• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.368-374
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• 2020

BACKGROUND: The residual analysis of polar pesticides has remained a challenge. It is even more difficult to simultaneously analyze multiple polar pesticides. Diquat, paraquat, and chlormequat are typical examples of highly polar pesticides. The existing methods for the analysis of diquat, paraquat and chlormequat are complex and time consuming. Therefore, a simple, quick and effective method was developed in the represent study for simultaneous analysis of diquat, paraquat and chlormequat in animal products, meat and fat using UPLC-MS/MS. METHODS AND RESULTS: Sample extraction was carried out using acidified acetonitrile and water and re- extracted with acidified acetonitrile and combine the extracts followed by centrifugation. The extract was then cleaned up with a HLB cartridge after reconstitution with acidic acetonitrile and water. The method was validated in quintuplicate at three different concentrations. The limits of detection (LOD) and quantification (LOQ) were 0.0015 and 0.005 mg/L, respectively. Matrix suppression effect was observed for all of the analytes. A seven point matrix matched calibration curve was constructed for each of the compound resulted excellent linearity with determination coefficients (R2) ≥ 0.991. Accuracy and precision of the method was calculated from the recovery and repeatability and ranged from 62.4 to 119.7% with relative standard deviation less than 18.8%. CONCLUSION: The recovery and repeatability of the developed method were in the acceptable range according to the Codex Alimentarius guideline. The developed method can be applied for the routine monitoring of diquat, paraquat, and chlormequat in animal products, meat and fat.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.49-56
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• 2018

A novel printable time-temperature integrator (TTI) composed of a natural coloring matter, anthocyanidin, was developed. The anthocyanin was biochemically modified to change in color over week scale, compared to the original anthocyanin over month scale change. The anthocyanin extracted from strawberry was converted to its aglycone, anthocyanidin, by the treatment with ${\beta}-glucosidase$. The print paste was composed of the freeze-dried powder of anthocyanidin, pullulan, glycerol and distilled water, which was screen-printed. The TTI performance were examined in terms of kinetics and temperature dependency. The activation energy of anthocyanidin TTI was 86.92 kJ/mol. Compared with the activation energy of foods, the applicable food groups were found. Applicable food groups were chilled meat products and fish. The major benefits of the TTI were the printability to be practical in use and the eco-friendliness with the natural pigment.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.313-319
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• 2017

Strawberries are one of the main commodities in Korea and have been exported over 30 million dollar. And the safety has recently become an important issue in the agro-trade, pesticide residue is most important matter of safe agricultural products. As strawberries can be cultivated using elevated production system, so it is possible to use the drenching. When spraying the pesticides, the use of drenching can be lower amount of residual than using foliar treatment. In this study, time sequential residual amount of pesticides were compared between drenching and foliar application in strawberries. Pesticides were treated with the standard and double dosage and samples were collected at 0, 3, 6, 9, 13, 16 and 21 day and analyzed by LC and LC-MS/MS after liquid-liquid extraction and QuEChERS. Two pesticides were detected less than 1 mg/kg in all samples for drenching treatment. Carbendazim residues in drenching treatment were 5 to 25 times lower than foliar application. And azoxystrobin was not detected in strawberries of drenching treatment.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.14-25
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• 2018

Chemical compositions, trypsin inhibitory activity, and gelling properties of albumen from duck egg during salting of 30 days were studied. As the salting time increased, moisture content decreased, the salt content and surface hydrophobicity increased (p<0.05). Trypsin inhibitory activity and specific activity were continuously decreased throughout the salting time of 30 days (p<0.05). This coincided with the decrease in band intensity of inhibitor with molecular weight of 44 kDa as examined by inhibitory activity staining. Nevertheless, no differences in protein patterns were observed in albumen during the salting of 30 days. Based on texture profile analysis, hardness, springiness, gumminess, chewiness, and resilience of albumen gel decreased with increasing salting time. Conversely, salted albumen gels exhibited higher cohesiveness and adhesiveness, compared to those of fresh albumen. Scanning electron microscopic study revealed that gel of salted albumen showed the larger voids and less compactness. In general, salting lowered trypsin inhibitory activity and gelling property of albumen from duck egg to some extent. Nevertheless, the salted albumen with the remaining inhibitor could be an alternative additive for surimi or other meat products to prevent proteolysis.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.308-314
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• 2012

In order to monitor the residual pesticides in environment friendly agricultural commodities, fruits and fruiting vegetables. Twenty-five agricultural commodities were collected twice in May and August 2011 from nine environment friendly agricultural commodities-selling supermarkets and retail stores located in eight major cities in Korea. The number of each agricultural commodity collected, 555 samples in total, was 152 organic agricultural products, 202 pesticide-free agricultural products and 201 low-pesticide agricultural products. Pesticide residues in samples were analyzed by multiresidue method for 245 pesticides using a GC-ECD/NPD and an HPLC-DAD/FLD and the peaks suspected as pesticides were identified with a GC/MSD. As a result of pesticide residue analysis, three pesticides, bifenthrin, EPN and chlorpyrifos, were detected from four samples including apple, representing a detection rate of 0.72%. The residue levels of the four pesticide-detected samples were less than their maximum residue limits (MRLs) but one pesticide EPN detected from pear exceeded its legible criterion of one twentieth MRL. Estimated daily intakes of the pesticides detected from fruits and fruiting vegetables were less than 0.76% of their maximum permissible intake.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.11-17
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• 2019

Strawberries are one of the main commodities in Korea and have been exported over 40 million dollar. Because the strawberry cultivation using hydroponics has increased, treatment of pesticide by drenching draw interest recently. However, detailed researches for drenching treatment of pesticide are limited, which results in difficulties in proper pesticide applications in agricultural fields. To activate use of drenching and improve safety in agricultural products, In this study, time-dependent residual characteristic of pesticides were compared with between different applications of pesticides in strawberries. The characteristics of azoxystrobin, prochloraz and thiamethoxam were investigated with drenching treatment at different applications: the time of treatment, concentration etc. at hydroponic cultivation for 40 days. Azoxystrobin and prochloraz were not detected at 14 day after application. Thiamethoxam was detected from 0.02 to 0.85 mg/kg. Crop uptake of pesticides was strongly affected with octanol-water partition coefficient and solubility in water. Residual amount in crops are highly dependent on the concentration of active ingredient of pesticides.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.4
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• pp.451-460
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• 2013

The purpose of this study is to investigate the volatile compounds of Korean traditional gochujang from various districts. The volatiles from each traditional gochujang are being extracted by simultaneous steam distillation extraction (SDE), and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Twenty compounds are identified as major volatile components which include 8 esters, 4 alcohols and 4 acids. The most traditional gochujang possesses more volatile components rather than commercial gochujang products. Most acids come from fatty acids and the alcohols derive from the oxidative degradation of linolenic acid. The most abundant volatile compounds for both traditional and commercial gochujang include 10 compounds such as 2-methyl-1-propanol, hexanal, 2-methyl-1-butanol, octanoic acid ethyl ester, as well as the various type of acids and esters. They represent most of the total GC peak areas, respectively. From the results, the characteristics of the flavors for traditional gochujang from each district are not clear but have shown various components than the commercial products.

• Journal of the FoodService Safety
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• v.2 no.2
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• pp.78-83
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• 2021

According to the report of the Korea Agro-Fisheries and Food Trade Corporation (2019), the size of the HMR food market in 2019 exceeded 4 trillion won. On the other hand, the consumption of agricultural products continued to decrease. As reported by Woo (2020) who analyzed consumer panel survey data, when the 2010 agricultural product purchase index was 100, the crop purchase index in 2019 was 72 and the vegetable and special crop purchase index was 69. Therefore, the Rural Development Administration promoted the research projects to develop the technologies for producing stably raw materials of HMR and for optimizing local foods as HMR ingredients. Researches on the development of HMR using local agricultural products has been being promoted in Cheonan, Chungju, and Jeju in 2020. In the case of Jeju, it has been prepared and realized the B2B commercialization of Jeju agricultural products in connection with the convenience store ingredients supplier in the province. In the case of Cheonan, development of HMR foods like as Sundae, dumpling, sausage, and Tteokgalbi using willd chive, cherry tomatoes, shiitake mushroom, fortified perilla, and licopene fortified watermelon has been being promoted. Lastly, in the case of Chungju, a diverse HMR foods have been developed using beans, centella asatica, Japanese lady bell, apples and peaches such as blended juices, frozen boiled rice, and tofu kit. In the future, in connection with the regional specialized crop cultivation project promoted by the Rural Development Administration, we intend to support the convergence commercialization of R&D technology based on regional characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.101-101
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• 2010

Anaerobic digestion(AD) is the most promising method for treating and recycling of different organic wastes, such as organic fraction of municipal solid waste, household wastes, animal manure, agro-industrial wastes, industrial organic wastes and sewage sludge. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is a mixture of carbon dioxide and methane. AD has been one of the leading technologies that can make a large contribution to produce renewable energy and to reduce $CO_2$ and other green-house gas(GHG) emission, it is becoming a key method for both waste treatment and recovery of a renewable fuel and other valuable co-products. Currently some 80% of the world's overall energy supply of about 400 EJ per year in derived from fossil fuels. Nevertheless roughly 10~15% of this demand is covered by biomass resources, making biomass by far the most important renewable energy source used to date. The representative biofuels produced from the biomass are bioethanol, biodiesel and biogas, and currently biogas plays a smaller than other biofuels but steadily growing role. Traditionally anaerobic digestion applied for different biowaste e.g. sewage sludge, manure, other organic wastes treatment and stabilization, biogas has become a well established energy resource. However, the biowaste are fairly limited in respect to the production and utilization as renewable source, but the plant biomass, the so called "energy crops" are used for more biogas production in EU countries and the investigation on the biomethane potential of different crops and plant materials have been carried out. In Korea, with steadily increasing oil prices and improved environmental regulations, since 2005 anaerobic digestion was again stimulated, especially on the biogasification of different biowastes and agro-industrial biomass including "energy crops". This study have been carried out to investigate anaerobic biodegradability by the biochemical methane potential(BMP) test of animal manures, different forage crops i.e. "energy crops", plant and industrial organic wastes in the condition of thermophilic temperature, The biodegradability of animal manure were 63.2% and 58.2% with $315m^3CH_4/tonVS$ of cattle slurry and $370m^3CH_4/tonVS$ of pig slurry in ultimate methane yields. Those of winter forage crops were the range 75% to 87% with ultimate methane yield of $378m^3CH_4/tonVS$ to $450m^3CH_4/tonVS$ and those of summer forage crops were the range 81% to 85% with ultimate methane yield of $392m^3CH_4/tonVS$ to $415m^3CH_4/tonVS$. The forge crops as "energy crops" could be used as good renewable energy source to increase methane production and to improve biodegradability in co-digestion with animal manure or only energy crop digestion.

• Food Science and Preservation
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• v.16 no.2
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• pp.266-275
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• 2009

To develop new high-quality Yakchobugak, features of Lactococcus lactis-fermented waxy rice paste after addition of some colored powdered agro-food products were investigated. Total and reducing sugars of waxy rice paste fermented by lactic acid bacteria were higher than those of control raw waxy rice paste. Total acidity gradually increased as powder concentration rose, being 1.02-1.56% and 0.96-1.87% in samples fermented with Cucurbita maxima and Capsicum annuum powders, respectively; these values were 3-4 times those in rice fermented with other powders. Fermented waxy rice paste viscosities were lower than those of non-fermented samples. The viscosities of samples fermented with Curcuma longa and Opuntia ficus powders were in the range $100-160{\times}10^4$ centipoise($mPa{\cdot}s$), and those of pastes fermented with Robus coreanus and Camellia sinensis extracts were under $40{\times}10^4mPa{\cdot}s$. Hunter color lightness(L) values decreased and yellowness(b) values rose after fermentation. Waxy rice paste fermented with Robus coreanus showed uniform particle size distribution, and many pores, by scanning electron micrography.