• Food Science and Preservation
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• v.22 no.1
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• pp.56-62
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• 2015

In this study, the quality characteristics of different drying methods of Aronia melanocarpa, which contains large amounts of bioactive substances, were investigated for the improvement of their practical use. During the drying period, the weight reduction was the highest with vacuum freeze drying (81.6%). The water content was reduced to the maximum level when vacuum freeze-drying was used. With regard to the color value measurement results, there were no significant differences in the $L^*$ value. Values of $a^*$ and $b^*$ were increased in vacuum freeze drying and cold air drying, but decreased in hot air drying. The hardness was increased dramatically after 36 hours of hot air drying, while with cold air drying, it increased slowly until 132 hr and increased rapidly after 132 hr. The dried yield was the highest with cold air drying (24.2%). As for the general component analysis results of Aronia melanocarpa, the moisture content was the lowest, and the crude protein and crude fat contents were the highest with vacuum freeze drying. No difference in pH value was shown among the dried Aronia melanocarpa obtained from the different drying methods, but the sugar content was the highest with vacuum freeze drying. The mineral content was the highest with cold air drying, and K, Ca, Mg, and Na were the major minerals. The free sugar content of dried Aronia melanocarpa was found to be 5.92~20.59 g/100 g, and the highest free sugar content was found with vaccum freeze drying.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.1
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• pp.62-67
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• 1993

The effect of frozen storage on some physicochemical and sensory quality of salted Chinese cabbage and Kimchi were investigated. The texture of the fresh Chinese cabbage was preserved better by emersion quirk freezing or predrying than by air slow freezing or no predrying while no effect was measured on the salted Chinese cabbage. The salted cabbage had less frozen damages than the fresh one and had the similar texture characteristics of the fermented Kimchi. The frozen Kimchi had the similar overall quality to the unfrozen fermented Kimchi in spite of a little higher chewness values. The color of the salted Chinese cabbage was a little changed to pinkish after 3 months frozen storage but Kimchi was maintained the good quality after 6 months.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1972-1980
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• 2013

The purpose of this study is to evaluate the storage quality characteristics of bread with added dried mulberry pomace (DMP, 0, 1, 3 or 5%) during storage at $4^{\circ}C$ for 7 days. During the entire storage period, the moisture content was higher in breads containing DMP compared with the control bread. Textural properties by TPA showed that the hardness of DMP bread maintained a lower hardness than that of the control during the entire storage period. Moreover, DSC (Differential Scanning Calorimetry) result showed that ${\Delta}H$ (crystal melting enthalpy) of the bread containing DMP was lower than that of the control bread, which indicate the retarding of retrogradation. The sensory preference test results demonstrated that the bread with 3% DMP had higher scores in over-all preference than the others. These results suggest that DMP delays the retrogradation of bread during storage.

• Food Science and Preservation
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• v.17 no.4
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• pp.478-486
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• 2010

The qualities of ginger prepared by an MPD (molecular press dehydration) method using maltodextrin, or dried using reused dehydration liquid, or prepared by freeze-drying or hot-air drying, were compared in terms of approximate overall composition, color, water absorption index, water solubility index, total sugar level, reducing sugar concentration, antioxidant activity, and gingerol content. The approximate composition of ginger prepared by the MPD method was lower in overall biochemical content than were those of gingers prepared using other methods. Ginger prepared by the MPD method retained the original ginger color. The water absorption and solubility index of ginger prepared by the MPD method (using maltodextrin) were better than those of gingers dried using other methods. The total sugar content did not change noticeably upon processing. The reducing sugar content of ginger prepared by hot-air drying was low. The antioxidant activity of ginger prepared by the MPD method was higher than that of freeze-dried and hot air-dried ginger samples, with values lower than those of BHA (3(2)-t-Butyl-4-hydroxyanisole) and BHT (2,6-Di-tert-butyl-4-methylphenol). The gingerol content of ginger prepared by the freeze-drying method was higher than that of gingers prepared by other methods. However, ginger constituents were present in the dehydration liquid used in the MPD method. The results indicate that both the MPD method (using maltodextrin) and the use of reused dehydration liquid are efficient methods by which ginger can be dried.

• Food Science and Preservation
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• v.11 no.2
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• pp.189-194
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• 2004

This experiment was carried out to compare the quality of semi-dried persimmon according to various drying methods and ripeness degree of persimmons. Most of persimmons were dried naturally there were much opportunities of contamination by impurities, microorganism and discoloration. There were need for developing various drying methods and knowing proper mature degree of persimmons in order to enhance the quality of semi-dried persimmons. Drying time of semi-dried persimmons by hot-air, far infrared ray and dehumid drying could be shorten approximately 11∼12 days, comparing with natural drying. And the loss ratio of natural drying and artifical drying were 7.0% and 0.0%. The moisture content of natural drying and dehumid drying were simillar and the hardness were very low in comparing other drying methods. Average pannel scores in semi-dried persimmons after drying showed that dehumid drying and natural drying were excellent in total prefernce ; 3.9 and 3.4, respectively. Unriped persimmons showed lower moisture content, color values and higher hardness than riped and overriped persimmons. The total preference of riped and overriped fruit were superior than unriped fruit.

• Food Science and Preservation
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• v.17 no.3
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• pp.358-364
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• 2010

Ginger was dried using maltodextrin or recycled dehydration liquid as dehydrating agents, and the quality of dried ginger was compared with that of freeze-dried and hot-air-dried samples in terms of color, moisture content, water activity, dehydration rate, rehydration rate, and sensory properties. Ginger prepared using molecular press dehydration (MPD) retained its original color. The dehydration rate increased when ginger was dried using a dehydrating agent. The rehydration rate was increased in ginger dried using such an agent. Both dehydration and rehydration rates were elevated with increasing concentrations of soluble solids in the dehydration liquid. The sensory qualities of ginger prepared using the MPD method were better than those of freeze-dried and hot air-dried samples. These results indicate that drying of ginger rhizomes using recycled dehydrating liquid is very efficient.

• Food Science and Preservation
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• v.21 no.6
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• pp.838-843
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• 2014

In this study, near-infrared spectroscopy was used to observe the drying non-uniformity of vegetables such as spring onions, onions, and garlic, which are commonly used for seasoning. For the warm-air convection drying method, the vegetables showed drying non-uniformity, which is due to the unevenness of the wind temperature and humidity depending on the height and position of the drying tray. The second derivative spectra between the vegetable samples with different drying degrees were compared. The peak at around 1,390~1,400 nm, which is assigned to weak hydrogen bonds of water, was changed during drying whereas the peak near 1,420 nm, which represents strong hydrogen (H-) bonds of water, was not changed, indicating that water with weak H-bonds evaporates first during drying, and that water with strong H-bonds remains after drying. The hyperspectral NIR imaging technique combined with principal-component analysis made it possible to discriminate the dried vegetables according to their drying degree.

• Food Science and Preservation
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• v.24 no.3
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• pp.361-366
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• 2017

This study investigated quality change of ginseng depending on far-infrared (FIR) drying methods. The ginseng was cut into 2 mm slices and measured moisture content (MC), color, total polyphenol content (TPC), total flavonoid content (TFC) and DPPH radical scavenging activity (DPPH). The color values (L, a, and b) were decreased after far-infrared (FIR) drying. As increase in drying time, color was changed. Considering quality parameters including MC, TPC, TFC, and DPPH, the optimum condition for drying was set at $65^{\circ}C$ for 60 min. Furthermore, we compared color and functional compounds depending on drying process including FIR, freeze-, vacuum, and hot-air drying. The color values of ginseng were decreased when dried using vacuum and hot-air. While the color values of ginseng were increased after freeze drying. Comparison with another drying method, FIR drying presented the highest color difference. FIR and vacuum-dried ginseng indicate higher contents of TPC and TFC than freeze- and hot air-dried ginseng. And hot-air-dried ginseng present the highest DPPH when compared to another drying methods. On the other hand, freeze dried ginseng show the lowest TPC, TFC, and DPPH.

• Food Science and Preservation
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• v.21 no.3
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• pp.341-349
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• 2014

The antioxidative effect and quality characteristics of different drying methods (hot air drying, far-infrared radiation drying, vacuum freeze drying) from Schizandra Chinensis Baillon were investigated. The moisture contents and water activity(Aw) contents each 4.46% and 0.38 values of the vacuum freeze drying were lower than those of other samples. A significant not difference in pH values occurred in all samples (p<0.05). The highest content $^{\circ}brix$ vacuum freeze drying was $6.60^{\circ}Brix$ respectively. The turbidity values of the samples were hot air drying 8.24 T%, far infrared radiation drying 0.32 T%, vacuum freeze drying 71.85 T%. The Hunter's L, a and b values of vacuum freeze drying were higher than those of other samples. The order of the free sugar content was glucose>fructose>sucrose, and that of the total free sugar contents were vacuum freeze drying (6.33 g/100 g) > far infrared drying (5.01 g/100 g) > hot air drying (3.73 g/100g). Antioxidant acitivy (DPPH radical scavenging, ABTS radical scavenging) and total phenol, total flavonoid, and total tannin content was highest in vaccum freeze drying than other different drying methods except nitrite scavenging ability.

• Food Science and Preservation
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• v.23 no.1
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• pp.57-62
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• 2016

The present study was undertaken to determine the changes of physicochemical and antioxidant activity using leaf and root in hot air-dried Allium hookeri (HA) and freeze-dried Allium hookeri (FA). The leaf of HA was higher level of moisture and crude fat compared with those of the leaf of FA. The crude fat content in root of HA was higher than that in FA. However, moisture, crude ash, crude protein and carbohydrate did not show any differences between two different drying methods. The organic acid contents of Allium hookeri root including oxalic acid, citric acid, tartaric acid, malic acid, succinic acid, lactic acid, formic acid, acetic acid showed the differences between hot air-drying and freeze-drying methods. The major minerals were Ca, K and Mg, which were higher level of the leaf of HA compared with those of FA. The leaf of HA showed the highest vitamin C content (801.65 mg/100 g). The content of vitamin E in the leaf of FA was higher than that of HA. The contents of total polyphenol and total flavonoid in the FA leaf were higher than that in HA. The DPPH radical-scavenging activity in leaf of HA (65.73%) was significantly higher than that of FA (57.73%).