• Title, Summary, Keyword: high amylose starch

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Molecular Characteristics and Functional Properties of Barley Starches with Varying Amylose Content

  • You, Sang-Guan;Kim, Sang-Moo
    • Preventive Nutrition and Food Science
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    • v.10 no.3
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    • pp.207-213
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    • 2005
  • Molecular structures and functional properties of starches isolated from normal, waxy, and zero amylose barleys were examined. Amylopectins from zero amylose starch had the largest molecular weight $(M_w)$, whereas those from high amylose starch, the smallest. A good correlation between the $(M_w)$ and the radius of gyration $(R_g)$ was observed among amylopectins from various starches, indicating similar polymeric conformation in solution even with the differences in the $(M_w)$. The debranched amylopectin molecules from different types of barley starches exhibited similar profiles, implying that the packing geometry of double helices in the different types of barley starches may be similar. Zero amylose starch showed the highest peak viscosity (326 RVU) in RV A viscograms at lower pasting temperature $(67.6^{\circ}C)$, compared to normal and high amylose starches. Relationship between RVA peak viscosity and amylose content suggested that the presence of amylose inhibited the development of granular swelling of barley starches during cooking. A rapid retrogradation, traced by differential scanning calorimetry (DSC) and strain-controlled rheometry, occurred in the high amylose starch sample during storage, while zero amylose starch showed a very good resistance to retrogradation, indicating excellent storage stability.

Effects of Amylose Contents and Degree of Gelatinization of Rice Flour on In Vitro Starch Digestibility, Physical Characteristics, and Morphological Properties

  • Park, Ji Eun;Bae, In Young;Oh, Im Kyung;Lee, Hyeon Gyu
    • Food Engineering Progress
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    • v.21 no.4
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    • pp.341-350
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    • 2017
  • The relationship of in vitro starch digestibility and gel strength was investigated at various concentrations (10-30%) of rice cultivars with different amylose contents (27.9, 17.9, and 5.2%). As the rice flour concentration increased, predicted glycemic index decreased, but gel strength increased regardless of amylose contents. Gel strength correlated strongly with amylose content, whereas in vitro starch digestibility was more highly affected by rice flour concentration than by amylose contents. Moreover, the impact of degree of gelatinization on in vitro starch digestibility of high amylose rice was also examined in terms of structural features and rheological properties. The digestion rate of fully gelatinized flour was 1.7 times higher than that of native flour, while the disrupted structure with a different gelatinization degree during starch digestion was visually demonstrated through the X-ray diffraction and molecular distribution analysis. The rice flour changed from an A-type to a V-type pattern and showed difference in crystalline melting. The low molecular weight distribution increased with increasing degree of gelatinization during starch digestion. The apparent viscosity also increased with degree of gelatinization. These results demonstrated that the starch digestibility of rice was more affected by concentration than by amylose content, as well as by the degree of gelatinization due to structural difference.

Effect of high amylose corn starch/dextrin on quality of non-fried instant noodles (고아밀로스 옥수수전분/덱스트린의 첨가가 건면의 품질에 미치는 영향)

  • You, Jae Geun;Lee, Ju Hun;Park, Eun Young
    • Korean Journal of Food Science and Technology
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    • v.52 no.6
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    • pp.655-660
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    • 2020
  • High amylose corn starch and dextrin (acid-treated at 30, 40 and 50℃ denominated as Dextrin30, Dextrin40 and Dextrin50) were added to non-fried instant noodles. X-ray diffraction pattern, water absorption, cooking loss, microstructure, and textural properties of non-fried instant noodles were investigated. The addition of high amylose corn starch/dextrin induced a slight peak intensity at 20o in the X-ray pattern indicating the insignificant formation of amylose-lipid complex. Non-fried instant noodles including high amylose corn starch/dextrin showed lower water absorption than the control. Dense microstructure in transverse section of noodles was observed in non-fried instant noodles including high amylose corn starch/dextrin except Dextrin50. Also, the addition of high amylose corn starch/dextrin induced low tensile strength, high firmness, and high stickiness. However, non-fried instant noodles containing Dextrin50 showed a loose microstructure and high cooking loss (3.98%), which might be associated with the textural properties such as the lowest tensile strength (0.17 N), lowest increase in firmness (46.77 N) and highest stickiness (18.43 N).

Crystalline Structure of the Extrudate of High Amylose Corn Starch (압출성형 고아밀로즈 옥수수전분의 결정 구조)

  • Kim, Ji-Yong;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.30 no.5
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    • pp.1024-1028
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    • 1998
  • Crystalline structure of the extrudate of high amylose corn starch was studied by X-ray diffractometer and $^{13}C\;NMR$. The X-ray diffraction crystal ratio of the extrudates (barrel temperature $100^{\circ}C$ )of high amylose corn starch slightly increased from 6.08% to 8.37% by increasing feed moisture content from 25% to 45%. But extrudates of high amylose corn starch showed similar crystal ratio on various extrusion conditions. Extrudates of high amylose corn starch (feed moisture content 20%, barrel temp $140^{\circ}C$) showed more enlarged crystal structure than that of non-extrudates. The perpendicular distance of crystal increased by extrusion. Crystal ratio was changed from $6.3{\sim}8.3%$ to $4.5{\sim}5.8%$ during storage at $4^{\circ}C$. Starch configuration was examined with $^{13}C\;NMR$. Double helical content was measured by $^{13}C\;NMR$ method. The highest double helical content (60%) was obtained from high amylose corn starch extrudate (barrel temp.: $100^{\circ}C$, feed moisture content 45%). Double helical contents and resistant starch (RS) yield (pancreatin) were positively correlated. However, double helical content of the extrudates was not changed by the storage at $4^{\circ}C$.

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Hydrolysis of Various Substrates by Two Forms of the Purified Glucoamylase from Rhizopus oryzae (Rhizopus oryzae로 부터 정제(精製)한 두가지형의 Glucoamylase의 각종기질(各種基質)의 가수분해(加水分解))

  • Hou, Won-Nyong;Chung, Man-Jae
    • Korean Journal of Food Science and Technology
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    • v.16 no.4
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    • pp.398-402
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    • 1984
  • These experiments were conducted to investigate the substrate specificity, the hydrolysis products on the various carbohydrates and the hydrolysis rate on the various raw starches of the two purified glucoamylase produced by Rhizopus oryzae. Both of the glucoamylases hydrolyzed amylose, amylopectin, glycogen, soluble starch, pullulan, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose and maltooctaose, but did not act on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, raffinose, sucrose and lactose. When the reaction mixture of glucoamylase and polysaccharides were incubated $37^{\circ}C$for 32 hours, glucoamylase I hydrolyzed amylopectin, soluble starch and amyloses completely, but hydrolyzing glycogen up to only about 88%. Glucoamylase II hydrolyzed the previous four polysaccharides up to about 100%. Both of the glucoamylases produced only glucose for various substrates and did not have any ${\alpha}-glucosyl$ transferase activity. Both of the glucoamylases hydrolyzed raw glutinous rice starch almost complety, wheras they acted on raw potato starch, raw green banana starch, raw arrow root starch, raw corn starch, raw yam starch and raw high amylose corn starch weakly. Glucoamylase II hydrolyzed raw starches at the higher rate than glucoamylase I.

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Physicochemical Properties of Rice Starch by Amylose Content (아밀로오스 함량별 쌀전분의 이화학적 특성)

  • Lee, Sang-Hyo;Han, Ouk;Lee, Hyun-Yu;Kim, Sung-Soo;Chung, Dong-Hyo
    • Korean Journal of Food Science and Technology
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    • v.21 no.6
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    • pp.766-771
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    • 1989
  • physicochemical properties of rice starch isolated from eight varieties were examined to evaluate the rice processing suitability The amylose contents of rice starch were varied with 16.7-29.7%, and IR 30, Godael, Aguja and Lengkwang varieties showed higher amylose content than the other varieties. The water binding capacity and blue value were in the range of 87.0 103.0 and 0.178-0.305, respectively. As the amylose content increased, the amylogram pasting temperature and the break down ratio increased, while the peak viscosity did not show any significant difference. The transmittance of 0.1% starch suspension slowly increased at $50^{\circ}C$ in the low-amylose content rice group, and rapidly increased at $65^{\circ}C$ in the high-amylose content rice group, but there were no differences above $75^{\circ}C$ among varieties. Also the low-amylose rice starch showed higher values in the swelling power and solubility. The hardness of the 30% rice starch gels was low in low-amylose one. During storage at $20^{\circ}C$ for 14 days, the increment of hardness was more slow in high-amylose one. The retrogradation velocity constant of rice starch gel by Avrami equation was the highest as 0.219 in Aguja variety.

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Enzyme-Resistant Starch Content, Physical and Sensory Properties of Tarakjuk (Milk-Rice Porridge) with Different Amylose Content (아밀로즈 함량별 타락죽의 효소저항전분 함량, 물리적 및 관능적 특성)

  • Lee, Gui-Chu;Kim, Jung-Eun;Kim, Yoon-Sun
    • Journal of the Korean Society of Food Culture
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    • v.21 no.2
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    • pp.171-178
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    • 2006
  • Tarakjuk with different amylose content was made up using roasted rice flours that consisted of the highest enzyme-resistant starch (RS), while differential scanning calorimetry (DSC) was also utilized to measure the gelatinization temperature of these roasted rice flours in order to establish cooking temperature of tarakjuk. The following qualities of tarakjuk with different amylose content were studied: color, viscosity, spreadability, starch fractions involving total starch (TS), rapidly digestible starch (RDS), slowly digestible starch (SDS) and RS, in vitro starch digestibility (IVSD) and sensory properties. During experimentation, it was found that as the amylose content of the rice flour decreased, the L value of tarakjuk decreased, whereas a value increased significantly (p<0.05). Also, while viscosity showed to increase significantly (p<0.05), on the opposite end, the property of spreadability decreased. TS ranged from $15.95{\sim}17.31%$, RDS $9.36{\sim}10.16%$, SDS $5.46{\sim}6.91%$ and RS $0.33{\sim}1.07%$, on a dry basis. Although the amylose content of rice flours decreased, IVSD increased, however showing no significant difference. When testing the sensory properties of tarakjuk, color and viscosity increased, whereas clumpiness decreased. Ilpum tarakjuk showed the highest score for nutty taste and overall acceptance levels. In fact a high correlation was shown between nutty taste and overall acceptance level (p<0.01), which leads one to believe that nutty taste is a prime factor that greatly influences overall acceptance. Furthermore, viscosity was positively correlated with both a and b values, however negatively correlated with L value (p<0.05). Moreover, roasted nutty taste and overall acceptance were positively correlated with a value (p<0.05), respectively. In conclusion, the above results suggest that tarakjuk could be made by choosing the appropriate rice flour based on the nutritional or sensory purpose.

Effects of High Amylose Starch on Gut Functions in Rats (고아밀로오스전분의 섭취가 흰쥐의 장기능에 미치는 영향)

  • 설소미;방명희;정미경;김우경
    • Journal of Nutrition and Health
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    • v.36 no.2
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    • pp.109-116
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    • 2003
  • This study investigated the effects of high amylose starch (HAS) consumption on gut functions in male Sprague-Dawley rats. Experimental animals were fed an diet containing HAS for 4 weeks (0, 125, 250, 500 g/kg diet). Stool weights, transit time, the pH of cecum, Bifidobacterium growth, short chain fatty acid production, and prostaglandin E$_2$production in colon mucus were measured. HAS intake did not affect body weight gain or food efficiency ratio during experimental period. There were no significant differences in kidney weight, epididymal fat pad weights or spleen weights, but the weights of the liver and thymus were significantly lower in the HAS100 group. The length of the large intestine, the weights of the cecum wall and cecum contents, and stool weights significantly increased through HAS intake. But transit time was not affected by the experimental diet. Although Bifidobacterium growth in the cecum increased through the HAS intake dose dependently, there were significant differences in the HAS50 and HAS100 groups. HAS intake increased the production of short chain fatty acid in the cecum contents. In particular, acetate and butyrate concentrations grew significantly. And the production of prostaglandin E$_2$in the colon mucus significantly decreased through HAS intake. These results demonstrate that high amylose starch intake significantly improves gut function.

Studies on the Exo-maltotetraohydrolase of Pseudomonas stutzeri IAM 12097 -Part III. Reaction products and hydrolysis rate on various carbohydrates of Exo-maltotetraohydrolase- (Pseudomonas stutzeri IAM 12097 의 Exo-maltotetraohydrolase에 관한 연구(硏究) -제3보(第三報). 각종기질(各種基質)에 대(對)한 Exo-maltotetraohydrolase의 분해산물(分解産物) 및 분해율(分解率)-)

  • Lee, Mi-Ja;Chung, Man-Jae
    • Applied Biological Chemistry
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    • v.28 no.1
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    • pp.1-7
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    • 1985
  • Exo-maltotetraohydrolase produced by Pseudomonas stutzeri IAM 12097 was characterized with respect to substrate specificity, the reaction products and hydolysis rate on various carbohydrates. Maltopentaose, maltoheptaose, soluble starch, amylose, amylopectin, oyster glycogen and gelatinized starch of corn, potato, glutinous rice, green banana and arrow root were hydolyzed by this enzyme, but ${\alpha},{\beta},{\gamma}-cyclodextin$, sucrose, raffinose, lactose, pullulan, maltose, maltotriose and maltotetraose were not hydrolyzed. Among oligosaccharides, maltohexaose was favorably hydrolyzed by this enzyme and the main reaction product of oligosaccharides and polysaccharides was maltotetraose. Addition of pullulanase to this enzyme increased the hydolysis rate on gelatinized starches. tut it did not on raw starches. Among various starches, corn starch was favorably hydrolyzed by this enzyme, whereas it acted on potato starch, arrow root starch and high amylose corn starch weakly.

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