Standards

Iranian Pistachio standards

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.