Synergistic inhibitory effects of EGCG and chitosan or sodium alginate on 5-hydroxymethylfurfural formation in biscuits

Hydroxymethylfurfural (5-HMF) is a heat-induced hazard that common in baked goods. Although bioactive compounds such as catechins and polysaccharides could inhibit 5-HMF, their inhibition efficiency was limited when used alone. Therefore, this study aimed to explore the synergistic inhibitory impact of catechins and polysaccharides on 5-HMF in biscuits. Epigallocatechin gallate (EGCG), chitosan, and sodium alginate were screened out due to their high maximum inhibition rates (55.90, 67.20 and 66.62%, respectively), and their synergistic inhibitory effects on 5-HMF were investigated by isobologram analysis. The interaction index (γ) varies inversely with the synergism. When γ < 1 or >1, it represented synergism or antagonism, respectively. The results showed the EGCG/chitosan ratios of 1:1 (γ = 0.221) had better synergism than that of 1:2 (γ = 0.671) and 1:3 (γ = 0.523). Moreover, EGCG and sodium alginate only showed a synergistic effect at ratio of 1:1 (γ = 0.358), while an antagonistic effect was observed at ratios of 1:2 and 1:3 (γ = 1.12 and 1.25, respectively). The optimal inhibitory effect (54.57%) was achieved when EGCG-sodium alginate (1:1) at 0.2 g/kg. Compared with those used alone, the co-addition of EGCG and chitosan could decrease the dosage of EGCG to 1/5 and that of chitosan to 1/7, indicating a significant improvement of inhibit efficiency. Finally, Inhibitors’ concentration correlated negatively with 5-HMF content and browning index, suggesting they might inhibit 5-HMF by hindering Maillard or caramelization reactions. This study provided an efficient and cost-effective solution for 5-HMF control in baking products.