《食品工业科技》F5000论文展播：五种寒地果树果实的多酚含量、抗氧化活性及抗α-淀粉酶活性分析（2022年）

Objectives:Due to the rising incidence rate and mortality of chronic diseases, and the potential side effects of clinical oral drugs, the use of bioactive substances in plants as natural products to prevent and assist in the treatment of chronic diseases has attracted widespread attention. The fruits grown in cold region are rich in sugars and acids, mineral elements, amino acids, and various phenolic substances, which have a good effect in preventing chronic diseases and maintaining human health. The kiwiberry, black chokeberry, sour cherry, white currant and cranberry are excellent cold region characteristic fruit trees, and further research is needed on their secondary metabolites and physiological activities. Therefore, this article focuses on the total phenolic and anthocyanin contents, antioxidant and antioxidant properties of the five dryland characteristic fruit trees mentioned above α-measurement, comparison, and evaluation of amylase activity.

Methods:Firstly, freeze dry and grind the collected five types of fruits, including kiwiberry, black chokeberry, sour cherry, white currant and cranberry, and used 80% methanol as the extraction solvent to obtain polyphenol extracts from the five types of fruits. Secondly, the polyphenol content and total anthocyanin content of the five fruit polyphenol extracts were measured using the Folin phenol method and pH differential method, respectively. The antioxidant activity was evaluated using four methods: DPPH• method, ABTS⁺• method, ferric ion reducing antioxidant power (FRAP), and oxygen radical absorption capacity (ORAC). The effects of five polyphenol extracts on α-amylase inhibitory activity were also studied. Finally, the correlationship of total phenolic content (TPC), total anthocyanin content (TAC), antioxidant activity and α-amylase inhibitory activity were analyzed. 

Results:There were significant differences in the total phenolic and total anthocyanin contents among the five cold region fruits (P<0.05). The total phenol content ranges from 13.21 to 66.43mg GAE/100 g, with the highest content in black chokeberry and followed by white currant. The total anthocyanin content was 0.15~46.45 mg C3G/100 g, with the highest content in black chokeberry, followed by sour cherry. The antioxidant capacity of the five fruits also varies. The scavenging ability of fruit polyphenols on DPPH• and ABTS⁺•, from strong to weak, was as follows: white currant>black chokeberry>sour cherry>cranberry>kiwiberry. White currant fruit polyphenols had the strongest ability to inhibit DPPH• and ABTS⁺•, with 414.46, respectively μmol TEg^-1 and 2662.74 μmol TEg^-1, significantly higher than other fruits (P<0.05). The order of fruit polyphenols' ability to reduce iron ions (FRAP) from strong to weak was as follows: black chokeberry>kiwiberry>white currant>sour cherry>cranberry. The antioxidant capacity measured by ORAC method, from strong to weak, was as follows: kiwiberry>white currant>sour cherry>cranberry>black chokeberry. Determination of white currant using high-throughput starch turbidity method on α-amylase inhibitory activity was the strongest, with an IC₅₀ of 0.122 mg/mL, higher than acarbose (0.16 mg/mL), and an AE value of 2034.18 mmol AE/g, higher than acarbose (1550 mmoL AE/g), which was 42~127 times higher than other fruits. Correlation analysis found that there was a highly significant positive correlation (P<0.01) between the total phenolic and anthocyanin contents, as well as antioxidant activity, of the five cold region fruits, and no significant correlation with α-amylase inhibitory activity. 

Conclusion: This study investigated the polyphenol content, antioxidant activity, antioxidant activity and α-amylase inhibitory activity of five cold region fruits showed that the total phenolic content and total anthocyanin content of black chokeberry were significantly higher than those of white currant, sour cherry, kiwiberry and cranberry (P<0.05), while the total phenolic content of white currant was only second to black chokeberry. black chokeberry, white currant, and kiwiberry exhibited high antioxidant activity. Resistance of white currant on α-amylase inhibitory activity was significantly stronger than the other four cold region fruits (P<0.05). In addition, correlation analysis showed that there was a highly significant correlation (P<0.01) between the TPC, TAC, and antioxidant activity of the five types of fruits in cold regions, while no significant correlation with α-amylase inhibitory activity. In summary, the black chokeberry and white currant are rich in polyphenols, which would be good raw materials for obtaining natural polyphenols, and have good antioxidant effects. Among them, white currant have outstanding ability in α-amylase inhibitory, and it has better hypoglycemic ability than acarbose, but its hypoglycemic mechanism still needs to be explored.