• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.358-364
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• 1995

In order to determine the moisture content level for safe storage of wild vegetables, drying characteristics and water vapor sorption characteristics of four vegetables, i.e., zucchini slice, sweet potato stem, taro stem, and platycodon, were investigated. The drying curves of these vegetables were consisted of three characteristic stages which were the initial settling down period, the constant drying rate period, and the falling drying rate period. And the falling rate period of the vegetables showed 2 or 3 parts of falling rate. All of the falling rate curves of the vegetables showed upwardly convex shape which is known as a characteristic pattern for the drying of fibrous food materials. The critical moisture contents of the vegetables were $8.29{\sim}9.75,\;10.40{\sim}15.08,\;9.51{\sim}14.52\;and\;3.29{\sim}3.56g\;H_2O/g$ dry solids for zucchini slice, sweet potato stem, taro stem, and platycodon, respectively. Activation energy values of drying rate during falling rate period were 2.30, 2.11, 4.97, and 2.80 kcal/mol for zucchini slice, sweet potato stem, taro stem, and platycodon respectively. The BET monolayer moisture contents of the vegetables were $10.05{\sim}13.59,\;9.49{\sim}12.69,\;9.50{\sim}16.48\;and\;5.01{\sim}5.44g\;H_2O/g$ dry solids for zucchini slice, sweet potato stem, taro stem, and platycodon, respectively. And these values were found to be very compatible with the values of the critical moisture content. Consequently, it was found that the moisture of these vegetables should be removed below the BET monolayer moisture content or below the critical moisture content for the long term storage.

• Journal of Food Hygiene and Safety
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• v.38 no.1
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• pp.31-36
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• 2023

This study was conducted to evaluate the efficacy of sodium hypochlorite in eliminating Escherichia coli strains from leafy green and stem vegetables, which are frequently sold at community service centers. A cocktail of non-pathogenic E. coli and enterohaemorrhagic E. coli (E. coli O157:H7) was used to artificially contaminate the vegetables (initial numbers of bacteria 7-8 log CFU/g). The contaminated vegetables were soaked in sodium hypochlorite for 5 min and then washed three times with running water. After the treatment, number of viable bacterial cells on the vegetables was estimated. Sodium hypochlorite treatment reduced the E. coli population by 1-2 log CFU/g on leafy green and stem vegetables, a significant reduction from the initial number. Further, sodium hypochlorite showed better antimicrobial efficacy for leaves with a larger surface area, less roughness, and softness. There was no significant difference in the antimicrobial effect between 100 and 200 mg/kg of sodium hypochlorite. Therefore, it is not necessary to increase sodium hypochlorite concentration than the level suggested in the school meal hygiene management guidelines. However, sodium hypochlorite treatment is not sufficient to achieve a safe level of microorganisms on leafy green and stem vegetables since they generally have a high abundance of microorganisms on their surface. Thus, an alternative cooking method for fresh leafy green and stem vegetables in summer should be developed to ensure they are safe for consumption.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.87-93
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• 2019

Revision work on the Codex Classification of Foods and Animal Feeds was undertaken in 2007 and presently, revisions for most food groups have been completed. For vegetables, the work was conducted during 2014-2017, and the final draft revision was adopted by the $40^{th}$ Codex Alimentarius Commission (2017). Here, the revised classification of vegetable commodities is introduced in order to be utilized in various food-related fields, in particular, food safety regulation. The revised classification is briefly summarized as follows: Codex classified vegetables into 10 groups (Group 009-018): bulb vegetables (Group 009), Brassica vegetables (except Brassica leafy vegetables) (Group 010), fruiting vegetables, Cucurbits (Group 011), fruiting vegetables, other than Cucurbits (Group 012), leafy vegetables (including Brassica leafy vegetables) (Group 013), legume vegetables (Group 014), pulses (Group 015), root and tuber vegetables (Group 016), stalk and stem vegetables (Group 017) and edible fungi (Group 018). The groups are further divided into a total of 33 subgroups. In the Classification, 430 different commodity codes are assigned to vegetable commodities. Meanwhile, Korea's Ministry of Food and Drug Safety (MFDS) does not include potatoes, beans and mushrooms within a vegetable group. In addition, the MFDS divides one vegetable group into six subgroups including flowerhead Brassicas, leafy vegetables, stalk and stem vegetables, root and tuber vegetables, fruiting vegetables, Cucurbits, and fruiting vegetables other than Cucurbits. Therefore, care is needed in using the Codex Classification.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.3
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• pp.201-206
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• 2016

Consumers are more aware of their health and more conscious of environmental conditions nowadays. As such, there is an increasing demand for agri-foods obtained from organic agricultural practices. The present study aims to compare quality characteristics and antioxidant activities between organically and conventionally grown perilla leaf, leaf lettuce, broccoli, and cabbage. The conventionally grown leafy and stem vegetables showed significantly (p<0.05) higher weights and lengths. There was no significant difference in moisture contents of organically and conventionally grown vegetables. The L (lightness), a (redness), and b (yellowness) values of organically and conventionally grown perilla leaf, leaf lettuce, broccoli, and cabbage showed significant differences (p<0.05). Conventionally grown perilla leaf, leaf lettuce, and broccoli showed significantly (p<0.05) higher DPPH and ABTS radical scavenging activities. Overall, the quality characteristics of conventionally grown leafy and stem vegetables were higher than those of organically grown ones. On the other hand, antioxidant activities of organically grown leafy and stem vegetables were higher than those of conventionally grown ones. Further studies are recommended to evaluate other differences such as flavor, organic acid, polyphenol, vitamin, mineral, and bioactivity compounds between organically and conventionally grown vegetables.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.164-169
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• 2023

Vegetables are rich sources of dietary fiber, which exhibit various health benefits. In the Republic of Korea, vegetables are consumed after cooking using different methods. However, they are most commonly eaten raw or blanched. In this study, chamnamul, sesame leaf, Fischer's ragwort, burdock root, and garlic stem from Korea were analyzed according to the Korean Food Code, and changes in dietary fiber content after blanching were compared. Blanching reduced the total dietary fiber (TDF) content in chamnamul (from 3.67±0.03 to 2.61±0.14 g/100 g), burdock root (from 4.95±0.40 to 3.89±0.10 g/100 g), and sesame leaf (from 4.32±0.12 to 3.65±0.17 g/100 g), but increased it in Fischer's ragwort (from 6.09±0.49 to 6.43±0.01 g/100 g) and garlic stem (from 4.52±0.35 to 5.09±0.04 g/100 g). Sucrose, glucose, and fructose were detected in the vegetables; however, sesame leaf did not have sucrose. Fresh burdock root had the highest sucrose content (1.71±0.07 g/100 g) whereas garlic stem had the highest glucose and fructose content (1.65±0.02 and 1.73±0.02 g/100 g, respectively) compared with other vegetables. Upon blanching, the free sugar content of vegetables decreased for all sugars except for sucrose, which increased in Fischer's ragwort (from 0.10±0.01 to 0.14±0.01 g/100 g) and garlic stem (from 0.76±0.00 to 0.83±0.01 g/100 g). These results can provide information on blanching-associated changes in the content of dietary fiber and free sugar in foods prepared using these vegetables.

• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.43-53
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• 2012

In order to monitor the levels of pesticides in environment-friendly stalk and stem vegetables and leafy vegetables selling at markets in Korea. A total of 637 (395 organic agricultural products, 242 pesticide-free agricultural products) samples of 21 stalk and stem vegetables and leafy vegetables were collected twice from markets in July and August 2010 in Korea. Pesticide residues in samples were analyzed by multiresidue method for 240 pesticides using GC-ECD/NPD and HPLC-DAD/FLD. The suspected-pesticides were confirmed with a GC-MSD. As a result of analysis, six pesticides were detected from eight samples, representing a detection rate of 1.3% and amounts of pesticide residues in samples were as follows: alachlor 0.043, chlorfenapyr 0.022-0.324, diazinon 0.024, dicofol 0.009-0.138, dithiopyr 0.008, metolachlor 0.025 mg/kg. Their residue levels were below the MRLs. Estimated daily intakes (EDIs) of the pesticides detected from stalk and stem vegetables and leafy vegetables were less than 25% of their acceptable daily intakes (ADIs), representing that residue levels of the pesticides detected were evaluated as safe for consumption. However, five samples containing pesticide residues were unsuitable environment-friendly products because of pesticides detected more than their 10% MRLs in organic and pesticide-free agricultural products.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.250-257
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• 2016

This study was conducted to extract the factors affecting the microbial safety of leaf and stem vegetables in the high school foodservice and to provide information for supplying the safe foodservice menu. The lunch and dinner menu (1,945 data) of the total 6 high schools at the Central and the South Region in March, June, September, and December were collected. The frequency analysis and the multiple correspondence analysis (MCA) based on the 3 factors (potentially hazardous food (PHF), leafy and stem vegetables in the menu, the cooking methods) were conducted. The most frequent PHF was the menu of blanched vegetables, salads, seaweeds and fried chicken. The most frequent consumed leaf and stem vegetables were spinach, chive, lettuce, Western cabbage, perilla leaf, iceberg lettuce, chicory, leek and broccoli. MCA based on the leaf and stem vegetables, the region, and the cooking method (cooked/non-cooked) showed that garlic stem and spinach were more used in the Central Region, while water drop-wort were more used in the South Region. Iceberg lettuce, Bok choy and leek were included frequently in the PHF menu. Plant products frequently used in PHF menu requires the food safety system such as Good Agricultural Practice (GAP) to reduce the microbial risk. The menu database according to raw materials based on cooking methods (heating or mixing) as well as the development and verification of menu based on the microbial safety will be contributed to provide the safer foodservice menu.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.167-172
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• 1991

The contents of dietary fiber and its physical properties of vegetables were determined. The samples selected in this study were soybean sprouts (Glycine max MERILL sprouts) butterber (Petasites japonicus MIQ), taro stem(Colcasia antiquorum SCHOTT stem), bracken (Pteridium aquilinum KUHN)and dried Korean cabbage leaves(Brassica compestris L.leaves). The contents of dietary fiber were 20.96~50.62% of neutral detergent figer, 10.60-38.19% of acid detergent fiber, 1.74-10.88% of lignin, 5.79~33.29% of hemicellulose and 5.79-33.29% of cellulose. Butterber had the highest dietary fiber content. Mean waterholding capacity of samples was 5.65-12.26g.water/g.acetone dried powder and butterber and dried Korean cabbage leaves had higher water holding capacity value than the others. Densities were 140-250mg/ml of direct density and 385-417 mg/ml of bulk density.

• Journal of the Korean Society of Food Culture
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• v.36 no.2
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• pp.143-157
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• 2021

This study aimed to analyze the periodic prevalence of the vegetables during the Joseon era with JoseonWangjoSilrok as a reference. The JoseonWangjoSilrok articles were collected from the Guksapyeonchanwewonhwe site, using web-crawling techniques to extract the relevant information. Out of 384,582 search results, 9,560 articles with vegetable-related keywords were found. According to the annual average vegetable recordings during the regimes of various kings, there were two peaking curves in the 15^th and 18^th centuryJoseon. The found was: 2,750 in the 18^th century, 2,529 in the 15^th century, 1,424 in the 16^th century, and 1,018 in the 19^th century. A Variable Interest Index was designed to ascertain the interestin vegetables of the 27 Joseon kings. The king most interested in vegetables was the 19^th king Sookjong. The second most interested king was Youngjo. There were 5,105 vegetable-related findings within the JoseonWangjoSilrok related to specific species and categories of vegetables. Among the words found: 1,194 were stem-leaves vegetables (23.39%), 1,017 were root vegetables (19.92%), 1,148 were flower-fruit vegetables (22.49%), 1,144 were spice vegetables (22.41%), 95 were mushrooms (1.86%), and 507 were seaweeds (9.93%). Statistical analysis using ANOVA revealed the chronological factors that affected the vegetables' prevalence index.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.365-374
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• 2020

This study was conducted to monitor the residual pesticides on a total of 320 stalk and stem vegetables from January 2019 to December 2019 in the Incheon metropolitan area. Pesticide residues in samples were analyzed by the multi-residue method for 373 pesticides using GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD and HPLC-UVD. Risk assessment was also carried out based on the amount of stalk and stem vegetables consumed. The linearity correlation coefficient for the calibration curve was 0.9951 to 1.0000, LOD 0.002 to 0.022 mg/kg, LOQ 0.005 to 0.066 mg/kg and recovery was 82.0 to 108.0%. According to the monitoring of pesticides, 36 (11.3%) of 320 were detected with pesticide residues and 3 (0.9%) samples exceeded the maximum residual limit. The detection frequency for Chinese chives and Welsh onion was higher than that for other stalk and stem vegetables. The frequently detected pesticides were etofenprox, procymidone, fludioxonil, and pendimethalin. As a tool of risk assessment through the consumption of pesticide detectable agricultural products, the ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was calculated in the range of 0.0062-24.1423%. These results indicate that there is no particular health risk through consumption of commercial stalk and stem vegetables detected with pesticide residues.