bluuebunny/crossref_metadata_2025 huggingface dataset:
Pineal indoleamines and vitamin E reduce nitric oxide‐induced lipid peroxidation in rat retinal homogenates
Authors: Siu Andrew W. , Reiter Russel J. , To Chi H.
Published: February 2007

Abstract: Oxidative damage to retinal cell membranes can lead to sight‐threatening ocular diseases. Pineal indoleamines are naturally located and synthesized in the retina, and they possibly protect the retina from oxidative cell damage. In this study, we compared the efficacy of three different pineal indoleamines (melatonin, N‐acetylserotonin, and pinoline) with vitamin E, a well‐known antioxidant, against nitric oxide (NO)‐induced lipid peroxidation (LPO) in rat retinal homogenates. The possible synergistic effect of these agents was also studied. Retinal homogenates were incubated with sodium nitroprusside, which releases NO'. The LPO product, malondialdehyde (MDA), provided an index of cell damage. The results show that vitamin E and indoleamines significantly reduced MDA levels in a dose‐dependent manner. When vitamin E was combined with the indoleamines, the protection was synergistically enhanced. In summary, under conditions where cellular homogenates are used (a) vitamin E and the three pineal indoleamines protected the retinal cells from NO‐induced LPO damage; (b) the efficacies of each of these compounds had the following relationships: vitamin E > N‐acetylserotonin > pinoline > melatonin; (c) vitamin E acted synergistically with indoleamines in combating oxidative retinal damage. Whether these same associations would exist in vivo after treatment with these compounds is unknown. The pharmacological potential of indoleamines, possibly in combination with vitamin E, in preventing retinal pathogenesis deserves further investigation.
CREB phosphorylation and melatonin biosynthesis in the rat pineal gland: Involvement of cyclic AMP dependent protein kinase type II
Authors: Maronde Erik , Wicht Helmut , Taskén Kjetil , Genieser Hans‐Gottfried , Dehghani Faramarz , Olcese James , Korf Horst‐Werner
Published: February 2007

Abstract: Phosphorylation of cyclic AMP response element binding protein (CREB) at amino acid serine 133 appears as an important link between the norepinephrine (NE)‐induced activation of second messenger systems and the stimulation of melatonin biosynthesis. Here we investigated in the rat pineal gland: 1) the type of protein kinase that mediates CREB phosphorylation; and 2) its impact on melatonin biosynthesis. Immunochemical or immunocytochemical demonstration of serine133‐phosphorylated cyclic AMP regulated element binding protein (pCREB) and radioimmunological detection of melatonin revealed that only cyclic AMP‐dependent protein kinase (PKA) inhibitors suppressed NE‐induced CREB phosphorylation and stimulation of melatonin biosynthesis, whereas inhibitors of cyclic GMP‐dependent protein kinase (PKG), mitogen‐activated protein kinase kinase, protein kinase C, or calcium‐calmodulin‐dependent protein kinase (CaMK) were ineffective. Investigations with cyclic AMP‐agonist pairs that selectively activate either PKA type I or II link NE‐induced CREB phosphorylation and stimulation of melatonin biosynthesis to the activation of PKA type II. Our data suggest that PKA type II plays an important role in the transcriptional control of melatonin biosynthesis in the rat pineal organ.
Melatonin‐induced inhibition of proliferation and G1/S cell cycle transition delay of human choriocarcinoma JAr cells: Possible involvement of MT2 (MEL1B) receptor
Authors: Shiu Stephen Y. W. , Li Li , Xu Jian N. , Pang Celia S. , Wong Joseph T. Y. , Pang Shiu F.
Published: February 2007

Abstract: Melatonin, the pineal neurohormone, is an evolutionarily conserved photoperiodic signaling molecule with diverse functions that include the entrainment of human circadian rhythms. Although evidence supporting a direct inhibitory action of melatonin on human cancer cell proliferation exists in the literature, the molecular and cellular signaling mechanisms involved are largely undefined. In our study, significant inhibition of human choriocarcinoma JAr cell proliferation at physiological and pharmacological concentrations of melatonin was observed. 2‐Iodomelatonin, a high affinity melatonin receptor agonist, was more potent than melatonin in inhibiting JAr cell proliferation. In addition, the presence of putative melatonin receptors in choriocarcinoma was suggested by the demonstration of specific 2‐[125I]iodomelatonin binding to the tumor. Interestingly, the selective MT2 melatonin receptor ligand, 4‐phenyl‐2‐propionamidotetraline (4‐P‐PDOT), was found to exert not only concentration‐dependent anti‐proliferative actions on JAr cells, but also additive effects with melatonin in inhibiting JAr cell proliferation. Furthermore, MT2 melatonin receptor gene expression by JAr cells was demonstrated by reverse transcription‐polymerase chain reaction (RT‐PCR) and in situ hybridization (ISH). Taken together, our data suggest that the reported anti‐proliferative action of melatonin on human choriocarcinoma JAr cells may be mediated, in part, by MT2 melatonin receptor. Moreover, analysis of melatonin effect on cell cycle kinetics indicated that G1/S transition delay may underlie the observed inhibition of choriocarcinoma cell proliferation by melatonin.
Alzheimer β protein mediated oxidative damage of mitochondrial DNA: Prevention by melatonin
Authors: Pappolla M. A. , Chyan Y.‐J. , Poeggeler B. , Bozner P. , Ghiso J. , LeDoux S. P. , Wilson G. L.
Published: February 2007

Abstract: Most contemporary progress in Alzheimer's disease (AD) stems from the study of a 42–43 amino acid peptide, called the amyloid beta protein (Aβ), as the main neuropathologic marker of the disorder. It has been demonstrated that Aβ has neurotoxic properties and that such effects are mediated by free‐radicals. Exposure of neuronal cells to Aβ results in a spectrum of oxidative lesions that are profoundly harmful to neuronal homeostasis. We had previously shown that Aβ25 35 induces oxidative damage to mitochondrial DNA (mtDNA) and that this modality of injury is prevented by melatonin. Because Aβ25‐35 does not occur in AD and because the mode of toxicity by Aβ25‐35 may be different from that of Aβ1‐42 (the physiologically relevant form of Aβ), we extended our initial observations to determine whether oxidative damage to mtDNA could also be induced by Aβ1‐42 and whether this type of injury is prevented by melatonin. Exposure of human neuroblastoma cells to Aβ1‐42 resulted in marked oxidative damage to mtDNA as determined by a quantitative polymerase chain reaction method. Addition of melatonin to cell cultures along with Aβ completely prevented the damage. This study supports previous findings with Aβ25‐35, including a causative role for Aβ in the mitochondrial oxidative lesions present in AD brains. Most important, the data confirms the neuroprotective role of melatonin in Aβ‐mediated oxidative injury. Because melatonin also inhibits amyloid aggregation, lacks toxicity, and efficiently crosses the blood‐brain barrier, this hormone appears superior to other available antioxidants as a candidate for pharmacologic intervention in AD.
Observation of Toughness Improvement of the Hydroxyapatite Bioceramics Densified Using High‐Frequency Induction Heat Sintering
Authors: Khalil Khalil Abdelrazek , Kim Hak Yong , Kim Sug Won , Kim Kwan Woo
Published: February 2007

A novel nanocomposite has been introduced to improve the fracture toughness of hydroxyapatite (HAp) bioceramics. Composites of HAp/NiO with 1–5 wt% of electrospun NiO nanofibers were developed and studied. The mixtures were consolidated very rapidly to full density by high‐frequency induction heat sintering (HFIHS). The role of NiO nanofibers in enhancing the toughness, hardness, and microstructure properties of the HAp bioceramic was investigated. Field emission scanning electron microscopy was used to examine the morphology of the bioceramic composites and fracture surfaces to reveal the dominant toughening mechanisms. The results showed that the sintering behaviors, toughness, and hardness of the resulting composites were significantly enhanced by the inclusion of NiO nanofibers. The fracture toughness of the heat sintered HAp/NiO electrospun nanofiber composites was 1.8 times higher, as the concentration of NiO electrospun nanofibers reached 5 wt%.
ENERGY CONSUMPTION FOR REFRIGERATED, CANNED, AND FROZEN SNAP BEANS AND CORN
Authors: RAO M. ANANDHA
Published: February 2007

The energy inputs at different stages in the food cycle of corn and snap beans were estimated for refrigerated, canned, and frozen market forms. In the case of corn, the energy inputs totalled 3,146, 2,986,and3,902Btu/2.9oz serving for canned, frozen, and refrigerated market forms. The corresponding figures (Btu/2.3oz serving) for snap beans were2,913, 2,715,and2,134,respectively. The difference between the magnitudes for the canned and frozen forms is not significant. Further, because of the variability in the energy data for the different stages in the food cycle, magnitudes of energy consumption different than those listed may be obtained. The present and earlier studies on vegetables show that edible yield (number of servings) plays a major role in the energy consumed in the total cycle. Based on the present and previously published studies on energy consumption for vegetables, it appears that raw or refrigerated vegetables with yields more than about40%will require less energy than other market forms. In this context, while most raw vegetables have yields higher than40% they have short storage lives. Therefore, a large number of vegetables must be frozen or canned for long term availability.
RETORT POUCH: THE DEVELOPMENT OF A BASIC PACKAGING CONCEPT IN TODAY'S HIGH TECHNOLOGY ERA1
Authors: LAMPI RAUNO A.
Published: February 2007

One indication of progress and maturity for a technological concept is that, in any introduction to discussion on the subject, descriptive details, characteristics, and founding principles can be minimized. The retort pouch is a multi‐layer polymer‐foil pouch used (Fig. 1) in lieu of the metal can or glass jar for shelf‐stable foods or refrigerated or frozen foods. Although, from technological and commercial acceptance aspects, the retort pouch's applicability should be judged alone without comparison, the comparison with cans for preservation mode, frozen “boil‐in‐bag” items for end product utility, and to both for the cost‐value relationship is inevitable.
RETENTION OF FREE FATTY ACIDS DURING SPRAY DRYING OF CHEDDAR CHEESE
Authors: AMUNDSON C. H. , ISHINO K. , LINDSAY R. C.
Published: February 2007

The effect of processing variables, such as total solids, atomization pressure and inlet drying air temperature, on the retention of free fatty acids (FFA) in Cheddar cheese during spray drying was investigated. A cheese homogenate was prepared with minimum heat treatment and spray dried at a feed temperature of approximately 43°C. The retention of FFA increased with molecular weight under all drying conditions. In the absence of emulsifying salts, a lower total solids content in the homogenate fed to the dryer increased the retention of FFA. For example, the maximum retention of butyric acid at 30% T.S. and at 4% T.S. was about 60% and 35%, respectively. In addition, higher atomization pressures and higher inlet drying air temperatures decreased the retention of FFA. Emulsifying salts were effective, especially at 40% T.S., in increasing the retention of FFA. These results could be predicted from the selective diffusion theory of the retention of volatile compounds.
USE OF THE BIRD‐LEIDER EQUATION IN FOOD RHEOLOGY
Authors: DICKIE ANN M. , KOKINI JOZEF L.
Published: February 2007

Shear stress development at inception of a constant shear rate was studied for marshmallow cream, peanut butter, squeeze margarine, tub margarine, whipped butter, whipped cream cheese and whipped dessert topping using the cone and plate geometry of the Rheometrics Mechanical Spectrometer. For most foods studied transient shear stresses showed increasing shear stress oversoots with increasing shear rate. At the highest shear rate of 100 s−1, transient stresses were as large as 425% of the steady state shear stresses, with the actual magnitude of overshoot depending on the particular food investigated.

The Bird‐Leider equation was chosen to model this time dependent flow behavior by incorporating both steady viscous and elastic properties of the foods. By assuming that the viscosity function and primary normal stress coefficient followed power‐law behavior, and constructing a time constant from the calculated parameters, the Bird‐Leider model provided a good prediction of maximum and steady state stresses as well as the time at which they occur, but only a crude prediction of shear stress decay. The model supplied two more empirical constants “a” and “b” where “a” can be regarded as a pseudo‐elastic modulus. Variation in “a” with shear rate shows that all materials studied are nonlinear viscoelastic.
THE EFFECT OF HEAT AND SHEAR ON THE VISCOELASTIC PROPERTIES OF SOY FLOUR DOUGH
Authors: BAIRD D. G.
Published: February 2007

This paper is concerned with the effect of heat and shear on the rheological properties of defatted soy dispersions and doughs of 30 to 60% flour by weight. Capillary and rotary rheometers (Rheometrics Mechanical Spectrometer) were used to heat doughs up to 75° C and shear them simultaneously. In one series of experiments using a modified Instron capillary rheometer the doughs were heated to several different temperatures and then sheared. The linear viscoelastic properties of the dough which were determined by means of a plate‐plate rheometer were then compared to the fresh dough and those of a heated but nonsheared dough. In another experiment a cone‐and‐plate rheometer was used to heat and shear the dough. The linear viscoelastic response of the dough was used to monitor any changes as it was heated and sheared. It was observed that only in the higher moisture dispersions (i.e., moisture contents greater than 50%) were there any signs of an increase in rheological properties which might be associated with “cooking”. It was concluded that cooking of soy flour doughs most likely does not involve the formation of a permanent network formed by covalent chemical bonds. Hence, in extrusion cooking processes involving soy flour doughs, it may not be necessary to treat the rheological properties of the dough as a thermosetting system.
THE EFFECT OF APPLE MATURITY AND FIRMNESS ON BRUISE VOLUME1
Authors: DIENER R. G. , SINGHA S. , PETIT J.
Published: February 2007

Red and Golden Delicious apples were tested to determine resistance to impact bruising with respect to day after bloom. Impact resistance measured by volume of bruised tissue was found to have a significant linear relation to day after bloom, firmness and bruise energy. Specific bruise volume (bruise volume per unit of energy input) did not change significantly over the growth period of the fruit when a constant drop height was maintained. This indicates that increases in bruising as the apple matures are due to increased weight of the fruit (bruise energy) rather than change in properties of the apple tissue.
ERROR ANALYSIS IN ESTIMATING THERMAL DIFFUSIVITY FROM HEAT PENETRATION DATA1
Authors: LARKIN JOHN W. , STEFFE JAMES F.
Published: February 2007

The ability to predict thermal diffusivity from heat penetration data containing normally distributed errors in can dimensions, measurements in time, measurements of temperature, thermocouple probe location, and assumptions concerning surface heat transfer coefficients was investigated using a nonlinear least squares solution of Fourier's heat conduction equation. Thermal diffusivity calculated from heat penetration data is largely dependent on errors associated with temperature measurement and to a lesser extent dependent on errors in thermocouple probe location. Errors in can dimensions and time measurement had only a minor influence on the prediction of thermal diffusivity. Best prediction accuracy is obtained under the following conditions: (1) When a large can with a length over diameter ratio close to 0.8 is used; (2) when the difference between the initial and heating medium temperature is greater than 40°C; (3) when the data used for calculation of thermal diffusivity is limited to the temperature ratio range of 0.15 to 0.85; (4) when the Biot Numbers for the surfaces of the can are measured or known to be greater than 200; (5) when an accurate time clock is used, and when the position of the thermocouple probe is accurately known.
APPLICABILITY OF FLOW MODELS WITH YIELD FOR TOMATO CONCENTRATES
Authors: RAO M.A. , COOLEY H.J.
Published: February 2007

Shear rate‐shear stress data on about fifty tomato concentrates were employed to study the applicability of three flow models: Herschel‐Bulkley (H‐B), Mizrahi‐Berk (M‐B), and Vocadlo. The magnitudes of the three parameters of each model were determined by means of nonlinear regression analysis. The H‐B and M‐B models described very well the flow data. The logarithm of the apparent yield stress values predicted by each model and total solids of the concentrates were related by a quadratic equation. The magnitudes of the flow behavior index of each model did not change significantly over the total solids range studied: 6–36%. The consistency index of the Vocadlo and H‐B model, and the concentration of the tomato concentrates were related by a power relationship. Over the temperature range 15–55°C, the flow behavior index of each model did not change significantly. The yield stress decreased with increase in temperature reaching a nearly constant value at 55°C. The consistency index of each model and temperature could be correlated by the Arrhenius equation.
ENERGY CONSUMPTION IN A CONCENTRATED ORANGE JUICE PLANT
Authors: FILHO J. GASPARINO , VITALI ALFREDO A. , VIEGAS FLAVIO C. P. , RAO M. A.
Published: February 2007

The consumption of electricity and thermal energy for frozen concentrated orange juice (FCOJ) and citrus pulp pellets (CPP) was determined in a plant. Thermal energy accounted for 90% of the total energy consumption in the plant and its consumption for CPP exceeded that for FCOJ. The kilocalories of thermal energy per kg of water evaporated (KKWE) in the evaporators increased as the feed rate of single strength juice was decreased. At the design evaporation capacity, the steam efficiency of two tubular evaporators and two plate evaporators was found to be 0.85N and 0.82N, respectively; N being the number of effects of the evaporator. Fouling of the waste heat evaporator was a major reason for the high energy consumption in the CPP unit.
A REVIEW of FUNDAMENTAL PROCESS ASPECTS FOR the PRODUCTION of MUSHROOM MYCELIUM
Authors: MARTIN ANTONIO M.
Published: February 2007

A review of fundamental process aspects to produce mushroom mycelium in submerged culture is presented. With peat hydrolysate as the main nutrient source, the operations of substrate preparation, cultivation and product recovery are explained. Based on the growth of Agaricus spp. mushroom mycelium, the conditions for the production of the desired mycelial pellets are analyzed.
AUTOMATIC CONTROL of MOISTURE IN FOOD EXTRUDERS1
Authors: LEVINE LEON , SYMES STEVEN , WEIMER JOHN
Published: February 2007

A computer simulation illustrating the possibility of extrudate moisture control via feedback of die pressure is described. the simulation of a controller, utilizing dead‐time compensation, illustrates the advantages of such a control strategy. the sensitivity of the dead‐time compensating controller performance to errors in parameter estimation is examined and discussed. This type of predictive control is found to provide a stable control strategy even with very large modeling errors. Such a control system is readily implemented with a microprocessor.
WATER ABSORPTION IN CEREAL GRAINS and ITS EFFECT ON THEIR RUPTURE STRESS1
Authors: ITUEN E. U. U. , MITTAL J. P. , ADEOTI J. S.
Published: February 2007

A study on water absorption characteristics of the selected cereal grains was conducted. It was found that well dried maize, sorghum and millet grains take about 96, 48 and 24 h, respectively, to reach their water absorption capacities (water absorption saturations). Millet had the highest rate of water absorption as well as the total water absorbed. The rate of water absorption in sorghum was higher than in maize but maize grains imbibed more water than sorghum.

Rupture stress of the grains and its variation with moisture content was also investigated. The rupture stress of the grains was seen to decrease with increase in moisture content except for maize which showed a rapid rise only at the onset of the increase in moisture content.
MOISTURE TRANSFER PROPERTIES of WILD RICE
Authors: GENCTURK M. B. , BAKSHI A. S. , HONG Y. C. , LABUZA T. P.
Published: February 2007

Working isotherms for processed wild rice and desorption isotherms for unprocessed wild rice were determined at temperatures ranging from 10 to 43.5°C. the constants for the Guggenheim‐Anderson‐DeBoer (GAB), Day and Nelson, Chen and Clayton and modified Halsey equations were determined by using a nonlinear optimization technique. the GAB equation showed extremely good fit to the experimental data (less than 5% error). the diffusion coefficients for moisture transport in both broken and whole processed wild rice and for unprocessed wild rice samples were determined at room temperature. the processed broken wild rice kernels had an effective diffusion coefficient of 2.66 × 10−9 m2/h, whereas the effective diffusion coefficient was 7.08 × 10−10m2/h for the processed whole wild rice kernels. Unprocessed wild rice had moderate effective diffusivity (1.4 × 10−9 m2/h). These results predicted quite well the equilibrium water activities and time to equilibrium of wild rice‐white rice mixtures using both analytical methods and the finite element method. the transfer of moisture to or from packaged wild rice was also illustrated for different distribution systems.
ESTIMATION of HEAT of MOISTURE SORPTION and IMPROVED CRITERIA FOR EVALUATING MOISTURE SORPTION ISOTHERM EQUATIONS FOR FOODS
Authors: BALABAN MURAT O. , ZURITZ CARLOS A. , SINGH R. PAUL , HAYAKAWA KAN‐ICHI
Published: February 2007

Heat of sorption of moisture on foods can be estimated from sorption isotherm equations having both moisture and temperature as independent variables. Sorption thermodynamics dictate that the heat of moisture sorption should decrease with increased moisture concentration, or increased temperature of food, provided no biological, chemical or other changes occur during sorption. This fact, and the Clausius‐Clapeyron equation were used to derive two analytical formulae to evaluate the reliability of moisture sorption equations in the calculation of heat of sorption. As examples, Chung and Pfost, modified Harkins and Jura, modified Henderson, and Guggenheim‐Anderson‐De Boer equations at specified conditions were analyzed.
MODELLING of TEMPERATURE HISTORIES DURING VENTING of STILL RETORTS
Authors: del VALLE CARLOS ENRIQUE , SOULE CARLOS LUCIO
Published: February 2007

Experimental tests were carried on a pilot retort to gather information on the temperature evolution inside batch retorts during the venting stage. to fit the coming‐up curves the equation for the response of an over‐damped second‐order system to a step input was proposed. the parameters that characterize this equation were related to steam flow, initial temperature and retort load. Results allow the prediction of coming‐up curves for different operating conditions.
CRYOGENIC SEPARATION of CITRUS FRUIT INTO INDIVIDUAL JUICE SACS
Authors: WATANABE HISAHIKO , HAGURA YOSHIO , ISHKAWA MASANOBU , SAKAI YOSHIO
Published: February 2007

Citrus fruits were crushed by a falling ball type impact crusher at low temperature and their juice sacs were separated into individual sacs. the effect of freezing temperature on the degree of separation was examined, using four kinds of citrus fruits, Unshu orange, sweet orange, grapefruit, and lemon. the results indicated that the degree of separation depended solely on temperature regardless of sample size, applied force, and fruit kind. No shattering occurred above ‐ 30°C. the degree of separation increased until below − 120°C, there was little further separation. the cause of no shattering at or above − 30°C was attributable to the mechanical property of juice.
REVERSE OSMOSIS CONCENTRATION of APPLE JUICE: FLUX and FLAVOR RETENTION BY CELLULOSE ACETATE and POLYAMIDE MEMBRANES
Authors: CHUA HUNTER T. , RAO M.A. , ACREE T.E. , CUNNINGHAM D.G.
Published: February 2007

Apple juice was concentrated in a pilot scale reverse osmosis unit using two commercial spiral wound cellulose acetate membranes with 97% (CA‐97) and 99% (CA‐99) NaCl rejection ratings and an experimental polyamide (PA‐99) membrane with 99% salt rejection rating. Flux and concentration rates were higher for the PA‐99 membrane than for the CA membranes. Gas chromatographic analysis of feed, permeate, and concentrate samples was undertaken and a mass balance of odor‐active volatiles was performed. the PA‐99 membrane retained 45% of the total odor‐active volatiles while the CA‐99 retained 23 %. Acetates were not found to increase when apple juice was concentrated with the cellulose acetate membrane. Retention of individual aroma compounds for the CA‐99 and PA‐99 membrane was rationalized using polar, nonpolar, and steric parameters.
MODELING of VENTING TIME, TEMPERATURE DISTRIBUTION and STEAM CONSUMPTION DURING VENTING of RETORTS
Authors: del VALLE C. E. , SOULE C. L.
Published: February 2007

A model to predict the temperature history of the slowest heating point during venting of steam retorts is proposed. the theoretical analysis was based on a physical interpretation of the system behavior. the model was used to evaluate the influence of steam flow rate and initial temperature on venting time, steam consumption and temperature distribution in a pilot scale horizontal retort.
THERMAL CONDUCTIVITY of CONCENTRATED WHOLE MILK
Authors: MORE G. R. , PRASAD SURESH
Published: February 2007

The information of thermal conductivity of milk is required for the design of heat exchanger equipment in the dairy processing. Thermal conductivity of whole milk was experimentally determined by a steady‐state, parallel disk, relative method at various concentrations (from 37 to 72.4% total solids) and temperature range between 40 to 90°C. This thermal property of milk increased with rise in temperature and decreased with increase in total solids content and its values varied from 0.278 to 0.491 W/m K. an expression has been proposed for derivation of milk thermal conductivity from temperature and total solids content.
CONDUCTION HEATING of HIGH MOISTURE ROUGH RICE I. THERMAL INACTIVATION of FUNGI
Authors: REYES V. G. , JINDAL V. K.
Published: February 2007

Conduction heating of high moisture rough rice was evaluated as a means of arresting fungal growth using an experimental batch‐type rotary heating unit. the heat treatments significantly reduced fungal activity in rough rice as measured by dilution plating and carbon dioxide production. the effectiveness of heat treatments depended upon the exposure time and heating surface temperature. Exposure times for isothermal heating of rough rice were determined for inactivating the fungi to specified mortality levels based on the heating surface temperature. Subsequently, a general procedure which accounted for the heating lags was developed for estimating the heat dosages based on the time‐temperature history of the bulk grain during conduction heating in any given equipment.
THE ROAST: NONLINEAR MODELING and SIMULATION
Authors: TOWNSEND M.A. , GUPTA S. , PITTS W.H.
Published: February 2007

Roasting meat is modeled as a nonlinear variable‐property heat transfer. the results are compared with conventional recommendations, and quite a variance is found for roasts which are either long or flat. the effects of initial temperature, aftercooking, and other parameters are evaluated. A companion paper considers optimizing the roasting process for a specified desired doneness profile.
BACK EXTRUSION and SIMULATION of VISCOSITY DEVELOPMENT DURING STARCH GELATINIZATION
Authors: DOLAN K.D. , STEFFE J.F. , MORGAN R.G.
Published: February 2007

A generalized apriori theoretical model relating apparent viscosity of protein dough to several independent variables was used to model gelatinized starch dispersions. Independent variables in the original model were shear rate, temperature, moisture content, temperature‐time history and strain history. the model is applied here to corn starch dispersions gelatinized using various temperature‐time treatments. Apparent viscosity of a 13.7% gelatinized cornstarch solution at constant shear rate and strain history was measured at 20 C using a back extrusion technique. Activation energy of gelatinization was estimated as 210 kJ/mol (50 kcal/mol) over the range 81–95 C. the activation energy decreased in the range 95–105 C.
RHEOLOGICAL MODELING of POTATO FLOUR DURING EXTRUSION COOKING
Authors: MACKEY KEVIN L. , OFOLI ROBERT Y. , MORGAN RON G. , STEFFE JAMES F.
Published: February 2007

A generalized model for predicting the effects of shear rate, temperature, moisture content, time‐temperature history and strain history on viscosity has been evaluated for extruded potato flour doughs. an Instron Capillary Rheometer and a 50 mm Baker Perkins co‐rotating twin screw extruder were used to evaluate all effects incorporated in the model, except strain history. the power law model was used to describe shear rate effects in the range 10–10000 s−1. the generalized model fit observed data for temperatures of 25–95°C and moisture contents ranging from 22 to 50%, wet basis. Since potato flour by its manufacturing process is pregelatinized, it was unnecessary to evaluate the effects of time‐temperature history. Strain history was found to have an insignificant influence on the viscosity.
THE COMPACTION PROPERTIES of DEHYDRATED POTATO
Authors: FERDINAND J.M. , KIRBY A.R. , SMITH A.C.
Published: February 2007

The compaction behavior of two dehydrated potato granule materials has been studied in a cylindrical geometry. the effect of moisture content and the addition of dehydrated potato flake and potato starches has also been considered. the coefficient of friction and the stress anisotropy factor have been calculated from the pressure transmission measurements using a semi‐particulate analysis previously used for polymer powders. the two granule types behaved more similarly under those conditions than their Brabender consistencies implied. the stress anisotropy factor tended to unity with increasing moisture content. the presence of other potato materials had a considerable effect on the compaction of the granules. These results indicate that the performance of processes that involve compaction of these materials, such as extrusion, will vary considerably with composition and moisture content.
HEAT TRANSFER DURING EVAPORATION of MILK to HIGH SOLIDS IN THIN FILM SCRAPED SURFACE HEAT EXCHANGER
Authors: DODEJA A. K. , SARMA S. C. , ABICHANDANI H.
Published: February 2007

Thermal performance of thin film scraped surface heat exchanger was evaluated for concentration of milk to high solids with process variables such as mass flow rate, steam condensing, temperature, etc. Appropriate dimensionless groups were formulated and fitted in Cobb‐Douglas model to obtain a correlation. This relationship which is in the form of a Nusselt equation will be useful in predicting the scraped film coefficient during milk concentration to high solids. the effect of process variables on scraped film coefficient were discussed.
MULTIRESPONSE OPTIMIZATION of ACID CASEIN PRODUCTION
Authors: FICHTALI J. , VAN DE VOORT F. R. , KHURI A. I.
Published: February 2007

A multivariate skimmilk extrusion process, designed to produce an acid coprecipitate was studied in terms of minimizing residual lactose, ash and fines. an experimental model system was utilized to simulate the extrusion process and evaluated using response surface methodology to assess the relationship between the responses (fines, residual lactose and minerals) and the process variables (concentration, pH, temperature, agitation, washing time and wash water ratio). Compromise optimum conditions were derived using the Generalized Distance Approach (GDA) and an Extended Response Surface Procedure (ERSP) which made use of the SAS RSREG procedure with and without constraints. the GDA procedure produced good results in terms of providing an optimum for a general acid casein process, while the ERSP allowed more extensive analysis of the data in terms of assessing specific processing conditions. Although more computing intensive, the ERSP conferred additional flexibility in determining optimal conditions for special situations such as extrusion processing. Both approaches are useful for process engineering, with the GDA being a more general tool while the ERSP is advantageous when the GDA procedure becomes limiting.
MODELLING of LAMINAR HEAT TRANSFER IN SCRAPED SURFACE HEAT EXCHANGERS
Authors: HÄRRÖD MAGNUS
Published: February 2007

Heat transfer experiments with starch pastes have been performed in pilot plant scraped surface heat exchangers (SSHE). Effects of the following variables were considered in the modelling of the laminar heat transfer: rotational speed; viscosity, flow rate, number of blades, radius ratio and heat transfer direction.

The poor radial mixing restricted the heat transfer coefficients. When the radius ratio increased, the heat transfer rate increased. This was probably due to increasing mixing effects from the blades. the flow rate and the heat transfer directions did not affect the heat transfer coefficients.

The scatter in the heat transfer coefficients was considerable, due to unstable flow conditions in the SSHEs. However, the scatter was reduced, compared with previous investigations, by the use of a static mixer after the SSHEs, since the radial temperature differences were eliminated.

Better design of rotor and blades may improve the performance of SSHEs operating with laminar flow.
MODELLING of VORTICAL HEAT TRANSFER IN SCRAPED SURFACE HEAT EXCHANGERS
Authors: HÄRRÖD MAGNUS
Published: February 2007

Heat transfer experiments have been performed in pilot plant scraped surface heat exchangers, using starch pastes and water as model products. When the flow was vortical, the backmixing effects were considered using the plug flow and axial dispersion model; the true surface heat transfer coefficients and axial dispersion coefficients were determined from temperature measurements. These coefficients were modelled and the following variables were considered: rotational speed, viscosity, flow rate, number of blades, radius ratio and heat transfer direction. Using these models, the overall heat transfer coefficients and the axial temperature profiles can be predicted quite precisely for SSHEs over a wide range of operating conditions. the first blade improved the heat transfer coefficients while additional blades did not; and heat transfer was higher when the radius ratio was 0.5 than when it was 0.75. the differences between previously proposed models are explained.

The most favorable flow pattern in SSHEs occurred when the flow was vortical, but close to the transition point to laminar flow.
SPECIFIC HEAT of INDIAN UNLEAVENED FLAT BREAD (CHAPATI) AT VARIOUS STAGES of COOKING
Authors: GUPTA T. R.
Published: February 2007

A simple inexpensive calorimeter was built to measure specific heat of foods at various process temperatures. By using vegetable/mineral oil as the heating medium in place of water, specific heat at temperatures beyond 100°C can also be evaluated. Specific heat of whole wheat dough and Chapati (round disc prepared mostly from whole wheat flour dough) at various stages of cooking and puffing were determined. Based on the experimental data a linear equation (C = 2476.56 + 23.56M − 3.79Te) is proposed from the experimental data for specific heat of wheat flour, dough, cooked and puffed Chapati and for other food materials at moisture levels ranging from 0.1% to 80% and temperature ranges from 303° to 336° K.
THERMAL PROCESS TIME CALCULATIONS FOR THIN PROFILE PACKAGES: COMPARISON of FORMULA METHODS
Authors: GHAZALA S. , RAMASWAMY H.S. , SMITH J. , SIMPSON B.
Published: February 2007

The process time calculation accuracy of five formula methods were evaluated in relation to predictions from a computer model based on finite difference numerical solution to three‐dimensional heat conduction equations with finite surface convection as applicable to processing of packaged foods in thin profile forms. Heat penetration data were obtained from the computer model for a range of package sizes, food properties and processing conditions. the centerpoint time‐temperature data were used to calculate process times required for a target lethality of 5.0 min using the General method approach (employing numerical integration). the study indicated that process time prediction errors for the different methods calculated as percent deviations from those computed using the General method were relatively small (below 4% on average) within the range of experimental conditions.
A ONE‐DIMENSIONAL STRESS PULSE PROPAGATION MODEL FOR CRYO‐COMMINUTION of AGGLOMERATED GRANULES INTO INDIVIDUAL GRANULES
Authors: WATANABE HISAHIKO , SAKAI YOSHIO
Published: February 2007

An elementary theory of stress pulse propagation was applied to a one‐dimensional mathematical model for cryo‐comminution of agglomerated granules into individual granules. an assembly of granules is approximated by a bar constructed with blocks stuck together. When an impulsive loading is given at one end of the bar, a compressive stress pulse generates there and propagates through the bar. When it survives after transmitting through the interfaces between blocks and reaches the opposite free end, the compressive stress pulse turns into a tensile stress. This tensile stress causes separation of the block located farthest away from the loading end, provided the intensity of the stress pulse exceeds the tensile strength of the material. the model successfully explained the experiment on shattering orange juice ice as well as frozen citrus fruit.
ASSESSMENT of A SEMI‐EMPIRICAL FOUR PARAMETER GENERAL MODEL FOR SIGMOID MOISTURE SORPTION ISOTHERMS1
Authors: PELEG MICHA
Published: February 2007

Published sigmoid moisture sorption isotherms (0 < aw < ∼ 0.9) were fitted by the four parameter models m = k1awn1+ k2awn2 where m is the moisture contents (dry basis), aw the water activity and the k and n values are constants (n1 < 1 and n2 > 1). Not surprisingly, the model had the same or better fit than the GAB model. In contrast with both the BET and GAB models, the proposed model is not based on the assumption that there exists a well‐defined monolayer of absorbed water. At aw < ∼ 0.4 and n1 > ∼ 0.55, however, the model produces a practically linear aw/[m(1 – aw)] vs aw plot, of the kind used to calculate the monolayer moisture with the BET model.

The proposed model can be a convenient means to catalog both sigmoid and nonsigmoid isotherms, and used to calculate the equilibrium water activity of dry mixtures with equations solving software.
ANALYSIS of the HELICAL SCREW RHEOMETER FOR FLUID FOOD
Authors: TAMURA MAGDALENA S. , HENDERSON JERALD M. , POWELL ROBERT L. , SHOEMAKER CHARLES F.
Published: February 2007

The Helical Screw Rheometer (HSR) is being evaluated for rheological measurements of fluid food suspensions. the HSR consists of a helical screw enclosed in a tight fitting cylinder. With a closed system the inner screw is rotated creating a linearly increasing pressure differential along the axis of the screw, which is proportional to the viscosity of the fluid. This paper presents theoretical one‐ and two‐dimensional flow analyses for Newtonian fluids using both rectangular and cylindrical coordinates. For non‐Newtonian fluids a one‐dimensional rectangular analysis was developed using the power law model.
A GRID GENERATION TECHNIQUE FOR NUMERICAL MODELLING HEAT and MOISTURE MOVEMENT IN PEAKED BULKS of GRAIN
Authors: SINGH A.K. , THORPE G.R.
Published: February 2007

This paper describes a numerical solution procedure to study heat and moisture transfer processes by two‐dimensional natural convection phenomena in grain stores with arbitrary geometries. This enables grain storage technologists to investigate the design and performance of grain stores in which the grain surface is peaked, as in bunker storage, for example. Momentum transfer is described by an elliptic partial differential equation, which governs the behavior of the stream function. Using an algebraic grid generation technique, the governing equations are transformed into a body‐fitted rectangular coordinate system that allows coincidence of all boundary lines with a coordinate line. Numerical solutions of the resulting equations are obtained using an alternating direction implicit method. Results from numerical experiments on a peaked bulk of stored grain retained between two vertical walls are obtained that show the magnitude and directions of convection currents and contours of temperature, moisture, dry matter loss and chemical pesticide concentrations.
TIME‐VARIABLE RETORT TEMPERATURE PROFILES FOR CYLINDRICAL CANS: BATCH PROCESS TIME, ENERGY CONSUMPTION, and QUALITY RETENTION MODEL1
Authors: ALMONACID‐MERINO SERGIO F. , SIMPSON RICARDO , TORRES J. ANTONIO
Published: February 2007

The batch retort model developed uses a heat transfer equation for heat conduction in cylindrical cans, first order kinetics for microbial inactivation, first order kinetics for quality losses and a transient energy balance to estimate steam consumption. For a given retort, lethality process and quality retention, the transient energy balance equation in the model allowed the identification of feasible time‐temperature profiles reducing energy consumption, total process time or both. In the examples analyzed and depending upon product specifications, time‐variable retort temperatures reduced process time by 18–55 min. These examples suggested that a change from constant to time‐variable retort temperatures could increase canning capacity by 20–50%.
THE RHEOLOGICAL PROPERTIES of RICE GRAIN
Authors: CHATTOPADHYAY P.K. , HAMANN D.D.
Published: February 2007

For rice kernels uniaxial compressive modulus function, the time‐temperature and time‐moisture content shift factors, the bulk compressive creep modulus, the uniaxial compressive stress relaxation modulus, and the uniaxial compressive failure stress were experimentally determined, while the shear modulus and Poisson's ratio were calculated from the available experimental data.

Uniaxial compression tests were carried out at deformation rates of 0.254.0.0508 and 0.0127 cm per min for five temperatures in 11C increments from 25 to 69C for each of the four moisture levels of 12, 17, 22 and 29% (d.b.). Stress relaxation and bulk compression tests were performed at the same four moisture levels and at the temperature of 25C.

Master curves for uniaxial compressive modulus and failure strength were developed as functions of reduced time where the temperature and moisture effects were transformed to equivalent time effects by the method of reduced variables. the brown rice kernel was found to have only one time‐temperature and one time‐moisture shift function showing that the material is thermo‐ and hydro‐rheologically simple.
MOISTURE SORPTION STUDY ON NIGERIAN FOODS: MAIZE and SORGHUM
Authors: SOPADE P.A. , AJISEGIRI E.S.
Published: February 2007

Adsorption‐desorption behavior of maize and sorghum between aw= 0.10–0.98 at temperatures of 20, 25 and 40C was studied. the grains exhibited type II sorption isotherm. the sorption data were analyzed using six sorption models and the coefficients of determination were between 0.6965–0.9994. the Caurie model gave the poorest fit and the Henderson model the best. Some models were better for adsorption than for desorption. the GAB and BET monolayer moisture contents were not significantly (p > 0.05) different. Monolayer values were temperature‐dependent with activation energy from 1.36–10.08 MJ/mol and the maize monolayer values exhibited the highest sensitivity to temperature. Heat of sorption was obtained by applying Claussius‐Clapeyron equation to the sorption isotherms at the three temperatures. the heat of sorption decreased with an increase in moisture content and an exponential equation was used to describe the relationship. the processing and storage consequences of this information were discussed.
DENSITY of FRESH and FROZEN SEAFOOD
Authors: RAHMAN MD. SHAFIUR , DRISCOLL R.H.
Published: February 2007

The apparent density varied from 1042 to 1093 kg/m3 and 972 to 1017 kg/m3 for fresh seafood at 20C and frozen seafood at ‐30C, respectively. the apparent density of frozen squid mantle meat decreased from 1062 to 990 kg/m3 when temperature varied from ‐1.5 to ‐40C.
ELECTRODIALYSIS of WHEY PERMEATES and RETENTATES OBTAINED BY ULTRAFILTRATION
Authors: PÉREZ A. , ANDRÉS L.J. , ÁLVAREZ R. , COCA J. , HILL C.G.
Published: February 2007

Demineralization of a synthetic UF‐whey permeate and a reconstituted UF‐whey retentate was studied in a laboratory electrodialysis (ED) unit.

Data on conductivity, ionic concentration, ash removal, electrical efficiency and energy consumption are reported at three temperatures (20, 35 and 45C) and three flow rates (100, 160 and 230 l/h). the extent of deashing is lower for the UF‐whey retentate than for the UF‐whey permeate as a result of concentration polarization, which results in an increase of the boundary layer thickness, due to deposition of proteins and salts on the membranes.
DETERMINATION of CONVECTIVE HEAT TRANSFER COEFFICIENT BETWEEN FLUID and CUBIC PARTICLES IN CONTINUOUS TUBE FLOW USING NONINVASIVE EXPERIMENTAL TECHNIQUES1
Authors: ZITOUN KHALED B. , SASTRY SUDHIR K.
Published: February 2007

Convective heat transfer coefficients (hfp) between fluids and cubic particles in continuous flow were investigated with respect to flow rate, viscosity, particle size, and radial location using noninvasive methods: (1) liquid crystal color change, and (2) measurements of relative velocity via flow visualization (for verification of liquid crystal results). All tests were conducted using sodium carboxymethyl cellulose (CMC) as the carrier fluid. Results indicate that hfp increases with decreasing particle size, increasing flow rates and (as expected) decreasing viscosity. Radial location affects hfp values: changing the particle position from the center to the bottom of the tube increases the convective heat transfer coefficient. Comparison between the methods indicates good agreement, providing a means of verification for the liquid crystal method.
COMPARISON of TWO OPERATING METHODS of A PLATE HEAT EXCHANGER UNDER CONSTANT HEAT FLUX CONDITION and THEIR EFFECT ON the TEMPERATURE PROFILE DURING MILK FOULING
Authors: YOON JUNGRO , LUND DARYL B.
Published: February 2007

Two methods of operating a plate heat exchanger under constant heat flux were studied: Method A) control by increasing the flow rate of the heating medium; and Method B) control by increasing the inlet temperature of the heating medium. the cross‐sectional temperature variation in the plate used in this study was smaller than that of an intermating‐type plate. A change in the axial temperature profile was discovered as a result of the uneven formation of milk deposit along the channel. the temperature changes of both the milk and the solid‐milk interface (stainless steel‐milk or deposit‐milk) during fouling were larger when the effects of fouling were overcome by increased flow rate of heating medium than when the effects of fouling were overcome by increased temperature of the heating medium. A quadratic empirical model underpredicted the temperatures in the lightly fouled region and overpredicted the temperatures in the heavily fouled region.