Physico-chemical characteristics of olives and olive oil from two mono-cultivars during various ripening phases.
The aim of this study was to find a correlation between the chemical and physical parameters in the pulp of the olive, in order to identify the optimum period during the 1998 harvesting period. For this reason various parameters have been monitored: the amount of oil in the pulp during the ripening phase obtained by solvent extraction with n-hexane, the acidity, the peroxide value, the composition of fatty acids and the saturated/unsaturated fatty acid ratio, the composition of the unsaponifiable fraction, the antioxidant capacity, the percentage of oil and the puncture test in two local Croatian olive cultivars. The chemical parameters change during the ripening, in order to control the oxidative changes of the cellular homeostasis of the whole lipophilic fraction that needs a stronger safeguard of the double bonds against the oxidative stress. The modification of the physical characteristics, observed with the puncture test, is related to the chemical changes which occur in the olive during the ripening period and the monitoring of these physical and chemical parameters can help to increase nutritional quality (as antioxidant capacity) and allow for an acceptable amount of oil.
Finotti
E
E
National Institute for Food and Nutrition Research, Via Ardeatina 546, I-00178 Rome, Italy. e.finotti@agora.it
Beye
C
C
Nardo
N
N
Quaglia
G B
GB
Milin
C
C
Giacometti
J
J
D000975:Antioxidants / Q000032:analysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005227:Fatty Acids / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D009753:Nutritive Value; D000069463:Olive Oil; D010938:Plant Oils / Q000737:chemistry*; D013997:Time Factors
D000975:Antioxidants; D005227:Fatty Acids; D000069463:Olive Oil; D010938:Plant Oils