Japanese Rice Producers' Shift from High Yield to High Palatability and Quality -Characteristics of Highly Palatable Rice-

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Josephine Turner
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1 Jurnal f Develpments in Sustainable Agriculture 5: 96-1 (21) Japanese Rice Prducers' Shift frm High Yield t High Palatability and Quality -Characteristics f Highly Palatable Rice- Yuji Nitta* Cllege f Agriculture, Ibaraki University, Ami, Ibaraki, Japan In 1962, Japanese peple cnsumed kg year-i persn-i f rice. Hwever, after decreasing cntinuusly fr fur decades, cnsumptin was nly 61.9 kg year-i persn -I in 23. Since the 198s, Japanese peple have preferred highly palatable, high-quality rice prducts instead f quantity. We investigated sme palatability prperties and characteristics f rice prducts in different regins arund Japan. Thicker brwn rice and heavier brwn rice were thught t have high palatability and quality, traits that have been assciated with lw percentages f prtein andlr amylse. Hwever, ur results shwed that these tw characteristics were nt related t palatability in the case f thicker brwn rice. The surface and the interir ultrastructure f cked rice als affect palatability. In highly palatable cked rice, thin fibrus and mesh-like surface structures are well develped; mesh-like and spngy structures are als detectable inside. In cntrast, the surface f cked rice f lw-palatability is cvered with gel-like structures and has less-develped fibrus and mesh-like structures; fewer mesh-like structures are detectable inside. Different cultivars and envirnmental cnditins als affect palatability and quality. The majr cnditins are the effects f high r lw temperature, water status, and strng rain r wind during the ripening perid. Currently we are analyzing the ripening prcess and hw envirnmental cnditins during ripening affect rice palatability and quality. Key wrds: Envirnment, Paddy, Prductin Intrductin Rice is an imprtant cereal crp fr the entire wrld in terms f its prductin and the nutritin it supplies. Wrld prductin f rugh rice was nly 225 millin tns when the first mdern rice varieties were develped in the early 196s (Fig. la) (Lampe, 1994). During the next 4 years, wrld rice prductin increased by abut 35 millin tns. Rice cultivatin ccupies abut 153 millin ha fr 2, with an average yield (prductivity per unit grwing area) f 3.9 tn ha- 1 (Fig. 2) (IRRI 25). Causal factrs f the remarkable increase f rugh rice prductin are (a) develpment f highyielding varieties, (b) develpment f varieties with high resistance against pests and disease, (c) increase in irrigated area, (d) increased chemical fertilizer applicatin, and (e) develpment f widely adaptable varieties. Mre than 9 % f the ttal area f rice prductin is in Asia (Fig. la). Nrth and Central America, Suth America, Africa and Eurpe have each prduced less than ten thusand tns/year f rugh rice (Lampe, 1994). Amng Asian cuntries, rice prductin is greatest in China, fllwed by India and Indnesia, with smaller amunts in ther cuntries (Fig. IB) (Lampe, 1994). Since the 196s, large increases in yield have been seen in Japan, Krea, China and Turkey (Fig. 2). Hwever, nly slight increases are apparent in Indnesia, Bangladesh and sme ther cuntries. These limited increases are attributable t the fllwing: (a) because f limited irrigatin, the water supply fr mst paddy fields is dependent n rain- Received: Octber 28, 29, Accepted: December 21, 29 * Crrespnding authr: Cllege f Agriculture, Ibaraki University, Ami, Ibaraki 3-393, Japan. nittay@mx.ibaraki.ac.jp

2 Nitta: Japanese Rice Prducers' Shift frm High yield t High palatability and Quality c 6.9 E 5 '--" c 4.. " (j) c --*-Africa..c 1 -e-eurpe bl) Wrld -7E-Nrth & Central America Bangladesh C Japan Myanmar -t-philippines s '--" -Thailand C 15 -Vietnam China '.p " Indnesia c 5...c bl) Fig. 1. Rugh rice prductin in the wrld (A) and Asian cuntries (B). fall, (b) intensive labr was nt applied, and (c) the supply f chemical fertilizers was insufficient in thse cuntries. Therefre, even within Asia, differences in farming practices result in very different agricultural utput. Cnsumptin Trends f Japanese Peple Accrding t the Ministry f Agriculture, Frestry and Fisheries (29), Japanese peple cnsumed 118.3kg year- 1 persn- 1 in which has decreased cntinuusly fr fur decades (Fig. 3). In 23, nly 61.9 kg year- 1 persn- 1 was cnsumed. There are many reasns fr the decrease in rice cnsumptin. One reasn is thught t be related t fd supply and Japanese peple's preferences. ( a) Since the 196s, Japan has undergne cultural. changes s that western fds, such as bread, eggs, meat, milk, cffee, and dairy prducts are widely cnsumed. (b) Japanese children prefer western fd: hamburgers, curry with rice, and spaghetti Fig S,-.. C\i c: C\i 8.S. 6 S C 4 ti.l 2 U Fig. 3. Rugh rice yield in Asian cuntries Milled rice cnsumptin in Japan. have becme ppular with Japanese families. (c) Frzen, prcessed, and precked fds are mre readily available in supermarkets. (d) There are much greater pprtunities t eat meals utside the hme. The ther reasn fr the decrease in rice cnsumptin is thught t be scial changes. (a) In the past, wrkers wuld cnsume a hmemade lunch. Hwever, mre recently, lunch is eaten in restaurants r cnvenience stres. (b) Schl lunch prgrams in elementary and junir high schls have been widely develped. (c) Meals have becme mre diverse: Japanese, Chinese, and western dishes are cnsumed at hme and at restaurants. On the ther hand, Japanese peple prefer t eat rice prducts f high palatability and quality. This trend has been evident since the 198s. In general, sft and sticky cked rice is preferred by Japanese peple. This preference has affected which varieties f rice are cultivated in Japan (Fig. 4). Befre the 198s, many varieties were grwn. Hwever, in the

3 98 J. Dev. Sus. Agr. 5 (1) 5, --; 4, 5 Fig. 4. Rice cultivatin areas by varieties in Japan. 198s, Japanese peple began t prefer highly palatable rice. Cnsequently, Kshihikari, which is mst famus fr its high palatability, has becme the mst ppular cultivar and is currentiy grwn n 55, ha, which amunts t abut ne-third f all paddy fields in Japan (1.69 millin ha)(22). As a result, cultivars f high-yielding rice r rice with high-resistance against insects r diseases, including Kinmaze, Fujiminri, Akihikari, have vanished. Characteristics f Palatability and Quality in Rice Prducts We investigated sme characteristics assciated with palatability and quality f rice prducts derived frm different regins arund Japan. Brwn rice thickness and 1-grain brwn rice weight are imprtant markers fr palatability and quality (Matsue et al., 1994). Thicker brwn rice and heavier brwn rice are thught t have high palatability and t be f high quality. The physicchemical prperties thught t be assciated with palatability are the percentages f prtein and/r amylse. As previusly reprted, brwn rice f lw prtein and/r amylse cntent has high palatability (Matsue et al., 21). Hwever, ur results shwed that in the case f thicker brwn rice, these tw prperties were nt related t palatability (Fig. 5). Ultra Fine Structures f High-palatability Cked Rice Rice quality is evaluated nt nly by external prperties such as grain size, r weight but als by the palatability f the cked rice. A cmmn methd f evaluating this characteristic is t b a r=-.39 NS b 8 r=-.232 NS 9 85 c 8 88) r=.226 NS WOO-grain weight f brwn rice (g) Fig. 5. Relatins between 1-grain weight r thickness f brwn rice and prtein r amylase cntent and palatability index f milled rice. NS: nt significant. (Nitta et at., 25)

Nitta: Japanese Rice Prducers' Shift frm High yield t High palatability and Quality 99 Fig. 6. Scanning electrn micrgraphs f high palatability cked rice (cv. Kshihikari).

4 Nitta: Japanese Rice Prducers' Shift frm High yield t High palatability and Quality 99 Fig. 6. Scanning electrn micrgraphs f high palatability cked rice (cv. Kshihikari). a: surface structure, b: inner structure. Fig. 7. Scanning electrn micrgraphs f lw palatability cked rice (cv. Akihikari). a: surface structure, b: inner structure. serve ultra fine structures by using a scanning electrn micrscpe (Matsuda et a!., 1993). Figure 6a shws the surface view f highly palatable cked rice (cv. Kshihikari). Develped fibrus and meshlike structures are bserved. Internally, there are well defined mesh-like structures and spngy tissues (Fig. 6b). These prperties are thught t be related t weak hardness and strng stickiness when cnsumed. In Japan, peple generally prefer sftness and stickiness. In cntrast, the lw palatability cked rice cv. Akihikari is cvered with gel-like membranes and has a less develped fibrus r mesh-like surface structure (Fig. 7a); inside this cked rice, less defined mesh-like structures are bserved, similar t thse f the surface (Fig. 7b). Cultural and envirnmental cnditins affect palatability. In additin, structural changes in amylpectin is als imprtant fr determining palatability. The relatinship between the fine structure f cked rice and mlecular structures such as side chain length f amylpectin will be investigated fr further research. Cnclusin The amunt f rice prduced is different amng cuntries. The prblem is that the yield is different amng cuntries due t cultural situatins. Lw yielding cuntries need t pay mre effrts t increase rice yield in this century during which the ppulatin is expected t increase mre and mre. Hwever, the standpint fr rice prductin is als different amng cuntries. The mst typical feature can be seen in Japan. Namely, rice cnsumptin has decreased in Japan, while rice palatability and quality has becme imprtant since the 198's. Rice palatability and quality are influenced by different cultivars as well as envirnmental cnditins. Effects f temperature extremes, water status, and strng rain r wind during the ripening perid are majr factrs. We evaluated rice palatability and quality by electrn micrscpic bservatins. Highly palatable cked rice is characterized by fibrus

5 1 J. Dev. Sus. Agr. 5 (1) and mesh-like structures n the surface as well as by well defined mesh-like structures and spngy tissues inside. We are als analyzed the ripening prcess as affected by envirnmental factrs. References IRRI 25. Atlas f Rice & Wrld Rice Statistics. Lampe, K., Frewrd. In Breaking the Yield Barrier (ed. Cassman, K.). Internatinal Rice Research Institute, Ls Bans, Philippines, 5. Matsuda, T., H. Hara and N. Chnan, Fine structure and palatability f cked rice. XII Characteristics f high palatability cked rice. Jpn. J. Crp Sci. 62 (extra 2): (in Japanese) Matsue, Y., K. Odahara and M. Hiramatsu, Differences in prtein cntent, amylase cntent and palatability in relatin t lcatin f grains within rice panicle. Jpn. J. Crp Sci. 63: Matsue, Y., H. Sat and Y. Uchimura, 21. The palatability and physicchemical prperties f milled rice fr each grain-thickness grup. Plant Prd. Sci. 4: Ministry f Agriculture, Frestry and Fisheries, 29. Change f rice cnsumptin. Nitta, Y., Y. In, T. Matsuda, Y.!ida and S. Tsukamt, 28. Crrelatin f palatability prperties with grainweight and thickness f rice grain -Case f cv. Kshihikari cultivated in Ibaraki prefecture in 25-. Jpn. J. Crp Sci. 77: (in Japanese with English abstract)

UNIT 2: mapping bananas

Oxfam Educatin www.xfam.rg.uk/educatin UNIT 2: mapping bananas Age range: 7-11 years Outline Learners will investigate sme f the cuntries where the bananas we eat in the UK are grwn. They will first lcate