• Title/Summary/Keyword: Physicochemical property

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Changes in Physicochemical Properties of Rice Starch Processed by Ultra-Fine Pulverization

  • Han, Myung-Ryun;Chang, Moon-Jeong;Kim, Myung-Hwan
    • Journal of Applied Biological Chemistry
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    • v.50 no.4
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    • pp.234-238
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    • 2007
  • The effects of ultra-fine pulverization on the physicochemical properties of rice starch (RS) were investigated using a high impact planetary mill. After pulverization, RVA characteristics, peak viscosity, break down, and set back values of RS decreased from 274.75 to 9.42 RVU, 214.46 to 6.17 RVU, and 87.80 to 17.00 RVU, respectively. The pasting properties also changed significantly. X-Ray diffractogram revealed RS had four A-type peaks, which disappeared after pulverization. The peak temperature and gelatinization enthalpy of RS using differential scanning calorimetry (DSC) were 13.99 J/g at $75.14^{\circ}C$, whereas the pulverized RS (PRS) had two peaks, 0.13 J/g at $63.88^{\circ}C$ and 1.23 J/g at $101.24^{\circ}C$. DSC measurement showed the retrogradation degree of PRS was lower than that of RS after storage at 4 and $25^{\circ}C$. The enzymatic (${\alpha}$-amylase) digestibilities of RS and PRS were 72.7 and 77.3%, respectively.

Changes in Physicochemical Properties and Microorganisms during the Storage of Kimchi Stew저s Sauce (김치찌개용 양념의 저장 및 품질특성의 변화)

  • 권혜순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.107-112
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    • 1999
  • Physicochemical properties and microflora of kimchi stew's sauce were investigated during 6 months at 13oC, 27oC and 37oC to study the changes of its quality. The final pH values in the sauce showed a slight decrease to 4.46, 4.38 and 4.21 during storage at 13oC, 27oC and 37oC, respectively. Color(L, a, b values), salinity, moisture and Aw in the sauce were decreased during storage. However, the values of brix and browning, and the amounts of total sugar, crude protein and crude fat in the sauce were increased during storage. All the reactions occurred more rapidly in the samples stored at 37oC than those stored at 27oC and 13oC. The viable cell counts of aerobic bacteria in the sauce were changed remarkably during storage, but viable cell counts of lactic acid bacteria were decreased. Yeast, mold and E. coli were not found in the above temperatures during storage. Regression analysis between sensory scores and quality characteristics showed that the ΔE value was a major quality index for the deterioration of kimchi stew's sauce. The shelf lives of sauces at 13oC, 27oC, 37oC were estimated to be 24 months, 6 months and 6 months, respectively.

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Changes in Physicochemical Properties of Kochujang added with Onion Powder (양파분말을 첨가한 고추장의 이화학적 특성 변화)

  • 서권일;김용택;조영숙;손미예;이상원
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.5
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    • pp.425-430
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    • 2000
  • Physicochemical properties of Kochujang(OK) added onion powder (OK ) were Investigated duringstorage at 20"C The pH value of Kochujang tended to decrease by condition of storage. Initial pH value of OK was significantly lower than that of control, but the difference of pH value was getting smaller during the storage period. In the Process of 90 days storage period, the pH value of OK containing 8 and 10% of onion powder was higher than control. Salt content was lower in OK than in control as the onion content was higher No changes in salt content were observed during the storage process. Reducing sugar was higher in OK than in control, and Its concentration was increased with onion content. Amino acid nitrogen content which was slightly higher in OK than in control increased during 45 days of storage period and tended to decrease afterward. In the sensory attribute data of Kochujang after 3 months of storage period, OK had higher scores in sweetness, color, flavor, and overall acceptability than control, especially the OK with 10% onion powder had the highest scores.scores.

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Physicochemical Properties of Sodium Hypochlorite Oxidized Potato Starch (Sodium Hypochlorite로 산화된 감자 전분의 이화학적 특성)

  • 김미라
    • Journal of the East Asian Society of Dietary Life
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    • v.7 no.3
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    • pp.315-324
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    • 1997
  • Physicochemical properties of potato starches oxidized with sodium hypochlorite containing 1.5, 3.0, 4.5, and 6.0% active Cl/g starch at pH 7.0 were examined. Carboxyl group contents of oxidized potato starches were proportional to active chlorine concentration in use and water binding capacity, alkali number, and solubility increased with increasing the degree of oxidation. Blue value and iodine binding property indicated the change of amylose structure by the oxidation. Gelatinization trends obtained from transmittance and DSC thermograms showed that gelatinization temperature was lower as starch was oxidized higher. X-ray diffraction patterns and scanning electron micrographs implied oxidation might occur on the surface amorphous regions of starch granule.

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Comparison on Physicochemical Properties and Antioxidant Activities of Commonly Consumed Coffees at Coffee Shops in Seoul Downtown (서울 시내 커피전문점에서 판매되는 커피의 이화학적 특성 및 항산화성 비교)

  • 서한석;김수희;황인경
    • Korean journal of food and cookery science
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    • v.19 no.5
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    • pp.624-630
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    • 2003
  • The physicochemical properties and antioxidant activities of commonly consumed espresso and regular coffees, at coffee shops in downtown Seoul, were investigated. Moreover, the characteristics between chain type coffee shops and owner shops were compared using t-tests. The serving temperature and volume of espresso were lower than those for regular coffees. Whereas, the pH and total acidity of espresso were higher than those for regular coffees. Coffees from chain shops, in particular, had a significantly higher pH and lower total acidity than those from owner shops. The L, a and b values of the regular coffees were higher than those of the espresso coffees. With the exception of the a value of regular coffees, all the color values of the coffees from owner shops were higher than those from the chain shops. The intensity of the brownness, soluble solid contents and total phenolic contents of the espresso coffees were about 7∼8, 8∼9 and 4 times higher, respectively, than those of regular coffees. In addition, the free radical scavenging capacities and antioxidant activities of the espresso coffees, using a chemiluminescence assay, were higher than those of regular coffees. Espresso coffees from chain shops, especially, had higher activities of free radical scavenging than those from owner shops. In conclusion, the characteristics of coffees from chain shops were significantly different from those from owner coffee shops.

Effect of Grape Skin on Physicochemical and Sensory Characteristics of Ground Pork Meat (포도과피 첨가가 분쇄돈육의 이화학적·관능적 특성에 미치는 영향)

  • Choi, Gang-Won;Lee, Jong-Wook
    • Korean journal of food and cookery science
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    • v.32 no.3
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    • pp.290-298
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    • 2016
  • Purpose: This study aimed to investigate the effect of grape skin on the physicochemical properties and sensory score of ground pork meat. Methods: Four types of ground pork were evaluated: T0 without grape skin, T1 with 0.3% grape skin, T2 with 0.7% grape skin, and T3 with 1.0% grape skin. Results: There was no significant group wise difference in VBN content, L-value, b-value, chemical composition of raw and cooked meat, cooking yield, water holding capacity, moisture retention, fat retention, hardness, springiness, cohesiveness, gumminess, chewiness, taste, texture, juiciness, or palatability. Total polyphenol content was highest in T3, and DPPH radical scavenging activity was highest in T2 and T3 (p<0.001). The pH was highest in T0, and was lowest in T3 (p<0.001). The a-value of T2 and T3 were significantly higher than that of T0 (p<0.05). Flavor was highest in T2 among samples (p<0.01). Conclusion: The study results suggest that grape skin may be a useful ingredient in ground pork meat in terms of antioxidant potential, color and flavor.

Physicochemical Properties of Bokbunja Jelly Containing Fermented Sea Tangle Saccharina japonica Powder (유산균 발효다시마(Saccharina japonica)를 첨가한 복분자 젤리의 이화학적 품질특성)

  • Choi, Ji-Won;Lee, Yeon-Ji;Moon, Soo-Kyung;Kim, Yong-Tae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.4
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    • pp.408-416
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    • 2022
  • This study investigated the physicochemical properties and physiological activities of jelly prepared from gelatin, sugar, bokbunja extract, and different amounts (0, 0.5, 1, 2 and 3%) of fermented sea tangle Saccharina japonica powder (FSP). The jelly moisture, pH, and sugar content slightly increased with increasing the FSP content. Hardness, springiness, gumminess, chewiness, and cohesiveness also increased with increasing FSP concentration. Jelly antioxidant activity did not change significantly with increasing FSP. In contrast, alcohol dehydrogenase and aldehyde dehydrogenase activities in the jellies increased significantly with increasing FSP concentration. β-secretase inhibitory activity in jellies also increased with increasing FSP concentration. Jellies containing 0.5 or 1% FSP achieved the highest overall sensory acceptance scores. Taken together, these data indicate that addition of FSP to jelly appears to improve its quality and physiological activities.

Rheological, Physicochemical, Microbiological, and Aroma Characteristics of Sour Creams Supplemented with Milk Protein Concentrate

  • Chan Won Seo;Nam Su Oh
    • Food Science of Animal Resources
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    • v.43 no.3
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    • pp.540-551
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    • 2023
  • Milk protein concentrate (MPC) is widely used to enhance the stability and texture of fermented dairy products. However, most research has focused on yogurt products, and the effects of MPC on sour cream characteristics remain unknown. Therefore, we investigated the effects of different MPC levels (0%, 1%, 2%, and 3% w/w) on the rheological, physicochemical, microbiological, and aroma characteristics of sour creams in this study. We found that MPC supplementation stimulated the growth of lactic acid bacteria (LAB) in sour creams, resulting in higher acidity than that in the control sample due to the lactic acid produced by LAB. Three aroma compounds, acetaldehyde, diacetyl, and acetoin, were detected in all sour cream samples. All sour creams showed shear-thinning behavior (n=0.41-0.50), and the addition of MPC led to an increase in the rheological parameters (ηa,50, K, G', and G"). In particular, sour cream with 3% MPC showed the best elastic property owing to the interaction between denatured whey protein and caseins. In addition, these protein interactions resulted in the formation of a gel network, which enhanced the water-holding capacity and improved the whey separation. These findings revealed that MPC can be used as a supplementary protein to improve the rheological and physicochemical characteristics of sour cream.

The Physicochemical Properties and Cooking Qualities of Barley (보리의 이화학적 특성과 취반성에 관한 연구)

  • 장학길;정일희
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.5
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    • pp.816-821
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    • 1994
  • The physicochemical properties and cooking qualities of six cultivars of covered barley, four malting barley and six naked barley were investigated. The 1, 000 kernel weight was heavier in the malting barley and ash content was the highest in covered barley. The varietal variation of amylose content was 17.7 to 20.2%. $\beta$-Glucan viscosity was generally lower in the malting barely, and varied greatly among barley cutivars with 2.16 to 8.47 cSt. The pearling rate was highest in naked barley with a mean of 75.5% and protein content of aw and pearled barely was significantly different with cultivars. In the cultivars tested, Doosan 8, Youngsan and Iri 5 showed the higher milling rate. Amylose patterns showed that the covered barley cultivars has lower gelatinization temperature and higher peak height and height at 50 $^{\circ}C$ than the malting and naked barley. The water absorptions were highest in covered barley cultivars , and lowest in naked barley cultivars. The soluble solid was highest in naked barley cultivars.

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Quality Characteristics of Satuma Mandarin According to Harvest Areas in Cheju (생산지역별 온주밀감의 품질특성)

  • 고정삼;송상철
    • Food Science and Preservation
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    • v.6 no.1
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    • pp.7-10
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    • 1999
  • Physicochemical properties of Satsuma mandarin(Citrus unshiu Marc. var. miyagawa) harvested in middle of November according to production areas of Cheju were investigated. Peel thickness of citrus fruits was ranged from 2.54mm to 3.13mm, and it was lower on fruits harvested in western areas than those of other areas in Cheju. Soluble solids were ranged from 10.1 to 12.0$^{\circ}$Brix, and it was lower on fruits harvested in southern areas. Acid contents of citrus juice were ranged from 1.28% to 1.42%, it was higher on fruits harvested in eastern areas, specific gravity of citrus fruits was ranged between 0.86 and 0.88. Flesh ratio was ranged from 75.1% to 77.6%, it was lower on fruits harvested in southern areas. Soluble solids, acid content and specific gravity harvested in southern areas of below 100m and over 150m sea level altitude were 11.8 and 11.2, 1.43% and 1.40%, 0.87 and 0.9, respectively. Fruits quality harvested in southern areas was better, compared to other harvest areas of Cheju.

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