A. M. Giuffre

HPLC-DAD detection of changes in phenol content of red berry skins during grape ripening

With increasing concern for a demand from consumers for natural products, there is a wide interest in bioactive substances. The new frontier of dietary quality is the study and promotion of functional foods. Phenols are among the most important functional molecules. Red grape and red wine contain bioactive products as phenols. Changes occurring in the concentrations of phenols, such as hydroxycinnamic tartaric acids (hctas), flavonols, and anthocyanins in berry skins, were measured during growth and ripening of four red grape cultivars, Alicante, Black Malvasia, Nerello, and Prunesta (Vitisvinifera L.), cultivated in a coastal location of the Reggio Calabria Province (Southern Italy). These cultivars are the most popular and are considered to be the most suitable grape cultivars for cultivation in the Tyrrhenian side of the Reggio Calabria Province. Fractioning of three phenolic classes was conducted through the adsorbing resin Serdolit XAD-2. Each single phenolic fraction was analyzed by liquid chromatography with diode array detector (HPLC-DAD). Each cultivar presented a different chromatographic profile particularly for anthocyanins. The cultivar Nerello was distinguished from other for its high content of anthocyanins. The rate, at which the concentration of hctas, flavonols and anthocyanins increased, varied greatly among the cultivars. The hydroxycinnamic tartaric acid profile varied in the studied cultivars, in fact in Alicante, Black Malvasia and Prunesta cultivars, the predominant was trans-coumaroyl tartaric acid, while in Nerello cultivar, trans-caffeoyl tartaric acid was the most abundant. In addition, the results showed that amounts of phenolic compounds contained in grape skin changed throughout the grape ripening process.

Optimization of a Solid-Phase Microextraction method for the Gas Chromatography-Mass Spectrometry analysis of blackberry (Rubus ulmifolius Schott) fruit volatiles

A Solid-Phase Microextraction method for the Gas Chromatography-Mass Spectrometry analysis of blackberry (Rubus sp.) volatiles has been fully optimized by means of a Box-Behnken experimental design. The optimized operating conditions (Carboxen/Polydimethylsiloxane fiber coating, 66°C, 20 min equilibrium time and 16 min extraction time) have been applied to the characterization for the first time of the volatile composition of Rubus ulmifolius Schott blackberries collected in Italy and Spain. A total of 74 volatiles of different functionality were identified; esters and aliphatic alcohols were the predominant classes in both sample types. Methylbutanal (2.02-25.70%), ethanol (9.84-68.21%), 2,3-butanedione (2.31-14.71%), trans-2-hexenal (0.49-17.49%), 3-hydroxy-2-butanone (0.08-7.39%), 1-hexanol (0.56-16.39%), 1-octanol (0.49-10.86%) and methylbutanoic acid (0.53-21.48%) were the major compounds in most blackberries analyzed. Stepwise multiple regression analysis of semiquantitative data showed that only two variables (ethyl decanoate and ethyl acetate) were necessary for a successful differentiation of blackberries according to their harvest location.

Determination of organophosphorus insecticides in edible oils and fats by splitless injection of the oil into a gas chromatograph (injector-internal headspace analysis)

ZusammenfassungDirekte Einspritzung von Öl oder Fett in einen mäßig heißen Injektor des Gaschromatographen erlaubt eine Art Headspacetechnik im Verdampfungsinjektor: Öl oder Fett wird 1∶1 mit Aceton verdünnt und bei 200 °C eingespritzt. Die Komponenten, z. B. Phosphorsäureester-Insektizide, verdampfen aus dem Ölfilm auf der Röhrchenwand und werden splitlos in die Säule übertragen. Das Öl fließt langsam der Wand entlang nach unten und wird in einer Art Tasche aufgefangen. Mit flammenphotometrischer Detektion liegt die Nachweisgrenze unter 10 μg/kg.AbstractDirect injection of oil or fat into a moderately heated injector enables performance of a kind of head-space technique in, the injector: oil or fat is diluted 1∶1 with acetone and injected into a vaporizing chamber at 200° C. Components, for example organophosphorus insecticides, evaporate from the oil film on the insert wall and are transferred into the column in the splitless mode; the oil slowly flows along the wall to the bottom of the insert and is retained there in a kind of a bag. Using a flame photometric detector, detection limits are below 10 μg/kg.

Statistical analysis for improving data precision in the SPME GC-MS analysis of blackberry (Rubus ulmifolius Schott) volatiles

Statistical analysis has been used for the first time to evaluate the dispersion of quantitative data in the solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis of blackberry (Rubus ulmifolius Schott) volatiles with the aim of improving their precision. Experimental and randomly simulated data were compared using different statistical parameters (correlation coefficients, Principal Component Analysis loadings and eigenvalues). Non-random factors were shown to significantly contribute to total dispersion; groups of volatile compounds could be associated with these factors. A significant improvement of precision was achieved when considering percent concentration ratios, rather than percent values, among those blackberry volatiles with a similar dispersion behavior. As novelty over previous references, and to complement this main objective, the presence of non-random dispersion trends in data from simple blackberry model systems was evidenced. Although the influence of the type of matrix on data precision was proved, the possibility of a better understanding of the dispersion patterns in real samples was not possible from model systems. The approach here used was validated for the first time through the multicomponent characterization of Italian blackberries from different harvest years.

Policosanol in Tomato (Solanum lycopersicum L.) Seed Oil: the Effect of Cultivar

Soxhlet-petroleum ether extraction was used to obtain oil from tomato seeds. Three tomato cultivars from South Italy (Principe Borghese, Rebelion F1 and San Marzano) were studied. Policosanol is a mixture of long chain linear fatty alcohols (n-alkanols), its content and composition was found to be highly significantly influenced by cultivar. Seven fatty alcohols were detected: docosanol (C22-ol), tricosanol (C23-ol), tetracosanol (C24-ol), pentacosanol (C25-ol), hexacosanol (C26-ol), heptacosanol (C27-ol) and octacosanol (C28-ol). The highest policosanol content was found in Principe Borghese 71.88 mg/Kg. Octacosanol was the linear alcohol present in highest quantity, i.e. 38-42% of the total linear alcohols detected in tomato seed oils (TSO). Chemometrics was applied to study the differences among cultivars. The sum of even long chained fatty alcohols was always more than 95% of the total policosanol content. One-way ANOVA and principal component analysis well differentiated the three cultivars.

Seed Oil from Ten Algerian Peanut Landraces for Edible Use and Biodiesel Production

As a result of a recent ad hoc prospection of the Algerian territory, a collection of peanut (groundnut; Arachis hypogaea L.) landraces was established, covering a remarkable array of diversity in terms of morphological and physiological features, as well as of adaptation to local bioclimatic conditions. In the present work, the oils extracted from the seeds of these landraces were evaluated in terms of edible properties and suitability for biodiesel production. As for edible use, a low free acidity (ranging from 0.62 to 1.21%) and a high oleic acid content (44.61-50.94%) were common features, although a poor stability to oxidation [high peroxide values, high spectrophotometric indices, and low % of inhibition in the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH)· test] was observed in a few cases. As for biodiesel production, low values of acidity [1.23-2.40 mg KOH (g oil)(-1)], low iodine values [90.70-101.54 g I2 (g oil)(-1)], high cetane numbers (56.95-58.88) and high calorific values (higher heating value 37.34-39.27 MJ kg(-1)) were measured. Edible properties and suitability for biodiesel production were discussed with respect to the German standard DIN 51605 for rapeseed oil and to the EN 14214 standard, respectively. One way ANOVA and Hierarchical Cluster Analysis showed significant differences among the oils from the Algerian peanut landraces.

Physico-chemical stability of blood orange juice during frozen storage

ABSTRACT Blood orange juice from Citrus sinensis (L.) Osbeck cv. Moro was compared to a concentrated blood orange juice and both juices were studied during frozen storage at −20°C. Analyses were conducted on pH (3.33–3.81) and titratable acidity as citric acid (11.14–13.16 g/L). The formol number decreased in both blood orange juice and concentrated blood orange juice during frozen storage, while vitamin C showed a very slight decrease. Scavenging abilities of the juices for the DPPH∙ radical ranged from 53.39% to 42.55% in blood orange juice and from 39.16% to 33.75% in concentrated blood orange juice during frozen storage. Although anthocyanins showed a diminution during storage in both the concentrated and non-concentrated blood orange juice, they were always higher in the non-concentrated juice fruit. Four phenolic acids were detected: gallic, chlorogenic (the highest quantity, 13–27 mg/L), caffeic, and ferulic, the latter showed the lowest content. Ten flavonoids were identified, two flavonols (rutin and quercetin) and eight flavanones: narirutin (the second highest flavonoid), naringin, hesperidin (the highest quantity), neoeriocitrin, didymin, eriocitrin, neohesperidin, and hesperetin. Concentration and duration of frozen storage were found to influence the physicochemical properties of blood orange juice in different ways.