Earticle

In this study, “Hongro” apples for test samples were selected from a market for aroma analysis. Analysis was done after 1 hr, in a forming headspace while maintaining a temperature of 25oC. First, the complex aroma of the apples was assessed by a Direct Sensory Method. Secondly, the complex aroma was analyzed under individual aroma conditions separated by GC/FID/Olfactometry. Finally, aroma component analysis by GC/MS was performed. Degrees of contribution of aroma components were evaluated by an aroma value calculation considering aroma duration time, frequency, and intensity. The contribution rate (%) of the aroma induction component influencing apple aroma was determined by aroma component analysis and aroma contribution degree. As a result, it was found that the top four components were as follows, by contribution rate (%): acetic acid (23%), 1-hexanol (16%), butyl ethanoate (13%), 4-methoxy-2-methylbutane (9%). These four components constitute the complex aroma tested by the direct sensory method, and was largely recognized by the apple aroma test panel. Consequently, it was found that these components are the key factors in apple aroma. If the mechanism of formation of these components can be found, it could have a significant influence on consumers’ acceptance of new varieties of apples.

Sesame oil was sometimes replaced by mixed oil due to high price in Korean market. To find out authentic sesame oil, electronic nose (E-nose) based on mass spectrometer system was used. Sesame oil was blended with perilla oil at the ratio of 97:3, 94:6, 91:9, 88:12 and 85:15, respectively. Intensities of each fragment from sesame oil by E-nose based on MS were completely different from those of perilla oil. The obtained data was used for discriminant function analysis. For quantitative analysis, the partial least square algorithm was used. The added concentration of perilla oil to sesame oil was correlated with discriminant function first score (DF1) and second score (DF2). From this relationship it could be found out how much perilla oil added. DFA plot indicated a significant separation of pure sesame oil and pure perilla oil. The different geographical origin of sesame oil was used for blending with perilla oil were closed to that of sesame oil. Korean sesame oil mixture and Indian sesame oil one were well separated. And the correlation between mixing ratios and DF1 values was found at the ratio of 97:3, 91:9, and 85:15 (SE vs PE oil), respectively. But the added concentration of perilla oil to sesame oil was correlated with discriminant function first score (DF1). E-nose based on MS system could be used as an efficient method for purity of oil quality.

In order to optimize the supercritical fluid extraction (SFE) conditions of volatile components from the strawberry, we conducted an evaluation of the sample preparation and SFE operating conditions. The analysis of the volatile components extracted by a variety of sample preparation protocols led to the identification of 30, 26, 30, and 34 volatile components in fresh, freeze-dried, 30% celite and 70% celite treatments, respectively. The 70% celite treatment was the most effective in extracting the volatile components from strawberry via SFE. Analysis of the volatile components extracted by a variety of SFE operating conditions yielded identifications of 34, 35, 34, and 35 volatile components at 3,000 psi (40, 50oC) and 6,000 psi (40, 50oC), respectively. The extraction yield of alcohols and acids, and the total volatile component contents, were highest under conditions of 3,000 psi and 55oC. Volatile components from the strawberry were extracted via SFE, simultaneous steam distillation and extraction (SDE), and solvent extraction (SE). The analysis of the volatile components extracted via different extraction methods resulted in the identification of 56, 34, and 32 volatile components in the SDE, SFE, and SE extracts, respectively. The total volatile component contents identified in the SDE, SFE, and SE extracts were 20.268±1.144, 21.627±1.215 and 2.476±0.177 mg/kg, respectively. The SFE extract evidenced higher contents of sweet flavors such as 2-methylbutanoic acid, 2-methylpropanoic acid, and hexanoic acid than the SDE and SE extracts. SFE proved to be the most appropriate method for the extraction of fresh volatile components from the strawberry.

The objectives of this study were to evaluate a protease suitable for the enzymatic hydrolysis of a snow crab processing by-product (SPB) and to optimize the hydrolysis conditions using response surface methodology (RSM). The SPB was hydrolyzed at 50oC and pH 7.0-7.2 to obtain various degree of hydrolysis (DH) using Flavourzyme at an enzyme/substrate (E/S) ratio of 3.0%. The reaction progress curve exhibited an initial fast reaction rate followed by a slowing of the rate. The DH was increased to 30% at 90 min with a final DH 32 to 36%. A central composite experimental design having three independent variables (reaction temperature, reaction time, and E/S ratio) with five levels was used to optimize the enzymatic hydrolysis conditions. Based on the DH data, the optimum reaction conditions for the enzymatic hydrolysis of the SPB were a temperature of 51.8oC, reaction time of 4 hr 45 min, and an E/S ratio of 3.8%. It was demonstrated that the enzymatic hydrolysate of SPB could be used as a flavoring agent or a source of precursors for the production of reaction flavors.

Autoxidative stability of wheat bran and germ oil extracted from Keumkang wheat (WBG-K) or Dark Northern Spring wheat (WBG-DNS) at 50oC in the dark was compared by peroxide values (POV) and fatty acid composition by gas chromatography. Changes of minor compounds were monitored by HPLC. WBG-K showed significantly higher linoleic but lower oleic acid content than WBG-DNS. WBG-DNS contained more phospholipids but less tocopherols and carotenoids than WBG-K. POV of oils was increased during storage, with no significant difference in the oxidation rates between two oils. Tocopherols, carotenoids, and phospholipids in both oils were degraded during the autoxidation. Total phospholipids content showed the highest correlation with the degree of oxidation in WBG oils. The results clearly showed that both fatty acid composition and contents of tocopherols, carotenoids, and phospholipids co-affected the autoxidation of WBG oil

Residual fluoroquinolone levels in animal foods retailed in Korea were monitored according to the method outlined in Korea Food Code using HPLC-FLD and HPLC-ESI-MS/MS for confirmation. The optimum ion transitions were 360→316, 342 m/z for enrofloxacin, 332→314, 288 m/z for ciprofloxacin, 320→301, 230 m/z for norfloxacin, 334→315, 290 m/z for pefloxacin, 362→318, 261, 334 m/z for ofloxacin, and 262→201, 126 m/z for flumequin. Enrofloxacin, ciprofloxacin and norfloxacin residues were found in 12 out of 388 samples. These antibiotics were only found in chicken samples, while no residues were found in beef, pork, milk and egg samples. Using this monitoring method, detection rates of 3.1, 1.3, and 0.3% were obtained for enrofloxacin, ciprofloxacin and norfloxacin, respectively. The levels of enrofloxacin, ciprofloxacin and norfloxacin detected in food samples ranged from 0.01 to 0.73 mg/kg in 12 samples, 0.01-0.03 mg/kg in 5 samples, and 0.12 mg/kg in only a sample, respectively

This study was conducted to investigate the effects of steeping periods and temperatures of waxy rice on the microflora and enzyme activities of steeping water and waxy rice, as well as on the microscopic structures of waxy rice during the preparation of gangjung. When the steeping water was 15 and 35oC, yeast and lactic acid bacteria were the major microflora after 1 day. After 11 days, Lactobacillus spp. were the major bacteria, while Bacillus spp. were the primary microflora after 21 days. At 25oC the primary species were Bacillus spp., Leuconostoc spp., and Bacillus spp. after 1, 11 and 21 days, respectively. The α-amylase activity of steeping water increased proportionally with the increase of temperature and period, while the protease activity tended to increase for 11 days, but decreased at 21 days. The enzyme activities of the steeped waxy rice, especially the α-amylase activity, decreased with higher steeping temperature, while the β-amylase and glucoamylase activity remained constant for up to 21 days. Observation using scanning electron microscopy indicated that intracellular cleavage of steeped waxy rice endosperm resulted in a rough surface morphology due to the exposure of polygonal starch granules. Tiny pinholes on the surface of waxy rice starch granules were also observed after steeping for 11 days.

A cylindrical ultraviolet (UV) sterilization system was developed for decreasing microorganisms in takju. The takju was passed through 110 strips of honeycomb-type teflon tubing with 9 UV lamps (1,395 W) set between the teflon tubes. Thus, during passage, the takju was effectively exposed to the UV rays without loss. In terms of the overall quality aspects of the takju, the optimum sterilization condition was set for 4 min at 2 L/min. A 2-3 log cycle decrease in viable cell numbers of total bacteria and fungi was observed at this operating condition. Quality changes in the UV-sterilized takju were examined via UV irradiation of samples followed by storage at 30oC for 8 days. To evaluate the quality changes, pH, amino nitrogen content, acidity, reducing sugar content, and viable cell numbers of total bacteria and fungi were measured. Increases in pH, acidity, and amino nitrogen content were observed in both the takju control and UV sterilized takju with increasing storage time. However, reducing sugar content was decreased in both samples. The L, a, and b values of the control takju and UV sterilized takju showed similar trends over the storage period. Viable cell numbers of fungi did not change in the control or UV sterilized takju during storage, showing approximately 108 CFU/ mL and 104-105 CFU/mL, respectively. In addition, viable cell numbers of total bacteria remained lower in the UV sterilized takju over 4 days compared to the non-sterilized takju.

Liquid microparticulated seaweed calcium was manufactured via a wet grinding process. Thereafter, different forming agents such as cyclodextrin, gum arabic, and Na-caseinate were added to the liquid calcium, which was then spray-dried to investigate the quality of the powdered calcium treatments. The moisture contents of samples were approximately 2%. It was also determined that the different kinds of forming agents did not affect the spray drying efficiency. In addition, calcium solubility was the highest in a solution of pH 2. In buffer solution and vinegar, the powdered calcium made with gum arabic showed the highest solubility among the treatments. The calcium contents of all the powdered microparticulate seaweed calcium samples were about 28%, and calcium content was not affected by the forming agents. The spray-dried calcium powder made by spray drying with gum arabic had the highest water vapor uptake, whereas the seaweed calcium was stable in terms of water adsorption. The results of SEM observations indicated that a portion of the spray-dried calcium powders were in nano-scale after wet-grinding. Among the treatments, the use of saccharides as a forming agent resulted in the most uniform particle distribution after spray-drying.

In this study, four Korean black raspberry wines were developed using raspberries from different regions in Korea; Gochang (G), Hoengseong (H), Jeongeup (J), Sunchang (S). Sample wines were monitored for titratable acidity, ethanol, pH, reducing sugar content, color intensity, hue, total phenolic content, and organic acids during alcoholic fermentation and aging. After fermentation was complete, the pH levels in the four wines were in a similar range (3.43-3.52), while total acidity levels ranged from 9.98 to 16.2 g/L, which were significantly different among the four wines. During 120 days of aging, the ethanol content ranged from 15.8 to 16.40% which corresponds to a good conversion rate of sugars. Among the four samples tested, the wine made with Jeongeup raspberries showed the highest levels of total phenolic content, and other color values such as hue and intensity. The predominant organic acids were citric acids (3.30- 4.89 mg/mL) and succinic acids (1.92-3.48 mg/mL). Overall the wine made with Jeongeup raspberries showed differences in physico-chemical compositions compared to the other wines made with Gochang, Hoengseong, and Sunchang raspberries, respectively.

Cookies containing wheat flour mixed with 10, 30 or 50% esterified with octenylsuccinic anhydride (OSA, 3%) and dry-heated (130oC, 2 hr) high amylose rice (Goami 2) starch (DH-OSAR) were prepared and then their physical and digestive properties were evaluated. When the amount of added DH-OSAR increased, the hardness and brittleness of the cookies decreased, and L (brightness) value increased. For the digestive properties, the cookies containing 50% DH-OSAR significantly increased the amount of slowly digestible starch (SDS), and decreased the amount of rapidly digestible starch (RDS), resulting in the lowest expected Glycemic Index (eGI) among tested cookies. Although the cookies containing DHOSAR were inferior to the control, the addition of xanthan gum (0.5% based on total powder amount) significantly improved their textural and sensory properties. Specially, the cookies containing 50% DH-OSAR and the addition of 0.5% xanthan gum showed the lowest eGI value, maintaining the improved textural and sensory properties.

This study was conducted to screen for plant food materials that improve human intestinal microflora, especially microorganisms associated with obesity. Among 30 tested plant food materials, the extract of Schizandra chinensis inactivated Eubacterium limosum, Bacteroides fragilis and Clostridium spp. Additionally, S. chinensis extract was also found to have a growth-promoting effect on Bifidobacterium spp.. The antimicrobial activity and antioxidant activity of the water extract did not decrease in respond to heating. Additionally, the water extract of S. chinensis did not show a toxic effect on the growth of Caco-2 cells. In vivo feeding tests were performed to investigate the influence of extract on the intestinal microflora in rats. Although the extract did not reduce obesity induced by a high fat diet, it led to significant increase in the population of Bifidobacterium spp. and a decrease in the population of Clostridium spp. in rats. Taken together, these results indicate that S. chinensis could be useful as a functional food component to control intestinal microbial flora.

Cronobacter spp. (Enterobacter sakazakii) is known to be highly resistant to dry conditions than any other Enterobacteriaeae. In this study, one hundred and ten Korean Cronobacter isolates were characterized to find out their survival characteristics under conditions of desiccation and humidity. Thirty percentage strains of the isolates showed high resistance to desiccation exposed on the metal surface for eight hours by half survival of the initial number, whileas less than 10% strains showed dry sensitivity by less one log scale survival among seven log scales. Finally, more than 90% of the strains consisted of dry-resistant and dry-intermediate groups. The same tendencies were evident in a 15-day exposure. Dry-resistant and intermediate strain groups showed 3 log scale survival among 5 log initial numbers in the powdered infant formula for 30 days, which were more resistant than on the above metal surface exposed. So, almost the isolate strains showed high resistance to dry condition. Dry-resistant and intermediate groups exposed on the metal surface formed a biofilm at the beginning, and the dry-sensitive group showed biofilm formation mainly only after a 7-day exposure. However, without a time difference in formation of biofilm, the dry-resistant and sensitive isolates seemed to similar biofilm formation activity. Most of the isolates showed very low survival at 75% relative humidity in 48 hours; however, they showed high resistance by 60% survival at 40% relative humidity. The Cronobacter isolates showed high resistance to desiccation on the metal surface and in the powdered infant formula, but low survival at high relative humidity. Therefore, high humidity may be a control method for Cronobacter in food processing environments.

This study was conducted to investigate the antioxidant activity, fibrinolytic activity and cytotoxic effect of Korean traditional noble rice wine made using different methods (A-C) and commercial rice wine (D-H) on various tumor cell lines. The antioxidant activity of rice wine was measured by DPPH (2,2-dipicryl-1-picrylhydrazyl), ABTS [2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid)] and NO (nitric oxide) radical scavenging assay. In this study, Samhaeju showed the greatest fibrinolytic activity of 13-17U and exhibited the highest antioxidant activity. Among the different Samhaeju, the sample prepared using method C had the highest antioxidant activity. The cytotoxic effect of rice wine were also examined against the human cancer cell line (A549 cells and HeLa cells) based on the results of a WST-1 assay and morphological changes. Rice wine induced the inhibition of cell proliferation and morphological changes in tumor cell lines in a concentration-dependent manner, with Samhaeju diluted 10 fold having the strongest effect on these factors. These findings suggest that Korean rice wine has antioxidant activity and cytotoxic effect, and that these factors are influenced by the method of preparation.

The antimutagenic activities of ethanol extracts of Korean and American propolis were tested using Salmonella Typhimurium TA98 with two indirect mutagens of 3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole (Trp-P-1) and 2-aminoanthracene (2-AA) with S9 mix. Additionally, their antimicrobial activities against acne-related pathogenic strains of Propionibacterium acnes, Staphylococcus Epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using both paper disk method and agar dilution method. Ethanol extracts of Korean and American propolis showed strong inhibitory effects, in a dose dependant manner, against the mutagenicities induced by Trp-P-1 and 2-AA. The antimutagenic effect of ethanol extracts of Korean propolis showed significantly higher protective activity than that of American propolis against the Trp-P-1 induced mutagenicity of S. Typhimurium TA98 at the lower concentration (1-10 μg), but significantly lower protective activity at the higher concentration (50-200 μg). The antimutagenic effect of ethanol extract of Korean propolis showed significantly higher protective activity than that of American propolis against the 2-AA induced mutagenicity at the concentration of 1 μg, but significantly lower protective activity than that of the American at the higher oncentration (50-200 μg). Both extracts showed strong antimicrobial activities against all the acne-related pathogens tested, with minimal inhibitory concentration (MIC) values in the range 1,500-5,000 μg/mL.

Several studies have demonstrated that chlorophyll has many beneficial properties, including anti-inflammatory, anti-tumor, and antioxidant properties. Chlorophyll has been also shown to have an excellent chemopreventive potential against skin tumor. Its preventive mechanism against skin tumor, however, has not been examined in detail. Furthermore, the effects of chlorophyll on UVB-induced cellular responses have not been investigated. Solar UV radiation, in particular its UVB component, is the primary cause of many adverse biological effects, which is responsible for the photoaging and skin cancer. We investigated the preventive effects of chlorophyll a on UVB-mediated responses in human immortalized HaCaT kerationocytes and normal human fibroblast. We found that treatment of chlorophyll a markedly inhibited UVBinduced generation of reactive oxygen species and lipid peroxidation. Chlorophyll a also prevented UVB-induced MMP-1 expression and MMP-2 activation and increased Type I pN collagen synthesis. These results suggest that chlorophyll a is a potent candidate for the prevention and treatment of UVB-induced skin cancer and photoaging.

Hepatoprotective effects of corn gluten hydrolysates (CGH) were investigated in rats orally treated with ethanol (30%(v/v), 3 g/kg body weight/day) for 4 weeks. Six-week old Sprague-Dawley male rats were divided into four dietary groups: normal diet (N), alcohol diet (E), E+CGH 1% diet (CGH-1%), and E+CGH 3% diet (CGH-3%). Body weights and liver indices were not significantly different among the four groups. However, food intakes were lower in the CGH groups than in the normal group (p<0.05). The administration of CGH significantly reduced serum alkaline phosphatase activity by 30% compared to the alcohol diet group. Among the antioxidative enzymes assessed, catalase activity was significantly decreased by 79% in the CGH diet groups compared to the alcohol diet group. In comparison to the alcohol-treated group, aldehyde dehydrogenase activity was increased by 20%, while microsomal ethanol oxidizing system activity was decreased by 20% in the CGH-treated groups. Furthermore, the area under the curve of the blood acetaldehyde concentration versus time profile after the administration of ethanol was significantly lower for the CGH rats than for the ethanol or asparaginic acid treated groups. Thus, CGH seems to offer beneficial effects by protecting against ethanol-induced hepatotoxicity by improving the acetaldehyde-related metabolizing system.

In this study, the antioxidant and neuronal cell protective effects of methanol extract from Schizandra chinensis were evaluated. The proximate composition and total phenolics content of the extract were as follows: 64.88% nitrogen free extract, 10.56% crude fiber, 10.22% moisture, 8.33% crude protein, 5.05% ash, 0.96% crude fat, and 83.04 mg/g of total phenolics. In assays the methanol extract of Schizandra chinensis presented ferric reducing/antioxidant power (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity in a dose-dependent manner. In a cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT), the methanol extract showed protective effect against H2O2-induced neurotoxicity, and lactate dehydrogenase (LDH) release into medium was also inhibited by various concentrations of extracts (68-80%). Cell viability after treatment of the methanol extract was higher than that shown for vitamin C (100 μM) using a neutral red uptake (NRU) assay. Therefore, these data suggest that the methanol extract of Schizandra chinensis may be useful for neurodegenerative diseases including Alzheimer’s disease.

The anti-allergic effect of the methanol extract of Zizania latifolia Turcz was investigated. Methanol extract of Z. latifolia Trucz did not display any cytotoxicity activities in the IgE-sensitized RBL-2H3 cells. The extract was found to inhibit compound 48/80-induced degranulation and antigen-induced β-hexosaminidase release as well as PMA plus A23187-induced TNF-α production in RBL-2H3 mast cells in a dose-dependent manner. Release of β-hexosaminidase, a marker for the release of histamine in mast cells, was inhibited with an IC50 value of 73.8 μg/mL. These results suggest that Z. latifolia extracts may be useful for the prevention of type I allergic reaction.

The residue distribution ratio of pesticides among the flesh, stem and leaves of hot peppers were investigated to assure the safety of pepper powder and pepper leaves. Mixed solutions of chlorothalonil (wettable powder), kresoximmethyl (water dispersible granules) and procymidone (wettable powder) were applied once onto pepper plants in a plastic film house. After 7 days, the fruits and leaves were harvested and the fruits were divided into the flesh and stems. Pesticide residues in each pepper part were then analyzed by gas chromatography. The results showed that the concentration ratios of the chemicals in the flesh:stem and flesh:leaf ranged from 1:2-5 and 1:11-39, respectively, depending on the chemical evaluated. The observed flesh:stem ratio indicates that the pesticide content of the pepper powder product can increase by 20% if pepper stems are included in the powder product. The Korea Food and Drug Administration does not set a pesticide maximum residue level (MRL) for pepper leaves if a residue ratio in leaves over flesh is more than ten times. Results from this study support non-MRL status on the pepper leaves for the studied pesticides. Additionally, we recommend that the chlorothalonil product of a wettable powder type include the phrase “prohibition of distribution or sale for pepper leaves as food” because chlorothalonil highly resided in pepper leaves as more than twenty-four times that is a criterion level to determine an inclusion of the phrase in the label of pesticide product.