Journal Search Engine
Search Advanced Search Adode Reader(link)
Download PDF Export Citaion korean bibliography PMC previewer
ISSN : 1738-7248(Print)
ISSN : 2287-7428(Online)
Korean Journal of Food Preservation Vol.19 No.5 pp.619-625
DOI :

메꽃(Calystegia japonica)의 영양학적 특성

이양숙, 곽창근, 김남우
대구한의대학교 한약자원학과

Nutritional Characteristics of Calystegia japonica

Nam-Woo Kim, Yang-Suk Lee, Chang-Geun Kwak
Department of Herbal Biotechnology, Daegu Haany University, Gyeongsan 712-220, Korea

Abstract

In the present study, the proximate composition, sugar, minerals, total phenolic and flavonoid compounds, andamino acids in Calystegia japonica (C. japonica) were measured to determine if it can be used as a nutritionaland functional material for the development of valuable foods. The mean crude protein, fat, and ash contents ofthe leaves were 5.75, 2.46, and 7.77%, respectively. The soluble-protein contents of the leaves and roots were146.78 and 33.67 mg%, respectively. The reducing-sugar and free-sugar contents of the leaves were 682.70 and166.00 mg%, respectively, and those of the roots were 2,934.89 and 37.70 mg%. The mineral content of the leaveswas 3,122.13 mg%, and that of the roots was 1,540.85 mg%. The three elements Ca, K, and Mg were very richin all their parts, with minerals accounting for 96-99% of their total mineral contents. The total phenolic compoundof the leaves was 3,028.89 mg%, and the total flavonoid compound was 382.67 mg%. The phenolic and flavonoidcompounds in the leaves were more than 7.6 times those in the roots. The free-amino acid levels in the leavesand roots were 2,467.15 and 1,334.81 mg%, respectively. The results of the comparison of the leaves and rootsof C. japonica showed that the leaves had a rich proximate composition consisting of minerals, total phenolicand flavonoid compounds, and amino acid. This suggests that C. japonica leaves are potentially useful sourcesof functional and favorite foods and nutraceuticals.

Introduction

Many current human health problems relate to diets. Micronutrients are involved in numerous biochemical processes and an adequate intake of certain micronutrients relates to the prevention of deficiency disease. Vegetables are valuable sources of useful material including minerals(1). Diets high in vegetables are also linked to decreased risk of disease (diabetes, cancer, etc) and their consumption should be encouraged (2). 

The Calystegia japonica, also known as japanese bindweed of the Convolvulaceae family, is a perennial herb of climbing plant, it is similar to morning glory. C. japonica include traditional medicines that are derived from all parts of the plants, to function as diuretic, fatigue recovery, antipyretic, anitihypertension, blood sugar decline or laxative purpose in chinese and oriental herb medicine. It has been used in traditional medicine to cure diabetes and hypertension. Also C. japonica used for food, as side dish, green vegetable juice, rice cake or soup (3). 

In preliminary studies, the water and ethanol extracts of C. japonica have a higher xanthine oxidase inhibition than ascorbic acid and butylated hydroxyanisole (4), beneficial effects on antioxidation (5). Also Kim et al (6) reported the genetical and morphological character of genus Calystegia, Lee et al. (7) was identified volatile flavor. Schimming et al (8) have been reported the chemotaxonomic significance of glycosidase inhibiting polyhydroxy-nortropanes for the 65 convolvulaceous species. Also Tatsuzawa et al (9) reported the flower anthocyanins of genus Calystegia in Japan 

The aim of the present study in this part was to determine the chemical composition and mineral contents of C. japonica leaves and roots in order to provide more comprehensive nutrient information about them. Furthermore, phenolic compound and flavonoid compound contents of these C. japonica were also investigated in order to evaluate their potential use nutraceuticals and medicines. 

Materials and Methods

Sample preparation

Calystegia japonicawas collected from a local collect in Gyeongsan Gyeongbuk Korea, in May 2007 and identified by NW Kim from the Daegu Haany University. The collecting sample, C. japonica was separated into leaves and roots. Leaves and roots were oven dried at 40℃ for 24 hours using heated-air dryer (DR-0160, Hankwang, Siheung, Korea). The dried leaves and roots were ground to a powder and stored at -70℃ until analyzed. 

Proximate composition

The moisture, crude protein, crude fat and ash contents were determined following the standard Association of Official Analytical Chemists methods (10). Moisture content was determined after attaining constant weight at 105℃. Crude protein was determined by the micro-Kjeldahl procedure; the factor N×6.25 was used to convert nitrogen into crude protein. The crude fat content was obtained by the Soxhlet extraction method, sung diethyl ether. The ash content was determined by a muffle furnace at 550℃, and then the residue was quantitated gravimetrically. Total carbohydrate content was calculated as 100 - % moisture - % protein - % fat - % ash. 

Soluble protein content

The dried C. japonica leaves and roots (10 g) were homogenized and extracted in 10 volumes of distilled water for 30 min, and the extracts were centrifuged at 1,500 rpm for 10 min and supernatant filtered through Whatman No2 filter paper. Total soluble protein was quantified using the method of Lowry et al(11). Briefly, a 2 mL of extract were assayed with 1 mL mixed reagent(A : B = 50 : 1, A ; 2% Na2CO3 in 0.1 N NaOH, B ; 1% C4H4KNaO6 in 0.5% CuSO4 

5H2O) and allowed to react for 10 min in 30℃. And the mixture was mixed 0.1 mL of folin-ciocalteu's phenol reagent and kept at room temperature for 30 min. Then its absorption was read at measured at 750 nm (Shumadzu UV-1201, Kyoto, Japan). Bovine serum albumin (Sigma-Aldrich Co, St Louis, MO, USA) was used as standard to produce the calibration curve. The mean of three readings was used and the soluble protein content was expressed as bovine serum albumin equivalent, in mg% of dry weight. The experiment was repeated three times. 

Reducing and free sugar contents

Reducing sugar was quantified according to the Somogyi method (12). The dried C. japonica (10 g) were extracted with 100 mL distilled water and filtered through Whatman No 2 filter paper. 1 mL of sample extract was added to 1 mL of the Somogyi reagent and boiled for 20 min, after cooling, 1 mL of Nelson reagent plus 5 mL of distilled water were added. The mixture was shaken and absorbance was measured at 520 nm. The reducing sugar content results were expressed as pure D-glucose (Sigma-Aldrich Co, St Louis, MO, USA) equivalent. The experiment was repeated three times. 

For analysis of free sugar was determined using the method of Shim et al(13). The dried C. japonica (1 g) were extracted with distilled water (10 mL) at room temperature for 6 h and then centrifuged at 3,000 rpm for 15 min. The supernatant was filtered with a sep-pak cartridge C18 solid phase extraction cartridge (Waters, Milford, MA, USA) and this residue was then dissolved in water. The extract was determined by using system HPLC (High Performance Liquid Chromatography, Waters 600E controller, Milford, MA USA). The HPLC system was equipped with a Waters 2410 RI detector (Milford, MA, USA) and with a carbohydrate column (4.6×250 mm, 5 mm; Waters, Milford, MA, USA) at column temperature, 35℃. The mobile phase was acetonitrile/deionized water, 75:25 (v/v) at a flow rate of 1.0 mL/min. The results are expressed in mg% of dry weight, calculated by internal normalization of the HPLC peak area. The sugar standards used for identification were purchase from Sigma Chemical Co (St Louis, USA): D-fructose, D-glucose anhydrous, maltose, D-sucrose, D-trehalose and D-xylose. 

Mineral analysis

The mineral content of C. japonica leaves and roots was analyzed using the method of Yun et al (14). Dry sample was digested with a microwave oven decomposition system (Milestone Ethos-1600, Monroe, CT, USA). Sample 0.5 g was weighed and placed in a teflon digestion vessel with 6 mL of concentrated (65%) HNO3 and 1 mL of 30% H2O2. Digests were left to cool and the sample solution was filtered through a membrane filter (pore size 0.45 m), the volume made up to 50 mL with deionized water. For sample was analyzed using inductively coupled plasma optical emission spectrometers (ICP-OES) (IRIS Interpid II XSP, Thermo, MA, USA). The ICP-OES operating conditions: Nebulizer gas flow, 0.5 L/min at 20.1 psi pressure; Auxiliary gas flow, 0.5 L/min; Sample aspiration rate, 1.8 mL/min; Radio frequency (RF) power, 1.15 kW; Integration time, 30 sec; Relax pump time, 5 sec; gas, argon. All samples were measured in triplicate. Lines selected for the determination of the elements are listed in Table 3. 

Total phenolic compound contents

The leaves and roots of C. japonica (10 g) were extracted with 100 mL distilled water, and the supernatant filtered through Whatman No 2 filter paper. It used to determine the content of total phenolic compound using the Folin-Denis method (15). Briefly, the extracts (0.2 mL) were mixed with 1.8 mL of distilled water and 0.2 mL of Folin-ciocalteu's phenol reagent (Junsei Chemical Co, Tokyo, Japan) and allowed to react for 3 min, after which 0.4 mL of saturated Na2Co3 solution was added. The mixture was kept at room temperature for 1 hr and then its absorbance was measured at 725 nm (Shimadzu U-1201, Kyoto, Japan). Tannic acid(Sigma-Aldrich Co, St Louis, MO, USA) was used as a standard for preparing of the calibration curve ranging 1~ 1,000 g/mL assay solution. 

Total flavonoid compound content

The total flavonoid compound contents were measured by the method of Nieva Moreno et al(16). The dried C. japonica leaves and roots (5 g) was extracted with 100 mL of 80% ethanol and the supernatant filtered through Whatman No 2 filter paper. An aliquot of 0.5 mL was mixed with 10% aluminum nitrate (0.1 mL), 1 M potassium acetate 0.1 mL and added 80% ethanol (4.3 mL). The mixture was kept at 25oC for 40 min, and then its absorbance was measured at 415 nm. Total flavonoid concentration was calculated using quercetin as a standard (Sigma-Aldrich Co, St Louis, MO, USA) for preparing of the calibration curve ranging 1~1,000 g/mL assay solution. 

Free amino acid and amino acid derivatives analysis

The dried C. japonica leaves and roots (1 g) was extracted with 100 mL distilled water for 2 hours and filtered through 0.45 m filter. The extract was analyzed by using automatic amino acid analyzer (Pharmacia LKB Biochrom Ltd, Cambridge, UK) with analyzer column (Lithium high resolution). The operating conditions were as follows: column temperature, 35℃∼80℃: reaction temperature, 135℃; mobile phase, ninhydrin 25 mL/hr; flow rate 20 mL/hr. Identification and quantification of free amino acids and amino acid derivatives were achieved by comparing the retention times of the peaks with those standards.

Statistical analysis

C. japonica leaves and roots data are expressed as mean ± SD of at least three separate experiments. Statistical analyses were performed by one-way analysis of variance (ANOVA) followed by Duncan's multiple range tests using version 15.0 for windows (Statistical Package for the Social Science, SPSS INC, Chicago, IL, USA). Probability values <0.01 were student's t-test, significantly different compared between two trial groups. 

Result and Discussion

Proximate composition

C. japonica. were divided into two different parts: leaves and roots and the proximate compositions in these two parts were determined. As shown in Table 1, the carbohydrate ranged from 71.47% of dry weight in leaves and 75.35% in roots. The contents of the moisture contained 12.55% and 11.18 %, respectively. Crude ash content varied between 7.77% in leaves and 5.83% in roots. The content of protein from leaves was 5.75% and roots was 5.51%. Crude fat content were 2.46% in leaves and 2.13% in roots. The most abundant component is carbohydrate, crude ash is the second  abundant component. The carbohydrate contents of roots was higher than leaves, but other components in roots were contained lower than leaves.

Table 1. Proximate composition of leaves and root parts from C. japonica

Soluble protein, reducing sugar and free sugar contents

Table 2 shows the soluble protein, reducing sugar contents and free sugar composition in C. japonica leaves and roots. The soluble contents of the leaves were 146.78 mg%, which is significantly lower (p<0.01) than that observed in the roots (33.67 mg%). The content of reducing sugar in leaves was 682.70 mg%, the total amount of free sugar was 166.00 mg% including 165.45 mg% glucose and 0.55 mg% maltose. The reducing sugar of roots (2,934.89 mg%) were about 4.3 times greater that of leaves, free sugar of roots (37.70 mg%) including 36.75 mg% glucose and 0.95 maltose were lower than leaves. Total sugar in roots were 3.5 times higher than leaves (p<0.01). Free sugar of leaves and roots presented glucose as main sugars. Glucose was the over 97% as free sugar. This is in agreement with the results reported for the Syneilesis palmata (17). Also Kim et al (18) reported that the free sugar of Acrorus calamusleaf and root showed 990 mg% and 1,940 mg%, respectively. Among these, leaf and root glucose were 610 mg% and 1,080 mg%, fructose were 380 mg% and 860 mg%, respectively, in which glucose accounted for almost the whole of the free sugar determined. similar observations have been made in other plants (18). 

Table 2. Contents of soluble protein, reducing sugar and free sugar of leaves and root parts from C. japonica

Mineral content

The mineral contents of herbal plant and food are gaining importance because of toxicological as well as their nutritional viewpoints. Dietary intake is considered to be the major supplier of these elements of the body (19). In this study, the mineral composition of C. japonica leaves and roots, performed by ICP-OES, are displayed in Table 3. The mineral composition and contents of C. japonica leaves and root were difference, with the detected total 12 minerals. The total mineral contents of leaves were 3,122.13 mg% and roots were 1,540 mg%, the leaves were twice more than roots. The three elements Ca, K, and Mg which account for 96% to 99% of total mineral contents, were very rich in all parts. Ca content in leaves were the highest (1,925.20 mg%), comprising more than 61% of the total mineral content, followed by 732.87 mg% for K. And the K in roots (1,282.13 mg%) were more than 83% of the roots total mineral content, and followed by Ca (122.83 mg%). The Co, Ge and Cr were not detected in the C. japonica. Ca and Mg are the major component of bone and assists in teeth development (20), helping immune system. Especially Mg is a necessary nutrient for the normalization of the function of various endogenous enzymes, for helping the energy generation and for the normalization of the blood circulation. K is effective mineral for diuretic effect. In sum, C. japonica can be effective and useful herbal materials as metabolic and physiological activity

Table 3. Mineral composition and contents of leaves and roots of C. japonica

Total phenolic and flavonoid compound contents

As phenolic compounds have been shown to possess strong antioxidant activity, and flavonoids are one of the most diverse and widespread group of natural phenolic compounds, flavonoids are likely to be the most important natural polyphenols (21). Especially phenolic compounds have strong antioxidative activity (22). Thus, the phenolic compound content including flavonoid compound content could be used as an important indicator of antioxidant capacity (23). Antioxidant play an important role in decreasing DNA damage, diminishing lipid peroxidation, maintaining immune function, and inhibiting malignant transformation or proliferation in vitro, which are thought to prevent some diseases, cancer, diabetes, hypertension, heart disease and age related degenerative conditions. The total phenolic and flavonoid compound contents of the leaves and roots from C. japonica are shown in Table 4. The leaves had a higher phenolic and flavonoid compound contents than roots. The phenolic compound contents of leaves and roots were 3,028.89 mg% and 381.11 mg%, and the flavonoid compound contents were 382.67 mg% and 50.49 mg%, respectively. Kim et al, (2004) reported that the phenolic compound contents of Korean ginseng and Polydonatirhizoma showed 397 mg% and 262 mg%, the flavonoid compound contents were 591 mg% and 51 mg%, respectively. This C. japonica results were higher phenolic compound than the Kim et al, (24) reported. 

Table 4. Contents of the total phenolic and flavonoid compound from leaves and root parts from C. japonica

Free amino acid and amino acid derivatives analysis

The amino acid and derivatives composition of leaves and roots of C. japonica is shown in Table 5. The results showed that leaves and roots contained 17 known amino acids, including all of the essential amino acids and 15 known amino acid derivatives. The leaves and roots amino acid contents were 2,467.15 mg% and 1,334.81 mg%, respectively. The amino acid derivatives were 1,515.10 mg% (leaves) and 1,140.92 mg% (roots). The leaves amino acid and derivatives contents were higher than roots. The leaves had higher contents of glutamic acid, glycine, alanine, tyrosine and essential amino acids than that of roots. The roots was higher contents of aspartic acid, serine, histidine, arginine and proline. The percentage of essential amino acids in total amino acids was 45.11% (1,112.96 mg%) in leaves and 32.92% (439.44 mg%) in roots. The percentage of savoury amino acids, aspartic acid and glutamic acid, to total amino acid in roots were as high as 28.11% and 13.87%, the sweet (alanine) and savoury (glutamic acid) amino acid to total amino acid in leaves were as high as 20.40% and 17.52%, respectively. The percentage of γ-aminoisobutyric acid in total amino acid derivatives was 49.25% in leaves. the roots were including α-aminoadipic (33.48%) acid in total amino acid derivatives. 

Table 5. Contents of the free amino acid and amino acid derivatives of aerial and root parts from C. japonica

Conclusion

According to the results of the present study, we found that C. japonica leaves are higher than roots, as protein, minerals, total phenolic compounds, flavonoid compound contents, free amino acid and amino acid derivatives. This suggests that C. japonica leaves are a good source of nutrient and micronutrients for health, C. japonica is a potentially useful of resource for the functional and favorite food and nutraceutical. 

01 김남우(최종).pdf264.6KB

Reference

1.1. Milton K (2003) Micronutrient intakes of wild primates: are humans different? Comparative Biochemistry and Physiology, 136, 47-59
2.2. Leterme P, Munoz LC (2002) Factors influencing pulse consumption in Latin America. British J Nutrition, 88, S251-S254
3.3. Park CH (2004) Medicinal plants of korea. Shinil Books Co., Seoul Korea, p 1110
4.4. Choi BD, Jeon HS, Lee YS, Kim NW (2010) Analysis of the contents and physiological activities of Calystegia japonica leaf extracts. Korean J Food Sci Technol, 42, 250-255
5.5. Lee YS, Choi BD, Joo EY, Kim NW (2009) Physiological activities of roots extracts from Calystegia japonica. J Exp Biomed Sci, 15, 335-342
6.6. Kim YS, Choi BY (1983) Chromosome number, morphological and anatomical study on Calystegia in Korea. Kor J Plant Tax, 13, 89-107
7.7. Lee MS, Choi HS (1994) Volatile flavor components in various edible portions of Calystegia japonica (THUNB) CHOIS. Korean J Food Sci Technol, 26, 359-364
8.8. Schimming T, Tofern B, Mann P, Richter A, Jenett-Siems K, Drager d, Asano N, Gupta MP, Correa MD, Eich E. (1998) Distribution and taxonomic significance of calystegines in the Convolvulaceae. Phytochem, 49, 1989-1995.
9.9. Tatsuzawa F, Mikanagi Y, Saito N (2004) Flower antocyanins of Calystegia in Japan. Biochem Sytem Ecol, 32, 1235-1238.
10.10. AOAC (2005) Official method of analysis. 18th ed., Association of official analytical chemists. Washington DC USA, 45, 21-22
11.11. Lowry OH, Roserbrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the folin phenol reagent. J Biol Chem, 193, 265-275
12.12. Nelson N (1944) A photometric adaption of the somogyi method for determination of glucose. J Biol Chem, 153, 375-381
13.13. Shim KH, Sung NK, Choi JS, Kang KS (1989) Changes in major components of japanese apricot during ripening. J Korean Soc Food Nutr, 18, 101-108
14.14. Yun SI, Choi WJ, Choi YD, Lee SH, Yoo SH, Lee EH Ro HM (2003) Distribution of heavy metals in soils of Shihwa tidal freshwater marshes. Korean J Ecol, 26, 65-70
15.15. Swain T, Hillis WE, Ortega M (1959) Phenolic constituents of Ptunus domestica I. Quantitative analysis of phenolic constituents. J Sci Food Agric, 10, 83-88
16.16. Nieva Moreno MI, Isla MI, Sampietro AR, Vattuone MA (2000) Comparison of the free radical-scavenging activity of propolis from several regions of Argentina. J Ethnopharmacol, 71, 109-114
17.17. Lee YS, Seo SJ, Kim NW (2009) Analysis of the general components of Syneilesis palmata Maxim. Korean J Food Preserv, 16, 412-418
18.18. Kim HJ, Kim SW, Shin CS (2000) Analysis of chemical composition in leaf and root of Acrorus calamus L. Korean J Food Sci Technol, 32, 37-41
19.19. Demirozu B, Sokmen M, Ucak A, Yilmaz H, Gulderen Ş (2002) Variation of copper, iron and zinc levels in pekmez products. Bul Environ Contamin Toxicol, 69, 330-334
20.20. Brody T (1994) Nutritional biochemistry San diego. CA, Academic Press, p 555-556
21.21. Cai Y, Luo, Q, Su M, Corke H (2004) Antioxidant activity and phenolic compounds of 112 Chinese medicinal plants associated with anticancer. Life Sci, 74, 2157-2184
22.22. Vinson JA, Pinch J, Bose P (2001) Determination of quantify and quality of polyphenol antioxidants in foods and beverages. Method Enzymol, 335, 103-114
23.23. Duan X, Wu G, Jiang Y (2007) Evaluation of the antioxidant properties of litchi fruit phenolics in relation to pericarp browning prevention. Molecules, 12, 759-771
24.24. Kim EY, Baik IH, Kim JH, Kim SR, Rhyu MR (2004) Screening of the antioxidant of some medicinal plants. Korean J Food Sci Technol 36, 333-338