• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.8 no.2
• /
• pp.90-100
• /
• 1975

The estimation of the pre-processing condition of oyster is of great importance for distributors and processors. This study was attempted to establish the basic data for evaluating the processing suitability of oyster, which is the most important shellfish for domestic use and export. The data were analysed by measuring the condition index, chemical composition and heavy metal content of oysters. In order to eliminate the manual work that has to be done on a tightly closed oyster shell and avoid shrinkage in the oyster meat which is attendant on the steaming process, chemical means to open oyster were examined. finding the method of pretreatment of polyphosphate for frozen oysters were attempted to improve the product quality. The prevention of undesirable color change of the canned oyster meat is another problem to solve. The important results are as follows : 1. The ratio of meat volume and meat weight to the holding capacity by shells may be useful as an index to measure the condition index of oysters. 2. As a whole, monthly changes of moisture and fat content in oysters were reversely correlated. Protein content slightly decreased from April and rapidly decreased in July, and again rapidly increased in August but from September to November decreased slightly. In April, the content of glycogen was 4 percent. From this period to September, glycogen was rapidly decreased. From July to September, it was only 0. 7 to 1 percent but increased from October. There were little seasonal changes in pH value. The pH value of oyster meat was 6.0 to 6.2. The crude ash content was slightly decreased from June to August. 3. The range of monthly change of heavy metal content are as follows: Total mercury was 0 to 0.019 ppm, cadmium was 0.026 to 0.053 ppm, copper was 0.111 to 0.594 ppm, and lead_was 0.061 to 0.581 ppm. 4. By the results of condition index, chemical composition and heavy metal content of oysters, the suitable harvest season as raw materials for processing was the end of December to the end of May of next year. 5. The pretreatment of 10 percent polyphosphate in 5 percent salt solution of oyster meat appeared effective to reduce thawing drip during cold storage. 6. The pretreatment of $Na_2EDTA$ and BHA did not show the color prevention effect to the canned oyster meat during storage. 7. Magnesium chloride affected to open the valves of oysters.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.26 no.1
• /
• pp.26-30
• /
• 1993

To suggest a thermal diffusivity predicting equation for mixed meat products, heat penetration curves of pork products containing filefish meat were plotted in the temperature range of $80.44{\sim}121.03^{\circ}C$, and thermal diffusivities were calculated from the heat penetration curves. The ground pork was mixed with minced filefish meat and some additives such as lard, isolated soy protein, $1.5\%$ of table salt and $2\%$ of polyphosphate to control the composition and texture of products, and then stuffed into a model can. The heat penetration curves were plotted using a thermocouple fixed at the slowest heating point of the can. At constant heating temperature, the thermal diffusivities of the products increased linearly with increasing moisture content. The values of the products with constant moisture content also increased linearly with increasing heating temperature. The thermal diffusivities of the products with moisture content of $51.47{\sim}80.20\%$ could be predicted by following equation: $${\alpha}_p=(3.045+0.59{\cdot}X_w){\cdot}{\alpha}_w+0.0098{\cdot}10^{-6}{\cdot}X_w-0.4287{\cdot}10^{-6},(m^2{\cdot}s^{-1})$$ Maximal differences of the thermal diffusivities predicted with this equation were in the range of ${\pm}0.8\%$ compared with the practical values. This equation and another predicting equation obtained from the previous study for the pork product without fish meat could be simplified as following one equation, and the maximal differences of the thermal diffusivities predicted with this equation for both products with and without fish meat were in the range of less than ${\pm}2.5\%$ $${\alpha}_p=(2.290+0.54{\cdot}X_w){\cdot}{\alpha}_w+0.0024{\cdot}10^{-6}{\cdot}X_w-0.3535{\cdot}10^{-6},(m^2{\cdot}s^{-1})$$

• Korean Journal of Poultry Science
• /
• v.15 no.2
• /
• pp.81-91
• /
• 1988

The purpose of this research is to analyze the tendencies of poultry consumption in Korea. The information used is the data collected three times during the period from Sept. 1, 1985 to April 30, 1987 throughout the major cities. Those who participated in the survey are 2, 598 including housewives, nutritionists, cookers, group feeding institutions, woman's organizations, and the students of doing nutrition－related studies. Consumer preferences for poultry meat and eggs tend to move toward high quality and more strict sanitary standards. Following this line of consumer preference changes, the poultry product marketing supported by cold chain system is rapidly developing. Household consumption of poultry meat largely consists of hi－and semi－broilers but the household demand for these two broilers tends to decrease steadily over time. In general poultry meat consumption appears to be affected by consumer taste rather than market factors such as prices. In addition consumer choices are quite different depending on poultry meat parts which are preferred in order of drum sticks, wings, and breasts. In particular drum sticks are most preferred than any other parts. An important problem in poultry production is related to consumption seasonality since large part of poultry meat consumption is concentrated during the summer season. Another problem is associated with little development of cooking methods. At present there are two types of primary commercial cooking techniques, fries and samgaetang (boiled chicken with jinsang and rice). For promoting domestic poultry meat disposal and reducing the demand seasonality, new cooking methods should be developed and followed by more aggresive advertisements. In domestic egg trade, smaller packing units(i.e., 10 eggs per unit) tend to bi preferred to large ones (i.e., 30 eggs per unit). In consumers egg purchasing decisions nearness to the shops and convenience appear to be important factors. For egg shell colors consumers recognize that there is no difference in nutritional values. However, survey results show that consumers highest preference lies in eggs with brown color. Eggs are most popular among children and preferred in order of middle－and high－school students, 17-25 age people, and adults. Egg prices are concieved relatively cheap to its nutritional values. In house－holds eggs are consumed in the forms of fries, side dishes, and lunch basket dishes. However, high level of cholesterol content in eggs appears to be an important problem in promoting eggs consumption.

• Food Science of Animal Resources
• /
• v.33 no.6
• /
• pp.763-771
• /
• 2013

This study was carried out to investigate the effects of various temperatures of electro-magnetic resonance and air blast freezing methods on the physicochemical quality of meat. Beef (loin and round), pork (belly and ham) and chicken (breast and leg) were purchased at a commercial market, and the meat was frozen using three methods: air blast freezing ($-20^{\circ}C$ and $-45^{\circ}C$) and electro-magnetic resonance quick freezing. Changes in the physicochemical properties of meat were analyzed by drip loss, cooking loss, water holding capacity (WHC) and proximate compositions. In comparison, regardless of the animal species and cuts of meat, electro-magnetic resonance quick freezing (2 h) resulted in a completely frozen product in a much shorter time than $-20^{\circ}C$ and $-45^{\circ}C$ air blast freezing (24 h and 8 h, respectively). Drip loss of loin which had underwent electro-magnetic resonance quick freezing were significantly (p<0.05) lower than those of the other two treatments, but cooking loss and water holding capacity were the highest at 43.7% and 60.7%, respectively (p<0.05). Characteristics such as crude protein, crude fat and moisture compositions showed significant differences, depending on the cuts and freezing methods (p<0.05). The fat composition of electro-magnetic resonance quick frozen loin and round were significantly low (p<0.05). However, moisture content was the highest compared to other freezing methods, as 67.1% and 71.9%, respectively (p<0.05). Electro-magnetic resonance quick freezing was an appropriate way to reduce the deterioration of meat quality due to freezing, and the drip loss was least for the part with low moisture, low protein, and high fat.

• Food Science of Animal Resources
• /
• v.27 no.4
• /
• pp.531-537
• /
• 2007

Small amounts of trans fatty acids exist naturally in beef and dairy foods. Also, they can be produced in the process of partial hydrogenation to manufacture shortning or margarine. They can provide a better palatability and shelf life. According to the recently studies, trans fatty acids can raise health risk such as heart diseases and coronary artery diseases. They can also increase low-density lipoprotein (LDL) cholesterol and decrease high-density lipoprotein (HDL) cholesterol in the blood plasma, therefore increasing the risk of atherosclerosis and diabetes. The aim of this study was to determine total lipids and trans fatty acids (TFAs) content in processed foods and meat products. The analysis of trans fatty acids was performed in 28 samples of donuts, 18 samples of bakeries, 4 samples of frozen doughs, 2 samples of popcorns, and 4 samples of meat products (ham, sausage, nuget, and bacon). Total lipids in processed foods and meat products were extracted by chloroform-Methanol method and acid digestion, respectively. They were analyzed by gas chromatography using a SP-2560 column and flame ionization detector. The amounts of TFAs per 100 g of foods were 0-3.3% (0.74% on average) in donuts, 0.2-5.8% (1.18% on average) in bakeries, 0.2-6.3% (1.93% on average) in frozen doughs, and 0-5.8% in popcorns. Meat products such as ham, sausage, and nuget analyzed 0.1% of TFAs, respectively and trans fatty acids in bacon were not detected. As a result, the distribution of TFAs in processed foods was widely ranged from O% to 6.3% according to manufacturers and types of products, whereas the content of TFAs in meat products ranged from 0% to 0.1%.

• Food Science and Preservation
• /
• v.16 no.5
• /
• pp.686-698
• /
• 2009

We sought basic data for product development and storage improvement of abalone. We explored drying methodologies, such as shade drying, cold air drying, and vacuum freeze drying. We also examined various physicochemical features of both meat and viscera. Raw abalone meat had $78.88{\pm}1.01%$ moisture, $9.24{\pm}0.27%$ crude protein, and $10.05{\pm}0.81%$ carbohydrate (all w/w). The moisture level of dried abalone meat was highest after cold air drying, at $18.38{\pm}0.91%$, and lowest after vacuum freeze drying, at $1.05{\pm}0.05%$. The total amino acid content of raw abalone meat was $17,124.05{\pm}493.18\;mg%$, and fell after shade-drying to $12,969.92{\pm}583.65\;mg%$, and to $13,328.78{\pm}653.11\;mg%$ after cold air drying. The total free amino acid content of raw abalone meat was $4,261.99{\pm}106.55\;mg%$, and rose after shade-drying to $6,336.50{\pm}285.15\;mg%$, to $5,072.04{\pm}248.53\;mg%$ after cold air drying, and to $4,638.85{\pm}218.03\;mg%$ after vacuum freeze drying. The fatty acid proportions in raw abalone meat were $47.00{\pm}0.99%$ saturated, $22.18{\pm}1.05%$ monounsaturated, and $30.82{\pm}1.45%$ polyunsaturated. In the viscera, however, the proportions were $36.72{\pm}0.74%$ saturated, $25.44{\pm}1.12%$ monounsaturated, and $37.84{\pm}1.67%$ polyunsaturated. The contents of chondroitin sulfate in raw abalone were $11.95{\pm}0.35%$ in meat and $7.71{\pm}0.19%$ in viscera (both w/w). After shade-drying, the chondroitin sulfate content was $16.57{\pm}0.90%$ in meat and $9.24{\pm}0.50%$ in viscera. The figures after cold air drying were $16.17{\pm}0.79%$ and $12.44{\pm}0.61%$, and those after vacuum freeze drying $25.17{\pm}1.16%$ and $15.22{\pm}0.70%$ (thus including the highest meat content). The level of collagen in raw abalone was $69.80{\pm}3.07\;mg/g$ in meat and $40.62{\pm}1.79\;mg/g$ in viscera. Meat and viscera dried in the shade had $144.05{\pm}7.78\;mg/g$ and $44.16{\pm}2.39\;mg/g$ collagen, respectively, whereas the figures after cold air drying were $133.29{\pm}6.53\;mg/g$ and $69.20{\pm}3.39\;mg/g$, and after vacuum freeze drying $137.51{\pm}6.33\;mg/g$ and $60.61{\pm}2.79\;mg/g$. Volatile basic nitrogen values of raw abalone showed a higher content in viscera, at $19.01{\pm}0.84\;mg%$, compared to meat ($10.10{\pm}0.44\;mg%$). The value for shade-dried abalone meat was $136.77{\pm}7.37\;mg%$ and that of viscera $197.97{\pm}10.69\;mg%$. After cold air drying the meat and visceral values were $27.32{\pm}1.34\;mg%$ and $71.37{\pm}3.50\;mg%$, respectively.

• Journal of the Korean Society of Food Culture
• /
• v.1 no.3
• /
• pp.231-247
• /
• 1986

Age specific characteristics in Korean diet and their changes were analyzed with the demand model including the number of family members by age group as independent vasiables Urban household budget data, 773 household data in 1977 and 947 household data in 1983, was applied to the demand model. A series of F-test was carried out to set up the age groups by food item. The main results can be summarized as follows; 1. Food consumption patterns are remarkably different between 0-13 years old age generation and over 40 years old generation. The 0-13 years old generation reveals higher preference for milk, wheat product, fruit and milk and lower preference for rice and vegetable than any other age generation. This characteristics of the childhood diet has been formed In the generation born after 1970's and thus will be reserved as their generational characteristics. On the other hand, over 40 years old age group prefers rice and fish to fruit, milk and wheat product. Therefore we can conclude that over 40 years old age group maintains the traditional Korean diet pattern. 2. The preference for fish is low. in 20-30 years old age group than in any other age group and wheat product is Preferred highest in 6-13 years old age group of all age groups. Meanwhile the most remarkable change In food consumption pattern is shown in meats and vegetables. Namely in 30 40 years old age group the preference for meat has increased substantially and that vegetable has decreased to a great extent. 3. The declining per capita consumption of rice spreads like a wave to higher age. groups, but over 40 years old age group bas played an important role in reducing the decreasing rate of rice consumption. In order to restrain the declining rice consumption a special integrated food policy is required to induce rice consumption in less 30 years old generation.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.2
• /
• pp.139-146
• /
• 2013

Surimi products are among the most prominent seafoods in Korea. Together with fish meat, wheat flour is a major ingredient in the preparation of surimi products. Rice flour, however, can be an effective ingredient in enhancing the rheological characteristics of surimi products. In this study, we evaluated the potential of rice flour as an agent to replace wheat flour in surimi products. The effects of rice flour milling types and addition methods on the rheological and sensory properties of surimi products were investigated. Among different addition methods, the surimi product containing non-treated rice flour showed better gel strength and sensory properties than products containing paste (1:1.3 rice flour/water, w/v) and steamed paste (steamed at $100^{\circ}C$ for 30 min). According to the gel strength results for surimi products with added roll-mill (40 mesh) and jet-mill (180 mesh) rice flours, the roll-mill rice flour shows good potential as a replacement for wheat flour. When considering gel strength and sensory properties, an effective amount of rice flour to add was 10-15% (w/w). In conclusion, the rheological and sensory properties of surimi products containing rice flour were comparable with those of a premium commercial surimi product. Therefore, rice flour might be an effective alternative to wheat flour for premium surimi products.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.21 no.4
• /
• pp.239-245
• /
• 1988

As a part of the studies on effective utilization of polyunsaturated lipids in sardine (Sardinops melanosticta) when the refined sardine oil was added to surimi-based product as a dietary supplement of biologically active fatty acids, eicosapentaenoic aicd and docosahexaenoic acid, storage stability and the effect to the qualify of the product was tested. Addition of the refined sardine oil up to $5\%$ to surimi did not affect the textural properties of the product. And the polyunsaturated fatty acids of the sardine oil was fairly stabilized when it stored for 1 month at room temperature and 43 days at $5^{\circ}C$. These results suggested the possibility that the refined sardine oil or other fish oils containing highly polyunsaturated fatty acids, especially EPA and DHA could be used as a food ingredient for dietary supply of the lipids.

• Korean Journal of Food Science and Technology
• /
• v.4 no.4
• /
• pp.265-270
• /
• 1972

An attempt was made in this study to investigate the possibility of processing squid along with pork into an intermediate moisture food, as an acceptable new item in Korea. To obtain a palatable and low cost product, portions of mixture consisting of equal amounts of ground squid and pork were cooked in soy sauce for 20 min, soaked in glycerol for 20 min at $80^{\circ}C$, and then air dried for 90 min at $60^{\circ}C$. During storage for 42 days in saturated humidity incubator at $37^{\circ}C$, the total microbial counts of the products packaged in polyethylene (0.05 mm), polypropylene (0.05 mm) and plastic laminated aluminum foil were decreased from 230 per gram to 40, 20 and 10 per gram respectively. In another long range storage test of 6 months, the results paralleled the above trends. Even though the TBA value of the samples increased during the storage, it was not so serious as to damage on the organoleptic quality of this product. The results indicate that stored product was as acceptable as the freshly prepared one.