The Time of Occurrence and Physical Characteristics of Pistachio Early Splitting as Sources of Contamination with Aflatoxin in Three Commercial Cultivars of Pistachio in Kerman

Pistachio early splitting is the main source of aflatoxin contamination in the orchards. The time of pistachio early splitting occurrence in the orchards is very important and also physical and shell characteristics in identifying and omitting of them are critical factors in the processing plants. In the present study, the time of early splitting occurrence in three Iranian commercial cultivars of pistachio including Ohadi”, “Kalehghoochi” and “Ahmadaghaei” in two different regions (Koshkoyeh and Nogh) of Rafsanjan during 2012-2013 were evaluated. Their physical characteristics such as fresh and dry weight of fruit with and without hull, the moisture content of fruit, length, width and diameter of early split fruits were measured. Results showed that early splitting occurrence in Kalehghoochi occurred earlier than other cultivars. The highest percentage of early splitting occurred 15 days before harvest time. Percentage of fruit moisture without and with hull in early split pistachios with soft and smooth hull were 27 and 65%, in semi-dry hull 22 and 50% and in dry early split fruits 14 and 31%, respectively. Weight, length, width and diameter of dry nuts in early split fruits with soft and smooth hull were higher than early split fruits with a semi-dry and dry hull. The amount of total aflatoxin in different pistachio parts showed that the highest amount was belonged to kernel compared with hull and shell. No aflatoxin was detected in the hull of pistachio. Overall, the aflatoxin content of kernels in Ohadi, Kalehghoochi and Ahmadaghaei were 12, 25 and 21 times higher than the shell, respectively.