Abstract:The grape seed of Cabernet Sauvignon was studied, sodium hydroxide was used to degrade polymeric proanthocyanidins, and the degradation process was optimized through single factor experiment and response surface methodology. The mean degree of polymerization, proanthocyanidin content, changes in different components, and DPPH and ABTS free radical scavenging capabilities of the samples under different treatments and optimal degradation process conditions were analyzed. The results showed that the optimal degradation process conditions were 4.40% of sodium hydroxide concentration, 31 min of treatment time, and 59 ℃ of treatment temperature. Under these conditions, the average degree of polymerization of polymeric proanthocyanidins decreased from 5.71 to 2.37; the content of proanthocyanidins increased by 1.68 times; The peak areas of monomer, ECG and dimer increased by 14267.50, 28304.00, 52998.33 respectively, and the total peak area increased by 1.80 times. The free radical scavenging capacity of DPPH and ABTS increased by 2.41 times and 2.19 times, respectively. In summary, grape seed proanthocyanidins are degraded by sodium hydroxide to obtain oligomeric proanthocyanidins with strong antioxidant activity, which provides a theoretical basis for the development and utilization of polymeric proanthocyanidins in grape seeds, which is a byproduct of winemaking, and has certain practical application value and significance.
