Julio Nogales-Bueno

University of Seville | US

The potential of near infrared hyperspectral imaging to determine anthocyanins in intact grape has been evaluated. The hyperspectral images of intact grapes during ripening were recorded using a near infrared hyperspectral imaging covering the spectral range between 900 and 1700 nm. Reference values of anthocyanins were obtained by HPLC-DAD. A numb...

El recurso desarrollado permitirá al usuario sumergirse en un laboratorio de análisis de color real, y utilizar equipamiento de alta especialización, de gran interés, pero de difícil disponibilidad en la docencia. Un laboratorio de análisis de color cuenta con instrumentación para identificar inequívocamente y cuantificar el color de los objetos qu...

Wine color and limpidity are important aspects of consumer preferences. The alteration of these parameters can damage wine’s appearance but also its mouthfeel characteristics due to its relationship with attributes such as bitterness and astringency. Fining is a practice usually used in enology to modulate undesirable wine organoleptic attributes....

Polysaccharides are the main macromolecules of colloidal nature in wines. These compounds play a critical role in stabilizing other molecules in solution and thus modifying the wine processing and organoleptic properties. Different analytical techniques have been proposed for their determination. However, most of them are complicated and time-consu...

The Montado is a Mediterranean agro–forestry–pastoral ecosystem. Knowledge of pastures' nutritional value is critical for farm managers’ decision-making. Laboratory determinations are very expensive, destructive and costly, in terms of time and labour. The objective of this experimental work was to calibrate and validate a portable near-infrared sp...

“Persian” walnut (Juglans Regia L.) is one of the most consumed tree nuts in the world. It is rich in several bioactive compounds, with polyunsaturated and monounsaturated fatty acids (PUFA and MUFA) appearing at high concentrations. Walnut consumption protects against cardiovascular, carcinogenic, and neurological disorders. The fatty acid profile...

El video describe el análisis de laboratorio para la determinación de la cantidad de caroteno en comprimidos farmacéuticos. El método se fundamenta en la medición de la absorbancia a 450 nm de un extracto de los carotenoides presentes en el comprimido. Posteriormente, mediante el uso de la curva de calibración se calcula el contenido de carotenoide...

The Montado is an agro-silvo-pastoral ecosystem characteristic of the Mediterranean region. Pasture productivity and, consequently, the possibilities for intensifying livestock production depend on soil fertility. Soil organic matter (SOM) and phosphorus (P2O5) are two indicators of the evolution of soil fertility in this ecosystem. However, their...

Developing chemometric models from near-infrared (NIR) spectra requires the use of a representative calibration set of the entire population. Therefore, generally, the calibration procedure requires a large number of resources. For that reason, there is a great interest in identifying the most spectrally representative samples within a large popula...

After grape processing, large amounts of seeds are produced as a side product. Grape seeds are rich in proteins that could be extracted and revalorized by the wine industry due to their high techno-functional value for modulating quality features of red wines or as an alternative to the use of other stabilizers, which are also proteins but submitte...

Control of coffee quality has a great importance for being one of the most important raw materials within the international trade. The extractable composition of coffee has been studied in recent decades and the use of non-destructive methodologies is being continuously promoted. In this study, near infrared hyperspectral imaging has been applied t...

Heat stress negatively affects several physiological and biochemical processes in grapevine plants. In this work, two new methods, calorespirometry, which has been used to determine temperature adaptation in plants, and near-infrared (NIR) spectroscopy, which has been used to determine several grapevine-related traits and to discriminate among vari...

Pasture quality monitoring is a key element in the decision making process of a farm manager. Laboratory reference methods for assessing quality parameters such as crude protein (CP) or fibers (neutral detergent fiber: NDF) require collection and analytical procedures involving technicians, time, and reagents, making them laborious and expensive. T...

The influence of post fermentative addition of American barrel-shoot wastes on phenolic composition and chromatic quality of Syrah red wines has been evaluated as an environmentally sustainable alternative to the conventional winemaking for avoiding the common color loss of red wines elaborated in warm climates. American oak wood byproducts added w...

Anthocyanins in wine principally depend on grape skin extractable anthocyanin content, that is, the amount of anthocyanins present in grape skin that are released to wine during the maceration stage. This amount of extractable anthocyanins is closely linked to the cell wall degradation of skin cells. Indeed, among other methodologies, the maceratio...

Wood is an important source of phenolic compounds, which can be transferred to wine during aging process, improving its properties, from an organoleptic point of view. Therefore, understanding and optimizing the extractability of phenolic compounds from wood are crucial in the oenological field. The structural composition of oak wood samples has be...

Walnut fruit (Juglans regia L.) is an internationally well-known product with an important tradition of consumption. Its health benefits and economic importance in the food industry make this nut an interesting research topic. In this feasibility study, 200 walnut samples of 5 different varieties were collected and their near infrared (NIR) spectra...

Determining phenolic compounds of wood and its extractability to the hydroalcoholic medium is important in the oenological industry. The method proposed in this study copes with this issue in an in situ, non-destructive, and fast way. For this purpose, a number of oak by-product samples spectrally representative have been selected. Selected spectra...

There is substantial variation in levels of extractable phenolic compounds of red grapes (Vitis vinifera L.). Therefore, it could be desirable to known the aforesaid parameter at least for each vine. Nowadays, interest has shifted toward the development of portable vis/NIR systems, innovation in optical system design and miniaturization for its fri...

Near infrared hyperspectral data were collected for 200 Syrah and Tempranillo grape seed samples. Next, a sample selection was carried out and the phenolic content of these samples was determined. Then, quantitative (modified partial least square regressions) and qualitative (K-means and lineal discriminant analyses) chemometric tools were applied...

Wine color depends not only on the amount of anthocyanin present in the grapes, but also on the amount of them that may be extracted from grapes and their interactions with other phenolic compounds. Color stabilization is also specially important in poor color wines. The main goal of this study was to evaluate the effect of the addition of oak wood...

Extractable total phenolic content of American non-toasted oak (Quercus alba L.) shavings has been determined using near infrared hyperspectral imaging. A like-wine model solution was used for the simulated maceration procedure. Calibrations were performed by partial least squares regression (MPLS) using a number of spectral pre-treatments. The coe...

Near infrared hyperspectral imaging has been applied to grape seeds in order to select a representative subset of samples according to their spectral features in the 900–1700 nm range. Afterwards, selected grape seeds have been classified according to their total phenol and flavanol extractabilities. In this way, samples were sorted in three differ...

The importance of wine phenolics on the sensory characteristic of red wines is well-known. Therefore, it is necessary to control the extractability of phenolic compounds from grape skins, which depends significantly on grape ripeness and hence, on cell wall degradation. In the present study, attenuated total reflectance Fourier transform infrared (...

Hyperspectral imaging has been used to classify red grapes (Vitis vinifera L.) according to their predicted extractable total anthocyanin content (i.e. extractable total anthocyanin content determined by a hyperspectral method). Low, medium and high levels of predicted extractable total anthocyanin content were established. Then, grape skins were s...

Grape seeds were collected in ten different dates and classified in seven groups according to their individual hyperspectral imaging characteristics. Proanthocyanidin composition was studied using HPLC-MS for oligomers and acid catalyzed cleavage for polymers characterization. The combination of both analysis provided a complete description of the...

Hyperspectral imaging is an emerging and green chemistry technique for nondestructive and rapid food analysis usually carried out in either the visible-short near infrared (vis-NIR; 400-1000 nm) or near infrared (NIR; 1000-1700 nm) spectral regions. Winemakers are continuously looking for high quality wines and the major factors impacting on wine q...

Background Anthocyanins are the main responsible for the colour of red wines and therefore it may be important to evaluate the content of the aforesaid secondary metabolites during grape ripening due to the crucial importance to determine wine colour. Nowadays, there is a growing demand of rapid and non-destructive analytical tools for analysing gr...

Characteristic vector analysis has been applied to near infrared spectra to extract the main spectral information from hyperspectral images. For this purpose, 3, 6, 9 and 12 characteristic vectors have been used to reconstruct the spectra and root mean square errors (RMSE) have been calculated to measure the differences between characteristic vecto...