Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.
A one-day ration can be supplied to a soldier in the form of one ration pack for 24 hours or thre... more A one-day ration can be supplied to a soldier in the form of one ration pack for 24 hours or three packs of meal ready-to-eat, which equals one 24-hour ration. Based on the physical activity level and consequently energy requirements, there are two categories of military operations: a) normal operations, comparable to urban police work or firefighting, and b) combat operations which represent missions involving light-infantry. The aim of this study was: a) to analyse the EU market on the subject of a main course (MC) product in flexible packaging (n = 184), in the context of military use, and b) to develop thermostabilised MC aligning with modern health and nutrition recommendations for military use, i.e. protein, carbohydrate, fat, total energy intake, and essential amino acid composition. The greatest amount of ready-to-eat meals with shelf-life over one year are produced in the United Kingdom (n = 48) and most of the MC meals are preserved using freeze-drying (n = 135). While 90%...
In the canning industry, thermal preservation processes typically are designed based on Clostridi... more In the canning industry, thermal preservation processes typically are designed based on Clostridium botulinum thermal destruction kinetics. However, some bacteria can still survive, necessitating implementation of stricter timetemperature regimen for sterilization process. The aim of this study was to compare processing effectiveness at F0 (sterilization value) 8 ±1 min from the perspective of the vegetable-based product canning facility, while analyzing the inactivation, viability, and recovery of thermophilic bacteria. Four commercial products [tomato soup and rassolnik soup - acidified food (AF), and mushroom soup and pea porridge - low-acid food (LACF)] with different heat transfer characteristics (convection and conduction) were inoculated with 6.6 log10 spores/ml Geobacillus stearothermophilus LMKK 244 (reported as DSM 6790 and ATCC 10149 in other collections) and 4.810 log spores/ml Thermoanaerobacterium thermosaccharolyticum DSM 571 spore suspensions. Food samples contaminat...
Retort thermal sterilization of canned food is a technology, which allows preserving food product... more Retort thermal sterilization of canned food is a technology, which allows preserving food products by applying heat on packaged food in retorts (autoclaves) at temperatures up to 121 °C. The thermodynamics of the processes in the retort are influenced by the product stacking method in the basket and packaging material. The aims of this study were: 1) to analyse and compare temperature distribution (TD) and the slowest to heat location in the steam-air retort stacked with glass jars and with retort pouches; 2) to analyse and compare commercial product heat penetration (HP) characteristics in glass jars and retort pouches. Temperature measurements were performed with wireless thermocouples. The come-up time (heating phase) required to achieve in the retort temperature uniformity criteria of ±0.5 °C, is 28 min when the retort is stacked with glass jars, and 24 min when the retort is stacked with retort pouches. Total calculated process time (holding phase), necessary to achieve the ste...
The present study has investigated the effect of oil rich medium supplementation with polysorbate... more The present study has investigated the effect of oil rich medium supplementation with polysorbates Tween 20, 40 and 80, for the cultivation of red oleaginous yeast Rhodotorula glutinis. R. glutinis has been cultivated in yeast extract peptone glucose modified broth (mYPG) supplemented with 2 % of waste cooking rapeseed oil and three polysorbate types with 0.5 %, 1 %, 2%, 3 %, 4 %, 5 %, 6 %, 7 %, 8 %, 9 % and 10 % concentration each. Yeast biomass was measured by the thermogravimetric method at 105 °C each day during 7-day experiment. The oil rich medium supplementation with Tween 20, 40 and 80 at concentrations ranging from 2 % to 10 % significantly increased the biomass of R. glutinis. All three types of the studied polysorbates with 0.5 % and 1 % concentration, did not affect yeast growth and the dry biomass – results were similar to the control sample without polysorbate addition. Between the three types of polysorbates, Tween 20 was selected as the preferable for R. glutinis cul...
Tomato sauce production technology implies cooking at 80-95 oC. High-density polyethylene (HDPE) ... more Tomato sauce production technology implies cooking at 80-95 oC. High-density polyethylene (HDPE) packaging material is not recommended for hot-fill process, mainly because of packaging deformation under the influence of high temperature. However, condiments could be cooled and then filled in a HDPE bottle, but the secondary contamination still can occur during the filling process. The aim of the study was to find out whether cooked tomato sauce can be filled in HDPE bottles at reduced temperatures. Two commercial products were hotfilled at 65, 70 and 75 oC, and incubated at 30 oC for 12 weeks for accelerated shelf life prediction, assuming the temperature coefficient (Q10) is 2. Microbiological tests were performed after each 2 weeks. Based on target bacteria kinetic factors obtained from literature, and time-temperature data obtained during the hot-fill process, theoretical evaluation of heat treatment processing effectiveness was performed, resulting in prediction that no bacteria...
Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.
A one-day ration can be supplied to a soldier in the form of one ration pack for 24 hours or thre... more A one-day ration can be supplied to a soldier in the form of one ration pack for 24 hours or three packs of meal ready-to-eat, which equals one 24-hour ration. Based on the physical activity level and consequently energy requirements, there are two categories of military operations: a) normal operations, comparable to urban police work or firefighting, and b) combat operations which represent missions involving light-infantry. The aim of this study was: a) to analyse the EU market on the subject of a main course (MC) product in flexible packaging (n = 184), in the context of military use, and b) to develop thermostabilised MC aligning with modern health and nutrition recommendations for military use, i.e. protein, carbohydrate, fat, total energy intake, and essential amino acid composition. The greatest amount of ready-to-eat meals with shelf-life over one year are produced in the United Kingdom (n = 48) and most of the MC meals are preserved using freeze-drying (n = 135). While 90%...
In the canning industry, thermal preservation processes typically are designed based on Clostridi... more In the canning industry, thermal preservation processes typically are designed based on Clostridium botulinum thermal destruction kinetics. However, some bacteria can still survive, necessitating implementation of stricter timetemperature regimen for sterilization process. The aim of this study was to compare processing effectiveness at F0 (sterilization value) 8 ±1 min from the perspective of the vegetable-based product canning facility, while analyzing the inactivation, viability, and recovery of thermophilic bacteria. Four commercial products [tomato soup and rassolnik soup - acidified food (AF), and mushroom soup and pea porridge - low-acid food (LACF)] with different heat transfer characteristics (convection and conduction) were inoculated with 6.6 log10 spores/ml Geobacillus stearothermophilus LMKK 244 (reported as DSM 6790 and ATCC 10149 in other collections) and 4.810 log spores/ml Thermoanaerobacterium thermosaccharolyticum DSM 571 spore suspensions. Food samples contaminat...
Retort thermal sterilization of canned food is a technology, which allows preserving food product... more Retort thermal sterilization of canned food is a technology, which allows preserving food products by applying heat on packaged food in retorts (autoclaves) at temperatures up to 121 °C. The thermodynamics of the processes in the retort are influenced by the product stacking method in the basket and packaging material. The aims of this study were: 1) to analyse and compare temperature distribution (TD) and the slowest to heat location in the steam-air retort stacked with glass jars and with retort pouches; 2) to analyse and compare commercial product heat penetration (HP) characteristics in glass jars and retort pouches. Temperature measurements were performed with wireless thermocouples. The come-up time (heating phase) required to achieve in the retort temperature uniformity criteria of ±0.5 °C, is 28 min when the retort is stacked with glass jars, and 24 min when the retort is stacked with retort pouches. Total calculated process time (holding phase), necessary to achieve the ste...
The present study has investigated the effect of oil rich medium supplementation with polysorbate... more The present study has investigated the effect of oil rich medium supplementation with polysorbates Tween 20, 40 and 80, for the cultivation of red oleaginous yeast Rhodotorula glutinis. R. glutinis has been cultivated in yeast extract peptone glucose modified broth (mYPG) supplemented with 2 % of waste cooking rapeseed oil and three polysorbate types with 0.5 %, 1 %, 2%, 3 %, 4 %, 5 %, 6 %, 7 %, 8 %, 9 % and 10 % concentration each. Yeast biomass was measured by the thermogravimetric method at 105 °C each day during 7-day experiment. The oil rich medium supplementation with Tween 20, 40 and 80 at concentrations ranging from 2 % to 10 % significantly increased the biomass of R. glutinis. All three types of the studied polysorbates with 0.5 % and 1 % concentration, did not affect yeast growth and the dry biomass – results were similar to the control sample without polysorbate addition. Between the three types of polysorbates, Tween 20 was selected as the preferable for R. glutinis cul...
Tomato sauce production technology implies cooking at 80-95 oC. High-density polyethylene (HDPE) ... more Tomato sauce production technology implies cooking at 80-95 oC. High-density polyethylene (HDPE) packaging material is not recommended for hot-fill process, mainly because of packaging deformation under the influence of high temperature. However, condiments could be cooled and then filled in a HDPE bottle, but the secondary contamination still can occur during the filling process. The aim of the study was to find out whether cooked tomato sauce can be filled in HDPE bottles at reduced temperatures. Two commercial products were hotfilled at 65, 70 and 75 oC, and incubated at 30 oC for 12 weeks for accelerated shelf life prediction, assuming the temperature coefficient (Q10) is 2. Microbiological tests were performed after each 2 weeks. Based on target bacteria kinetic factors obtained from literature, and time-temperature data obtained during the hot-fill process, theoretical evaluation of heat treatment processing effectiveness was performed, resulting in prediction that no bacteria...
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