Open Access
Stability of phenolic compounds in grape stem extracts
(MDPI, 2020) Esparza Catalán, Irene; Cimminelli, María José; Moler Cuiral, José Antonio; Jiménez Moreno, Nerea; Ancín Azpilicueta, Carmen; Zientziak; Estatistika, Informatika eta Matematika; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Estadística, Informática y Matemáticas; Gobierno de Navarra / Nafarroako Gobernua, VARASVI PI022 and PI039
Grape stem is rich in phenolic compounds, especially stilbenes. These antioxidants can be degraded during the storage of grape stem extracts for long periods of time. The aim of this work was to analyze the stability of Mazuelo stem extracts during storage at 25 and 40◦C, in two different light conditions (amber and transparent vials). The stability of the antioxidants was studied after 2, 4 and 6 months of conservation. Gallic acid and the quercetin derivative concentration were stable throughout the storage period. In contrast, catechin disappeared from all the extracts in just two months of storage. Anthocyanins were significantly affected by temperature, and light enhanced their degradation when the extracts were kept at 40◦C. Resveratrol and viniferin showed a similar behavior. Their concentration decreased from the beginning of storage, and in both cases, they were significantly affected by both temperature and light.
Open Access
Development of an irradiation equipment to accelerate the degradation of rosé wine in antique green and flint bottles
(Elsevier, 2023) Moriones, Jennifer; Jiménez Moreno, Nerea; Ancín Azpilicueta, Carmen; Fernández de Ara, Jonathan; Navarcorena, Beatriz; Almandoz Sánchez, Eluxka; Esparza Catalán, Irene; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2
Flint bottles make ros´e wines more attractive to the customers and, also, allow them to detect oxidation problems in the color of these wines. Nonetheless, transparent bottles do not protect wines from light. In this work, a device capable of accelerating the degradation of ros´e wines using W lamps radiation for short times of exposure has been developed. This equipment has been used to accelerate the color photodegradation of ros´e wines, allowing, thus, to identify which parameters can be used as markers of such degradation. The irradiation treatment applied to ros´e wines bottled in different types of glass (Flint and Antique Green glass) influenced all the samples. However, the wines treated in Flint bottles displayed more important color variations, especially in color intensity (CI) and hue, than the wines treated in Antique Green bottles. These changes entailed a quality loss of ros´e wines that can be appreciated with a naked eye. The yellow component of ros´e wines treated in transparent bottles increased the detriment of the red and blue ones. Therefore, color parameters such as CI and a*, together with the total anthocyanin content, seem to be good markers of the loss of quality of ros´e wines due to the light effects. The next step will be to find a physical, chemical or physical-chemical protection strategy that, when applied to transparent glass, allow to achieve the light-filtering properties of green glass bottles.
Open Access
Reducing SO₂ doses in red wines by using grape stem extracts as antioxidants
(MDPI, 2020) Esparza Catalán, Irene; Martínez Inda, Blanca; Cimminelli, María José; Moler Cuiral, José Antonio; Jiménez Moreno, Nerea; Ancín Azpilicueta, Carmen; Zientziak; Estatistika, Informatika eta Matematika; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Estadística, Informática y Matemáticas; Gobierno de Navarra / Nafarroako Gobernua, VARASVI PI022 and PI038
SO₂ is a very important wine preservative. However, there are several drawbacks associated with the use of SO₂ in wine. The aim of this work is to evaluate the effect of the partial substitution of SO₂ in the Tempranillo wine by a Mazuelo grape stem extract and by a commercial vine wood extract (Vinetan®). The results were compared with a control sample (with no addition of any extract). After 12 months of storage in a bottle, total anthocyanin content, together with total polyphenol and flavonoid content were slightly higher for control wines than for those treated with extracts. These differences were of little relevance, as no differences in antioxidant activity were found between any of the wines at the end of the study. The sensory analysis revealed that the use of both extracts as partial substitutes of SO₂ could lead to wines with good organoleptic properties, similar or even better to the control ones.
Open Access
Impact of extraction conditions on the phenolic composition and antioxidant capacity of grape stem extracts
(MDPI, 2019) Jiménez Moreno, Nerea; Volpe Sainz, Francesca; Moler Cuiral, José Antonio; Esparza Catalán, Irene; Ancín Azpilicueta, Carmen; Zientziak; Estatistika, Informatika eta Matematika; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Estadística, Informática y Matemáticas; Gobierno de Navarra / Nafarroako Gobernua
The use of grape stems for the extraction of bioactive compounds to be used in the pharmaceutical, food, and cosmetic industries is a promising objective. The aim of this work is to determine the influence of the different extraction conditions (temperature, ethanol concentration, and ratio of sample/solvent) on phenolic composition and antioxidant capacity of Mazuelo stem extracts. In general, the ethanol concentration of the extraction solvent was the factor that had the greatest influence on the extraction of different bioactive compounds. The greatest content of total phenolic compounds and the highest antioxidant activity of the extracts were obtained with 50% ethanol and at 40 °C. The most abundant compound found in the different extracts obtained from Mazuelo grape stem was (+)-catechin, but appreciable concentrations of gallic acid, a quercetin derivative, and stilbenes (trans-resveratrol and trans-ε-viniferin) were also extracted. Quercetin and malvidin-3-glucoside showed the highest correlation with the antioxidant capacity of the extracts, while stilbenes did not present such relation. The maximum concentration of gallic acid was extracted with water but the extraction of most of the compounds was maximum on using 50% ethanol. Consequently, the selection of the extraction method to be used will depend on the particular compound to be extracted in greatest quantity.
Open Access
Evaluation of grape stems and grape stem extracts for sulfur dioxide replacement during grape wine production
(Elsevier, 2023) Pires Nogueira, Danielle; Jiménez Moreno, Nerea; Esparza Catalán, Irene; Moler Cuiral, José Antonio; Ferreira-Santos, Pedro; Sagüés Sarasa, Ana; Teixeira, José António; Ancín Azpilicueta, Carmen; Ciencias; Zientziak; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa; Institute for Advanced Materials and Mathematics - INAMAT2
Sulfur dioxide (SO2), the main preservative in wine, may affect the sensory properties of the wines, as well as cause allergic reactions and headaches in sensitive people. The aim of this work was to evaluate the replacement of SO2 in Tempranillo wines with Mazuelo grape stem products. Five Tempranillo red wines were elaborated: positive control (60 mg/L SO2); negative control with no preservatives; Mazuelo extract (200 mg/L); Mazuelo extract combined with SO2 (100 mg/L + 20 mg/L); and Mazuelo stem (400 mg/L). The oenological parameters, antioxidant capacity, total phenolic (TP), total flavonoids (TF) and total anthocyanins (TA) contents were determined. Additionally, individual phenols were analyzed by HPLC-DAD-FLD. The spectrophotometric analyses showed that the wines had similar antioxidant capacities and concentrations of TP and TF. However, TA was more affected by the lack of SO2 as anthocyanins presented higher concentrations in positive control samples. The concentrations of individual phenols followed a similar path in all samples. Wines containing sulfites were more similar than the other treatments. However, these similarities were not reflected on the sensory analysis performed, as triangle test did not show differences between the wine with extract addition and the positive control wine. Therefore, Mazuelo stem extract could be a possible strategy for SO2 replacement. Nevertheless, further studies are necessary to confirm the potential of grape stem extracts as wine preservative.
Open Access
Phenolic composition of artichoke waste and its antioxidant capacity on differentiated Caco-2 cells
(MDPI, 2019) Jiménez Moreno, Nerea; Cimminelli, María José; Volpe Sainz, Francesca; Ansó Blanco, Raúl; Esparza Catalán, Irene; Mármol, Inés; Rodríguez Yoldi, María Jesús; Ancín Azpilicueta, Carmen; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
Artichoke waste represents a huge amount of discarded material. This study presents the by‐products (bracts, exterior leaves, and stalks) of the 'Blanca de Tudela' artichoke variety as a potential source of phenolic compounds with promising antioxidant properties. Artichoke residues were subjected to different extraction processes, and the antioxidant capacity and phenolic composition of the extracts were analyzed by spectrophotometric methods and high performance liquid chromatography (HPLC) analyses, respectively. The most abundant polyphenols in artichoke waste were chlorogenic acid, luteolin‐7‐O‐rutinoside, and luteolin‐7‐O‐glucoside. Minor quantities of cynarin, luteolin, apigenin‐7‐O‐glucoside, apigenin‐7‐O‐rutinoside, and naringenin‐7‐O-glucoside were also found. The antioxidant activity of the obtained extracts determined by ABTS [2, 2’‐azinobis (3‐ethylbenzothiazoline‐6‐sulphonic acid)], DPPH (2,2‐diphenyl‐1‐pycrilhydracyl), and FRAP (Ferric Ion Reducing Antioxidant Power) was highly correlated with the total concentration of phenolic compounds. Chlorogenic acid, luteolin‐7‐O‐glucoside, and luteolin‐7‐O‐rutinoside, the most abundant compounds in 60% methanol extracts, are the components most responsible for the antioxidant activity of the artichoke waste extracts. The extract with the best antioxidant capacity was selected to assay its antioxidant potential on a model intestinal barrier. This action of the hydroxycinnamic acids on intestinal cells (Caco-2) was confirmed. In summary, artichoke waste may be considered a very interesting ingredient for food functionalization and for therapeutic purposes.