Summary of interesting research results (Part 8)admin | December 11, 2010
Oil yields, polyphenols and colour depth were higher, and oils were clearer when made using Pectinex Ultra SP-L and Pectinase 1.6021 enzymes compared with untreated controls. Pectinex treatment was more effective than Pectinase in increased polyphenols in Koroneiki oils.
Najafian et al. (2009) Aqueous extraction of virgin olive oil using industrial enzymes. Food Research International 42, 171-175.
Potted mature Koroneiki and Mastoidis trees subjected to increasingly salty irrigation produced fruit with higher moisture and lower oil content. Increasing salinity produced oils with higher phenolics and lower oleic acid levels.
Stefanoudaki et al. (2009) Olive oil qualitative parameters after orchard irrigation with saline water. Journal of Agricultural and Food Chemistry 57, 1421-1425.
The phenolic oleocanthal induced pungency that was mostly perceived at the back of the throat and was most intense at 15 seconds after eating. Significant variation between individuals was observed.
Cicerale et al. (2009) Sensory characterization of the irritant properties of Oleocanthal, a natural anti-inflammatory agent in extra virgin olive oils. Chemical Senses 34, 333-339.
A 10 yr study of 4856 adults found an association between oleic acid intake and reduced risk of depression in women. No association between intake and incidence of depression was observed in men.
Wolf et al. (2009) Dietary linoleic and oleic acids in relation to severe depressed mood: 10 years follow-up of a national cohort. Progress in Neuro-psychopharmacology and Biological Psychiatry, 33, 972-977.
Irrigating at 25% of that required to meet evapotranspiration throughout the entire growing season and only during midsummer both reduced per hectare oil yield by around 15%. Irrigating up to evapotranspiration cost 1 megalitre of water for each extra 10kg of oil produced.
Iniesta et al. (2009) The effects of regulated and continuous deficit irrigation on the water use, growth and yield of olive trees. European Journal of Agronomy 30, 258-265.
Comment: In Australia water is currently being traded on the open market at around $40 per megalitre – so irrigating to this extent would increase the cost of production by a massive $4 (EUR 3) per kg – aka more than EVOO is currently worth.
Destoning olives prior to crushing produced oils with higher polyphenols and tocopherol than those made with whole olives. The addition of cytolase enzyme further increased these components while talc addition during malaxation had little effect.
Ranalli et al. (2009) Evaluation of functional phytchemicals in destoned virgin olive oil. Food Bioprocess and Technology 2, 322-327.
The blue tasting glasses used in EVOO assessment do not effectively mask the colour of olive oils. Between glass variation was significant and higher than the variation in colour of the different oils in the same glass.
Melgosa et al. (2009) Color measurements in blue-tinted cups for virgin-olive-oil tasting. J. Americal Oil Chemists Society, 86, 627-636. Comment: I’ve never been convinced of the need to cover the colour up anyway. Recite after me “green oils aren’t always herbaceous and yellow oils aren’t always ripe” Got it? Pretty straightforward after all.