• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.201-209
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• 2021

Agarwood (Aquilaria spp) has high economic value. However, essential oil production from agarwood is a time-consuming process. Additionally, agarwood leaves have not been utilized even though they contain various bioactive ingredients. In this study, agarwood leaves were fermented using Lactobacillus plantarum ATCC 8014 with or without Stevia (4, 8, and 12%; v/v). The fermented fluid was mixed with maltodextrin (15%; w/v) and subjected to spray drying (inlet temperature, 120℃; outlet temperature, 65-70℃). The contents of polyphenols, polysaccharides, saponins, and flavonoids and the viability of L. plantarum were determined. Fermentation enhanced the levels of bioactive compounds. The contents of polyphenol (69.19 ± 4.05 mg GAE/g of sample), polysaccharide (20.75 ± 0.98 mg GE/g of sample), saponin (305.23 ± 4.21 mg OAE/g of sample), and flavonoid (7.86 ± 0.72 mg QE/g of sample), and the viability of L. plantarum (8.72 ± 0.17 log CFU/ml) were markedly upregulated in the samples containing Stevia (12%; v/v). This indicated that the supplementation of Stevia during fermentation decreases the fermentation time (9 h), upregulates bioactive compound production in agarwood leaves, enhances microencapsulation during spray drying, and increases the viability of L. plantarum under simulated gastric digestion conditions.

• 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.

• Journal of the Korean Ceramic Society
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• v.33 no.9
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• pp.1057-1063
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• 1996

Y2O3-CeO2-ZrO2 powders were prepared from water-soluble salts using a coprecipitation method. The forming process of oxide and the characteristics of the calcined powders treated in different drying conditions were investigated. The oxidation was occurred at the temperature of around 40$0^{\circ}C$ and the main crystallization of ZrO2 around $600^{\circ}C$. On calcination at $600^{\circ}C$ heating lamp-dried powders consisted of agglomerates of globular morphology with average agglomerate size of 2.27${\mu}{\textrm}{m}$ and specific surface area of 68.3m2/g and spray dried powders contained dense spheric particles with average agglomerate size of 1.35${\mu}{\textrm}{m}$ and specific surface area of 11.0m2/g which exhibited low agglomeration tendency. Removal of the water by a freeze-drying technique produced calcined powders containing flake-like secondary particle structures with wide agglomerate size distri-bution of 0.1-60${\mu}{\textrm}{m}$ and specific surface area of 24.5${\mu}{\textrm}{m}$. The 20 MPa-pressed density (36.8-41.4% T,D) of calcined powders did not nealy depend on drying methods whilst compaction ratio of calcined powders derived from freeze-drying was the highest ( 6.24) among three drying methods. On continuous heating up to 150$0^{\circ}C$ the sinterability of calcined powders derived from heating lamp-drying was superior to those derived from spray-and freeze-drying. The final sintered density of calcined powders was the highest (96% T,D at 150$0^{\circ}C$) in case of heating lamp-drying.

• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.426-434
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• 2022

In this study, the effect of osmotic drying conditions of mangoes on hot air drying was investigated. Four different osmotic agents of 60 Brix, such as S60, SM10, HF80, and SG25, were prepared. Mango slabs were osmotically dried with the agents at a ratio of 1:4 (w/w) for up to 8 hours. SG25 showed the lowest weight reduction and moisture loss during the process. As a result of hot-air drying, all samples showed a high correlation with the Page model (0.9761~0.9997), and the required drying time of all samples that were osmotically dried was reduced compared to the non-osmotically dried group. After hot-air drying, the pH value increased according to the drying temperature. The L, a, and b values and the total polyphenol content also decreased. Through this study, the possibility of osmotic drying was confirmed to increase the efficiency of hot air drying of mangoes, which is expected to contribute to the industrial use of domestic mangoes.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1107-1113
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• 1998

This work was to study the potential use of germinated and microwave-vacuum-dried brown rite as a raw material for enzyme food. Brown rice was soaked in water at $15^{\circ}C$ for 2 days and then germinated at $25^{\circ}C$ for 4 days. The germin ated brown rice was then dried by different drying methods: microwave vacuum drying 1(drying only), microwave vacuum drying 2 $(drying{\rightarrow}crushing{\rightarrow}drying)$, hot air drying, vacuum drying and freeze drying. Each drier except freeze drier was set to maintain the sample temperature to be $60^{\circ}C$. During microwave vacuum drying 1 and 2 the sample reached $60^{\circ}C$ much faster (5 min) and was dried much faster (2 to 3 hrs for microwave vacuum drying 1 and 2 than the other drying methods. The initial drying rate of microwave vacuum drying was ten times faster than that of hot air drying. The microwave vacuum drying produced a dry sample of the highly retained enzymic activity, followed by freeze drying, vacuum drying and hot air drying.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.6
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• pp.479-484
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• 2001

The absorption characteristics of persimmon powder related to different drying methods and various storage temperatures was investigated. The physical properties of persimmon powder by different drying methods displayed the largest amount of porosity in the freeze-dried sample, and the smallest in hot air dried sample. Equilibrium moisture was reached in 6 days. Monolayer moisture contents were predicted to 0.09687~0.19712(freeze drying), 0.07820~0.18617(vacuum drying) and 0.07715~0.18056(hot air drying) g H2O/g solid respectively using the BET equation. BET equation for isothermal absorption curve showed over 0.95 R-square for all dried methods. Monolayer moisture contents were increased as storage temperature was incremented because water molecular movement was more active and there was a greater chance to clash with the absorption surface area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.839-848
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• 2015

This study examined the optimal salting drying method and processing conditions (salt concentration, curing time, dry temperature, and drying time) for preparing salted semi-dried common gray mullet (SSD-CGM) Mugil cephalus based on the moisture content, salinity, and overall acceptance using response surface methodology (RSM). The moisture content, salinity, and overall acceptance of SSD-CGM prepared with different salting methods revealed that dry salting was the optimal salting method for preparing high-quality SSD-CGM. The optimal drying method for preparing high-quality SSD-CGM based on the drying velocity and sensory color was hot air-blast drying. The results of the RSM program indicated that the optimal independent variables ($X_1$, salt concentration; $X_2$, curing time; $X_3$, dry temperature; $X_4$, drying time) based on the dependent variables ($Y_1$, moisture content; $Y_2$, salinity; $Y_3$, overall acceptance) for high-quality SSD-CGM were 5.6% for $X_1$, 2.7 h for $X_2$, $47.0^{\circ}C$ for $X_3$, and 8.5 h for $X_4$ for uncoded values. The predicted values of $Y_1$, $Y_2$, and $Y_3$ for SSD-CGM prepared under optimal conditions were 54.4%, 4.2%, and 6.3, respectively, while the experimental values were $55.2{\pm}1.0%$, $4.1{\pm}0.3%$ and $6.7{\pm}0.8$. The actual and predicted values did not differ.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.4
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• pp.315-326
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• 1996

An experiment was carried out to determine effect of cultivar, drying agent concentration and preservative on the moisture content, temperature and quality changes of fall harvested oat(Avena sativa L.) hay during field curing and storage. The main plots consisted of the cultivar such as 'Foothill' and 'Swan', the subplots consisted of drying agent concentration such as 7Skg/ha(C1), lOSkglha(C2) and control(C0) and the sub-subplots consisted of preservative such as buffered acid(BA), lactic bacteria inoculant(LB) and control(C0). Moisture contents of 'Foothill' and 'Swan' oat cultivar at harvest were 635.5 and 385.4%DW(Dry weight), respectively, but the final moisture contents of the oat cultivars were 117 and 86%DW. The moisture content of cut oat was not affeded by drying agent concentration. Core temperature of baled 'Swan' oat hay was a little higher than that of 'Foothill' and no consistent preservative effect was found. Total nitrogen content of 'Swan' oat hay was 3.08% and that of 'Foothill' oat hay was 3.45%(P<0.05). Drying agent treatment increased total nitrogen content of 'Swan'(P <0.05), but preservative had no effect. Crude fiber content of oat cultivar was increased as the curing progressed(P<0.05) and the difference of crude fiber content of oat cultivar was maintained through the whole curing period. Effect of drying agent concentration on crude fiber content was not found after preservation. Crude fiber content of 'Swan' oat hay was higher than that of 'Foothill' by 1.O% in ADF and 3.1 % in NDF(P<0.05). No preservative effect was found in crude fiber content. According to RFV of oat cultivar at harvest, forage quality of 'Foothill' and 'Swan' was Prime and Grade 1, respectively, but that of both cultivm was above Grade 2 at the final curing day. RFV of the stored 'Foothill' and 'Swan' oat hay was 122 and 114(P<0.05), respectively, and the quality of oat hay was classified as Grade 1 and 2, respectively, according to the forage quality standard assigned by AFGC.

• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.101-109
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• 2015

To extend shelf life of mulberry fruits, usually expensive freeze drying of freezing process is required. In this study an economic to multipurpose agricultural products dryers with mulberry dryer and technique was developed to reduce postharvest processing cost. Fuel and electricity consumption for drying were lowest when drying temperature was $60^{\circ}C$. And various drying conditions (fuel 3 hrs, heat 1 hr, room temperature air velocity 51 hrs) of the developed dryer were analyzed to improve drying performance. Dried mulberry fruits had dark brown color and marketable high quality explain the semi-dried characteristics.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.139-145
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• 2012

Objectives : This study aimed to investigate value differences among Gastrodiae Rhizoma samples(GM, GC, G1, G2 and G3) in various characteristics as well as to provide basic guideline for various processes such as steaming and drying of Gastrodiae Rhizoma. Methods : Gastrodiae Rhizoma were steamed and dried at different temperature and times. They were divided into samples (GM; cultivated, steamed and dried in Muju, GC; cultivated and dried in China, G1; steamed and dried at $55^{\circ}C$ for 60 hours, G2; steamed and dried at $55^{\circ}C$ for 120 hours, G3; steamed and dried at $70^{\circ}C$ for 120 hours) for experiment. They were extracted using water, freeze dried and powdered to analyze gastrodin content, antioxidant activity and sensory evaluation. Results : Proximate composition and the amount of free sugars of Gastrodiae Rhizoma had a little bit differences. Phenolic and flavonoid content of samples were increased by increasing drying temperature and times. Gastrodin content had different values by drying method and G3 was the highest in comparison with others. Increasing drying times led to a increasing in radical and nitrate scavenging activity in samples. Regarding to sensory evaluation, G3 was selected as the best sample according to its highest hedonic score mean (6.11/7) among all samples for appearance, color, flavor, overall acceptability. Conclusions : The results indicated that G3 sample was effective in views of antioxidant activity, gastrodin content and sensory characteristics. Moreover, Gastrodiae Rhizoma cultivated in Korea were investigated with higher antioxidant activity, gastrodin content and sensory characteristics than those cultivated in China.