Opposite oleic acid responses to temperature in oils from the seed and mesocarp of the olive fruit
Olive oil is mostly extracted from the mesocarp [95 per cent] of the fruit with the seed [endosperm and embryo, 5 per cent] containing little oil. There are correlative and manipulative evidence that temperature modulates fruit oil content and fatty acid composition of the oil from the whole fruit [i.e., with no distinction beingmade between oils derived from each oil-bearing structure] of olive. Notably, oleic acid concentration ofolive oil decreases as fruit mean growth temperature increases. This response in the olive fruit is oppositeto that documented in annual oil-seed crops such as sunflower and soybean. The objectives of the presentstudy were: i] to compare temperature effects on fatty acid composition of oil derived from seed and frommesocarp; ii] to compare temperature effects on seed and mesocarp dry weights and oil concentrations. Todo this, fruiting branches were enclosed in transparent plastic chambers with individualized temperaturecontrol. Temperature was manipulated during the seed growth [Period A] and during the second halfof mesocarp growth [Period B] subphases. In both periods, the oleic acid proportion in mesocarp oildecreased as temperature increased, and was accompanied by increases of palmitic acid, linoleic andlinolenic acids Mesocarp dry weight did not respond significantly to temperature, but mesocarp oilconcentration fell significantly as temperature increased. Seed dry weight, oil concentration and fatty acidcomposition exhibited responses to temperature during Period A only, with seed dry weight increasingbetween 20 and 25.C with a sharp decrease at higher temperature, and oil concentration linearly falling 1.2 per cent per.C. In contrast, seed oil oleic acid percentage increased between 20 and 28.C, and fell slightlywith higher temperature. Palmitic and stearic acids in seed oil increased sigmoidally with temperature, while linoleic acid decreased sigmoidally. Oleic acid percentage showed opposite responses in oil fromthe seed and the mesocarp. The response of the seed to temperature was similar to those observed inoil from embryos of annual oil-seed crops, although the abrupt fall in palmitic and stearic acid with temperature mayor to 25.C seems to be distinctive for olive seed oil.
| Main Authors: | , , , |
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| Format: | Texto biblioteca |
| Language: | eng |
| Subjects: | OLIVE OIL, OLEIC ACID, LINOLEIC ACID, STEARIC ACID, INCREASING TEMPERATURE, |
| Online Access: | http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber=47356 http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber= http://ceiba.agro.uba.ar/cgi-bin/koha/opac-detail.pl?biblionumber= |
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