5

[J. Jpn. Soc. Starch Sci., Vol. 30, No. 1, p. 5-.12 (1983)]

Some Properties of Starches of Job's Tearst•õ

Yoshiko IKAWA,* Mi Young KANG,** Masako ASAOKA,**

Sadao SAKAMOTO*** and Hidetsugu FUWA**,•õ•õ

*Department of Home Economics , Fukuoka University of Education(729, Akama, Munakata 811-41, Japan)

**Department of Food and Nutrition , Osaka City University(3-3-138, Sugimoto, Sumiyoshi-ku, Osaka 558, Japan)

***Plant Germ plasm Institute , Faculty of Agriculture, Kyoto University

(1, Nakajo, Mozume, Muko, Kyoto 617, Japan)

(Received August 9, 1982)

Distribution of isoamylase-debranched starch components, X-ray diffraction patterns, gelatinization characteristics by photopastegraphy and differential scanning calorimetry, and starch-granule susceptibility to amylases were investigated for starches of Job's tears (hatomugi, Coix lacryma jobi L. mayuen (Roman) Stapf. and juzudama, Coix lacryma-jobi L.). Starches were prepared from seeds of hatomugi and juzudama cultivated or collected in Japan and Korea. There were two types of grain among hatomugi open-cultivated at Nakazato and Okayama. Therefore, the waxy-type grains were separated from the nonwaxy-type ones by iodine staining of endosperms. The results obtained were as follows; (1) Fundamentally, endosperms of hatomugi had waxy-type starch and those of juzudama had nonwaxy-type starch. Starch of nonwaxy-type Nakazato was resemble to that of juzudama. (2) Starches of hatomugi and juzudama were close resemblance in distribution of starch components and gelatinization characteristics to those of waxy and nonwaxy-type of maize, respectively. (3) All starches had A-type pattern of X-ray diffractograms. (4) Starch-

granules of juzudama showed a wide range of susceptibility values to amylases. The phenomenon in-dicated that the starches had a wider range of characteristics than those of domesticated plants.

(5) There was a great resemblance in properties of endosperm starches between Job's tears and maize.

Juzudama (Coix lacryma jcbi L.), one of Job's tears, belongs to the same family (Gramineae) and tribe (Maydeae) as those of maize (Zea mays L.) on botanical classification. In the case of hatomugi, the other Job's tears, there are two opinions in the classification, which have not been settled yet. One is that hatomugi (Coix lacryma jobi L. ma yuen (Roman.) Stapf.) is a variety of juzudama, and the other is that hatomugi belongs to Coix ma-yuen Roman., and a different species from

juzudama.l) But generally, the former opinion has been more acceptable. Hatomugi was domesticated first in the India

Burma area for shifting cultivation before upland rice was established.2,3) However, hatomugi was accepted as a medicinal herb rather than foods in Japan. Their seeds had several pharmacological effects for some diseases and was also used for nourishing food.4) Juzudama has been believed to be native to Asia and was utilized for similar

purpose to hatomugi.4) Thus, hatomugi and juzudama have been considered as materials of the herb medicine or foods for keeping health. Recently, both plants have been brought to attention as forage crops5,6) and materials of food industry7) because they are able to grow on lowland fields in

place of paddy rice. Grains (hulled seeds) of Job's tears contain 50-

60% of carbohydrates,8,9) of which starch is the main component. Several reports suggested that

•õ Dedicated to the memory of the late Professor Dexter

French.

•õ•õ To whom correspondences should be addressed.

6 J. Jpn. Soc. Starch Sc., Vol. 30, No. 1 (1983)

endosperm starch of juzudama was nonwaxy-type and that of hatomugi was waxy-type.10) Several cereals; rice, barley, foxtail millet, maize, proso millet and sorghum, have both waxy mutants and their normal or nonwaxy counterparts in each one of the same species. Kempton reported that he found nonwaxy-type grains among the seeds classified as ma-yuen.ll) It is very interesting point in connection with botanical classification whether hatomugi has waxy mutant only. There are only few reports on starches of Job's tears in these years. Sato and Miyata reported

properties of starches from hatomugi, juzudama and hybrid between hatomugi and juzudama.1,12) But there is no work in which properties of several kinds of hatomugi and juzudama starches were investigated at the same time. We already re-

ported some properties of starches from several cereals which have both waxy and nonwaxy endosperms in each one of the species.13,14) In this study, fundamental properties of starches are investigated for several kinds of hatomugi and

juzudama cultivated or collected in Japan and Korea.

MATERIALS AND METHODS

Seeds. Places of cultivation or collection and sample numbers of the seeds which were used for

preparation of starch-granules are shown in Table 1. Seeds of Okayama, Nakazato and Toyama of hatomugi and those of Kanagawa, Tokyo and Miyazaki of juzudama were cultivated or collected in Japan, and others were collected in Korea.

There were two types of grain in Okayama and Nakazato, one was stained reddish-brown with io-dine solution and the other blue. Therefore, the waxy-type grains were separated from the non-waxy-type ones by iodine staining of endosperms. Seeds of Okayama and Nakazato had 2.4% and 40.5 % of nonwaxy-type, respectively. Then the waxy-type grains of Okayama and Nakazato, and the nonwaxy-type grains of Nakazato were used for preparation of starch-granules. The samples were named as Okayama, Nakazato (waxy) and Nakazato (nonwaxy), and others were listed by sample numbers as shown in Table 1. Symbols of large letters (A-F) were given to hatomugi and those of small letters (a-f) to juzudama (see Table 1), and these symbols were used for Figs. 1-7.

Table 1. Places of collection and sample numbers

of Job's tears.

Preparation of starch-granules. Modified Watson's method15) was used for preparation of starch-granules. Briefly, hulled seeds were soaked over-night in 0.2% potassium pyrosulfite solution

adjusted in pH 5 with potassium hydroxide. The

grains were ground in a motar and a pestle, and passed through nylon cloth screen, then 200 or 300 meshed sieves. Cold sodium hydroxide solution adjusted in pH 11 (approx. 0.1 % NaOH) was added to the sieved granules and the mixture was kept in a cold room over-night. After the granules were washed with cold water several times,

protein was removed from the granules shaking with isoamylalcohol or toluene. Then the gran-ules were washed with water several times and ethanol, and dried at room temperature. The recovery of starch-granules based on weight of hulled seeds were 36.0-49.2%, and the starch-

granules contained not more than 1 % of protein by Lowry's method.16) It was observed that the starch-granules were polyhedral or round in shape and had various size (6-29um) by scanning electron microscopy. Absorption spectra of starch-iodine complexes. Absorption curves of starch-iodine complexes were recorded by the method reported previously.13)

Gel filtration of isoamylase-debranched starches. Procedure for debranching of starches by Pseu-domonas isoamylase and fractionation of de-branched starches on a Sephadex G-75 column were described earlier.l7) Total carbohydrate con-tents of each tube were determined by the phenol-sulfuric acid method,18) and reducing ends of carbohydrates were measured with a modified Park-Johnson's method reported by Hizukuri and Takeda.19)

X-ray diffractometry. X-ray diffraction dia-

grams were recorded by the method reported

Properties of Job's Tears Starch 7

previously.13) Photopastegraphy and differential scanning calorimetry. Photopastegrams and DSC thermograms of the starches recorded as reported previously.13) Degradation of starch-granules by amylases. These methods and source of amylases were re-

ported previously.20)

RESULTS AND DISCUSSION

Ahsonrptinn spectra of starch-iodine complexes

Figure 1 shows absorption curves of starch-

iodine complexes from several Job's tears and non-

waxy maize starch. Wavelengths at maximum

absorbance (ămax) and absorption intensities at

680 nm, that is "blue value" (BV), are shown in

Table 2.

Iodine-absorption curves of hatomugi starches except Nakazato (nonwaxy) were drown between C, 79519 and B, 79517 curves. In juzudama starches, curves were between b, 76502 and d, 77509-2 curves (Fig. 1). Since ămax of absorption curves were at 520-530

nm and BY showed low level for hatomugi except

Nakazato (nonwaxy), these results suggested that

the starches were waxy-type (Table 2). On the

other hand, juzudama starches had 580-590 nm of

ă max and 0.36-0.40 of BY (Table 2). These values

indicated that the starches were nonwaxy-type

same as nonwaxy maize starch.

There was little difference in ămax of iodine

stainning curves between Nakazato (nonwaxy) and

juzudama starches. But absorption intensity of

Nakazato (nonwaxy) was lower at each wavelength,

and the starch might be a different type.

Elution profiles of debranched starches by gel fil-tration

Elution patterns of isoamylase-debranched starches of several Job's tears are shown in Fig. 2. Two peaks appeared for the waxy-type starches

(Fig. 2A, 2E) and three peaks for the nonwaxy-type starches (Fig. 2F, 2b, 2d). The first peak, fraction I

(Fr. I), comprised higher molecular-weight materials and regarded as amylose because absorption maxima of the iodine-carbohydrate complexes of the fraction were over 620 nm. The second and third peaks, fraction II (Fr. II) and fraction III

(Fr. III), arose from amylopectin because chainlengths of apices of their peaks were about 40 and

Fig. 1. Absorption spectra of starch-iodine com

plexes of several starches of Job's tears and maize.

B, 79517; C, 79519; D, Okayama; F, Nakazato

(nonwaxy); b, 76502; d, 77509-2; n, nonwaxy maize.

Table 2. Absorption maxima (2max) and blue values of iodine complexes of Job's tears

starches.

12-16, respectively. T able 3 represents contents of each fraction,

ratios of Fr. III to Fr. II (Fr. Ill/Fr. II) and average chain-lengths (CL) of each apices of Frs. II and III of all samples. Hatomugi starches except Nakazato (nonwaxy) had 0 % of Fr. I and 3-4 of Fr. III/Fr. IL These values were similar

8 J. Jpn. Soc. Starch Sc., Vol . 30, No. 1(1983)

to those of other waxy-type starches.14) It is

concluded that these hatomugi starches are waxy-

type by the results. Hatomugi starches of #79517

and #79519 cultivated in Korea had somewhat

higher contents of intermediate fraction. But con

tents of other fractions were resemble to those of

hatomugi cultivated in Japan, and there was sta

tistically insignificant difference for CL each other.

Starches of juzudama and Nakazato (nonwaxy)

had 22-26% of Fr. I, no more than 5 % of inter-

mediate fraction and 3.4-3.8 of Fr. ‡V/Fr. ‡U

(Table 3). These results were similar to those of

nonwaxy maize,21) and indicated that these starches

were nonwaxy-type.

X-ray diffractograms X-ray diffraction diagrams of hatomugi starches

are shown in Fig. 3 and those of juzudama starches in Fig. 4. These patterns indicated that starches of Job's tears had A-type crystalline structure according to Katz's classification.22) Diagrams of #79517, #79519 and #79514 (data were not shown here) were also A-type structure.

Photopastegrams of starches Photopastegrams obtained from several starches

are shown in Figs. 5 and 6. Concentrations of the starch suspension were 0.2 % for Fig. 5 and 0.1 % for Fig. 6. After one-step alterations, de-crease of transmittance were obserbed in waxy-type

Fig. 2. Elution patterns on a Sephadex G-75 column of isoamylase-debranched starches of Job's tears.

H, Intermediate fraction; A, 76505; E, Nakazato

(waxy); F, Nakazato (nonwaxy); b, 76502; d, 77509-2.

Table 3. Summary of some properties of isoamylase-debranched components of starches of Job's tears.

Each fraction (Fr.) was divided according to ƒÉmax of iodine-carbohydrate complexes as follows: Fr. I, ƒÉmax•†

620nm; Intermediate Fr., 620 nm>ƒÉmax•†600 nm; Fr. II, 600 nm>ƒÉmax•†540 nm; Fr. ‡V, 540 nm>ƒÉmax.

Properties of Job's Tears Starch 9

Fig. 3. X-ray diffractograms of starches of hatomugi.

A, 76505; D, Okayama; E, Nakazato (waxy); F, Nakazato (nonwaxy).

Fig. 4. X-ray diffractograms of starches of juzudama.

a,76501; b, 76502; c, 76503; d, 77509-2; e, 79513.

hatomugi (Figs. SD, SE, 6A) as shown for those of waxy maize and rice.23) Juzudama and Nakazato (nonwaxy) showed typical two-step gelatinization curves (Figs. SF, 6a-6e) as shown in nonwaxy-type cereal starches.23) Initiation tempera-

Fig. 5. Photopastegrams of several starches of Job's tears.

D, Okayama; E, Nakazato (waxy); F, Nakazato

(nonwaxy). Concentrations of the starch sus-pension were 0.2%.

Fig. 6. Photopastegrams of several starches of Job's tears.

A, 76505; a, 76501; b, 76502; c, 76503; d, 77509-2; e, 79513. Concentrations of the starch sus

pension were 0.1%.

10 J. Jpn. Soc. Starch Sc., Vol. 30, No. 1 (1983)

tore of gelatinization for juzudama starches were somewhat higher than those of hatomugi.

DSC thermograms

Thermograms of several starches are shown in Fig. 7. Onset temperature (To), peak temperature

(Tp) and recovery temperature (Tr) were obtained by extrapolation as shown in thermogram (Fig. 7e), and heat of gelatinization were calculated by measuring the areas surrounded by thermogram curves and base lines. These values were summarised in Table 4 for all samples.

Waxy-type starches of maize have a wider range of gelatinization temperature than those of non-waxy-type.24) Similar phenomena were observed in the waxy-type hatomugi starches (Fig. 7). Namely, their To values were lower than those of

juzudama and heat of gelatinization was higher than those of juzudama (Table 4).

Starch-granule susceptibility to amylases Figure 8 shows starch-granule susceptibility to

hog pancreas a-amylase and Fig . 9 shows those to a crude preparation of Rhizopus amagasakiense

glucoamylase. These figures are represented by the ratio of percent degradation of starch-granule to percent degradation of nonwaxy maize starch which is equal to 100. Starch-granules of the waxy-type hatomugi were degraded 2-3 times faster than those of nonwaxy maize for both amylases . :Degradation patterns of #79517 and (79519 (data were not shown here) were similar to those of

Fig. 7. DSC thermograms of starches of Job's tears.

A, 76505; D, Okayarna; E, Nakazato (waxy); F, Nakazato (nonwaxy); b, 76502; d, 77509-2; e, 79513.

waxy-type hatomugi. The phenomena were simi

lar in the other cereals.12,13>

Starch-granule susceptibility of juzudama showed a wide variation, that was, #76502 showed similar susceptibility to the nonwaxy maize, while

#76503 degraded same as the waxy-type hatomugi (Figs. 8 and 9). In #77509-2, #79513 (Figs. 8 and

Table 4. DSC characteristics of starches of Job's tears.

Properties of Job's Tears Starch 11

Fig. 8. Relative susceptibility values of starch

granules to pancreatin.

Fig. 9. Relative susceptibility values of starch

granules to glucoamylase.

9) and #79514 (data were not shown here), degradation patterns were intermediate between those of #76502 and #76503.

Although, starch-granules of nonwaxy-type have less susceptibility than those of waxy-type, in

general, different cases are reported in maize. Little difference are observed between waxy and nonwaxy-type starches,25) and susceptibility differ according to their genetic background in spite of similarity of starch eomponents,21) and it also differ for their kinds or lines but the starch-granules have the same genetic background.26,27) Therefore, it is confirmed that a wide variation for starch-

granule susceptibility to amylases of juzudama means genetic diversity of wild plant.

From the results, we confirmed that juzudama

had nonwaxy-type starches and hatomugi was waxy-type ones except Nakazato (nonwaxy). Starches of Nakazato (nonwaxy) gave similar properties to those of juzudama. However, it is not clear whether the result means existence of non-waxy-type of hatomugi nor xenia between hatomugi and juzudama because they easily cross each other.l) Few percents of nonglutinous (nonwaxy) rice grain mix among the glutinous (waxy) rice in open polination because of xenia. Such 2-3 % of contamination as shown in Okayama is presumed xenia from the case of rice. But it is difficult to

explain as the result of rarely occurred natural crossing that such large quantity of nonwaxytype

grains exist in Nakazato. Anyway the further study is in progress on the point.

There was insignificant difference between prop

erties of starches of Job's tears cultivated in Japan

and Korea. Differences for properties of starch

were not observed according to their cultivated orr

collected places.

Finally, there is a great resemblance in prop

erties of endosperm starches between Job's tears

and maize.

The authors thank to Dr. Mikio Kimata, Department

of Agricultural Botany, Tokyo Gakugei University, Tokyo, for supplying seeds of three strains of hatomugi and six strains of juzudama, and Nosangyo SinkO Syorei Kai, Mr. Hiroshi Takuma, Agriculture Research Center, Oita, and Mr. Makoto Yamamuro, Agricultural Extension Office, Fukuoka, for their help as getting seeds of hatomugi, and also to Professor Kazuyoshi Takiyama and Dr. Yoshimi Sugimoto, Department of Home Science, Mukogawa Women's University, for measurement of X-ray diffractograms and photo

pastegrams.

REFERENCES

1) S. SATO: Nortre Dame Seishin University Kiyo, 2,51 (1978).

2) S. NAKAO: Saibaishokubutsu to Noko no Kigen, Iwanami Syoten, Tokyo, pp. 56-57 (1966).

3) K. SASAKI: Inasaku Izen, Nippon Hoso Syuppan Kyokai, Tokyo, pp. 147-148 (1971).

4) T. KAKIYONE : Wakan Syoyaku, Hirokawa Syoten, Tokyo, pp. 280-281 (1971).

5) K. KOBAYASHI and T. MIZUSHIMA : Nogyogizyutsu, 33, 193 (1978).

6) T. MIZUSHIMA and K. K0BAYASHI: Okayama

12 J. Jpn. Soc. Starch Sci., Vol. 30, No. 1(1983)

Noshi Kenpo, 2, 51(1977). 7) S. HARAYAMA: Syokuhin Kogyo, 21(9), 39 (1978). 8) H. KoIsHI, Y. KATAYAMA (SUGAWA) and M.

TSUJINo: Osaka Shiritsu Daigaku Seikatsukagaku-Bu Kiyo, 28, 37 (1980).

9) T. OHARA: Zakkoku, Jusonbo, Tokyo, pp. 399-400 (1981).

10) S. SAKAMOTO: J. Jpn. Soc. Starch Sci., 29, 41

(1982). 11) J.H. KEMPTON: J. Hered.,12, 396 (1921). 12) S. SATO and Y. MIYATA : Nortre Dame Seishin

University Jiho, 21, 51(1976). 13) Y. TOMITA, Y. SUGIM0T0, S. SAKAMOTO and H.

FUWA: J. Nutr. Sci. Vitaminol., 27, 471 (1981). 14) Y. SUGIMOTO, K. YAMADA, S. SAKAMOTO and H.

FUWA: Starke, 33, 112 (1981).15) S.A. WATSON: Methods in Carbohydrate Chemis

try, Vol. 4, R.L. WHISTLER ed., Academic Press, Inc., New York, p.3 (1964).

16) M. SoEJIMA and K. SUGAWARA : Tanpakushitsu no Teiryoho, Tokyo Daigaku Shuppan Kai, Tokyo,

p. 89 (1971). 17) Y. IKAWA and H. FUWA: Starke, 32, 145 (1980). 118) M. DUSOIS, K.A. GILLES, J.K. HAMILTON, P.A.

PEERS and F. SMITH : Anal. Chem., 28, 350 (1956). 19) S. HIzuKURI and Y. TAKEDA : Abstracts, Work

shop on Biochemical, Nutritional and Industrial

Aspects of Starch and Other Cereal Carbohydrates,

p.3 (1980). 20) H. FUWA, M. NAKAJIMA, A. HAMADA and D.V.

GLOVER: Cereal Chem., 54, 230 (1977). 21) Y. IKAWA, D.V. GLOVER, Y. SUGIMOTO and H.

FUWA : Starke, 33, 9 (1981). 22) JR. KATZ and Th.B. VANITALLINE: Z. Phys.

Chem., A150, 90 (1980). 23) K. KAINUMA : Denpunkagaku Handbook, M.

NAKAMURA and S. SUZVKI eds., Asakura Shoten, Tokyo, pp. 287-288 (1977).

24) D.J. STEVENS and G.A.H. ELTON: Starke, 23, 8

(1971).25) H. FUWA, D.V. GLOVER, Y. SUGIMOTO, R. NISHI

MURA and M. TANAKA: Starke, 30, 367 (1978). 26) H. FUWA, D.V. GLOVER, Y. SUGIMOTO and M. TA

NAKA: J. Nutr. Sci. Vitaminol., 24, 437 (1978). 27) H. FUWA, T. TAKAYA and Y. SUGIM0TO: Mecha

nisms of Saccharide Polymerization and Depolym- erization, J.J. MARSHALL ed., Academic Press,

Inc., New York, p.73 (1980).

ハ トム ギ お よ び ジ ュズ ダマ 澱 粉 の

性 質 に つ い て

井 川 佳 子*・ 姜 　 美 伶**・ 朝 岡 正 子**

　 坂 本 寧 男***・ 不 破 英 次**

*福 岡教 育大学 家政科

(811-41宗 像市大 字赤間729)

**大 阪 市立大学 生活科学 部

(558大 阪 市住吉 区杉本3-3-138)

***京 都大学 農学部 植物生殖 質研究施 設

　　 (617向 日市物 集女町 中条1)

　ハ トム ギ(Coix lacrymajobi L. ma-yuen(Roman.)

Stapf.)お よ び ジ ュ ズ ダ マ(Coix lacryma-jobi L,.)の 胚 乳

澱 粉 を 用 い,ヨ ー ド呈 色,イ ソア ミラー ゼ で 枝 切 りした

澱 粉 の ゲル ろ過 に よ る成 分 分 別,フ ォ トペ ー ス トグ ラ フ

ィー とDSCに よ る熱 糊 化 特 性,ア ミ ラ ー ゼ に よ る澱 粉

粒 の 分 解 性 を 検 討 した.材 料 は ハ トム ギ5種(日 本 産3

種,韓 国 産2種),ジ ュ ズ ダ マ6種(日 本 産5種,韓 国 産

1種)で あ る.日 本 産 ハ トム ギ のOkayamaとNakazato

に は,ヨ ー ド染 色 に よ っ て 濃 青 色 に 染 ま る種 子 が 穀 粒 重

量 に し て そ れ ぞ れ2.4%と40.5%存 在 して い た.そ

こでOkayamaに つ い て は 褐 色 に染 ま る もち 性 穀 粒 の み,

Nakazatoに つ い て は も ち 性 の穀 粒 と濃 青 色 に染 ま る も

ち で な い もの と を選 別 し,そ れ ぞ れ をOkayama,　 Naka-

zato(waxy), Nakazato(nonwaxy)と し て,他 の穀 粒 と

同 様 に 澱 粉 調 製 の材 料 と した.

　検討 の結果,以 下 の知見 を得た.

　 1)基 本 的 にハ トムギは もち性,ジ ュズ ダマは うるち

性 であ った.

　2)成 分 組成,フ ォ トペー ス トグラムに よる糊化 特性

な どは,ト ウモ ロコシ澱粉 の もち と うるちにそれ ぞれ よ

く似て いた.

　 3)X線 回折 図形 はす べてA型 を示 した.

　4)ジ ュズ ダマ澱 粉 は酵素 分解性 に関 して比較的 幅広

い様子 を示 し,野 性種澱粉 の持 つ多様性 を うかが わせた.

　5)全 体 として,Coix属 の胚 乳澱粉 は分類学上 近縁

とされ る トウモ ロコシのそれ に近 似 であ った.