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A new transportation system is proposed recently to improve the defects of liquid transportation by tank trucks. This method is called “soft tank transportation system”; a driver installs a sac-like container (soft tank), which is made from a tarpaulin with high-pressure resistant-waterproof zippers, in a general cargo vehicle. To evaluate the quality of sterilized milk by using the soft tank transportation system, ground and marine transportation for a long distance which took about 36 h from the shipper's loading to the receiver's unloading in a high-temperature summer season (average outside temperature was 33.4 °C) were carried out. Although the difference of milk temperature before and after the delivery varied from −0.7 to +1.4 °C, there was no difference in milk quality (fat, nonfat solids, total dissolved solids, and pH) and no coliform bacteria were detected. It can be evaluated that sterilized milk was carried in keeping good conditions by soft tank transportation system. [ABSTRACT FROM AUTHOR]

Pumpable purees from purple-flesh sweetpotatoes (PFSP) were subjected to microwave heating using a 60 kW, 915 MHz continuous flow system, followed by aseptic packaging in flexible containers to obtain a shelf-stable product. Initial test runs were conducted using a 5 kW 915 MHz microwave system to measure dielectric in-line properties and examine the puree temperature profiles. The results demonstrated uniformity in heating of the puree at sterilization temperatures (>121 °C), and the dielectric constants and loss factors were within the range of published values for orange-fleshed sweetpotato purees. The pilot-scale test runs in a 60 kW microwave unit produced shelf-stable puree packages stable at room temperature. Polyphenolic content of the PFSP purees were evaluated and the results showed that while total phenolics increased (5.9%) and total monomeric anthocyanins slightly decreased (14.5%) with microwave application, antioxidant activity determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) assays did not significantly change as a result of microwave processing. Color values showed that microwave-processed samples differed from fresh puree in saturation and hue angle, but not in overall color change. PFSP purees increased in gel strength when microwave processed, packaged, and stored, but the gel could be easily disrupted into flowable purees. Overall, high-quality retention can be obtained by microwave processing and aseptic packaging of PFSP purees so that they can be used as functional food ingredients. [ABSTRACT FROM AUTHOR]

The article investigates whether hydrogen peroxide treatments would be more efficacious than traditional methods in disinfecting tomatoes with human pathogens without harming the quality of tomatoes. In tomatoes held 48 hours postinoculation, the chlorine treatment was marginally more effective than an equivalent water rinse in lessening the target bacterial population. The hot water and 1% hydrogen peroxide treatments showed reductions no greater than 1.3 logs.

Formulae for the prediction of inactivation and accumulated lethality of bacterial spores under moist heat and high pressures were derived on the basis of classic thermodynamic and kinetics principles. The capability of the model to describe the inactivation of bacterial spores was verified using 2 independent data sets corresponding to Clostridium botulinum processed at 60°C to 75°C and Bacillus stearothermophilus processed at 92°C to 110°C. Both sets included pressures between 5 × 10 Pa and 7 × 10 Pa. The equation fit explained more than 86% of the variation of the rate constant data. The developed equations establish a strong foundation on which to compare high-pressure processing treatments of different systems. This is especially useful because most systems have different transient temperature-pressure conditions. [ABSTRACT FROM AUTHOR]

BSTRACT: Dielectric properties of mashed potatoes relevant to microwave and radio-frequency (RF) pasteurization and sterilization processes were measured over 1 to 1800 MHz and 20 °C to 120 °C. Effects of moisture content (81.6% to 87.8%, wb) and salt content (0.8% to 2.8%, wb) were investigated. Dielectric loss factors and constants decreased with frequency. Dielectric loss factors increased with temperature and salt content, but dielectric constants were not significantly affected. Ionic conductivity played a dominant role at low frequencies. Power penetration depth increased with moisture content and decreased with temperature, frequency, and salt content. Regression equations were developed to relate the dielectric properties to temperature, moisture, and salt contents. [ABSTRACT FROM AUTHOR]

BSTRACT A 915-MHz Microwave-Circulated Water Combination (MCWC) heating technology was validated for a macaroni and cheese product using inoculated pack studies. Before the tests, heat resistances of a Clostridium sporogenes (PA 3679) spore crop were determined in neutral phosphate buffer and macaroni and cheese product. Trays of macaroni and cheese products were subjected to 3 processing levels: target process (F0= 2.4), under target process (F0= 1.2), and over target process (F0= 4.8). The inoculated packs were evaluated by count-reduction method and end-point method. The microbial results showed that microbial destruction resulting from MCWC heating technology matched the calculated degree of sterilization (F0 value). This study suggests that the MCWC heating technology has potential in sterilizing packaged foods. [ABSTRACT FROM AUTHOR]

The thermal stability of Bacillus licheniformis α-amylase at low moisture content was studied, based on isothermal experiments performed in a temperature range 113 to 125 °C. The thermal Inactivation was monitored by measuring the decrease in thermal denaturation enthalpy and/or the decrease in enzymic activity on pnitrophenyl-α-D-maltoheptaoside, or on starch as a substrate. Based on enthalpy readings, an enzymic system with a z-value of 10.4 °C was observed when using a relative humidity of 81% at 4 °C. A theoretical study showed that this system could be used as a Time Temperature Integrator (TTI) to monitor the safety of sterilization processes of numerous food products. [ABSTRACT FROM AUTHOR]

Presents a procedure for theoretical calculation of internal product temperatures during the in-container sterilization of foods. Product temperature determination through traditional heat penetration tests; Inverse superposition solution; Standardized dimensionless product temperature curve.

Studies the effects of storage temperature and time on some physicochemical properties of ultra high temperature (UHT)-sterilized peanut beverages. UHT processing as alternative to conventional in-container food sterilization; Homogenization and sterilization.

Determines the feasibility of membrane-sterilizing immunoglobulin G (IgG) and aseptically adding it to ultra-high temperature (UHT) products. Stability of IgG in UHT products; Concentrations of IgG at 4, 25 and 35 degrees Centigrade over five months; Thinning of milk when stored at 25 and 35 degrees Centigrade; D values for thermal destruction of IgG.

Studies the effect of high pressure on bacteriostasis to establish a sterilization method with minimal heating. Synergistic effect of high pressurization on the bacteriostatic action of sucrose fatty acid ester at low concentration; Effectivity of oscillatory pressurization in spore sterilization.

Compares characteristics of four models of Bacillus stearothermophilus spore populations in constant and dynamic sterilization temperatures. Conceptual compositions; Isothermal response equation; Estimation of rate constants; Tests of the models; Responses to specified initial conditions.

BSTRACT Optimal sterilization temperatures are defined as the processing temperatures which result in a minimum surface cook-value after achieving the desired degree of sterility. They were calculated as a function of product heating rate, surface heat transfer coefficient, initial food temperature, heating medium come-up-time, z-value for the quality factor and target Fo-value. Different one-dimensional heat transfer shapes were considered. Compared to the other variables, initial temperature and heating medium come-up-time had little influence on optimal processing temperature. Regression equations were developed relating optimal temperatures with all relevant variables. [ABSTRACT FROM AUTHOR]

BSTRACT Effects of residual air were evaluated on the heating rates of a convectionheating product processed in a continuous rotary sterilizer. Heat penetration tests were conducted in a Steritort at various reel speeds (1-10 rpm) and air overpressures (0-69.0 kPa) using 211 × 300, 300 × 407 and 603 × 700 cans containing Washington white beans in brine. Sterilization times calculated by Ball's formula method were longer for test cans processed with overpressure than those processed with no overpressure. Maximum reduction in calculated lethality for 69.0 kPa air overpressure was 15.2% for 211 × 300 and 300 × 407 experiments and 49.4% for 603 × 700 experiments. For each can size and reel speed, average process time was a linear function of overpressure. [ABSTRACT FROM AUTHOR]

Goat's milk was heat-processed under different time-temperature conditions of pasteurization and sterilization. Losses of thiamin, riboflavin, and total vitamin C in HTST, Flash, and UHT were less than that by LTLT and Autoclave. Also residual oxygen in the milk affected the loss of total vitamin C during storage. A longer shelf-life of pasteurized milk was obtained with HTST, HTST overpasteurization, and Flash process; however, there was no significant difference between UHT and Autoclave sterilized products. From the above results, HTST pasteurization was considered the best process to preserve milk quality. [ABSTRACT FROM AUTHOR]

BSTRACT Residence time distribution (RTD) of fluid and particles was measured in the holding tube of an aseptic processing system. A unique injector device instantaneously injected a large number of particles at one time without interruption of flow. A fraction collector device sampled exiting fluid at 1-sec intervals. Exiting particles at specific lapsed times from injection, were counted from those collected. RTD of fluid was determined by dye injection. RTD of fluid and particles under turbulent flow fitted a normal distribution function. Mean residence time of fluid was 0.975 times that calculated from volumetric flow rate with standard deviation ± 4.16%. Mean residence time of particles was 1.032 times that of the fluid, standard deviation was ± 4.62%. [ABSTRACT FROM AUTHOR]

Salmonella is a foodborne pathogen causing severe gastroenteritis. Three types of Maillard reaction products (MRP) generated by heat sterilization of D-glucose and L-lysine, L-histidine, and L-arginine were studied at 2 different levels of supplementation (0.5% and 1.0%) for their influence on growth and virulence of Salmonella. Two methods, namely, real-time polymerase chain reaction (RT-PCR) and a β-galactosidase gene fusion assay, were used to determine the expression of hilA, a regulatory gene for Salmonella pathogenicity. Neither the type of MRP nor their quantities up to 1.0% affected the growth rates of S. Typhimurium EE658 ( P > 0.05). When determined by β-galactosidase assay, lysine MRP in both levels of supplementation were not found to have any effect on the hilA expression compared to the control. The addition of histidine and arginine MRP to M9 media (0.5%) increased by 2-fold hilA induction and up to 6-fold at the higher level (1%) supplementation of these compounds. Although somewhat inconsistent, RT-PCR analyses of hilA expression confirmed the greater induction effect of arginine MRP on hilA compared to lysine MRP. In contrast to β-galactosidase assay results, however, lysine MRP were found to increase hilA expression compared to the control in both supplementation levels in all trials. The potential of MRP serving as a bacterial virulence modulator may be a factor to be considered in food thermal processing when assessing Salmonella risk for causing foodborne disease. [ABSTRACT FROM AUTHOR]

Hydrodynamic cavitation is the formation of gas bubbles in a fluid due to pressure fluctuations induced by mechanical means. Various high-acid (pH ≥ 4.6) fluid foods were processed in a hydrodynamic cavitation reactor to determine if commercial sterility can be achieved at reduced processing temperatures. Sporicidal properties of the process were also tested on a low-acid (pH < 4.6) fluid food. Fluid foods were pumped under pressure into a hydrodynamic cavitation reactor and subjected to 2 rotor speeds and flow rates to achieve 2 designated exit temperatures. Thermal inactivation kinetics were used to determine heat-induced lethality for all organisms. Calcium-fortified apple juice processed at 3000 and 3600 rpm rotor speeds on the reactor went through a transient temperature change from 20 to 65.6 or 76.7 °C and the total process lethality exceeded 5-log reduction of Lactobacillus plantarum and Lactobacillus sakei cells, and Zygosaccharomyces bailii cells and ascospores. Tomato juice inoculated with Bacillus coagulans spores and processed at 3000 and 3600 rpm rotor speeds endured a transient temperature from 37.8 to 93.3 or 104.4 °C with viable CFU reductions of 0.88 and 3.10 log cycles, respectively. Skim milk inoculated with Clostridium sporogenes putrefactive anaerobe 3679 spores and processed at 3000 or 3600 rpm rotor speeds endured a transient temperature from 48.9 to 104.4 or 115.6 °C with CFU reductions of 0.69 and 2.84 log cycles, respectively. Utilizing hydrodynamic cavitation to obtain minimally processed pasteurized low-acid and commercially sterilized high-acid fluid foods is possible with appropriate process considerations for different products. [ABSTRACT FROM AUTHOR]

Continuous-flow microwave heating has potential in aseptic processing of various food products, including purees from sweetpotatoes and other vegetables. Establishing the feasibility of a new processing technology for achieving commercial sterility requires evaluating microbial inactivation. This study aimed to assess the feasibility of using commercially available plastic pouches of bioindicators containing spores of Geobacillius stearothermophilus ATCC 7953 and Bacillus subtilis ATCC 35021 for evaluating the degree of microbial inactivation achieved in vegetable purees processed in a continuous-flow microwave heating unit. Sweetpotato puree seeded with the bioindicators was subjected to 3 levels of processing based on the fastest particles: undertarget process ( F0 approximately 0.65), target process ( F0 approximately 2.8), and overtarget process ( F0 approximately 10.10). After initial experiments, we found it was necessary to engineer a setup with 2 removable tubes connected to the continuous-flow microwave system to facilitate the injection of indicators into the unit without interrupting the puree flow. Using this approach, 60% of the indicators injected into the system could be recovered postprocess. Spore survival after processing, as evaluated by use of growth indicator dyes and standard plating methods, verified inactivation of the spores in sweetpotato puree. The log reduction results for B. subtilis were equivalent to the predesigned degrees of sterilization ( F0). This study presents the first report suggesting that bioindicators such as the flexible, food-grade plastic pouches can be used for microbial validation of commercial sterilization in aseptic processing of foods using a continuous-flow microwave system. [ABSTRACT FROM AUTHOR]

Continuous flow microwave sterilization is an emerging technology that has the potential to replace the conventional heating processes for viscous and pumpable food products. Dielectric properties of pumpable food products were measured by a new approach (under continuous flow conditions) at a temperature range of 20 to 130 °C and compared with those measured by the conventional approach (under static conditions). The food products chosen for this study were skim milk, green pea puree, carrot puree, and salsa con queso. Second-order polynomial correlations for the dependence of dielectric properties at 915 MHz of the food products on temperature were developed. Dielectric properties measured under static and continuous flow conditions were similar for homogeneous food products such as skim milk and vegetable puree, but they were significantly different for salsa con queso, which is a multiphase food product. The results from this study suggest that, for a multiphase product, dielectric properties measured under continuous flow conditions should be used for designing a continuous flow microwave heating system. [ABSTRACT FROM AUTHOR]

Different methods for improving texture profile and water retention of scrambled egg patties after high-pressure high-temperature (HPHT) treatment were evaluated as part of a feasibility study for the development of shelf-stable egg products. Four formulations, a basic one, 2 with xanthan gum, 1 with cheese, were compared after HPHT treatment by analyzing texture profile and degree of syneresis. The effects of water addition of 0% to 15%, 3 levels of vacuum packaging, 4 preheating rates, and 2 HPHT conditions (700 MPa/105 °C/5 min and 700 MPa/121 °C/3 min) on texture and water retention of egg patties were also compared for selected formulations. Patties reformulated with xanthan gum and cheese resulted in at least a 30% reduction in hardness, cohesiveness, and water loss. Use of low vacuum packaging in less porous patties modified with xanthan gum maintained original texture values after 700 MPa/105 °C/5 min. Addition of water into the defrosted structure increased water holding capacity and maintained hardness within its standard value after pressurization at 105 °C and 121 °C. Most texture descriptors and syneresis did not change significantly with preheating rates after HPHT treatment. Tested mechanisms for texture and water retention improvement of HPHT treated patties can contribute to meeting quality requirements not fulfilled by conventional thermal processing for the development of shelf-stable scrambled egg products. [ABSTRACT FROM AUTHOR]

BSTRACT: There is a current need for fresh-cooked-like yet shelf-stable egg products for U.S. military combat rations. Novel thermal processes based on radio frequency (RF) energy can shorten the heating time and reduce overheating. This technology was explored to produce shelf-stable egg products for combat ration development. Clostridium sporogenes (PA 3679) spores were used as a surrogate to validate the RF sterilization process to control Clostridium botulinum. Decimal reduction time (D value) of PA3679 in scrambled eggs was determined using aluminum thermal-death-time (TDT) tubes. The thermal inactivation kinetic information was then used in inoculated pack studies to validate a novel thermal process based on 27.12 MHz radio frequency (RF) pilot scale unit. Trays of scrambled eggs inoculated with PA 3679 were subjected to 3 processing levels: target process (F0 about 5.3 min), under-target process (F0 about 3.0 min), and over-target process (F0 about 9.1 min). The results of the microbial challenge study showed that microbial destruction from the RF process agreed with sterilization values calculated from time-temperature data measured at the cold spot in the treated trays. A comparison of RF- and retort-treated scrambled eggs showed significant differences in the degree of lightness ( L*) and redness ( a*). RF-processed egg was less brown compared with conventional retorted eggs. Retort treatment of fully cooked scrambled eggs had higher hardness, springiness, and smaller cohesiveness than RF -treated samples. This study suggests that RF thermal processes can produce safe, shelf-stable sterilized scrambled eggs for both military and civilian uses. [ABSTRACT FROM AUTHOR]

The article discusses the adaptation of classical technologies to new technical developments and quality requirements by food equipment manufacturers. It describes the kinds of freezers as well as the different freezing techniques. Particular focus is also given to the various forms of classical in-container sterilization such as batch in-container sterilizers and continuous in-container sterilizers.

Optimization of thermal treatments has been proven to enhance the quality of food products, especially when operated together with a validation method that confirms the safety of the processing operations. Recent developments in the understanding and application of pasteurization treatments have allowed this area to grow at a rapid rate. UK and European consumers now have a wide variety of high-quality pasteurized foods to choose from in the retail and catering markets. Food producers have used this to their advantage by converting processing operations from severe treatments such as sterilization to milder ones that can be categorized under the pasteurization umbrella. This has increased food product quality and added value to existing products. Two examples will be given, both of which utilized a novel validation method based on time-temperature integrators to provide process safety data that were difficult to obtain by alternative methods. The first was in applying a novel processing technology, ohmic heating, to produce higher-quality fruit products when compared with traditional processing methods. The second was in the production of high-quality sous vide ready meals supplied chilled or frozen to the catering sector. These developments in technology and validation have been made possible by work at CCFRA that has taken the pasteurized foods sector forward. CCFRA has been active in pasteurization research for many years and has produced industry guideline documents on, for example, pasteurization treatments and sous vide processing. Microbiological research on the growth and death of target microorganisms has been linked with processing, hygiene, and validation research, which provided the underpinning science for these guidelines. Food manufacturers work closely with CCFRA to apply their pasteurization processes in order to produce high-quality value-added products. [ABSTRACT FROM AUTHOR]

The influence of high-pressure treatment on the 3 main folate species present in orange juice was assessed under conditions similar to those used in high-pressure pasteurization and sterilization using freshly squeezed orange juice and different model orange juices. The latter were used also to determine the influence of matrix components, pH, and excess ascorbic acid. Excess ascorbate strongly protected folates against pressure and heat. Pressurization at 600 MPa and 80°C affected model juice folates synergistically, and pressure increased the formation of 5,10-methenylfolate. In fresh orange juice, components other than ascorbate additionally stabilized folates, thus pressure preservation and pressure sterilization appeared very feasible. [ABSTRACT FROM AUTHOR]