• Title, Summary, Keyword: frozen foods

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Changes of physical properties in model foods on thawing method (모형식품의 해동방법에 따른 물성변화)

  • Lee, Jae-Hak;Park, Young-Deok;Kang, Hyun-Ah;Chang, Kyu-Seob
    • Korean Journal of Agricultural Science
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    • v.21 no.2
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    • pp.133-141
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    • 1994
  • Optimal thawing conditions of frozen model foods containing protein and starch were nvestigated at various thawing conditions such as room temperature, hot air, and microwave heating. Hardness of the frozen model foods was getting higher as the water content increased. Thawing rates at room temperature, hot-air heating at $50^{\circ}C$, and microwave heating were 0.02 Kg/min, 0.08 Kg/min, 0.01 Kg/min, respectively. Final thawing time was as follows; control 60min, 5% sucrose: 50 min, 10% sucrose: 30 min, 5% NaCl: 30 min. Total drip loss was as follows; room temperature thawing: 22.5%, 200W microwave thawing 1.3%, and $50^{\circ}C$ hot air thawing nearly negligible.

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Influence of Thermal Oscillation on Quality of Frozen Foods Stored in Domestic Refrigerator (가정용 냉장고의 제상 주기와 온도 변화가 저장 식품의 품질에 미치는 영향)

  • Kang, Gil-Jin;Auh, Joong-Hyuck;Kim, Myo-Jeong;Cho, Kwang-Yeun;Choi, Young-Hoon;Jung, Dong-Sun;Kook, Seung-Uk;Park, Kwan-Hwa
    • Korean Journal of Food Science and Technology
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    • v.28 no.4
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    • pp.624-631
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    • 1996
  • Effect of fluctuation range and intervals of defrosting temperature on quality of frozen foods stored in a domestic refrigerator equipped with an automatic defrost system was evaluated. As defrost system was operated, temperatures of domestic refrigerators were elevated from $-18^{\circ}C\;to\;-5^{\circ}C\;and\;-15^{\circ}C$, and fluctuation intervals were l6 hrs and 30 hrs, respectively. Quality deterioration such as protein denaturation, vitamin loss, exudate production and changes in appearance of frozen foods was minimized by reducing temperature oscillation during storage. Considerable effects of thermal oscillation on ice crystal sizes were observed for frozen beef tissue and ice cream. TTI (time temperature indicator) system also proved that the temperature control of defrost system in domestic refrigerator can improve the quality of foods during storage.

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Lipoxygenase and Off-flavor Development in Some Frozen Foods (일부냉동식품에서의 Lipoxygenase와 이취발생관계)

  • Lee, Young-Chun
    • Korean Journal of Food Science and Technology
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    • v.13 no.1
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    • pp.53-56
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    • 1981
  • Several tests were conducted to study lipoxygenase activity and off-flavor developement in frozen sweet corn. Fresh corn contained about 60% of total lipoxygenase activity in the germ section. When non-blanched frozen sweet corn was stored at $-10^{\circ}F$, it developed off-flavor and most significant changes in the flavor profile of off-flavored sweet corn was $4{\sim}5$ times higher hexanal peaks. The high hexanal peaks observed in the sterilized sweet corn with added lipoxygenase, alone and in combination with other enzymes, suggested the fact that high hexanal peaks in off-flavored sweet corn could be due to an oxidative reaction of lionleic acid (and other unsaturated fatty acids) catalyzed by lipoxygenase. Based on lipoxygenase activity and linoleic acid content in sweet corn, this reaction occur most heavily in the germ section of sweet corn. There was a significant relationship between flavor score of frozen stored corn-on-the-cob and hexanal peak in the germ section of corn-on-the-cob. This result indicated that hexanal peak could be used as an objective index of off-flavor development in frozen sweet corn.

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The Study for Application of Commercial Modified Starch to Frozen and Retort Foods (냉동 및 레토르트식품에서 상업적 변성전분의 적용에 관한 연구)

  • 장재권
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.881-889
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    • 1998
  • For the application of the commercially modified starch in frozen and retort foods, apparent viscosity and water loss were measured at each stages of heating, sterilization and freezing-thawing stages. Apparent viscosity showed the exponential increase with concentration and the slopes of apparent viscosity against concentration in the Firm-Tex(hydroxypropyl distarch phosphate), Hi-Flo(acetylated distarch adipate) and Colflo 67(acetylated distarch adipate) from waxy maize starch were higher than those of Amyloacetate M20(starch acetate) and X-amylo 250(distarch phosphare) from potato starch. In the presence of 1 or 2% NaCl, X-amylo 250 among modified starches showed the increase in water loss and the decrease in apparent viscosity, whereas Colflo 67, Hi-Flo and Firm-Tex were little affected by NaCl. In the presence of 1 or 2% sucrose, water loss and apparent viscosity of the modified starches were not affected. In the range of pH 4~8, water loss and apparent viscosity of the modified starches had no change but the differences were detected to some extent between each of heating, sterilization and freezing-thawing stages. In the apparent viscosity and water loss of the modified starches after 3 week storage from heating and sterilization, Hi-Flo, Amyloacetate M20 and X-amylo 250 were not changed at the storage period, and the overall acceptability of retort food containing the modified starches such as Firm-Tex and Amyloacetate M20 were favored more than others. In the apparent viscosity and water loss of the modified starches which have been frozen and thawed three times repeatedly, Colflo 67, Hi-Flo and Firm-Tex were not changed in freezingthawing, and the overall acceptability of frozen food containing Firm-Tex was most favored.

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Measurement of Lipid Oxidation Rates in Semi-prepared Frozen Muscle Foods During Various Storage and Reheating Conditions (반조리 냉동 육류제품의 저장 및 재가열 방법에 따른 지방 산화율 측정)

  • 송은승;강명화
    • Korean journal of food and cookery science
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    • v.9 no.2
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    • pp.88-93
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    • 1993
  • Semi-prepared frozen muscle foods purchased from local industry were tested for lipid oxidation. The effects of various storage conditions, cooking methods, defrosting methods and reheating methods on rancidity were examined using TBA assay and sensory evaluation. TBARS values were increased faster in cooked samples than in uncooked ones during storage periods. During refrigeration of cooked samples, TBARS values were increased significantly for 15 days (p<0.001). In defrosting experiments, refrigerated defrosting was proven to be better compared with room temperature or microwave defrosting (p<0.05). For overall explanation, stepwise regression analysis was done and the results are in this order: storage conditions, cooking methods, moisture content, and lipid content. Using these 4 variables, TBARS values could be explained by 40~53%.

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The Survey of Housewives' Perception for the Development of Refrigerated Convenience Foods for Koreans (한국형 냉장편의식 개발을 위한 주부들의 인식 조사)

  • Kwak, Tong-Kyung;Lee, Kyung-Eun;Park, Hye-Won;Ryu, Kyung;Choi, Eun-Jung;Hong, Wan-Soo;Jang, Hye-Ja;Kim, Sung-Hee
    • Journal of the Korean Society of Food Culture
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    • v.12 no.4
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    • pp.391-400
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    • 1997
  • To provide basic information for the development of refrigerated convenience foods for Koreans, 492 house-wives residing in Seoul and Kyunggi Province were surveyed concerning satisfaction of buying precooked convenience foods, frequency of using them, preferred Korean dishes, and willingness to buy the convenience foods if they are developed. Statistical data analysis was completed using SAS package program. The satisfaction mean score of the marketed precooked convenience foods was 2.73 out of 5 and the housewives were least satisfied with feed additives and sanitation factors. The factors affecting satisfaction in purchasing were sanitation, taste, variety of type, nutrition, price, and food additives for side-dishes sold refrigerated or at room temperature, and taste, sanitation, variety of type, price, nutrition, and food additives for frozen prepared foods in order respectively. The frequency of using the precooked convenience foods was generally low but that of using the pickled dishes, Jokbal Soondae, and frozen prepared foods was relatively high. The answer of 'the thought that meals should be prepared in households' was the primary reason for avoiding using the precooked convenience foods and 'no time to cook' was the most frequent answer among the reasons for using them. Currently, the precooked convenience foods were used for snacks mainly, but the usages to be expected to increase were for lunchbox, main dishes, snacks, side dishes, special occasions foods, and leisure foods in order. Based on preference and buying priority, the dishes needed to be developed as refrigerated convenience foods among Korean dishes were identified. The result showed that 'preference' was not consistent with buying priority and the housewives perceived the factor of 'convenience' more importantly than 'preference' in purchasing the convenience foods.

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Changes of Physical and Sensory Quality in Home-delivered meals for elderly as affected by Packaging methods and Storage conditions 3 (노인을 위한 가정배달급식의 포장방법 및 저장조건에 따른 물성ㆍ관능적 품질 변화 3)

  • 김혜영;류시현
    • Korean journal of food and cookery science
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    • v.19 no.3
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    • pp.374-389
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    • 2003
  • The Purpose of this study was to propose the most effective packaging method and storage conditions to apply to home-delivered meals for the elderly Changes in the physical and sensory qualities of pan fried oak mushroom and meat, soy sauce glazed hair tail and roasted dodok, in wrap packaging, top sealing and vacuum packaging were evaluated during storage at 25, 4 and -18$^{\circ}C$, for 5 days. The speed of falling-off in the foods qualities, under chilled and frozen storage conditions did not differ much as the 5 day storage period was too short for a proper assessment. The sensory characteristics of taste and texture were better evaluated in the chilled than in the frozen storage. The most effective packaging method at all the storage temperatures was the vacuum packaging, which assured the safety of the foods by the removal of oxygen. The lightness, springiness and hardness were significantly influenced by the storage temperature, period and packaging method, while the sensory characters were affected by storage temperature and the period. In conclusion, the quality of the vacuum packed pan fried oak mushroom and meat and soy sauce glazed hair tail, in frozen storage, were still fresh after the five days of the experiment. The shelf-life of those foods with wrap packaging, in chilled storage, were suggested to be three days. The quality of the roasted dodok, with vacuum packaging in chilled storage, was preserved for five days.

Nutritional Characteristics of the Major Commercial Frozen Seafood Products in Korea (국내 시판 주요 냉동수산식품의 영양 특성)

  • Kim, Yeon-Kye;Nam, Ki-Ho;Park, Sun Young;Kim, Do Youb;Kang, Sang In;Han, Sang-Kuk;Kim, Jin-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.1
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    • pp.1-12
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    • 2019
  • We investigated the nutritional components of the major commercial frozen seafood products (MCFSP) [sliced frozen-skipjack tuna (ST), -bigeye tuna (BET), -bluefin tuna (BFT), -yellowfin tuna (YT), fish steaks (FST), fish pancakes (FP), fish cutlets (FC), seafood cake balls (SCB), fried shrimp (FS), shrimp patties (SP), shrimp cutlets (SC)] in Korea. All species of sliced frozen tuna and FST were classified as low-calorie foods; the other frozen seafood products were classified as medium-calorie foods. The MCFSP were significant sources of nutritional and functional minerals: the SCB and SC provided calcium; the FST, FC, and SCB provided phosphorus; the BET, YT, and FST provided potassium; the FST, FC, and BFT provided magnesium; the FST, FP and SC provided iron; the SCB, FS, SP, and SC provided zinc; the YT and SCB provided copper; and the FC provided manganese. The total amino acid contents of the MCFSP were in the range of 6.85-26.34 g/100 g. Glutamic acid was the major amino acid in the SCB, FS, SP, and SC. Fatty acid contents were in the range of 386-2,925 mg/100 g; the major fatty acids in the ST, BFT and YT were 16:0, 18:1n-9, 22:6n-3. The MCFSP were not a significant source of vitamin A or riboflavin.

Detection of E. coli O157:H7 and Listeria monocytogenes, and Appraisal for Microbiological Qualities in the Commercial Frozen Yogurt Products in Korea (국내 시판용 Frozen Yogurt의 병원성 미생물 검출 및 미생물학적 품질 평가에 관한 연구)

  • 윤성식
    • Food Science of Animal Resources
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    • v.18 no.1
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    • pp.63-74
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    • 1998
  • Recently the high outbreaks of intestinal disease caused by the consumption of frozen dairy foods containing pathogenic bacteria has generated considerable interest in the causative agent such as Listeria monocytogenes and E. coli O157:H7. This study was carried out to detect the above pathogens and compare the microbiological qualities of three commercial forzen yogurt products. The main results obtained were as follows. L. monocytogenes coliforms and E. coli O157:H7 were not detected in the total of seven frozen yogurt samples. For microbiological qualities the viable lactic counts of products manufactured by FA company were about 2.9$\times$108 -1.6$\times$109cfu/ml 1.7$\times$106 cfu/ml for FB's and 1.2$\times$106 cfu/ml for FC's The PH values of FA's FB's and FC's products was in the range of pH 4.1~5.3 and the values of FA's were 4.1~4.6 compared by the pH 5.2~5.3 of FB's and FC's products. During refrigeration of the test samples the survival rates of L. monocytogenes spiked into thawed frozen yogurt sample(FA's FB,s and FC's) were 0.55% 15.61% and 16.89% respectively. On the other hand E. coli O157:H7 and L. monocytogenes were 12.4% and 25.0% for FA's 10.8% and 20.8% for FB's and 10.26% and 22.7% for FC's under 37$^{\circ}C$ storage, As the results described above each frozen yogurt products were different in microbiological qualities. The survival rates of pathogens spiked into the samples increased with the pH of the products. This indicates that the pH or any other factors pre-sumable supressed the growth of E. coli O157:H7 and L. monocytogenes in frozen yogurt products.

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Perception and Consumption Status of Food Labeling of Processed Foods among College Students in Daegu.Gyeongbuk Area (대구.경북지역 대학생의 식품 표시에 대한 인식 및 가공식품 소비 실태)

  • Park, Eo-Jin
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.6
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    • pp.671-680
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    • 2013
  • This study was conducted to examine the consumption realities of processed food and the perception of food labeling with targets of university students attending schools in Daegu and Gyeongbuk areas. The reason for buying processed food was because it is easy to cook. As for the number of using processed food, it was answered that everyday dairy products, noodles, breads and snacks for 3~4 times a month, and meat processed foods, canned foods, sauces and frozen foods for 2~3 times a month. With regard to selecting processed products, both male and female students answered with taste and price first, barely considering the safety and nutritional elements. It turned out that they check the price, expiration date and country of origin in order upon buying processed foods. Most of them recognized food labeling, but answered that they checked it sometimes in order to check the 'expiration date' and the 'calories'. They were aware of the food nutritional contents indication. It was turned out that male students check it for nutrients and female students for weight control. The effect of the processed food indication was that it is easy to choose the necessary foods for health and as well as for comparing the food with other products. The satisfaction of the food labeling system was mediocre. The results indicated that the food indication system needs to be educated or promoted.