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):
|
Specifications
|
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.