bluuebunny/crossref_metadata_2025 huggingface dataset:
MULTIPLE SIEVE SIFTER PERFORMANCE USING VARIOUS COMBINATIONS OF FEED RATES, CIRCLES AND SPEEDS1
Authors: Wingfield John , Ferrer Alonso
Published: February 2007

Wheat was ground on a rollermill then sifted into several size classifications to determine how certain sifting characteristics changed when the material was subjected to changes in feed rate, sifter circle or throw and sifter speed.

The travel speed of the stocks over the sieves decreased with a decrease in average particle size. Changes in the rate of feed to the sieves had no effect on the stock travel time. Travel speed was increased for all stocks when the linear cloth speed of the sieve was increased.

Sifter efficiency, as defined by the percent of undersize material removed by each sieve in a series of sieves having the same cloth aperture, compared to the amount of undersize material going to the first sieve of the series was influenced by changes in feed rates and in sifter dynamics.

Particle size analysis of individual sieve throughs showed that when the stocks were sifted on a series of sieves having the same aperture opening size, the finest material was sifted out on the first sieve with subsequent sieve throughs becoming progressively coarser.
CONSIDERATIONS IN CALCULATING KINETIC PARAMETERS FROM EXPERIMENTAL DATA
Authors: ARABSHAHI ABOLFAZL , LUND DARYL B.
Published: February 2007

Engineers require quantitative models to design and optimize processes. In the food industry, these process models become very complex because of the unique physical/chemical characteristics and variability of the raw material. Furthermore, frequently data describing rates of reactions and/or changes in foods are generated by food scientists who are not thoroughly familiar with reaction models. Analysis of those data to obtain parameters for reaction models thus becomes critical. In this paper, calculating kinetic parameters from experimental data is examined, and suggestions are presented for determining reaction rates and temperature dependence.
DENSITY and COMPRESSIBILITY of SELECTED FOOD POWDERS MIXTURES1
Authors: CANOVAS GUSTAVO V. BARBOSA , MALAVE‐LOPEZ JOSE , PELEG MICHA
Published: February 2007

The density and compressibility of various mixtures of granular and powdered sucrose, granular malic acid, soy protein and cornstarch, at 1:3, 1:1 and 3:1 were determined and compared to those of the pure components. Unless the particles were of similar size and properties (e.g., granular sucrose and malic acid) and density and/or compressibility could not be deduced from those of the pure ingredient, as a result of the formation of new bed structures. This was particularly the case in powders exposed to elevated relative humidity conditions, in this work aw= 0.65. Because compressibility can reflect changes in the bed structure as well as deformation of the particles themselves, no correlation could be found between loose bulk density and compressibility. Therefore, each mixture ought to be treated as a new powder the bulk properties of which are determined by their particular microstructure and the water moisture of their components.
ON‐LINE VISCOMETRY FOR PUREED BABY FOOD: CORRELATION of BOSTWICK CONSISTOMETER READINGS and APPARENT VISCOSITY DATA
Authors: VERCRUYSSE M.C.M. , STEFFE J. F.
Published: February 2007

The relationship between Bostwick Consistometer (BC) readings and apparent viscosity was evaluated as an initial step in developing an on‐line viscometer for pureed baby food. Rheological properties of three baby food products (applesauce, carrots, and vegetable beef dinner) were investigated using a BC and a concentric cylinder viscometer in a temperature range from 73 to 92 C. Shear‐thinning, power law fluid behavior was found for all products. the overall correlation between results of the two methods of measurement, considered in terms of the Bostwick readings and apparent viscosity, was very poor. Developing an on‐line viscometer for pureed baby food products based on the relationship between Bostwick readings and apparent viscosity is not recommended.
POTASSIUM SORBATE PERMEABILITY of POLYSACCHARIDE FILMS: CHITOSAN, METHYLCELLULOSE and HYDROXYPROPYL METHYLCELLULOSE
Authors: VOJDANI FAKHRIEH , TORRES J. ANTONIO
Published: February 2007

Edible coatings controlling preservative migration from surface to food bulk could control surface microbial growth which is often the main cause of spoilage for many food products. In this paper we examine the potassium sorbate permeability behavior of chitosan, methyl cellulose and hydroxypropyl methyl cellulose based films. to gain an understanding of the permeation process, permeability determinations were done at 5, 24, 32 and 40°C. Permeability rates followed the Arrhenius activation energy model. A lack of breaking points in Arrhenius plots indicated that no morphological changes occur within these films in the 5 to 40°C temperature range. Activation energy values were found to be independent of film composition and were affected only by the solvent embedded in the film. This behavior was confirmed by analysis of the same permeability data using a modified Stokes‐Einstein equation.

Methyl cellulose was the most promising diffusion barrier with a permeability constant of 3.4 and 1.4×10−8 (mg/s cm2) (cm)/(mg/cm3) at 24 and 5°C, respectively. Electron microscopy was used to examine the morphological characteristics of these films and showed they have no visible pores or channels at magnifications up to 10,000.
EFFECT of VOLUME CHANGE IN FOODS ON the TEMPERATURE and MOISTURE CONTENT PREDICTIONS of SIMULTANEOUS HEAT and MOISTURE TRANSFER MODELS
Authors: BALABAN M.
Published: February 2007

Temperature and moisture content predictions of two models of simultaneous heat and moisture transfer (SHMT) in foods with and without the assumption of volume change were compared. In the first model, thermophysical and transport parameters were kept constant. In the second model, these were taken as variable functions of temperature and moisture content. Comparison of the results of both models with and without shrinkage assumption showed that there can be significant differences in predicted moisture and temperature gradients, and average moisture contents and temperatures. Biot numbers for heat and mass transfer, and the extent of overall shrinkage with moisture loss are important factors affecting these differences. the predictions of the second model were compared to experimental drying data with shrinkage. the variable‐grid finite difference method can be used successfully to solve model equations involving volume changes.
ORIFICE DISCHARGE COEFFICIENTS FOR POWER‐LAW FLUIDS
Authors: SALAS‐VALERIO WALTER F. , STEFFE JAMES F.
Published: February 2007

Orifice discharge coefficients for non‐Newtonian (power‐law) fluids (5, 7.5 and 10% corn starch solutions) were measured using a closed end pipe with different orifice diameters. Results indicate that orifice discharge coefficients, found to be in the range of 0 – 0.7, are a function of the orifice diameter, fluid velocity in the orifice and the fluid rheological properties (consistency coefficient and flow behavior index). They increase with the fluid velocity, tend to be constant at high velocities and decrease when the consistency coefficient of the solution is increasing. Orifice discharge coefficients are presented as a function of the generalized Reynolds number.
ROBOTIC HIGH PRESSURE WATER JET CUTTING of CHUCK SLICES1
Authors: HEILAND W.K. , KONSTANCE R.P. , CRAIG J.C.
Published: February 2007

With the objective of producing high quality and economical starting material for restructured beef products, the use of a high pressure water jet was investigated for excising objectionable material from slices of bone‐in beef chuck. From the limited number of tests conducted, best conditions for a clean, smooth cut were obtained with a water jet orifice diameter of 0.15 mm (0.006 in), a water pressure of 380 MPa (55,000 PSI), a slice thickness of 19 mm (3/4 in) and a linear cutting speed of 10.9 m/min (430 in/min). A preliminary cost comparison indicated that a fully automated line had a greate economic advantage over the manual method.
PRODUCTION PLANNING WHEN BATCHING IS PART of the MANUFACTURING SEQUENCE
Authors: NORBACK JOHN P. , RATTUNDE MARIA A.L.
Published: February 2007

Batching is a routine part of food production, even in many manufacturing sequences which have continuous components. Determining the correct number of batches to be produced in the face of continuous demand for final product and multiple demands on the batches from many products is a computationally complex problem. an organizational and computational scheme for tracking the impact of the batching decision is presented. the structure provides means for determining resource use patterns and for costing those patterns for a given production plan. the data necessary to drive this system are the costs, the batch formulation and yields and the other resources required by the product. the scheme is suited for electronic computation and can be rendered in a straightforward way on a microcomputer. an example illustrating how the data are organized is provided.
RICE PUFFING IN RELATION to ITS VARIETAL CHARACTERISTICS and PROCESSING CONDITIONS
Authors: CHANDRASEKHAR P.R. , CHATTOPADHYAY P.K.
Published: February 2007

The effect of rice varietal characteristics, namely, length (L): breadth (B), ratio, amylose and protein contents and processing conditions namely, extent/degree of hydrothermal treatment, degree of milling and percentage of salt addition to rice, on puffing quality were studied in detail. the L:B ratio of varieties tested showed a positive correlation (r = 0.69) with expansion ratio (ER) of puffed rice produced. Total amylose and hot water insoluble amylose contents revealed a definite pattern of relationship, with ER showing predicted peaks at 28.5% total amylose (db) and 13.5% insoluble amylose (db) for highest ER. Protein content showed a negative relationship (r =−0.79) with ER. A new method for determining extent/degree of starch gelatinization, based on Brabender hot paste peak viscosity value (viscosity of 15% slurry retained at 95°C for 20 min.) was used in this study. Normal parboiled and pressure parboiled rice having 425 BU and 240 BU peak viscosities produced highest ER of 7.5 and 9.7% respectively. A 6% milling (minimum) and a 2% salt (NaCl/CaCl2) addition during preconditioning of rice resulted in maximum ER.
TEMPERATURE MAPPING IN A POTATO USING HALF FOURIER TRANSFORM MRI of DIFFUSION
Authors: SUN XIUZHI , SCHMIDT SHELLY J. , LITCHFIELD J. BRUCE
Published: February 2007

Two dimensional temperature maps of a potato during heating were obtained using magnetic resonance imaging (MRI) techniques. the molecular pseudo self‐diffusion coefficient of the water in the potato was used as a temperature indicator. Two dimensional half Fourier transform spin‐echo and Generalized Series reconstruction techniques were used to reduce data acquisition time to about 10 s/image and to improve temperature mapping resolution. Thermocouples were implanted into the sample so that temperature and MRI data were acquired simultaneously. the error in MRI measurements caused by noise and the time delay required to collect each data set was less than 0.84C with 0.75 mm2 resolution. the average variation between MRI and thermocouple measurements was less than 0.5C. This is a promising new technique to noninvasively study heat transfer and to measure thermal properties of food materials.
FLUID‐TO‐PARTICLE CONVECTIVE HEAT TRANSFER COEFFICIENT AS EVALUATED IN an ASEPTIC PROCESSING HOLDING TUBE SIMULATOR
Authors: AWUAH G.B. , RAMASWAMY H.S. , SIMPSON B.K. , SMITH J.P.
Published: February 2007

A pilot scale aseptic processing holding tube simulator was fabricated for evaluating fluid‐to‐particle convective heat transfer coefficients at temperatures up to 110C. the simulator was calibrated to give carrier fluid flow rate as a function of CMC concentration, temperature, pump rpm and pipe diameter. Fluid‐to‐particle heat transfer coefficients (hfp) were estimated with model and real food particles held stationary in a moving liquid. Data were gathered under various conditions: CMC concentration (0‐ 1.0% w/w), flow rate (1.0 ‐ 1.9 × 10−4m3/s) and particle size (diameter: 21 and 25.4 mm; length: 24 and 25.4 mm). Depending on operating conditions, average heat transfer coefficients (hfp) ranged from 100 to 700 W/m2C with corresponding Biot numbers (Bi) ranging from 10 to 50. CMC concentration, fluid temperature and flow rate, as well as their interactions, had significant effect (p < 0.05) on hfp for both Teflon and potato particles. Some differences were observed with respect to the associated hfp for Teflon and potatoes due probably to differences in their structural/textural characteristics. Heat transfer coefficient associated with cooling were significant ly lower (p < 0.05) than those associated with heating.
INACTIVATION OF ESCHERICHIA COLI IN SKIM MILK BY HIGH INTENSITY PULSED ELECTRIC FIELDS
Authors: MARTÍN O. , QIN B.L. , CHANG F.J. , BARBOSA‐CÁNOVAS G.V. , SWANSON B.G.
Published: February 2007

The inactivation of microorganisms is the most important function in the processing of milk and dairy products. Traditionally, this purpose is realized by thermal treatment, but heat produces alterations to flavor and taste in addition to nutrient loss. The high intensity pulsed electric field (PEF) treatment should be a good alternative to heat because demonstrations have shown PEF can reduce the Escherichia coli survival fraction in aqueous solutions and model foods. In this study, PEF treatment was found to inactivate E. coli in skim milk (inoculum 109 CFU/mL) at 15C. The microorganism inactivation satisfied Hülsheger's model following a first order kinetic for both the electric field intensity and number of pulses when skim milk inoculated with E. coli was treated in a static or continuous flow chamber. PEF treatment in a continuous system when the critical electric field (Ec) and minimum number of pulses (nmin) were 12.34 kV/cm and 2.7 at 30 kV/cm and 30 pulses (0.7–1.8 μs pulse width) inactivated more microorganisms than in a static system. It has also been proven that increasing the pulse duration increases the E. coli inactivation. The inactivation of E. coli using PEF is more limited in skim milk than in a buffer solution when exposed to similar treatment conditions of field intensity and number of pulses due to the complex composition of skim milk, its lower electrical resistivity and the presence of proteins.
RESIDENCE TIME DISTRIBUTION (RTD) AND GOODNESS OF MIXING (GM) DURING CO2‐INJECTION IN TWIN‐SCREW EXTRUSION PART II: GM STUDIES
Authors: SINGH BHAJMOHAN , RIZVI SYED S.H.
Published: February 2007

Experimental residence‐time distribution (RTD) characteristics of an extrusion process may be used to estimate the extent of mixing experienced in the extruder. Using earlier theories of laminar mixing and striation thickness reduction, a new approach to estimate efficacy of mixing of two phases in the mixing zone of the extruder is proposed. Predicting the time required to achieve complete mixing and comparing it with the minimum time (plug flow time) that the extrudate spends in the mixing zone gives a ratio that can be used to evaluate the adequacy of extruder operating conditions for good mixing of gas/fluid injection and extrudate. Twin‐screw extrusion of cornmeal with carbon dioxide injection were used to investigate the effect of CO2 injection pressure and extruder screw speeds on mixing. Lower CO2 injection pressures (25 bars) and lower screw speeds (150 rpm) were theoretically shown to enhance mixing. Scanning electron micrographs (SEMs) of experimental samples taken showed smaller and more uniform cell structures for those conditions which were predicted to favor better mixing.
SIMULATION OF THE EVAPORATIVE COOLING PROCESS FOR TORTILLAS
Authors: TAYLOR T.A. , HELDMAN D.R. , CHAO R.R. , KRAMER H.L.
Published: February 2007

A simulation model was developed to predict temperature, moisture content and water activity of evaporatively cooled tortillas. The overall model was based on three parts: (1) the predicted equilibrium moisture isotherm for the product, (2) a correlation model for predicting the saturated water vapor pressure for a given temperature, and (3) the energy and mass balances for simultaneous convective heat and moisture transfer between product and cooling air. The simulation model was verified with experimental data and was found to accurately describe the behavior of the tortilla cooling system. The model predicted the simultaneous decrease in temperature, moisture content, and water activity of the product exposed to varying simulated processing conditions. It was found that cooling air velocity and temperature had the primary effect on product cooling and moisture loss rates.
DEVELOPMENT OF A LABORATORY SCALE COMPUTERIZED TEST UNIT FOR THE SIMULATION OF DEEP BED FERMENTATION AND DRYING OF ROOIBOS TEA
Authors: JOUBERT ELIZABETH , STEENKAMP ZALDEUS , MÜLLER RIKUS
Published: February 2007

A test unit for the small‐scale fermentation and drying of rooibos tea was developed to simulate deep bed fermentation and drying of the tea in practice. The data acquisition and control system consisted of an AT type personal computer interfaced with the test unit by a plug‐in type AD/DA board. Set points such as temperature, relative humidity and velocity of the inlet air could be specified for eight sequential, variable time intervals. Good control of dry bulb temperature and velocity of the inlet air was obtained, taking into account the restrictions placed on the system by the hardware. The maximum air velocity that can be used with a bed depth of 50 mm, without formation of voids, was determined as 1.8 m/s. Precautions should be taken to ensure uniform air distribution and bed depth. Good quality tea was obtained after fermentation and drying in the test unit.
GLASS TRANSITION TEMPERATURE (Tg) AND WATER ACTIVITY (aw) OF DEHYDRATED APPLE PRODUCTS
Authors: WELTI‐CHANES JORGE , GUERRERO JOSE A. , BARCENAS MARIA E. , AGUILERA JOSE M. , VERGARA FIDEL , BARBOSA‐CANOVAS GUSTAVO V.
Published: February 2007

The onset glass transition temperature (Tgo) of Granny Smith apple products was evaluated as a function of drying conditions (air drying and freeze‐drying) and moisture and water activity (aw) levels. Tgo was determined in the 0–0.75 aw range, and it was found to have a maximum value at aw= 0 (Tgo= 4.5 ± 1.6C) for freeze‐dried apple and a minimum value at aw= 0.75 (Tgo= ‐81.4 ± 0.1C) for freeze‐dried apple juice. A linear relationship between Tgo and aw was obtained in all cases. Theoretical Tgo values at aw= 0 were calculated using these equations, and were within the range of 3.0C (freeze‐dried apple) and 10.5C (apple dehydrated at 30C). When Gordon and Taylor's linear model was applied to the experimental data of all the apple products, K values within the range 2.4 (freeze‐dried apple juice) and 3.6 (apple dehydrated at 60C), and the theoretical Tg of solids values at aw= 0 between the range ‐16.3C (freeze‐dried apple juice) and ‐1.9C (apple dehydrated at 60C) were obtained. No effect of the type of drying on the value of Tg was detected.
A METHOD FOR DETERMINING THE CONVECTIVE HEAT TRANSFER COEFFICIENT DURING IMMERSION FRYING
Authors: HUBBARD LYNN J. , FARKAS BRIAN E.
Published: February 2007

The convective heat transfer coefficient is a useful parameter in characterizing heat flow across a fluid/solid interface when the fluid flow field is complex and solution of the coupled transport equations impractical. While convective heat transfer coefficient values for many unit operations have been tabulated, the boiling phase of immersion frying has not been quantified. The objective of this study was to develop a laboratory method for the measurement of the convective heat transfer coefficient during immersion frying. The method that was developed was applied to the immersion frying of potato cylinders at an oil temperature of 180C. The convective heat transfer coefficient was initially 300 W/m2K, it increased sharply to 1100 W/m2K, and gradually decreased to 300 W/m2K over the duration of the process. Use of this new method will allow the study of the effects of oil temperature, oil quality, product shape/size, and product quality on heat transfer coefficients.
MODELING THE TEMPERATURE EFFECT ON THE FLOW BEHAVIOR OF SWEET POTATO PUREE1
Authors: KYEREME MICHAEL , HALE SCOTT A. , FARKAS BRIAN E.
Published: February 2007

A study was conducted to investigate the effect of temperature on viscosity of sweet potato (SP) puree. Rheological data of the puree were measured using a Bohlin VOR Rheometer. Shear rates employed ranged from 0.01–921 s−1. Thermal scans were run at 15, 25, 40, 60, 75, and 90C. The puree exhibited “shear thinning” behavior with a yield stress value of 10 Pa at each temperature tested. The characteristic of the flow behavior of the puree was determined by fitting the experimental data to Herschel‐Bulkley, Casson and Modified Casson models. The model with the best fit was then used to represent the combined effect of shear rate and temperature on the apparent viscosity of SP puree in a model based upon the Modified Casson model. The model was validated using data for SP puree samples at 50C. Results showed that, within the experimental conditions used in this study, the model could adequately predict apparent viscosities of sweet potato puree processed at different temperatures.
LUMPED‐PARAMETER APPROACH FOR PREDICTION OF DRYING KINETICS IN FOODS
Authors: FONTAINE J. , RATTI C.
Published: February 2007

Drying kinetics of the product are the most important data required for the design and simulation of air dryers. This essential information can be obtained through simple lab‐scale experiments. Nevertheless, due to the uncertainty of the process, specially when dealing with biological materials, all the necessary data at different operating conditions are not usually available. On the other hand, drying kinetic models are either too simple to expect reasonably good predictions, or too complicated to be applied easily.

The key assumptions of a previously developed lumped‐parameter model for air drying kinetics were revised to examine their application to biological materials. A short cut method has been developed to simulate kinetic curves from a minimum number of experimental data. A simple parameter study was carried out to detect the most important variables that affect the mass transfer Biot number in order to predict kinetics data safely. Experimental (hot air) drying curves for bananas, grapes and mushrooms were obtained in a lab scale dryer, at different air temperatures (50 to 70C) and air velocities (1 to 3 m/s). A comparison between experimental and predicted data was done for different operating conditions.
EFFECT OF INSOLUBLE PARTICLES UPON SOLID INCLUSION LEVELS IN ICE FORMED ON A SUBCOOLED STAINLESS STEEL SURFACE
Authors: CHEN PING , CHEN XIAO DONG , FREE KEVIN W.
Published: February 2007

This study employed an insoluble solid particle, i.e. a potato starch used as an example, to investigate the impact of the concentration of such particles suspended in water (with solid loading of 5, 10, 20 and 30 wt%) upon the solid inclusion levels in ice layers formed on a sub‐cooled smooth stainless steel plate surface. The effects of ice growth rate, bulk concentration and suspension velocity on insoluble solid inclusion, i.e. potato starch mass fraction, in ice layer were studied. The experiments, where potato starch is added into aqueous sucrose solutions or the reverse where sucrose is added into starch suspension, were also carried out to investigated effect of the starch particles on sucrose inclusion in ice and effect of solute (sucrose) on starch particle inclusion in ice. It has been found that solid inclusion in ice increases with increasing bulk concentration and average ice growth rate, at constant solution and coolant velocities, and increasing suspension velocity can help pure ice formation. The average distribution coefficient of sucrose in ice layer formed from sucrose solution does not appear to be affected by the addition of potato starch. However, the average distribution coefficient of potato starch in ice layer formed from suspension is influenced by sucrose concentration quite significantly.
INFLUENCE OF FLOW REGIMES ON TEMPERATURE HETEROGENEITIES WITHIN A SCRAPED SURFACE HEAT EXCHANGER
Authors: DUMONT ERIC , VALLE DOMINIQUE DELLA , FAYOLLE FRANCINE , LEGRAND JACK
Published: February 2007

In industrial applications, fluids processed in scraped surface heat exchangers often show large temperature heterogeneities at the exchanger outlet. Our study deals with the thermal evolution of model fluids, Newtonian and non‐Newtonian in heating or cooling conditions and allows us to link the phenomena of appearance and disappearance of temperature heterogeneities with the changes in the flow pattern within the exchanger. Based on literature data dedicated to scraped surface heat exchangers as well as to annular spaces without blades, we have shown that thermally homogeneous products can be obtained when Taylor vortices appear in the exchanger. Studies done on the exchanger with and without blades show that the thermal behavior is basically the same for both geometries but with a difference in critical Taylor numbers value for change in heat transfer regime. The presence of blades promotes the appearance of instabilities at lower values of generalized Taylor number (Tag= 10 with blades; Tag= 39 without blades). It shows as well, that the value of critical Taylor number in scraped surface heat exchanger closely depends upon the flow‐rate even for very low values for Reaxg (Reaxg < <1).
FLOW PROPERTIES OF MALT CONCENTRATE‐SWEETENED CONDENSED MILK MIXTURES
Authors: TEJINDER S.
Published: February 2007

The rheological characteristics of various malt extract concentrate‐sweetened condensed milk mixtures in the ratios of 50:50, 60:40, 70:30 and 80:20 (w/w) were studied at 30 to 80C, using a coaxial viscometer. The magnitudes of flow behavior index varied from 0.42–0.93. Experimental temperatures and concentrations of sweetened condensed milk considerably affected pseudoplasticity, consistency index and yield stress values of the mixtures. At 60 to 80C, the 60:40, 70:30 and 80:20 mixtures showed spectacularly higher flow behavior index values than those of the 50:50. The yield stress values increased with increasing temperature. The increases were considerably high in the 50:50 mixtures. The hulless barley malt concentrate‐sweetened condensed milk mixtures, however, were mildly non‐Newtonian and showed decreases in the values for yield stress with increasing temperatures. The activation energy values for flow behavior index and yield stress were negative in magnitudes, whereas those of consistency index were positive, which ranged from 1.6 to 15.0 Kcal/g mole.
PILOT PLANT FOR OSMOTIC DEHYDRATION OF FRUITS: DESIGN AND EVALUATION
Authors: VALDEZ‐FRAGOSO A. , MUJICA‐PAZ H. , GIROUX F. , WELTI‐CHANES J.
Published: February 2007

This work proposes a pilot scale equipment for osmotic dehydration (OD) of apple cubes that consists of a novel agitation‐immersion device, a bag filter and a vacuum evaporator to conduct simultaneously the OD process, filtration and reconcentration of the osmotic solution (OS). The functional method analysis was used to design the pilot plant. Apple cubes (∼1 cm3) were dehydrated using a 60 ° Brix sucrose syrup OS at 50C and a syrup/fruit ratio of 5. OD was conducted either with or without reconcentration of the OS. During the OD process particles of fruit were eliminated from the OS by filtration and the OS concentration was kept at 60 ° Brix by reconcentration in the evaporator. A comparison of the dehydration parameters of apple cubes obtained at pilot scale to those obtained at laboratory scale was done to evaluate the performance of the pilot equipment. The results show that the proposed set‐up can be suitable for commercial production of osmodehydrated fruits.
DRYING of COFFEE BERRIES IN A VIBRATED TRAY DRYER OPERATED WITH SOLIDS RECYCLE and SINGLE‐STAGE1
Authors: FINZER J.R.D. , LIMAVERDE J.R. , FREITAS A.O. , JÚNIOR J.R. LIMAVERDE , SFREDO M.A.
Published: February 2007

A vibrated tray dryer was tested for drying coffee berries. It consists of a vertical chamber (0.33 m × 0.18 m × 1.30 m) provided with four trays. the trays are supported by a vibrated shaft. Experimental tests were carried out at a vibration amplitude of 1 mm and at a variable frequency. the process itself consisted of feeding the vibrated tray dryer with an initial mass of coffee berries: after leaving the dryer through the discharge channel, the berries were fed again to the top of the dryer by a bucket elevator (intermittent operation with recycle of the coffee berries). Drying tests were carried out with drying air velocity of 2.4 m/s. the drying air control temperature was related with the temperature of the coffee berries at the discharge (under 45C). the drying time required for coffee berries to reach 12.6% (wb) moisture was 28 h, initial mass (moisture of 67% wb) was 5.54 kg. In this work the influence of vibration in single‐stage drying is also shown. the single‐stage operation shows that vibration (besides promoting the conveyance of coffee berries) also reduces the time of drying.
FLOW BEHAVIOR of PROCESSED CHEESE MELTS
Authors: YOON WON B. , McCARTHY KATHRYN L.
Published: February 2007

Flow behavior of processed cheese melts during pipe flow was investigated using a magnetic resonance imaging (MRI) tube viscometer technique. the technique utilized an MR velocity profile and an independent pressure drop measurement to evaluate flow properties. the test fluids were three commercial processed cheese products which were evaluated at a number of volumetric flow rates under melt conditions. MR image analysis was performed using a graphic user interface Matlab program. the three processed cheeses were best characterized as shear thinning power law fluids with flow behavior indices that ranged from 0.28 to 0.40 and consistency indices that ranged from 10 to 79 Pa sn over the shear rate range of 0.1 to 10 s−1. These flow properties are relevant to the mixing and pumping of these products under melt conditions during manufacture.
PREDICTION of FLOW IN MIX‐PROOF VALVE BY USE of CFD ‐ VALIDATION BY LDA
Authors: JENSEN BO B.B. , FRIIS ALAN
Published: February 2007

This study forms the basis to achieve quantitative knowledge on the link between hydrodynamics and good hygienic design of closed processing equipment. Knowledge of flow patterns and parameters in process equipment are required to investigate effects of hydrodynamics on cleaning processes. This study was done on a spherical shaped mix‐proof valve (MPV). Flow were predicted by Computational Fluid Dynamics (CFD) and validated by data obtained from experiments using laser sheet visualization and laser Doppler anemometry. Correction of the measured velocities and probe location was required as refraction of laser beams through the curved surfaces of the valve house changes both intersection angle and intersection location. CFD simulations were performed by use of both the standard wall function and the two‐layer model of Norris and Reynolds for near‐wall description. the importance of resolving the near‐wall region is shown. Fully 3D flow patterns were identified and valuable information was obtained for further investigations concerning prediction of cleanability in the MPV based on knowledge of the hydrodynamics herein.
SAFETY and QUALITY EVALUATION of A YOGURT‐BASED DRINK PROCESSED BY A PILOT PLANT PEF SYSTEM
Authors: EVRENDILEK G.A. , YEOM H.W. , JIN Z.T. , ZHANG Q.H.
Published: February 2007

Yogurt‐based drink samples were prepared by mixing plain yogurt, water, sugar, and strawberry flavored fruit syrup. the samples were treated by both the mild heat (60C for 30 s) combined with a pilot plant pulsed electric field (PEF) system and the mild heat only in order to determine changes in the product safety and quality. Changes in the product safety were measured as microbial count, and changes in the product quality as L, a, b, oBrix and pH values. the treated and control samples were stored at 4 and 22C for microbial, physical and sensory evaluations. Since the 60C‐treated samples exploded after 14‐day storage, the safety and quality evaluations for 91 days were performed for the 60C? and control samples, only. Microbial count of the 60C? samples was significantly lower than that of the control samples at the two temperatures for the 91‐day storage (P < 0.05). There was no significant difference in the L, a, b values, oBrix and pH between the control and 60C? samples (P < 0.05). the control and 60C? samples revealed no significant difference in the selected sensory attributes (P < 0.05).
MEASUREMENT OF TEXTURE PARAMETERS OF FREEZE‐DRIED BEEF*
Authors: REIDY G. A. , HELDMAN D. R.
Published: February 2007

A modified texture profile analysis with the Instron Universal Testing Apparatus was used to measure hardness and chewiness of precooked freeze‐dried beef cubes in order to determine the influence of processing and reconditioning. Two different plate temperatures were used during freeze‐drying, and the resulting product was reconditioned at four different water activities in addition to the dry and fully rehydrated product. Reconditioning temperatures of 52, 70, and 100°F were investigated. The results revealed that the hardness and chewiness values were the highest at water activities of 0.4 to 0.6 and with the product freeze‐dried at a plate temperature of 105°F. The influence of reconditioning temperature was inconsistent, apparently due to an interaction between the water activity and the plate temperature.
RELATIONSHIP BETWEEN CERTAIN PHYSICAL‐CHEMICAL MEASUREMENTS AND SENSORY APPRAISALS OF APPLE TEXTURE
Authors: BOWMAN F. , KYLEN A. M. , ADAM S. F.
Published: February 2007

Apples were selected as the test medium to provide information about the relative value of physical‐chemical measurements as predictors of sensory appraisal of texture. Sensory, shear force, moisture, pH and protopectin/total pectin measurements of textural parameters for five variety‐lots, after various storage periods, were treated by multiple regression, analysis of variance, and covariance and path analyses. Statistical treatments revealed relationships that were clearcut and certain trends that appear to be meaningful. Panel scores were not well predicted by objective measurements with one exception. Shear force was an excellent predictor for crispness of Colorado Red Delicious. Tenderness of Golden Delicious increased as storage increased and protopectin/total pectin decreased, whereas losses of crispness and juiciness were small and inconsistent. Overall results of sensory and physical‐chemical tests for Winesap and Red Delicious were rather consistent in that tenderness increased and juiciness decreased linearly with the length of storage.
EFFECT OF CALCIUM ON THE TEXTURE PROFILE OF IRRADIATED CARROTS, BEETS AND POTATOES *
Authors: Jr L. M. MASSEY , WOODAMS E. E.
Published: February 2007

Abstract. Addition of calcium as a firming agent to fresh vegetable tissues softened by gamma radiation was studied. With tissues given pasteurizing doses (100 Krad), it was found that most of the texture profile parameters could be effectively restored in beets but not in potatoes. With tissues given sterilizing doses (2 Mrad), none of the texture profile parameters could be restored in beets or in carrots.
THE TEXTURE OF COD MUSCLE
Authors: LOVE R. M. , ROBERTSON I. , SMITH G. L. , WHITTLE K. J.
Published: February 2007

Data on moisture, protein content and pH (after 24 h in ice post mortem) of the flesh of cod of different sizes, captured during several fishing expeditions from Aberdeen to northern fishing grounds in spring and autumn, have been examined in relation to the texture of the cooked material. It is concluded that large fish are slightly tougher than small fish, even when the pH is the same. In addition, the pH of large fish is often lower than that of small fish, so the relative toughness of large fish is enhanced. However, the size‐pH relationship is clearly defined only in well‐fed fish at certain times of the year. At other times, when food is scarce, the post‐mortem pH of the muscle of all sizes of cod varies within wide limits, so that size no longer appears to influence the texture.

Of the parameters studied, the post‐mortem pH correlated best with the texture after cooking. Since fish with a high pH usually have a high water content, there was also a correlation between texture and moisture. However, the protein content seemed to exercise a negligible influence on texture, an unexpected finding considering that protein accounts for nearly all the ‘substance’ of white fish flesh after the water has been removed.
DEFINITION AND MEASUREMENT OF MEAT TEXTURE IN MILITARY DEVELOPMENT AND PROCUREMENT
Authors: TUOMY JUSTIN M.
Published: February 2007

The need for improved texture evaluation methods in meat product development and procurement is discussed with emphasis on problems facing the Armed Forces. It is pointed out that inexpensive, reproducible, simple methods are needed similar to, for example, the rapid moisture analysis equipment now being used in chemical evaluation of foods.
TEXTURE MEASUREMENT IN MEAT BY SENSORY EVALUATION*
Authors: LARMOND ELIZABETH
Published: February 2007

Various sensory evaluation methods have been used to measure texture in meat. While some methods are more suitable than others, more work must be done before any one can be recommended as a standard method. Other aspects which require special attention are cooking of samples, selection of reference samples and the multicomponent nature of texture.
INTERPRETATION OF FORCE‐DEFORMATION CURVES FROM THE SHEAR‐COMPRESSION CELL*
Authors: VOISEY PETER W.
Published: February 2007

The action of the shear‐compression cell on nine foods was observed through a clear plastic wall installed in the cell. The results confirm that it is incorrect to assume that the peak force always reflects the shear strength of the food. Rupture was generally indicated by a change in the slope of the force‐deformation curve. The mnner of sample rupture is diverse and complex, and is affected by the food properties and the way these change during compression. Rupture occurs in a progressive manner; the progression is affected by the properties of the tested food and the cell action, an important coneideration in interpreting the resulting curves.

Several aspects that affect the interpretation of the force‐deformation curves fmm this and other empirical test cells are discussed. It is concluded that a direct observation of the mode of action of test cells on the food is a valuable aid to interpreting the results.
LIQUID TEXTURE PERCEIVED IN THE MOUTH1
Authors: KOKINI J. L. , KADANE J. B. , CUSSLER E. L.
Published: February 2007

Statistical analysis of subjective assessments obtained by ratio scaling suggested that a ten attribute vocabulary describing liquid texture in the mouth could be reduced to a smaller number without great loss of predictive power, Three attributes, “thickness,”“smoothness,” and “slipperiness,” which could best predict the remaining seven were selected for further study. Each attribute was found to be closely related to a specific force in the mouth. “Thickness” was shown to be proportional to the viscous force between the tongue and the roof of the mouth. “Smoothness” seemed to be inversely proportional to the frictional force caused by the contact between the tongue and the mouth. “Slipperiness” was shown to be inversely proportional to a known average of viscous and frictional forces.
A NOTE ON THE SENSITIVITY OF FINGERS, TONGUE AND JAWS AS MECHANICAL TESTING INSTRUMENTS
Authors: PELEG M.
Published: February 2007

Deformation of a specimen between the fingers or in the mouth usually results in a significant deformation of the contacting tissues. This implies that the mechanical response is related to both deformations or, in other words, to the mechanical resistance of the combined systems. Since the latter form an in‐series configuration, the combined mechanical resistance (Mc) is given by:

where M1 and Mx are the resistance of the sensory testing system and the test specimen, respectively. Thus, Mc can be a function of the geometry and the rate of force application. The equation provides a simple explanation as to why there are differences in the sensing range between the fingers and the jaws and why the human senses are practically insensitive to hardness beyond certain levels. The model indicates that the sensitivity decreases rather rapidly after the ratio Mx/M1 becomes greater than about 0.05, but leaves unanswered the question whether, or to what extent, we can compensate for the loss of sensitivity by additional information or modification of the testing procedure.
MILK GEL STRUCTURE. X. TEXTURE AND MICROSTRUCTURE IN CHEDDAR CHEESE MADE FROM WHOLE MILK AND FROM HOMOGENIZED LOW‐FAT MILK1
Authors: EMMONS D. B. , KALAB M. , LARMOND E. , LOWRIE R. J.
Published: February 2007

Reduced‐fat cheese (17% fat, 44% moisture) was considerably firmer and more elastic than full‐fat cheese (35% fat, 35% moisture), even though the moisture levels in the nonfat matter (MNFM) of the cheese were the same, at 54%. Electron microscopy and compositional analysis revealed about 30% more protein matrix in the reduced‐fat cheese. Apparently more of this matrix must be cut or deformed in sensorial and texture assessments. A practical implication is that MNFM should be slightly higher in the reduced‐fat cheese than in full‐fat cheese to achieve more similar texture.

Homogenization of milk tended to increase the moisture content and decrease firmness and elasticity, but not markedly. The smaller fat globules, per se, did not apparently affect texture as measured in these experiments. Curd granule junctions were prominent in nonhomogenized‐milk cheese, because large fat globules were lost at the granule surfaces leaving protein‐dense junctions; those in homogenized‐milk cheese were less apparent because the protein‐dense areas, which resulted from the loss of small fat globules, were narrower.

Sensory and textural parameters for firmness and elasticity were inter‐correlated. The Bite Test was more useful than Instron measurements of deformation (20%), apparently because the latter was markedly affected by a slight openness in the cheese.
MILK GEL STRUCTURE. XI. ELECTRON MICROSCOPY OF GLUCONO‐δ‐LACTONE‐INDUCED SKIM MILK GELS1
Authors: HARWALKAR V. R. , KALAB MILOSLAV
Published: February 2007

Gels were prepared from fresh and reconstituted skim milk (10–30% total solids) using glucono‐δ‐lactone as the acid precursor within the pH range of 4 to 6.

Firmness of glucono‐δ‐lactone‐induced skim milk gels increased with (a) decrease in pH of skim milk having the same total solids content, (b) increase in total solids at a given pH, (c) pre‐heating skim milk to 90°C, and (d) adding glucono‐δ‐lactone at a higher temperature.

Electron microscopy revealed that in condition (a) larger sizes of casein micelles (particles) were associated with a higher firmness whereas in conditions (b), (c), and (d) the increased firmness was correlated with decreased micelle sizes. The relation between rheological behavior and microstructure of glucono‐δ‐lactone‐induced skim milk gels was more dependent upon the micellar arrangement than upon the size and shape of the casein micelles. Conditions which led to large casein micelle clusters and chains in conditions (b), (c), and (d) resulted both in severe syneresis and in weaker gels.

An unusual phenomenon was observed in skim milk gels made at pH 5.5, particularly at the lower total solids content (10%): the casein particles consisted of a solid core surrounded by an outer lining, 0.03–0.05 μm thick, which resembled a membrane‐line structure; there was a free annular space of 0.05 to 0.08 μm between the lining and the core. The existence of this structure was confirmed by thin‐sectioning and freeze‐fracturing techniques.
RELATIONSHIPS BETWEEN SENSORY CRISPNESS AND OTHER SENSORY AND INSTRUMENTAL PARAMETERS1
Authors: VICKERS ZATA M. , CHRISTENSEN CAROL M.
Published: February 2007

Twenty subjects judged the crispness, loudness, and firmness of sixteen food samples by both biting and chewing and by only biting the foods. These subjects also scored the foods for thirteen textural qualities. Instrumental measures of slope, peak force, and deformation to fracture were obtained for the sixteen foods from a snap test at four deformation rates. Whether a subject judged an attribute by the bite or the bite and chew technique made little or no difference in the sensory judgments. Crispness appeared to be very closely related to loudness and less closely related to firmness. Loudness of the chewing sounds was more closely related to crispness than to firmness. Of the sensory qualities studied, loud, snap, and crackly were the three most closely related to crispness. Of the instrumental parameters Young's Modulus generally had the highest correlation with the crispness of all foods and peak force generally had the highest correlation with firmness. Deformation rate had minimal effects on measures of flexure or peak force, but its effects on Young's Modulus were frequently large and irregular. A vibrotactile‐acoustical hypothesis for crispness is proposed.
STRUCTURAL FAILURE IN SELECTED RAW FRUITS AND VEGETABLES1
Authors: DIEHL K. C. , HAMANN D. D. , WHITFIELD J. K.
Published: February 2007

A torsion test was developed for studying the structural failure of selected raw fruits and vegetables. Apple, melon and raw potato flesh were tested at a shear strain rate of approximately 0.26s‐1 in torsion and uniaxial compression. Low strain modulus values were determined in addition to shear stresses and normal strains at failure.

Results corroborated the maximum normal strain failure criterion proposed by Segerlind and Dal Fabbro (1978) for apples and suggested its application to potatoes and melons if true strains are used rather than engineering strains. The maximum shear stress theory also seemed to be a possible failure criterion for potatoes. Results comparing compressible and incompressible materials suggest that bulk strain affects the shear stress at failure. The observed failure planes supported the quantitative results for stresses at failure. Scanning electron micrographs indicated that the cellular failure occurred in the cell wall, regardless of whether it was due to tension,

Varying specimen lengths or diameters had negligible effects on the uniaxial compression modulus but did affect the shear stress at failure in a manner yet to be satisfactorily explained.
MECHANICS OF FAILURE IN FRUITS AND VEGETABLES
Authors: HOLT J. E. , SCHOORL D.
Published: February 2007

An understanding of mechanical failure in fruits and vegetables is essential to the reduction of damage in processing, handling and transport operations and to the evaluation of textural characteristics of foods. This paper proposes a theory of failure for solid horticultural materials based on the classification of failure as cleavage, slip or bruising. For each of these three modes of failure, the role of intensity of loading or stress in initiating failure is described. It is shown that cleavage is a normal stress phenomenon and that slip and bruising are shear stress phenomena. The mechanical properties of horticultural produce are described in terms of cleavage strength, slip strength and bruising strength; properties which may vary with ripening and loading conditions.

A failure diagram is constructed by superimposing strength boundaries on the normal and shear stress axes of the Mohr's circles representation of the applied stress state. This novel diagram is shown to apply to selected fruits and vegetables. The model can be extended to include buckling. It is shown that horticultural materials do not fail according to one failure criterion alone, but fail, on a rising load, according to the current strength boundary first encountered by an expanding stress state. Potatoes, for example, may fail by cleavage, slip or bruising, depending on the loading conditions.