Chemical Composition and Nutritive Value of Almond Hulls from Two Almond Varieties and Influence of Including Almond Hulls in the Diet on In Vitro Ruminal Fermentation and Methane Production.

Almond hulls (AH) are frequently used in dairy ruminant feeding, but information on variability of their nutritive value and their potential effects on CH4 production is still scarce. The influence of almond variety (Guara vs. Soleta) on chemical composition and energy value of AH was investigated using 10 samples per variety collected in 2 consecutive years. Guara-AH had greater (p ≤ 0.015) ash, protein, and fat content, but lower (p ≤ 0.001) fiber than Soleta-AH. The metabolizable energy content estimated from chemical composition and in vitro gas production was 8.5% greater for Guara than for Soleta samples. Harvesting year significantly affected most of the chemical fractions. The in vitro ruminal fermentation of diets for dairy ruminants including increasing amounts of dried AH (8, 16 and 24% of the total diet; fresh matter basis) indicated that AH can be included up to 16% of the diet, partially substituting corn, wheat bran and sugar beet pulp without detrimental effects on in vitro volatile fatty acid (VFA) production. In contrast, when AH replaced alfalfa hay and corn, VFA production was reduced at all levels of AH inclusion. No antimethanogenic effects of AH were detected in the in vitro incubations.

Use of Mediterranean By-Products to Produce Entire Male Large White Pig: Meat and Fat Quality.

A total of 70 male growing non-castrated pigs (Large White), with a 23.07 ± 2.87 kg average body weight (BW), were randomly allocated to three treatments in a 103 day trial: a CONTROL diet and two experimental diets, ALLIUM (5 g/kg of Allium spp. extract) and OLIVE (100 g/kg of olive pulp). Animals were slaughtered at 115 kg live body weight. Meat and fat quality were analyzed. Animals fed ALLIUM and OLIVE had higher water holding capacity (WHC) than those fed the control diet. No significant differences were observed between groups for cooking loss, drip losses and color CIELab. No antioxidant effect was observed on an oxygen radical absorbance capacity (ORAC) test. Animals fed OLIVE presented a more unsaturated fatty acid profile than CONTROL and ALLIUM. Meat from ALLIUM group and OLIVE showed her values of brightness and meat odor than CONTROL. Mean scores of sensory analyses (color, odor, flavor and juiciness) of cooked samples were similar for the three treatments, with the meat samples from the ALLIUM and OLIVE treatments being less hard. Consumers did not reflect a preference for any of the treatments. Both by-products could be used for pork production.

Surfactant-coated carbon nanotubes for the liquid-liquid extraction of phthalates and other migrants in virgin olive oils.

This article presents a novel application of the surfactant-coated carbon nanotubes for the joint extraction of phthalates, xylene isomers and styrene from virgin olive oils. For this purpose, two carbon nanotubes, multi-walled and single-walled carbon nanotubes, were evaluated, the former providing the better results. The target migrants were liquid-liquid extracted from the virgin olive oil samples by means of the carbon nanotube pseudophase, and the aqueous extracts were analysed by headspace-gas chromatography-mass spectrometry. Sodium chloride was added to favour the release of the analytes to the gaseous phase of the vial. The comparison of the chromatograms obtained with the direct analysis reveals a sensitivity enhancement with the use of the surfactant-coated carbon nanotubes, especially for the phthalates, which can be ascribed to the pi-pi interaction between the aromatic ring and the nanotube surface. Limits of detection were between 6 and 30 microg L(-1) for 1 mL of sample. The precision of the method was better than 7.6% and the recoveries higher than 92%. Finally, the influence of the package material and the storage conditions on the concentration of the analytes was accomplished, and it was found that the concentration of phthalates increases with time in all the packages studied, while the more volatile compounds were found to decrease under the same conditions.

Classification of extra virgin olive oils according to the protected designation of origin, olive variety and geographical origin.

A headspace-mass spectrometry (HS-MS) coupling designed for the sensory characterization and classification of extra virgin olive oil on the basis of its protected designation of origin, olive variety and geographical origin is reported. The procedure involves the headspace generation and the direct injection of the homogenized gaseous phase into a mass spectrometer through a transfer line. The results obtained were chemometrically treated to achieve the best model capable of discriminating between the different olive oil categories. For this purpose, several procedures for variables selection, data pretreatments and unsupervised techniques were evaluated. In addition, K-nearest neighbor and soft independent modeling of class analogy algorithms were employed to the classification models building. Taking into account the prediction results obtained (ca. 87% of samples correctly classified and a specificity of ca. 97%), it can be concluded than the HS-MS coupling is, with an adequate chemometric treatment, an appropriate technique for routine control.

Simple and rapid instrumental characterization of sensory attributes of virgin olive oil based on the direct coupling headspace-mass spectrometry.

A methodology for obtaining reliable qualitative and quantitative information about negative (fusty, muddy sediment, musty, rancid and vinegary) and positive (fruity) sensory attributes of virgin olive oils (lampante and extra) has been developed. The procedure implies the joint use of a headspace autosampler, a mass spectrometer and an adequate chemometric data treatment. For this purpose, soft independent modelling of class analogy (SIMCA) and partial least squares (PLS) regression approaches were used for attribute identification and quantification, respectively. InStep application was employed to generate a decision tree by the combination of both models in order to provide the joint prediction of the sensory attributes of a given virgin olive oil and their respective intensities by means of a single output result. The good prediction results obtained when the decision tree generated were applied to a new set of virgin olive oil samples (viz, a specificity of 100%, an average sensitivity of 86% and a RMSEP<0.8% in the quantification task) reveals its potential applicability in routine analysis.

Usefulness of the direct coupling headspace-mass spectrometry for sensory quality characterization of virgin olive oil samples.

The applicability of the headspace coupled to mass spectrometry for evaluation of the sensory quality of virgin olive oil samples is presented. The volatiles of the oil are directly transferred from the sample vial to the detector without chromatographic separation. The mass spectrum obtained can be considered as a fingerprint of the oil sample and can be used for classification purposes. After a training step with samples previously qualified following the official method, a classification model was created using the supervised technique soft independent modeling of class analogy (SIMCA). Eight negative (rancid, winey-vinegary, muddy sediment, hay-wood, vegetable water, earthy, fusty and musty-humidity) and three principal positive attributes (fruity, bitter and pungent) have been included in this study. With them, a classification model consisting of two main classes (extra- and lampante-virgin olive oil) was constructed. In addition, the unsupervised technique cluster analysis permitted the discrimination among oils with different negative attributes. The proposed procedure has been applied to the classification of commercial samples (as extra- or lampante-virgin olive oils) and the results were compared with those provided by the expert's panel with acceptable correlation.