• Title/Summary/Keyword: Storage Stability

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Processing of Water Activity Controlled Fish Meat Paste by Dielectric Heating 1. Formulation and Processing Conditions (내부가열을 이용한 보장성어육(고등어) 연제품의 가공 및 제품개발에 관한 연구 1. 원료${\cdot}$첨가물의 배합 및 가공조건)

  • LEE Kang-Ho;LEE Byeong-Ho;You Byeong-Jin;SUH Jae-Soo;JO Jin-Ho;JEONG In-Hak;JEA Yoi-Guan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.17 no.5
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    • pp.353-360
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    • 1984
  • As an effort to expand the utilization of mackerel which has been thought disadvantageous to processors due to the defects in bloody dark color of meat, high content of lipid, and low stability of protein, and to develope a new type of product, so called, preservative fish meat paste, the processing method was studied in which dielectric heating was applied by means of cooking, pasteurization, dehydration, and control of water activity. The principle of this method is based on that dielectric heating can initiate a rapid dispersion or displacement of moisture in the meat tissue so that the level of water acivity can be controlled by dehydration with hot air meanwhile the product is cooked, pasteurized, and texturized. And the product is finally heated with electric heaters and vacuum sealed to stabilize water activity and storage stability. In present paper, a formula for preparing the fish meat-stach paste, the conditions of dielectric heating and dehydration, shape and size of the product, and other parameters were tested to optimize the process operation. A formula of the fish meat-starch paste to provide proper textural properties and water activity was $10\%$ starch, $1.5\%$ salt, $3\%$ soybean, $0.6\%$ MSG, $2\%$ sucrose, and $3\%$ sorbitol against the weight of fish meat. A proper shape and size of the product to avoid foaming and case hardening during heating was sliced disc of 8 cm $diameter{\times}0.8$ cm thickness or $10{\times}10$ cm square plate with 1.0 cm thickness. The disc shape was recommended because it resulted more uniform heating, minimum foaming and case hardening. And it was also advantageous that disc was simply provided when the fish meat disc was stuffed in the same, solidified in boiling water for 2 to 3 minutes, and sliced. Condition of dielectric heating was critical to decide the levels of sterility, water activity, and textural property of the product. The temperature at the center of the meat disc slices was raised up to $95^{\circ}C$ in 1.5 minutes so that continuous exposure to microwave caused expanded tissue and hardening ending up with a higher water content. Heating for 5 to 6 minutes was adequate to yield the final water activity of 0.86 to 0.83(35 to $40\%$ moisture). It is important, however, that heating had to be done periodically, for instance, in the manner of 2.0, 1.5, 1.5, and 1.0 minute to give enough time to displace or evaporate moisture from the meat tissue. The product was dehydrated for 2 to 3 minutes by hot air of $60^{\circ}C$, 3 to 5m/sec and finally exposed to electric heaters for 5 to 6 minutes until the surface was roasted deep brown. These conditions of heating and dehydration resulted in a complete reduction of total plate count from an initial count of $5.3{\times}10^6/g$ to less than $3{\times}10^2/g$. General composition of the product was $40.1\%$ moisture, $20.8\%$ protein, $17.4\%$ lipid, $16.2\%$ carbohydrate, and $5.5\%$ ash. Textural properties revealed folding test AA, hardness 42, cohesiveness 0.53, toughness 4.6, and elasticity 0.8.

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A Study on the Preparation of Traditional Andong sikhe with Lactic Acid Bacteria (유산균을 이용한 전통안동식혜의 제조방법에 관한 연구)

  • Choi, Cheong;Son, Gyu-Mok
    • Journal of the Korean Society of Food Culture
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    • v.7 no.3
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    • pp.259-270
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    • 1992
  • The changes in life style today appear many ways. Many housewives turn away from home preparation of the time consuming traditional foods, such as 'Andong sikhe'. The importance, however, of succeeding the traditional cuisines is getting appreciated widely nowadays. This study aimed to investigate the preparation of Andong sikhe by use of pure culture inoculation and the improvement of storage stability by the addition of stabilizers to the product. Lactobacillus delbreuckii was selected for the pure culture inoculation in the fermentation. The changes in chemical composition such as total acidity, sugar content, amino acid and various forms of nitrogen during fermentation were determined. The changes in pH of the product, the enzyme activities and the population of lactic acid bacteria were also followed in the process of fermentation. The Lactobacillus dominated in the beginning of the fermentation but the Streptococcus out numbered the former as the fermentation proceeded. The crude protein content increased up to the 4th day of fermentation but slowly decreased there after. The pH of the product rapidly decreased to 4.2 by the 2nd day of fermentation. The total acidity reached to the 0.38% by the 2nd day of fermentation and kept on increasing slowly during the fermentation. The free sugar consisted of 6 kinds including maltose and one unknown sugar. The amino form nitrogen increased up to 38.5mg% at the 2nd day of fermentation and the product tasted best at this time. The ammonia form nitrogen, water soluble and salt soluble protein decreased during fermentation. Proline and aspartic acid were the two major free amino acids. The free methionine increased while the free lysine decreased in the process of fermentation. The major amino acids of water soluble and salt soluble protein were glutamic acid and aspartic acid. The arginine content of salt soluble protein increased as the fermentation proceeded. Linoleic, palmitic and oleic acid were the three major fatty acids and occupy 90% or more of the total fatty acids. The activities of acid protease and liquefying amylase reached to the maximum at the 4th day of fermentation while those of saccharogenic amylase and lipase reached to the peak at the 2nd day of fermentation.

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Effect of Different Stunning Time on Meat Quality of Broiler (육계 도축 시 전기 실신 시간이 육질에 미치는 영향)

  • Chae, H.S.;Ahn, C.N.;Yoo, Y.M.;Ham, J.S.;Jeong, S.G.;Lee, J.M.;Choi, Y.I.
    • Journal of Animal Science and Technology
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    • v.47 no.6
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    • pp.1017-1024
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    • 2005
  • This study was investigated the effect of the length of stunning time on pH, water holding capacity(WHC), cooking loss(CL), meat color and incidence rate of blood spot in broiler carcass. One-hundred and forty broiler chickens were slaughtered by three different length of stunning times(5 sec., 8 sec., 11 sec.) with the same electrical frequency(255Hz) and 50 voltage in a commercial abattoir. The WBS values and cooking loss of breast muscle were increased with increasing the stunning time, while WHC of breast muscle were decreased. Lightness(L* value) and yellowness(b* value) scores of leg muscle and skin stunned with 50V, 255Hz, 8 sec, 11 sec. were higher than those of broilers stunned with 50V, 255Hz, 5sec(P<0.05). But, there was no significant difference in color on breast and wing muscle. In subjective evaluation, frequence of the first grade had a trend of being increased by extending the stunning time. There was only a few cases of PSE chicken with 0.02%, while blood spot was observed at the highest rate for the 5 sec. treatment. TBARS indicated that a longer length of stunning resulted in a higher rate of fat oxidation. This experiment demonstrated that the length of stunning time has a significant effect on meat quality and its stability during chiller storage.

Physicochemical Properties of Commercial Sweet Potato Starches (시판 고구마전분의 이화학적 특성)

  • Baek, Man-Hee;Cha, Dong-Su;Park, Hyun-Jin;Lim, Seung-Taik
    • Korean Journal of Food Science and Technology
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    • v.32 no.4
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    • pp.755-762
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    • 2000
  • Physicochemical properties of commercial sweet potato starches manufactured by 7 different companies were investigated in comparison with corn and potato starches. Crude ash and protein content varied from 0.36 to 1.02%, and from 0.04 to 0.14% based on dry weight, respectively. The protein contents were relatively smaller than that of corn or potato starch. But whiteness of the sweet potato starches was less than that of corn or potato starch. Mean diameter of the sweet potato starch granules varied from 14.23 to $21.08\;{\mu}m$ depending on the company and all sweet potato starches showed bimodal size distributions. Pasting viscosity measured by Rapid Viscoanalyzer(RVA) also showed variations among the starches of different companies. The starch from D company in Korea had the lowest pasting temperature$(74.00^{\circ}C)$ whereas the starch from a phillippine company(P) did the highest one$(80.35^{\circ}C)$. The peak viscosity of sweet potato starches was higher than that of corn starch but lower than that of potato starch. The D company starch also showed the highest peak viscosity(2283 cp) among the starches tested. Paste breakdown by hot shearing ranged from 524 cp (S company) to 1279 cp (HL company). Textural properties of the starch gels appeared significantly different among the starches of different manufacturers. The greatest hardness of the gel was $137.90\;g_{f}$ at 1 day storage whereas the lowest value was $31.53\;g_{f}$. Except the starches from 2 companies (P and S), the sweet potato starches formed very soft and weak gels. P or S company starches formed the gels similar to potato starch. Syneresis by freeze-thawing treatments appeared less for sweet potato starch gels than that for corn starch gels, but greater than that for potato starch gel. The overall properties of the sweet potato starches varied by the manufacturing companies, and ranged between those of corn and potato starches.

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Comparison of Imported Wheat Flour Bread Making Properties and Korean Wheat Flour Bread Making Properties Made by Various Bread Making Methods (수입밀의 제빵 적성과 반죽법을 달리한 우리밀 제빵 적성의 비교)

  • Kim, Won-Mo;Lee, Gyu-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.3
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    • pp.434-441
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    • 2015
  • To develop dough methods for improving bread making properties of Korean wheat flour, straight dough methods (SDM) and dough and sponge methods (DSM) were applied. The bread making properties such as weight of bread, specific volume, baking loss, crumb color, and texture were analyzed. In comparison of flour properties between Korean wheat flour and imported wheat flour by Farinograph, Korean wheat flour showed less gluten network form ability than imported wheat flour. The dough making method affected bread quality such as weight of bread, specific volume, and baking loss. SDM had a more desirable effect on bread quality. Crumb color was lighter in bread made with Korean wheat flour compared to imported wheat flour, whereas dough making method did not affect crumb color. In consumer acceptance analysis, bread made by DSM showed higher consumer acceptance than that made by SDM. Regarding physicochemical changes during storage, bread made by SDM using Korean wheat flour showed higher chewiness, brittleness, and hardness than that made by imported wheat flour. However, bread made by DSM showed similar chewiness as bread made by SDM using imported wheat flour. The bread making properties of bread made by DSM is improved versus that of bread made with Korean wheat flour.

The Dietary Effects of Marigold Extracts on Egg Production, Egg Quality and the Production of Lutein Fortified Chicken Eggs (사료 내 매리골드 추출물의 첨가 급여가 계란 생산성과 계란 품질 및 난황 내 루테인 함량에 미치는 영향)

  • Kim, Eun-Jib
    • Korean Journal of Poultry Science
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    • v.41 no.2
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    • pp.135-142
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    • 2014
  • This study was conducted to evaluate dietary effects of Marigold extract on laying performance, egg quality, oxidative stability of egg yolk and lutein transfer into chicken eggs. A total of one-hundred eighty nine 55-wk-old Hy-Line Brown layers were divided into seven groups and fed control diet or each experimental diet containing 0.1, 0.3, 0.5, 1.0, 1.5 or 2.0% Marigold extract. Egg production, egg weight and daily egg mass were not affected by dietary treatments. The yolk colors in groups fed diets containing Marigold extract were significantly higher than that of control. The Haugh unit were tended to be improved by feeding of diets containing Marigold extract although there were no significant difference in egg shell strength and thickness. The MDA (malondialdehyde) contents in groups fed diets containing Marigold extract above 0.5% were significantly reduced than that of control. After 14d of storage, the Haugh unit values in groups feed diets containing 0.3 and 1.0% Marigold extract were significantly higher than that of control (p<0.05). The concentration of lutein in egg yolk increased by feeding of Marigold extract. When 2% Marigold extract was supplemented to the diet, lutein content of egg was increased as much as 1.71 mg/60 g. These results indicated that the use of Marigold extract in layer diets was effective in egg quality and for the production of lutein fortified eggs.

Effect of Supercritical Carbon Dioxide on Physicochemical Properties and Microbial Reduction of Freeze-Dried Bovine Liver (초임계 이산화탄소 처리가 동결 건조된 소간의 이화학적 특성 및 미생물 저감화에 미치는 영향)

  • Kim, Hye-Min;Woo, Sung-Woon;Kim, Ah-Na;Heo, Ho-Jin;Chun, Ji-Yeon;Choi, Sung-Gil
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.12
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    • pp.1847-1855
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    • 2015
  • Supercritical carbon dioxide ($SC-CO_2$) treatment has been becoming an important method for substituting the use of organic solvents for samples extraction prior to analysis due to its low toxicity, ease of handling, low cost of disposal etc. Freeze-dried bovine liver was treated with $SC-CO_2$ under different pressures (200, 300, and 450 bar) in order to investigate effects on physicochemical properties and reduction of microbial load. The yield of lipid extraction from bovine liver by $SC-CO_2$ treatment increased with increasing pressure, with values of 84, 86, and 90% in response to 200, 300, and 450 bar, respectively. Results of high performance liquid chromatography analysis showed that vitamin A and coenzyme $Q_{10}$ ($CoQ_{10}$), which is soluble in lipid, were almost removed from bovine liver by $SC-CO_2$ treatment. Saturated fatty acids ratio of bovine liver decreased with increasing pressure, whereas polyunsaturated fatty acids increased with increasing pressure. Total content of amino acids in bovine liver treated by $SC-CO_2$ was less than that of the control sample without treatment. The number of aerobic bacteria in bovine liver, which was stored at $5^{\circ}C$ for 5 days and freeze-dried, decreased from 6.2 to 4.2 log CFU/g by $SC-CO_2$ treatment at 100 bar for 3 h. Interestingly, coliform bacteria were not found in the bovine liver sample by $SC-CO_2$ at 100 bar for 3 h under all storage conditions. This indicates that $SC-CO_2$ treatment can effectively reduce coliform bacteria in the food matrix even at low moisture. In conclusion, freeze-dried bovine liver by proper $SC-CO_2$ treatment may be used as a potential high protein source, with increasing microbial safety and stability of lipid oxidation.

Degradation Kinetic and Mechanism of Methyl Tert-butyl Ether (MTBE) by the Modified Photo-Fenton Reaction (Modified Photo-Fenton Reaction을 이용한 Methyl Tert-butyl Ether (MTBE)의 분해 Kinetic 및 메커니즘 규명에 관한 연구)

  • Kim, Min-Kyoung;Kong, Sung-Ho
    • Journal of Soil and Groundwater Environment
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    • v.11 no.6
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    • pp.69-75
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    • 2006
  • Improper disposal of petroleum and spills from underground storage tanks have created large areas with highly toxic contamination of the soil and groundwater. Methyl tert-butyl ether (MTBE) is widely used as a fuel additive because of its advantageous properties of increasing the octane value and reducing carbon monoxide and hydrocarbon exhausts. However, MTBE is categorized as a possible human carcinogen. This research investigated the Modified Photo-Fenton system which is based on the Modified Fenton reaction and UV light irradiation. The Modified Fenton reaction is effective for MTBE degradation near a neutral pH, using the ferric ion complex composed of a ferric ion and environmentally friendly organic chelating agents. This research was intended to treat high concentrations of MTBE; thus, 1,000 mg/L MTBE was chosen. The objectives of this research are to find the optimal reaction conditions and to elucidate the kinetic and mechanism of MTBE degradation by the Modified Photo-Fenton reaction. Based on the results of experiments, citrate was chosen among eight chelating agents as the candidate for the Modified Photo-Fenton reaction because it has a relatively higher final pH and MTBE removal efficiency than the others, and it has a relatively low toxicity and is rapidly biodegradable. MTBE degradation was found to follow pseudo-first-order kinetics. Under the optimum conditions, [$Fe^{3+}$] : [Citrate] = 1 mM: 4 mM, 3% $H_2O_2$, 17.4 kWh/L UV dose, and initial pH 6.0, the 1000 ppm MTBE was degraded by 86.75% within 6 hours and 99.99% within 16 hours. The final pH value was 6.02. The degradation mechanism of MTBE by the Modified Photo-Fenton Reaction included two diverse pathways and tert-butyl formate (TBF) was identified to be the major degradation intermediate. Attributed to the high solubility, stability, and reactivity of the ferric-citrate complexes in the near neutral condition, this Modified Photo-Fenton reaction is a promising treatment process for high concentrations of MTBE under or near a neutral pH.

Moisture Sorption Characteristics of Powdered Soybean Curd (분말(粉末) 두부의 수분흡착(水分吸着) 특성(特性))

  • Kim, Dong-Man;Chang, Kyu-Seob;Yoon, Han-Kyo
    • Korean Journal of Food Science and Technology
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    • v.12 no.4
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    • pp.292-298
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    • 1980
  • In order to improve the storage stability of powdered soybean curd, moisture sorption characteristics of the curd stored at specific relative humidity and temperature were investigated. The results obtained are summarized as follows; 1. When the fresh soybean curd (2cm thickness) was dried in a hot air drier at $55^{\circ}C$, it took 18 hrs to reduce its moisture content from 85% to 8.8%, and drying rate was very high during the first 5 hrs. 2. Equilibrum moisture content (E.M.C.) of powdered soybean curd by freeze drying was higher than that of sample by got air drying, but the particle size did not influence E. M. C. 3. The monolayer value of freeze dried powder of high E. M. C was higher than that of the hot air dried(8.30 vs 7.35). 4. The free energy for moisture absorption of freeze dried powder at 11% RH were 1285.1 cal/mole, 1323.5 cal/mole at $15^{\circ}C$ and $30^{\circ}C$, respectively, and the free energy of freeze dried product was lower that of hot air dried product. 5. The moisture sorption rate constant was not affected by particle size, and it showed that the moisture sorption rate decreased as temperature was increased. The rate constant of powder produced by freeze drying were 0.00804 at $15^{\circ}C$ and 0.00696 at $30^{\circ}C$.

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The Physical and Thermal Properties Analysis of the VOC Free Composites Comprised of Epoxy Resin, and Dicyandiamide (VOC Free Epoxy Resin/Dicyandiamide 경화물의 배합비 변화에 따른 물리적 특성 및 열적특성 분석)

  • Kim, Daeyeon;Kim, Soonchoen;Park, Young IL;Kim, Young Chul;Lim, Choong-Sun
    • Clean Technology
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    • v.21 no.1
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    • pp.76-82
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    • 2015
  • Volatile organic compounds (VOC) free adhesives have been interested by many scientists and engineers due to environmental regulations and the safety of industrial workers. In this work, a series of composites composed with bisphenol A epoxy resin used as solvent, dicyandiamide, and promoter were prepared to investigate the most appropriate molar ratio for steel-steel adhesion. The cured test specimen of each composite were measured with universal testing machine (UTM) to figure out mechanical properties such as tensile strength, Young’s modulus, and elongation. Furthermore, the lap shear strength of the specimen was tested with UTM while impact resistance was measured with Izod impact tester. The composite whose molar ratio of epoxy resin to curing agent is 1 : 0.9 (sample 3), showed better tensile strength, coefficient of elastic modulus, elongation, and impact strength than other composites did. The highest tanδ from dynamic mechanical analysis (DMA) was observed from sample 2 (epoxy resin: dicy = 1 : 0.7) while sample 3 showed slightly lower tanδ than that of 2. The morphology of the fracture surface of the cured composites from SEM showed that the number of subtle lines on the surface caused by impact increase as the contents of amine curing agent accrete. Furthermore, the viscosity change of sample 5 (epoxy resin: dicy = 1 : 1.3) was observed to confirm its storage stability.