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Free Acidity (free + acidity)
Selected AbstractsCOMPARISON OF THE VIRGIN OLIVE OILS PRODUCED IN DIFFERENT REGIONS OF TURKEYJOURNAL OF SENSORY STUDIES, Issue 3 2009MUSTAFA Ö ABSTRACT Virgin olive oils from different regions of Turkey were collected and analyzed. The total phenolics and antioxidant capacity of the samples ranged from 30.26 to 208.61 mg gallic acid/kg and 0.60 to 5.61 Trolox equivalents/kg, respectively. Free acidity (0.44,7.31% oleic acid), peroxide value (6.83,39.60 meq O2/kg), total volatiles (0.11,0.37%), viscosity (65.50,85.40 cP), K232 value (1.30,2.54), K270 value (0.08,0.30), refractive index (1.470) and descriptive sensory properties of the samples were also measured. The multidimensional scaling (MDS) analysis indicated that positive and negative attributes classification of the olive oil sensory defining terms were mostly the case, and total phenolics content by itself may be a useful classification index. Also, MDS maps showed that the samples from Southeastern and Aegean regions are closer, while others are separate from each other. PRACTICAL APPLICATIONS Data for the physicochemical and sensory descriptive properties of virgin olive oils from Turkey are provided for the scientific community, olive oil consumers and traders. Also, utilization of sensory data by multidimensional scaling technique for geographical origin groupings provides a unique insight for researchers for similar objectives. In addition, some findings (i.e., the eligibility of phenolics content by itself for olive oil classification) of this article produce new results for fast and practical application purposes yet confirmed by other researchers. [source] Shelf life of vegetable oils bottled in different scavenging polyethyleneterephthalate (PET) containersPACKAGING TECHNOLOGY AND SCIENCE, Issue 5 2008R. Sacchi Abstract The shelf life of extra virgin olive oil (EVOO) and sunflower oil (SO) bottled in containers with different levels of oxygen scavenger (OS) and stored at room temperature under diffuse lighting conditions for 6 months has been evaluated. Four packaging materials were tested: glass, polyethyleneterephthalate (PET), PET including 1% of OS (PET 1%) and PET including 5% of OS (PET 5%). Free acidity, peroxide value (PV), spectrophotometric indices (K232, K270, ,K), antioxidant (biophenols and tocopherols) content, pigment (chlorophylls and carotenoids) change and the amount of oxygen dissolved in the oil were monitored during storage. A significant influence of the packaging material on the quality decay was not found. The differences in the shelf life observed between oils bottled in PET and oils bottled in glass are attributable to a difference in the initial content of dissolved oxygen in the oils. The study showed the usefulness of monitoring changes in dissolved oxygen level, antioxidant (phenols and tocopherols) and pigment (chlorophyll and carotenoids) profiles during oil storage. The change of these compounds could in fact supply important information on the oxidation processes that occur in bottled oils and on the effectiveness of the material employed in oil packaging. Copyright © 2007 John Wiley & Sons, Ltd. [source] Palynological, physico-chemical and colour characterization of Moroccan honeys.INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2003Summary The palynological, physico-chemical and chromatic properties of twelve samples of Moroccan orange honeys were measured. A minimum of 10% of Citrus sp. pollen is considered enough to consider a honey as unifloral. These honeys are poor in pollen grains (PG) , eleven of the twelve samples show less than 20 000 PG per 10 g of honey. The presence of Eucalyptus, Plantago, Anthemis arvensis, Sinapis arvensis, Olea europaea, Acacia and Quercus pollen allows the differentiation of these honeys from those with a different geographical origin. From the physico-chemical point of view, the honeys present a low level of sucrose, ash and minerals content, and medium,high values for the water content, electrical conductivity, free acidity and maltose. Melezitose is not present in any samples. As for the chromatic parameters, the luminance (Y), along with the lightness (L*) and chroma showed very low values. [source] EFFECT OF STORAGE PERIOD AND EXPOSURE CONDITIONS ON THE QUALITY OF BOSANA EXTRA-VIRGIN OLIVE OILJOURNAL OF FOOD QUALITY, Issue 2 2006VINCENZO VACCA ABSTRACT Changes in quality parameters, antioxidant compounds, oxidative stability and antioxidant activity during 18 months of storage of a monovarietal extra-virgin olive oil from Bosana cultivar, and exposed to light and dark, were studied. Analysis of data showed that all the parameters underwent significant changes during storage: free acidity, peroxide and ultraviolet (UV) spectrophotometric indexes remained below the limits reported in the EEC Regulations 2568/91 and 1989/03, and these are: ,0.8% for acidity, ,20 meq O2/kg for peroxide and ,2.50 and ,0.22 for K232 and K270, respectively. Phenol and, -tocopherol content decreased during storage (42.0 and 29.6%, respectively) while chlorophylls and carotenoids underwent a decrease until 8 months of storage (49% and 30%, respectively); after that, the values remained constant. Oxidative stability and antioxidant activity had not changed dramatically during 18 months. Phenols were significantly correlated to the antioxidant activity of the oil, while oxidative stability measured by Rancimat did not show any correlation with carotenoids, chlorophylls, phenols and, -tocopherol. Regarding exposure conditions, storage in the dark was better in retaining the quality of the oil, as expected. [source] | ||||||||||