Jeonghae Rho

The Changes of Ginsenoside Patterns in Red Ginseng Processed by Organic Acid Impregnation Pretreatment

In order to enhance bioactive functionalities of ginseng, an acid impregnation processing was applied as a pre-treatment in producing red ginseng. Acid impregnation studies were conducted, and acids (ascorbic, malic, and citric acid) were selected. The optimal concentration of each acid was investigated in this study in terms of ginsenoside contents. The most concerned ginsenoside, Rg3 was increased by ascorbic, malic, and citric acid pre-treated red ginseng up to 1 M acid concentration. In the case of ascorbic acid pre-treated red ginseng, Rg2 concentration was increased depending on acid concentrations. Citric acid pre-treatment enhanced Rg2, Rg3, and Rh1+Rh2 formation in red ginseng. Therefore, ginsenoside patterns in red ginseng could be changed by acid impregnation pre-treatment depending on acid concentration and acid types. This research is expected to contribute to the development of the ginseng industry via new red ginseng products with selective and intensified functionality.

Morphological Characteristics of Korean Dried Ginseng Products

The purpose of this study was to determine a standard quality characteristic through the evaluation and statistical analysis of the morphological characteristics of dried ginseng (white ginseng) products. Samples of 4-year-old 30 and 50 piece grade curved ginseng and 5-year-old 25 and 15 piece grade straight ginseng products were collected from a market, with 5 to 10 packs of each product being collected annually over a 5-year period (2006-2010). Morphological characteristics, such as weight, length, diameter, and surface color, were measured and statistically analyzed to present a standard quality characteristic value using mean±3SD, a range that excluded outlier. The 4-year-old curved ginseng samples of 50 and 30 piece grade were 4.80 to 6.12 cm and 5.28 to 7.60 cm long, 0.22 to 1.70 cm and 0.21 to 2.07 cm wide, and weighed 5.28 to 7.40 g and 8.62 to 12.26 g, respectively. The 5-year-old straight ginseng samples of 25 and 15 piece grade were 9.66 to 15.47 cm and 10.66 to 16.80 cm long, 1.32 to 1.94 cm and 1.48 to 2.43 cm wide, and weighed 9.18 to 16.40 g and 15.89 to 24.82 g, respectively. The surface color of the different piece grades in the same type of dried ginseng product was similar, whereas the straight ginseng demonstrated a lower level of brightness, but the relative redness and yellowness were of higher levels, than that of curved ginseng.

Characteristics of Acid Pre-treated Red Ginseng and Its Decoction

This study was conducted to produce a new red ginseng by steaming ginseng using a new pre-treatment method, so as to develop ginseng products with improved flavor and thereby expand ginsengs consumer base. The color parameters (Hunter value), free sugar contents, and ginsenoside contents of the powder from the dried red ginseng, and the sensory test of the semi-dried red ginseng and the decoction from the dried red ginseng, were measured to investigate the effect of acid (ascorbic acid or citric acid) impregnation pre-treatment on red ginseng. The powder from the acid-pretreated red ginseng became lighter and more yellow than the red ginseng that was not pre-treated, but the redness (avalue) of the powder from the acid-pre-treated red ginseng increased. The ginsenoside contents of Rg₂+Rh₁ and Rg₃ increased with the acid treatment. There was a significant difference in the color and sweetness of the semi-dried acidtreated and non-treated red ginsengs in the sensory test. As the results of the sensory test were expressed in the hedonic scale, however, there were significant differences in the degrees of bitterness, astringency, sourness, odor, and color of the red ginseng decollation. Especially, the acid-treated red ginseng extract tasted less bitter, which shows the potential of new red ginseng products with improved ginseng flavor.

Characteristic Changes of Galgeuntang Fermented with Lactic Acid Bacteria

The possible application of Lactobacillus spp. as a functional starter culture to ferment galgeuntang (GT) and to produce bioactive isoflavone (daidzein) was investigated. Lactobacillus casei KFRI 127, L. plantarum KFRI 144, L. bulgaricus KFRI 344 were used for GT fermentation. Acid development and quantification of isoflavones using high-performance liquid chromatography were performed after fermentation at 37oC for 48 h. All the tested Lactobacillus spp. lowered pH to about 3.8 in 48 h and L. plantarum KFRI 144 exhibited 89.9% hydrolysis rate of daidzin (79.1-8.0 μg/mL) during fermentation. The content of daidzein in GT fermented with L. plantarum KFRI 144 was increased by 6.6-fold (3.6-23.9 μg/mL). These results demonstrate that L. plantarum KFRI 144 has potential as functional starter culture for manufacturing fermented GT with higher isoflavone bioavailability.

Effect of germinated grain flours on physicochemical characteristics of rice cakes, Seolgitteok

Minor grains and their germinated shoots such as buckwheat, Jobs tears, and mungbean have diverse bioactive functionalities. In this study, the flours of grains and germinated grains were added to Korean rice cakes, known as Seolgitteok, and the effects on properties such as starch gelatinization and retrogradation were examined. The dietary fiber content, blue value index, amylogram, texture properties and sensory evaluation of Seolgitteok were also investigated. Rice flour amylogram results showed that addition of buckwheat, germinated Job’s tears, and mungbean decreased starch setback, and that addition of buckwheat decreased consistency, which are related to slowed retrogradation. Buckwheat, especially when germinated, delayed starch retrogradation, which is one of the main drawbacks of rice cakes. Seolgitteok with added germinated buckwheat possessed preferable sensory qualities.