THE MACADAMIA NUT IN HAWAII 
11 
The rough-shell kernel conforms fairly well to the same division 
into grades. However, the differences in texture, color, and flavor 
between the rough and smooth types persist throughout all specific- 
gravity grades. 
QUALITY- RATIO ME1 HOD Of SCORING M ACAD AMI A NUTS 
General standards have been set up for the grading of the more 
common commercial nuts. These have to do with the size and appear- 
ance of the unshelled nut, the relative wholeness of the kernels upon 
extraction from the shell, the color, size, and plumpness of the kernel, 
and its condition with respect to insect infestation {3, 8). These 
standards have been set up largely from the standpoint of market- 
ing the nut in the unshelled form. 
The macadamia crop in Hawaii, coming as it does from seedlings, 
different types, numerous localities, and with great differences in 
cultural care, is subject to great fluctuation in nut characteristics. 
There is need for some method of evaluation of these qualities from 
i lie standpoint of both commercial value and selection. 
The method of evaluating macadamias as finally developed is 
designed to determine the pounds of unshelled nuts required to 
produce 1 pound of grade 1 roasted kernel. This is designated "qual- 
ity ratio." The following factors enter into this ratio: 
SIZING OF UNSHELLED NUTS 
Three screens with round holes 2.75, 2.45, and 2.10 cm in diameter, 
respectively, are used to divide the unshelled nuts. The four sizes 
of nuts are thus >2.75 cm, 2.75 to 2.45 cm, 2.45 to 2.10 cm, and 
<2.10 cm in diameter. All nuts of a diameter >2.1() cm are given 
full value and are termed sizable while those <2.10 cm are termed 
culls with no value. This division between sizable nuts and culls is 
based on commercial practice. Nuts of the cull size are irregular in 
size, shape, and quality. Discarding of cull nuts likewise serves to 
eliminate objectionably small sizes of kernels. No further account 
i< taken of size of nut or of kernel in calculation of quality ratio. 
PROPORTION OF KERNEL 
The sizable nuts are cracked and the percent of kernels calculated. 
GRADING OF KERNELS 
The kernels of the sizable nuts are graded as in the regular specific- 
gravity method and the percent of kernels which are grade 1 deter- 
mined. Grades 2 and 3 are given no value. 
QUALITY RATIO 
Calculation of the quality ratio is as follows: 
Quality ratio = 
100 
Percent sizable nuts X percent kernel X percent grade 1 kernels 
An attempt was made to incorporate a color grading into the 
piality ratio. The normal macadamia kernel has a cream-colored 
