• Korean Journal of Food Science and Technology
• /
• 제27권6호
• /
• pp.839-844
• /
• 1995

Appropriate types and concentrations of starch-based fat replacers which are low-pH stable, shear resistant and heat stable were selected to develop reduced-fat mayonnaise without affecting taste, texture and emulsion stability. Four kinds of commercial fat replacers [Neutral DR (DR), Stellar 100X (SX), Sta Slim 150 (SS) and N-Lite L (NL)] were thermally activated after appropriately hydrated and applied to mayonnaise formulation. For each fat replacer, eight recipes having various ratios of soybean oil/fat replacer(95/5 to 60/40) were formulated and compared with standard formulation(100% soybean oil) using rheological and sensory evaluations. All tested starch pastes showed pseudoplastic behavior, time-dependent thixotropic gel characteristics. The increasing order of pseudoplasticity and yield stress was RM, NL, SS and ST. The hardness and adhesiveness of each fat replacer-added mayonnaise was increased in the same order as above. Formulated mayonnaise which contained higher ratio of fat replacer showed lower values in hardness and adhesiveness. ST at up to 25% oil replacement exhibited the highest oil replacing ability among four replacers. ST-added mayonnaise also exhibited the highest sensory score and emulsion stability among all products including standard formula. The high sensory score in spreadability of RM-added mayonnaise well reflected the consistent index of RM paste. Use of fat replacers reduced oily odor and greasy aftertaste of mayonnaise.

• Korean Journal of Food Science and Technology
• /
• 제37권3호
• /
• pp.438-442
• /
• 2005

Granule swelling is essential phenomenon of starch gelatinization in excess water, and characteristic of heated starch dispersion depends largely on size and distribution of swelled starch granule. Although swelling characteristic of starch granules depends on type of starch, heating rate, and moisture content, influence of heating rate on swelling phenomenon of starch granule has not been fully discussed, because constant heating rate of starch dispersion cannot be obtained by conventional heating method. Ohmic heating, electric-resistant heat generation method, applies alternative current to food materials, through which heating rate can be easily controlled precisely and conveniently at wide range of constant heating rates. Starch dispersion heated at low heating rates below $7.5^{\circ}C/min$ showed Newtonian fluid behavior, whereas showed pseudoplastic behavior at heating rates above $16.4^{\circ}C/min$. Apparent viscosity of starch dispersion increased linearly with increasing heating rate, and yield stress was dramatically increased at heating rates above $16.4^{\circ}C/min$. Average diameter of corn starch granules during ohmic heating was dramatically increased from $30.97\;to\;37.88\;{\mu}m$ by increasing heating rate from $0.6\;to\;16.4^{\circ}C/min$ (raw corn starch: $13.7\;{\mu}m$). Hardness of starch gel prepared with 15% corn starch dispersion after heating to $90^{\circ}C$ at different heating rates decreased gradually with increasing heating rate, then showed nearly constant value from $9.4\;to\;23.2^{\circ}C/min$. Hardness increased with increase of heating rate higher than $23.2^{\circ}C/min$.

• Korean journal of food and cookery science
• /
• 제21권6호통권90호
• /
• pp.823-828
• /
• 2005

To lower the calories of buckwheat noodle, which is good for reducing obesity and for Preventing adult disease, glucomannan and flour containing resistant starch(RS) were used during the noodle making Process. Compared with raw noodle, this buckwheat raw noodle had $30\%$ fewer calories. This low caloric buckwheat noodle was coated with olive oil which is reputed as well-being food to prevent soddening to make instant type buckwheat noodle. Its shelf-life was extended to 90 days under normal temperature($35^{\circ}C$I). Among four noodle samples with different combinations of raw materials, the best was made of flour with RS formula flour, buckwheat flour, glucomannan, activated gluten, and emulsifying agent. The one without salt had better quality. Among 6 kinds of packing materials, OPP/Al/PE composite level film demonstrated the best quality packing materials.

• Journal of the Korean Society of Food Science and Nutrition
• /
• 제32권3호
• /
• pp.450-457
• /
• 2003

This study was conducted to investigate the effects of high amylose corn starch consumption on plasma, liver and feces lipid profiles and immune responses in male Sprague-Dawley rats. Experimental animals were fed on diets containing the high amylose starch (HAS,0, 125, 250,500 g/kg diet) for 4 weeks. HAS intake did not affect on food intakes and food efficiency ratio. Final body weights were lowered in HA100 group than in control group. HAS intakes dose dependently increased the weights of cecum and excretion of feces per day, and decreased the pH of cecum contents. And HAS intakes significantly decreased the plasma total lipid, triglyceride and total cholesterol levels. But there were not significant differences total lipid, triglyceride and cholesterol concentrations in liver. The absolute and relative weights of thymus and spleen, plasma Is G and $C_3$ concentrations were unaffected by experimental diets. The splenocyte proliferations with low dose Con A (0.1$\mu\textrm{g}$/10 $\mu$L) as lower in HA25 group and HA50 group than in control group. These results demonstrate that high amylose corn starch intakes significantly improve lipid profiles in plasma.

• Korean Journal of Food Science and Technology
• /
• 제46권6호
• /
• pp.682-688
• /
• 2014

The in vitro digestibility and molecular and crystalline structures of rice starches (Seilmi, Dasan1, and Segoami) with differing amylose content were investigated. Segoami had the highest amylose content (30.9%), whereas Dasan1 had the lowest amylose content (21.2%). The molecular weight ($\bar{M}_w$) of amylose and amylopectin in Segoami was much lower than that of the other two rice starches. Segoami had the highest proportion (8.7%) of amylopectin short branch chains (DP 6-12) and the lowest proportion of B1 chains (DP 13-24). The relative crystallinity, intensity ratio of $1047-1022cm^{-1}$ (1047/1022) and gelatinization enthalpy followed the order: Segoami>Seilmi~Dasan1. Segoami showed substantially low pasting viscosity. Rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) contents showed the highest value in Seilmi, Dasan1, and Segoami, respectively. The expected glycemic index (eGI) of Segoami was lower than that of the other two rice starches. Overall results suggested that the digestibility of rice starch could be highly influenced by their molecular and crystalline structure.

• Journal of Microbiology and Biotechnology
• /
• 제29권5호
• /
• pp.765-775
• /
• 2019

A new ${\alpha}$-amylase-encoding gene (amySL3) of glycoside hydrolase (GH) family 13 was identified in soda lake isolate Alkalibacterium sp. SL3. The deduced AmySL3 shares high identities (82-98%) with putative ${\alpha}$-amylases from the genus Alkalibacterium, but has low identities (<53%) with functionally characterized counterparts. amySL3 was successfully expressed in Escherichia coli, and the recombinant enzyme (rAmySL3) was purified to electrophoretic homogeneity. The optimal temperature and pH of the activity of the purified rAmySL3 were determined to be $45^{\circ}C$ and pH 7.5, respectively. rAmySL3 was found to be extremely halophilic, showing maximal enzyme activity at a nearly saturated concentration of NaCl. Its thermostability was greatly enhanced in the presence of 4 M NaCl, and it was highly stable in 5 M NaCl. Moreover, the enzyme did not require calcium ions for activity, and was strongly resistant to a range of surfactants and hydrophobic organic solvents. The major hydrolysis products of rAmySL3 from soluble starch were maltobiose and maltotriose. The high ratio of acidic amino acids and highly negative electrostatic potential surface might account for the halophilic nature of AmySL3. The extremely halophilic, calcium-independent, and surfactant-resistant properties make AmySL3 a promising candidate enzyme for both basic research and industrial applications.

• Applied Biological Chemistry
• /
• 제31권3호
• /
• pp.249-254
• /
• 1988

Physicochemical properties of starches from the rices of Akibare, Samgang and Mahatma and hardness of the cooked rice were examined Water binding capacity and amylose content were heigher in Samgang. Peak viscosity and breakdown were heigher in order of Akibare, Samgang and Mahatma, while consistency and set back were reverse order. Hydrolytic patterns of three starches with 2.2N HCl at $35^{\circ}C$ showed two distinct stages. Hydrolysis extent of Mahatma starch was lower than those of Akibare and Samgang starches. The relative crystallinities of these starches were heigher in order of Mahatma, Akibare and Samgang. Mahatma was more resistant to heat and acid treatments, lower in water binding capacity and harder when it was cooked.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.217-217
• /
• 2022

Pullulanase (PUL), a debranching enzyme, has been utilized in hydrolyzing the a-1,6 glucosidic linkages in starch, amylopectin, pullulan, as well as related oligosaccharides. It has also been indicated that PUL is a novel indicator of inherent RS (Resistant Starch) formation in rice. In this study, we performed haplotype analysis on 320 bred rice accessions, and additional 54 wild accessions were added to study genetic diversity along with other population-based analyses of the PUL gene. Through these investigations, we summarized a total of 10 functional (non-synonymous) SNPs from 7 different exons on chromosome 4. There were 10 haplotypes, of which only six haplotypes were functional, implicating different subpopulations. Diversity reduction was noticed in temperate japonica (0.0005) compared to the highest one (aus, 0.0154), illustrating their higher genetic differentiation by F_ST-value (0.926). The highest Tajima^ D value was observed in indica (3.6613), indicating PUL gene domestication signature under balancing selection, while the lowest Tajima's D value was found in temperate japonica (-2.2191) which might have undergone under positive selection and purified due to the excess of rare alleles. PCA, population structure, and phylogenetic analyses provide information on the genetic relatedness between and or among the cultivated subpopulations and the wild based on PUL genomic region.

• Journal of Microbiology and Biotechnology
• /
• 제25권2호
• /
• pp.178-184
• /
• 2015

This work aims to utilize wastes from the potato starch industry to produce single-cell protein (SCP) with high lysine content as animal feed. In this work, S-(2-aminoethyl)-_L-cysteine hydrochloride-resistant Bacillus pumilus E1 was used to produce SCP with high lysine content, whereas Aspergillus niger was used to degrade cellulose biomass and Candida utilis was used to improve the smell and palatability of the feed. An orthogonal design was used to optimize the process of fermentation for maximal lysine content. The optimum fermentation conditions were as follows: temperature of 40℃, substrate concentration of 3%, and natural pH of about 7.0. For unsterilized potato starch wastes, the microbial communities in the fermentation process were determined by terminal restriction fragment length polymorphism analysis of bacterial 16S rRNA genes. Results showed that the dominant population was Bacillus sp. The protein quality as well as the amino acid profile of the final product was found to be significantly higher compared with the untreated waste product at day 0. Additionally, acute toxicity test showed that the SCP product was non-toxic, indicating that it can be used for commercial processing.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• 제63권4호
• /
• pp.304-313
• /
• 2018

The objective of this study was to investigate the resistance starch(RS) content and in vitro hydrolysis index of roasted rice flours for low GI food development. This study used intermediate and high amylose rice varieties containing resistant starch. The intermediate amylose rice varieties 'Ilmi' and high amylose rice varieties, 'Goami4' and 'Dodamssal' were tested. The crude fat and crude protein contents of the rice cultivars ranged 2.12~3.08% and 6.2~7.63%, respectively. The RS and amylose contents of Dodamssal and Goami4 were higher than those of Ilmi. RS content of Ilmi was not significantly different before and after roasting treatment. The RS content of Goami4 before roasting was significantly higher than that of Dodamssal, but the RS content of Dodamssal was higher than that of Goami4 at temperatures above $210^{\circ}C$ of roasting. The soluble starch decreased after roasting in Goami4 and Dodamssal. Starch hydrolysis index (HI) and expected glycemic index (GI) were higher in order of Imi, Goami4 and Dodamssal regardless of roasting treatment. The sensory evaluation showed high scores in Dodamssal for color, flavor, bitter taste, bitter taste, sweet taste and sweetness at $240^{\circ}C$ for 10 min and $210^{\circ}C$ for 30 min. The results of this study indicate that Dodamssal was suitable varieties for powder meal with low GI.