• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.303-308
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• 1998

Influence of amylose content on formation and characteristics of enzyme-resistant starch (RS) was investigated by scanning electron microscopy, X-ray diffractometry and differential scanning calorimetry. RS yield increased up to 36.1 % as the amylose content of corn starch increased. Starch granules of Amyulomaize V and Ⅶ were more rounded and smaller than those of regular corn ; some were elongated and had appendages. After autoclaving -cooling cycles, the granular structure disappeared and a continous spongy-like porous network was visible in regular corn starch ; the granular structure was stillevident in parts in Amylomaize V and Ⅶ starches. In all isolated RS residues , the porous structures were no longer visible and more compact formations predominated. While regular corn starch showed an A-type X-ray profile, Amylomaize V and Ⅶ starches exhibited a combination of B- and V-types. Regular corn starch lost most of its crystallinity during autoclaving , but the crystallinity was still left in Amylomaize starches as diffuse or poor B-types. All RS residues showed the presence of poor B-type regardless of amylose contents. Transition temperatures and enthalypy of native starches were a little higher in Amylomaize V and Ⅶ starches than those of regular corn starch . Regardless of amylose contents, all RS residues exhibited an endothermic transition over a similar temperature range (135 $^{\circ}C$~169$^{\circ}C$), with a mean peak temperature of ~154$^{\circ}C$, which is generally foud for retrograded amylose crystallities. Higher transition temperature, enthalypy, and RS yield of AMylomaize V and Ⅶ starches were related granular stability shown by the microscopic and crystallographic studies.

• Korean journal of applied entomology
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• v.21 no.3 s.52
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• pp.128-132
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• 1982

Starch contents in healthy and powdery mildew-infected spring barley leaves at first and fifth leaf stages were measured at different intervals after inoculation. Different patterns of starch accumulation in the susceptible cultivar Peruvian and the adult plant resistant cultivar Asse were found in infected first and fifth leaves. At the early phase of infection, the amount of starch in infected first leaves was slightly changed in both cultivars. During colony development and sporulation, the decrease in starch content was .more marked in the susceptible Peruvian, whereas the amounts of starch in the adult plant resistant Asse increased during colony development and then decreased sharply before and after sporulation. In heavily infected first leaves, the susceptible cultivar Peruvian showed a drastic decrease in starch content. In the adult plant resistant cultivar Asse, the higher amount of starch retained in these infected leaves, regardless of infection intensity. The regulation of starch accumulation in mildewed barley plants at different leaf stages was discussed in relation to adult plant resistance of spring barley.

• 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.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.532-538
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• 2006

Physicochemical and sensory characteristics of the jelly prepared with various levels of resistant starch were investigated in this study. Water content of RS10 sample group had significantly the highest value of 12.55% and that of the RS20 sample group had significantly the lowest value of all (p<0.05). RS20 sample group had significantly the highest value in sweetness. The value of pH were decreased with increased levels of the resistant starch in jelly preparation. The Hunter L values were not significantly different among the sample groups, but the RS20 sample group had the highest value of all. The hardness was increased as the addition levels of the resistant starch was increased. Results of sensory characteristics of RS20 sample group showed significantly the higher values in strawberry aroma, sweetness and after taste and significantly the lower value in stickiness than those in the other sample groups at p<0.05. Strawberry flavor, springiness and glossiness of RS5 sample group had significantly the largest values of all (p<0.05). The sensory properties of clarity and glossiness were negatively correlated with the mechanical properties of the color value and hardness at p<0.05. Sensory sweetness and after taste showed negative correlation with the values of pH in jelly preparation(p<0.05).

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.383-386
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• 1997

Maize starches with different amylose content were repeated autoclaving-cooling cycles up to 4 times, and the yield of resistant starch (RS) from autoclaved maize starches was investigated by enzymatic-gravimetric method and ${\alpha}-amylase$ treatment. With increasing amylose content in starch and the number of autoclaving-cooling cycles, RS yield was also increased, regardless of isolation method. Enzymatic-gravimetric method severely hydrolyzed amorphous region of autoclaved maize starches. Crystalline region was obtained more effectively by enzymatic-gravimetric method than by ${\alpha}-amylase$ treatment.

• Korean journal of food and cookery science
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• v.15 no.4
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• pp.418-425
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• 1999

The characteristics and yield of resistnat starch (RS) in waxy starches which were treated with 0.1N HCl were investigated. Hydrolysis rate of waxy starches were 0.32-0.88%. The yields of RS in waxy maize and waxy barley starches increased with acid treatment time up to 12hr and then decreased. The yield of RS in waxy rice starches increased with acid treatment up to 8hr and then decreased. The hydrolysis and yield of RS were different depending upon the varieties of starch source. Autoclaved normal maize starch showed a gel-like structure, but autoclaved normal maize starch showed crystal particle on the surface by SEM. The shape of autoclaved resistant starch was not different from acid treated ones. X-ray diffraction patterns of native and acid treated starches were all A-types. X-ray diffraction patterns of autoclaved waxy maize starches showed amorphous structures, however, those of RS showed all completely crystalline structure.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.301-303
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• 2005

Effort of rice resistant starch (RS) content on glucose blood level of normal Subject was examined using Suwon 464 and Ilpum, haying different RS contents. Enzymatic-gravimetric method showed RS contents of Suwon 464 and Ilpum were 16.3 and 0.7%, respectively. Both rice varieties, each containing 50g carbohydrate, were pressure-cooked and fed to ten healthy male volunteers after overnight fast. Significant difference was observed in 60 min blood glucose levels of Suwon 464 and Ilpum after meal, showing $90.3{\pm}4.8$ and $111.6{\pm}2.7mg/dl$, respectively (p<0.01).

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.133-138
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• 2002

To examine the cholesterol-towering effects of extruded products made with cassava starch (CS) and blends of cassava starch with either resistant starch (CS-RS) or oat fiber (CS-OF) hamsters were fed with diets containing a high-cholesterol (2%) and high-fat (17%) diet for 20 days. Hamsters fed with a diet containing no cholesterol were used as a control. Total cholesterol (TC) levels in the CS-RS and CS-OF groups were significantly (p>0.05) lower compared to the CS group by 11.5% and 8.5%, respectively. Also, the diets containing fibers decreased the value of low-density lipoproteins plus very low-density lipoproteins fraction by 32.4% (CS-RS diet) and 51.7% (CS-OF), respectively, as compared to the CS diet. Total lipid values were significantly (p<0.05) lower in hamsters fed the CS-RS diet (916 mg/dL) and CS-OF diet (964 mg/dL) as compared to those fed the CS diet (1661 mg/dL). The results obtained in this study suggest that extruded products containing cassava starch blended with either resistant starch or oat fleer, could prevent health problems associated with high levels of cholesterol and hypertriglyceridemia induced by a high cholesterol and fat diet.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.220-224
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• 1997

As corn starches with different amylose content were heated at different temperature $(100^{\circ}C,\;121^{\circ}C)$ with starch / water ratio (1:3.5, 1:9) and heating-cooling treatment was repeated up to 4 times, the yield of RS(resistant starch) from heated corn starches was investigated by the enzymatic-gravimetric method and the ${\alpha}-amylase$ treatment. Compared to ${\alpha}-amylase$ method, enzymatic-gravimetric method was more effective to hydrolyze the amorphous region of heated corn starch. With increasing the amylose content and the number of heating-cooling treatment, the yield of RS increased, regardless of isolation method. Heated corn starches formed at $121^{\circ}C$ provided higher yield of RS than those formed at $100^{\circ}C$. Higher RS yield was also observed in the case of starch/water ratio (1:3.5) compared to the case of ratio (1:9).

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1309-1315
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• 1997

Yields of enzyme-resistant starch (RS) from three kinds of maize starches (Amioca, normal starch and Amylomaize VII) which were treated with 1 N HCl for 24 hr and physicochemical characteristics were investigated. Hydrolysis rate of maize starches decreased with increasing amylose content. Maximum wavelength $({\lambda}_{max})$ and iodine affinity were decreased by the acid treatment. The yields of RS increased with acid treatment up to 12 hr and then decreased. The yield of for 12 hr acid-treated Amioca increased 8 times more than untreated sample, but those of normal starch and Amylomaize VII slightly increased. Using SEM, acid-treated and autoclaved maize starches showed gel like structure, but RS had round and rod shape small particles. X-ray diffraction patterns of autoclaved starches showed amorphous structure in Amioca and B-type in normal starch and Amylomaize VII, and those of RS showed all completely crystalline structure.