Study On Hawthorn Wine’s Antioxidant Capacity And Compound Clarifying Agent

Chinese hawthorn resource is rich, annual output of the hawthorn fruit amounts is more than one million tons. For its properties of rich nutrition and antioxidants, hawthorn has been applied to control hypertension, cure stomach ailments, and treat cardiovascular diseases. In recent years, intensive processing of hawthorn fruit has been encouraged by the Chinese government. As one of the most promising products, hawthorn wine production is growing. Thus, it was deemed important to investigate the effects of different yeast strains on hawthorn wines. To this end, we studied hawthorn fruits fermented by five active dry wine yeasts, evaluated the wines’characteristics and the antioxidant capacities. In addition, the clarifier of hawthorn wine was studied to improve clarification and stability of hawthorn wine.1. Hawthorn wines were fermented by five different wine yeast strains. The wines’ typical properties, colour density and colour tonality, total content of anthocyanin (TA), flavonoid (TF), and polyphenol (TP), were evaluated. Also, their antioxidant capacities, such as2,2-diphenyl-l-picrylhydrazyl (DPPH),2,2’-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide anion (O2.-scavenging activities, and ferric reducing antioxidant power (FRAP), were also determined. It was revealed that the yeast Y3had an excellent alcoholic fermentability; the wine fermented by yeast Y2had the highest colour tonality, while wine fermented by yeast Y1had the highest total content of polyphenol (TP) and anthocyanin (TA). Furthermore, the maximum DPPH and O2.-radical scavenging activity and FRAP value were also observed in wine fermented by yeast Y1. The strongest ABTS radical scavenging activity was found in wine fermented by yeast Y4, along with the maximum TF content. In addition, wine fermented by yeast Y5was found to have the highest colour density value.2. The correlation among the wines’typical properties, antioxidants, and antioxidant capacities were analysised, and it indicated that pH value was significantly correlated with colour density (-0.954**) and alcohol content (-0.905**) in hawthorn wines. And there was a strong positive correlation between TP content and antioxidant activity as determined by DPPH (0.915**) and FRAP (0.914**) assays, respectively.3. Three clarifiers (gelatin, PVPP, bentonite) were choosed to clarify the wines, their influences on wines was evaluated.The luminousness of the wines was improved slightly, the value changed from89.5to92.9、91.1and91.1respectively.The wines’color density value and turbidity value dropped slightly, and the TF content and TP content had reduced as well. Based on overall consederation, the optimum concentration of gelatin, PVPP, bentonite is60mg/L,1000mg/L and1200mg/L, respectively. According to the previous experiments, othogonal test was implemented. Comparative results indicate that compound clarifier was better than a single clarifier on the effect of clarification, the stability of wine was improved significantly. Othogonal test shows that the optimum formulation of three clarifiers are PVPP concentration of800mg/L, bentonite concentration of1400mg/L, gelatin concentration of80mg/L.