• Title/Summary/Keyword: Physicochemical changes

Search Result 918, Processing Time 0.022 seconds

A study on manufacturing of red ginseng Makgeolli using the red ginseng starch and changes of physicochemical components of red ginseng Makgeolli during storage periods (홍삼 전분을 이용한 홍삼막걸리의 제조 및 이화학적 성분 변화)

  • Lee, Hwan;Kim, Yeong-Su;Kim, Do-Yeon;Kim, So-Young;Lee, Wan-Kyu;Lee, Sang-Myeong;Park, Jong-Dae;Shon, Mi-Yae
    • Food Science and Preservation
    • /
    • v.22 no.3
    • /
    • pp.369-376
    • /
    • 2015
  • This study was performed to develop the maufacturing processes of Makgeolli using red ginseng starch (RGS). After the fermentation of RGS with koji, nuruk, and yeast, the different temperature effects on the number of the yeast cells, the content of organic acid, free sugars, and total acid, and pH were investigated. There were no changes in the composition of the yeast cell number and content of organic acid amd during 20 days at $4^{\circ}C$. The content of free sugars (sucrose, glucose and mannose) and the pH value of red ginseng Makgeolli decreased during storage at $4^{\circ}C$. This meant that the total acid content and pH value increased after organic acid was produced from fermentation. Therefore, red ginseng Makgeolli is highly acidic and sour. Since high acidity helps improve storage conditions, so this developed red ginseng Makgeolli is considered safe for consumption. Furthermore, the total content of ginsenoside was 2.47 mg/mL, which was differentiate Makgeolli using red ginseng starch, with others. Therefore, new red ginseng Makgeolli is rich in organic acid, free sugars, and ginsenoside. As a result, its storage, taste, and flavor improved.

Quality Characteristics of Pound Cake with Citrus mandarin Powder during Storage (감귤 분말을 첨가한 파운드케이크의 저장 중 품질 특성)

  • Park, Yeong-Sun;Shin, Sol;Shin, Gil-Man
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.18 no.6
    • /
    • pp.1022-1031
    • /
    • 2008
  • Pound cakes were prepared with Citrus mandarin powder(CMP) cultivated in JeJu Island, Korea. The impact of CMP amount level, which was incorporated into wheat flour by the ration of 0, 5, 10, 15, and 20% based on a flour weight, on the rheology and sensory profile of the pound cakes was measured. Moisture content of 13.70%, crude protein 5.12%, crude lipid 1.30%, crud ash 1.92%, respectively. Also evaluation was performed on the changes in physicochemical properties of the pound cakes during storage at 4 and $30^{\circ}C$. According to the amylogram, gelatinization temperature of the control dough was $63.35^{\circ}C$ and those of the dough with CMP were $63.85{\sim}66.55^{\circ}C$. Maximum viscosity of the dough was 686 B.U in the control, those were 575 B.U, 553 B.U, 504 B.U and 401 B.U in the dough with 5, 10, 15, and 20% CMP, respectively. The retrogradation degree(setback value) of CMP dough was $31{\sim}57%$ lower than that of the control dough under the same conditions. Water holding capacity of pound cake was increased gradually in proportion to the amount of CMP. The CMP addition decreased the brightuess(L) of pound cakes but increased redness(a) and yellowness(b). Hardness of pound cakes was significantly increased by CMP addition, while springiness, adhesiveness and cohesiveness were decreased. Based on sensory evaluation, pound cakes added with CMP were not significantly different in color and texture, while that of 10% CMP was significantly high in taste, flavor, and overall preferences, compared to the control. pH of pound cake with CMP was decreased during storage, showing that pH of CMP samples was lower than the control. Titrated acidity of pound cake with CMP was increased rapidly from storage for 10 days, which the changes in degree was fast in accordance with CMP amount. The Hunter's color value of pound cake with CMP was decreased, as the storage time proceeded. In the samples prepared with CMP, the firmness, adhesiveness, gumminess and chewiness was increased as the storage time proceeded, while springiness and cohesiveness was decreased.

  • PDF

Changes of quality characteristics of Jicama (Pachyrhizus erosus) potato powder by drying methods (건조방법에 따른 히카마 감자분말의 품질특성 변화)

  • Choi, Sun-Il;Lee, Jin-Ha;Cho, Myoung-Lae;Shin, Gi-Hae;Kim, Jae-Min;Oh, Ji-Won;Jung, Tae-Dong;Rhee, Seong-Kap;Lee, Ok-Hwan
    • Food Science and Preservation
    • /
    • v.22 no.6
    • /
    • pp.915-919
    • /
    • 2015
  • This study was performed in order to provide basic data for predicting the usefulness of Jicama (Pachyrhizus erosus) as a food raw material. The changes in the physicochemical properties of freeze-dried and hot air-dried Jicama were investigated and analyzed. The moisture content of raw Jicama was 81.84%. The crude protein, crude fat, crude ash and carbohydrate content of hot air-dried Jicama powder were 2.85, 0.79, 7.93 and 88.44%, while those of freeze-dried Jicama powder were 3.93, 0.83, 7.92 and 87.32%, respectively on dry basis. Regarding the color values, the lightness of freeze-dried Jicama (92.86) was higher than that of the hot air-dried Jicama (88.01), whereas the redness (-0.67) and yellowness (3.21) of freeze-dried Jicama were lower than those of the hot air-dried Jicama (0.43) and (11.96), respectively. The brown index was lower in the freeze-dried Jicama (0.029) than in hot air-dried Jicama (0.107). The total sugar content showed no significant differences between freeze (46.49 mg/g) and hot air-dried Jicama (45.11 mg/g). Finally, the amylose content was higher in freeze-dried Jicama (5.66%) than in hot air-dried Jicama (6.63%).

Changes in the taste compounds of Kimchi with seafood added during its fermentation (수산물 김치의 발효과정 중 정미성분 변화)

  • Nam, Hyeon Gyu;Jang, Mi-Soon;Seo, Kyoung-Chun;Nam, Ki-Ho;Park, Hee-Yeon
    • Food Science and Preservation
    • /
    • v.20 no.3
    • /
    • pp.404-418
    • /
    • 2013
  • This study was conducted to investigate changes in the physicochemical properties (proximate compounds, reducing sugar, organic acid, ATP and related compounds, and free amino acid) of beachu kimchi (BK) with octopus, abalone, squid and webfoot octopus added during its storage at $4^{\circ}C$ for 35 days. The crude protein content of the seafood Kimchi, 1.98~3.41%, was higher than that of the BK. The organic acid level did not significantly differ in the four kinds of seafood during their fermentation, and their malate and succinate contents decreased while their lactate content increased. The levels of the ATP and related compound substances of the hypoxanthine contents were high but decreased during their fermentation. However, $3.40{\mu}mol/g$ of IMP was detected in the Kimchi with octopus added; $0.67{\mu}mol/g$ in the Kimchi with abalone added; and $1.80{\mu}mol/g$ in the Kimchi with squid added after they were fermented for 21 days, but the same were not detected in the BK. The taurine and ${\gamma}$-amino-n-butyric acid contents of the free amino acids in the seafood Kimchi were approximately two to 10 times and 1.5 to three times higher than in the BK, respectively.

Occurrence and Repression of Off-Odor in Cooked Rice during Storage under Low Temperature Warming Condition of Electric Rice Cooker (전기밥솥으로 저온보온한 쌀밥의 이취 발생 및 억제)

  • Park, Seok-Kyu;Ko, Yong-Duck;Cho, Young-Sook;Shon, Mi-Yae;Seo, Kwon-Il
    • Korean Journal of Food Science and Technology
    • /
    • v.29 no.5
    • /
    • pp.919-924
    • /
    • 1997
  • The changes in physicochemical properties of cooked rice stored in an electric rice cooker at different temperature (63, 66, 69 and $72^{\circ}C$) were investigated. The growth of thermophilic bacteria was gradually increased in all samples with storage time up to 6 hours and increased rapidly afterward. The bacterial growth rate was higher during storage at low temperature than at high temperature, and the bacterial number generally reached the maximum at 18 hours of the storage. The number of bacteria in sample stored at $63^{\circ}C$ was increased to $10^6$ CFU/g after storage for 6 hours. The heat treatment at 6 hours of storage decreased the bacterial number to $10^5 $ CFU/g at 8 hours of storage. Bacterial number was gradually increased with storage time after the first heat treatment. When the sample was reheated after 8 hours of storage, the bacterial number was reduced to the level at which off-odor was not detected after storage for 24 hours. During the storage, moisture content of heat-treated sample was lower than that of sample stored at $63^{\circ}C$ but higher than that of sample stored at $72^{\circ}C$. The L value of heat-treated sample was higher than that of the sample stored at $72^{\circ}C$, but lower than that of the sample stored at $63^{\circ}C$. The b value showed an opposite trend to the L value with regard to the storage temperature. Changes in texture were not remarkable during the storage for the sample heat-treated and stored at low temperature. The occurrence of off-odor and browning was depressed in the heat-treated sample, and the texture and overall eating quality were more acceptable than the samples stored at low temperature.

  • PDF

Effect of Powder of Stevia rebaudiana Leaves against Quality Characteristics during Salting of Rice Bran Danmooji (쌀겨단무지의 절임 중 품질 특성의 변화에 대한 스테비아 잎 분말 첨가의 영향)

  • Kim, Yong-Suk;Lee, Sun-Kyu;Jeong, Do-Yeong;Yang, Eun-Jin;Shin, Dong-Hwa
    • Food Science and Preservation
    • /
    • v.14 no.5
    • /
    • pp.497-503
    • /
    • 2007
  • In order to develop a new rice bran danmooji, changes in physicochemical characteristics and texture of danmooji treated with rice bran, Stevia rebaudiana Bertoni leaf powder, succinic acid, or yeast extract were investigated during salting for 90 days. The PH of rice bran danmooji decreased from PH6.41 initially to pH 4.09 (control group), pH 4.10 (S. rebaudiana treatment S1), pH 3.84 (S. rebaudiana + succinic acid treatment S2), and pH 3.90 (S. rebaudiana+succinic acid+yeast extract treatment S3) after 90 days of salting. At this time, the salinities of rice bran danmooji of the S1, S52, and S3 groups were 2.32%, 1.94% and 2.15% respectively. The hardness of all groups decreased rapidly in the first 30 days of salting, and thereafter showed no changes. After 90 days of salting, the hardness of all groups was $1,186-1,368\;g/cm^2$ with no significant differences between groups. Redness, the a value, of the S2 and S3 groups treated with succinic acid, was lower than that of S3, whereas yellowness, the b value, of S3 treated with succinic acid and yeast extract was the highest of the three groups. Sensory evaluation of rice bran danmooji after 90 days of salting resulted in S3 attaining the highest scores for flavor, taste, texture, and overall acceptability. These results indicate nut high-quality rice bran danmooji may be prepared by addition of S. rebaudiana leaf powder, succinic acid and yeast extract to rice bran.

Changes of Indicative Substances According to Heat Treatment of Milk (우유의 가열처리에 따른 지표물질의 변화)

  • 김경미;홍윤호;이용규
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.21 no.4
    • /
    • pp.390-397
    • /
    • 1992
  • This study was carried out to analyze the physicochemical properties of bovine milks, which were heated with LTLT, HTST, UHT pasteurization and UHT sterilization methods and to compare the heat intensity among the heating methods and samples. The mean HMF values per liter milk were measured as 0.66~1.62 $\mu$M (LTLT), 0.9~1.78$\mu$M (HTST), 3.53$\mu$M(UHT pasteurized) and 7.43~8.97$\mu$M (UHT sterilized) in samples, re- sportively. The available Iysine contents per 100ml milk showed 293.2 mg (Raw), 289.2~291.2 mg (LTLT), 298.4~292.4mg (HTST), 272.4~261.6mg (UHT pasteurized) and 279.0mg (UHT sterilized), respectively. The rates of whey protein denaturation were 9.5~11.4% (LTLT), 9.5~17.1% (HTST), 89.3~95% (UHT pas-tsterilized) and 62.7% (UHT sterilized), respectively. The contents of SH groups per g protein were determined as 2.86$\mu$M (Raw) and 2.95~3.15$\mu$M (LTLT), 3.08~3.18$\mu$M (HTST), 3.26~3.42$\mu$M (UHT Pasteurized) and 3. 36$\mu$M (UHT sterilized), respectively, The SS groups Contents per g protein were 28.93$\mu$M (Raw), 25.72~26. 51 $\mu$M (LTLT), 26.93~26.79$\mu$M (HTST), 23.65~23.04 $\mu$M (UHT pasteurized) and 24.69$\mu$M (UHT sterilized), respectively. The ascorbic acid contents per liter milk were measured 6.05mg (Raw), 1.47~1.65mg (LTLT), 2.50~3.85mg (HTST), 2.87~3.69mg (UHT pasteurized) and 4.50mg (UHT sterilized). The changes of some in-dices in milk samples depend on the heating temperature and time ; the HMF values, SH groups, whey protein denaturation rates increased, while the available lysine contents and SS groups decreased in LTLT, HTST, UHT pasteurized and UHT sterilized milks. No remarkable differences were found in heating indicators between LTLT and UHT milks.

  • PDF

Changes in quality characteristics of sliced garlic with different freezing conditions during storage (냉동조건에 따른 편마늘의 냉동저장 중 품질변화)

  • Kim, Seok-Young;Kim, Hee-Sun;Kim, Jin-Se;Han, Gwi-Jung
    • Food Science and Preservation
    • /
    • v.24 no.6
    • /
    • pp.746-757
    • /
    • 2017
  • This study was performed to evaluate the effect of different freezing conditions and storage periods on physicochemical and microbial characteristics of garlic. Garlics were washed, dried, sliced to 0.3 cm then packed in LDPE+LLDPE film bags. They were treated with still-air freezing at $-20^{\circ}C$ (SAF20), $-40^{\circ}C$ (SAF40) and immersed-liquid freezing at $-40^{\circ}C$ (ILF40). Frozen garlics were stored under frozen storage conditions for 7 months at $-20^{\circ}C$ and quality characteristics were measured monthly during the frozen storage. Freezing rate of garlic was the fastest in ILF 40 (10 min), SAF40 (40 min) and SAF20 (1,600 min) sequentially. In ILF40, drip loss, cutting force, total aerobic bacteria count and pH were the lowest, whereas pyruvic acid and allicin content were the highest (p<0.05) during frozen storage, these results were the most similar characteristics with the fresh garlic. During frozen storage, drip loss, color difference and total organic acid content were significantly fluctuated in SAF20 (p<0.05), while they were not changed in ILF40. Overall, total aerobic bacteria count and pH decreased, cutting force, pyruvic acid and allicin content remained unchanged in all groups. In conclusion, the optimal freezing conditions for garlic with the least quality changes was considered to be ILF40 (immersed liquid freezing), keeping quality characteristics up to 7 months by freezing storage.

Changes in Physio-Chemical Properties of Deer Meat Cold Storage at 4°C and -2°C (냉장저장중 사슴고기의 이화화적 성질의 변화)

  • Shin Teak-soon;Kang Han-seok;Kim Seon-ku;Lee Kil-wang
    • Journal of Life Science
    • /
    • v.15 no.4 s.71
    • /
    • pp.522-527
    • /
    • 2005
  • A total of 5 female elk dEER $(220kg\pm10kg)$ were included in a study on the changes in physicochemical properties of deer meat during storage at $4^{\circ}C\;and\;-2^{\circ}C$. The deer was exposed to normal pre-slaughter handling and put under anesthesia before slaughtered. The loin and leg cuts were deboned from the carcass after 24hrs slaughter. The samples weighing approximately 300g were packaged using wrap packaging and stored for 3, 7, 11 and 15 days at $4^{\circ}C\;and\;-2^{\circ}C$. Water-holding capacity was decreased with increasing storage days at $4^{\circ}C\;or\;-2^{\circ}C$, respectively The deer meats kept at $-2^{\circ}C$ showed lower TBARS value than the meats kept at $4^{\circ}C$, and it was possible to extend the storage period of the meats. VBN values of the meats kept at $4^{\circ}C\;and\;-2^{\circ}C$ showed as edible values after storage for 15 days, although there were no significant differences among the storage temperature. pH values of loin and leg tended to be increased with the passage of storage time, and the values of the meats kept at $-2^{\circ}C$ was lower than that at $4^{\circ}C$. The change of meat softness was remarkable at $4^{\circ}C$, and the change at $-2^{\circ}C$ was slow. Therefore, it was effective to extend the storage period when the meats were kept at $-2^{\circ}C$. Color of the meats kept at $-2^{\circ}C$ was darker than that at $4^{\circ}C$, the index of red color was higher for the meats kept at $-2^{\circ}C$, and yellow color of meats kept at $-2^{\circ}C$ was more rapidly changed with the passage of storage time.

Changes in Growing Period and Productivity under Double Cropping of Spring Potato and Summer Cereals in Paddy Fields of Southern Korea (남부지역 논에서 봄감자와 하작물 이모작에 따른 생육기간 및 생산성 변화)

  • Seo, Jong-Ho;Hwang, Chung-Dong;Choi, Weon-Young;Bae, Hyeon-Kyung;Kim, Sang-Yeol;Oh, Seong-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.64 no.4
    • /
    • pp.459-468
    • /
    • 2019
  • Changes in growing periods and productivities of crops under double cropping of potato-rice, potato-soybean and potato-maize, were investigated at the Paddy Experimental Fields in Miryang City from 2015 to 2018. Spring potatoes planted in early March showed a yield of 2.1-2.3 ton/10a and a period of 90 days. In double cropping, growing period of rice, soybean, and maize was about 130, 125 and 115 days, respectively. The potato yield obtained was as much as 616, 330 and 815 kg/10a under double cropping with rice, soybean and maize, respectively. It is beneficial to sow the spring potatoes as early as possible to increase the yield and to secure the growing period of sequential crops. The introduction of summer medium-late variety grain crops into double cropping of spring potato and rice as well as into double cropping of spring potato and soybean/maize, was possible because of no sowing in the fall and plants were able to reach the heading growth stage before the safe heading limit of rice in particular. In the case of maize, the growth period was different according to the change in temperature over the year. The introduction of upland crops such as soybeans and maize instead of rice improved soil physicochemical properties in a short period of time, contributing to the increase of spring potato yields, but there was also a risk of damage by successive cropping for more than three years. Spring potato-maize showed higher yield in terms of starch production, and spring potato-soybean was found to be advantageous for net income.