Chapter 1. Rice

The best qualities of rice come from Mino, Higo, Ise, Owari, Totomi, and Hizen. The next best are from Boshiu, Tamba, Tajima, and the third quality from Kadzusa, Shimosa, Musashi, and Kaga.

The following analyses of the two kinds of rice were made in the University -laboratory.

Table 1. Analyses of Hulled Rice of Various Years

	Common Rice							Glutinous Rice
	Ise 1877	Mino 1877	Banshiu 1877	Ise 1879	Mino 1879	Sendai 1879	1880	Koshi-gaya 1877	Kazai 1877	1879
Water	11.96	18.02	12.86	11.79	11.54	12.63	11.96	12.41	12.60	10.56
Sugar and Dextrin	3.22	3.52	6.45	1.49	2.60	3.94	1.99	4.78	4.40	4.06
Ash	.72	.87	1.12	1.17	1.22	.88	.58	1.45	1.05	1.12
Albumenoids	4.79	5.07	5.13	1.04	.98	5.69	1.76	4.30	4.30	.74
Albumenoids				5.74	4.99		5.42			5.62
Starch	74.69	72.52	69.23	73.31	73.73	72.54	73.31	72.80	72.81	70.15
Cellulose	2.98	3.13	3.27	2.56	2.54	2.35	3.68	2.79	2.67	3.63
Fat	.90	1.21	1.85	1.27	1.57	.94	1.07	1.30	1.18	2.48
Ash	.74	.66	.09	.14	.10	.54	.22	.16	.99	.38
	100.00	100.00	100.00	98.51	99.27	99.51	99.99	100.00	100.00	98.74

No essential difference in chemical composition between the two kinds of rice is disclosed by the foregoing analyses, but the two grains can be distinguished at the first glance after removing the husk, the common rice being translucent, whilst the glutinous rice is white and opaque. The name "glutinous rice" is given to the latter, doubtless, from the peculiarity it possesses of forming, when steamed and beaten, pasty lumps of great tenacity, a property which is not shared by the common rice. It is a similar property to that possessed by wheaten flour, and in that grain is due to the presence of a peculiar nitrogenous body galled "gliadin" which is not present to any marked extent in other grains. This substance is soluble in hot alcohol and if it were present in glutinous rice might be expected to be found in the alcoholic solution, but experiments made for that purpose have not shown any great difference between the two kinds of rice in the proportion of albumenoids dissolved by alcohol. Nor is there any difference in the amounts soluble in cold water; the only essential difference I have been able to detect is in the action of iodine solution upon the flour, that of common rice being colored deep blue, like starch, and that of the glutinous variety red, like dextrin. The cause of this difference more probably lies in the nature of the albumenoids than in the proportion of dextrin.

The weight of a given bulk of rice varies considerably according to the way in which it is packed, and in calculating the weights of rice used in sake-brewing from the volume, I have taken what may be considered a fair average, vis. 40 kuwamme per koku. This is founded upon the following direct weighings. One sho of the specified kinds of rice was loosely placed in the measure, and without shaking, carefully levelled; each number is the mean of seven weighings.

		Weight of one sho (grams)	Weight of one koku (kuwamme)
Common Rice	Kazai	1391	37.03
	Sendai	1346	35.83
	Mino	1379	36.72
	Ise	1401	37.30
Glutinous rice	Kazai	1394	37.12
		Mean	36.80

When the rice was tightly packed, that is, after being well shaken down, the average weight of one koku was 42 kuwamme, and as a rough average between the weights when loosely and when tightly packed, 40 kuwamme per koku will not be far from the truth.

The rice grain is a complex structure formed of a great many distinct parts, som e of which can be readily parted by ordinary mechanical appliances, while others can only be separated by special means. Of the former is the hard outer coat, i tself composed of several different parts, which is generally removed by the far mer as chaff before the rice is sent into the market. The hulled grain, in the form in which it is bought for food consists of three easily discernible parts, a thin, yellowish skin on the outside (the testa), within this the white starchy matter which constitutes the nutritious part of the grain (the endosperm), and at the lower end a portion of a different appearance, usually horny and shrivelled looking (the embryo). Immediately below the testa the cells of the endosperm do not differ in general appearance from those in the interior, but the greater part of the albumenoid matter of the endosperm is accumulated in these cells. An excellent test for the presence of albumenoids is mercuric nitrate; if a section of a grain of rice be steeped in such a solution those portions which contain albumenoid matter become colored rice, whilst the rest of the grain remains uncolored. When a thin slice of the unwhitened grain is thus treated the cells forming the testa have a somewhat greenish color and can be sharply distinguished from the layer immediately within, which is deeply colored red. This coloration extends inwards for a distance a little greater than the thickness of the test, but the form of the cells thus colored does not appear to be different from the remainder of those forming the endosperm, and which assume no coloration. In a similar section of whitened rice the outer layer of greenish, square cells is not seen, and the edges present a jagged appearance, but the outer cells are as strongly colored red as before, showing that only a small portion, if any, of the cells containing nitrogenous matter has been removed. In fact, the thickness of the layer colored red cannot be said to have perceptibly diminished. The red coloration is not uniform but is distributed over numerous points, being stronger near the testa and becoming fainter away from it; under a high power distinct points of red matter can be distinguished; these are the aleurone grains.

When the rice grain is whitened the testa is removed by beating, and analyses show that the bran so obtained contains much more nitrogen than the average of the entire hulled grain. The two following analyses are taken from a paper on "The Agricultural Chemistry of Japan" by Prof. Kinch.²

	A	B
Water	10.96	11.05
Ash	9.11	9.22
Oil	13.20	15.50
Fibre	7.66	8.60
Albumenoids	13.41	13.55
Soluble carbohydrates	45.66	42.08
	100.0	100.0

These analyses show that the ash, oil, fibre, and albumenoids are contained in large proportions in the bran. Together with the testa, which is mainly fibre, or cellulose, the embryo is removed, and it is from that source that most of the fat and nitrogenous matter is derived. Notwithstanding the large percentage of albumenoid matter contained in the bran, that in the whitened rice has not very greatly diminished: thus in one specimen which contained 7.4 percent before cleaning, afterwards 6.9 percent was found, the proportion of moisture being the same in each. As the bran contains so much nitrogenous matter it might have been expected that the grain after whitening would have shown a marked diminution; that it does not do so is owing to the fact that the whitened grains are selected, those which are unbroken being separated from those which have been much broken. Thus there result on the one hand grains broken into minute portions containing very little nitrogen, and sold to the same maker, on the other, the unbroken, whitened grains containing still almost all the protein matter of the endosperm, and deprived of testa and embryo which together form the bran (nuka), and contain the largest percentage of albumenoids.

The following analyses of the whitened rice grain are given because from them the samples of koji, the composition of which is given afterwards (see Table 8) were prepared. A is the rice used for making koji at the Yushima works; B is the rice used at the Tokyo brewery in the operations described in Part II.

Table 2: Composition of Whitened Rice Dried at 100° C.

	A	B
Starch	82.27 %	82.14 %
Cellulose	4.79	3.02
Fat	.49	1.12
Ash	.46	.16
Albumenoids	7.5 9.45 1.95	8.82
Albumenoids
Dextrose and Dextrine	1.91	3.97
Ash	.63	.77
	100.00	100.00
Water	12.70	12.19

² Trans. Asiat. Soc. Japan, VIII. 393.