Physicochemical Characterization of Jordanian Air Dried Olive Fruits

Abstract

The effect of indoor air drying on the mass of irrigated and rain - fed green and black olives has been investigated in the present study. Mass loss data were collected over a drying period of about four months. Several measurements were carried out on the p it and pulp fractions of the dried samples. These measurements included the determination of: Mass percentages of pits and pulp fractions, mineral and fat contents, percentages of carbon, hydrogen and nitrogen, gross and net calorific values. Results base d on using simultaneous thermogravimetry and differential thermal analysi s, derivative thermogravimetry and differential scanning calorimetry are reported for pits derived from rain - fed green and black olives. The maximum average % ma ss loss was found to b e 78.99 % for irrigated green olives while the minimum average % mass loss was found to be 34.48 % for rain - fed black olives. The percentages of pulp and pits for dry green olives fall in the range 57 .59 - 65.18% and 33.91 - 39.98 %, respectively. The corresp onding ranges for the dry black olives are 65.13 - 76.70 and 20.65 - 33.76 % for pulp and pits fractions. The gross calorific values are 21.609 and 21.745 kJ/g on dry basis for pits of rain - fed green and black olives. Soxhlet extraction with n - hexane of rai n - fed olives gave extractives percentages of 23.39 and 21.84 % for pits of green and b lack olives and 46.43 and 51.80 % for pulp fraction of green and black olives, respectively. The pyrolysis thermograms gave residual masses of 0.29 and 0.27 at 600 ° C for pi ts Original Research Article