• Fisheries and Aquatic Sciences
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• v.26 no.9
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• pp.535-547
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• 2023

Sea cucumbers (Holothuria scabra), also known as beche-de-mer, are highly valued as a luxurious food item and have been utilized as a traditional tonic food in various Asian countries for centuries. The body walls of sea cucumbers are the main edible part, which are primarily composed of glycosaminoglycan (GAG). The rehydration of dried sea cucumber is a crucial step prior to further processing. The aim of this study was to assess the impact of ultrasound-assisted rehydration (UAR) on the quality of dried sea cucumbers. The experiment used four different rehydration methods, including conventional methods at 27℃ (KV27℃) and 15℃ (KV15℃), as well as a combination of ultrasound at 27℃ with conventional at 15℃ (UAR27 + KV15℃) and ultrasound at 15℃ with conventional at 15℃ (UAR15 + KV15℃). Results indicated that the rehydration rate (RR) was significantly affected by both the rehydration method and the temperature used (p < 0.05). UAR27 + KV15℃ was identified as the most effective method in terms of rehydration behavior and quality characteristics of dried sea cucumber, with a RR of 0.58 ± 0.53 gH₂O/hour and reduced rehydration time of up to 28 hours. Moreover, the UAR27 + KV15℃ method demonstrated superior rehydration potential, nutritional value (proximate composition and sulfate content), color, lower energy, and microstructure properties compared to the other methods. The sulfate content and yield of sulfated GAGs were determined to be 89.4 mg/g and 52.8 ㎍/g, respectively. Confirmation of the absorption band of the sulfate group showed the presence of 3-N-acetyl galactosamine at a wavelength of 1,269 cm^-1 and C-O-S at 860 cm^-1. The sea cucumbers treated with UAR exhibited a GAG content approximately 2.9 times higher than those rehydrated with the conventional method. Eventually, the combination of UAR at 27℃ with conventional at 15℃ methods can significantly accelerate the rehydration of sea cucumber without negatively affecting its physical quality properties.

• The Korean Journal of Food And Nutrition
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• v.4 no.1
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• pp.1-8
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• 1991

This study was attempted to establish the basic data for effective utilization of the dried radish and sweet potato. The rehydration characteristic was carried out from these dried root vegetables in various conditions. The following results were obtained. The rehydration value was increased in glycine solution, whereas It decreased in lactic acid solution. Also the vacuum freezing was higher than that in hot air drying, and it was higher the slow freezing than in the quick freezing. The rehydration rate and the rehydration surface area curve were composed of three stages, and these stages were corresponded to each other. At the range of initial immersion to 2min., the largest rehydration rate was showed. The activation energy obtained from the Arrhenius plot of the rehydration rate constant(K) were 3. Bx103ca11g mol and 3.7$\times$103cal/g mol for dried radish and sweet potato, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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• pp.87-92
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• 1998

Major characteristics of shrinking and rehydration of Korean tea-leaves were investigated in the hot-air drying equipment. Experiments were performed with various drying temperature, plucking time, heating method and rolling condition. The values of shrinking raito and rate were the highest at 7$0^{\circ}C$ in the range of 3$0^{\circ}C$ to 9$0^{\circ}C$. The 1st tea-leaves and showed higher values. Shrinking ratio was 16.62 and 19.62% for leaves and stems; shrinking rate was found 0.083 and 0.091cm/hr.cm, respectively. The rehydration characteristics of tea-leaves at the drying temperature of 3$0^{\circ}C$ were fairly satisfactory. The 2nd tea-leaves showed higher value than others, while the natural tea-leaves were lower. Average rehydration ratio and rehydration rate constant were 85.7% and 0.063/min for leaves; 80.1% and 0.032/min for stems, respectively.

• Food Science and Preservation
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• v.8 no.3
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• pp.313-319
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• 2001

In order to produce the high quality rehydrated acorn Mook(Korean tradition gel flood) that enhance acceptability, the optimum condition was investigated for the rehydration process of dried Monk as salt concentration(0, 1, 2%), temperature(20, 70, 80, 90$^{\circ}C$) and time. The estimation of moisture gain, rehydration efficiency was analyzed statistically. The surface color md seniory evaluation were undertaken to evaluate the rehydrated Mook quality The optimum rehydration time was decided to 15 minutes and it takes 3 minutes for the cooling tilde. The moisture gain increased as the rehydration temperature increase. And the moisture gain and moisture gain rate were higher at 1% salt solution than other concentration. As the rehydration efficiency, surface color and sensory properties of rehydrated Mook, 1% salt treatment was superior.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.82-88
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• 2011

This study was carried out to investigate the optimum conditions for extraction of soluble acidic polysaccharides from ginseng marc. Method of carbazole-sulfuric acid was applied to determine the amount of acidic polysaccharides in ginseng marc. The amounts of soluble acidic polysaccharides in water extract of ginseng marc were increased with increasing extraction temperature. The contents of acidic polysaccharides were not significantly different despite the extraction time increasing from 0.5 hours to 6 hours. To estimate the rehydration rate of the freeze dried polysaccharide, the extracted acidic polysaccharide fraction powder was determined the amount of soluble acidic polysaccharides by carbazole-sulfuric acid method again. The rehydration rate of acidic polysaccharides from water-extract of red ginseng marc at room temperature was 100%. On the other hand, the rehydration rate of acidic polysaccharide of red ginseng marc at boiling temperature was about 50%. The rehydration rate of acidic polysaccharides from water-extract of white ginseng marc at room temperature was 50%. The rehydration rate of acidic polysaccharide of red ginseng marc at boiling temperature was about 40%. The rate of soluble acidic polysaccharide of Red Ginseng is higher than that of White Ginseng. We can find out the maximum extraction method of soluble acidic polysaccharide from ginseng marc.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.153-163
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• 2021

This study was conducted to examine the effects of starch noodles (dangmyeon; SNs) with different starch sources and porcine intestines (PIs) with different pH on the rehydration stability of Korean blood sausage (sundae). Mungbean SN3 and PI3 (pH 9.18) showed significantly higher values of 80.69%-91.67% and 79.66%-80.98%, respectively, regardless of the drying methods (hot air, vacuum and freeze drying) (p<0.05). A number of larger pores were observed only in the cross-section of the freeze dried SN and PI through SEM. SN2 (potato starch) and PI3 (pH 9.18) showed lower expansion (⁎ΔL 6.90 mm) and higher expansion ratio (⁎ΔL 26.29 mm), respectively, after rehydration of freeze dried sample (p<0.05). From the application of SN2 (potato starch) and PI (0.5%-2.0% Na-pyrophosphate) to freeze dried sundae manufacturing, higher rehydration stability of more than 91.5% was obtained. These results suggested that potato SN and treatment of PI with Na-pyrophosphate is useful for desirable rehydration stability of freeze dried sundae.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.395-400
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• 2001

The objectives of this study are to establish efficient pretreatment concentration and rehydration process for the production of the high quality of freeze-dried Mook, a traditional gel food in Korea, as an instant food. Effect of immersion in sucrose solution as pretreatment before freeze-drying on the rehydration efficiency and quality characteristics was studied. The rehydration efficiency of non-treated Mook was the highest. The rehydration efficiency increased as the concentration of sucrose increased. The texture of rehydrated Mook treated in sucrose solution was decreased with increase in rehydration temperature. The Mook treated at 60% sucrose solution was somewhat similar to the market selling Mook in the quality and the treatment prevented color and texture degradation.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.383-389
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• 2016

Purpose: This study was conducted to evaluate the effect of rehydration and subsequent heating at high temperature on the pigments and antioxidants of dried samnamul (Aruncus dioicus) and daraesoon (Actinidia arguta). Methods: Rehydration included 16 h-soaking in cold water, and 30 min-boiling and 1 h-infusion in water. Rehydrated samnamul and daraesoon were heated at $180^{\circ}C$ for 10 or 20 min with or without perilla oil addition (10%) for cooking. Pigments and antioxidants were determined by HPLC and spectrophotometry. Results: Rehydration caused decreases in pigment and polyphenol contents, but increase in tocopherol content. Cooking by heating without addition of perilla oil resulted in increases in chlorophyll and carotenoid contents, but decreases in polyphenol and tocopherol contents. Decrease in tocopherol content by heating at $180^{\circ}C$ was reversed by the addition of perilla oil. Conclusion: This study strongly suggested that cooking of samnamul and daraesoon at $180^{\circ}C$ with perilla oil could improve color, texture, and potential health functionality by recovering the loss of antioxidants and pigments with antioxidant activity.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.512-515
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• 1995

In order to examine the effect of rehydration methods on viability after freeze-drying of Streptomyces aureofaciens, we labeled the DNA of S. aureofaciens with $^3H-adenine$. Extracellular radioactivity levels appeared to be high in the rehydrated solutions after freeze-drying than freezing-thawing. In effects of rehydration after freeze-drying, the viability of the cell appeared about 20% in case of with admitting air at single ampule, but that of which appeared about 91% in case of without admitting air at double ampule. Thus, S. aureofaciens cells were damaged during the process of rehydration after freeze-drying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.3
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• pp.195-200
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• 1990

Effects of cooking time(5-30 min in a pressure cooker) and HTST air dehydratiion time(0-9min at 15$0^{\circ}C$) on physical properties of dried green peas(3% oisture content wet basis) were investigated by determining rehydration ratio rehydration curve browning reaction and puncture force, The rehydration ratio and curve of dried green peas were increased with increa-sing cooking time and HTST air dehydration time. Preheating of the green peas for 30 min in a pressure cooker or for 9 min of HTST air dehydration time prior to 6$0^{\circ}C$ air dehydration recovered a 87.3% of original moisture content of raw green peas in a boiling water for 5 min. The brownin greaction was gradually decreased up to 15 min of cooking time. Puncture pressure of rehydrated green peas treated in a boiling water for 5 min was decreased as the cooking time and HTST air dehydration time were increased and was highly correlated with rehydration (r=-0.956) The effects of cooking time and HTST air dehydration time on rehydration ratio browning reaction and puncture pressure were significantly different at the a=0.01 level except effect of HTST air dehydration time on browning reaction.