Ioannis K. Karabagias

Shelf life extension of lamb meat using thyme or oregano essential oils and modified atmosphere packaging.

The effect of thyme (TEO) and oregano (OEO) essential oils as well as modified atmosphere packaging (MAP) in extending the shelf life of fresh lamb meat stored at 4 °C was investigated. In a preliminary experiment TEO and OEO were used at concentrations 0.1 and 0.3% v/w while MAP tested included MAP1 (60% CO(2)/40% N(2)) and MAP2 (80% CO(2)/20% N(2)). Microbiological, physicochemical and sensory properties of lamb meat were monitored over a 20 day period. Sensory analysis showed that at the higher concentration both essential oils gave a strong objectionable odour and taste and were not further used. Of the two essential oils TEO was more effective as was MAP2 over MAP1 for lamb meat preservation. In a second experiment the combined effect of TEO (0.1%) and MAP2 (80/20) on shelf life extension of lamb meat was evaluated over a 25 day storage period. Microbial populations were reduced up to 2.8 log cfu/g on day 9 of storage with the most pronounced effect being achieved by the combination MAP2 plus TEO (0.1%). TBA values varied for all treatments and remained lower than 4 mg MDA/kg throughout storage. pH values varied between 6.4 and 6.0 during storage. Color parameters (L and b) increased with storage time while parameter (a) remained unaffected. Based primarily on sensory analysis (odour) but also on microbiological data, shelf life of lamb meat was 7 days for air packaged samples, 9-10 days for samples containing 0.1% of TEO and 21-22 days for MAP packaged samples containing 0.1% TEO.

Characterisation and classification of Greek pine honeys according to their geographical origin based on volatiles, physicochemical parameters and chemometrics.

The aim of the present study was to characterise and classify Greek pine honeys according to geographical origin, based on the determination of volatile compounds and physicochemical parameters using MANOVA and Linear Discriminant Analysis. Thirty-nine pine honey samples were collected during the harvesting period 2011 from 4 different regions in Greece known to produce good quality pine honey. The analysis of volatile compounds was performed by Headspace Solid Phase Microextraction-Gas Chromatography/Mass Spectroscopy. Fifty-five volatile compounds were tentatively identified and semi quantified. Physicochemical parameter analysis included the determination of pH, free, lactonic and total acidity, electrical conductivity, moisture, ash, lactonic/free acidity ratio and colour parameters L(∗), a(∗), b(∗). Using 8 selected volatile compounds and 11 physicochemical parameters, the honey samples were satisfactorily classified according to geographical origin using volatile compounds (84.6% correct prediction), physicochemical parameters (79.5% correct prediction) and the combination of both (74.4% correct prediction).

Botanical discrimination of Greek unifloral honeys with physico-chemical and chemometric analyses

The aim of the present study was to investigate the possibility of characterisation and classification of Greek unifloral honeys (pine, thyme, fir and orange blossom) according to botanical origin using volatile compounds, conventional physico-chemical parameters and chemometric analyses (MANOVA and Linear Discriminant Analysis). For this purpose, 119 honey samples were collected during the harvesting period 2011 from 14 different regions in Greece known to produce unifloral honey of good quality. Physico-chemical analysis included the identification and semi quantification of fifty five volatile compounds performed by Headspace Solid Phase Microextraction coupled to gas chromatography/mass spectroscopy and the determination of conventional quality parameters such as pH, free, lactonic, total acidity, electrical conductivity, moisture, ash, lactonic/free acidity ratio and colour parameters L, a, b. Results showed that using 40 diverse variables (30 volatile compounds of different classes and 10 physico-chemical parameters) the honey samples were satisfactorily classified according to botanical origin using volatile compounds (84.0% correct prediction), physicochemical parameters (97.5% correct prediction), and the combination of both (95.8% correct prediction) indicating that multi element analysis comprises a powerful tool for honey discrimination purposes.

Characterization and classification of commercial thyme honeys produced in specific Mediterranean countries according to geographical origin, using physicochemical parameter values and mineral content in combination with chemometrics

The aim of the present study was to provide information on physicochemical (pH, free, lactonic, and total acidity, electrical conductivity, moisture, ash, lactonic/free acidity), colour parameters (L*, a*, b*), and mineral content (Ag, Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Sb, Se, Si, Ti, Tl, V, Zn) of 34 commercial thyme honeys produced in Egypt, Morocco, Greece, and Spain, in terms of characterization and geographical discrimination using MANOVA/LDA, chemometric analyses. Conventional physicochemical and colour parameters were determined using official methods of analysis. Minerals were quantified using inductively coupled plasma optical emission spectroscopy (ICP-OES). Results showed that all honey samples analysed met the standard quality criteria set by the EU. In order to classify honeys according to geographical origin, MANOVA and LDA were applied in sequence. Respective classification rates based on cross-validation method were: 91.2, 76.5, and 88.2%, using 10 physicochemical and colour parameters, 12 minerals, and their combination, respectively. Testing whether the determined physicochemical parameters of commercial Mediterranean thyme honeys could be applied to routine quality control serving as honey origin predictors showed positive results. Finally, such a combination of data enhances honey quality control and authentication efforts, at an international level.

Impact of physicochemical parameters, pollen grains, and phenolic compounds on the correct geographical differentiation of fir honeys produced in Greece as assessed by multivariate analyses

ABSTRACT In the present study, the effect of different parameters on the correct geographical differentiation of Greek fir honey was investigated. Forty-three honey samples were collected from four regions and subjected to physicochemical and melissopalynological analyses, using official and instrumental methods. Results showed that fir honeys met the European regulatory quality standards, whereas significant differences (p < 0.05) were recorded for all the determined parameters according to geographical origin. The highest differentiation rate (81.4%) was recorded using the combination of six physicochemical parameters and five phenolic compounds, as assessed by multivariate analyses.

Differentiation of Fresh Greek Orange Juice of the Merlin Cultivar According to Geographical Origin Based on the Combination of Organic Acid and Sugar Content as well as Physicochemical Parameters Using Chemometrics

The aim of the present study was to differentiate fresh Greek orange juice prepared from the Merlin cultivar according to geographical origin, based on organic acid/sugar content, and physicochemical parameter analysis, using chemometrics. For this purpose, oranges were collected during the harvesting period 2013–2014 from four different regions in Greece where Merlin oranges are produced. The analysis of organic acids and sugars was performed using a modified high pressure liquid chromatographic (HPLC–DAD/RI) method. Applying MANOVA and LDA analysis to the collected data, orange juices were successfully classified according to geographical origin (correct classification rate 83.3%). For validation purposes of the applied model, oranges from the harvesting period 2014–2015 were also collected and new instrumental and chemometric analysis carried out involving orange juice from both harvesting periods. Cumulative results showed that the classification rate remained practically constant, recording a correct classification rate of 80.4%, confirming the discriminatory power of the applied model. In order to further improve the overall classification rate, physicochemical parameter data were subjected to chemometric analysis along with organic acid and sugar content data. Results showed that the combination of organic acids, sugars, and physicochemical parameters somewhat increased the overall correct prediction rate to 82.0%. Present results enhance the potential of multi-parameter analysis for the correct geographical differentiation of Greek fresh orange juice, aiding to product quality and authenticity control.

Geographical discrimination of pine and fir honeys using multivariate analyses of major and minor honey components identified by 1 H NMR and HPLC along with physicochemical data

The objective of the present work was the geographical discrimination of the most common honeydew honeys produced in Greece, namely pine and fir, on the basis of sugar, free amino acid and organic acid content, determined by nuclear magnetic resonance spectroscopy (1H NMR) and high-performance liquid chromatography (HPLC), along with moisture content, sugar ratios, or sugars to moisture ratio, using chemometrics. For this purpose, 39 pine and 31 fir honey samples were collected from professional beekeepers from eight different regions in Greece. Data were subjected to multivariate analysis and modeled using supervised statistical methods. The combination of 1H NMR and HPLC based on metabolites along with the aforementioned physicochemical data resulted in the geographical discrimination of pine and fir honeys. Respective prediction rates were 76.9 and 80.6%, using a model validation technique: the cross-validation method. Present results support the combined use of instrumental and conventional methods for honey geographical origin differentiation.

Volatile fraction of commercial thyme honeys produced in Mediterranean regions and key volatile compounds for geographical discrimination: A chemometric approach

ABSTRACT The aim of the present study was to investigate the volatile fraction and discriminate 34 commercial thyme honeys from Morocco, Egypt, Spain, and Greece according to geographical origin, using key volatile compounds in combination with chemometrics. Sixty-two volatile compounds belonging to different classes were identified and semi-quantified using headspace solid phase micro-extraction coupled to gas chromatography/mass spectrometry (HS-SPME-GC/MS). Applying chemometric analyses to 17 volatiles (p < 0.05), honeys were successfully discriminated according to geographical origin. Correct classification rate was 88.2% using the cross-validation method. Volatile compounds proved to be a powerful tool for discriminating commercial thyme honeys from different countries.

Characterization and differentiation of sheep's milk from Greek breeds based on physicochemical parameters, fatty acid composition and volatile profile: Characterization and differentiation of sheep's milk from Greek breeds

BACKGROUND There are only limited studies in the literature attempting to differentiate sheeps milk originating from different sheep breeds. In the present study the physicochemical parameters (pH, percent fat, percent protein, percent lactose and percent total solids), fatty acid composition and volatile profile of raw milk from four autochthonous Greek breeds (Karagouniko, Mpoutsiko, Artas and Chios) were determined. The objective of the present study was to characterize and differentiate the sheep breeds based on the above analytical parameters in combination with chemometrics. RESULTS The overall correct classification rate was 79.7%%, 84.4% and 100% based on physicochemical parameters, fatty acid composition and volatile profile, respectively. Volatiles proved to be the most effective of parameters analyzed for the differentiation of sheep breed. Furthermore, the combination of physicochemical parameters and fatty acid composition gave a correct classification rate equal to 96.9%. CONCLUSION Either volatile profile or the combination of physicochemical parameters and fatty acid composition may be easily determined and used for the differentiation of sheeps milk from four different Greek breeds, this being the novelty of the present work. This may be very important in terms of PDO (Protected Designation of Origin) and PGI (Protected Geographical Indication) products related to specific geographical origin and sensory characteristics.

Characterization and Botanical Differentiation of Monofloral and Multifloral Honeys Produced in Cyprus, Greece, and Egypt Using Physicochemical Parameter Analysis and Mineral Content in Conjunction with Supervised Statistical Techniques

Thirty-four honey samples donated by beekeepers and purchased from supermarkets were collected during harvesting years 2010–2014 from Cyprus, Greece, and Egypt. The aims of this study were to characterize honey samples and, if possible, to differentiate honeys according to the honey type on the basis of physicochemical parameter values, mineral content, and their combination using supervised statistical techniques (linear discriminant analysis (LDA)). Physicochemical parameters (colour, pH, free acidity, total dissolved solids, salinity, electrical conductivity, and moisture content) were determined according to official methods, while minerals (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, P, Pb, Sb, Si, Ti, Tl, V, and Zn) using inductively coupled plasma optical emission spectrometry. The majority of honey samples analyzed met the quality criteria set by the European directive and national decision related to honey. Implementation of multivariate analysis of variance (MANOVA) and LDA on specific physicochemical parameters, minerals, or their combination provided a satisfactory classification of honeys according to floral type. The overall correct classification rate (based on the cross-validation method) was 79.4% using 7 minerals and 91.2% using 8 physicochemical parameters. When the 15 parameters were combined, the classification rate of Egyptian honeys was improved by 25%.