• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.5
• /
• pp.694-698
• /
• 2020

The consumption of Gwamegi, a semi-dried saury Cololabis saira, and its vegetable sides has increased owing to its availability online. Therefore, this study investigated the microbial contamination levels in Gwamegi and its accompanying vegetable sides bought online by measuring total viable bacteria, coliforms, Escherichia coli, Staphylococcus aureus and fungi. The total viable bacteria ranged from 3-5 log CFU/g. The fungi in Gwamegi and garlic were 3.4 and 3.9 log CFU/g, respectively. The positive rate of bacterial contamination was 100% (2-3 log CFU/g) in Gwamegi, cabbage Brassica rapa subsp. pekinensis, and green chili Capsicum annuum, whereas the contamination positive rate was 80% and 60% (< 2 log CFU/g) in chives Allium ascalonicum L. and garlic A. sativum L., respectively. The positive rates of E. coli were 0%, 20%, 60%, and 40% in Gwamegi, green chili, cabbage, and chives, respectively. The contamination levels of E. coli were 1-2 log CFU/g. S. aureus was detected at < 1 log CFU/g in all raw materials. The data on microbial contamination levels may be used for microbial risk assessment of Gwamegi and vegetables for controlling the level of microbial contamination and securing microbiological safety.

• The Plant Pathology Journal
• /
• v.37 no.5
• /
• pp.476-488
• /
• 2021

Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot for cruciferous vegetables worldwide, especially for the cole crops such as cabbage and cauliflower. Due to the lack of resistant cabbage cultivars, black rot has brought about considerable yield losses in recent years in China. Understanding of the pathogen features is a key step for disease prevention, however, the pathogen diversity, population structure, and virulence are largely unknown. In this study, we studied 50 Xcc strains including 39 Xcc isolates collected from cabbage in 20 regions across China, using multilocus sequence genotyping (MLST), repetitive DNA sequence-based PCR (rep-PCR), and pathogenicity tests. For MLST analysis, a total of 12 allelic profiles (AP) were generated, among which the largest AP was AP1 containing 32 strains. Further cluster analysis of rep-PCR divided all strains into 14 DNA groups, with the largest group DNA I comprising of 34 strains, most of which also belonged to AP1. Inoculation tests showed that the representative Xcc strains collected from diverse regions performed differential virulence against three brassica hosts compared with races 1 and 4. Interestingly, these results indicated that AP1/DNA I was not only the main pathotype in China, but also a novel group that differed from the previously reported type races in both genotype and virulence. To our knowledge, this is the first extensive genetic diversity survey for Xcc strains in China, which provides evidence for cabbage resistance breeding and opens the gate for further cabbage-Xcc interaction studies.

• Korean Journal of Plant Resources
• /
• v.31 no.6
• /
• pp.622-633
• /
• 2018

Chinese cabbage grown during autumn season is confronted with drought conditions for a certain period, especially during the early growth stage. In this study, we investigated the effects of drought stress on plant growth characteristics, as well as free amino acid, carotenoid, and proline in Chinese cabbage. Chinese cabbage seeds (Bulam Plus) were germinated, and all the seedlings were transplanted into plastic containers (28 cm diameter ${\times}$ 22 cm high) containing a commercial growth medium. The soil water content was measured and maintained at 10% for the drought-stressed plants and at 30% for the control plants, for three weeks. The results revealed that plant growth parameters were lower in the drought-stressed plants than in the control plants. The total free amino acid content tended to decrease in both drought-stressed and control plants with time. The total free amino acid content was found to be lower in the drought-stressed plants than in the control plants and the proline content was unaffected. Moreover, at three weeks after treatment, carotenoid content in drought stressed plants was significantly higher than that in the untreated plants. We believe that our study makes a significant contribution to the literature because the effects of drought stress on plant growth parameters, free amino acid, carotenoids, and proline accumulation in autumn growing cultivar of Chinese cabbage have not been widely studied in Korea, and our study provides valuable information in this regard, as Chinese cabbage is consumed throughout the year in Korea.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.9
• /
• pp.1412-1418
• /
• 2013

The nutritional components of 14 new cultivars of pak choi (Brassica rapa L. ssp. chinensis) from China were analyzed and compared with 4 cultivars of Chinese cabbage (Brassica rapa L. ssp. pekinensis) popular in Korea. Leaves were separated into green parts (GP) and white parts (WP) for the analyses. The moisture and ash content in the 14 new cultivars of pak choi were not significantly different from the currently popular cultivars of Chinese cabbage. In addition, the levels of vitamin C and E were very similar between the two kinds of Brassica rapa. In contrast, the overall mineral content was higher in the new pak choi cultivars. Specifically, minerals important for human health, calcium and magnesium, were significantly greater in pak choi cultivars (calcium GP 2.57, WP 2.04; magnesium GP 0.422, WP 0.301 mg/g fresh weight) compared to currently popular cultivars (calcium GP 0.805, WP 0.477; magnesium GP 0.244, WP 0.101 mg/g fresh weight). Although the content of reducing sugars was similar, cellulose content (which correlates with the hardness of plant tissue) was four times higher in the new pak choi cultivars compared to currently popular cultivars. These results demonstrate that the new pak choi cultivars have superb nutritional benefits for human health and could be a good food source as a daily staple vegetable.

• Preventive Nutrition and Food Science
• /
• v.3 no.3
• /
• pp.277-281
• /
• 1998

There is extensive evidence suggesting the protective role of fruits and vegetables against chemically induced carcinogenesis. We have tested the ability of a representative range of Korean vegetables to act as blocking agents against neoplastic initiation by determining the induction level of quinone reductase , an anticarcinogenci marker enzyme, in hepalclc 7 cells exposed to vegetable extracts. Among thirty vegetables tested, Arcitum lappa(Burdock), Brassica juncea (Mustard leaf), Pteridium aguilinum (Bracken) and Chrysanthemum cornoratium(Crown daisy) caused a significant induction of quinone teductase activity with a limited increase in arylhdrocarbon hydroxylase activity. Combination of crown daisy with burdock had synergistic effect on quinone reductase induction. Quinone reductase-inducing activity was found mostly in hesane and ehtylactate fractions of MeOH extract of crown daisy while it ws not quinone reductase activity in liver, kideny, lung, and small intestine, confirming the presence of potent QR inducer (s) in crown daisy. These sata suggest that some vegetables including crown daisy induced QR merits further investigation as a potential cancer preventive agent in human.

• Korean Journal of Food Science and Technology
• /
• v.22 no.5
• /
• pp.555-561
• /
• 1990

Aromas of sulfur-containing volatiles from two vegetable varieties of Cruciferae Brassica oleracea and the suppression of undesirable sulfurous aromas of cruciferous vegetables by sulfhydryl oxidase of caraway seeds were examined. Aroma components were separated by gas chromatography equipped with a dual flame photometric detector The volatile sulfides produced from cabbage and broccoli varied. in the relative quantities and rates of production. according to the amount of caraway seeds added and incubation time. The amount of methanethiol and dimethyl disulfide in the cabbage and broccoli with caraway seeds was far less than those in the cabbage and broccoli. Removal of methanethiol and dimethyl disulfide was proportional to the amount of caraway seeds added, and was remarkable with 2.5% aqueous slurries of caraway seeds added.

• Food Science and Preservation
• /
• v.19 no.1
• /
• pp.1-6
• /
• 2012

The effect of the packing methods for enhancing the shelf life and improving the postharvest quality of the $tah$ $tasai$ Chinese cabbage baby leaf vegetable was studied during storage. Fresh baby leaf vegetables were packed in four commercial packaging types: (1) a non-perforated bag with a 0.03-mm oriented polypropylene (OPP) film; (2) a perforated bag with 1.0-mm-diameter holes on an OPP film; (3) a 0.40-mm polyethylene terephthalate (PET) container with a hinged lid; and (4) an expanded polystyrene (EPS) tray wrapped with a 0.02-mm polyvinyl chloride (PVC) film. The quality parameters, such as the weight loss, moisture content change, color difference, and appearance of the baby leaf vegetables were investigated. The baby leaf vegetables in the PET container and in the non-perforated OPP film bag showed relatively low weight loss, high moisture content, and good external appearance compared to those in the EPS tray and in the perforated OPP film bag during limited storage periods, at $16^{\circ}C$. The PET container also protected the baby leaf vegetables from physical damage. The study results will enable the selection of a better packaging system for extending the freshness and increasing the market ability of baby leaf vegetables.

• Horticultural Science & Technology
• /
• v.32 no.3
• /
• pp.408-414
• /
• 2014

The antimicrobial and antioxidant activities of different cultivars and parts of broccoli were investigated. The screening of antimicrobial activities for the floret and leaf extracts of 11 cultivars against selected gram positive (Staphylococcus aureus and Listeria monocytogenes) and gram negative bacteria (Escherichia coli O157:H7 and Salmonella enteritidis) were conducted. The AMG cultivar showed the highest antimicrobial activity against S. aureus with the floret and leaf extracts (12.83 and 13.00 mm). Antibacterial activity against L. monocytogenes was strongest with floret extract of NJ cultivar (13.58 mm) and leaf extract of YDR cultivar (13.92 mm). Moreover, the size of inhibition zone against L. monocytogenes was bigger than those of 4 kinds of pathogenic bacteria. Both floret and leaf extracts of Grd cultivar showed the highest antimicrobial activity against E. coli O157: H7, but there was no difference between floret and leaf extracts. Floret extract o f NJ cultivar and leaf extract of NY and 0c cultivars were effective against S. enteritidis whereas leaf extract exhibited better antimicrobial effect than floret extract. These results showed that floret extract of NJ and leaf extract of 0c had the highest antioxidant activity which was 39.90 and 43.64%, respectively. The antioxidant activity of leaf extract was 1.5 times higher than that of floret extract. All cultivars except NJ showed that electron donating ability of leaf extract was higher than that of floret extract.

• Horticultural Science & Technology
• /
• v.32 no.6
• /
• pp.864-871
• /
• 2014

Seed viability is affected by storage conditions and rapid loss of viability in storage is the major cause for low germination. This study was carried out to examine the effect of packaging materials and storage temperature on seed germination rate over 10 years in two species (Capsicum annuum L. and Brassica rapa L. ssp. pekinensis) and determine effective storage conditions for maintaining seed viability. Seeds were packaged in aluminum poly pouches under vacuum, polyethylene bottles, and paper bags containing silica gel and stored under one of two controlled conditions ($15^{\circ}C$, RH 40% or $5^{\circ}C$, RH 30%) or at ambient condition. Seed germination was recorded at 6-month intervals for 10 years. The seeds of both species showed no decline in viability until 6.5 years at 15 or $5^{\circ}C$, irrespective of packaging materials. However, under ambient conditions, the seeds of chili pepper and Chinese cabbage in paper bags lost viability after 4 and 5 years, respectively. By contrast, seeds of both species in vacuum-aluminum poly pouches exhibited a 99% germination rate after 6 years under ambient conditions. Pepper seeds in the vacuum-aluminum poly pouches maintained a 93% germination rate after 10 years in ambient conditions. These results indicated that a special seed storage facility for maintaining viability of chili pepper and Chinese cabbage seed might not be essential and seed testing would not be necessary for 10 years, if chili pepper and Chinese cabbage seeds were packed in ambient/vacuum-aluminum poly pouches or $5^{\circ}C$/vacuum-aluminum poly pouches.

• Horticultural Science & Technology
• /
• v.33 no.3
• /
• pp.303-308
• /
• 2015

The consumption of leaf vegetables has been steadily increasing in Korea. Leaf vegetables are used for "Ssam (vegetable wrap-up), eaf vegetables has been steadily increasing in Korea. Leaf vegetables are used for asoned condiments inside several layers of young vegetable leaves. This study investigated the effect of air temperature on the growth and phytochemical contents of beet (Beta vulgaris L.) and Ssamchoo (Brassica lee L. ssp. namai) grown in a closed-type plant factory system where fluorescent lamps were used as an artificial light source. Seeds of beet and Ssamchoo were sown in a peat-lite germination mix. The roots of 20-day-old seedlings were washed, and the seedlings were planted on a styrofoam board and grown in hydroponic beds for 25 days under fluorescent light. Plants were exposed to one of three different air temperature regimes (20, 25 and $30^{\circ}C$ during the day combined with $18^{\circ}C$ during the night), which were monitored with a sensor at 30 cm above the plant canopy. Increased plant height and leaf area were observed in beet at $25^{\circ}C$ and $30^{\circ}C$ compared to $20^{\circ}C$. For Ssamchoo, the greatest plant height, leaf area, fresh weight and dry weight were obtained at $20^{\circ}C$. Ascorbic acid content of beet and Ssamchoo leaves were highest at $30^{\circ}C$. In beet, total polyphenol and flavonoid contents were higher at $20^{\circ}C$ (42.4, $197.0mg{\cdot}g^{-1}DW$) and $25^{\circ}C$ (46.9, $217.0mg{\cdot}g^{-1}DW$) than $30^{\circ}C$ (22.4, $88.0mg{\cdot}g^{-1}DW$). In Ssamchoo, total polyphenol and flavonoid contents were also higher at $20^{\circ}C$ (79.2, $268.2mg{\cdot}g^{-1}DW$) and $25^{\circ}C$ (66.3, $258.3mg{\cdot}g^{-1}DW$), respectively, than $30^{\circ}C$ (53.7, $134.7mg{\cdot}g^{-1}DW$). Hence, the optimum temperature appears to be $20^{\circ}C$ for growing both beet and Ssamchoo in a closed-type plant factory system with fluorescent light.