• Korean Journal of Medicinal Crop Science
• /
• v.6 no.4
• /
• pp.245-250
• /
• 1998

This research was carried out to investigate the effective methods of browning inhibition on Paeonia lactiflra Pall during hot air dehydratin. After drying for 36 hrs without pretreatment and with briquet fumigation moisture contents of Paeonia lactiflora Pall. was 16.0% and 16.2%, respectively, while with acidic solution, sulfite salt solution and blanching it was lower of 13.5, 12.9 and 14.8%, respectively. Using freeze drying moisture content was highest of 18.8%. The Hunter values of dried Paeonia lactiflora Pall., L, a, band ${\triangle} E$ showed that non-treatment had the most browning with 61.60, 1.89, 10.20 and 39.78, respectively, while briquet fumigation and sulfite salt solution were excellent in reducing browning. During freeze drying browning didn't occur. Paeoniflorin content was 2.41 and 2.51 %, respectively, in briquet fumigation and sulfite salt solution and was the highest (2.70%) in freeze drying. The content of $SO_2$, was 0.63% both in briquet fumigation and sulfite salts. It was 0.15% and 0.17% higher than nontreatment and freeze drying. The most effective pretreatment to inhibit browning of Paeonia lactiflora Pall. was soaking in sulfite salt solution $(0.5% NaHSO_4-0.5% Na_2S_2O_3)$ considering many things such as manpower, economical efficiency, drying time, commodity, etc. but safety should be evaluated to treat sulfite salts solution on peony roots.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.3
• /
• pp.234-238
• /
• 1990

The effects of salt concentration immersion time in a salt solution prior to air dehydration and heating of air temperature during dehydration upon the browning reaction and pyruvic acid content of air dried garlics to a 6.5% moisture content(wet basis) were analyzed by a response surface methodology(RSM), Those values were also predicted by using a second degree polynomial regression model. Heating of air temperature was the most significant factor affecting the both browning reaction and pyruvic acid content. Salt concentration had more influence to browning reaction than immersion time whereas immersion time was more impor-tant factor than salt concentration on a retention of pyruvic acid sugested different processing conditions. While the processing conditions to minimize the browning reaction(O.D=0.009) were 0.3% of salt solution 9 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(O.D=0.022) of air dehydration at 5$0^{\circ}C$ Pyruvic acid contents were maximized(174 $\mu$mole/g garlic solid) at the 0.1% of salt solution 3 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(147 $\mu$mole/g garlic solid) of air dehydration at 5$0^{\circ}C$

• Journal of the Korean Wood Science and Technology
• /
• v.29 no.4
• /
• pp.16-24
• /
• 2001

Conventional hot-air oven-drying method takes at least four hours to determine the moisture content of wood sample and this method is not always acceptable to wood industry. In this study samples of six different specifications from Paulownia coreana, Pinus densiflora and Quercus acutissima were dried in domestic microwave oven to their oven dry weights to investigate the possibility of rapid moisture content determination technique using microwave-oven drying method. Continuous heating time, cooling time and intermittent heating time were determined by each species and sample specifications. Temperatures of surface and center of samples were also measured during drying. Oven-drying times were reduced to 1/7~1/10 of conventional hot-air oven-drying method. Therefore microwave heating and drying techniques appear attractive for wood industry as a rapid moisture content determination method.

• Korean Journal of Poultry Science
• /
• v.15 no.1
• /
• pp.45-51
• /
• 1988

This experiment was conducted to determine yolk addition level for manufacturing the seasoned yolk Products. They were Prepared with 0, 10, 20, 40% yolk content in conduction with fish meat faste and spices. Yolk mixture was cooked at $90^{\circ}C$ for 1 hour and then dried with hot air at 5511 for 5 hours. The texture of non-dried seasoned product added with 10% yolk was remarkably increased as compared with any other treatment. For the drying process of seasoned yolk product, the more addition of egg yolk to the mure resulted in a slight difficulties on drying. As yolk level increased in dried seasoned product (egg jerky), moisture and fat content increased whereas protein and total amino acid content decreased. Most of amino acid except leucine, isoleucine and phenylalanine decreased by increasing level of egg ye The Predominant amino acids were glutamic acid, aspartic acid and lysine but only small amount of proline was detected in each treatment. Results of experiment indicated that yolk could be used up 20% level in view of physicochemical and sensory quality in seasoned products.

• Korean Journal of Food Science and Technology
• /
• v.35 no.2
• /
• pp.211-216
• /
• 2003

Absorption characteristics of hot air-. vacuum-, and freeze-dried ginger powder were investigated. Monolayer moisture content as determined by GAB equation was $0.257{\sim}0.540\;H_2O/g$, showing higher significance than BET equation. Absorption enthalpy was calculated based on different drying methods and water activities. Absorption energy decreased with increasing water activity but was not affected by drying method. Isotherm curves showed a typical sigmoid form. Among models applied for predicting equilibrium moisture content, Caurie model was the best fit model for ginger powder, showing the lowest prediction deviation of $1.2{\sim}5.4%$, followed by Henderson then Bradley models. The prediction model equations for the moisture content were established by in(time), water activity, and temperature.

• Korean Journal of Food Science and Technology
• /
• v.11 no.4
• /
• pp.258-263
• /
• 1979

A cylindrical focusing solar food dryer made with aluminum-laminated acryl film was demonstrated for the dehydration of agricultural product and its perfomance was analyzed with respect to the solar energy utilization and its scale-up technology. With one square meter reflector and a 74 cm copper pipe absorber, the heat exchange efficiency between air stream and absorber was 1.39 %. The installation of circular segment-baffle increased 33 % of the efficiency. In dehydration of radish-cut with this drier, 58 % of fuel consumption was saved. The relationship between reflector area and heat energy utilization was established for the scale-up purpose.

• Korean Journal of Medicinal Crop Science
• /
• v.4 no.4
• /
• pp.283-287
• /
• 1996

As a part of studies on the quality control for drying methods in Lycii Fructus. Dried Lycii Fructus were obtained from several treatments to examine the control of the extracts and its physical properties, and also to analyze the inorganic elements and proximate compositions. The results were summerized as follows; the changes of solid matter contents dried at $50^{\circ}C\;for\;4\;hrs\;and\;60^{\circ}C$ for 28 hrs were highest. The changes of Hunter values were 66 in lightness, 5.0 in redness and 51.3 in yellowness, respectively in treatment No. 1. And also the viscosity of treatment No. 1. was some high compared to the other treatment. The desirable drying temperature were at $50^{\circ}C$ for 2hrs in initial and at $60^{\circ}C$ for 24hrs in final temperature and it was the best conditions as a quality, economics and chemical compositions of Lycii Fructus.

• Korean Journal of Food Science and Technology
• /
• v.25 no.5
• /
• pp.421-425
• /
• 1993

Hololeion maximowiczii root was analyzed for proximate composition, free sugar, fatty acids of crude lipid, amino acids and minerals after freeze dried (FD), hot air dried (HAD) and hot air dried after blanched (HADB), respectively. Proximate composition was little different among drying methods. Free sugar was abundant in order of sucrose $(28{\sim}29mg/g\;dw)$, fructose $(0.8{\sim}3mg/g\;dw)$, glucose and xylose (trace). Fructose was decreased in HADB. In fatty acid composition of crude lipids, linoleic acid was highest $(55{\sim}59%)$ and then palmitic and linolenic acid in abundance. These three fatty acids made $88{\sim}90%$ of total lipid, Low molecular fatty acids showed decreasing tendancy in HAD and HADB. Amino acid composition of hydrolyzed sample showed abundancy in order of arginine $(34{\sim}42mg/g)$, lysine, glutamic acid, glycine, aspartic acid, valine and histidine, while that of free amino acids was arginine, histidine, lysine, aspartic acid, serine, glutamic acid, isoleucine. Glycine and glutamic acid in hydrolyzed sample showed slight decreasing tendency in HADB. Mineral content was abundance in order of Ca $(1927{\sim}2379\;ppm),\;K\;(1159{\sim}1259ppm)$ and $Mg(760{\sim}777\;ppm)$. No difference was found in drying methods.

• Korean journal of food and cookery science
• /
• v.13 no.4
• /
• pp.422-426
• /
• 1997

Fresh broccoli is known to have the highest content of sulforaphane (S-methylsulfinylbutyl isothiocyanate) among all vegetables. Since isothiocyanates are formed from myrosinase-catalyzed hydrolysis of glucosinolates during tissue destruction of broccoli, the formation of sulforaphane in the extract of broccoli was examined under various processing conditions. The amount of sulforaphane in processed broccoli was measured using GC/MS analysis. Among fresh, dried, and boiled broccoli fresh broccoli exhibited the highest content of sulforaphane. Sulforaphane was maximally produced from the homogenate in 0.1 M phosphate buffer containing 1 mM Vitamin C stored at room temperature for 1 hr. In boiled broccoli, the amount of sulforaphane decreased as the boiling time increased, and reached to 10% of control after 30 min boiling. The amount of sulforaphane was decreased remarkably in dried broccoli in which freeze-dried and heat-dried broccoli had about 50% and 30％ of fresh ones, respectively.

• Korean Journal of Medicinal Crop Science
• /
• v.7 no.3
• /
• pp.172-176
• /
• 1999

The saponins are considered the main effective components in Platycodon grandiflorum (Jacq.) A. DC.. In order to obtain the basic information for producing the high quality medicinal plant and processing, the crude saponin contents were analyzed with platycodi radix, the root of Platycodon grandiflorum by different cultivating years, parts, harvesting times and drying methods. The crude saponin contents were decreased by increasing cultivating years. The crude saponin contents were 2.74% in tail of root and 1.65 % in head of root, respectively. Besides, the contents of the crude saponin in cortex were 1.8 times more than that in core of root. The crude saponin contents in different harvesting times were 2.82% and 2.74% at March 10 and December 10, showing higher than that being harvested at June 10 and September 10. The crude saponin contents among drying methods were not significantly different at 5% level DMRT, but the hot air drying after steam showed the least crude saponin.