Copigmentation effect of three phenolic acids on color and thermal stability of Chinese bayberry anthocyanins

Abstract

The copigmentation effects of three phenolic acids (ferulic acid, sinapic acid, and syringic acid) on the color and thermal stability of Chinese bayberry anthocyanins were investigated. The three copigments of ferulic acid, sinapic acid, and syringic acid were found to have significant effects on the color enhancement of bayberry anthocyanins ( p < .05). The maximum absorption wavelength of the anthocyanin aqueous solution exhibited a bathochromic shift, L * decreased, and a * increased with the increase in the molar ratio of copigments. The thermal stability of bayberry anthocyanins was significantly improved after copigmentation. No new anthocyanin derivatives appeared after copigmentation. The thermodynamic parameters (Δ G , Δ H , Δ S ) of the three processes were all negative, indicating the three copigmentations were generally spontaneous and exothermic. The equilibrium constant ( K ) of the sinapic acid group was the greatest among the three phenolic acids, indicating that sinapic acid was more effective in stabilizing the anthocyanins.

Evaluation of Anthocyanin Profile and Color in Sweet Cherry Wine: Effect of Sinapic Acid and Grape Tannins during Aging

“…The lower L* value involves darkness, which may be due to the hyperpigmentation effect caused by copigmentation [24]. Throughout the aging stage, the BFSA group always maintained significantly lower L* values and higher a* values, which were consistent with higher anthocyanin content [36] and presented as a more red-orange color. In the aging stage, L* of the control group showed an upward trend, while a* and b* showed a downward trend (Figure 4).…”

“…The total anthocyanin content of cherry juice before alcohol fermentation was 31.3 mg/L, while after alcohol fermentation, it decreased to 5.1 mg/L. Zhu et al [ 36 ] investigated that the strongest immediate copigmentation effect at the 1:30 molar ratio occurred between the anthocyanins and sinapic acid. The excellent copigmentation effect of the BFSA group may be contributed by the molar ratio close to 1:30 when 300 mg/L sinapic acid was added before fermentation.…”

Co-pigmentation of strawberry anthocyanins with phenolic compounds from rooibos

“…Similarly, Müller-Maatsch et al (2016) previously observed increased hyper- and bathochromic shifts caused by adding an excess of mango peel extract, up to 1:100 pigment-to-co-pigment molar ratio, to red radish and strawberry model solutions rich in acylated or non-acylated pelargonidin derivatives, respectively. In another instance, the color stability of Chinese bayberry anthocyanins was enhanced by adding ferulic, sinapic, and syringic acid co-pigments, providing the most prominent effects at their highest pigment-to-co-pigment molar ratio, that is 1:30 ( Zhu et al, 2020 ). Chlorogenic acid addition to acylated and non-acylated cyanidin-3-glucosides isolated from black carrot similarly showed concentration-dependent hyper- and bathochromic shifts ( Gras, Bause, Leptihn, Carle, & Schweiggert, 2018 ).…”

“…The thermal effect was substantial at a low molar ratio (1:10 PE:OE) of green rooibos extract added model solutions, inducing significantly lower hyperchromic shifts (1.9 ± 1.2%) compared to that of non-heated model solutions (8.1%, Table S1 ). Hydroxycinnamic acid addition to Chinese bayberry anthocyanins ( Zhu et al, 2020 ) and hydroxybenzoic acid and flavonoid additions to blackberry wine residue anthocyanins similarly enhanced their heat stability up to 90 °C ( Fan et al, 2019 ). Enhanced thermostabilities of co-pigmented anthocyanins are attributed to the increased activation energies (E a ) of co-pigment-anthocyanin complexes that require high energy for degradation reactions ( Fan et al, 2019 ).…”

On the Limits of Anthocyanins Co-Pigmentation Models and Respective Equations

“…Some expressions regarding the complexation models previously reported in the literature and still used by some authors could lead to misunderstandings, − and for this reason, this aspect will be discussed in the following paragraphs.…”