN THE DOMAIN OF TIME AND SPACE
Authors: YAO ZHIMING , MAGUER MARC LE
Published: February 2007

An analysis of mass transfer mechanisms in osmotic dehydration was carried out by examining the profiles of concentration, shrinkage, transmembrane flux and bulk flow velocity in the domain of time and space. The profiles were obtained through simulations using a computer simulation model that described mass transfer in osmotic dehydration based on cellular structure. It was shown that bulk flow was the main resistance for solute penetration, and the magnitude of bulk flow was affected not only by the transmembrane flux, but by internal cellular structure changes. Since bulk flow often played an important role in mass transfer during osmotic dehydration, precautions should be taken when interpreting mass transfer in osmotic dehydration using a simple pure diffusion theory.
A THREE PARAMETER EQUATION FOR FOOD MOISTURE SORPTION ISOTHERMS
Authors: LEWICKI PIOTR P.
Published: February 2007

A three parameter equation for moisture isotherms was developed and fitted to 31 food sorption isotherms. The GAB and the Peleg's models were fitted to the isotherms for comparison. Residuals and root mean square were used for assessment of the goodness of fit. The proposed equation gives fit to 28 isotherms but not as good as that obtained with the Peleg's model but much better than that found with the GAB model. Nevertheless the new equation gives higher probability of good fit to experimental data than the other two equations tested. Moreover, the new equation gives water content approaching infinity when aw= 1, a property which is not offered neither by the Peleg's nor the GAB model.
RESIDENCE TIME DISTRIBUTION OF FOOD AND SIMULATED PARTICLES IN A MODEL HORIZONTAL SWEPT SURFACE HEAT EXCHANGER1
Authors: ALHAMDAN ABDULLAH , SASTRY SUDHIR K.
Published: February 2007

The residence time distribution (RTD) of food and inert particles flowing in a swept surface heat exchanger at room temperature was investigated. The effects of selected experimental conditions on RTD include particle shape (cube, cylinder, and sphere), particle concentration (10, 20, and 30% w/v), particle type (potato, carrot, turkey, green peas, and polystyrene), fluid viscosity (water, 0.5% CMC, and 1.0% CMC), bulk flow rate (5.8 × 10−4, 7.28 × 10−4, and 8.71 × 10−4 m3/s) and shaft rotational speed (30, 60, and 90 rpm). Although turkey cubes were denser than other food particles, they moved faster than potato and carrot particles. Mean particle normalized residence time (MNPRT) of food particles (green peas) were found to be significantly higher than that of simulated particles (polystyrene). Cylindrical particles stayed longer than cubic particles in water, but not significantly in CMC solution. MNPRT values were found to be dependent on viscosity. Increasing particle concentration (up to 30%) tended to decrease MNPRT. Both bulk flow rate and shaft rotational speed tend to decrease MNPRT, thus reducing the lethality achieved. The distribution of residence time curves were narrowed by decreasing particle concentration, bulk flow rate, and shaft rotational speed, and by using fluids with high viscosity. In general, particle velocity was found to be higher than the average bulk velocity. The fastest particle velocity was found to be 3.23 times the average bulk velocity while the ratio was 0.382 for the slowest.
PREDICTING THE ELECTRORHEOLOGICAL BEHAVIOR OF MILK CHOCOLATE
Authors: DAUBERT C.R. , STEFFE J.F. , SRIVASTAVA A.K.
Published: February 2007

Electrorheology is the study of the effects of electric fields on the flow properties of fluids. These materials generally exhibit an increase in apparent viscosity and a greater yield stress over an unelectrified sample. The phenomenon requires an electric field and polar particles suspended in an insulating oil. A standard concentric cylinder viscometer, fitted with custom made electrical attachments, was converted into an electrorheometer. This system allowed control of DC voltage (0–450 Volts mm−1), fluid temperature (35C–40.5C), and shear rate (0.022 s−1– 8.744 s−1) while observing the resulting effects on the shear stress. Dimensional analysis was used to study the rheological response of milk chocolate when subjected to electric fields. Dimensionless groups were identified to explain the phenomena, and multiple regression analysis was used to predict the electrorheological flow behavior of milk chocolate. Over the ranges of input variables, the electric field‐induced forces dominated the rheological response over thermal forces, and a prediction equation for apparent viscosity was developed as a function of electric field strength and shear rate. This mathematical expression allows for prediction of milk chocolate rheology in the presence of an electric field.
THE EFFECT OF FREQUENCY AND WAVE FORM ON THE ELECTRICAL CONDUCTIVITY‐TEMPERATURE PROFILES OF TURNIP TISSUE1
Authors: LIMA MARYBETH , HESKITT BRIAN F. , SASTRY SUDHIR K.
Published: February 2007

Electrical conductivity (σ) – temperature (T) curves were determined as a function of frequency and wave form of alternating current. Turnip cylinders were sandwiched between titanium electrodes and heated ohmically to 100C using four frequencies (4, 10, 25 and 60 Hz) and three wave forms (square, sine and sawtooth). The σ‐T curve shifted upward at 4 Hz for all wave forms. Curses were not significantly different at 10, 25 and 60 Hz for sawtooth and sine wave forms, while those for square waves were not significantly different at any of the frequencies tested. A comparison of wave forms showed that σ‐T curves for square waves were shifted downward significantly with respect to sine and sawtooth waves. Heating rate increased with decreasing frequency. Changes in vegetable tissue cellular structure are believed to be responsible for these results. Further research is necessary to characterize these mechanisms.
DEVELOPMENT OF A QUANTITATIVE VIDEO‐BASED VISUALIZATION METHOD TO CHARACTERIZE THE FLOW BEHAVIOR OF FOOD PARTICULATES IN A MODEL CONTINUOUS ASEPTIC STERILIZER3
Authors: SHEFET SARID M. , SHELDON BRIAN W. , FARKAS BRIAN E. , SWARTZEL KENNETH R.
Published: February 2007

The objectives of this study were to develop a quantitative visualization tool for evaluating flow behavior of particles in a compartmented aseptic system or other flow systems. The three dimensional movement of polystyrene balls as influenced by ball diameter (0.95 and 1.90 cm), fluid flow rate (10, 20 and 30 L/min) and conveyor disk design (2 configurations) was recorded in a model heating apparatus and analyzed using motion analysis software. Ball speed and net‐to‐gross‐displacement ratio (NGDR) values were calculated for ball movement in the x;y and x;z planes. As carrier liquid flow rate increased, there was an associated increase in both the mean and standard deviation speed and NGDR values. In general, larger ball sizes yielded lower speed and NGDR values (i.e., less movement). A concave (bowl‐like) conveyor disk design as opposed to a 90° flat‐edge disk design yielded greater speed and NGDR values when carrier velocity was greater than 20 L/min. Speed and NGDR values having higher standard deviations were interpreted as having more compartmental mixing. Furthermore, speed and NGDR mean and standard deviations were highly correlated. The results of this study demonstrated the potential utility of the flow visualization method for quantitating the flow behavior of particles through tubes. Furthermore, this method should be of value to food process engineers in developing continuous aseptic processes for particulate‐containing foods.
OPTIMAL GRINDING CHARACTERISTICS OF BLACK PEPPER FOR ESSENTIAL OIL YIELD
Authors: MURTHY C.T. , RANI MEENAKSHI , RAO P.N. SRINIVASA
Published: February 2007

Black pepper (Piper nigrum L) was ground to different particle sizes at ambient conditions, and the ground material temperatures at the mills’outlet were recorded. The surface mean diameter (ds) and geometric mean diameter (dga) of the pepper grits were determined by sieve analysis. Energy for size reduction was computed using Bond's equation. The quantity of essential oil distilled, using Clevenger's method, was recorded at 30 minutes interval for each particle size. Effective diffusion coefficient (D) determined using Fick's second law, was constant (1.38 × 10−11 m2s−1) for higher oil concentrations and it was very less in lower oil concentrations. The essential oil yield was evaluated in terms of four major compounds using gas chromatographic analysis. The particle size (dgo) of about 0.7 mm was found to be optimal for distillation of essential oil.
STUDIES ON CRYOGENIC GRINDING OF CUMIN SEED
Authors: SINGH K.K. , GOSWAMI T. K.
Published: February 2007

Studies on grinding of cumin seed at various cryogenic and ambient temperatures were conducted to observe its influence on volatile oil content and its components, particle size distribution, volume mean diameter and specific energy consumption. An increase in temperature in the cryogenic range (‐160 to ‐70C) had no significant effect on volatile oil content, whereas increase in temperature in the ambient range (40 to 85C) significantly reduced the volatile oil content from 2.86 to 2.26 mL/100g. The volatile oil components, α‐pinene, β‐pinene, γ‐terpinene, p‐cymene and cuminaldehyde were not significantly affected by grinding temperature in the cryogenic temperature range. However, these components decreased significantly with increase in grinding temperature under ambient condition. With increase in temperature from ‐160 to ‐70C for 12 number of rotor ribs, the volume mean diameter of cumin powder increased quadratically from 129 to 164μm and the specific energy consumption increased from 72 to 108 kJ/kg.
SCREW CONFIGURATION EFFECTS ON RESIDENCE TIME DISTRIBUTION AND MIXING IN TWIN‐SCREW EXTRUDERS DURING EXTRUSION OF RICE FLOUR
Authors: GAUTAM AKHILESH , CHOUDHURY GOUR S.
Published: February 2007

Screw configuration effects on residence time distribution and mixing were investigated during twin‐screw extrusion of rice flour. The type, length, and position of mixing elements, and spacing between two elements significantly affected residence time distribution and mixing. Mean residence time (tmean) and extent of mixing were lower for screw profiles with KB than those with RSE. A systematic increase in tmean was observed as the mixing elements were moved farther away from the die, with longer elements, and with increased spacing between two elements.
CLARIFICATION OF EGG YOLK SUSPENSION FOR THE PRODUCTION OF N‐ACETYLNEURAMINIC ACID
Authors: KOKETSU MAMORU
Published: February 2007

Several filter aids were investigated in order to separate the hydrolyzed egg yolk suspension easily. λ‐Carrageenan was found to be the most effective flocculant for the purpose. The addition of 1.67 g λ‐carrageenan to 1 L of hydrolyzed egg yolk suspension was effective to get a clear supernatant. The ionic flocculation between the λ‐carrageenan and the egg yolk lipoprotein was presumed. Using λ‐carrageenan, N‐acetylneuraminic acid containing in the hydrolyzed delipidated egg yolk was prepared. λ‐Carrageenan did not adsorb to an anion exchange resin and could be separated completely from N‐acetylneuraminic acid, when the filtrate treated with λ‐carrageenan was applied on a column of the resin.
STUDIES ON THE EFFECT OF SURFACTANT, BLANCHING AND OSMOTIC PRETREATMENTS ON THE CONVECTIVE DRYING OF POTATOES
Authors: McMINN W.A.M. , MAGEE T.R.A.
Published: February 2007

Moisture removal from solids is an integral part of food processing. To approach the drying process of a given product it is necessary to have a knowledge of the drying kinetics. However, foodstuffs are often subjected to certain chemical and physical treatments, such as surfactant impregnation, osmotic dehydration or blanching, prior to convective drying. The drying behavior of potatoes was monitored within an experimental air tunnel dryer, with the mechanism of internal moisture migration being identified as diffusion. This was subsequently evaluated on the basis of the liquid diffusion theory. Experimental data revealed osmotic concentration as a favorable process. A 29±2% reduction in diffusion coefficient was observed following osmotic dehydration with a salt/sugar solution, however, this provided a 63±3% reduction in drying time. Structural modifications were induced by blanching, with this rendering a 10±1 and 27±2% lowering of the moisture transfer rate during drying at 30 and 60C, respectively.
MEASUREMENT OF VELOCITY DISTRIBUTION IN THE BRABENDER FARINOGRAPH AS A MODEL MIXER, USING LASER‐DOPPLER ANEMOMETRY
Authors: PRAKASH SUBBALAKSHMI , KARWE MUKUND V. , KOKINI JOZEF L.
Published: February 2007

The nonintrusive technique of Laser‐Doppler Anemometry was used to characterize flow velocity distribution in the Brabender Farinograph, which is often used to mix rheologically diverse food materials. A two‐dimensional Argonion laser Doppler system was used to obtain local velocity data at selected locations in this complex mixer. Three components of velocity were obtained as a function of time and spatial location for model fluids with characteristic rheological properties. The results revealed that the velocity distribution in the Farinograph changes with the time‐relative motion of the blades and with fluid rheology. Velocity values at locations close to the blades were much higher for the non‐Newtonian fluids than for the Newtonian fluid studied. The prevalence of static zones at regions away from the blades was noticeable, particularly in the non‐Newtonian fluids. These findings indicate that Laser Doppler Anemo metry is a valuable tool in the design and analysis of complex mixing processes.
THERMAL PROPERTIES OF SHRIMPS, FRENCH TOASTS AND BREADING
Authors: NGADI M.O. , MALLIKARJUNAN P. , CHINNAN M.S. , RADHAKRISHNAN S. , HUNG Y.‐C.
Published: February 2007

Thermal properties of fried products namely butterfly and popcorn shrimp, French toast and breading were determined for a wide range of temperature (20 to 140C), moisture content (3.3 to 87.4% w.b.) and fat content (0.005 to 0.618 kg/kg dry weight) typically encountered during deep‐fat frying. Solid density of the products ranged from 1034 to 1508 kg/m3. Solid density increased with decreasing moisture content of product. Thermal conductivity ranged from 0.03 to 0.85 W/mC. Specific heat ranged from 1.51 to 4.67 kJ/kgC. The results were in the range of published data for similar products. Temperature, moisture and fat content affected variations of thermal conductivity and specific heat. Regression equations were used to fit experimental data.
A CHICKEN CARCASS INSPECTION SYSTEM USING VISIBLE/NEAR‐INFRARED REFLECTANCE: IN‐PLANT TRIALS1
Authors: CHEN YUD‐REN , HRUSCHKA WILLIAM R. , EARLY HOWARD
Published: February 2007

On‐line trials of an industrial prototype visible/near‐infrared spectrophotometer system developed by the Instrumentation and Sensing Laboratory for inspecting poultry for diseased and defective carcasses were conducted during an 8‐day period in a slaughter plant in New Holland, Pennsylvania. Spectra (470–960 nm) of 1174 normal and 576 abnormal (diseased and/or defective) chicken carcasses were measured. The instrument measured the spectra of veterinarian‐selected carcasses as they passed on a processing line at a speed of 70 birds per minute. Classification models using principal component analysis as a data pretreatment for input into neural networks were able to classify the carcasses from the spectral data with a success rate of 95%. Data from 3 days can predict the subsequent two days’chickens with high accuracy. This accuracy was consistent with the results obtained previously in off‐line studies. Thus, the method shows promise for separation of diseased and defective carcasses from wholesome carcasses in a partially automated inspection system. Details of the models using various training regimens are discussed.
OSMOTIC DEHYDRATION OF KIWIFRUIT (ACTINIDIA CHINENSIS): FLUXES AND MASS TRANSFER KINETICS
Authors: ESCRICHE ISABEL , GARCIA‐PINCHI RICARDO , ANDRÉS ANA , FITO PEDRO
Published: February 2007

Pulsed‐Vacuum‐Osmotic‐Dehydration of kiwifruit (Actinidia chinensis) was studied using two kinds of osmotic solution: sucrose (65 Brix) and concentrated grape juice (63 Brix), three temperatures (25, 35 and 45C) and four vacuum pulse times (0, 5, 10 and 15 min). Experimental results enabled the mass transfer kinetics for water and solutes to be studied (compositional changes of the liquid fraction and changes in the liquid fraction/solid matrix ratio). The impregnation of samples, because of the vacuum pulse, was higher when concentrated grape juice was used as the osmotic solution, probably due to its lower viscosity. The effective diffusivity (De) was obtained for each experimental condition and the results show higher diffusivities for vacuum‐pulsed treatments, although differences between treatments with different vacuum‐pulse time could not be observed. De values were slightly greater for treatments with concentrated grape juice. The activation energies (Eo) were obtained by fitting the data to the Arrhenius equation.
FEED‐BACK QUALITY CONTROL IN THE BAKING INDUSTRY USING FUZZY SETS
Authors: PERROT N. , TRYSTRAM G. , GUELY F. , CHEVRIE F. , SCHOESETTERS N. , DUGRE E.
Published: February 2007

A methodology for the closed loop control of biscuit quality during baking is proposed and was validated during several experiments. This methodology involves expert knowledge which is captured in a modular way. Three modules are involved in the control strategy of the process. The first module reproduces sensory evaluation by the operator. The second module diagnoses the state of the process with respect to quality state of biscuits. Finally, a decision module supervises the actuators of the process. Different fuzzy concepts are applied within these modules and fuzzy information is processed through the control chain. Results show that using only 11 rules, all components of quality are controlled with accuracy and robustness. This is particularly interesting in the light of the complexity of the process. Such a modular approach makes it possible to follow the evolution of quality during the process, in successive steps which are easily recorded and interpreted by experts. This approach could be envisaged as an operator decision support system.
A NEW APPROACH TO MODELING AND CONTROL OF A FOOD EXTRUSION PROCESS USING ARTIFICIAL NEURAL NETWORK AND AN EXPERT SYSTEM
Authors: POPESCU OTILIA , POPESCU DIMITRIE C. , WILDER JOSEPH , KARWE MUKUND V.
Published: February 2007

The paper presents a new approach to the modeling of the start‐up part of a food extrusion process. A neural network model is proposed and its parameters are determined. Simulation results with real data are also presented. The inputs and outputs of the model are among those used by the human operator during the start‐up process for control. An intelligent controller structure that uses an expert system and “delta‐variations” to modify inputs is also proposed.
ATTRITION EVALUATION FOR SELECTED AGGLOMERATED FOOD POWDERS: THE EFFECT OF AGGLOMERATE SIZE AND WATER ACTIVITY
Authors: YAN HONG , BARBOSA‐CÁNOVAS G.V.
Published: February 2007

Investigation of the attrition of agglomerates is very important for assessing the agglomerate strength, compaction characteristics, and quality control. A one‐term exponential attrition index model and the Hausner ratio were used to study the effects of agglomerate size and water activity on the attrition kinetics of some selected agglomerated food powders. It was found that the agglomerate size and water activity played significant roles in affecting the attrition: the larger the agglomerate size and the higher the water activity, the higher the attrition index under the same tap number. The Hausner ratio was well correlated with the attrition index at high tap numbers and might be used as a simple index to evaluate attrition severity for agglomerates. Knowing the effects of agglomerate size and water activity is very useful to minimize the attrition phenomenon during the handling and processing of agglomerated powders.
A MODEL FOR PREDICTING THE GROWTH OF LISTERIA MONOCYTOGENES IN PACKAGED WHOLE MILK
Authors: ALAVI S.H. , PURI V.M. , MOHTAR R.H.
Published: February 2007

Experiments were conducted to determine growth characteristics of Listeria monocytogenes in sterilized whole milk at nine temperatures in the range of 277.15 to 308.15K (4 to 35C). Based on these data, the parameter values of the Baranyi dynamic growth model were statistically determined. Finite element software, ANSYS, was used to determine temperature distributions in milk cartons subject to a time‐varying ambient temperature profile. The space‐time‐temperature data were input to the Baranyi dynamic growth model, to predict the microbial population density distribution and the average population density in the milk carton. The Baranyi dynamic growth model and the finite element model were integrated and validated using experimental results from inoculated sterilized whole milk in half‐gallon laminated paper cartons. In all experiments, the milk cartons were subjected to the same temperature profile as the Baranyi dynamic growth model. Experimental microbial counts were within predicted upper and lower bounds obtained using the integrated Baranyi dynamic growth and finite element models. In addition, the growth curve at the mean value of initial physiological state parameter for L. monocytogenes underpredicted the microbial growth (standard error = 0.54 log (cfu/mL) and maximum relative difference = 15.49%).
EFFECTS OF CO‐IMMOBILIZATION OF PECTINASE AND AMYLASE ON ULTRAFILTRATION OF APPLE JUICE SIMULATE
Authors: CARRÍN MARÍA E. , CECI LILIANA N. , LOZANO JORGE E.
Published: February 2007

In view of its possible application in apple juice clarification, the potential of co‐immobilized pectinase/amylase by physical adsorption on a polysulfone ultrafiltration hollow fiber was examined. Solutions containing different concentrations of pectin and starch were used. The effect of various operational parameters on the production of reducing compounds, mainly galacturonic acid and maltose, was investigated. Results indicated that relative permeate flux, during ultrafiltration of starch‐pectin solutions, was up to 35% higher when commercial pectinase and amylase were co‐immobilized on a hollow fiber membrane. Although the concentration of reaction products increased up to 50% with the pectin concentration, the same was not verified when the starch content changed from 3.85 to 5.00 mg/mL. However, the reference permeate flux was improved when starch was added to substrate, independently of its concentration. Considering the size of an average starch granule, this increase in permeate flux was attributed to the removal of pectin gel by dragging. Permeate fluxes were comparable for both batch and permeate recycling operations.
EFFECTS OF FLOW INCIDENCE AND SECONDARY MASS FLOW RATE ON FLOW STRUCTURING CONTRIBUTIONS IN SCRAPED SURFACE HEAT EXCHANGERS
Authors: STRANZINGER M. , BIEDER A. , FEIGL K. , WINDHAB E.
Published: February 2007

Continuous mixing and dispersing process flows produced by scraped surface heat exchangers (SSHE) in food technology influence the microstructure of multiphase food systems and hence desired quality aspects (e.g. specific texture properties and temperature resistance). Such process flows in general depict non‐Newtonian fluid behavior. To explain and optimize the structuring mechanism of food systems (due to mixing and dispersion) treated in such process apparatus the knowledge of the local flow behavior is necessary.

In this paper a scraped surface apparatus with special narrow annular gaps including two wall scraper blades is chosen as model process (scraped surface heat exchanger (SSHE)). To get optimizing criteria in the SSHE for mixing and dispersion of shear‐thinning fluids which include structuring components, a numerical particle tracking method (NPT) was developed and used to investigate local flow behavior for various scraper blade geometries and rotational velocities. The flow fields considered are received from numerical flow simulations (finite volume method (FVM)), which have been validated with experimental velocity field measurements (digital‐particle image velocimetry method (D‐PIV)). Besides the flow field and pressure contours, values of elongational and shear rates (as components of the deformation rate tensor, causing flow structuring contributions) are compared along characteristic particle tracks in order to get a quantitative information on the mechanical history which is experienced by the structuring units. Related flow structuring contributions are defined in terms of elongational and shear energy dissipation, integrated over the particle residence times along the tracks. Hence the effects of the rotational velocity ω, the scraper blade angle β and the scraper blade gap rs on the flow structuring contributions are discussed and suggestions of SSHE geometries for food processing are given.
COMPUTER SIMULATION of CAPACITIVE RADIO FREQUENCY (RF) DIELECTRIC HEATING ON VEGETABLE SPROUT SEEDS
Authors: YANG JUN , ZHAO YANYUN , WELLS JOHN HENRY
Published: February 2007

The application of a three‐dimensional finite‐element computer program package, TLM‐FOOD‐HEATING (FAUSTUS Scientific Corp., Victoria, Canada), on the simulation of capacitive radio frequency (RF) dielectric heating of radish and alfalfa seeds was investigated. Seeds placed inside polystyrene boxes were described as a rectangle, where nonuniform boundary conditions presented complications in the simulation. Temperature and moisture dependent thermal properties and temperature and frequency dependent dielectric properties of seeds were considered in the modeling. the time‐temperature profiles of seeds at different locations within the rectangle seeds boxes were simulated. the model was then validated using experimental data. Simulated temperature distribution in seeds was consistent with the measured results. the absolute temperature differences between simulated and measured values in radish seeds packed in a 100 × 25 × 50 mm rectangle seeds box were 1.8C, 1.1C, 8.9C, and 13.6C in the center, top, edge, and bottom locations, respectively, when seeds reached about 80C, and were 0.9C, 2.4C, 7.75C, and 14.3C, respectively, in alfalfa seeds box in the same conditions.
OBJECTIVE MEASUREMENTS FOR TEXTURE IN FOODS
Authors: ESSEX E
Published: February 2007

Foods are complex systems exhibiting various degrees of elasticity, viscosity, and plasticity. Because of its complex structure and mechanical behavior, objective measurements of food texture may be influenced by a variety of test conditions, including rate of loading, the magnitude of deformations imposed upon the material, geometry of the loading surface, and localized yielding within the product tested. These sources of variance are discussed. Brief descriptions are given of methods for measuring texture of meats, dairy products, bakery foods, fresh fruits and vegetables, and processed commodities. The paper concludes with a discussion of new techniques for assessing textural qualities of foods based upon an analysis of sound, light transmission, and vibration phenomena.