• Title/Summary/Keyword: gelatinization characteristics

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A study on food scientific characteristics of the Job′s tears flour (율무전분의 조리과학적 특성에 관한 연구)

  • 신민자;안명수
    • Korean journal of food and cookery science
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    • v.3 no.2
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    • pp.59-67
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    • 1987
  • In order to make use of Job's tears widely, Job's tears starch was analyzed and determinded the contents of amylose, amylographical and other physicochemical properties. And also the yeast breads and rice cakes were made from flour and rice flours with various mixing ratios of Job's tears flour and then they were tested for suitability to preparation of bread and rice cake. 1. The starch contents of Job's tears showed 12~20%. Which was about one third of rice or waxyrice starch. But amounts of crude proteins, fats, and total ashes in Job's tears were higher than rice or waxyrice. Job' tears starch was composed of amylopectins only, and was similar to that of waxyrice starch. 2. Depends upon the Amylogram of each starch, initial gelatinization temperature of Job's tears starch was the highest among three starches of rice, waxyrice, and Job's tears. Maximum viscosity of Job's tears starch was 860BU, then it was about two times of rice starch viscosity. 3. By the sensory evaluation results, the taste of bread prepared with mixing of 10% Job's tears flour was better than flour bread and the volume and grains of the bread made from mixing of 10%, 20% Job's tears flour were similar to that of flour bread, but the taste, volume and grains of bread made from 30% mixed flour were undesirable. The rice cake Prepared from mixed flour with 25% Job's tears flour has shown to be desirable.

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Extrusion Process of Barley Flour for Snack Processing (스낵제조를 위한 보리의 압출성형공정)

  • Mok, Chul-Kyoon;Pyler, R.E.;Mcdonald, C.E.;Nam, Young-Jung;Min, Byong-Yong
    • Korean Journal of Food Science and Technology
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    • v.16 no.4
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    • pp.429-436
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    • 1984
  • To expand the utility of barley the experiments on the extrusion characteristics of barley flour for snack processing were carried out and the effects of the extrusion conditions on the quality of the extrudates were investigated. The optimum moisture content of barley flour for snack processing was 20%. The moisture content and the density of the extrudates decreased with increasing extrusion temperature and decreasing die size. The die swell ranged from 0.98 to 2.18 according to various extrusion conditions and decreased with increasing temperature above $150^{\circ}C$. The lightness, redness and yellowness increased at higher temperature. The water absorption index and the water solubility index showed their maximum values at $180^{\circ}C$.The gelatinization degree of the extrudates increased with increasing temperature. The fracture fore, Young's modulus and maximum fiber stress decreased, but the deformation to fracture increased, with increasing temperature and decreasing die size. The yield force in puncture test showed lower values at higher temperature. The size and the fraction of the air cells increased with increasing temperature and decreasing die size. The optimum extrusion conditions of barley for snack processing were at the temperature of $180^{\circ}C$, with the die size of 4.5mm when processed at 160 rpm.

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Product Characteristics as Factors of Process Parameters in Starch Phosphates Preparation by Twin-screw Extruder (이축압출성형기로 인산전분 제조시 Process Parameters에 따른 제품의 특성)

  • Kim, Chong-Tai;Kim, Dong-Chul;Kim, Chul-Jin;Kim, Hae-Sung
    • Korean Journal of Food Science and Technology
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    • v.23 no.2
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    • pp.235-240
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    • 1991
  • Starch phosphates were prepared from the corn starch mixed with 2% sodium tripolyphosphate by twin-screw extruder with a feed rate of 20 kg/hr and an extrusion temperature of $130^{\circ}C$, and the effects of extrusion variables on the physicochemical properties (target parameters) of starch phosphates were investigated. Interrelations of system parameters (specific mechanical energy and extrudate moisture) and rheological properities of starch was analyzed by using the response surface analysis. Degree of substitution (DS) was increased with increasing the feed moisture, and showed the maximum value at the screw of near 250 rpm, Degree of gelatinization was proportionally increased with increasing the screw speed and decreasing the feed moisture. Apparent viscosity of the paste was increased with increasing the feed moisture, but it was not significantly affected by the screw speed. It was found by scanning electron microscopy that the starch microgranules were much more degradaded, and as consequent result, the intrinsic viscosity was decreased, whereas, water solubility index was increased. The rate of retrogradation of the gels was retarded with increasing DS and decreasing viscosity.

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Quality Characteristics of Gugija.Heukimja Jook Containing Different Levels of Black Sesame Powder (흑임자 첨가량을 달리한 구기자흑임자죽의 품질특성)

  • Min, Eun-Seol;Cho, Jung-Soon
    • Korean journal of food and cookery science
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    • v.25 no.1
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    • pp.106-118
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    • 2009
  • This study was to investigated optimum preparation conditions for Gugija Heukimja jook by response surface methodology (RSM). The important materials used for the Gugija Heukimja product were Lycium chinese, Seasamum indicum L., Ziziphus jujuba Mill. and rice. Moisture content, crude protein, crude fat, crude ash and crude fiber content were 15.62, 16.60, 13.62, 4.93 and 11.17% for Lycium chinese, 3.62, 20.94, 43.56, 5.67 and 10.72% for Seasamum indicum L., 24.12, 5.38, 0.73, 2.30 and 1.25% for Ziziphus jujuba Mill., and 12.36, 6.98, 0.46, 0.43 and 0.41% for rice, respectively. Optimal extraction conditions of brix, color, pH and total acidity in the materials for Gugija Heukimja jook were temperature $80^{\circ}C$, water volume 850 mL and extraction time of 63 min. The spreadability of jook with Lycium chinese and Ziziphus jujuba Mill. extracts was the highest when black sesame was 12 g pH was the lowest when black sesame was 9 g. PH showed a significant difference when the added black sesame ratio changed. The 'value L' of chromaticity was lower with an increase of the black sesame ratio, 'value a' was higher with an increase of the black sesame ratio, 'value b' was lower with an increase of the black sesame ratio. Brix was lower when black sesame in jook was added. Total acidity was highest (7.27%) when black sesame was 12 g. The degree of gelatinization tended to be lower with additional black sesame. Higher scores of sensory evaluation were found for the product containing 9 g black sesame with Lycii furctus and Ziziphus jujuba Mill. extracts ompared to the other samples with 3 and 6g. No significant difference in taste occurred for Gugija Heukimja jook prepared with over 9 g black sesame, while a great difference showed in color, pH and total acid. Therefore, the Gugija Heukimja jook prepared under the optimal conditions of 9 g black sesame with Lycium chinese and Ziziphus jujuba Mill. extracts exhibited higher qualities. Gugija Heukimja jook can use the easier for Yacksun jook. It is expected to become functional in the product's development.

Growth Property and Seed Quality of Mungbean Cultivars Appropriate for Labor Saving Cultivation (생력재배에 적합한 녹두 품종의 특성)

  • Kim, Dong-Kwan;Son, Dong-Mo;Choi, Jin-Kyung;Chon, Sang-Uk;Lee, Kyung-Dong;Rim, Yo-Sup
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.3
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    • pp.239-244
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    • 2010
  • The purpose of this study was to identify mungbean (Vigna radiata L.) cultivars with appropriate characteristics for labor saving culture (whole crop feeding and combine harvesting), and to investigate seed quality in the southern South Korea. Cultivar Dahyeon exhibited strong lodging resistance, excellent disease tolerance, and greater pod numbers per plant resulting in higher yield. Cultivar Owool and Keumseong, the two most common mungbean cultivars in Korea, exhibited lower yield than Dahyeon due to weaker disease tolerance or lower pod numbers per plant. Cultivar Samgang demonstrated higher seed starch content, Jangan, Nampyeong, and Keumseong exhibited higher crude protein content, and Sohyeon exhibited higher vitexin and isovitexin contents. However, no statistical differences were found among the cultivars in crude fat content. Unsaturated fatty acid ranged from 51.8 to 57.2%, with saturated fatty acid ranging from 36.2 to 40.3%. We detected five unsaturated fatty acids including linoleic acid (36.1 to 38.6%), linolenic acid (10.3 to 14.7%), and oleic acid (2.7 to 4.6%), and seven saturated fatty acids including palmitic acid (28.7 to 30.9%), stearic acid (2.9 to 4.1%), and arachidic acid (1.5 to 3.7%). There were significant differences between the cultivars in amylogram properties of seeds: the Nampyeong cultivar exhibited a lower gelatinization temperature; Dahyeon was higher in peak viscosity and breakdown; and Sohyeon, Nampyeong, and Dahyeon were lower in setback.

Physicochemical Properties of Taro Flours with Different Drying, Roasting and Steaming Conditions (토란분말의 건조, 볶음 및 증자 조건에 따른 이화학적 특성)

  • Moon, Ji-Hye;Choi, Hee-Don;Choi, In-Wook;Kim, Yoon-Sook
    • Korean Journal of Food Science and Technology
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    • v.43 no.6
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    • pp.696-701
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    • 2011
  • To evaluate the processing adaptability of taro flours, the physicochemical properties of taro flour with different drying, roasting and steaming conditions were investigated. The moisture content and total dietary fiber were decreased as temperature increased with hot-air drying. Freeze-dried taro flours showed the highest vitamin C contents. Taro flours made by freeze-drying and hot-air drying showed significantly higher total dietary fiber content than those with roasting and steaming process. Steamed taro flours had the highest water absorption index, while hot-air dried and freeze dried taro flours had the highest water solubility index. No differences were displayed in the differential scanning calorimetry (DSC) thermal characteristics among hot-air dried and freeze dried taro flours. Roasted taro displayed decreased onset temperature and peak temperature as roasting temperature increased. Using a rapid visco-analyzer, the peak viscosity, through viscosity, and final viscosity of dried and steamed taro flours were higher than roasted taro flours, whereas the set back value, which is a prediction of retrogradation, decreased with steaming processing. From those results, it could be concluded that hotair dried taro flours, which have high gelatinization viscosity, are beneficial in imparting viscosity to dough products and hot-air drying after steaming taro flours, which retard retrogradation, is good for porridge and flake base products.

Effect of Gums on the Characteristics of the Dough in Making Frozen Dough (냉동생지 제조시 검류의 첨가가 반죽특성에 미치는 영향)

  • Lee, Jong-Min;Lee, Myung-Ku;Lee, Si-Kyung;Cho, Nam-Ji;Cha, Wook-Jin;Park, Jung-Kil
    • Korean Journal of Food Science and Technology
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    • v.32 no.3
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    • pp.604-609
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    • 2000
  • This study was carried out to investigate the possibilities of adopting xanthangum, guargum and ${\kappa}-carrageenan$ as cryprotectant by examining the rheological and structural properties of dough. Results of farinography showed that water absorption, development time and mechanical tolerance index in dough with the gums increased more than those of the control. It was also found that resistance in dough with the gums increased greatly, but extensibilities were similar to that of the control, resulting in increasing R/E values in the dough with the gums through extensograph. According to amylogram, gelatinization temperature of dough was $59.5^{circ}C$ and those of the dough with the gums were $58^{circ}C$. Even though maximum viscosity of the dough was 550 B.U in the control, those were 690 B.U, 780 B.U and 760 B.U in the dough with xanthangum, guargum, and ${\kappa}-carrageenan$, respectively. The control deeply increased the pH during frozen storage but the addition of ${\kappa}-carrageenan$ and xanthangum increased the pH slightly. The dough with the gums had more stable spaces than control in the microstructure through SEM.

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Quality Properties of Cooked Germinated-brown Rice (유통중인 발아현미밥의 품질특성)

  • Park, Jong-Dae;Cho, Bong-Kyu;Kum, Jun-Seok;Lee, Hyun-Yu
    • Food Science and Preservation
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    • v.12 no.2
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    • pp.101-106
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    • 2005
  • This study was carried rut to investigate the quality properties of two cocked germinated-brown rices(A- and B-product). Color value of A- and B-product were L=68.46, a=0.92, b=9.49 and L=69.32, a=-1.10, b=9.77, respectively. Moisture content of those was $64.5\%$. The free sugar contents of A-product were $0.2\%$ glucose, $0.15\%$ sucrose, $0.18\%$ maltose, and those of B-product were $0.14\%$ glurose, $0.50\%$ sucrose, $0.17\%$ maltose, respectively. Vitamin E content in A-product was $30.7\;{\mu}g\;100\;g$ and $46.9\;{\mu}g\;100\;g$ in B-product. Total dietary fiber contents were $2.8\%$, and $2.2\%$, respectively. The DSC(differential scanning calorimetry) characteristics of two cooked germinated-brown rices showed similar pattern. Onset temperature and gelatinization enthalpy of peak 1 were $56.5^{\circ}C$, 5.46 J/g in A-product and $56.2^{\circ}C$, 5.56 J/g in B-product, respectively. Onset temperature and melting enthalpy of peak 2 were $109.5^{\circ}C$, 0.33 J/g in A-product and $108.9^{\circ}C$, 0.37 J/g in B-product, respective1y. Sensory properties of cocked germinated-brown rices were affected by appearance, taste and texture. Palatability score of B-product was higher than that of A-product.

Effects of Milk Protein-Gum Conjugates on The Characteristics of The Dough and Staling of Bread Made of Frozen Dough During Freeze-Thaw Cycles (우유단백질-검류 복합체 첨가가 제빵용 반죽의 물리적 특성과 식빵의 노화에 미치는 영향)

  • Yun Young;Kim Young-Ho;Kim Young-Su;Choi Sung-Hee;Eun Jong-Bang
    • Food Science and Preservation
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    • v.13 no.1
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    • pp.30-36
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    • 2006
  • Milk protein-gum conjugates were prepared by Maillard reaction and added to dough to investigate the possibile use of them as anti-staling agents in bread Four different types of conjugates were added to dough, i.e., $casein-\kappa-carrageenan$ (CK), casein-sodium alginate (CA), $whey-\kappa-carrgeenan$(WK) and whey-sodium alginate (WA). Their addition to flour increased the gelatinization temperature, water absorption and development time of the dough. Extensogram showed the increased resistance to extension of the doughs resulting from the addition of the conjugates. Moisture content of the breads decreased during storage at $5^{\circ}C$ for 4 days. The breads added with conjugates had lower extents of the decreases than non-treated degrees and maintained higher moisture content than non-treated bread after 3 freeze-thaw cycles. The storage degrees at $5^{\circ}C$ for 4 days affected the increased bread hardness, but, addition of WA conjugate decreased extents of the increases. Therefore, milk protein-gum conjugates, especially WA conjugate, contributed to retarding staling of breads

Effect of Enteromorpha intenstinalis Powder Addition in the Quality of Dumpling Shell (만두피 제조시 파래 분말 첨가가 품질에 미치는 영향)

  • Park, Bock-Hee;Ju, Sung-Mee;Cho, Hee-Sook
    • Food Science and Preservation
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    • v.17 no.6
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    • pp.814-819
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    • 2010
  • We investigated quality changes in dumpling shells prepared using various concentrations of Enteromorpha intestinalis powder(EIP). Dumpling shells were prepared by addition of 0%, 3%, 5%, 7%, and 9%(all w/w) EIP to the flour used in the basic formulation. The gelatinization temperature of the EIP-wheat flour composite increased whereas initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 min, and maximum viscosity, all fell with increasing EIP content, as measured by amylography. In addition, the Hunter's color L, a, and b values decreased significantly with increasing amounts of EIP. All of cooked weight, cooked volume, and water absorption of dumpling shells prepared with EIP were significantly greater than control values. In terms of textural characteristics, addition of EIP increased hardness, springiness, and chewiness, but decreased adhesiveness and cohesiveness. Sensory evaluation showed that dumpling shells prepared with 5% (w/w) EIP were preferred.