• Food Science and Biotechnology
• /
• v.18 no.1
• /
• pp.118-123
• /
• 2009

In order to find out the effect of low level of starch acetylation on physicochemical properties of potato starch, amylose content, digestibility of raw and gelatinized starch, thermal properties, pasting properties, and the swelling power of native and acetylated potato starches were measured. The amylose content was significantly lower in acetylated starch than in their counterpart native starches. Though a tendency in the decrease in digestibility of raw starch was observed with starch acetylation, acetylation did not alter the proportion of readily digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) of both raw and gelatinized potato starches. No clear increase in the swelling power was observed, however, the peak and onset gelatinization temperatures and the enthalpy required for starch gelatinization decreased with starch acetylation. Peak and breakdown viscosities were reduced due to acetylation of potato starch while final viscosity and set back were increased.

• Fisheries and Aquatic Sciences
• /
• v.14 no.4
• /
• pp.311-315
• /
• 2011

A 7-week feeding trial was conducted to investigate the effect of dietary starch level and kind on the growth and body composition of juvenile olive flounder. Triplicate groups of fish (average weight: 1.5 g) were fed iso-nitrogenous (48% crude protein) and isocaloric (4.8 kcal/g diet) diets containing 15-25% ${\alpha}$-potato starch and 15% ${\beta}$-potato starch. Survival was not affected by dietary starch level and kind. The weight gain of fish fed the diet containing 20% ${\alpha}$-potato starch was significantly higher than that of fish fed the diets containing 15% and 25% ${\alpha}$-potato starch levels. The feed efficiency and protein efficiency ratios of fish fed the diets containing 15% ${\beta}$-potato starch were significantly lower than those of the other groups (P < 0.05). The protein efficiency ratio tended to increase with increasing ${\alpha}$-potato starch. The daily feed intake of fish fed the diet containing 15% ${\beta}$-potato starch was significantly higher than that of the other groups (P < 0.05). The hepatosomatic index, condition factor, and proximate composition of the whole body were not affected by the dietary starch level and kind. These results indicate that up to 20% ${\alpha}$-potato starch could be incorporated into the juvenile flounder diet for optimum growth.

• Korean journal of food and cookery science
• /
• v.18 no.6
• /
• pp.593-602
• /
• 2002

The objective of this study was to investigate the sensory and quality characteristics of Gamjeobyung containing different ratios of ingredients such as heated potato flour(30%, 40%, 50%), potato starch(30%, 40%), sugar, honey, and water by sensory evaluation and mechanical examination. The results of sensory evaluation showed that Gamjeobyung containing 30% heated potato flour, and potato starch had higher scores in overall acceptability, color, flavor, grain, moistness, chewiness and sweetness preferance. In the textural analysis of Gamjeobyung, the cohesivenss, springiness, adhesiveness were the highest in the samples with 30% potato starch, and the chewiness, gumminess, and hardness were the highest in the 40% added samples. The hunter's color L value and b-value of Gamjeobyung was decreased and a-value was increased of potato starch. The moisture content of Gamjeobyung was higher in the samples with heated potato flour than the samples with potato starch.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1410-1414
• /
• 1999

The granular size and shape of durian seed starch were $2.0-10.0\;{\mu}m$ and oval and polygonal. Amylose contents of durian seed, corn, sweet potato and potato starch were 28.3%, 27.5%, 20.3% and 21.7%, respectively. Blue value of durian seed (0.370) higher than that of corn (0.368), sweet potato (0.332), and potato starch (0.338). Alkali numbers of durian seed, corn, sweet potato and potato starch were 7.39, 9.02, 7.08 and 5.43, respectively. Swelling power of durian seed starch was similar to that of sweet potato starch. X-ray diffraction patterns of durian seed starch showed an A-type crystalline structure. According to pasting properties by Rapid Visco-Analyzer, the gelatinization temperature of durian seed starch $(76.6^{circ}C)$ was higher than that of corn $(73.0^{circ}C)$, sweet potato $(72.3^{circ}C)$ and potato starch $(70.2^{circ}C)$. The breakdown of durian seed starch were lower than that of corn, sweet potato and potato starch.

• Natural Product Sciences
• /
• v.15 no.3
• /
• pp.134-138
• /
• 2009

In an attempt to establish anti-ulcerogenic activity of potato tubers, inhibitory activity against ethanol- and indomethacin-induced gastric ulcer models in rats was evaluated for the first time. From several varieties of potato tubers including Solanum tuberosum L. cv. Superior (white skin and fresh potato) and two new varieties of (Bora valley and Gogu valley), raw potato juice was prepared and the starch was obtained from each juice by filtration and drying. Upon oral administration to rats, raw potato juice showed more or less inhibitory activity. The starch showed higher and dose-dependent inhibitory activity, suggesting that the active ingredient in raw potato juice may be the starch. Particularly, the starch obtained from the tubers of new potato variety, "Bora valley," with purple color, showed the highest inhibitory activity (62.4% and 37.1% inhibition of ulcer index at 500 mg/kg), while omeprazole (proton pump inhibitor) used as a reference drug showed 74.4% and 75.7% inhibition at 20 mg/kg against ethanol- and indomethacin-induced ulcer formation, respectively. The present study provides a first evidence of anti-ulcerogenicity of raw potato juice and the starch. Especially, the starch from "Bora valley" strongly inhibited ulcer formation in rats. Considering that these are food components, they may be safely used for anti-ulcerogenic nutraceuticals.

• The Korean Journal of Food And Nutrition
• /
• v.9 no.4
• /
• pp.424-429
• /
• 1996

In an attempt to evaluate the effect of six starch sources-potato starch acetate, corn starch acetate, waxy corn starch, corn starch, potato starch, and wheat starch on properties of frozen noodle, amylograph characteristics of starch-wheat flour composites, cooking quality, maximum cutting force and sensory properties of cooked frozen noodles were examined. Compared with 100% wheat flour as control, potato starch acetate and potato starch-wheat flour composites had slightly lower initial pasting temperature and wheat flour composites with acetylated starches, waxy corn starch and potato starch had slightly higher maximum peak viscosity. At cooking quality examination of noodles made from wheat flour-starch composites, volume and weight of cooked noodles were increased and cook loss was decreased with the addition of acetylated starches and waxy corn starch. Maximum cutting forces of cooked frozen noodles containing more than 15% of potato starch acetate and only 15% of corn starch acetate were higher than that of control. Other starches except potato starch improved sensory properties of cooked frozen noodles and the greatest positive effect was acetated potato starch.

• Korean journal of food and cookery science
• /
• v.19 no.6
• /
• pp.772-776
• /
• 2003

This study was performed to determine the quality characteristics of lemon pyun with various kinds of getting agents: agar, gelatin, sweet Potato starch, corn starch and Potato starch. Lemon Pyun was made with lemon juice(21.4％), gelling agent(6.7％), water(53.3％), sugar(13.3％) and honey(5.3％). The quality characteristics of the sample were estimated in terms of pH, color difference, texture profile analysis and sensory evaluation. (Ed- as this is an abstract this introductional clause is unnecessary) The PH of lemon pyun showed no significant difference among the different gelling agents. Lightness was significantly(p＜0.05) lowered in the agar and gelatin groups, a value was significantly(p＜0.05) lowered in the sweet potato starch and potato starch groups, and b value was significantly(p＜0.05) lowered in the sweet potato starch group. In texture profile analysis, chewiness, gumminess and hardness were significantly(p＜0.05) increased in the sweet potato starch group. According to sensory evaluation, elasticity and hardness of the sweet potato starch and cornstarch groups were stronger(p＜0.05) than of other gelling agent groups. Lemon pyun containing sweet potato starch was most preferable in terms of Vitamin C provision.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.2
• /
• pp.423-428
• /
• 1999

Potato starches were hydroxypropylated with 2.5, 5.0, 7.5, and 10.0% propylene oxide(PO) to improve mechanical properties of starch polyethylene film. Starch polyethylene cast films were prepared that contained 5% or 10% of the hydroxypropylated potato starch. Mechanical properties of these films were measured and compared to those of the films containing native potato starch. DS(degree of substitution) increased proportionally as propylene oxide concentration increased. Relative crystallinity in X ray diffraction patterns was decreased and starch granule observed by scanning electron micro scopy was destroyed by severe hydroxypropylation. In color properties of films, b value was not significantly different in the films but 5% starch polyethylene films with 2.5 PO starch showed the lowest L and a value. Tensile strength and strain energy of the films except the film containing 10.0 PO starch were higher than those of the containing native starch.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.1
• /
• pp.126-133
• /
• 2015

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside food when the electrical current is transmitted into. Prior to the study, we have researched the potato starch's thermal property changes during ohmic heating. Comparing with conventional heating, the gelatinization temperature and the range of potato starch treated by ohmic heating are increased and narrowed respectively. This result is appeared equally at wheat, corn and sweet potato starch. At this study, we treated potato, wheat, corn and sweet potato starch by ohmic/conventional method and observed change of external structure by microscope and internal structure by X-ray diffractometer. Conventional heated at $55^{\circ}C$ potato starch was not external structural changes. But ohmic heated potato starch is showed largely change. Some small size starch particle were broken or small particles are made of larger particle together or small particles caught up in the large particle. Changes in ohmic heated potato starch at $60^{\circ}C$ was greater. The inner matter came to an external particle burst inside and only the husk has been observed. The same change was observed in the rest of the starch. The change of internal structure of potato starch was measured using X-ray diffraction patterns. There was no significant difference between ohmic and conventional heating at $55^{\circ}C$. But almost every peak has disappeared ohmic at $60^{\circ}C$. Especially $5.4^{\circ}$ peak to represent the type B was completely gone. When viewed from the above results, external changes with change in the internal crystal structure of the starch particles were largely unknown to appear. In conclusion, during ohmic heating changes of starch due to the electric field with a change in temperature by the heating was found to have progressed at the same time.

• Korean Journal of Food Science and Technology
• /
• v.32 no.6
• /
• pp.1298-1305
• /
• 2000

Potato starches were crosslinked with 0.1, 0.5, 1.0, and 2.0% epichlorohydrin. Starch/polyethylene(PE) cast films were prepared to contain 5% of the crosslinked potato starch. Mechanical properties and degradability of these films were measured and compared to those of the films containing native potato starch. Mechanical strength of the films containing crosslinked potato starch was higher than that of the film containing native starch. Thermal degradability measured by a FT-IR and an Instron showed that crosslinked starch/PE films degraded faster than native starch/PE films. Biodegradability of the starch/PE films was accelerated by the addition of crosslinked starch to the PE films.