Effect of ascorbic acid on tyrosinase and its anti‐browning activity in fresh‐cut Fuji apple

Abstract

Tyrosinase (polyphenol oxidase) is the key enzyme of enzymatic browning in fruits and vegetables. In this research, the impact of ascorbic acid on tyrosinase and its anti‐browning effect on fresh‐cut Fuji apple were investigated. Ascorbic acid had a dual effect on tyrosinase with a half inhibitory concentration (IC50) of 13.40 ± 0.05 µM. Fluorescence assay demonstrated that ascorbic acid interacted with tyrosinase in a dynamic contaction caused by Förster’s resonance energy transfer (FRET) and induced a conformational change of the enzyme. Thermodynamic analysis, copper interaction, and molecular docking further confirmed that ascorbic acid could chelate the copper ions located in active center and interact with amino acid residues of tyrosinase via hydrophobic interaction. In addition, ascorbic acid prevented the browning of fresh‐cut apples by increasing APX activity and inhibiting PPO and POD activities which reduce the oxidation of total phenolics and flavonoids. Practical applications The present study demonstrated that ascorbic acid had a strong inhibitory activity against tyrosinase (IC50 = 13.40 ± 0.05 µM) and anti‐browning activity against fresh‐cut Fuji apple. It could delay the browning degree of apple juice, increase APX activity, inhibit PPO and POD activities, and reduce the oxidation of total phenolics and flavonoids. These findings provided a basis for the feasible application of ascorbic acid on the preservation of fruits.

Ultrasonic treatment decreases Lyophyllum decastes fruiting body browning and affects energy metabolism

“…Postharvest fruit and vegetables have strong physiological metabolism and high oxidase activity leading to postharvest horticultural product senescence by accelerating the enzymatic browning rate [30] . Browning is an important aspect affecting the shelf life of fruit and vegetables [31] . Reduced oxidase activity improves the storage quality of postharvest horticultural products [32] .…”

Inhibition of albendazole and 2‐(2‐aminophenyl)‐1H‐benzimidazole against tyrosinase: mechanism, structure–activity relationship, and anti‐browning effect

“…Furthermore, the r values of albendazole and 2‐2‐A‐1HB were 4.43 and 4.98 nm (Table 3), respectively. Obviously, the r values (4.43 and 4.98 nm) were less than 8 nm and the range was 0.5 R 0 < r < 1.5 R 0 , which indicated that the fluorescence quenching of tyrosinase by these two benzimidazole derivatives was a non‐radiation energy transfer process 37 …”

“…PPO and POD were extracted according to a previous report 37 . Three‐gram fresh‐cut apple slices were ground under an ice bath with 5.4 mL Na 2 HPO 4 –NaH 2 PO 4 buffer and 0.6 mL PVP.…”

Biosensors Based on Phenol Oxidases (Laccase, Tyrosinase, and Their Mixture) for Estimating the Total Phenolic Index in Food-Related Samples

“…Compared to laccase, tyrosinase has catalytic specificity for phenolic compounds; however, potentiometric [ 108 ] and amperometric [ 110 ] tyrosinase biosensors could still suffer from interference from ascorbic acid. The interfering effect of ascorbic acid in tyrosinase biosensors may be due to its ability to reduce the induction period of the hydroxylation reaction [ 133 ] or to inhibit tyrosinase by copper chelation [ 134 ]. The studies of interference in laccase-tyrosinase biosensors are limited, which offers new research opportunities.…”