• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.2
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• pp.121-126
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• 1990

Internal mass transfer during osmotic concentration of apples in sugar solutions was exami-ned as a function of concentration temperature and immersion time of those solutions using moisture loss sugar gain molality and rate parameter. Influence of osmotic concentration processes on browning reaction was also evaluated compared to control In creasin the concen-tration and temperature of sugar solutions increased moistrue loss sugar gain molality and rate parameter. Water loss was rapid early in the process and then levelled off, The same phenomena were occurred on sugar gain only in higher concentration(60$^{\circ}$ brix). IN lower concentration (30$^{\circ}$brix) sugar gain was gradually increased during whole process. Moisture loss during osmotic concentration using a sugar solution(60$^{\circ}$ brix 6$0^{\circ}C$) with 180min immer-sion time was 45.79% Effect of osmotic concentration befor air dried to 4% M.C(wet basis) on browning reaction was significant. Minimum browning reaction during air drying was carried out using a pretreatment such as osmotic concentration in sugar solution(60$^{\circ}$brix 45$^{\circ}C$) with 150min immersion time(O.D=0.01) compared to control(O.D=0.17)

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.660-664
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• 2014

This study aimed to investigate the effects of various soft steam treatments, namely, forced convection-boiler, forced convection-fan, and natural convection, on the pretreatment characteristics of potatoes. In this study, potatoes were exposed to various cooking conditions, including steaming method, treatment time (0-60 min), and temperature (60, 70, $80^{\circ}C$). Then, changes in temperature, cook value, ascorbic acid content, moisture content, and weight loss in the fresh and steam-treated samples were measured and evaluated. The results clearly showed that natural convective steaming was superior to other treatments in terms of heating characteristics, cook value (FC-b: $46.4{\pm}1.7$, FC-f: $21.8{\pm}1.1$, NC: $52.1{\pm}1.9min$ at $80^{\circ}C$), ascorbic acid content (FC-b: $36.5{\pm}2.7$, FC-f: $28.5{\pm}2.9$, NC: $48.2%{\pm}2.5%$ at $80^{\circ}C$), moisture retention (FCb: $74.6{\pm}0.8$, FC-f: $71.5{\pm}0.5$, NC: $77.6%{\pm}0.4%$ for 60 min at $80^{\circ}C$), and weight loss (FC-b: $13.9{\pm}0.8$, FC-f: $15.6{\pm}0.6$, NC: $10.6%{\pm}0.7%$ for 60 min at $80^{\circ}C$) for thermally processed potatoes.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.719-725
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• 2009

Heterocyclic aromatic amines (HCAs) are potent mutagens and possible human carcinogens that are formed during the heating of protein-rich foods. The effects of preheating treatment of beef patties using a microwave prior to frying at $220^{\circ}C$ for 10 min on each side on the reduction of HCAs (amino-carbolines and amino-imidazo-azaarenes) were evaluated. The amount of HCAs was then evaluated by solid-phase extraction and high pressure liquid chromatography (HPLC) analysis. The beef patties were treated by microwaving for various times (0, 1, 1.5, 2, or 3 min) before pan-frying. The results revealed the presence of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b] indole (Trp-P-1), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), 9H-pyrido[3,4-b]indole (Norharman), 1-methyl-9H-pyrido[3,4-b]indole (Harman), 2-amino-9H-pyrido[2,3-b] indole ($A{\alpha}C$), 2-amino-3,8 dimethylimidazo[4,5-f]-quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP) in all samples. However, microwave pretreatment for 1 min inhibited the formation of these HCAs by up to 90% when compared to the control.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.172-178
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• 2018

The sterilization rates were investigated to develop effective pretreatment methods of garlic and ginger using antimicrobial agents and blanching. Antibacterial components in chopped garlic and ginger, such as allicin, ginger, and shogaol, exhibited an antibacterial effect that reduced bacteria by a factor of $10^1(CFU/g)$. The total number of bacteria in garlic and ginger was decreased by $10^1(CFU/g)$ after individually soaking in 1% (w/w) citric acid, calcium oxide and 200 ppm sodium hypochlorite solution for 1 h, respectively. When chopped garlic and ginger were immersed in 1% (w/w) calcium oxide solution for 1 h, the bactericidal effect was increased by $10^4-fold$. Total cells with thermoduric bacteria exhibited a $10^3-10^4-fold$ reduction after heating for 30-40 s at $90-95^{\circ}C$. The combination of soaking in 200 ppm sodium hypochlorite solution and blanching at $95^{\circ}C$, 40 s showed $10^1-fold$ decrease in total number of cells compared to blanching in whole ginger.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.707-714
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• 2005

Ingredient ratio for making nabak kimchi and the manufacturing method were standardized from the available literatures. Fermentation properties and $CO_2$ production of the nabak kimchi were investigated during the fermentation at $5^{\circ}C,\;10^{\circ}C,\;and\;20^{\circ}C$. Standardized ingredients ratio of nabak kimchi that added 100 mL of water was as follows: 45.0 g baechu cabbage, 26.9 g radish, 1.9 g green onion, 1.0 g red pepper, 1.2 g crushed garlic, 0.9 g crushed ginger, 0.7 g red pepper powder. The standardized manufacturing method of nabak kimchi was as follows: washing ingredients, cutting radish and baechu cabbage $(2.5\times2.5\times0.5\;cm)$, salting for 20 min, washing and draining, pretreatment of ingredients, dissolving red pepper powder in water, blending, mixing, and adding the water to the mixed ingredients. Fermentations at $5^{\circ}C$ for 8 days, at $10^{\circ}C$ for 3 days, and at $20^{\circ}C$ for 1 day led to the acidity levels of $0.21\%,\;0.20\%,\;and\;0.31\%$, respectively. From the relationships between optimally ripened pH and acidity, nabak kimchi showed lower acidity of $0.20\~0.25\%$ with pH $4.2\~4.5.$ Like other kinds of kimchi, the Levels of Leuconostoc sp. were high specially at later stage of fermentation at low temperature $(5^{\circ}C)$. However, the levels of Lactobacillus sp. were low at $5^{\circ}C$. Nabak kimchi produced high levels of $CO_2$ in the initial fermentation period and followed by rapid decrease of $CO_2$ production with the fermentation. From the relationships between pH and $CO_2$ content, the highest $CO_2$ contents were found pH $4.0\~4.4$, 3.8 and 3.4 at $5^{\circ}C,\;10^{\circ}C$, and $20^{\circ}C$, respectively. This fact indicated that fermentation at $5^{\circ}C$ has the highest $CO_2$ content at optimally ripened pH of 4.3 and the fermentation at lower temperature such as $5^{\circ}C$ could extend the eatable time of nabak kimchi.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.68-75
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• 2001

Reasonable seedling emergence is a prerequisite for successful crop cultivation especially in medicinal crops. The study was carried out to model the pretreatment or seed treatment of Codonopsis lanceolata seeds by evaluating the treatment effects of priming, $GA_3$, drying and water imbibition after drying on their germination and then their successive seed treatment on the basis of its seedling emergence. The priming using $Ca(NO_3)_2$ and $GA_3$ treatment under their different concentrations and light quality illuminated for 12 hours a day were separately done and the two best results from priming and $GA_3$ treatments were compared to determine the better one. The drying of imbibed seeds using the above best result and water imbibition of the dried seeds were successively done to measure the rates of germination and emergence. On the greatest germination rate of the first two individual treatments, priming was obtained at $Ca(NO_3)_2$ 150 mM under blue, red light or darkness for 2 days but $GA_3$ was done at 0.1 mM under blue light imposed for 3 days. However, the result of the latter $GA_3$ treatment was better than that of priming. $GA_3$ treated seeds were best desiccated under $35^{\circ}C$ and 4 hour red light illumination. A day water imbibition immediately before sowing increased the germination rate of seeds dried after $GA_3$ treatment. Seedling emergence tested after all 3 successive treatments, $GA_3$, drying and water imbibition before sowing was greater than the two others, only $GA_3$ treatment and the combination of $GA_3$ and drying, meaning that its pretreatment of seeds or seed treatment must follow the successive procedure of the above 3 ones.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.5
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• pp.571-580
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• 2008

The influence of bacterial stress on anaerobic hydrogen-producing microorganisms was investigated in batch tests using serum bottles. Several physical and chemical stresses (i.e., heating, adding methane producing inhibitor and chemical acidification) were adapted as a pretreament of the seed sludge. In this experiment, the cultivation temperature were set at mesophilic ($35^{\circ}C$) and thermophilic conditions ($55^{\circ}C$) with adjusting pH at 5, 6, and 7 when using the mixture of food waste and activated sludge as a substrate. In conjunction with the pretreatment, hydrogen production was significantly enhanced as compared with that from untreated sludge. However, less biogas (hydrogen and methane) was produced without the pH control, resulted from the decrease of pH to below 4, mainly due to the formation of VFAs. Hydrogen and carbon dioxide gas were analyzed as main components of the biogas while methane not detected. With an application of chemical acidification, the highest hydrogen production value of 248 ml/l/day achieved at pH 7 and $35^{\circ}C$. In addition, more hydrogen gas produced when the ratio of butyric/acetic acid ratio increased. The optimum pH and temperature for hydrogen production were found to be 7 and $35^{\circ}C$, respectively.

• Korean Journal of Metals and Materials
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• v.48 no.3
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• pp.225-234
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• 2010

Salt bath nitriding, which has been developed recently by domestic company, is an emerging ecofriendly surface treatment. The salt bath nitriding is accompanied by the electrolysis process in the pretreatment step, and this whole processis called Pseudo-Electrolysised Salt bath Nitriding (PESN). The PESN creates only $NH_3$ and non-toxic salts without harmful $CN^{-}$ or toxic gas such as that found in previous salt bath nitriding. In general, ion nitriding and gas nitriding create high hardness and a strong brittle white layer on the surface. However, the PESN shows a thin white and gray layer. The PESN was applied to the defense material, 3%Cr-Mo-V steel, to study the surface characteristics at $480^{\circ}C$, $530^{\circ}C$, and $580^{\circ}C$ for 4 hrs, 20 hrs, 40 hrs, and 60 hrs of nitriding time condition. As a result, the best nitriding layer was found at $530^{\circ}C$ for 40 hrs. If we improve corrosion resistance and nitriding layer depth, the PESN will be able to be applied to the defense industry parts.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.682-689
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• 2015

A two-step process was investigated for pretreatment and fractionation of rice straw. The two-step fractionation process involves first, soaking rice straw in aqueous ammonia (SAA) in a batch reactor to recover lignin-rich hydrolysate. This is followed by a second-step treatment in a fixed-bed flow-through column reactor to recover xylo-oligomer-rich hydrolysate. The remaining glucan-rich solid cake is then subjected to an enzymatic process. In the first variant, SAA treatment in the first step dissolves lignin at moderate temperature (60 and $80^{\circ}C$), while in the second step, hot-water treatment is used for xylan removal at higher temperatures ($150{\sim}210^{\circ}C$). Under optimal conditions ($190^{\circ}C$ reaction temperature, 30 min reaction time, 5.0 ml/min flow rate, and 2.3 MPa reaction pressure), the SAA-hot-water fractionation removed 79.2% of the lignin and 63.4% of the xylan. In the second variant, SAA was followed by treatment with dilute sulfuric acid. With this process, optimal treatment conditions for effective fractionation of xylo-oligomer were found to be $80^{\circ}C$, 12 h reaction time, solid-to-liquid ratio of 1:12 in the first step; and 5.0 ml $H_2SO_4/min$, $170^{\circ}C$, and 2.3 MPa in the second step. After this two-step fractionation process, 85.4% lignin removal and 78.9% xylan removal (26.8% xylan recovery) were achieved. Use of the optimized second variant of the two-step fractionation process (SAA and $H_2SO_4$) resulted in enhanced enzymatic digestibility of the treated solid (99% glucan digestibility) with 15 FPU (filter paper unit) of CTec2 (cellulase)/g-glucan of enzyme loading, which was higher than 92% in the two-step fractionation process (SAA and hot-water).

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.179.1-179.1
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• 2011

Pretreatment of cellulosic biomass is necessary before enzymatic saccharification and fermentation. The objective of this study was to evaluate the effect of combined aqueous ammonia-dilute sulfuric acid treatment on cellulosic biomass. Miscanthus was pretreated using aqueous ammonia and dilute sulfuric acid solution under high temperature and pressure conditions to be converted into bioethanol. Aqueous ammonia treatment was performed with 15 %(w/w) ammonia solution at $150^{\circ}C$ of reaction temperature and 20 minutes of reaction time. And then, dilute sulfuric acid treatment was performed with 1.0 %(w/w) sulfuric acid solution at $150^{\circ}C$ of reaction temperature and 10 minutes of reaction time. The compositional variations of this combined aqueous ammonia-dilute sulfuric acid treatment resulted in 68.0 % of cellulose recovery and 95.7 % of hemicellulose, 81.3 % of lignin, 89.1 % of ash removal respectively. The enzymatic digestibility of 90.5 % was recorded in the combined pretreated Miscanthus sample and it was 14.7 times higher than the untreated sample. The ethanol yield in the Simultaneous Saccharification and Fermentation was 90.4 % of maximum theoretical yield based on cellulose content of the combined pretreated sample and it was about 98 % compared to the ${\alpha}$-cellulose ethanol yield.