• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.648-652
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• 2002

Removing shup from oyster by aeration method and coating with edible coating materials were investigated to improve oyster quality for the retort processing. Aeration rate and pore size of nozzle were critical factors to remove shup by aeration method. Optimum aeration rate and nozzle size were 45 L/min and 0.4 mm, respectively, when aeration was peformed two times and each operation maintained for 1 minute. Sodium alginate (SA) was used for oyster as the basal coating material. However, SA affected mouth-feel when it was applied at high concentrations. Sub-coating materials including skim milk, waxy corn starch, Purity CSC, white corn starch and carboxymethylcellulose (CMC) in decreasing order showed a positive effect on improving coatability and mouth-feel. Therefore, it is suggested that 1.5% SA and 0.9% skim milk should be the optimum composition of coating materials for oyster. Browning and syneresis of the porridge containing the coated oyster were considerably inhibited as compared with the sample without the coated oyster.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.6
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• pp.889-893
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• 2016

This study was carried out to investigate the physicochemical and fermentation properties of yogurt made from high pressure processing (HPP) treated milk. Raw milk and commercial yogurt starter were used to make yogurt. Raw milk was HPP treated at 350 or 450 MPa (HPP 350 or 450) for 15 min or heat treated at $80^{\circ}C$ for 10 min. The numbers of lactic acid bacteria of the HPP treated group (HPP yogurt) rapidly increased during 2~4 h, whereas there was not significant difference from control (P<0.05). Titratable acidity of all samples increased, and pH decreased during storage from 0.99 to 1.24%, as well as from 4.59 to 4.20, respectively. It is confirmed that these values are in general ranges for yogurt. Control showed higher viscosity than HPP 350. Syneresis was significantly lower than that of the control (P<0.05). Based on the data obtained from the present study, HPP treatment was effective to enhance the quality of yogurt.

• Culinary science and hospitality research
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• v.20 no.3
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• pp.113-124
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• 2014

This study investigated the quality characteristics of Yanggeng sweetened with various amounts of trehalose (0, 40, 60, 80, 100 % of trehalose) and their changes during storage times. The moisture content, color value, $^{\circ}Brix$, pH, texture profile, QDA and acceptance for samples were tested. As a result of the mechanical tests, moisture content and pH were increased while hardness were decreased with increased trehalose content. Also, moistness, gloss and after taste were increased with increased trehalose in the sensory attribute difference test. Acceptance test showed Yanggeng with 60% trehalose and 40% sucrose obtained the highest scores on flavor, taste and overall acceptability. During storage in refrigerator, Yanggeng sweetened with higher % of trehalose showed significantly higher moisture content, and lower syneresis and hardness than the control sweetened with only sucrose. The results of the sensory test showed that 60% trehalose Yanggeng was the highest in flavor, after taste, and overall acceptability.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.593-600
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• 2014

Normal rice starch (NRS) possesses high gelling and retrogradation tendencies, with poor freeze-thaw stability. This study investigated the effects of partial replacement of waxy rice starch (WRS) with gums on the pasting and viscoelastic properties as well as the freeze-thaw stability of the WRS paste. Xanthan gum (XAT), locust bean gum (LBG), and their mixtures were individually mixed with WRS at a ratio of 1:19 (w/w). WRS-gum mixtures were pasted using a rapid visco-analyzer at 5% total solid content, and analyzed with respect to the pasting and viscoelastic characteristics, and freeze-thaw stability. Pasting properties of WRS were retarded in pasting temperature and enhanced in pasting viscosity (although peak viscosity was varied) by partial replacement with gum and gum mixtures. Storage moduli of WRS-XAT:LBG pastes became similar to those of NRS paste with increasing angular frequency from 1 to 10 rad/s. Finally, WRS-XAT and WRS-XAT:LBG possessed more enhanced freeze-thaw stability than NRS.

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