• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.480-485
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• 2015

Effects of dynamic high-pressure (DHP) treatments on microbial stability, vitamin C concentration, color, sugar content, color, and pH of strawberry juice were studied and compared with those of the conventional thermal treatment. Freshly prepared strawberry juice was thermally treated at $110^{\circ}C$ for 1 min or treated by DHP at 205 MPa and 20, 50, 60, or $70^{\circ}C$. The thermal treatment and the DHP treatments, both with and without integration with heating at $70^{\circ}C$, reduced the number of indigenous aerobic microorganisms by >6 log CFU/mL. Vitamin C concentration, color, and sugar content were higher in the DHP-treated juice than in the thermally treated juice, regardless of integration with heating. Compared to the thermal treatment, DHP treatments resulted in longer color retention and higher sugar contents in strawberry juice stored at $4^{\circ}C$ for 63 days. These results have demonstrated the potential use of DHP as a novel method for pasteurizing strawberry juice.

• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.1113-1118
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• 2017

The objective of this study was to investigate the non-thermal sterilization effect of methods such as high hydrostatic pressure (HHP) and UV-irradiation (specifically with regard to the storage stability and shelf-life of carrot juice. The microbial counts of the non-sterilized product increased from 5.51 to 7.34 log CFU/mL up to the fifth day, and then decreased to 5.46 log CFU/mL at six days. UV-irradiation was increased from 2.37 to 4.92 log CFU/mL. HHP was maintained under the 3 log CFU/mL. The pH of UV-irradiation and HHP was maintained withing the range of 6.29~6.30 and 6.20~6.22 during storage. However, the pH arising from non-sterilization decreased from 6.31 to 4.49. The color of non-sterilization changed significantly during storage, but UV-irradiation and HHP were similar during storage. The ${\beta}$-carotene content of non-sterilization was noted to have decreased from 269.45 to $65.19{\mu}g/mL$ during storage. The UV-irradiation and HHP decreased from 263.46 and $268.35{\sim}281.16{\mu}g/mL$ to 243.42 and $244.09{\sim}269.29{\mu}g/mL$, respectively. In conclusion, these findings suggest that HHP can be used for the pasteurization, or sterilization, of carrot juice and the optimal condition is two minutes.

• Food Science and Industry
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• v.53 no.3
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• pp.284-294
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• 2020

High voltage pulsed electric field technology has been attracting attention in the the food industry as an eco-friendly nonthermal process technology using electrical energy. The lack of understanding of the equipment and the burden of equipment cost have not significantly increased the commercial application, but the potential as a technology to replace the heat process has been continuously increased. Sterilization of foods using the PEF process has been applied to liquid foods with low viscosity such as fruit and vegetable juices, but recently, high viscosity smoothies, high concentrate protein drink, mixed juice, and alcoholic beverages. Studies on sterilization of solid foods such as powders, raw meats are also being conducted. Also, the application of extraction and recovery of useful ingredients, activation of active compounds, pretreatment of drying, improvement of meat quality, changes of properties of starch has been studies.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.267-274
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• 2014

High pressure processing (HPP) is a non-thermal method used to prevent bacterial growth in the food industry. Currently, pasteurization is the most common method in use for most milk processing, but this has the disadvantage that it leads to changes in the milk's nutritional and chemical properties. Therefore, the effects of HPP treatment on the microbiological and chemical properties of milk were investigated in this study. With the treatment of HPP at 600 MPa and $15^{\circ}C$ for 3 min, the quantity of microorganisms and lactic acid bacteria were reduced to the level of 2-3 log CFU/ml, and coliforms were not detected during a storage period of 15 d at $4^{\circ}C$. An analysis of milk proteins, such as ${\alpha}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin by on-chip electorophoresis revealed that the electrophoretic pattern of the proteins from HPP-treated milk was different from that of conventionally treated commercial milk. While the quantities of vitamins and minerals in HPP-treated milk were seen to be comparable to amounts found in raw milk, the enzyme activity of lipase, protease and alkaline phosphatase after HPP treatment was reduced. These results suggest that HPP treatment is a viable method for the control of undesirable microorganisms in milk, allowing for minimal nutritional and chemical changes in the milk during the process.