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Phenolic compounds have a strong influence on the quality and authenticity of grapes, and they have been the main objective of several studies due to its importance on the structure, flavour and co...

Grape seed flour by-product (GSBP) is an economic and renewable source of proteins, increasingly being explored due to interesting technological application such as colour protection in rich-anthocyanins beverages. Globulin-like proteins from GSBP were characterised by proteomic and computational studies. MALDI TOF/TOF analysis revealed the presence of two 11S globulins (acid and basic), whose 3D structures have been elucidated for the first time in Vitis vinifera L. grape seeds by using homology models and molecular dynamics. The secondary structure showed 11 α-helices and 25 β-sheets for acid and 12 α-helices and 24 β-sheets for basic 11S globulins. Molecular docking results indicate that both grape seed 11S globulins could establish different types of non-covalent interactions (π-π) with malvidin 3-O-glucoside (wine anthocyanin), which suggest a possible colour protection similar to that occurring in copigmentation phenomenon. These findings provide valuable information of globulin family proteins that could be relevant in food industry applications. España Ministerio de Economía y Competitividad (Project AGL2017- 84793-C2 and FPI grant PRE2018-087184) Programa Operativo FEDER 2014-2020/Consejería de Economía y Conocimiento de la Junta de Andalucía (Project US-1261752)

El objetivo de esta innovación fue mejorar el aprendizaje en conceptos de metabolismo energético a través de ejercicios de autoevaluación por parte de los alumnos. El ciclo de mejora en el aula (CIMA) se llevó a cabo en los seminarios de la asignatura Nutrición y Bromatología, impartida en el 3er curso del Grado en Farmacia de la Universidad de Sevilla. Para aplicar el CIMA, se les propuso a los alumnos una serie de actividades durante el transcurso de las clases donde te- nían que realizar un estudio personal del gasto energético total (GET), así como del aporte de nutrientes ingeridos en su dieta. Por otro lado, y durante la parte teórica de las asignaturas, se pusieron en práctica las estrategias docentes ad- quiridas en el curso de innovación docente, como el uso de mapas de contenidos y la evaluación del éxito del CIMA a través de cuestionarios. Palabras clave: Nutrición y bromatología, farmacia, desarrollo profesional do- cente, metabolismo energético.

Bee pollen (BP) is a natural product with remarkable nutritional and bioactive composition. Some of the compounds of interest are carotenoids with provitamin A activity, possessing an excellent antioxidant capacity and positive health effects. For that, the objective of this work was to characterize the botanical origin and carotenoid profile in two particle sizes of Colombian BP by Rapid Resolution Liquid Chromatography (RRLC). The carotenoid profile and α-tocopherol content were obtained, and ANOVA analysis was employed to explore data. The main carotenoids found were 9Z-zeaxanthin (65.15 ± 7.41–1104.98 ± 113.41 μg/g pollen), zeaxanthin (35.29 ± 2.08–354.30 ± 29.91 μg/g pollen), two zeaxanthin isomers (18.23 ± 3.73–227.69 ± 19.00 μg/g pollen) and β-cryptoxanthin (8.67 ± 1.27–34.25 ± 2.25 μg/g pollen). The statistical analysis showed significant differences between harvest time and particle size, proving the influence of climatic and botanic factors. The high content of macular and provitamin carotenoids was highlighted, which proposes BP as a significant source of important bioactive compounds. The carotenoids found allows characterizing BP in a complete seasonal cycle (January–December), research conducted for the first time in this product. Also, the information reported can be used to select harvest time of BP in order to include it as an ingredient, supplement, or raw material in the food industry, according to the carotenoid composition needed.

The usefulness of digital image analysis in estimating sensory attributes of grape seeds in relation to maturation level was evaluated for the first time. Seeds from Syrah grapes harvested throughout the ripening period were grouped according to maturity using the DigiEye® system. The discriminant ability, homogeneity, repeatability, and uniformity of a sensory panel were assessed after training on grape seeds. The aim was to evaluate the use of digital image techniques in order to accurately establish the maturity level of grape seeds, based on sensory and textural features. All sensory attributes (color, hardness, cracking, vegetal, bitterness and astringency) showed significant (p &lt, 0.05) correlations with the chemical maturity stage. Color and vegetal (sensory attributes), together with deformation energy (instrumental texture parameter) (De), allowed for the classification of the seeds into four real maturity stages, hence their usefulness as grape seed ripening indicators. Significant (p &lt, 0.05) and high-correlation factors were also found between instrumental and sensory attributes. Therefore, digital analysis can be a useful tool to better define the maturity stage in the vineyard, and to dispose of grape seeds with well-defined sensory profiles for specific oenological applications. This could help to determine the optimal harvest date to manage winemaking, in order to produce high quality wines in warm climates.

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 population set. In this study, principal component and hierarchical clustering analyses have been compared for their ability to provide different representative calibration sets. The calibration sets generated have been used to control the technological maturity of grapes and total phenolic compounds of grape skins in red and white cultivars. Finally, the accuracy and precision of the models obtained with these calibration sets resulted from the application of the selection algorithms studied have been compared with each other and with the whole set of samples using an external validation set. Most of the standard errors of prediction (SEP) in external validation obtained from the reduced data sets were not significantly different from those obtained using the whole data set. Moreover, sample subsets resulting from hierarchical clustering analysis appear to produce slightly better results. Universidad de Sevilla- becas VPPI-II.2 y VPPIII.4 Ministerio de Ciencia e Innovación del gobierno español-Contrato Juan de la Cierva FJC2018 037967 I Ministerio de Economía y Competitividad del gobierno español-AGL2017-84793-C2 Consejería de Economía y Conocimiento de la Junta de Andalucía-US-1261752

Overripe seeds from sun-dried grapes submitted to postharvest dehydration constitute a scarcely investigated class of vinification byproduct with limited reports on their phenolic composition and industrial applications. In this study, Raman spectroscopy was applied to characterize a selection of overripe seed byproducts from different white grapes (cv. Moscatel, cv. Pedro Ximénez and cv. Zalema) submitted to postharvest sun drying. The Raman measurements were taken using a 1064 nm excitation laser in order to mitigate the fluorescent effect and the dispersive detection scheme allowed a compactness of the optical system. Spectroscopic data were processed by a prin-cipal component analysis to reduce the dimensionality and partner recognition. The evolution of the Raman spectrum during the overripening process was compared with the phenolic composition of grape seeds, which was determined by rapid resolution liquid chromatography/mass spectrom-etry (RRLC/MS). A multivariate processing of the spectroscopic data allowed the classification of overripe seeds according to the grape variety and the monitoring of stages of the postharvest sun drying process. Ministerio de Economía y Competitividad AGL2017-84793 Universidad de Sevilla SOL2019-12566

Bee pollen is a hive product, resulting from floral pollen agglutination by worker bees and it is characterized by its excellent bioactive and nutritional composition. Currently, research is focused on bee pollen applications on food industry, because this product has been considered an excellent source of compounds for human nutrition. It is also important in some industries, where color and particle size are important characteristics for production. Due to the granular nature of bee pollen, conventional colorimetry does not allow describing color correctly; thus, digital image analysis is a better alternative. This technique could also allow classifying bee pollen according to its appearance beyond the color. Consequently, the aim of this work was to develop a novel methodology for image data processing to classify bee pollen as ingredient in food industry. Seven color groups in samples were established regarding harvest month and particle size. It was possible to calculate the percentage of each color group in all samples. This methodology also allowed selecting each fraction for different applications in food industry using colorimetry, granulometry and the relationship between both of them.

A hyperspectral imaging (HSI) system (380–1000 nm) was investigated for non-invasively estimating adenosine triphosphate (ATP) content in ready-to-eat sausages during 5 days storage at 35 °C. A set of pretreated combinations were carried out on preprocessing the spectra to improve the performance of partial least squares regression (PLSR). According to the regression coefficient values, ten important wavelengths (385, 390, 395, 505, 580, 670, 745, 780, 855, and 955 nm) were selected in this study. PLSR models developed using full wavelengths and optimal wavelengths showed the prediction coefficient of determination (rp2) up to 0.8324 and 0.8606, respectively. The concentration and location of the ATP content in sausages were for the first time displayed via chemical imaging developed by R statistics. Combining HSI and multivariate analysis can quantify and visualize ATP dynamic changes during storage and a great potential in the processed meat industry for real-time inspection.

Redness can greatly influence the freshness of sausages. A precise, rapid and noncontact analytical method or tool is needed to quantify the color. Hyperspectral imaging (HSI) is an emerging technique that integrates spectroscopy and imaging to obtain the spectral and spatial information simultaneously. In the present study, the redness of cooked sausages stored up to 57 days was predicted using HSI in tandem with multivariate data analysis. The mean spectra of the sausages were extracted from the hyperspectral images. Partial least squares regression (PLSR) and forward stepwise multiple regression (FSMR) models were used to develop the relavent spectral profiles with the redness of the cooked sausages.; Results: Ten important wavelengths were selected based on the regression coefficient values from the PLSR model. The PLSR model established using the full wavelengths presented a good performance, with Rc of 0.934 and a root mean square error of calibration of 0.642 (redness ranged between 14.99 and 21.48). The prediction maps for demonstrating evolution of redness in sausages were developed for the first time using R statistics (R Foundation for Statistical Computing) and Matlab (MathWorks Inc., Natick, MA, USA).; Conclusion: HSI combined with PLSR and FSMR can be used to quantify and visualize evolution of sausage redness under different storage days. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

Two locally grown wheat species named Triticum aestivum L. and Triticum vulgare L. were studied for their phytochemical contents and their biological activities. T. vulgare presented the highest amounts of total phenolic compounds and ascorbic acids while T. aestivum was found to be rich in flavonoids, flavonols, proanthocynidins and ortho -diphenols. Eleven carotenoids were identified in T. vulgare where the most dominant compounds belongs to α-carotene and its derivatives while T. aestivum presented seven carotenoids. This later presented the highest DPPH radical scavenging activity and exhibited a strong reducing power in FRAP, phosphomolybdenum, hydrogen peroxide and reducing power assays. T. vulgare extract was found to be effective in metal chelating power and in scavenging nitric oxide radical. No significant differences in scavenging ABTS and hydroxyl radicals were noted between the two wheat species. T. aestivum inhibited xanthine oxidase and ROS production and showed the best cytotoxic effect while T. vulgare extract exhibited anti-calpain activity.

The color of the food can be evaluated visually or instrumentally. The instrumental measurement allows to measure the color objectively and can be carried out by different techniques, most of them fast, cheap, and simple. Carotenoids are responsible for the color of many plants and foods. The measurement of color can be an effective tool to determine indirectly the concentration of carotenoids in plants and foods. In this chapter, we describe both traditional and recent methodologies for color measurement.

Imaging techniques have revolutionised the way quality is assessed in food products. Using cameras, it is possible to estimate not only the chemical composition of a product but also its geometric distribution. However, the limited range of detectors implies the use of different measuring equipment. The presence of small and discrete samples or very heterogeneous samples makes joining both sets of data a complicated task. This work arises from the need to merge images with colour information and NIR spectral information on grape samples and derivatives. An application has been created under MATLAB to join this type of images so that it is possible to simultaneously extract the colour and/or spectral information of each pixel or object present in the image. Although the software can be used in a wide range of applications, it has been successfully applied to grape and grape seed samples. In red grape bunches, it was possible to evaluate individually grapes and notice differences due to changes in visible and infrared regions at the same time. In the case of white grape seeds, it was proved that merged images were better to discriminate between varieties than the single CIELAB or spectral images.

Spanish MINECO grant BES-2012-060192 Spanish MINECO project AGL2014- 58486-C2 Universidad de Sevilla (España) Plan VI (VPPI-US)

Phenolic composition, colour and morphology variables were monitored during ripening in grape seeds of Vitis vinifera L. cv. Tempranillo in 2010. The aim of the study was to determine the effect of limitation induced by early leaf removal (ELR) vs. non-defoliated (ND) control vines. The ultimate goal of this research was to assess whether phenolic composition could be predicted based on variables obtained by image analysis. ELR advanced grape maturity also had lower phenolic concentration and smaller and darker seeds. (+)-Catechin and total cinnamic acid contents as well as L* and aspect ratio were the most significant parameters for distinguishing treatments. Furthermore, area, length, width, L*, a*, b* and heterogeneity predict the phenolic composition in grape seeds. Although it is not yet a substitute for chemical analysis, it could become a quick way to estimate the phenolic composition of grape seeds during maturation. The methodology proposed in this work could be a powerful tool for winemakers.

This chapter discusses the detection of fish freshness, evaluation of physical properties and chemical composition and inspection of microbial spoilage in fish by Hyperspectral imaging (HSI). Fish has been one of the most important components of several and nutritious diets in the world. Its contribution to human health is well documented, being an essential topic for researchers. Compared with traditional methods, HSI is a environmental friendly, toxic-free, noninvasive, time-saving technique. Fillets of cod under different programs of freezing, thawing, and storage were investigated by HSI. The blood in whitefish fillets was detected by HSI with a range of 430–1,000 nm. Significant efforts have been made by the industries to enhance the quality and safety of the aquatic and seafood products by using new technologies such as novel cooling. However, high-quality and safe fish products are also closely related to human health and dietary benefits.

Background and Aims Winemaking generates a large quantity of grape marc that causes environmental and economic problems, which could be minimised by exploiting and adding value to these by-products. Marc is composed of seeds, skins and stems that are an important source of phenolic substances, which have antioxidant properties and potential benefits to human health. It is necessary to develop novel methods for assessing the composition of marc because conventional analyses are destructive and require lengthy preparation procedures and chemical reagents. Methods and Results Near-infrared hyperspectral imaging has been used for evaluating 27 individual phenolic substances in the components of grape marc after freeze-drying, the only sample preparation step. By applying partial least squares regression to the spectral data, values of R2 up to 0.98 were obtained even for estimating some minor compounds. Conclusions This methodology arises as an attractive alternative to analyse the phenolic composition of grape marc because of its speed and simplicity. Significance of the Study The use of this technique will allow wine producers to quickly determine the phenolic composition and decide the destination of this by-product.

BACKGROUND:Anthocyanins are the main compounds responsible for the colour of red wines and therefore itmay be important to evaluate the contentof the aforesaid secondary metabolites duringgraperipeningdueto the crucial importance to determine wine colour. Nowadays, there is a growing demand of rapid and non-destructive analytical tools for analysing grapes, such as the emerging hyperspectral analysis. RESULTS: The hyperspectral images of intact grapes (Vitis vinifera L. cv. Tempranillo, Graciano, Garnacha and Mazuelo red grape from vineyards located in the D.O.Ca. Rioja at two different developmental stages) were recorded using a near infrared hyperspectral imaging device (900–1700 nm). Reference values of anthocyaninswere obtained by HPLC-DAD. Calibrationswere performed by modified partial least squares regression and present a good potential (coefficient of determination of 0.72 and standard error of cross-validation values of 0.78 and 0.70mg per grape for total and non-acylated anthocyanins respectively). CONCLUSION: The procedure reported here presents a good potential for a fast and reasonably inexpensive screening of these compounds in intact single berries. Moreover, the heterogeneity of anthocyanins within the same ripeness stage could be evaluated using this non-detructive tool.

Three independent methodologies were investigated to achieve the differentiation of red grapes from different grape varieties (Garnacha, Graciano, Mazuelo and Tempranillo) collected from five vineyards located in the D.O.Ca. Rioja. Anthocyanin chromatographic analysis, color image analysis and near infrared hyperspectral imaging were carried out for the grapes. Then, a Stepwise Linear Discriminant Analysis (SLDA) was developed for each data set in order to discriminate grapes according to their grape variety. As a result, using anthocyanin profile, color image analysis and near infrared hyperspectral imaging respectively, 88%, 54% and 100% of the samples were correctly classified in the internal validation process and 86%, 52% and 86% were correctly classified in the leave-one-out cross-validation process

The effect of salt stress (200 mM NaCl for 28 days) on physiological characteristics of Hibiscus rosa-sinensis, such as abscisic acid (ABA) content, electrolyte leakage, and photochemical efficiency in leaves, and its influence on biomass production, anthocyanin composition, and color expression of flowers were evaluated. Salinity significantly increased electrolyte leakage and ABA content in leaves and reduced the flower fresh weight. Chlorophyll fluorescence parameters were lower in salt stress condition, compared to control. Moreover, salt stress negatively affected the content of anthocyanins (mainly cyanidin-3-sophoroside), which resulted in a visually perceptible loss of color. The detailed anthocyanin composition monitored by HPLC-DAD-MS and the color variations by digital image analysis due to salt stress showed that the effect was more noticeable at the basal portion of petals. A forward stepwise multiple regression was performed for predicting the content of anthocyanins from appearance characteristics obtained by image analysis, reaching R-square values up to 0.90.

Hyperspectral images of intact grapes during ripening were recorded using a near infrared hyperspectral imaging system (900-1700 nm). Spectral data have been correlated with grape skin total phenolic concentration, sugar concentration, titratable acidity and pH by modified partial least squares regression (MPLS) using a number of spectral pre-treatments and different sets of calibration. The obtained results (RSQ and SEP, respectively) for the global model of red and white grape samples were: 0.89 and 1.23 mg g-1 of grape skin for total phenolic concentration, 0.99 and 1.37 Brix for sugar concentration, 0.98 and 3.88 g L-1 for titratable acidity and for pH 0.94 and 0.12. Moreover, separate calibration models for red and white grape samples were also developed. The obtained results present a good potential for a fast and reasonably inexpensive screening of these parameters in intact grapes and therefore, for a fast control of technological and phenolic maturity. Ministerio de Ciencia e Innovación BES-2012-060192, BES-2009-025429, JCI-2011-09201, AGL2011-30254-C02 Junta de Andalucía P10-AGR6331

Graphical abstractDisplay Omitted The method for evaluating heterogeneous colours in foodstuffs has been improved.An algorithm that adjusts point clouds to ellipsoids in CIELAB colour space has been introduced.The methodology presented can be useful in studies that use 'Chemical Imaging'. The use of computer vision for estimating composition in food products has become wide spread in recent years, especially for products where by measuring colour or other spectral features, we are able to estimate the composition, variety, or ripeness. On the other hand, the appearance is one of the most worrying issues for producers due to its influence on quality and consumer preferences. Computer vision is the best option to satisfy the need of measuring colour and heterogeneity in these products. Previous studies have expressed the heterogeneity with the standard deviation or other magnitudes that do not explain accurately the distribution of colour in CIELAB colour space. Graphing the scatterplot of the a*b* values belonging to the pixels of the image helps to explain the shape of the point cloud, but currently there is not an objective procedure to quantify these point clouds. This work has established a method for improving the illustration of colour measurements by image analysis. The proposed algorithm classified the point clouds by clustering methods and established the methodology for fitting the resulting clusters into ellipsoids. Their geometric features described the shape of the clouds in a quantitatively manner and they could be useful in multivariate statistical techniques for classifying and predicting chemical properties.

Ficus carica L., Ceratonia siliqua L. and Quercus ilex L. are natural products that are used as an advantageous rich source of bioactive compounds of high economic value because of its use in cosmetic, pharmaceutical and agriculture industries. These crops were studied for its phytochemical contents and were investigated for antioxidant activities and its effects on reactive oxygen species (ROS) production, calpain activity and antiproliferative effects. Results showed that extremely high total contents of phenolics, flavonoids and ortho -diphenols were detected in Quercus ilex , while proanthocyanidin level was higher in Ficus carica. Ceratonia siliqua pods showed more carotenoids and had the highest lightness value (L*). Quercus ilex and Ceratonia siliqua extracts were very effective in scavenging free radicals. The best hydroxyl radical scavenging activity was attributed to Quercus ilex with 80.51 ± 0.20% while nitric oxide assay showed no significant differences between extracts. Ficus carica presented a higher reducing ability with 638.23 ± 0.43 mg gallic acid equivalents/100 g, while Quercus ilex was very potent in reducing power assays. Percentages of metal chelating capacities of Quercus ilex and Ficus carica extracts were 87.87 ± 0.34 and 73.17 ± 0.16%, respectively. These two samples were also able to scavenge hydrogen peroxide efficiently. At 250 μg/mL , Quercus ilex presented the best xanthine oxidase inhibition, 89.81 ± 0.36%. Ceratonia siliqua and Quercus ilex extracts presented the best capacities of ROS inhibition and reduced cell viability in a concentration dependent manner. All samples decreased calpain activity. These extracts could be further exploited as a source of natural products with antioxidant and anticancer effects.

Tomatoes ( Solanum lycopersicum L .) are food staples that contain high levels of lycopene (LYC), a red carotenoid thought to provide health benefits. Previous studies indicate that instrumental color measurements can be harnessed to estimate carotenoid levels in a rapid and non-destructive fashion, which offers important analytical advantages. In this investigation we have assessed the different LYC isomer contents by HPLC and the color of diverse tomato genotypes and tomato derived-products by SPR and DIA with four main purposes: 1) to compare the levels of LYC isomers in processed vs fresh tomato products, 2) to evaluate the validity of DIA and SPR to ascertain the color of these products, 3) to compare the ability of both instrumental methodologies to discriminate between the two different groups of samples, and 4) to compare the utility of both methodologies for estimating LYC levels. The results indicated that the parameters obtained by SPR and DIA were significantly correlated ( p

Digital imaging has become a powerful tool for the characterization and quality control of foodstuff. Because of the need to automate processes, faster tools are needed and Computer Vision is a good alternative to chemical analysis of many products in quality control. Appearance of grape seeds and grape berries change during the ripeness. These changes are closely related to the chemical composition, especially phenolics, which are very important compounds due to their implications on the intensity and stability of red wine colour. In this study, a complete characterization of grape seeds and grape berries by digital image analysis is described. The size of grapes and the veraison has been determined by image analysis and it has been also established an objective Browning Index of seeds. Morphological differences between varieties were studied by applying discriminant analysis models which allowed us to classify the grape seeds with high accuracy.

Gulupa (Passiflora edulis Sims. fo edulis) is a tropical fruit native to America. This study was undertaken to characterize the physicochemical properties of this fruit in three maturity stages. In all stages, the pH, °Brix, texture, and titratable acidity were determined. pH value and solid soluble content increased during ripening and titratable acidity decreased during this process; in contrast, texture values did not show significance variance. It was confirmed the presence of cyanidin-3-O-β-D-glucopyranoside as major anthocyanin. The changes on colour were followed by tristimulus colorimetry using image analysis, a very useful new approach for the measurement of non-homogeneous colours. By using PCA (Principal Component Analysis), clusters of data corresponding to each stage could be defined. Additionally, the volatile composition was followed by HS-SPME (Headspace-Solid Phase Microextraction) and GC/MS (Gas Chromatography/Mass Spectrometry) analyses. The results showed an increase in the amount of volatile during fruit ripening, with aliphatic esters as major constituents.

Solanum lycopersicum L. (tomato) is a very important fruit vegetable with high economic importance and nutritional impact on the consumers worldwide. Moreover, tomato fruits are an important source of nutraceutical compounds. This work describes the physiological diversity affecting the ripening process that yields variation in fruit pigmentation with regard to anthocyanins compounds for one non-anthocyanin-accumulating (Ailsa Craig) and two anthocyanin-accumulating tomato genotypes (anthocyanin fruit type, low pigment accumulation, and Sun Black, high pigment accumulation). Using tomato fruits obtained by traditional breeding the present study reported modified hormone equilibrium at different ripening stages. This phenomenon can be considered as a consequence of the different pattern in the anthocyanins accumulation in fruits. Moreover, the fruit genotype showing the highest pigment accumulation appear more firm at the commercial stage. Overall, these results showed the considerable potential of exploiting natural genetic diversity to obtain tomatoes with higher levels of anthocyanins, and different quality traits such as colour and firmness.

[EN] 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 flavanols. Chemometric analysis was performed to summarize the analytical results. None of the considered variables presented statistical differences among all groups. From one to five groups were found for each variable, while three was the most frequent value, consequently three putative stages might be considered the real number of different analytical stages since it is the number of statistically significant groups for the majority of the compounds. This classification could be considered as the first step to optimize the use of seeds in winemaking to minimize the gap between sugar and phenolic maturities, consequence of the global climate change, mainly observed in warm climate.

[EN] Oak chips-related phenolics are able to modify the composition of red wine and modulate the colour stability. In this study, the effect of two maceration techniques, traditional and oak chips-grape mix process, on the phenolic composition and colour of Syrah red wines from warm climate was studied. Two doses of oak chips (3 and 6 g/L) at two maceration times (5 and 10 days) during fermentation was considered. Changes on phenolic composition (HPLC–DAD–MS), copigmentation/polymerisation (spectrophotometry), and colour (Tristimulus and Differential Colorimetry) were assessed by multivariate statistical techniques. The addition of oak chips at shorter maceration times enhanced phenolic extraction, colour and its stabilisation in comparison to the traditional maceration. On contrast, increasing chip dose in extended maceration time resulted in wines with lighter and less stable colour. Results open the possibility of optimise alternative technological applications to traditional grape maceration for avoiding the common loss of colour of wines from warm climate.

The phenolic composition (by HPLC-DAD-MS) and color characteristics (by Imaging Tristimulus Colorimetry) of four strawberry cultivars that have shown good climate adaptation to subtropical area (Nikte, Zamorana, Jacona and Pakal) have been assessed. 24 monomeric phenolics were identified, including 15 anthocyanins, 5 phenolic acids, 1 flavanol and 4 flavonols. Nikte and Zamorana showed the highest phenolic potential mainly due to their higher content of anthocyanins, while Pakal was richer in phenolic acids. Regarding color, Nikte and Zamorana were the more similar cultivars having the lowest values of lightness and hue. On the contrary, the color of Pakal was quite different from all the rest, due to the specific distribution between pelargonidin and cyanidin. The inclusion of both phenolic and colorimetric information in the Linear Discriminant Analysis allowed reaching very good discriminations among cultivars.

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 (RMSEs) have been calculated to measure the differences between characteristic vector reconstructed spectra (CVRS) and hyperspectral imaging spectra (HIS). RMSE values obtained were 0.0049, 0.0018, 0.0012, and 0.0012 [log(1/R) units] for spectra allocated into the validation set, for 3, 6, 9, and 12 characteristic vectors, respectively. After that, calibration models have been developed and validated using the different groups of CVRS to predict skin total phenolic concentration, sugar concentration, titratable acidity, and pH by modified partial least-squares (MPLS) regression. The obtained results have been compared to those previously obtained from HIS. The models developed from the CVRS reconstructed from 12 characteristic vectors present similar values of coefficients of determination (RSQ) and standard errors of prediction (SEP) than the models developed from HIS. RSQ and SEP were 0.84 and 1.13 mg g−1 of skin grape (expressed as gallic acid equivalents), 0.93 and 2.26 °Brix, 0.97 and 3.87 g L−1 (expressed as tartaric acid equivalents), and 0.91 and 0.14 for skin total phenolic concentration, sugar concentration, titratable acidity, and pH, respectively, for the models developed from the CVRS reconstructed from 12 characteristic vectors

The combined effect of anthocyanin−flavanol−flavonol ternary interactions on the colorimetric and chemical stability of malvidin-3-glucoside has been studied. Model solutions with fixed malvidin-3-glucoside/(+)-catechin ratio (MC) and variable quercetin-3-β-D-glucoside concentration (MC+Q) and solutions with fixed malvidin-3-glucoside/quercetin-3-β-Dglucoside ratio (MQ) and variable (+)-catechin concentration (MQ+C) were tested at levels closer to those existing in wines. Color variations during storage were evaluated by differential colorimetry. Changes in the anthocyanin concentration were monitored by HPLC-DAD. CIELAB color-difference formulas were demonstrated to be of practical interest to assess the stronger and more stable interaction of quercetin-3-β-D-glucoside with MC binary mixture than (+)-catechin with MQ mixture. The results imply that MC+Q ternary solutions kept their intensity and bluish tonalities for a longer time in comparison to MQ+C solutions. The stability of malvidin-3-glucoside improves when the concentration of quercetin-3-β-D-glucoside increases in MC+Q mixtures, whereas the addition of (+)-catechin in MQ+C mixtures resulted in an opposite effect

Hyperspectral images of intact grapes were recorded at harvest time using a near infrared hyperspectral imaging system (900-1700 nm). Spectral data have been correlated with red grape skin extractable polyphenols (total phenolic, anthocyanins and flavanols) by modified partial least squares regression (MPLS) using a number of spectral pretreatments. The obtained results (coefficient of determination (RSQ) and standard error of prediction (SEP), respectively) for the developed models were: 0.82 and 0.92 mg g(-1) of grape skin for extractable total phenolic content, 0.79 and 0.63 mg g(-1) of grape skin for extractable anthocyanin content, 0.82 and 0.45 mg g(-1) of grape skin for extractable flavanol content. The obtained results present a good potential for a fast and reasonably inexpensive screening of the extractable polyphenolic compounds in intact grapes. Moreover, the heterogeneity of extractable polyphenols within the ripeness stage has been also evaluated using the proposed method.

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 number of spectral pretreatments and different mask development strategies were studied. Calibrations were performed by modified partial least-squares regression (MPLS) and present a good potential (RSQ of 0.86 and SEP values of 2.62 and 3.05 mg g(-1) of grape skin for nonacylated and total anthocyanins, respectively) for a fast and reasonably inexpensive screening of these compounds in intact grapes.

Chemical composition of seeds changes during grape ripening and this affects the sensory properties of wine. In order to control the features of wines, the condition of seeds is becoming an important factor for deciding the moment of harvesting by winemakers. Sensory analysis is not easy to carry out and chemical analysis needs lengthy procedures, reagents, and it is destructive and time-consuming. In the present work, near infrared hyperspectral imaging has been used to determine flavanols in seeds of red (cv. Tempranillo) and white (cv. Zalema) grapes (Vitis vinifera L.). As reference measurements, the flavanol content was estimated using the p-dimethylaminocinnamaldehyde (DMACA) method. Not only total flavanol content was evaluated but also the quantity of flavanols that would be extracted into the wine during winemaking. A like-wine model solution was used for this purpose. Calibrations were performed by partial least squares regression and they provide coefficients of determination R2=0.73 for total flavanol content and R2=0.85 for predicting flavanols extracted with model solution. Values up to R2=0.88 were reached when cultivars were considered individually.

The effect of adding American oak wood chips during fermentation on Tempranillo red wines elaborates in a warm climate has been studied. Our attention was focused on the tristimulus colorimetry, differential colorimetry and phenolic compounds related to wine colour. This technique was applied as an oenological alternative to the conventional winemaking for avoiding the common fall of colour of red wines elaborated in warm climates. The addition of oak wood chips promoted the colour enhancement and stabilisation, producing wines with a notably darker colour and with more bluish tonality. This fact was also related to the significantly higher content of some phenolic compounds. On the basis of the results, it could be affirmed that the addition of oak wood chips during fermentation induced visually perceptible colour changes (by the analysis of Δ E ab ∗ , %Δ2L, %Δ2C and %Δ2H), mainly in a quantitative way, and also a lower percentage of diminution of colour.

New colorimetric variables have been defined in the uniform CIELAB color space to assess the quantitative and qualitative color changes induced by copigmentation and their incidence on visual perception. The copigmentation process was assayed in model solutions between malvidin 3-glucoside and three phenolic compounds (catechin, epicatechin, and caffeic acid) as a function of the pH and the pigment/copigment molar ratio. Along the pH variation, the greatest magnitude of copigmentation was obtained at pH 3.0, being significantly higher with epicatechin and caffeic acid. At high acidic pH, the main contribution of copigmentation to the total color was qualitative, whereas between pH 2.0 and 4.0, the main colorimetric contribution was quantitative. The contribution of epicatechin and caffeic acid to the color changes was more marked for the quantitative characteristics. On contrast, particularly at higher pH values, the qualitative contribution was more important in catechin copigmented solutions. Increasing copigment concentration induced perceptible color changes at molar ratios higher than 1:2, consisting in a bluish and darkening effect of the anthocyanin solutions. Among the different CIELAB attributes, hue difference was the best correlated parameter with the increase of copigment concentration, proving the relevance of this physicochemical phenomenon on the qualitative changes of anthocyanin color.

[EN] The applications of computer vision technology for acquiring and analysing images have been extended to the quality evaluation in food industry. This technique involves great advantages for the objective, rapid, non-contact and automated quality inspection and control. The aim of this work was to evaluate the potential of the computer vision to determine the phenolic maturity stage of grape seeds. Up to 21 phenolic compounds were determined by HPLC–DAD-MS in order to obtain reference values to develop the model. The CIELAB parameters, area, aspect, roundness, length, width and heterogeneity of seeds were analysed using a DigiEye® system. The technique reported in this work can be a good and rapid tool for taking decisions at harvest time. Notwithstanding, a comprehensive study should be made in order to develop more robust models.