• Food Science and Biotechnology
• /
• v.14 no.1
• /
• pp.32-38
• /
• 2005

Effects of acid and ${\alpha}$-amylase on resistant starches including retrograded RS3 and cross-linked RS4 prepared from normal maize starch were investigated. Acid and ${\alpha}$-amylase hydrolytic patterns of RS3 were similar, while those of native starch and RS4 differed. Acid hydrolysis rate of RS3 was markedly higher at initial stage, then slowly decreased up to 20 days, whereas that of RS4 increased continuously. The sizes of acid- and ${\alpha}$-amylase-treated RS3 residues decreased, but those of RS4 remained unchanged. X-ray patterns of all treated residues did not change; however, the peak intensities increased. Swelling power of RS3 increased to 150% at $95^{\circ}C$, whereas that of RS4 differed depending on the treatment condition. Swelling power of acid-treated RS4 residue increased markedly, but that of ${\alpha}$-amylase-treated one remained constant. Gel filtration chromatography profiles of untreated RS3 and RS4 residues were similar, whereas that of acid-treated RS4 residue was different from them. RS showed different hydrolytic behavior by acid and ${\alpha}$-amylase depending on the type, and susceptibility of RS3 was higher than that of RS4.

• Korean journal of food and cookery science
• /
• v.31 no.3
• /
• pp.248-254
• /
• 2015

We conducted this study to investigate the amount of RS and cooking characteristics of the commercial extrusion-cooked noodles. Ten kinds of noodles were selected and grouped according to the storage conditions; dry noodles (3), refrigerated noodles (2), freeze noodles (4), and dry noodle made from wheat flour as a control (not extrusion-cooked). The total starch of commercial noodles ranged from 62.50% to 84.13%, Refrigerated Naengmyeon and dry Dangmyun had high proportions of total starch (respectively 84.13% and 80.13%, respectively). The amounts of apparent amylose ranged from 25.01% to 42.93% and RS ranged from 0.61% to 5.99%. A high proportion of the total starch was rendered digestible by extrusion cooking, and a small amount of RS remained in the samples. Dry Dangmyun had the highest percentages of RS (5.99%), followed by refrigerated Naengmyeon C (2.41%) and dry Jjolmyeon (1.94%), and those of the other noodles were lower than that of the control (1.86%). Cooking properties and texture measurements were evaluated. Cooking loss and turbidity of cooking water were highest in dry Jjolmyeon and dry Naengmyeon. There was little cooking loss in dry Dangmyun and freeze rice noodles. In particular, dry Dangmyun and refrigerated Naengmyeon C containing high amounts of RS and amylose had relatively high measurements of hardness and tensile strength.

• Korean Journal of Agricultural Science
• /
• v.45 no.4
• /
• pp.779-787
• /
• 2018

The objective of this study was to investigate the structural and physicochemical properties of starch by barely cultivars. Hwanggeumchal had a moisture content and ${\beta}$-glucan content of 12.02 and 6.23%, respectively. Hyegang had higher protein contents than those of the other cultivars. As a result of observing the particle size of starch, Hwanggeumchal and Hyegang had smaller particles of starch compared with the other cultivars at 15.7 and $15.9{\mu}m$, respectively. The analysis results on the content of damaged starch showed that Dahan and Hyegang had a damaged starch content of 1.14 and 1.20%, whereas Boseokchal and Hwanggeumchal were 0.76 and 0.49% respectively, showing low waxy cultivars. As for the content of amylose, the results show that Dahan and Hyegang had an amylose content of 37.07 and 37.75%, and Boseokchal and Hwanggeumchal were at 11.22 and 37.75%, respectively. As for the degree of amylopectin polymerization, all four cultivars had the highest degree of polymerization (DP) content of 13 - 24 at more than 54%, whereas the DP content ${\geq}37$ was the lowest at less than 5.35%. The results for the soluble and resistant starch content show that the content of soluble starch ranged from 93.90 to 95.76%, and resistant starch was 0.17 - 0.40%. After analyzing the gelatinization properties of barley starch, the value of the setback was low in Hwanggeumchal and Hyegang; thus, it is considered that the aging process of those cultivars will be slower than that of the others.

• Korean journal of food and cookery science
• /
• v.32 no.3
• /
• pp.253-260
• /
• 2016

Purpose: To develop fat-free dressing containing a resistant starch (RS) as a dietary fiber, the viscosity and stability of various type RSes prepared from wheat, maize, potato, rice, waxy rice, and amaranth starches were investigated by using Brookfield viscometer. The shape of RS granule in the dressing during storage was also observed. Methods: The viscosity of fat free dressing with different retrograded RS3 (RS3V) prepared from waxy rice starch with 0.1% lemon vinegar and ascorbate mixed solution had higher RS3 that was maintained constant during storage. Annealing and heating prior to cross-linking, and heating after cross-linking increased RS level of RS4 type starches. Results: The viscosities and stabilities of dressings with RS were different depending on starch sources and RS preparation conditions. The heated RS4 (HRS4) increased in viscosity and stability with RS4 addition. Especially the fat-free dressings with HRS4 prepared from rice and waxy rice starches maintained stability regardless of separation after one month storage with only 7% separation after 6 month storages. The shape of RS4 granule in acidic medium of dressing did not change until 6 months. Conclusion: In this study, RS4 made by the rice and waxy rice starches showed high viscosity and maintained stability of the fat-free dressings during storage.

• Journal of the Korean Society of Food Culture
• /
• v.26 no.5
• /
• pp.521-529
• /
• 2011

This study evaluated the effects of different levels of malt extract on the hardness, moisture, water soluble starch (WSS) contents, and in vitro starch digestibility (IVSD) of Jeungpyun during storage at room temperature ($25{\pm}1^{\circ}C$) and refrigeration temperature ($4{\pm}1^{\circ}C$). Resistant starch (RS) and soluble starch (non-RS) contents were also evaluated. During storage at both temperatures, hardness increased in Jeungpyuns with the malt extract-added Jeungpyun groups (malt-added Jeungpyuns) exhibiting lower hardness than the control. The rate of retrogradation was faster upon storage at refrigeration temperature. Moisture and WSS contents as well as IVSD of Jeungpyuns decreased, whereas these levels were higher in malt-added Jeungpyuns compared to control. Storage increased RS contents in Jeungpyuns stored for up to 4 days, particularly at $4^{\circ}C$, whereas there was a decrease in RS content after 7 days of storage. However, RS content was lower in malt-added Jeungpyuns compared to control. Soluble starch (SS) contents of Jeungpyuns decreased. However, SS content was higher in malt-added Jeungpyuns than that of control. The reduced hardness and RS content as well as the rate of increase in other parameters of malt-added Jeungpyuns were dependent on the concentration of malt extract. These results reveal that addition of malt extract delayed retrogradation of Jeungpyun, whereas retrogradation possibly increased the content of RS during storage at both temperatures, however, that of RS decreased with increasing level of malt extract, suggesting that the level of malt extract as well as the storage conditions are important for obtaining acceptable texture and retaining the RS content of Jeungpyun, which is known to possess physiological activity.

• Korean Journal of Human Ecology
• /
• v.2 no.2
• /
• pp.29-38
• /
• 1999

저항전분(RS)은 건강한 사람의 소장에서 소화되지 않는 전분이나 전분질 식품의 부분이다. 저항전분은 4가지 형태로 구분하는데 RS 1은 물리적으로 효소와 만나지 않는 부분, RS 2는 생전분으로 감자, 바나나와 고아밀로오스 옥수수전분, RS 3는 노화된 전분 그리고 RS 4는 화학적으로 변성시킨 전분이다. RS 함량은 열에 안정한 $\alpha$ -아밀라아제나 pancreatin, pancreatic $\alpha$ -아밀라아제와 미생물에서 분리된 아밀라아제 등을 이용한 몇 가지 방법에 의해 분석되고 있다. RS는 대장에서 미생물에 의해 발효되어 단쇄지방산을 생성하는데 특히 부티릭산이 생성된다. 아세트산이나 프로피온산은 간의 대사에 영향을 주며 부티릭산은 항 종양(항 대장암) 특성이 있다. RS는 소화가 되지 않아 저열량원이므로 당뇨병 환자나 운동에 의한 혈당 조절이 필요할 때 조절능력을 갖는다. RS가 건강에 중요한 인자임이 알려지면, 건강을 위해 매일 섭취량의 증가를 권장해야 할 것이다.

• Journal of the Korean Society of Food Culture
• /
• v.22 no.4
• /
• pp.468-474
• /
• 2007

Physicochemical and sensory characteristics of cookies with various levels of resistant starch were investigated in this study. Dough pH of 30% substituted sample group had significantly the highest value than that of all(p<0.05). Water contents of Dough were decreased with increased levels of the resistant starch in cookie preparation. The spreadability was increased as the addition levels of the resistant starch were increased. The Hunter L and a values of 30% substituted sample group had the highest values of all(p<0.05). Results of sensory characteristics of 30% substituted sample group showed significantly the lower values in hardness and crack than those in the other groups at p<0.05. Acceptance tests of cookies with 10 and 20% substituted sample groups showed higher values in savory flavor and overall acceptability than those of others.

• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.516-521
• /
• 1997

Effect of amylose content on the physical properties of resistant starches (RS) from autoclaved maize starches (with starch:water=1:3.5, at $121^{\circ}C$) which were repeated up to 4 times heating-cooling cycles, were investigated by water uptake, scanning electron microscope (SEM) and differential scanning calorimetry (DSC). Amylose content of waxy maize starch (Amioca), common maize starch (PFP), high amylose starch(Amaizo, Amylomaize VII) were 0%, 29%, 50%, and 72%, respectively. Yield of RS increased as amylose content increased. Water uptake of all kinds of native starch was higher than that of RS, but lower than that of autoclaved starch. By SEM, RS showed some small particles on surface but the size of particles was different with amylose content. Single endothermic transition peak exhibited at $40{\sim}70^{\circ}C$ in autoclaved Amioca and PFP (crystalline melting of amylopectin) and at $132{\sim}169^{\circ}C$ in autoclaved Amaizo and Amylomaize VII(crystalline melting of amylose) by DSC. RS from all kinds of autoclaved starches except Amioca showed single endothermic peak over $155^{\circ}C$ but the enthalpy was not related to amylose content.

• Korean Journal of Food Science and Technology
• /
• v.49 no.1
• /
• pp.1-7
• /
• 2017

Molecular structure, physicochemical properties, and in vitro digestibility of starch from Korean rice cultivars for special uses (Baegjinju 1, Hanareum, Deuraechan, and Goami 4) were investigated. The starch from Baegjinju 1 had the lowest amylose content (9.7%) and Hanareum, Deuraechan, and Goami 4 had intermediate amylose (20-25%) contents. Baegjinju 1 had a lower proportion of short amylopectin branch chains than the other rice starches. Hanareum had the lowest relative crystallinity and the highest intensity ratio of $1047cm^{-1}/1022cm^{-1}$ among the rice starches. The starch from Goami 4 had a higher pasting temperature and lower gelatinization enthalpy than the other rice starches. Peak viscosity of rice starch from Baegjinju 1 was substantially higher than peak viscosity of other rice starches. Rice starch from Baegjinju 1 had significantly higher rapidly digestible starch content and lower resistant starch content than other rice starches, whereas there was no significant difference in resistant starch content among the rice starches.

• Korean Journal of Food Science and Technology
• /
• v.30 no.5
• /
• pp.1128-1133
• /
• 1998

Extrusion cooking treatment was compared with autoclaving/cooling treatment for formation of enzyme resistant starch of high amylose corn starch (HACS). Effects of barrel temperature $(100^{\circ}C,\;120^{\circ}C,\;140^{\circ}C)$ and feed moisture content (25%, 35%, 45%) on extrusion processing in a co-rotating twin-screw extruder under fixed screw speed (100 rpm) were investigated by measuring enzyme resistant starch (RS) yield. RS yield were estimated by in-vitro pancreatin digestion method and enzymatic-gravimetric method using termamyl. Barrel temperature and yield of RS were negatively correlated and feed moisture content and yield of RS was positively correlated as determined by in-vitro pancreatin method. The highest yield (38.4%) of RS was obtained from HACS extrudate processed at the barrel temperature of $100^{\circ}C$ and the feed moisture content of 45%, while the yield of RS by 5 times of autoclaving/cooling was 25%. The yield of RS by in vitro pancreatin digestion method was 20.7% with high amylose corn starch and 8.2% with ordinary corn starch (CS), respectively, under the same extrusion condition (barrel temperature $120^{\circ}C$, feed moisture content 35%). At the same condition, the yields of RS by enzyme-gravimetric method were 14.6% with HACS and 6.8% with CS, respectively. The yield of RS increased during the storage at $4^{\circ}C$ for 4 weeks and the highest yield (60%) was obtained by the storage of HACS extrudates extruded at $100^{\circ}C$ and 45% feed moisture content.