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Meq O2/kg (meq + kg)
Selected AbstractsEFFECT OF DIFFERENT STORAGE CONDITIONS ON THE LIPID FRACTION OF A VEGETABLE CREAMJOURNAL OF FOOD QUALITY, Issue 4 2008FEDERICO FERIOLI ABSTRACT Fatty acids (free and esterified), diglycerides, peroxides and total sterols were determined in a vegetable cream. Cream samples were analyzed when fresh and after storage for 3 and 6 months at 4, 15, 30C and room temperature (10,25C). The product showed a higher amount of unsaturated fatty acids (,50% of total fatty acids) with respect to milk fat and a low level of cholesterol (<0.01%). The phytosterol content (,14 mg/100 g of cream) was not high enough to contribute to a decrease in cholesterolemia. Lipid oxidation remained low during storage (peroxides: 2.0,3.0 meq O2/kg of fat), but a small increase was observed at room temperature after 6 months (about 6.0 meq O2/kg of fat). Free fatty acids never exceeded 0.3% of fat. Storage at 4C and 15C delayed lipolysis in comparison to storage at 30C and room temperature. PRACTICAL APPLICATIONS The analysis of a vegetable cream demonstrated that it was a shelf-stable product, showing a high stability toward lipid oxidation and lipolysis. Such a product might be employed as vehicle for healthy fat compounds like long-chain polyunsaturated fatty acids, phytosterols and fat-soluble vitamins. [source] PRELIMINARY EVALUATION OF THE APPLICATION OF THE FTIR SPECTROSCOPY TO CONTROL THE GEOGRAPHIC ORIGIN AND QUALITY OF VIRGIN OLIVE OILSJOURNAL OF FOOD QUALITY, Issue 4 2007ALESSANDRA BENDINI ABSTRACT A rapid Fourier transform infrared (FTIR) attenuated total reflectance spectroscopic method was applied to determine qualitative parameters such as free fatty acid (FFA) content and the peroxide value (POV) in virgin olive oils. Calibration models were constructed using partial least squares regression on a large number of virgin olive oil samples. The best results (R2 = 0.955, root mean square error in cross validation [RMSECV] = 0.15) to evaluate FFA content expressed in oleic acid % (w/w) were obtained considering a calibration range from 0.2 to 9.2% of FFA relative to 190 samples. For POV determination, the result obtained, built on 80 olive oil samples with a calibration range from 11.1 to 49.7 meq O2/kg of oil, was not satisfactory (R2 = 0.855, RMSECV = 3.96). We also investigated the capability of FTIR spectroscopy, in combination with multivariate analysis, to distinguish virgin olive oils based on geographic origin. The spectra of 84 monovarietal virgin olive oil samples from eight Italian regions were collected and elaborated by principal component analysis (PCA), considering the fingerprint region. The results were satisfactory and could successfully discriminate the majority of samples coming from the Emilia Romagna, Sardinian and Sicilian regions. Moreover, the explained variance from this PCA was higher than 96%. PRACTICAL APPLICATIONS The verification of the declared origin or the determination of the origin of an unidentified virgin olive oil is a challenging problem. In this work, we have studied the applicability of Fourier transform infrared coupled with multivariate statistical analysis to discriminate the geographic origin of virgin olive oil samples from different Italian regions. [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] COMPARISON 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] Effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii ENGLINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2007César Kapseu Summary The effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii (ENGL) was investigated. Air drying studies carried out on B. coriacea and B. parkii, tropical food sources subject to high post-harvest losses, have resulted in the establishment of a significant difference between oil yields extracted from samples of various particle size pretreatments (paste, 4 mm, 8 mm and whole kernels) dried at 45 and 60 °C with the highest oil yield given by the 4 mm thick slices dried at 45 °C. The influence of temperature and particle thickness on the drying rate has been evaluated. The drying constants were found to depend on both temperature and particle thickness. Analysis of the oil extracted from the 4 mm thick slices dried at 45 °C showed that apart from the acid value (52.4%), the saponification (181.2 mg g,1 KOH), peroxide (8.6 meq kg,1) and the unsaponifiable (7.43%) matter values of the extracted shea butter remain within the limits cited in the literature while a close analysis of the cake suggests that it could be a good mineral source. [source] Characterisation of avocado (Persea americana Mill) honeys by their physicochemical characteristicsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2004Anass Terrab Abstract The quality of 12 avocado (Persea americana Mill) honeys from Spain was evaluated. Eight common physicochemical parameters were analysed, namely water content, pH, acidity (free, lactonic and total), sugar content, ash content and electrical conductivity. In addition, the honey samples were analysed using inductively coupled plasma optical emission spectrometry (ICP-OES), and six minerals were quantified for each honey, namely potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), phosphorus (P) and sulphur (S). Most samples showed proper maturity considering the medium water content (mean 17.7%). The total acidity (below 50 meq kg,1 except for one sample) indicated absence of undesirable fermentation; also, the mean pH of around 4.77 is usual in this kind of honey. The values for ash content and electrical conductivity were high (0.77% and 798 µS cm,1 respectively) and typical of dark honeys. K was the predominant mineral (accounting for 73% of the total minerals quantified), followed by Na (10%). Copyright © 2004 Society of Chemical Industry [source] Stability of Crude Herring Oil Produced from Fresh Byproducts: Influence of Temperature during StorageJOURNAL OF FOOD SCIENCE, Issue 9 2002I. Aidos ABSTRACT: Crude herring oil, extracted from fresh byproducts, was stored at 0, 20, and 50°C in order to study the effect of temperature on lipid oxidation. The oil had an initial peroxide value (PV), anisidine value (AV), and free fatty acids of 0.7 meq peroxides/kg of lipid, 0.4, and 0.6%, respectively. During storage, the oil reached the secondary oxidation stage for all 3 temperatures. The formation of fluorescent compounds was inhibited at 0°C. Significant decrease of the ,-tocopherol content was found after storage at 0 and 20°C, but no consumption occurred at 50°C. The development of oxidation products over time exhibited a temperature-dependency with a very good correlation. [source] | ||||||||||