Evaluation of Anthocyanin Profile and Color in Sweet Cherry Wine: Effect of Sinapic Acid and Grape Tannins during Aging

Cherries are rich in bioactive phenolic compounds and are often fermented into cherry wines. The degradation of anthocyanins during storage will cause color deterioration. The study aimed to utilize sinapic acid and grape tannins in cherry wine to maintain a high fraction in the colored forms of anthocyanins, in order to maximize the color intensity, the latter being associated with good product quality. The effects on the anthocyanin profile and on color parameters of copigments, utilizing spectral measurement combined with UPLC-MS quantitative analysis, have been evaluated in sweet cherry wines. The copigmentation effect of sinapic acid and grape tannin was accompanied by the bathochromic shift and the hyperchromic effect, which lead to an increase in color intensity (lower L*, higher a* and b*). During the aging process, sinapic and grape tannin increased the content of pyranoanthocyanins in cherry wine, especially the addition of sinapic acid makes the cherry wine generate 10-syringyl-pyranocyanidin-3-rutinoside. These results demonstrate that sinapic acid is suitable for adding before alcohol fermentation, while grape tannins can be added before aging.

Spectrophotometric Studies of Ternary Complexes of Erbium to Explore the Hyperchromic Effect with Various Ligands and their use in Microdetermination

A comprehensive spectrophotometric study is undertaken for ternary complexes of higher rare earth element Erbium with ethylene diamine tetra acetic acid ( EDTA), hydroxyl ethylene diamine triacetic acid (HEDTA), trans 1, 2, cyclohexane diamine tetra acetic acid (CYDTA) and ethylene glycol bis (2-amino ethylene) N,N1,N11,N1 1 1 tetra acetic acid (EGTA) as primary ligand and the binary ligands used are Maltol, Tiron, Kojic acid and α-Picolinic acid. The ternary complexes shows hyperchromic effect as compare to primary complexes which is exploited to determine the stoichiometry of ternary complexes and it is found to be 1:1:1. The conditional stability constants (Ks1) are corrected using k H values of ligands. The order of stability with the series of ligands in different systems is deduced as EDTA and HEDTA: α Picolinic acid >Tiron> Kojic acid > Maltol and CYDTA and EGTA: α Picolinic acid > Kojic acid > Tiron > Maltol. The % increase in molar coefficients of mixed ligand complexes of Erbium is significant which can facilitates the analytical measurements for its micro determination.

Thermodynamic investigations of the copigmentation process between strawberry anthocyanins and rose petal polyphenols (Rosa damascena Mill.) at different temperatures

In this study the model systems between strawberry anthocyanins as pigment and rose polyphenols as copigment was investigated. The solutions were prepared from 1:2 to 1:10 pigment:copigment. The addition of increasing concentrations of rose petal polyphenols resulted in a gradual increase of hyperchromic effect. The absorption was determined at heating system from 20 to 50 oC and following cooling the same system from 50 to 20 oC. All calculated thermodynamic parameters were negative. The copigmentation reaction was determined as spontaneous, exothermic and thermally reversible.

Influence of Saccharomyces and non-Saccharomyces Yeasts in the Formation of Pyranoanthocyanins and Polymeric Pigments during Red Wine Making

Yeast are able to modulate many sensory parameters of wines during red must fermentation. The effect on color and on the formation of derived pigments during fermentation has been studied thoroughly since the 90s. Yeast can increase grape anthocyanin’s color by acidification by hyperchromic effect (increase of flavylium molecules). Recent studies with non-Saccharomyces species, as Lachancea thermotolerans, described the intense effect of some strains on anthocyanin’s color, and subsequent, stability, by strongly reducing wine’s pH during fermentation. Moreover, selected yeast strains of Saccharomyces have been shown to release metabolites such as pyruvic acid or acetaldehyde that promote the formation of vitisin A and B pyranoanthocyanins during must fermentation. Schizosaccharomyces pombe, because of its specific metabolism, can produce higher concentrations of pyruvate, which enhances the formation of vitisin A-type derivatives. The hydroxycinnamate decarboxylase activity that some Saccharomyces strains express during fermentation also promotes the formation of vinylphenolic derivatives. Some non-Saccharomyces species, such as S. pombe or P. guilliermondii can also improve the production of these derivatives compared to selected strains of Saccharomyces cerevisiae. Lastly, some yeasts are also able to modulate the formations of polymeric pigments between grape anthocyanins and flavonoids, such as catechins and procyanidins.

Catalytic properties of plate-like cadmium oxide nanoparticles in removal of sulfathiazole with anticancer activity

The study of the interaction of drugs with DNA is very exciting and significant not only for understanding the mechanism of the interaction but also for the design of new drugs. Here, we report the results of Fourier transform infrared (FT-IR) and ultraviolet (UV)-visible spectroscopy studies to determine the external binding modes of sulfathiazole (STZ), and the binding constant and stability of the STZ-DNA complex in aqueous solution. The results of absorption spectra showed that the interaction of STZ-DNA is weak because there is only a hyperchromic effect. A hyperchromic effect reflects the corresponding changes of DNA in its conformation and structure after the drug-DNA interaction has occurred. Spectroscopic evidence revealed that STZ binds DNA with an overall binding constant of K (STZ-DNA)=0.42×103 m−1. FT-IR spectroscopy showed that the complexation of STZ with DNA occurred via A-T and PO2 groups. Nano cadmium hydroxide has been synthesized using hexamine as the template at room temperature. Then, this nano cadmium hydroxide recrystallizes into nano cadmium oxide (CdO) at 400°C for 2 h. The product was characterized by using X-ray diffraction and scanning electron microscopy. The presence of drugs in aquatic media has emerged in the last decade as a new environmental risk. The other aim of this study was to investigate the degradation of the STZ antibiotic by nanosized CdO under ultraviolet irradiation. Various experimental parameters, such as initial CdO concentration, initial pH, and reaction times, were investigated. According to the results, this method has a good performance in the removal of STZ.