Research progress of wine aroma components: A critical review.

As an important sensory indicator, aroma affects the quality of wine and consumer preference. In this review, the following aspects are comprehensively analyzed: (1) Varietal aroma, fermentation aroma and aging aroma formation mechanism include metabolic pathways etc. (2) The main factors affecting the aroma formation include environment, raw and auxiliary materials and brewing process. (3) In the process of winemaking, environmental factors can be controlled by regulating deficit irrigation, leaf removal and reflective mulch; the quality of raw and auxiliary materials can also be controlled through the varieties breeding of grape and yeast; flash evaporation, ultrasonic aging and other advanced brewing technologies can be used to synergistically control aroma formation. In the future, the wine brewing process can be controlled from the following aspects to ensure the precise regulation of aroma. This research will provide a theoretical basis for the improvement of wine production technology and quality.

A review of the interaction between anthocyanins and proteins.

Anthocyanins have good physiological functions, but they are unstable. The interaction between anthocyanins and proteins can improve the stability, nutritional and functional properties of the complex. This paper reviews the structural changes of complex of anthocyanins interacting with proteins from different sources. By circular dichroism (CD) spectroscopy, it was found that the contents of α-helix (from 15.90%-42.40% to 17.60%-52.80%) or ß-sheet (from 29.00%-50.00% to 29.40%-57.00%) of the anthocyanins-proteins complex increased. Fourier transform infrared spectroscopy showed that the regions of amide I (from 1627.87-1641.41 cm-1 to 1643.34-1651.02 cm-1) and amide II (from 1537.00-1540.25 cm-1 to 1539.00-1543.75 cm-1) of anthocyanins-proteins complex were shifted. Fluorescence spectroscopy showed that the fluorescence intensity of the complex decreased from 150-5100 to 40-3900 a.u. The thermodynamic analysis showed that there were hydrophobic interactions, electrostatic and hydrogen bonding interactions between anthocyanins and proteins. The kinetic analysis showed that the half-life and activation energy of the complex increased. The stability, antioxidant, digestion, absorption, and emulsification of the complex were improved. This provides a reference for the study and application of anthocyanins and proteins interactions.

Isolation and structural identification of the main anthocyanin monomer in Vitis amurensis Rupr.

Many types of anthocyanins are present in Vitis amurensis Rupr of 'Beibinghong', which is grown in North-east China and has high antioxidant activity. However, the anthocyanin with the highest content in V. amurensis Rupr has not yet been identified. In this study, pulsed electric field extraction and semi-preparative liquid phase separation were used to isolate the anthocyanin monomer from 'Beibinghong'. UV-vis spectroscopy, FTIR spectroscopy, mass spectra and nuclear magnetic resonance were used to identify the anthocyanin monomer. The antioxidant activities of the anthocyanin monomer were also analysed. Malvidin-3,5-O-diglucoside was identified as the main anthocyanin in V. amurensis Rupr, which could be used as a raw material for its extraction. Furthermore, malvidin-3,5-O-diglucoside can be potentially used as a functional food, and a novel therapeutic and preventive agent for oxidative stress-related diseases. This study provides technical information for the future purification and structural identification of anthocyanins.