Bulk modulus of five major varieties of Iranian pistachios

Abstract

The bulk modulus coefficients of five major varieties of Iranian pistachios (Ahmad_aghayee, Akbari, Badami, Fandoghi and Kaleh_ghoochi) were interpreted. Bulk pistachios with 5%-7% (d.b.) moisture content and the equivalent spherical radii (3.51-3.90 mm) in one, two and three layers were stressed with a universal 10,000 kg testing machine.  The slopes of the linear models of the pressure vs. strain curves were estimated as the bulk modulus of the relevant pistachios layers, which were 0.94, 1.104 and 1.15 N/mm² for one, two and three layers of pistachios, respectively.  The analysis of the data showed no statistically significant difference among the five varieties at the 95.0% confidence level.

Keywords: bulk modulus, shelling, pistachios