Papers by KENNETH SWARTZEL
HEAT TREATMENT | Ultra-high Temperature (UHT) Treatments
Encyclopedia of Food Sciences and Nutrition, 2003
Computerized specification of a unified model for the heat transfer processes that occur during canning, SSHE and electrical resistance aseptic processing of food products with large particles resistance aseptic processing of food products with large particles
North Carolina State University. Dept. of Statistics, 1992
Thermal memory cell and thermal system evaluation
Method and Apparatus for Pasteurizing Liquid Whole Egg Products
Uperisation de produits d'×ufs entiers liquides par chaleur directe
Journal of Food Engineering, 1993
Thermal evaluation methods for fbod processes are derived from either the Arrhenius or the Bigelo... more Thermal evaluation methods for fbod processes are derived from either the Arrhenius or the Bigelow models, among them the thermal death time method (TDTM) with z = 10°C and the equivalent point method (EPM) are of particular interest, Incorporation of a reference temperature (TKI,,) into these two methods is examined for both low-and high-temperature thermal processing. Four examples are presented, covering batch and continuous operations. For T,, =12l.II"C, the TDTMfor a typical canning operation yields a processing time 7% larger than that of the EPM; by contrast, applying the TDTM to continuous processes may result in large underestimations of the processing time, i.e. between 30 to 40% lower than those of the EPM. To avoid such underestimations, a new TKp, = 1450°C is proposed, which is obtained by setting the first derivative of the Arrhenius equation equal to l/z. In this way, the design of thermal processes can be achieved with only small overestimations or negligible underestimations. In addition, the EPM makes it possible to evaluate easily F and G values for the Bigelow and Arrhenius models, respectively.
Kinetic Compensation Effect in the Heat Denaturation of Whey Protein
Journal of Food Science, 1990
... of Food Science and Authors Jones and Swartzel are with the Dept. ... Instances of compensati... more ... of Food Science and Authors Jones and Swartzel are with the Dept. ... Instances of compensation behavior of heat denaturation of proteins have been reported (Barnes et al.,' 1969; Elizondo and Labuza, 1974; Rosenberg et al., 1974; Uden and Vidal-Leiria, 1976). ...
Rheological properties of aged ultra-high-temperature steam injected soft serve ice cream mix and melt
Journal of Dairy Science, 1980
Quality determination of aged direct steam injected ultra-high-temperature dairy products. Mathematical treatments of variations in physical properties
Dissertation Abstracts International B, 1980
Journal of Dairy Science, 1980
Fluid dairy products (fat range .5 to 10.5%) were processed in an ultra-hightemperature steam inj... more Fluid dairy products (fat range .5 to 10.5%) were processed in an ultra-hightemperature steam injection system. Time-temperature relationships of processing included 138, 143, and 149 C for 20.3 s; 143 and 149 C for 6.9 s; and 149 C for 3.4 s. Product from each treatment was stored at 4, 24, and 40 C. Absorbancy readings were at 470 and 720 nm on subsamptes at 4-wk intervals for 60 wk. Effects of light scattering were minimized by computing nA (A47o-A720). An increase in AA corresponded to change in slope of the spectrum between 470 and 720 nm, a change associated with discoloration (browning). All samples demonstrated an initial decrease in AA with an eventual increase over the storage period. Samples stored at 4 C decreased the most in aA with those at 40 C, the least. The eventual increase of zx A occurred earlier and at a greater rate as storage temperature increased. With more severe heat treatments, the initial AA's were higher. From taste panel data compiled on the same samples at the same time intervals, an empirical relationship was formulated between AA, percent fat, taste panel evaluations, and storage time. A high correlation between taste panel ratings and zxA readings was possible, suggesting an effective quality assurance test for stored ultra-high-temperature dairy products.
Effect of Temperature and Time of Processing and Storage on Consumer Acceptability of Ultra-High-Temperature Steam Injected Whole Milk
Journal of Dairy Science, 1980
Food Properties and Computer-Aided Engineering of Food Processing Systems, 1989
Two new non-isothermal methods for generating kinetic data for food constituents are examined. Th... more Two new non-isothermal methods for generating kinetic data for food constituents are examined. The first consists of a stirred batch reactor using linearly increasing temperature. The second employs a continuous flow reactor and a novel thermal evaluation method for defining the thermal treatment. The significance and implications of both methods are examined as related to each other and to classical data generation methods.
Initial whitening phenomenon of skim milk on heating
L'etude cinetique du blanchissement du lait montre que le phenomene est lie a la temperature ... more L'etude cinetique du blanchissement du lait montre que le phenomene est lie a la temperature de chauffage. Il semble mettre en cause les proteines thermolabiles solubles du lait
Kinetics studies in the colour changes of skim milk
On the use of water in the measurement of solid surface tension
Surface and Interface Analysis, 1987
Characterization of surfaces which undergo biological fluid contact is often aided by contact ang... more Characterization of surfaces which undergo biological fluid contact is often aided by contact angle analysis. A comparison of solid surface tension evaluation methods, particularly addressing a sessile drop technique including and excluding water as a diagnostic liquid, and one in which the surface itself is equilibrated with water is reported for four materials. A particular non-linear relationship between macromolecular deposition and solid surface tension has been observed in our laboratory and elsewhere. This relationship may not be predicted if surface analysis is performed outside an aqueous environment.
Journal of Texture Studies, 1981
Four commercial butters (conventional batch and Westfalia, Contimab and Cherry-Burrell continuous... more Four commercial butters (conventional batch and Westfalia, Contimab and Cherry-Burrell continuous churned) were stored at two temperatures and evaluated periodically for rheological and textural properties. Evaluation methods included four mechanical tests (quasistatic shear, quasistatic uniaxial compression, Penetrometer, and extrusion) and sensory ratings of spreadability, firmness, and other texture parameters. The first three mechanical methods produced quasistatic shear yield stress values that had close agreement. For quality control the three tests can be considered equivalent. Shear stress-strain rate data from extrusion testing developed using the Rabinowitch-Mooney equation could be represented well by the Casson model. Casson yield stress values were a n order of magnitude lower than the quasistatic values. The power law equation with a yield stress also represented the butter flow well, and all four butters had similar power law exponents (approx. 0.56). The Cherry-Burrell butter had much higher quasistatic and Casson model constants than 'Presented at the 52nd Annual Meeting of the Society of Rheology, Williamsburg, Virginia, February 23-25, 1981. Approved for publication as paper no. 7046 in the Journal Series of the North Carolina Agricultural Researah Service, Raleigh, North Carolina 27650. The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service, nor criticism of similar ones not mentioned.
Kinetics of Color Change of Grape Juice Generated using Linearly Increasing Temperature
Journal of Food Science, 1989
ABSTRACT Kinetics of the color change of grape juice was studied using linearly increasing temper... more ABSTRACT Kinetics of the color change of grape juice was studied using linearly increasing temperature for heating Noble grape juice in a stainless steel reactor. The juice was heated from 60o to 95oC in 9 hr. Kinetic parameters for the color change were determined using Hunter L, a, b-values, chroma values, and Total Color Difference (TCD) values. The reaction of the color change of grape juice measured by L- and a-values, and Chroma value followed first order kinetics with activation energies of 114.75, 131.80, and 121.21 kJ/mol and frequency factors of 1.30 × 1012, 8.95 × 1014 and 1.93 × 1013 sec−1, respectively. However, the reaction measured by TCD followed zero order kinetics with the activation energy and the frequency factor of 92.81 kJ/mol and 4.80 × 1010 mol/l/sec, respectively.
Journal of Food Science, 2003
Tap water and 1% CMC solutions were heated in a 40.68 MHz, 30 kW continuous flow radio frequency ... more Tap water and 1% CMC solutions were heated in a 40.68 MHz, 30 kW continuous flow radio frequency unit. Temperatures at different vertical and radial locations were monitored by fiber optic probes during batch heating of tap water and 1% CMC solution. Temperatures at different locations were similar during batch heating of tap water, while a significant temperature difference was observed for 1% CMC solutions, with the temperature close to the wall being higher than that at the center. Similar trends were observed during continuous heating of tap water and 1% CMC solutions, with T wall > T R/2 > T center for the latter. The observations were a result of different dielectric properties of these 2 fluids, as well as the fluid flow characteristics during continuous heating.
Journal of Food Science, 1990
A method is developed to determine time-temperature equivalencies within discrete particles durin... more A method is developed to determine time-temperature equivalencies within discrete particles during thermal processing. Encapsulated calibration materials were examined for establishing the equivalent point for a canning process where results were in good agreement with thermal evaluations using Ecklund thermocouple data. Process characteristics for continuous flow, as Reynolds number, Nussclt number, residence time distribution within heat exchangers and holding tubes, and size and shape of particles are considered for expanding the use of the methodology.
Journal of Food Science, 1990
The kinetics of sucrose (pH 2.5), Blue#2 (pH 11.3) and Blue#2 (pH 9.5) were determined for high f... more The kinetics of sucrose (pH 2.5), Blue#2 (pH 11.3) and Blue#2 (pH 9.5) were determined for high food processing temperatures. A traditional batch kinetic data generation and a novel continuous flow method were examined. The novel method consisted of a tubular flow reactor designed to establish the time-temperature equivalent points for any process. Activation energy values determined for the continuous method were 46.0, 27.2 and 52.3 kJ/mol for sucrose, Blue#2 (pH 11.3) and Blue#2'(pH 9.5), respectively. Values utilizing the traditional batch (capillary tube) generation method yielded 94.6, 58.2 and 74.5 kJ/mol, respectively. Based on these results, a new thermal evaluation technique is proposed for describing difficult to define continuous flow systems. pended in water rather than in milk. The discrepancy between the systems could not be explained although it was suggested that the fundamental difference between spore destruction in capillary tubes and spores destruction in bulk in a processing plant might be possible. Physical effects can play an important role with constituent changes or spore inactivations in a process unit. Physical effects on kinetic parameters can only be determined with the incorporation of processing stresses as described by Burton et al. (1977). If these kinetic results are to be useful to the engineer, the results must be verified in food systems subjected to actual processing conditions. Lathrop and Leung (1980) demonstrated that the kinetic data obtained from model buffer systems may not be applicable to food systems. Thompson et al. (1979) determined the kinetic parameters for degradation of available lysine in soy-based products. He stated that the buffer kinetic model would fail if the process included shear rates or if oil were added to food systems. Including these and other factors that influence reaction rates increase the complexity of the experimental study and the application. However, to effectively design, optimize and control food processes for quality and safety, a better understanding of reaction rates at high temperature food processing is desirable.
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Papers by KENNETH SWARTZEL