The effect of irrigation level and harvest mechanization on virgin olive oil quality in a traditional rain-fed 'Souri' olive orchard converted to irrigation.

摘要

Effects of olive grove irrigation and harvesting regimes on quality of resulting virgin olive oils were studied. Souri olive trees were left non-irrigated (rain-fed control) or irrigated to 25-125% of reference evapotranspiration (ET0) and harvested over 2 consecutive seasons by either hand picking or mechanical harvesting. Oils obtained from the different treatments were analysed for free acidity, polyphenols and peroxide value. Increasing level of irrigation was associated with increases in oil free acidity and decreases in total phenols concn. Mechanical harvesting resulted in virgin olive oils with higher free acidity, lower polyphenol concn. and slightly higher peroxide value than oils obtained from hand-picked olives. Results suggest that irrigation can enhance sensitivity of olive fruits to mechanical wounding resulting in oils of increased free acidity, higher peroxide value and lower levels of total phenols.