TY - JOUR
T1 - Optimizing olive harvest time under hot climatic conditions of Jordan Valley, Israel
AU - Dag, Arnon
AU - Harlev, Guy
AU - Lavee, Shimon
AU - Zipori, Isaac
AU - Kerem, Zohar
PY - 2014/2
Y1 - 2014/2
N2 - Global climate change leads to the exposure of olive orchards to higher temperatures than in the past. We followed yield and quality parameters of olive oils from Barnea, Coratina, and Picual, under hot climatic conditions through different levels of ripeness. Oil yield per tree increased throughout the monitoring period due to continuous oil accumulation. Toward the last harvest date, significant fruit drop occurred, which resulted in substantial loss in oil yield. Maximal oil yield was obtained in Barnea at a maturity index of 2.1-2.5, in Coratina at 2.3 and in Picual at 3.2. A reduction in quality parameters was found with delay of harvest date: free fatty acid content increased and the ratio of monounsaturated to polyunsaturated fatty acid declined, but only in one season. Nevertheless, all parameters remained within the trade standard for extra virgin olive oil (EVOO). In contrast to most previous studies, no consistent reduction was observed in total polar phenol content in the oils. Hence, maximizing oil yield should be the main criterion for the determination of harvest date under these conditions. It is therefore suggested that olives exposed to hot climate be harvested earlier than those in typical Mediterranean climate areas. Practical applications: Harvest timing has a strong effect on both oil yield and quality. However, in most of the studies published on the topic until now only a sample of fruit was taken to determine oil accumulation and quality, but little or no information is available on oil yield at tree level, which is an important parameter from the grower's perspective. Moreover, this study describes changes in oil yield and quality along the ripening period, under hot climatic conditions prevailing in Jordan Valley. The Mediterranean basin region, where more than 90% of the world's olive oil is produced is expected to be exposed to higher temperatures in the future due to global climate changes. The current work provides information on the effect of those unfavorable growing conditions on oil production and quality. One of the major findings is the necessity to harvest early (in a relatively low ripening index) under those conditions.
AB - Global climate change leads to the exposure of olive orchards to higher temperatures than in the past. We followed yield and quality parameters of olive oils from Barnea, Coratina, and Picual, under hot climatic conditions through different levels of ripeness. Oil yield per tree increased throughout the monitoring period due to continuous oil accumulation. Toward the last harvest date, significant fruit drop occurred, which resulted in substantial loss in oil yield. Maximal oil yield was obtained in Barnea at a maturity index of 2.1-2.5, in Coratina at 2.3 and in Picual at 3.2. A reduction in quality parameters was found with delay of harvest date: free fatty acid content increased and the ratio of monounsaturated to polyunsaturated fatty acid declined, but only in one season. Nevertheless, all parameters remained within the trade standard for extra virgin olive oil (EVOO). In contrast to most previous studies, no consistent reduction was observed in total polar phenol content in the oils. Hence, maximizing oil yield should be the main criterion for the determination of harvest date under these conditions. It is therefore suggested that olives exposed to hot climate be harvested earlier than those in typical Mediterranean climate areas. Practical applications: Harvest timing has a strong effect on both oil yield and quality. However, in most of the studies published on the topic until now only a sample of fruit was taken to determine oil accumulation and quality, but little or no information is available on oil yield at tree level, which is an important parameter from the grower's perspective. Moreover, this study describes changes in oil yield and quality along the ripening period, under hot climatic conditions prevailing in Jordan Valley. The Mediterranean basin region, where more than 90% of the world's olive oil is produced is expected to be exposed to higher temperatures in the future due to global climate changes. The current work provides information on the effect of those unfavorable growing conditions on oil production and quality. One of the major findings is the necessity to harvest early (in a relatively low ripening index) under those conditions.
KW - Fatty acids profile
KW - Global climate change
KW - Maturity index
KW - Oil quality
KW - Yield
UR - http://www.scopus.com/inward/record.url?scp=84893474895&partnerID=8YFLogxK
U2 - 10.1002/ejlt.201300211
DO - 10.1002/ejlt.201300211
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:84893474895
SN - 1438-7697
VL - 116
SP - 169
EP - 176
JO - European Journal of Lipid Science and Technology
JF - European Journal of Lipid Science and Technology
IS - 2
ER -