Document Type : Original Article

Authors

1 Agricultural Engineering Research Department, Kerman Agricultural and Resource Research and Education Center, AREEO, Kerman, Iran

2 assistant prof of Agricultural Engineering Research institute. Agricultural research, education and organization. Karaj .Iran

3 Assistant Prof. of Agricultural Engineering Research Department, fares Agricultural and Resource Research and Education Center, AREEO, Fares, Iran.

4 Forests and rangeland research department kerman agricultural resource research and education center. AREEO.K erman iran.

Abstract

 In this study, two methods of opening the pistachio shell (ice and mechanical methods) and natural opening at two storage temperatures (10°C and 25°C) and six months storage for Ouhadi pistachio cultivar, were compared in terms of peroxide index, acid number and sensory proprties. The results showed that the rate of changes in peroxide index during six months of storage varied from 2 to 3 mEq / kg, the changes in acid rate ranged from 0.51 to 0.85 mg / g and the moisture content of the samples varied from 4.36 % to 6.23 %. The highest amount of acidity (0.85 mg / g) and peroxide index (3.1 mEq /kg) in open shell samples was observed in the ice openenig method and storage tempreture of 25° C. The lowest acidity (0.51 mg / g) and peroxide index (2 mEq / kg) was observed in mechanical method opening and storage tempreture of 10 ° C. However, with the increasing of the storage time, peroxide index and acidity were incresed but the peroxide index at the end of storage in all treatments was found lower than the recommended safe limit (5 mEq /kg). The highest percentage (92%) and rate of shell opening (6.4 mm) were obtained by mechanical method. The percentage of pistachios that were crushed by the mechanical method was 2% and 3% higher than that in other two methods, respectively. According to the panel judges, the mechanical method was more desirable than the other two treatments with 86.5% of total acceptability. According to the significant effect of the appearance and chemical properties on the acceptability of the pistachio, it was concluded that the mechanical shell opening method was more acceptable method for artificially shell opening than the other methods.

Keywords

 Abdullahi Ezzatabadi, M. (2011). Economic study of the relationship between price and quality in the domestic market of Iranian pistachios: A case study of Kerman province. Agricultural Economics Research, 3(3), 172-157. DOR:  20.1001.1.20086407.1390.3.11.9.8. (in Persian)
 
Anon. (2007). Pistachio kernel characteristics and test methods. No. 218. Fourth Reprint. Iranian Institute of Standards and Industrial Research of Iran, National Standard of Iran. (in Persian)
 
Anon. (2016). Faostat. Food and Agriculture Organization of the United Nations, 2010.
 
Crane, J. C., & Iwakiri, B. T. (1982). Shell dehiscence in pistachio. HortScience, 17(5), 797-98.
 
Daneshmandi., M. Sh., Azizi, M., & Farhosh, R. (2013). Investigation of physical, chemical and biochemical properties of pistachio (Pistachio vera L. cv. Danesshmandi) in comparison with some commercial cultivars in Khorasan province. Journal of Horticultural Sciences (Agricultural Sciences and Industries), 28(1), 10-17. DOI: 10.22067/JHORTS4.V0I0.34996. (in Persian)
 
Esmaeilpour, A., & Shakerardekani, A. (2018). Effects of early harvest times on nut quality and physiological characteristics of pistachio (Pistacia vera) trees. Fruits, 73(2), 110-117.
 
Ferguson, L., Polito, V., & Kallsen C. (2005a). The  pistachio  tree; botany  and physiology  and  factors  that  affect yield.  Pistachio Production  Manual.  4th  Ed  Davis,  CA,  USA,  University  of California Fruit & Nut Research Information Center.
 
Ferguson L, Kader A., & Thompson T. (2005b). Harvesting, transporting, processing and grading. The Manual. UCCE Pistachio Production Short Course.
 
Gazor, H., & Minaei, S. (2005). Influence of temperature and air velocity on drying time and quality parameters of Pistachio (Pistacia vera L.). Drying Technology, 23(12), 2463-2475. DOI: 10.1080/07373930500341708.
 
Gazor, H., Minaei, S., & Rostami, M, A. (2003). Investigating the effects of temperature and product thickness on pistachio drying process in box dryers. Agricultural Sciences and Natural Resources, 11(4), 81- 94. (in Persian)
 
Maghsoudi, H., Khoshtaghaza, M. H., & Minaei, S. (2010). Selected geometric characteristics, density, and mechanical properties of unsplit pistachio nut. International Journal of Food Properties, 13, 394-403. DOI: 10.1080/10942910802571745.
 
Maghsoudi, H., Khoshtaghaza, H., Minaei, S., & Zaki Dizaji. H. (2012). Fracture resistance of Unsplit Pistachio (Pistacia vera L.) nuts against splitting force, under compressive loading. Journal of Agricultural Science and Technology (JAST), 14, 299-310. DOR: 20.1001.1.16807073.2012.14.2.1.3.
 
Mohsenin N. N. 1986. Physical properties of plant and animal materials. New York: Gordon & Breach Science Publishers.
 
Piggot, J. R. (1996). Statisical procedures in food research. Elsevier Applied Science, New York.
 
Raei, M., & Jafari, S. M. (2013). Influence of modified atmospheric conditions and different packaging materials on pistachio (Pistacia vera L.) oil quality. Latin American Applied Research, 43(1), 43-46.
 
Sedaghat, N. (2010). Application of arrhenius kinetics to evaluate stability of pistachio nuts at various conditions. Middle East Journal of Scientific Research, 6(3):224-229.
 
Sedaghat, N., Mortazavi, A., Nasiri Mahallati, M., & Davari Nejad, Gh. (2005). Estimation of shelf life of pistachios in different storage conditions. Journal of Agricultural Sciences and Natural Resources, 12(2), 127-134. (in Persian)
 
Shaker Ardakani, A. (2007). Harvesting, processing, storage and packaging of pistachios. National Pistachio Research Institute. First Ed. (in Persian)
 
Shayanfar, S., & Kashaninejad, M. (2012). The effect of different non-mechanical treatments on splitting pistachio nuts. Journal of Nuts, 3(3), 1-4.
 
Sherafati, A. M., Hokmabadi, H., & Sabeti, A. (2008). The most important varieties of pistachios in Khorasan and their role in production and export. Proceedings of the First National Conference on Pistachio Processing and Packaging, Dec. 4-5, Ferdowsi University of Mashhad, Mashhad, Iran. (in Persian)
 
Tavakolipour, H. (2000). Optimization and design of drying processes and pistachio storage conditions (Ph. D. Thesis), Food Science and Technology Engineering, Islamic Azad University-Science and Research Branch, Faculty of Engineering. Tehran, Iran. (in Persian)
 
Tavakolipour, H., Basiri, A., & A. Kalbasi Ashtari, A. (2008). Effects of temperature and relative humidity of storage environment on pistachio quality indices during storage period. Quarterly Journal of Food Science and Technology, 5(4), 57-66. (in Persian)
 
Zare Nazari, A. (2013). Investigation of pistachio dryers and energy consumption in them. Iran Pistachio Association Website. (in Persian)