Abstract:
To explore novel antioxidants, this study prepared Maillard reaction products(WBP-MRPs)and non-Maillard reaction control products(WBP-NMRPs)from
Wodyetia bifurcata pulp. The differences between the two were clarified through
in vitro antioxidant activity analysis, and high-activity WBP-MRPs were subsequently prepared. The Box-Behnken response surface methodology was employed to optimize the preparation process of WBP-MRPs using DPPH radical scavenging rate as the response indicator. Meanwhile, the application potential of WBP-MRPs was investigated from four aspect:
in vitro simulated gastrointestinal digestion stability, the influence of metal ion, and tolerance to temperature and pH. The results showed that the DPPH radical scavenging capacity of WBP-MRPs was significantly superior to that of WBP-NMRPs(
P<0.01). When the sample concentration was 0.8 mg·mL
−1, the free radical scavenging rate of WBP-MRPs was approximately 3.78 times that of WBP-NMRPs, with a significant difference between the two. The optimal preparation process for WBP-MRPs obtained through response surface optimization was as follows: reaction temperature of 85°C, reaction time of 73 min, and reaction system pH of 8. Under these conditions, the DPPH radical scavenging rate of WBP-MRPs reached 80.60%. Further quantitative analysis of antioxidant activity characteristics indicated half-maximal inhibitory concentrations(IC
50)of WBP-MRPs against DPPH radicals, ABTS radicals and hydroxyl radicals were 14.10±2.39 μg·mL
−1, 9.58±1.01 mg·mL
−1, and 2.03±1.53 mg·mL
−1, respectively. Stability analysis demonstrated that after
in vitro simulated gastrointestinal digestion, the antioxidant activity retention rate of WBP-MRPs was 61.24%. Among the tested metal ions, Ca
2+, Cu
2+, Zn
2+, and Fe
2+ could extremely significantly reduce on the antioxidant activity of WBP-MRPs(
P<0.01), while K
+ had no significant effect on its antioxidant activity(
P>0.05). In addition, when the temperature was ≤ 80°C, the antioxidant activity of WBP-MRPs did not change significantly(
P>0.05); when the pH was ≤ 8, the antioxidant activity of WBP-MRPs also did not change significantly(
P > 0.05). This indicated that the temperature sensitivity threshold of WBP-MRPs was 80°C, and the pH sensitivity threshold was 8. In conclusion, WBP-MRPs prepared from
W.
bifurcata pulp exhibit favorable antioxidant activity and gastrointestinal digestion stability, but demonstrate weak tolerance to high temperature and alkaline environment(pH>8). This research results can provide basic data for the development of antioxidant active substances based on the Maillard reaction, and offer new ideas and theoretical support for the high-value processing and utilization of
W.
bifurcata pulp.