Raman Spectroscopy is a non-destructive analysis method without complex pre-processing and it can reduce the costs and time. A surface-enhanced Raman scattering (SERS) technique was tried to the detection of Benzo[a]pyrene which is one of the hazardous minor components of foods. To demonstrate the Raman signal enhancement effect by graphene as substrate, thymine was used as the standard material. As a result, the Raman signal of thymine has 102 enhancement. Herein, new SERS trials established to pursue improve the speed, simplicity and suitability of detecting minor components in foods.

Various methods for the detection of E. coli O157:H7 in food have been developed in the past decades. However, current detection methods require specialized instruments and lengthy preparation time. In an effort to achieve a rapid and sensitive detection, we developed a radial chromatography (RC) biosensor integrated with gold nanoparticle (AuNP) conjugated with antibody for the detection of E. coli O157:H7. The immuno-AuNP binds to E. coli O157:H7 creating AuNP-E. coli O157:H7 complexes by specific antigen-antibody interaction. The AuNP-E. coli O157:H7 complexes can be identified clearly from free AuNP by RC based on their mobility on porous matrix. Thus, the AuNP complexed with target bacteria, E. coli O157:H7 could be discriminated from free AuNP by radial chromatography. The results showed that the developed RC biosensor is highly selective to E. coli O157:H7 over non-target bacteria, including Bacillus cereus, Staphylococcus aureus and Vibrio cholerae with a detection limit of 105 CFU/ml. When combined with a pre-concentration step using immunomagnetic beads, we could further enhance the detection limit down to 103 CFU/ml. In this study, we developed a novel method that is rapid, sensitive and applicable for qualitative and quantitative detection of E. coli O157:H7. The detection procedure is simple and the results can be easily determined by naked eyes, suggesting that this system is practical and can be applied to the field diagnosis in food industry for the detection of pathogenic bacteria.

Quality changes of carrots thermally processed in a large size (5 kg) retort pouch during 52 weeks of storage period were investigated upon different packaging methods and package shapes. To improve the efficiency of thermal processing (121.1°C, 0.15 MPa), the carrot (i.e., solid) and the broth (i.e., liquid) of carrot soup were separately packed and sterilized. The quality changes of carrot packed without liquid were compared with those with liquid. Two different package shapes such as rectangular parallelepiped and cube were also evaluate to figure out the efficiency of the heat penetration rate for the large size of pouch. The location of cold points and the total thermal processing time (TTT) were different upon the treatment. Fo-values, satisfying the TTT to at least 6 min, were 27, 54, and 114 min from the rectangular parallelepiped, cube and solid/liquid mixed group, respectively. In the mixed groups, the hardness and chewiness of solids (carrot) was significantly smaller than that measured in the other groups as TTT increased. Carrots treated in the rectangular parallelepiped shape showed a significantly higher texture than the cube shape for both immediately after the thermal treatment and during the storage period. Coefficient of variation (CV), which indicates the quality variation within the same treatment, of texture properties obtained from the outside and the center of the sample were compared to evaluate the quality variation within the same treatment. The CV of hardness and chewiness of the rectangular parallelepiped and the cube shape were calculated 7.56 and 47.19, and 29.16 and 65.28, respectively. This demonstrated that more uniform quality could be expected from the thermal treatment in the rectangular parallelepiped shape

Recently, there is a growing interest of consumers in natural products thus a large number of natural preservatives have been studied as food additives. Among those natural preservatives, rosemary extract are commonly used by the food industry to extend the shelf life of several products. Nevertheless, the incorporation of the rosemary extract in food matrix is highly limited due to the low water solubility and poor chemical stability of constituents of rosemary extract. In this context, it is needed to find a way that can improve the water solubility to incorporate rosemary extract into aqueous system like foods. Hence, in this study we added surfactants that have a relatively high hydrophilic-liphophilic balance number into rosemary extract solution to increase the water solubility of rosemary extract and then investigated the microbial activities of rosemary extract with surfactants. Tween 20, decaglycerol monooleate, decaglycerol laurate and decaglycerol myristate were used in a range 0.1~4% and rosemary-surfactant solution was prepared by dissolving rosemary in surfactant added phosphate buffer (pH 7) as much as extract can be dissolved. Water solubility of rosemary-surfactant solution were examined by observance of the UV-vis spectra. The antimicrobial effects rosemary-surfactant solution on B.subtilis were also examined by paper disc diffusion method. Rosemary extract showed poor solubility in normal phosphate buffer but its water solubility was highly increased when surfactant was added. This tendency was lasted at all types of surfactant. This is because of amphipathic property of surfactant. Antimicrobial effect to B.subtilis was observed when a relatively lower concentration of surfactants were used, however, not in high concentrations. This result might be attributed to the formation of surfactant micelles containing rosemary extract when a relatively higher concentration of surfactants were used. The information presented may be useful for the development of a new rosemary-loaded delivery systems.

Strawberry jelly as a universal design food was developed using strawberry juice (SJ), sugar, xanthan gum (XG), and locust bean gum (LBG). Experimental variables included SJ concentration (30-40% (w/w)), sugar concentration (7.5-10.0% (w/w)), and the ratio of XG/LBG (0.3-4.0% (w/w)), and response variables were textural (hardness, gumminess, chewiness) and color properties. The formulation of strawberry jelly was optimized against hardness and the interactions among variables were predicted using the response surface methodology. Controlled storage test at 5 or 15°C was conducted to determine the values of the jelly at different temperatures. The optimal SJ and sugar concentrations and the ratio of XG/LBG against hardness were 40, 10, and 1.5%, respectively. The color did not change significantly during storage at 5 and 15°C (p>0.05). However, the textural characteristics during storage increased significantly at 5°C (p<0.05) and the hardness was appropriate to be used as a criterion for determining the shelf life of the jelly. The shelf life at 5°C generated from a zero-order kinetics (R²=0.96) was 40 d according to a criterial value, 1.8 N, of hardness. The Q10 value was calculated as 0.6, which allowed prediction of the shelf life values at different temperatures. The results from this study suggested a formulation of strawberry jelly as a universal design food and allowed determination of the shelf life of the food product.

Heavy metals are typical contaminant in water and need to be removed because they are non-biodegradable and can accumulate in human body. To remove metal and other contaminants from water, chemical absorbents are widely used due to their low cost. Herein, hybrid materials comprised of amylose and single wall carbon-nanotube (swCNT) was developed as the absorbent for water purification. A high adsorption properties of carbon-nanotubes have been utilized in designing effective absorbent but its poor dispersity in water is a limiting factor for practical use. Single wall carbon-nanotube was hybridized with amylose chain produced by enzyme reaction of amylosucrase and their tendency to self-assemble in aqueous environment. The amylose-swCNT microparticles were characterized by FE-SEM and turned out to be spherical structure with CNTs embedded throughout the amylose matrix. The ability of amylose-CNT microparticles to remove copper was examined. Concentration of copper was decreased after reaction with amylose-swCNT microparticles. Although amount of decreasing copper was less than swCNT on same total mass, Adsorption efficiency of amylose-swCNT microparticles was good because their swCNT content was only 10% of total mass.

Effects of superheated steam (SHS) temperature (120, 150, 180, 220°C) and time (2, 5, 8, 10 min) on physicochemical properties of garlic chips were examined. Higher the SHS temperature, a faster drying rate was observed due to the lower extent of water condensation on the garlic chip’s surface at the initial stage of treatment. Garlic chips treated at 220°C for 10 min showed the lowest water content and water activity. However appearance of these was inappropriate due to burnt spots on the surface. Scanning electron microscope analysis showed that garlic chips treated at higher SHS temperature showed compressed smooth cell layers at the surface with more compact internal structure due to higher degree of dehydration when compared to chips treated at lower temperature. These results confirmed that SHS could be utilized as an effective drying method for the production of garlic chips. Moreover, it is recommended that SHS treatment combined with other conventional post drying process would result in garlic chips with better quality in terms of color.

Effects of superheated steam (SHS) temperature (120, 150, 180, 220°C) and time (2, 5, 8, 10 min) on product quality attributes of snack-type ginseng chips were studied. Ginseng chips dried at faster rate under a higher SHS temperature. Higher SHS temperature resulted in ginseng chips with lower moisture content and water activity. After SHS treatment, lightness (L values) and redness (a values) of ginseng chips decreased significantly whereas yellowness (b values) of those increased. Although crude saponin content in ginseng chips reduced slightly after SHS treatment, chips treated at 150°C for 5 min had the highest saponin retention among samples. Scanning electron microscope analysis revealed that SHS treatment cause the shrinkage at the surface first, forming compressed cell layers. As treatment proceeded, pores and cavities were formed internally, resulting porous structure. These results suggested that SHS treatment shows great promise in production of snack-type ginseng chips by reducing drying time without any quality deterioratio

본 연구에서는 국내산 냉동 무의 품질 향상 및 보존을 위한 냉동 및 전처리 조건을 수립하고자 하였다. 국내산 무 를 3 cm 정방형으로 세절한 뒤 자연대류 냉동, 과냉각 후 냉동, 알긴산 침지 냉동, 알긴산 코팅 냉동을 실시하였다. 과냉각 후 냉동 처리는 무를 항온 저온 수조에서 느리게 냉각시켜 빙핵 형성이 야기된 이후 냉동고로 옮겨 후냉동을 실시하였다. 알긴산 침지 냉동은 1% sodium alginate 수용액에 무를 침지 시킨 후 즉시 냉동처리를 실시하였고, 알긴산 코팅 냉동은 1% sodium alginate 수용액에 무를 약 1분간 표면에 코팅 한 후 냉동하였다. 모든 냉동 처리구는 -18°C 자연 대류식 냉동고에서 실시하였다. 해동은 유수해동 (20°C)으로 진행하였다. 알긴산 침지냉동과 알긴산 코팅 냉동 처리구는 해동감량, 전단력 측면에서 모두 자연대류 냉동 처리구보다 우수한 결과를 나타내었다. 전단력의 경우, 자연 대류 냉동 처리구는 대조구보다 증가된 결과를 보였으나 알긴산 침지 및 코팅 처리구는 대조구와 유사한 결과를 나타 내었다. 또한 해동감량 역시 자연대류냉동 처리구가 알긴산 침지 및 코팅냉동 처리구보다 높은 값을 나타내었는데, 이 는 냉동 및 해동 과정에서 조직이 파괴되어 야기된 것으로 판단되었다. 알긴산 처리구 간의 특성을 비교하였을 때, 침 지 냉동 처리구가 코팅 냉동 처리구보다 더 우수한 결과를 나타내었다. 이 결과를 토대로 sodium alginate를 통한 전처 리가 냉동 무의 품질유지에 영향을 끼친 다는 것을 알 수 있었고, 최적 조건으로는 1% Sodium alginate 수용액 침지냉 동으로 평가되었다. 따라서 sodium alginate 처리는 냉동농산물의 전처리 방법으로서 품질유지 및 향상에 기여할 것으 로 예상되었다.

The pasteurization is employed for extending shelf-life and keeping the quality of products constant. However the pasteurization undesirably accelerates the oxidation of beer which renders volatile compounds concerning off-flavor. The pasteurization conditions was optimized to avoid off-flavor of beer during pasteurization. Under the isothermal condition, thermal destruction kinetics such as D and Z value of Lactobacillus brevis which is reported the most common beer spoilage, was determined. The binomial data (detected or non-detected of off-flavor) was treated with logistic regression to estimate off-flavor development (OFD) times. The temperature dependence of OFD times was established in terms of Arrhenius relationships. Optimized pasteurization temperature and time were found at which OFD times was not detected. The constraint for optimization was that the pasteurization degree should be larger than 5 decimal reduction time. The optimization was conducted through mathematical simulation using kinetics and temperature-dependent models for microbial death and OFD times. The optimized results were validated by the corresponding experimentations, which met the requirements that the concentration of Lactobacillus brevis was 5-Log reduction and the OFD times not detected.

Biogenic amines (BAs) are toxic nitrogenous compounds and formed by the microbial decarboxylation of amino acids during fermentation. Consumption of fermented foods high in BAs can pose the adverse health effects. The objective of current study was to develop a reduction method of BAs in fermented soybean paste by applying catechins during fermented koji manufacturing step. Analysis of BAs in fermented soybean paste was conducted using High Performance Liquid Chromatography (HPLC). The levels of Putrescine decreased for 63.7%, 60.1%, 76.1%, 73.4% for 0.3% addition of Epicatechin, Epicatechin gallate, Epigallocatechin, Epigallocatechin gallate, respectively. The levels of Cadaverine decreased for 24.3%, 34.3%, 42.6%, 37.2% for 0.3% addition of Epicatechin, Epicatechin gallate, Epigallocatechin, Epigallocatechin gallate, respectively. Especially, The best reduction effect of BAs appeared for 0.3% addition of Epigallocatechin. Current study demonstrated the potential use of catechins for reduction of biogenic amines in fermented soybean paste model. Finding from this research can practically guide fermented food industry by providing practical application of additives for reduction of BAs.

4(5)-methylimidazole (4(5)-MI) is carcinogenic, nitrogen-containing compound, mainly found during the manufacturing of caramel coloring. Hence, presence of 4(5)-MI is well-known in any food products with addition of caramel coloring for desirable sensory characteristics, such as cookies. Limited work has been conducted to develop suitable analytical method and to investigate effect of caramel coloring in cookies. This study aimed at developing the analytical method for quantification of 4(5)-MI and confirming influence of caramel coloring on level of 4(5)-Mi in cookies. Gas chromatography-mass spectrometry (GC-MS) was utilized for qualification and quantification of 4(5)-MI. Sample preparation procedure specialized in bakery products was fully developed in this study. The concentration of 4(5)-MI in 15 commercial cookies and biscuits ranged from 71.5 to 1254.8 ng/g. Correlation equation (y = 706.42x + 21.792) was obtained to estimate effect of caramel colorant on level of 4(5)-MI in cookies. Further, analytical method developed and results of correlation equation can be utilized in future studies on reduction of 4(5)-MI in many food.

청주 제조시 최적의 품질유지를 위한 청징 및 여과방법을 검토하고자, 청징제로 사용되는 벤토나이트와 젤라틴의 사용량을 달리하고, 여과보조제인 활성탄과 규조토의 사용량을 달리하여 청징효과와 품질특성 변화를 파악하였다. 흡 광도에 탁도 분석을 통한 청징효과는 벤토나이트 단독 사용시 젤라틴 단독사용, 젤라틴과의 혼용보다 효과가 컸으며, 벤토나이트 사용량이 많을수록 청징효과는 컸으나 증가폭은 감소하였다. 벤토나이트의 사용량이 많을수록 ethyl acetate와 고급알코올(n-propanol, i-butanol, i-amyl alcohol) 등의 휘발성 향기성분은 소폭 감소하였다. 활성탄과 규조토 의 사용량을 달리한 후 여과포를 거친 여과효과는 규조토의 사용량에 따른 청징효과는 크지 않았다. 반면 활성탄 200ppm 사용시 청징효과가 가장 컸으며 400ppm 이상의 활성탄 사용시는 역으로 탁도가 증가하였다. 활성탄을 많이 사용할수록 ethyl acetate는 감소하였으나 고급알코올의 변화량은 크지 않았다. 벤토나이트 사용량을 달리하고 활성탄 투입(200ppm) 및 규조토를 이용한 여과포에 의한 여과를 동시에 진행하였을 때 벤토나이트 750 ppm 사용시 청징효과 가 가장 큰 것으로 나타났다.

In this study, the use of corona discharge plasma jet (CDPJ) for the improvement of hygienic quality of semi-dried mackerel pike (Gwamegi) was investigated. Different microbial contaminants, namely aerobic and marine bacteria, coliform bacteria, Staphylococcus aureus and yeasts and mold, were detected in the range 4.2-6.2 log CFU/g in Gwamegi samples. The CDPJ generated using 20 kV DC and at 58 kHz frequency was used for the treatment of Gwamegi for 0-10 min. The bacterial contaminants were inactivated in the range of 1.9-3.3 log CFU/g on the treatment for 10 min. Additionally, yeasts and mold were inactivated by 3.2 log CFU/g. The inactivation pattern fitted well to the first-order kinetics model. The CDPJ treatment for 10 min did not exert statistically significant changes (P > 0.05) in pH, moisture content, water activity, peroxide value, acid value and volatile basic nitrogen content of Gwamegi in comparison to untreated control samples. On the contrary, significant changes (P < 0.05) were noted in color and thiobarbituric acid reactive substances levels upon the CDPJ treatment. However, the CDPJ-treated Gwamegi samples displayed better sensory properties in terms of appearance, visual color, and flavor as compared to controls.

In this study, a two-factor-six-level factorial design was adopted for optimizing brine (saturated salt solution) and water flow rates in electrolyzed water generator in order to produce electrolyzed water (EW) having best performance for vegetable washing. The pH, electro-conductivity, chlorine contents of produced EW were determined. The optimum EW for broccoli sprouts washing was produced at flow rates of brine and water of 100 mL/min and 300 mL/min respectively. The optimum washing time was 20 s based on the quality of washed broccoli sprouts. The microbial counts were decreased by 1.4 log for aerobic bacteria and 1.0 log for yeasts and mold. The functional quality and sensory characteristics of broccoli sprouts were unaffected by the EW washing. The results demonstrated the applicability of EW for the improvement of hygiene of broccoli sprouts without affecting quality.

Ginsenosides are sensitive to various factors such as pH, temperature, ionic strength, etc. However, powdery form of ginseng is good to preserve ginsenosides in it compared to the extracted form. In addition, the ginseng powder can provide pickering effect to control emulsion stability as a substitute of emulsifier forming wall on the surface of oil. A ginseng pickering emulsions was prepared by mixing, MCT oil, polysorbate 80 and ginseng. Thereafter, to homogenize the emulsions magnetic stirrer, homogenizer and ultra sonicator were used. The physicochemical properties, stability, and bioaccessibility of the ginseng pickering emulsion were investigated. Both particle size and polydisperse index of the ginseng pickering emulsion were constant as time elapsed. However, pH and zeta-potential of the ginseng pickering emulsion decreased over time. Moreover, to find out the proper amount of ginseng powder, different ginseng powder weights were added to sample respectively and the physiochemical characteristics were measured. The pH and zeta-potential value tended to decrease following increase of amount of ginseng powder. This result is impacted to food quality and it could be used as a preliminary result in the development of food product.

Nanoemulsions containing Turmeric extract were fabricated using ultrasonication (US) system and their physicochemical properties were characterized by mean droplet size, size distribution, zeta potential, and morphology. Turmeric was firstly extracted using 50% ethanol with heating and concentrated to increase the solid content. The final curcumin content in the concentrated turmeric extract was 10.4 mg/mL. Medium chain triglyceride (MCT) oil was selected as an oil phase by the solubility test. Turmeric extract-loaded nanoemulsions (TE-NEs) were prepared with oil phase containing lecithin and water phase containing tween 80 by ultrasonication treatment. The mean droplet size of TE-NEs was significantly decreased with ultrasonication time and ranged from 66 nm to 279 nm. The optimum HLB (hydrophilic lipophilic balance) value was 10.6 which decided to obtain the smallest droplet size and the highest zeta potential of TE-NEs. TE-NEs showed good storage stability at 4°C for 30 days without any phase separation and significant change of both mean droplet size and zeta potential. Transmission electron microscope (TEM) images support that the droplet of TE-NEs was individually spherical shape and not aggregated or agglomerated until the TE concentration was less than 500% (w/w MCT oil).

보리, 밀 등에서 발생되는 붉은곰팡이병균(Fusarium)은 전세계적으로 분포하고 있으며 작물의 수확량을 감소시키고 품질을 저하시키는 원인이 된다. 특히, 곰팡이병균은 deoxynivalenol(DON), nivalenol(NIV), zearalenone(ZEA) 등과 같은 제2차 대사산물인 곰팡이 독소를 생성하여 사람과 가축에 치명적인 피해를 주기도 한다. 발암물질로 알려진 곰팡이독 소는 조리 및 가공 후에도 분해되지 않는 특성으로 인해 오염된 곡물을 미리 검출하여 폐기해야 그 피해를 막을 수 있다. 기존 곰팡이독소 검출을 위해서는 정확성이 높은 TLC, HPLC, ELISA 등을 사용하고 있지만 고가 장비 및 전문 인력이 요구되고 있으며 분석을 위해 장시간이 소요되는 단점이 있다. 따라서 본 연구에서는 1175∼2170 nm의 근적 외선(NIR) 파장대역을 가진 분광센서를 이용하여 곰팡이독소(DON)에 오염된 겉보리 시료의 농도를 예측하고자 하였 다. 겉보리 시료에 적용된 곰팡이독소(DON)의 농도별로 0, 10, 100, 10000 ppm으로 각각 20립씩 총 80립을 조제하였 다. 용매는 아세트나이트릴에 침지하였으며 질소를 이용하여 건조시켜 곰팡이 독소를 조제하였으며 NIR 분광센서를 이용하여 총 3회 반복 측정하였다. 겉보리의 농도별 곰팡이독소를 예측하기 위해서 교정 및 검정 PLSR(Partial least square regression) 모델을 개발하였으며 각각의 반사 스펙트럼 전처리별 R2, SEC, SEP 등의 값을 산출하여 예측성능을 비교하였다.

The purpose of this research was to prepare silibininloaded nano sized liposomes to improve their aqueous solubility and to optimize the preparation method. For the preparation, specific amount of cholesterol was dissolved into ethanol. After that, phosphatidylcholine from egg yolk (~60%) was dissolved into mixture about 20, 40, and 60 mg/mL, and subsequently, silibin in was dissolved into organic phase at approximate 250, 500, and 1000 μg/mL, respectively. The organic phase was regularly injected at 0.9 mL/min into phosphate buffered saline (PBS) using peristaltic pump under stirring. Liposomes were formed spontaneously as soon as lipid phase was in contact with the aqueous phase. Then, the liposome suspension was kept under stirring for 15 min. Thereafter, ethanol was removed by rotary evaporation under reduced pressure. As the result, silibin in loaded liposomes were circular shape which had lipid bilayer at edge of the liposome droplets and were multilamellarvesicles. In addition, average size of silibinin loaded liposome droplets were 148.27, 144.52, and 173.46 nm at 250, 500, and 1000 μg/mL silibinin concentrations, respectively. Zeta potentials of liposome particles were showed about -9.64, -12.03, and -12.79 mV. As concentration of phosphatidylcholine in ethanol increased, droplet size and zeta potential of the liposome increased. The average encapsulation efficiency of obtained liposome suspensions was 57.6%. In conclusion, the liposome preparation method established can be used to encapsulate various hydrophobic bioactives for food application such as beverage.

The purpose of this research was to observe the quality changes of beef and blueberry during frozen storage. Drip loss, thiobarbituric acid reactive substance (TBARS) content, polyphenol content, and moisture content in the beef and blueberry were measured to determine the quality change of beef and blueberry for 29days. As a result, drip loss changed from 2.35 to 3.80%, and TBARS content changed from 0.11 to 0.30 mg MDA/kg beef for 29days. Both results showed that drip loss and TBARS content increased by 1.7times compared to those at initial samples. However, the frozen storage condition in this study is recognized as proper for beef preservation since the TBARS content below 0.46 mg MDA/kg beefis regarded to be edible. Polyphenol content and moisture content changed from 3.07 to 3.11 mg Gallic acid equivalent (GAE)/g blueberry and from 0.44 to 0.27%, respectively. There were no significant differences in polyphenol and moisture contents. In conclusion, frozen storage of beef and blueberry had no adverse effect on their quality for 29 days.