• Title/Summary/Keyword: physicochemical qualities

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Effects of Gamma Irradiation and Ethylene Oxide Fumigation for the Quality Preservation of Spices and Dry Vegetables (건조향신 조미식품의 품질보존을 위한 효과적인 살균방법에 관한 비교연구)

  • 신광순;마점술;조종후
    • Journal of Food Hygiene and Safety
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    • v.4 no.2
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    • pp.119-132
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    • 1989
  • Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.

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Study on Waxy Corn X. Analysis on Botanical Characteristics, Physicochemical Properties Related to Table Qualities of the Developed Waxy Corn Hybrids (찰옥수수 연구 X. 육성된 찰옥수수 교잡종의 식물학적 특성 및 식미관련 이화학적 형질)

  • Lee, Moon-Sub;Bok, Tae-Gyu;Choi, Yun-Pyo;Hong, Bom-Young;Jo, Yang-Hee;Lee, Hee-Bong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.1
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    • pp.8-13
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    • 2011
  • This study was carried out to compare botanical characteristics, physicochemical properties related to table quality and feed values and develop a new variety among 12 developed waxy com hybrids. These materials were produced in 2008 and cultivated in 2009 at Com Breeding and Genetics Farm of Coll. of Agri. & Life Sci., Chungnam Nat'l Univ. Botanical characteristics of used waxy com hybrids showed large difference among hybrids; stem height, ear height and ear length. In physical properties, range of kernel sugar content among used hybrids appeared 16.1 to 13.0brix(%). CNU08H-15, CNU08H-35 and CNU08H-h39 among these were highly appeared as 15 above and pericarp thickness of Yeonongchal was very thick as $46.0{\mu}m$, while CNU08H-39 among hybrids showed the thinnest as $23.0{\mu}m$ compared to other hybrids. Protein content as a indicator of table quality was the highest in Ilmichal among hybrids, while that of CNU08H-39 was the lowest, while amylopectin content was the highest as 94.5%, From experimental results, Daehakchal Gold 1, CNU08H-h121 and CNU08H-39 including check Yeonyoungchal were highly evaluated as new hybrid in thinner pericarp, high amylopectin and chewiness.

Effect of Olive Oil Substitution Ratio on Quality Characteristics of Low-fat Pork Patty (올리브유 대체 비율이 저지방 돈육 패티의 품질 특성에 미치는 영향)

  • Lee, Si-Hyung;Choi, Young-Joon;Lee, Kyoung-Sook;Jung, In-Chul;Lee, Kyung-Soo;Choi, Gang-Won
    • Journal of Life Science
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    • v.30 no.7
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    • pp.606-613
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    • 2020
  • This study investigated the effect of olive oil substitution ratio on physicochemical quality of pork patty. Five treatments were performed as follows: control (T0, 20% pork fat), T1 (pork fat 15% and olive oil gel 5%), T2 (pork fat 10% and olive oil gel 10%), T3 (pork fat 5% and olive oil gel 15%), and T4 (olive oil gel 20%). The moisture increased and fat amount was decreased in proportion to olive oil substitution ratio. The L* and a* values were highest levels in raw and cooked pork patty of T0, and the b* value was highly enhanced in of cooked pork patty of T4. The water holding capacity, moisture and fat retention were significantly increased, and the cooking loss, diameter reduction and shrinkage ratio were decreased by olive oil substitution ratio. The hardness, springiness and chewiness showed the highest level in T4, and the cohesiveness and gumminess were highest in T0. The reduction ratio of cholesterol in T1, T2, T3 and T4 were 13.8%, 21.6%, 34.5% and 49.0%, respectively, indicating that the content was lowest level in T4. The palmitic acid was the most abundant saturated fatty acid, and the oleic acid was the most abundant unsaturated fatty acid. The unsaturated fatty acid of pork patty was increased in proportion to olive oil substitution ratio. Therefore, the olive oil gel substitution of low-fat pork patty results in a positive effect on the physicochemical qualities due to reduced cholesterol and saturated fatty acids.

Physicochemical properties of Salvia miltiorrhiza Bunge following treatment with enzymes (효소 처리에 따른 단삼 추출물의 이화학적 특성)

  • Kim, Sun-Hwa;Hwang, In-Wook;Chung, Shin-Kyo;Seo, Young-Jin;Kim, Jong-Soo;Jeong, Yong-Jin;Kim, Mi-Yeon
    • Food Science and Preservation
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    • v.22 no.5
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    • pp.699-707
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    • 2015
  • To improve the utilization of the domestic plant Salvia miltiorrhiza Bunge (Danshen), this study investigated changes in the physicochemical qualities of Danshen extracts obtained from low-temperature extraction using the enzymes amylase, cellulase, pectinase, and protease. Changes in the yield, pH, sugar content, and chromaticity were investigated. The changes were found to be highest in the amylase-treated extract with the following values: yield, 58.3%; pH, 6.04; sugar content, $5.97^{\circ}Brix$. With regard to antioxidant properties, Danshen extracts treated with amylase showed the highest DPPH and ABTS scavenging activities of 84.25% and 74.11% at 55 ppm. The total phenolic compound content was highest in the group subjected to enzyme treatment at $60^{\circ}C$. The salvianolic acid B level of the Danshen extract was the highest in the amylase-treated group, with a value of 3,002.6 mg/100 g. Cryptotanshinone level was the highest in the amylase- and protease-treated group with a value of 3.8 mg/100 g. Tanshinone I was the highest in the protease-treated group, with a value of 14.2 mg/100 g. The results showed that the indicator components of Danshen were detected as stable in the extracts after using amylase for low-temperature extraction; therefore, it would be possible to use Danshen industrially as a functional ingredient through mass production. Furthermore, the enzyme-treatment extraction could be utilized for a variety of natural products.

Effects of gamma irradiation on the microbiological and general quality characteristics of fresh yam juice (감마선 조사 마(Yam)즙의 미생물학적 및 일반품질 특성)

  • Song, Hyun-Pa;Kim, Bok-Duck;Shin, Eun-Hye;Song, Du-Sup;Lee, Hyun-Ja;Kim, Dong-Ho
    • Food Science and Preservation
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    • v.17 no.4
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    • pp.494-499
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    • 2010
  • Pasteurization by radiation was performed to improve the microbiological quality of fresh yam juice. Samples were irradiated at doses of up to 5 kGy and microbiological, physicochemical, and sensory qualities were investigated during storage at 5oC for 8 days. Total aerobic bacterial, coliform bacterial, and yeast and mold counts in pre-irradiation samples were 7.09, 6.91, and 3.42 log CFU/g, respectively. Total aerobic bacterial and coliform counts fell significantly, in a dose-dependent manner, after irradiation, and these organisms were completely eliminated after 1 day of storage when 3 kGy or 5 kGy of radiation was applied. Yeast and molds were eliminated by irradiation at 3 kGy. Irradiation reduced sample viscosity. The $L^*$ value decreased after irradiation, whereas the $b^*$ value rose. Sensory evaluation testing revealed no significant difference between control samples and those irradiated with 1 kGy, except in color and texture, but sensory scores fell when irradiation of 3 kGy or over was employed, except in the taste domain. The results indicate that gamma irradiation with 1 kGy is effective to ensure the microbiological safety of fresh yam juice, without significant alteration in sensory characteristics, although further work should seek to reduce the detrimental effects of irradiation.

Study on Temporal Decay Characteristics of Naturally Occurring Radionuclides in Groudwater in Two Mica Granite Area (복운모화강암지역 지하수 중 자연방사성 물질의 경시적 붕괴특성 연구)

  • Kim, Moon Su;Kim, Tae Seung;Kim, Hyun Koo;Kim, Dong Su;Jeong, Do Hwan;Ju, Byoung Kyu;Hong, Jung Ki;Kim, Hye Jin;Park, Sun Hwa;Jeong, Chan Ho;Cho, Byong Wook;Han, Jin Seok
    • Journal of Soil and Groundwater Environment
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    • v.18 no.4
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    • pp.19-31
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    • 2013
  • To figure out the decay characteristics of naturally occurring radionuclides, eight sampled groundwaters from a monitoring borehole having high levels of uranium and radon concentrations in a two mica granitic area have analyzed by liquid scintillation counters (LSC) for over 1 year. In December 2011, three groundwater samples (DJ1, DJ2, DJ3) were obtained from each aquifer system located at -20 m, -40 m, -60 m of the monitoring borehole below the ground surface, respectively. Five samples (DJ4, DJ5, DJ6, DJ7, DJ8) were additionally gained from each aquifer positioned -20 m, -40 m, -60 m, -100 m, -105 m of the borehole in February 2012, respectively. Temporal variation characteristics of uranium and radon concentrations have showed over maximum 2.1 times and 1.4 times fluctuations of the values in the same sampling intervals over time, respectively. The intervals of -40 m and -105 m in the borehole have the highest values of uranium and radon concentrations, respectively. This may imply that the concentrations of naturally occurring radionuclides such as uranium and radon in groundwater have been changed over time and indicate that the qualities of groundwaters from the aquifers developed at each interval in the borehole are different each other. This discrepancy, moreover, could be caused by behaviour differences between uranium which is in ionic status having a half life of 4.6 billion years and is transported along with the flowing groundwater, and radon which is in gaseous status having a 3.82 day's half life in the aquifer systems. Physicochemical characteristics of groundwaters from the aquifer systems could be identified by the results of the on-situ measuring items such as pH and Eh, and the major ionic contents. The CPM values of eight groundwater samples analysed by LSC over one year have shown not to follow the theoretical decay curve of the radon. The CPM values of the samples have ranged from 2 to 7.5 after it had passed two months when the theoretical CPM values of the radon started zero since the initial analysis. Alpha and beta particle spectrums have shown the peaks of radium-226, however they have not revealed any peaks of radon and it's daughter products such as polonium-218 and 214, bismuth-214 for the late stage of the analysis. This implies that the groundwater from the borehole may contain radium-226 having a half life of 1,600 years which decays continuously.

Trend and Further Research of Rice Quality Evaluation (쌀의 품질평가 현황과 금후 연구방향)

  • Son, Jong-Rok;Kim, Jae-Hyun;Lee, Jung-Il;Youn, Young-Hwan;Kim, Jae-Kyu;Hwang, Hung-Goo;Moon, Hun-Pal
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47
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    • pp.33-54
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    • 2002
  • Rice quality is much dependent on the pre-and post harvest management. There are many parameters which influence rice or cooked rice qualitys such as cultivars, climate, soil, harvest time, drying, milling, storage, safety, nutritive value, taste, marketing, eating, cooking conditions, and each nations' food culture. Thus, vice evaluation might not be carried out by only some parameters. Physicochemical evaluation of rice deals with amy-lose content, gelatinizing property, and its relation with taste. The amylose content of good vice in Korea is defined at 17 to 20%. Other parameters considered are as follows; ratio of protein body-1 per total protein amount in relation to taste, and oleic/linoleic acid ratio in relation to storage safety. The rice higher Mg/K ratio is considered as high quality. The optimum value is over 1.5 to 1.6. It was reported that the contents of oligosaccharide, glutamic acid or its derivatives and its proportionalities have high corelation with the taste of rice. Major aromatic compounds in rice have been known as hexanal, acetone, pentanal, butanal, octanal, and heptanal. Recently, it was found that muco-polysaccharides are solubilized during cooking. Cooked rice surface is coated by the muco-polysaccharide. The muco-polysaccharide aye contributing to the consistency and collecting free amino acids and vitamins. Thus, these parameters might be regarded as important items for quality and taste evaluation of rice. Ingredients of rice related with the taste are not confined to the total rice grain. In the internal kernel, starch is main component but nitrogen and mineral compounds are localized at the external kernel. The ingredients related with taste are contained in 91 to 86% part of the outside kernel. For safety that is considered an important evaluation item of rice quality, each residual tolerance limit for agricultural chemicals must be adopted in our country. During drying, rice quality can decline by the reasons of high drying temperature, overdrying, and rapid drying. These result in cracked grain or decolored kernel. Intrinsic enzymes react partially during the rice storage. Because of these enzymes, starch, lipid, or protein can be slowly degraded, resulting in the decline of appearance quality, occurrence of aging aroma, and increased hardness of cooked rice. Milling conditions concerned with quality are paddy quality, milling method, and milling machines. To produce high quality rice, head rice must contain over three fourths of the normal rice kernels, and broken, damaged, colored, and immature kernels must be eliminated. In addition to milling equipment, color sorter and length grader must be installed for the production of such rice. Head rice was examined using the 45 brand rices circulating in Korea, Japan, America, Australia, and China. It was found that the head rice rate of brand rice in our country was approximately 57.4% and 80-86% in foreign countries. In order to develop a rice quality evaluation system, evaluation of technics must be further developed : more detailed measure of qualities, search for taste-related components, creation and grade classification of quality evaluation factors at each management stage of treatment after harvest, evaluation of rice as food material as well as for rice cooking, and method development for simple evaluation and establishment of equation for palatability. On policy concerns, the following must be conducted : development of price discrimination in conformity to rice cultivar and grade under the basis of quality evaluation method, fixation of head rice branding, and introduction of low temperature circulation.

Effect of supercooling on the storage stability of rapidly frozen-thawed pork loins (과냉각 온도가 급속냉동-해동 처리된 돈육 등심의 저장성에 미치는 영향)

  • Choi, Eun Ji;Park, Hae Woong;Chung, Young Bae;Kim, Jin Se;Park, Seok Ho;Chun, Ho Hyun
    • Food Science and Preservation
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    • v.24 no.2
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    • pp.168-180
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    • 2017
  • This study was performed to determine the rapid thawing method for reducing the thawing time of frozen pork loins and to examine the effects of supercooling on the microbiological, physicochemical, and sensory qualities of fresh and frozen-thawed pork during storage at -1.5, 4, and $15^{\circ}C$. Forced-air thawing at $4^{\circ}C$ was the most time-consuming process, whereas radio frequency thawing time was the shortest by dielectric heating. The supercooling storage temperature was chosen to be $-1.5^{\circ}C$ because microstructural damages were not observed in the pork sample after cooling at $-1.5^{\circ}C$ for 24 h. Fresh or frozen-thawed pork loins stored at $-1.5^{\circ}C$ had lower drip loss and total volatile base nitrogen, thiobarbituric acid-reactive substance, and Hunter b* levels than loins stored at 4 and $15^{\circ}C$. In addition, the least degree of increase in preexisting microorganisms counts of the fresh or frozen-thawed pork loin samples was obtained during supercooled storage at $-1.5^{\circ}C$. Sensory quality results of fresh and frozen-thawed pork loin samples stored at $-1.5^{\circ}C$ showed higher scores than the samples stored at 4 and $15^{\circ}C$. These data indicate that supercooling at $-1.5^{\circ}C$ in the meat processing industry would be effective for maintaining the quality of pork meats without ice crystal nucleation and formation.

Comparison of the Quality Characteristics and Antioxidant Activities of the Commercial Black Garlic and Lab-Prepared Fermented and Aged Black Garlic (시판 흑마늘과 제조 흑마늘의 이화학적 품질 및 항산화 특성 비교)

  • You, Bo-Ram;Kim, Hye-Ran;Kim, Min-Ji;Kim, Mee-Ree
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.3
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    • pp.366-371
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    • 2011
  • This study was carried out to investigate the quality characteristics and antioxidant activities of the commercial black garlic (NHBG: Namhae black garlic, USBG: Uiseng black garlic, CNBG: Changnyung black garlic) and FABG (fermented and aged black garlic). The sugar contents of NHBG, USBG, CNBG, and FABG were 42.7, 42.7, 56.7 and $54.7^{\circ}Brix$, respectively, whereas the reducing sugar contents were 15.0, 16.0, 23.5 and 25.9%. The pH decreased with the processing of the fermented aged black garlic, whereas the acidity increased. In addition, the thiol content was the highest in fermented and aged black garlic (p<0.05). The antioxidant activities by DPPH and hydroxyl radical scavenging activity of fermented and aged black garlic were much higher than those of the other samples. Total phenol contents of NHBG, USBG, CNBG and FABG were 0.64 mg/mL, 0.60 mg/mL, 0.68 mg/mL and 0.72 mg/mL, respectively. ABTS radical scavenging activity of fermented and aged black garlic were much higher then those of the other samples. FRAP values of NHBG, USBG, CNBG, and FABG were 1.7 mg/mL, 1.4 mg/mL, 1.7 mg/mL and 1.9 mg/mL, respectively. Based on these results, it is suggested that the fermented and aged black garlic was appropriate for good qualities in terms of both physicochemical and antioxidative activities.

Quality Characteristics of Pleurotus eryngii Cultivated with Different Wavelength of LED Lights (LED광의 파장을 달리하여 재배한 새송이버섯의 품질특성)

  • Kim, Do-Hee;Choi, Hye-Jin;Jo, Woo-Sik;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.19 no.3
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    • pp.354-360
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    • 2012
  • The effect of the wavelength of the light emitted by the light-emitting diode (LED) on the growth characteristics and physicochemical and sensory qualities of Pleurotus eryngii were investigated. Pleurotus eryngii were grown under different light sources: blue light (450 nm), red light (650 nm), green light (525 nm), UV-A (365 nm), and mixed light ($B^*R$, $B^*G$, $R^*G$, $B^*R^*G^*UV-A$). The quantity of LED light was set up at 50% (LED: 64.9-108.0 $pmolm-2{\cdot}s-1$;fluorescentlight:11.7lux). Fluorescent light was used as control. There were no significant differences in the flesh firmness. In the case of the Pleurotuseryngii cultivated under red, green, and mixed light ($R^*G$), the color of the pileus and the length of the stipe were similar to those of the control group. The sensory scores were not significantly different between the LED lights (red, green, and $R^*G$) and the control. Among the three LED light conditions, the sample cultivated under red light recorded the highest score. The samples under UV-A, blue, and mixed light ($B^*R$, $B^*G$, $B^*R^*G^*U$) had a dark pileus color and had a short stipe. These results showed that the wavelength of LED light affected the growth and quality characteristics of Pleurotus eryngii, and that using red LED light is preferable for the cultivation of Pleurotus eryngii with better quality.