Lucky dip of interesting research results (Part 6)
admin | November 28, 2010The authors’ summaries of these papers can be found on-line. Just cut and paste the title of the paper into your search engine.
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Fertilising with olive mill waste water (OMW) increased the ratio of soil fungi to bacteria but decreased root growth. The polyphenol content of the oil increased with OMW irrigation. Fatty acid profiles were unaltered.
Mechri et al. (2010) Olive orchard amended with olive mill wastewater: Effects on olive fruit and olive oil quality. Journal of Hazardous Materials 172 (2009) 1544–1550.
Comment: The increase in oil polyphenols with increased irrigation was surprising.
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A Mediterranean diet including olive and sunflower oil was associated with reduced breast cancer risk in postmenopausal women provided their energy intake was low. Conversely, a western type diet was associated with increased risk particularly in women with a high body mass index.
Cottet et al. (2009) Postmenopausal breast cancer risk and dietary patterns in the E3N-EPIC prospective cohort study. American Journal of Epidemiology, 170, 1257-1267.
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The free fatty acidity of a virgin olive oil stored for three years in polyethylene was higher, and colour density lower than when stored in stainless steel or glass. The contaminant styrene was detected in oil stored in polyethylene.
Aly and Ravid (2009) Effect of storage conditions on virgin olive oil quality. Israel Journal of Plant Sciences, 56, 273-278.
Comment: Like most studies of this type, the plastic used was clear, but the glass/other containers were dark or did not transmit light. Therefore it is impossible to separate the effect of container material from container transparency. The appropriate control for this experiment was a clear glass bottle. In addition, the type of stopper almost certainly differed. Significant oxygen transmission can (and does) occur through the stopper. This important factor was not addressed.
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The attributes which affected the perceived quality of EVOO differed between French and Tunisian consumers. Price was the most important attribute for both groups. French consumers valued region and the use of traditional pressing, while Tunisians valued varietal oils and modern extraction methods.
Dekhili and d’Hauteville (2009) Effect of the region of origin on the perceived quality of olive oil: An experimental approach using a control group. Food Quality and Preference, 20, 525-532.
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Irrigating 50yr old Koroneiki trees produced oils with lower levels of the bitter phenolic oleoropin and the peppery phenolic oleocanthal, but irrigation resulted in a higher (more desirable) ratio of monounsaturated to polyunsaturated fats compared with a rain fed control.
Stefanoudaki et al. (2009) Effect of irrigation on quality attributes of olive oil. J. Agric. Food Chem. 2009, 57, 7048–7055.
Comment: It is uncommon for agronomic factors to affect fatty acid profiles.
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When harvested with a trunk shaker, greater than 80% of Picual olives broke free at the pedicel (point closest to the fruit) regardless of ripeness. Around a half of Hojiblanca olives broke free at the peduncle and rachis (closer to the shoot) when in a “straw-green” ripeness stage, but greater than 80% broke free at the pedicel when harvested later.
Castillo-Llanque and Rapoport (2009) Identifying the location of olive fruit abscission. Scientia Horticulturae 120, 292-295.
Comment: I’m sure someone, somewhere will be interested in this 🙂
No authoritative or regulatory body anywhere in the world classifies styrene to be a known cause of human cancer. Moreover, a study conducted by a \blue ribbon\ panel of epidemiologists and published in the peer-reviewed Journal of Occupational and Environmental Medicine (November 2009) reports: \The evidence of human carcinogenicity of styrene is inconsistent and weak. On the basis of the available evidence, one cannot conclude that there is a causal relationship between styrene and any type of human cancer.\
Priscilla Briones for the Styrene Information and Research Center (SIRC), Arlington, Virginia. SIRC (www.styrene.org) is a trade association representing interests of the North American styrene industry with its mission being the collection, development, analysis and communication of pertinent information on styrene.
While the review Ms. Briones cites (which SIRC commissioned, and then paid the authors to give testimony to the National Toxicology Program) did find what she says, the more authoritative and independent WHO body, the International Agency for Research on Cancer (IARC) has classified styrene as a Group 2B carcinogen (“possibly carcinogenic to humans”) since 1987, and IARC reaffirmed that styrene is a Group 2B carcinogen in 2002.
Without making a clear judgement and carcinogenicity, California EPA’s Office of Environmental Health Hazard Assessment finds that “The most relevant chronic noncancer effect due to styrene exposure is neurotoxicity,” citing multiple human studies documenting clear dose-dependent neurological deficits in workers with occupational exposure to styrene, which is hardly reassuring, whatever its effects on cancer.