• Food Science and Biotechnology
• /
• v.15 no.5
• /
• pp.721-727
• /
• 2006

This study was carried out to investigate the effect of hydrocolloids on the changes in physical properties of a model ice cream. The model ice cream contained water, sugar, skin milk powder, com oil, and 4 different hydrocolloid stabilizers (gelatin, pectin, hydroxyethylstarch, locust bean gum), was manufactured in a batch type freezer. The following physical characteristics of ice cream were examined: flow behavior, overrun, air cell size, ice crystal size, and melt resistance. With regard to flow behavior, all of aged mixes had a lower apparent viscosity relative to the mix before aging, and ice cream mix containing locust bean gum had the highest viscosity. Air cell size was observed to range from 20 to $38\;{\mu}m$, and ice cream with locust bean gum showed the largest size. There was an inverse correlation between overrun and air cell size. The ice crystal sizes of all samples ranged from 25 to $35\;{\mu}m$. Ice cream with added pectin contained the smallest ice crystal size, which was significantly difference from other stabilizers (p<0.05), and resulted in superior melt resistance with increased melting time compared to other samples.

• Journal of Environmental Health Sciences
• /
• v.27 no.1
• /
• pp.69-74
• /
• 2001

A study on temperature control of freezers & refrigerators in department stores and supermakets was conducted in Taegu are from July 15 through August 30 in order to determine how the temperature is effectively controled for food safety. Five departments and four supermarkets were selected randomly and fifty seven refrigerators and fifty nine freezers were inspected to observe temperature of thermometers and measure the temperature of the coolers by laser thermometer. The results are as follow; 1. Out of one hundred and sixteen coolers, eighty six (74.1%) were open type coolers and thirty (25.9%) were closed types (p<.05). 2. Twenty five (89.3%) of refrigerators and twenty three (82.1%) of freezers in department stores had thermometers and twenty seven refrigerators (93.1%) and twenty two (71%) of freezers in supermarkets had thermometers respectively (p<.01). 3. The measured temperatures of coolers increased in the afternoon to compared to the temperatures of them in the morning time (p<.01). The difference of temperatures of coolers between department stores and supermarkets was wider in the supermarkets and difference of temperatures of food items between refrigerators and freezers was wider in the refrigerators but the difference was not statistically significant. 4. The temperatures of forty four (84.6%) out of fifty two refrigerators within recommended ranges and those of forty two (93.3%) of forty five freezers higher than recommended ranges (p<.05).

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.2
• /
• pp.30-36
• /
• 2018

Since the freezer compartment and the refrigerating compartment are located side by side in a side-by-side refrigerator, the problems of the door height difference (DHD) and door flatness difference (DFD) have been constantly raised. Deformation of the cabinet of a built-in side-by-side refrigerator under food and thermal loads was analyzed by the finite element software ANSYS. The DHD and DFD, occurring due to the deformation of the cabinet, evaluated. From the results of the analysis of the cabinet, the 3D CAD software CATIA was used to geometrically translate and rotate the freezing and refrigerating compartment doors, in consideration of the displacement of the hinge fastening point. Then, the coordinates of two points on the upper corner of the doors were determined, and the DHD and DFD were obtained. It found that the thermal load, occurring under normal operation conditions, decreases the door height difference, but increases the door flatness difference. Values of the analyzed DHD and DFD appear smaller than the acceptance criteria used by the refrigerator manufacturer.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.1323-1328
• /
• 2004

This paper shows the study on the design of the spray-freeze dryer for the production of the pulmonary inhalation powders. Powder production and handling has been an integral part of pharmaceutical processing because of the wide use of oral dosage forms. There are a few commonly used powder preparation methods including mechanical milling, precipitaion, spray drying, freeze drying, and so on. In general, methods available for preparing inhalation powders are limited due to certain inhalation powder's sensitive nature to the processing environments. This is particularly true for preparing dry powder aerosols where the aerodynamic particle size$(<5{\mu}m)$ and the size distribution are pivotal. Supercritical fluid antisolvent and spray freeze drying have recently emerged as promising techniques for producing powders for use in microcapsulation. However, the aerosol applications of these powders are yet to be explored. The purpose of this study is to test the feasibility of using spray freeze-dried pulmonary inhalation powders for aerosolization.

• Korean Journal of Human Ecology
• /
• v.14 no.4
• /
• pp.693-707
• /
• 2005

This study investigates the over time changes in the ownership of kitchen items, electric or non-electric, and examines the patterns of the usage and ownership of the items after categorizing them as followings: cooking appliances, kitchen appliances directly related to storing food, food processing kitchen items, and dining items. The research findings are that refrigerators and rice cookers, among the electric items, had spread to almost every households by 1990s and at the same time about thirty non-electric kitchen items had been used. Refrigerators had been used by more than 100% of the households by 2000, and on top of that, twenty or more electric kitchen items such as Kimchi fridge and freezer had been used. In the case of non-electric kitchen items, approximately 50 to 70 sorts of them are used, which indicates an increase than in 1990s. Rice cookers and gas stoves, among cooking appliances, are recognized as the essential item, and they are actually frequently-used items. As to kitchen appliances related to storing food, each household owns one of the refrigerators and Kimchi fridges, and again they are both the frequently-used. As far as food processing kitchen items are concerned, each household owns at least one or more blenders and hand blenders, six or more knives, and five or more pans. Each household owns seventeen or more rice bowls and soup bowls and twenty-four or more plates. Small plates are more frequently used than large ones.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.1
• /
• pp.40-45
• /
• 2011

The purpose of research is to understand the characteristics of refrigeration system having a liquid-vapor phase separator after expansion device and precooling heat exchanger. After expansion process of typical refrigerant of freezer, R134a, the cold vapor of the expanded refrigerant mixture is separated in the liquid-vapor separator and introduced in the precooling heat exchanger to enable the liquid refrigerant to be subcooled. The analysis results showed that the increasing rate of refrigeration capacity and COP can be 8.6% and 1.4%, each. The cause of these performance improvements is due to the difference of the slope of saturated vapor and saturated liquid lines in Mollier diagram of refrigerant.

• Journal of Nutrition and Health
• /
• v.19 no.1
• /
• pp.3-15
• /
• 1986

This study was intended to investigate the rheological properties of the development formula of infant foods and the results are summarized as follow ; 1) Consistency of starch solutions measured by Brabender Anylograph and Brookfield viscometer showed that waxy rice and riece with malt had lower consistency and more rheological stability.The flow type of tested raw materials and formula was found to ？ pseudoplastic, as judged by n-value of 0.332 -0.692, and no yield value. 2) The influenced of temperature on consistency could be accounted for by the equation, In (n) = K(1/T) + const. this relationship indicated that consistency of tested sample increased as temperature decreased. The consistency of waxy rice, rice with malt and formula A were less affected by the temperature change. 3) Infant foods with malt(formula A ) ad with waxy rice maintained better freeze-thaw stability in terms of consistency and starch aggregation indicating that this infant food could be stored for a long term in the freezer section of the home refrigeratory without adverse effect on the product quality. 4) From the above experiments, it would necessarily follow that infant food can be easily made at home the food-stuffs generally available around us, and that the easiest and safest way to store them lies in making them into semisolid state, and in keeping them in frozen state.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.221-228
• /
• 2010

A sliding accident on the road have a high percentage by road freezing, especially, it is often appeared at bridges and Tunnel of freezing areas. Thus, the stability of road operations is enhanced by preventing a partial freezing phenomenon. According to the geothermal snow melting system analysis, a pattern of thermal conductivity is found out about pavement materials of concrete and asphalt when it is buried. The thermal conductivity study is essential that be applied the geothermal snow melting system according to heating exchanger pipe laying of lower pavements. The model tests are conducted on low temperature in freezer using the manufactured test model which is equal to pavement materials. And Many variables are discovered from numerical analyzes of the same conditions with model test.

• Culinary science and hospitality research
• /
• v.7 no.3
• /
• pp.85-98
• /
• 2001

This study was performed to describe the overall sanitation of baking utensils and equipments, employees, and environment in 9 bakeries. Microbiological tests on employees, utensils and equipments, were done according to standard procedure and included total plate count, coliforms, fungi and Staphylococcus aureus.. Microbiological testing is a value in determining hazards for developing a HACCP plan but were not detected throat and employee's hands before use. Staphylococcus aureus was detected nasal cavity and employees's hands after use. Employee's apron after use was detected fungi and coliform and was risk factor of cross-contamination to bread or cookies et al. Generally hygienic conditions of pan, kitchen board, knife, brush, and wooden scoop were worse than those of other baking utensils such as tray, bread tweezers, dusting brush and dish cloth. And refrigerator, freezer and fermentation chamber were detected fungi and coliforms. Total plate count of heating table, working table, distribution table, washbowl and refrigerator was increased in 2nd period. Temperature of refrigerator was 10.43$^{\circ}C$ and strict temperature control of refrigerations needs. Therefore, baking utensils and equipments were reguraly need to sterilize and clean. Additionary, it need to practice the effective sanitation education and training program for the bakery managers and employees.

• Korean journal of food and cookery science
• /
• v.12 no.1
• /
• pp.20-26
• /
• 1996

The present study was attempted to investigate and to evaluate various hydrocolloids as a stabilizer in improving texture of the frozen yogurt. Four kinds of hydrocolloids used in this study were CMC (carboxymethyll cellulose), PGA(propylene glycol alginate), LMP(low methoxyl pectin), and the combination of LBG(locust bean gum) and GG(guar gum). The viscosity of frozen yogurt mixes did not show any significant differences among four samples at 5$^{\circ}C$. However, as the temperature increased up to 50$^{\circ}C$, theviscosity of frozen yogurt mixes containing CMC, LMP, PGA decreased drastically except frozen yogurt containing the combination of LBG+GG. The overrun of frozen yogurt containing each hydrocolloid gradually increased and reached to about 53, 50, 54, and 35%, respectively, after 40 min of operating ice cream freezer. As the result of sensory evaluation in the texture of frozen yogurt and melt-down quality, the sample containing LMP was described as the most coarce & icy, crumbly, and sand-like characters. On the other hand, PGA sample was evaluated as not being icy, crumbly, but being chewy and soft in texture. However, any significant differences among four samples were not shown in melt-down quality.