Institute of Standards and Industrial Research of Iran (ISIRI) defines standards for the following Iranian pistachio products:
- In-Shell Pistachio Nuts: ISIRI 15 4th revision
- Mechanically Opened Pistachio Nuts: ISIRI 4919 1st revision
- Closed Shell Pistachio Nuts: ISIRI 4921 1st revision
- Pistachio Kernels: ISIRI 218 4th revision
- Split Pistachio Kernels: ISIRI 3639 1st revision
- Green Peeled Pistachio Kernels: ISIRI 4631 1st revision
- Pistachio Oil: ISIRI 6655 no revision
- Pistachio Paste: ISIRI 5691 no revision
- Pistachio Powder: ISIRI 9636 no revision
The following table contains an abridged version of specifications for the five pistachio grades set out by ISIRI Standard 15 (4th Revision January 2009) for in-shell pistachio nuts (including raw dried and roasted pistachios):
| Superior Grade |
Excellent Grade |
Grade 1 |
Grade 2 |
Grade 3 |
|
| Shell Defects (%) (allowable tolerances by weight) |
|||||
| Closed shell and blanks |
1 |
2 |
3 |
4 |
5 |
| Blanks |
0.5 |
0.75 |
0.75 |
1 |
1 |
| Adhering hull |
0.5 |
0.75 |
1 |
1.25 |
1.5 |
| Stained shell |
1 |
1.5 |
4 |
5 |
6 |
| Deformity (incl. opened from bottom) |
1 |
2 |
3 |
5 |
6 |
| Slightly open in-shell |
5 |
10 |
18 |
25 |
N/A |
| Total shell defects |
7 |
13 |
22 |
28 |
N/A |
| Kernel Defects (%) (allowable tolerances by weight) |
|||||
| Loose kernels |
1 |
2 |
2.5 |
3 |
3.5 |
| Pest damage |
3 |
4 |
5 |
5 |
6 |
| Obvious pest damage |
1 |
2 |
3 |
3 |
3 |
| Total kernel defects |
3 |
4 |
5 |
6 |
7 |
| Other Defects (%) (allowable tolerances by weight) |
|||||
| Foreign material |
0.25 |
0.3 |
0.4 |
0.6 |
0.8 |
| Foreign material excluding shells |
0.2 |
0.2 |
0.25 |
0.25 |
0.3 |
| Non-uniformity of variety |
1 |
2 |
3 |
4 |
5 |
| Non-uniformity of size |
1.5 |
1.6 |
1.8 |
2 |
2.4 |
Maximum Allowable Moisture Content: For raw dried pistachios: maximum 5% free water content, and for roasted pistachios: maximum 3% free water content.
Some Definitions:
Foreign material: Glass, metal and live insects are considered completely prohibited foreign materials. Acceptable foreign materials are pistachio related debris such as hull, stems, shells and sand.
Variety: Iranian pistachios are categorized into two categories according to their shape: long pistachios, where the ratio of the length to the largest diameter is more than 1.52; and round pistachios, where the ratio of the length to the largest diameter is less than 1.52.
Non-uniformity of variety: The percentage of round pistachios in a sample of long pistachios or vice versa.
Non-uniformity of Size: Ratio of the total weight of the 10 largest nuts in a sample of 100 nuts to the weight of the smallest 10.
