Mircea Oroian

Antioxidants: Characterization, natural sources, extraction and analysis

Recently many review papers regarding antioxidants from different sources and different extraction and quantification procedures have been published. However none of them has all the information regarding antioxidants (chemistry, sources, extraction and quantification). This article tries to take a different perspective on antioxidants for the new researcher involved in this field. Antioxidants from fruit, vegetables and beverages play an important role in human health, for example preventing cancer and cardiovascular diseases, and lowering the incidence of different diseases. In this paper the main classes of antioxidants are presented: vitamins, carotenoids and polyphenols. Recently, many analytical methodologies involving diverse instrumental techniques have been developed for the extraction, separation, identification and quantification of these compounds. Antioxidants have been quantified by different researchers using one or more of these methods: in vivo, in vitro, electrochemical, chemiluminescent, electron spin resonance, chromatography, capillary electrophoresis, nuclear magnetic resonance, near infrared spectroscopy and mass spectrometry methods.

Optimization of ultrasound-assisted extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant (Solanum melongena L.) peel.

The present study describes the extraction of total monomeric anthocyanin (TMA) and total phenolic content (TPC) from eggplant peel using ultrasonic treatments and methanol and 2-propanol as extraction solvents. The extraction yields were optimized by varying the solvent concentration, ultrasonic frequency, temperature and time of ultrasonic treatment. Box-Behnken design was used to investigate the effect of process variables on the ultrasound-assisted extraction. The results showed that for TPC extraction the optimal condition were obtained with a methanol concentration of 76.6%, 33.88 kHz ultrasonic frequency, a temperature of 69.4 °C and 57.5 min extraction time. For TMA the optimal condition were the following: 54.4% methanol concentration, 37 kHz, 55.1 °C and process time of 44.85 min.

Multi-element composition of honey as a suitable tool for its authenticity analysis.

Abstract The aim of this study was to evaluate the composition of 36 honey samples of 4 different botanical origins (acacia, sun flower, tilia and honeydew) from the North East region of Romania. An inductively coupled plasma-mass spectrometry (ICP-MS) method was used to determine 27 elements in honey (Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Tl, U, V and Zn). We would like to achieve the following goal: to demonstrate that the qualitative and quantitative multi-element composition determination of honey can be used as a suitable tool to classify honey according to its botanical origin. The principal component analysis allowed the reduction of the 27 variables to 2 principal components which explained 74% of the total variance. The dominant elements which were strongly associated with the principal component were K, Mg and Ca. Discriminant models obtained for each kind of botanical honey confirmed that the differentiation of honeys according to their botanical origin was mainly based on multi-element composition. A correct classification of all samples was achieved with the exception of 11.1% of honeydew honeys.

Chemical composition and temperature influence on the rheological behaviour of honeys

The purpose of this work was to examine the viscoelastic properties of Spanish honeys with various sugar contents [fructose (32–42 g/100 g honey), glucose (24–35 g/100 g honey), sucrose (0.0–3.4 g/100 g honey)]; concentrations (79–83 °Brix), and moisture levels (16–19 g/100 g honey) at different temperatures (5, 10, 15, 20, 25, 30, and 40°C). Honey showed Newtonian behaviour, presenting a highly viscous part (loss modulus was much greater than the elastic modulus). The loss modulus (G″) and viscosity increased with moisture content and a decrease with temperature. Exponential and power law models were applied to fit loss modulus and viscosity data. Polynomial models were proposed to describe the combined effect of temperature, fructose, glucose, sucrose content, other sugars, non-sugar substance, and moisture content.

Honey authentication based on physicochemical parameters and phenolic compounds

The honeys analysed were authenticated using physicochemical parameters and phenolics.The physicochemical parameters and phenolics have been evaluated for the 51 honey samples.Honey classification has been made PCA, LDA and ANN. The aim of this study is to assess the usefulness of physicochemical parameters (pH, water activity, free acidity, refraction index, Brix, moisture content and ash content), color parameters (L, a, b, chroma, hue angle and yellow index) and phenolics (quercetin, apigenin, myricetin, isorhamnetin, kaempherol, caffeic acid, chrysin, galangin, luteolin, p-coumaric acid, gallic acid and pinocembrin) in view of classifying honeys according to their botanical origin (acacia, tilia, sunflower, honeydew and polyfloral). Thus, the classification of honeys has been made using the principal component analysis (PCA), linear discriminant analysis (LDA) and artificial neural networks (ANN). The multilayer perceptron network with 2 hidden layers classified correctly 94.8% of the cross validated samples.

Classification of unifloral honeys using multivariate analysis

The aim of this study was to investigate the physicochemical properties (moisture content, conductivity, 5-HMF, fructose, glucose, L*, a* and b* color parameters) and volatile compounds of Romanian honeys. According to the melissopalynological analysis, the honey samples were of the following botanical origins: acacia, sunflower and tilia. Liquid–liquid extraction followed by GC-MS analysis was used to study the volatile fraction. The volatile compounds of the three types of honeys are given by a total number of forty-five compounds of different chemical groups (aldehydes, alcohols, acids, ketones, organo-sulphur compounds, terpenes, hydrocarbons, esters and furan compounds). The physicochemical properties and volatile compounds data of the fifty samples analyzed were subjected to cluster analysis (CA), principal component analysis (PCA) and stepwise discriminant analysis (SDA). The classification of honeys according to their botanical and geographical origin was made using the physicochemical properties and volatile compounds with percentages higher than 80%.

Patulin in apple juices from the Romanian market

The aim of this study was to determine patulin levels in apple-based juices from the Romanian market and to establish a health risk assessment. For this purpose, 50 samples of apple-based juices have been purchased from the Romanian market. Aliquots were extracted by liquid–liquid extraction using ethyl acetate, analysed and quantified using a high-performance liquid chromatography (HPLC) method. The patulin level in the apple juices from Romania ranged between <0.7 μg/l and 101.9 μg/l. In 6% of the 50 samples analysed, the maximum limit for patulin as set by the European Union (50 μg/l) was exceeded.

Heavy Metals Profile in Honey as a Potential Indicator of Botanical and Geographical Origin

The aim of this study was to determine the heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) from honeys (acacia, sunflower, tilia, and polyfloral) from different counties (Suceava, Botosani, and Vaslui) of the northeast region of Romania. The data were analyzed using principal component analysis and linear discriminate analysis in order to achieve useful models for classification of honeys according to their botanical and geographical origin using the heavy metals content. The heavy metals content can be used as a suitable tool for the classification of honeys according to their botanical origin (80.8% were correctly classified), but not for the geographical origin (only 21.2% were correctly classified). None of the 10 heavy metals analyzed exceeded the maximum allowable level.

Acrylamide in Romanian food using HPLC-UV and a health risk assessment

The aim of this study was to investigate the level of acrylamide from coffee, potato chips and French fries in Romanian food. According to the European Food Safety Authority, coffee beans, potato chips and French fries have the highest levels of acrylamide. For this survey, 50 samples of coffee beans, 50 samples of potato chips and 25 samples of French fries were purchased from different producers from the Romanian market. Acrylamide levels have been quantified using high-performance liquid chromatography with a diode array detector (HPLC-DAD) method, using water as mobile phase. Health risk assessment was achieved by computing the average daily intake, hazard quotient, cumulative risk, carcinogenic risk and cancer risk. For coffee, potato chips and French fries, acrylamide was not shown to pose a health risk in Romanian food.

Botanical authentication of honeys based on Raman spectra

The aim of this study was to investigate the possibility of honey botanical authentication using the Raman spectroscopy. For this purpose 76 samples of honeys of different botanical origins (acacia, tilia, sunflower, polyfloral and honeydew) were purchased from local beekeepers from Suceava county, Romania. The honey samples have been characterized based on the melissopalynological analysis and electrical conductivity according to its botanical origin. The samples have been classified into acacia, tilia, sunflower, polyfloral and honeydew. The Raman spectra analysis has been proved to be an excellent tool (simple, rapid and non destructive method) for honey authentication; by the linear discriminant analysis (LDA) applied 83.33% of the honey has been correctly cross validated.