• The Korean Journal of Community Living Science
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• v.26 no.2
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• pp.405-414
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• 2015

This study examines the effects of purple Kohlrabi fresh and peel ethanol extracts on the antioxidative activity and antiproliferation of human cancer cells (Hep G2 human liver, HCT-116 human colon, and A549 human lung cancer cells.) The total flavonoid and anthocyanin content of purple Kohlrabi ethanol extracts were much greater in the peel than in the flesh. The DPPH radical scavenging activity and antioxidative index of purple Kohlrabi peel extracts were similar to those of the BHA and the BHT. Antiproliferation effects of purple Kohlrabi peel extracts on human cancer cells (Hep G2, HCT-116, and A549) strengthened in a dose-dependent manner. In particular, the antiproliferation activity of purple Kohlrabi peel extracts exceeded 40% in colon cancer cells. These results indicate that the purple Kohlrabi peel may contain bioactive compounds such as flavonoids as well as anthocyanin and that these compounds may facilitate cancer prevention.

• Journal of Applied Biological Chemistry
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• v.57 no.4
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• pp.353-358
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• 2014

Antioxidant activities of ethanol and water extracts of flesh, leaves, and peels of green and purple Kohlrabi were measured by rancimat method, total phenolic compound (TPC), DPPH radical scavenging effect, chelating effect, and reducing power analysis. The highest TPC was observed in ethanol extract from green peel and water extract from purple leaf with 12.00 and 11.70 mg/g of dry sample, respectively. The ethanol extracts from purple Kohlrabi leaf and peel exhibited strong DPPH radical scavenging effects with reducing power while water extracts from purple Kohlrabi leaf and peel also showed strong DPPH radical scavenging with chelating effects. Antioxidant index of ethanol and water extracts from green and purple Kohlrabi measured by rancimat was lower than butylated hydroxytoluene. These results suggest that extracts from purple Kohlrabi leaf and peel exhibited higher antioxidant activities than those of green Kohlrabi, and can be potentially used as proper natural antioxidants.

• Food Science and Preservation
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• v.21 no.6
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• pp.824-830
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• 2014

In this study, the quality characteristics of cookies with added purple kohlrabi (Brassica oleracea var. gongylodes) powder were investigated and analyzed through chemical and sensory evaluation. Samples were prepared with different levels (0, 1, 3, and 5%) of freeze-dried kohlrabi powder. The addition of Kolarbi powder decreased the moisture and fat contents, but the ash content was significantly increased (p<0.05). The pH and density of the cookie dough decreased significantly with the increasing levels of kohlrabi powder added (p<0.05). The spread ratio of the cookies generally decreased as more kohlrabi powder was added, but the decrease was not statistically significant. The hardness of the cookies increased significantly, however, with the increasing levels of kohlrabi powder added (p<0.05). The Hunter's color L, a, and b values significantly decreased with increasing kohlrabi powder compared to those of the control (p<0.05). In the sensory evaluation, the cookies to which 3 and 5% kohlrabi powder were added showed remarkably higher values for color, taste and appearance. These results suggest that purple kohlrabi powder is a good ingredient for improving the sensory and quality characteristics of cookies.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.601-608
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• 2014

In this study, we investigated the antioxidant activity of green kohlrabi juice (GKJ) and purple kohlrabi juice (PKJ) using various in vitro methods. The results of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities, ferric ion reducing antioxidant power (FRAP), reducing power, and nitrite scavenging activities showed that GKJ possessed higher antioxidant activity than PKJ. Green kohlrabi powder (GKJP) and purple kohlrabi powder (PKJP) inhibited hydrogen peroxide-induced cell death in human dermal fibroblasts. In addition, GKJP and PKJP suppressed intracellular reactive oxygen species (ROS) production induced by hydrogen peroxide in human dermal fibroblasts. These results suggest that green and purple kohlrabi juices are potential natural sources of antioxidants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1994-2003
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• 2013

This study is performed to evaluate the effects of purple Kohlrabi addition on the quality properties and stability characteristics of hamburger patties during storage. The patties were prepared by adding 0% (N), 3.3% (K1), 6.6% (K2), and 10% (K3) of chopped purple Kohlrabi. Each patty was tested in triplicate and assigned to one of the four storage periods: 0, 5, 10, or 15 days. Addition of Kohlrabi decreased the protein and lipid contents, however, the ash and moisture contents were significantly increased. The total amino acid contents of N, K1, K2, and K3 were $15.34{\pm}1.02$, $14.57{\pm}1.28$, $15.10{\pm}1.17$, and $16.70{\pm}1.23$ mg/100 g, respectively. Palmitic acid was the most abundant among the saturated fatty acids, while oleic acid was the most abundant unsaturated fatty acids among the four groups. The water holding capacity value and cooking loss were not significantly different among the patties. In the textural characteristics, the addition of Kohlrabi increased the cohesiveness and chewiness values, but did not affect the hardness and springiness values of the patties. In the sensory evaluation, an addition of 10% Kohlrabi had the best score in color, flavor, and total acceptability. The pH of the patties decreased longer period storage; however, the total microbial counts, thiobarbituric acid (TBA) value and volatile basic nitrogen (VBN) content increased during storage. The TBA value and VBN content of the patties containing 10% Kohlrabi were lower than those of the N. Kohlrabi addition decreased the b (yellowness) and a (redness) values, and did not affect the L (lightness) value. Thus, this result suggests that adding Kohlrabi of 10% can be applied to patties for its functionality.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.297-300
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• 2017

Plant factory can control artificially the environments for crop cultivation, so they can produce high quality agricultural products all year round. This study was carried to select suitable kohlrabi cultivar for hydroponics in a closed-type plant factory system. We used three cultivars of red kohlrabi, 'Asac kohl', 'Kolibri', and 'Purple king' as plant materials. The artificial light source was LED light, light intensity and photoperiod were $249{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and 12/12 hours (day/night period), respectively. Hydroponic cultivation type was used circulating deep flow technique. At 43 days after transplanting, fresh weight of whole plant and tuber and leaf area were not significantly different among cultivars. Shoot dry weight and tuber dry weight were highest in 'Asac kohl' cultivar, and number of leaves was highest in 'Purple king' cultivar. Sugar content and yield were highest in 'Asac kohl' cultivar. Considering the growth and marketable yields, 'Asac kohl' was the optimal kohlrabi cultivar for hydroponic cultivation in a closed-type plant factory system.