• Korean Journal of Food Science and Technology
• /
• v.39 no.2
• /
• pp.138-145
• /
• 2007

The effects of amylopectin and hydrocolloid (locust bean gum and guar gum) content on wheat flour dough and noodle properties were investigated. As the amount of amylopectin increased, the water absorption rate (farinograph), the tension (tension test), the gel stability (freeze-thawing treatment), and the springiness and the cohesiveness (TPA) increased, but the pasting temperature (RVA), the lightness and yellowness (color measurement), and the hardness (TPA) tended to decrease. In sensory evaluations, the scores for cohesiveness, springiness, and acceptability of cooked noodle increased as the proportion of amylopectin increased. The proper combination of amylose/amylopectin ratio and hydrocolloids improved the freeze-thaw stability and the sensory acceptability of wheat flour dough and noodle.

• Applied Biological Chemistry
• /
• v.37 no.2
• /
• pp.65-71
• /
• 1994

Chungkook-Jang was produced by fermenting Bacillus licheniformis CN-115. The changes of chemical composition, enzyme activity, and amino acids during the fermentation were investigated. The proximate composition was shown irregular fluctuation phenomenon during the fermentation, but only the moisture tended some reducing during the fermentation just after steaming. The content of amino nitrogen was increased radically after the 36 hours of fermentation and became the highest level at 18.072 mg/g at the 60 hours of it. In accordance with the fermentation of Chungkook-Jang, pH got to the 8.39 at 60 hours with increasing, protease activity was increased according to the fermentation and acid and neutral protease activity was reduced after being reached at the highest activity at 48 hours. The most suitable pH was 6.5 and temperature was $35^{\circ}C$ for dissolution-activated of protein in the process of fermentation of Chungkook-Jang. The content of water soluble protein and the content of salt soluble protein were increased at continuously according to the fermentation time of Chungkook-Jang the largest quantity. The molecular weight of water soluble protein of Chungkook-Jang fermented for 48 hours was about 19,000. The amino acids of water soluble protein just after steaming were totally 16 kinds and proline was amino acid and them was in series by glutamic acid and serine in that ordered. The amino acids salt soluble protein, just after steaming were totally 16 kinds and was the largest quantity phenylalanine, glutamic acid and aspartic acid and aspartic acid in that order.

• Food Science of Animal Resources
• /
• v.29 no.3
• /
• pp.364-373
• /
• 2009

This study was conducted to provide fundamental information in developing muscle-specific strategies to improve the quality and value of low-fat pork cuts upon evaluating meat qualitative parameters of twenty one (21) muscle samples selected from ten (10) market-weighted crossbred pigs. The following observations were made. The pH was highest for subscpularis and lowest for gluteus superrificialis (p<0.05); the subscpularis can hold water the most (p<0.05), biceps femoris loses the most content upon cooking, while subscpularis loses the least content (p<0.05); gluteus superrificialis (p<0.05) has the most purge loss contents, and infraspanatus and gastrocneminus contained the most collagen, while adductor had the least collagen (p<0.05); biceps femoris has the most WB-shear force values while subscpularis (p<0.05) has the least; pectoralis profundi-fan was the most protein soluble; semitendinosus has the most gel strength (p<0.05). In the properties of meat color, tensor fasciae latae shows the highest CIE $L^*$ (lightness) values (p<0.05) and supraspinatus, brachiocephalicus and infraspanatus have the highest CIE $a^*$ (redness, p<0.05) values; vastus intermedius has the most myoglobin content while longissimus dorsi (p<0.05) has the least; infraspanatus is the most tender (one of the sensory properties) while biceps femoris was the most tough among all tested muscles (p<0.05); the pectoralis profundi-fan was the most flavorful pork while vastus intermedius was the least (p<0.05); supraspinatus, infraspanatus, semitendinosus, and vastus intermedius were juiciest while longissimus dorsi was the driest (p<0.05). In overall likeness, the semitendinosus and infraspanatus were most liked while biceps femoris and longissimus dorsi were the least (p<0.05). This study presents the results of several parameters in selected pork muscle samples which are useful information for developing new muscle-specific strategies to improve the quality of consuming meat and meat products.

• Journal of agriculture & life science
• /
• v.50 no.4
• /
• pp.91-98
• /
• 2016

This aim of the present study was to evaluate the effects of phosphate on the quality properties of the surimi-like materials. Surimi-like materials as a control was prepared with beef heart by three times of washing treatment. Three types of surimi-like materials were manufactured by different conditions(T1: 2% salt, T2: 1.95% salt+0.05% phosphate, T3: 1.90% salt+0.10% phosphate). The moisture content was significantly lower in T1 than the control, and T3 sample had the highest crude protein content(P<0.05). The cooking loss was significantly lower in T2 than the control, and T2 sample had the highest water-holding capacity(P<0.05). The lightness and whiteness values were significantly lower in the treatment samples compared to the control sample; whereas redness values was higher than the control(P<0.05). Beef heart surimi-like materials added with salt and phosphate had higher in texture properties in the control, and T3 sample had the highest hardness, cohesiveness, gumminess and chewiness values(P<0.05). Therefore, the addition of phosphate could increase the protein content and gel properties as well as water-holding capacity of surimi-like materials from beef heart.

• Journal of Life Science
• /
• v.25 no.9
• /
• pp.1027-1035
• /
• 2015

A strain GP32 which produces a highly viscous extracellular polysaccharide was conducted with soil samples and identified as Pseudomonas species. The culture flask conditions for the production of extracellular polysaccharide by Pseudomonas sp. GP32 were investigated. The most suitable carbon and nitrogen source for extracellular polysaccharide production were galactose and (NH₄)₂SO₄. The optimum carbon/nitrogen ratio for the production of extracellular polysaccharide was around 50. The optimum pH and temperature for extracellular polysaccharide production was 7.5 and 32℃, respectively. In batch fermentation using a jar fermentor, the highest extracellular polysaccharide content (15.7 g/l) was obtained after 70 hr of cultivation. The extracellular polysaccharide produced by Pseudomonas sp. GP32 (designated Biopol32) was purified by ethanol precipitation, cetylpyridinium chloride (CPC) precipitation, and gel permeation chromatography. Biopol32, which has an estimated molecular weight of over 3×10⁷ datons, is a novel polysaccharide derived from sugar components consisting of galactose, glucose, gulcouronic acid and galactouronic acid in an approximate molar ratio of 1.85 : 3.24 : 1.00 : 1.42. The solution of Biopol32 showed non-Newtonian characteristics. The viscosity of Biopol32 exhibited appeared to be higher at all concentration compared to that of zooglan from Zoogloea ramigera. An analysis of the flocculating efficiency of Biopol32 in industry wastewater (food, textile, and paper wastewater) revealed chemical oxygen demand (COD) reduction rates 58.4-67.3% and suspended solid (SS) removal rates 82.6-91.3%. Based on these results, Biopol32 is a possible candidate for industrial applications such as wastewater treatment.

• Microbiology and Biotechnology Letters
• /
• v.26 no.4
• /
• pp.323-330
• /
• 1998

Cyclodextrin glucanotransferase (CGTase) was purified from the culture broth of the Bacillus firmus var. alkalophilus, using ultrafiltration, starch adsorption/desorption, ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephacryl HR-100. The molecular weight of the purified enzyme was determined as 77,000 by SDS-PAGE. The optimum pH and temperature for the CD synthesis were 6.0 and 5$0^{\circ}C$, respectively. The activity of this enzyme was stably kept at the range of pH 6.0～9.5 and up to 5$0^{\circ}C$. However, in the presence of $Ca^{2+}$, the optimum temperature for CD synthesis was shifted 55~6$0^{\circ}C$ and this enzyme was stable up to 6$0^{\circ}C$ because of the stabilizing effect of $Ca^{2+}$. The purified CGTase produced CDs with high conversion yields of 45~51% from sweet potato starch, com starch and amylopectin as substrate, especially, and the product ratio of $\beta$-CD to ${\gamma}$-CD was obtained at range of from 5.8:1 to 8.4:1 according to the kind of substrate. The purified enzyme produced mainly $\beta$-CD without accumulation of $\alpha$-CD during enzyme reaction using various starches as the substrate, indicating that the purified enzyme is the typical $\beta$-CGTase. The purified CGTase produced 25 g/l of CDs from 5.0% (w/v) liquefied com starch and the conversion yield of CDs was 50%, and the content of $\beta$-CD was 84% of total CDs after 8 hours under the optimum reaction condition.ion.

• Korean Journal of Food Science and Technology
• /
• v.32 no.4
• /
• pp.755-762
• /
• 2000

Physicochemical properties of commercial sweet potato starches manufactured by 7 different companies were investigated in comparison with corn and potato starches. Crude ash and protein content varied from 0.36 to 1.02%, and from 0.04 to 0.14% based on dry weight, respectively. The protein contents were relatively smaller than that of corn or potato starch. But whiteness of the sweet potato starches was less than that of corn or potato starch. Mean diameter of the sweet potato starch granules varied from 14.23 to $21.08\;{\mu}m$ depending on the company and all sweet potato starches showed bimodal size distributions. Pasting viscosity measured by Rapid Viscoanalyzer(RVA) also showed variations among the starches of different companies. The starch from D company in Korea had the lowest pasting temperature$(74.00^{\circ}C)$ whereas the starch from a phillippine company(P) did the highest one$(80.35^{\circ}C)$. The peak viscosity of sweet potato starches was higher than that of corn starch but lower than that of potato starch. The D company starch also showed the highest peak viscosity(2283 cp) among the starches tested. Paste breakdown by hot shearing ranged from 524 cp (S company) to 1279 cp (HL company). Textural properties of the starch gels appeared significantly different among the starches of different manufacturers. The greatest hardness of the gel was $137.90\;g_{f}$ at 1 day storage whereas the lowest value was $31.53\;g_{f}$. Except the starches from 2 companies (P and S), the sweet potato starches formed very soft and weak gels. P or S company starches formed the gels similar to potato starch. Syneresis by freeze-thawing treatments appeared less for sweet potato starch gels than that for corn starch gels, but greater than that for potato starch gel. The overall properties of the sweet potato starches varied by the manufacturing companies, and ranged between those of corn and potato starches.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.6
• /
• pp.684-696
• /
• 1995

A mutant for chalky endosperm and genetic male sterility (GMS) was newly developed in rice. The two characters were found to be controlled by single recessive gene which has pleiotropic effect, indicating that chalky seeds should be GMS seeds in segregating populations. Chalky seeds showed the same shape and size as normal seeds. However, starch composition of central part of endosperm was looser and shape of starch granules was rounder compared with normal endosperm, resulting in significantly lower grain weight, absolute density and grain hardness in chalky grains than in normal ones. Amylose content and gel consistency of chalky grains were much lower and harder, respectively. Male sterile plants showed much shorter plant height, poorer panicle exsertion and lesser panicle number compared with normal plants. Microspore abortion stage in pollen developmental process was observed as before meiosis. Male sterility of the mutant was stable regadless of temperature and day length. A system breeding hybrid rice using this mutant was discussed, comp ring with other systems utilizing cytoplasmic-genic male sterility(CGMS) and environment sensitive GMS(EGMS). Separation of GMS seeds in mixed seed bulks by specific gravity (1.14∼1.16g / cm3) was successful about 85∼90%. But some mixed normal plants were seemed to be easily removed by the apparent difference in growth characters at seedling stage. The highest natural outcrossing rate of this GMS line was as 17.3 % in a plot treated with 2-row pollinator, I-row GMS, and GA3 + cutting of flag leaf + pollen-scattering by rope.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.35 no.1
• /
• pp.34-43
• /
• 1990

Six commerical rice varieties were cultivated and harvested at different locations in 1987 and 1988 to clarify the degree of locational variations. of several characteristics related to rice grain quality using the rice samples harvested from 8 to 20 locations for a variety each year. Locational variations of percent brown rice, percent milled rice, 1000-grain weight and amylose content were small, but whole grain rate, alkali digestibility, gel consistency, percent white-center and white-belly grain, degree of chalkiness and degree of translucency showed larger variations between locations. The degree of locational variation of sensory evaluation score for eating quality of cooked rice were varied from small to large along with rice variety used and year cultivated. Texture palatability index and stickiness of cooked rice among rheogram characteristics showed larger locational variations, but cohesiveness and springiness showed smaller variations between locations. Set back, break down and maximum viscosity showed larger locational variations among amylogram characteristics of rice flour. Special attention was given to a cultivated location, Anseong, because rice samples harvested at Anseong showed lower percent white-center and white-belly grain, and low set back and high break down in Chucheongbyeo, lower percent white-center and white-belly grain, higher texture palatability index and viscousness/hardness ratio, and low set back and high break down in Dongjinbyeo, higher texture palatability index, and low set back and high break down in Yongmunbyeo, lower percent white-center and white-belly grain in Sangpungbyeo, and low set back and high break down in Samkangbyeo. No other locations in this study produced rice samples showing wide acceptable quality-related characteristics except Anseong.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.1
• /
• pp.27-35
• /
• 1986

In succession to the previous paper, the present study was directed to investigate the effect of keeping freshness of conger eel (Astroconger myriaster) and yellowtail (Seriola quinqueradiata) by partial freezing, and the changes in the physical properties of fish meat paste product prepared with the muscle of conger eel during storage were also examined. The results obtained are summarized as follows: The period of keeping freshness (days in which k value reaches $20\%$) of conger eel and yellowtail by partial freezing was 10 days and 6 days, respectively. VBN content in the conger eel muscle showed 39.5 mg/100g by icing for 15 days, and did not show a great change by partial freezing and freezing, while that of yellowtail muscle reached at 32 mg/100g by icing, 20 mg/100g by partial freezing and 18 mg/100g by freezing for 15 days. The lipids extracted from the muscles of both fishes by icing were remarkably oxidized than those by partial freezing. The myofibrillar protein in the conger eel muscle during storage for 9 days decreased $3\%,\;10%\;and\;11\%$ by icing, partial freezing and freezing, respectively, and that of yellowtail muscle did $16\%,\;10%\;and\;4\%$ by icing, partial freezing and freezing, respectively. On the other hand, the alkali-soluble protein in both fishes increased with storage time. Gel strength of fish meat paste product prepared with the muscle of conger eel decreased to $35\%$ by icing, $74\%$ by partial freezing and $76\%$ by freezing for 10 days compared to control, and the expressible water increased 1.6 times, 1.2 times and 1.1 times by icing, partial freezing and freezing, respectively, as much as that of control product.