Lucky dip of research results (Part 5)
admin | November 20, 2010Microwaving extra virgin olive oil retained tocopherols better than when heated conventionally. Heating reduced total phenols by 29% regardless of heating method.
Bendini et al. (2009) Study on the effects of heating of virgin olive oil blended with mildly deodorized olive oil: Focus on the hydrolytic and oxidative state. Journal of Agricultural and Food Chemistry, 57,10055-10062.
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Losses of chlorophyll and carotenoids began after microwaving samples of extra virgin olive oil for 3 minutes at 1000W. Tocopherol began to decline at around one minute, had declined by a third after 5 minutes and was completely absent after 10 minutes of microwaving.
Malheiro et al. (2009) Effect of microwave heating with different exposure times on physical and chemical parameters of olive oil. Food and Chemical Toxicology, 47, 92-97.
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In home use consumer tests, consumers of olive oil from Southern Italy were given a branded oil and the same oil but this time with a guaranteed origin statement on the label. Despite it having the same sensory profile, the guaranteed origin oil had a higher acceptability amongst the consumers. Consumers also tended to like an oil more if it met with their expectations.
Caporale and Monteleone (2001) Sciences des Ailients, 21: 243-245.
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Adding pulverised Calcium carbonate (common chalk) powder to the paste during (laboratory scale) malaxation improved oil extraction by between 1.0 and 3.7kg oil/100kg fruit depending on variety. The increase was similar to that obtained using the more expensive (by 3-4x) microcrystalline talc.
Espinola et al. (2009) Improved extraction of virgin olive oil using calcium carbonate as coadjuvant extractant. Journal of Food Engineering, 92, 112-118.
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Field grown Chemlali trees irrigated with saline water (ECe=7.5 dSm-1) produced oil with slightly higher phenolics and oleic acid levels. Yield (kg/tree) was reduced by 43% under saline irrigation partly due to smaller fruit size. Oil yield was also reduced by 2%.
Ahmed et al. (2009) Saline water irrigation effects on fruit development, quality, and phenolic composition of virgin olive oils, Cv. Chemlali. Journal of Agricultural and Food Chemistry 57, 2803-2811.
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Enzymes in olives flesh that break down fats causing higher acidity and lower oil quality most active at normal processing pH (4.8), 35C and in the presence of calcium.
Panzararo et al. (2010) Biochemical characterization of a lipase from olive fruit (Olea europaea L.) Plant Physiology and Biochemistry. 48, 741-745.
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A 10 year cohort study of 41,078 Spaniards showed that consumption of vegetables, olive oil and fruit reduced the risk of coronary heart disease (in order of importance). Consumption of dairy products, meat and cereals increased risk (in order of importance). The risk of CHD was not associated with legume consumption.
Buckland et al. (2009) Adherence to the Mediterranean Diet and Risk of Coronary Heart Disease in the Spanish EPIC Cohort Study. American Journal of Epidemiology, 170, 1518-1529.
