• Korean Journal of Food Science and Technology
• /
• v.51 no.6
• /
• pp.551-557
• /
• 2019

The purpose of this study was to investigate the changes of flavor and taste characteristics of black pepper treated with three different nonthermal sterilization methods, which are intense pulsed light (IPL), ultraviolet (UV), and cold plasma (CP). Also, the sensorial and instrumental evaluation of black pepper before and after nonthermal treatments were analyzed. As a result of color value, UV and CP treatments did not show chromacity difference (ΔE), but IPL treatment showed a significant difference of 6.58. Piperine contents of sample before nonthermal treatments was 10.7±0.53 mg/g and the piperine contents of all samples decreased after nonthermal treatments. The result of the electronic nose analysis were divided into two groups before and after nonthermal treatments, and divided into three group by principle component analysis. According to the intensity test, after nonthermal treatments, all sample had low flavor and taste, and the intensity was in the order of IPL, CP, and UV. In thirteen sensory attribute languages developed through quantitiative descriptive analysis (QDA), the intensity value of the samples were low after nonthermal treatments.

• Food Science and Preservation
• /
• v.17 no.2
• /
• pp.230-235
• /
• 2010

We investigated the physicochemical quality characteristics of apple juice upon sterilization using hot water, and under various storage conditions. None of sugar content, acidity, or pH differed significantly among various sterilization conditions but chromaticity was considerably reduced in sterilized juice compared with control material. The chromaticity of non-sterilized juice decreased significantly after sterilization compared with material supplemented with vitamin C (0.1%, w/v). Fungi, yeast, and aerobic bacteria were detected in juice sterilized at $65^{\circ}C$ for 10 or 20 min, but no microorganisms were observed in juice sterilized by other procedures. Vitamin C content affected sterilization temperature to a greater extent than sterilization time. When juice was stored at $4^{\circ}C$ or $37^{\circ}C$ for 3 weeks after application of different sterilization conditions, almost no change in acidity, sugar content, or pH was observed, regardless of sterilization mode or storage period. However, chromaticity decreased with longer storage. Vitamin C levels were reduced by higher sterilization temperatures. However, longer storage periods had the greatest effect on reduction of vitamin C levels, which tended toward lower values regardless of differences in sterilization and storage conditions. In sensory evaluation tests, all of taste, color, and overall preference were highest for juice sterilized at $75^{\circ}C$ for 20 min. The ASC value was low at a storage temperature of $4^{\circ}C$ and at high sterilization temperatures, and a long storage period was associated with a greater ASC value. Thus, the quality of apple juice was excellent when juice was hot water-sterilized, with additional vitamin C, at $75^{\circ}C$ for 20 min, followed by storage at $4^{\circ}C$.

• Applied Chemistry for Engineering
• /
• v.22 no.3
• /
• pp.261-265
• /
• 2011

The sterilization effects of atmospheric pressure plasma with the mixture of argon and oxygen were analyzed. The plasma reactor with the shape of dielectric barrier discharge produced the uniform distribution of glow discharge and generated ozone gas effectively according to the various process parameters. The sterilization for E. coli was affected by power, oxygen ratio in the mixture gas, treatment time and distance between reactor and sample. The concentration of ozone was a major source for the sterilization of E. coli, which was enhanced by the increase of power and oxygen ratio. In this study, the effect of atmospheric pressure plasma treatment for the sterilization was confirmed and its result can deliver the atmospheric pressure plasma treatment as the novel sterilization method instead of conventional methods.

• Asian Journal of Turfgrass Science
• /
• v.26 no.2
• /
• pp.102-109
• /
• 2012

Commercial formulation of fungicides was studied in the golf course for evaluation against Typhula incarnata causal agents of gray snow mold. Efficacies of fungicides application, fungicide mixture, fungicides applied method (irrigation and spray) and fungicides applied time (early fall and late fall) were evaluated for their influence on the chemical control of gray snow mold of turfgrass during the winter season in Yongpyeong golf course, Korea. Unsprayed control has significantly more disease severity than three fungicides (azoxystrobin, propiconazole, and tebuconazole) were applied to field plots. Effect of three fungicides was over 80% with control value for controlling gray snow mold on Kentucky bluegrass and creeping bentgrass species. Effect of fungicide mixture with different family groups had an over 93% control value of gray snow mold on Kentucky bluegrass species. It was not significantly difference in fungicidal effect according to applied method (irrigation and spray) with azoxystrobin on Kentucky bluegrass and creeping bentrasss species. Effect of fungicides applied time was a significantly difference on disease control by tebconazole early fall spray.

• Applied Biological Chemistry
• /
• v.35 no.4
• /
• pp.294-299
• /
• 1992

In order to examine the effect of $TiO_2$ on photosterilization of microorganism. Proper content of $TiO_2$, illumination time, wave length specificity and cell concentration were investigated for photosterilization of E. coli, B. subtilis and S. cerevisiae. The amount of $TiO_2$ for photosterilization of E. coli was effective in the range of $5{\sim}20\;mg%$. The sterilization time was reduced when the low wave length below 400 nth was not cut off by glass, but the catarizing effect of $TiO_2$ was similar to overall wave length. The photosterilization effects by $TiO_2$ addition was recognized among S. cerevisiae, E. coli and B. subtilis in that order. The photosterilization time of S. cerevisiae was considerably reduced at $10^4/ml$ cell concentration compared to $10^5/ml$.

• Korean Journal of Food Science and Technology
• /
• v.47 no.4
• /
• pp.474-479
• /
• 2015

In this study, five different Gochujang (a traditional Korean sauce prepared using fermented red pepper paste) sauces were heated at $100^{\circ}C$ for 5 min using a continuous ohmic heating system. Ohmic heating yielded greater reduction in microbial counts (90-95% reduction) than did conventional heating (65-75% reduction). The sterilization effect of the continuous ohmic heater increased with increasing sample flow rate and decreasing Reynolds number inside the pipe. Low-viscosity samples had higher electrical conductivity and were better suited for ohmic heating than were high-viscosity samples. The color and texture were also satisfactorily maintained after ohmic heating. Compared with conventional heating, ohmic heating provided rapid and uniform heating, which is more suitable for aseptic thermal processing of viscous foods.

• Korean journal of food and cookery science
• /
• v.19 no.3
• /
• pp.396-402
• /
• 2003

The aim of this study was to investigate the quality changes of retort pouched seasoned-conger eel products during a 60 day of storage at 4, 15 and -20$^{\circ}C$. The seasoned-conger eel products was sterilized at either 100 or 121$^{\circ}C$ for 90min., and then vacuum packed in plastic film bags. When comparing their duality before and after sterilization, the pH and VBN of all the products slightly decreased, while the TBA values slightly increased after sterilization. The color value, b, of the product decreased after sterilization, while the L value rarely changed. During storage the pH and VBN of all the products were little changed at the storage temperatures of 15 and -20$^{\circ}C$. The TBA values increased after 30 and 60 days at 15$^{\circ}C$, and at 4 and -20$^{\circ}C$, respectively. As for color difference during storage, the L and a values were little changed during storage, while the b value increased. In conclusion, the quality of the retort pouched seasoned-conger eel products remained good during the 60 day storage period when chilled and frozen after sterilization, and could be consumed as an instant food, keeping an appropriate content and soft texture.

• The Korean Journal of Pesticide Science
• /
• v.19 no.3
• /
• pp.323-328
• /
• 2015

Control efficacy was investigated with fungicides as 3 copper compound, 3 antibiotic fungicides and one fungicide containing to quinolone against the growth of Ralstonia solanacearum on NA medium and the disease occurrence on pepper seedlings. Among 7 fungicides, oxytetracycline was shown the highest activity against a growth of the pathogen in the agar diffusion method, but validamycin showed no activity against the pathogen. With $1000{\mu}g\;mL^{-1}$ of each copper fungicide as copper hydroxide, copper oxychloride+ dithianone and copper sulfate, 2.2, 1.3 and 1.5 mm in size of clear zone only could be found, respectively. In pepper seedling test, oxytetracycline showed a perfect activity in all treatments 7 days after inoculation. However, its activity was decreased from $500{\mu}g\;mL^{-1}$ of treatment over the time. Copper fungicides showed the control efficacy lower than antibiotic fungicides except for validamycin. Based on the results, it was suggested that it would be better to use antibiotic fungicides than copper fungicides to control pepper bacterial wilt in the fields.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.1
• /
• pp.148-152
• /
• 2013

An ultraviolet (UV) sterilization system was developed to decrease the number of microorganisms in filtered Acer mono sap (FAS). The Acer mono sap (AS) was passed through 18 strips of PTA fluoroplastic tubing with 30 UV lamps (total 1,170 W). During passage, the AS was effectively exposed to the UV rays. The total bacteria, coliform group and fungi were sterilized at a flow rate ranging from 852 to 1,358 mL/min and a UV power higher than 156 W. Although the sensory score of the UV-sterilized AS was significantly lower than that of the untreated AS, the sensory score was better under the condition of 390 W and 852~1,358 mL/min than under the other conditions examined. ANOVA did not reveal a significant difference in pH, total acidity, sugar content and color characteristic under all conditions tested (p<0.05). Considering the overall attributes of the AS quality, the optimum sterilization condition was determined to be 390 W and 852~1,358 mL/min.

• Korean Journal of Food Science and Technology
• /
• v.43 no.2
• /
• pp.156-160
• /
• 2011

A tray type-infrared (IR) pasteurization system was developed for decreasing microorganisms in red pepper powder (RPP). The RPP was passed through a tray by a vibrating mode under the 4 IR lamps (total 8000 W) and by circulating water under the tray. Fungi was pasteurized by applying power higher than 2000 W to the RPP. The decrease in viable cell numbers of bacteria, however, was not observed under the same conditions. Conveying speed of RPP was optimized to 106-164 g/min on the basis of microbial reduction and retaining of moisture content of RPP. The water content of 32 mesh-RPP decreased rapidly after pasteurization. However, fungi in both RPPs could be sterilized regardless of particle sizes. The repetition of IR pasteurization was not favourable due to severe decrease of water content in RPP. The IR pasteurization of RPP did not cause significant difference in the capsaicinoid contents, ASTA colour value, and L, a, and b values under all investigated conditions.