Effects of heat, ultrasound, and microwave processing on the stability and antioxidant activity of delphinidin and petunidin

Abstract

The effects of conventional heating, ultrasonic, and microwave treatments on the stability and antioxidant activities of anthocyanidin standards (delphinidin and petunidin) were studied. The antioxidant activities of delphinidin and petunidin significantly decreased during the treatments, which suggested that the antioxidant activities of the degradation products were lower than that of anthocyanidin. In addition, the degradation of delphinidin and petunidin followed first‐order reaction kinetics. The kinetic parameters indicated that delphinidin was more stable than petunidin. The microwave treatment led to the fastest degradation, followed by the conventional heating and ultrasonic treatments. Moreover, three types of degradation products of delphinidin were found by HPLC‐Q‐TOF‐MS after all three treatments, and they were phloroglucinaldehyde, delphinidin chalcone, and 3,4,5‐trihydroxybenzoic acid. Petunidin was broken into phloroglucinaldehyde, petunidin chalcone, and 3‐methoxy‐4,5‐ dihydroxybenzoic acid. Practical applications Anthocyanins with great antioxidant activity are widely distributed in plants. The stability of the anthocyanin affects its antioxidant activity and bioavailability. When anthocyanins are degraded, their antioxidant activities change accordingly. Therefore, it is crucial to study the structure, stability, and antioxidant activity of anthocyanins. This paper explores the structures and pyrolysis pathways of delphinidin and petunidin and provides basic data for the utilization and preservation of anthocyanins during food processing and production.

Influence of the Anthocyanin and Cofactor Structure on the Formation Efficiency of Naturally Derived Pyranoanthocyanins

“…Furthermore, after incubation at 45 • C for 24 h, there was little to no pigment remaining in these samples; this negates the possibility of PACN formation with increased incubation times. Delphinidin's and petunidin's propensity to degrade during prolonged heating [42,43] may explain the absence or reduced formation of PACNs in these samples. The significantly higher yields of malvidin-and cyanidin-derived PACNs may explain why most reports have especially identified these derivatives [11,14,16,19,25,44,45].…”

A Review of the Current Knowledge of Thermal Stability of Anthocyanins and Approaches to Their Stabilization to Heat

“…It has been demonstrated that the presence of a glucose residue at position 5 (ring A) has a minimal influence on the kinetics of the proton transfer equilibrium, but significantly increases the hydration rate, slowing down the reverse reaction [13]. Similarly, other authors suggested that the thermal degradation of anthocyanins, in particular at pH 3.5, follows the pathway of intermediate chalcone and final derivatives of aldehyde and benzoic acid, structurally differentiated based on the corresponding anthocyanidin [15][16][17][18][19], as illustrated in Figure 2 for the most abundantly distributed anthocyanidins in fruits and vegetables (cyanidin, pelargonidin, delphinidin, malvidin and petunidin). Combined hydrolytic and autooxidative reactions are probably involved [20].…”

Anthocyanins Recovered from Agri-Food By-Products Using Innovative Processes: Trends, Challenges, and Perspectives for Their Application in Food Systems

“…Similar behavior was reported by Liazid et al [ 144 ] in grape skin anthocyanins, in which MW treatment remarkably enhanced the acylated glucoside anthocyanin recovery regarding monoglucoside anthocyanins compared to the solid-liquid maceration classical method. Wang et al [ 145 ] observed that delphinidin was more stable than petunidin under MW treatment. Meanwhile, Sivamaruthi et al [ 146 ] verified that petunidin was more stable than cyanidin after MW exposure.…”