Search

Intermolecular copigmentation denotes the interaction between colored anthocyanins and the colorless copigment, which is not bound covalently to the anthocyanin molecule. This is the first study to investigate the effect of intermolecular copigmentation on the stability of individual anthocyanins from dried blackcurrant pomace (DBP) using four pure phenolic acids as copigments (ferulic, caffeic, chlorogenic, and rosmarinic acid). Studies were performed at pH 3.0 and pH 6.0, with a copigment/anthocyanin extract molar ratio of 5:1, during storage at 20 °C. At both pH 3.0 and 6.0, rosmarinic acid showed the strongest hyperchromic and bathochromic effects (p < 0.05) on day 0. However, rosmarinic acid showed low stability during storage. At pH 3.0, chlorogenic acid and control samples were capable of maintaining very high levels of total anthocyanin stability during storage (p < 0.05). On the other hand, ferulic acid and control samples had the longest estimated half-life during storage at pH 6.0. Intermolecular copigmentation successfully increased the half-life, color retention, and antioxidant activity of the anthocyanin solution, with cyanidin-3-O-glucoside (C3G) exhibiting the highest stability at both pH values. Overall, anthocyanins from DBP, in combination with chlorogenic or ferulic acid, showed potential for use in commercial food applications.

The effect of formulation on physiochemical and functional properties of extruded breakfast cereals was investigated. The anthocyanins of breakfast cereals were quantified using HPLC, and remarkable retention of anthocyanins and antioxidant properties was recorded. The purple sweet potato (PSP) indicated a most significant positive impact on antioxidant capacity, whereas the cornflour contributed toward a better expansion of the final product. The optimum formulation of breakfast cereal with an acceptable textural properties and highest antioxidant properties was produced using 55% PSP powder, 15% whole red rice flour, and 30% cornflour and resulted breakfast cereals with hardness, SEI, antioxidant activity, anthocyanin, and total phenolic content of 4.87 kg, 2.93, 13.57 μmol TE/g, 66.35 mg/100 g and 5.13 mg GAE/g, respectively, with attractive natural color, satisfactory bowl‐life and better functional properties. PSP and red rice provide natural color to the final product and rich source of anthocyanins with better antioxidant capacity. Novelty impact statement: The results obtained in this study reveals the potential use of purple sweet potato, whole red rice, and cornflour to formulation of healthy extruded breakfast cereals using a D‐optimal mixture design approach, and resulted breakfast cereals showed better expansion, texture, bowl‐life, and rich in the natural bioactive compound, fiber, and colorants. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of different solvent and extraction temperatures on the free and bound phenolic compounds and antioxidant activity of dried blackcurrant skins (DBS). Apart from acetic acid buffer solution, different solvent systems, including water, methanol, and mixtures of methanol/water, were also employed and the effects of solvent and temperature (30 and 50 °C) on the free and bound forms of anthocyanins, hydroxycinnamic acids, and flavonols yield were assessed. The results showed that among all solvents, acetic acid buffer resulted in the highest free anthocyanin content (1,712.3 ± 56.1 mg/100 g) (P < 0.05) after 2 hr extraction at 50 °C from DBS, while lower amounts of bound anthocyanins and anthocyanidins were detected after acid hydrolysis. Acetic acid buffer extracts exhibited the highest free hydroxycinnamic acid content (268.0 ± 4.5 mg/100 g), total phenolic content (3702.2 ± 259.3 mg GAE/100 g), and DPPH activity (60.7 ± 2.0% of inhibition). However, their free flavonol content was slightly lower (60.2 ± 0.8 mg/100 g) compared to 100% methanol at 30 and 50 °C (71.4 ± 1.5 mg/100 g and 71.5 ± 6.2 mg/100 g, respectively). Two‐way ANOVA indicated interactions between solvent and temperature (P < 0.05), which suggested that the relationship between solvent and phenolic compounds depends on the extraction temperature. Practical Application: Overall, acetic acid buffer is more environmental friendly, efficient, and cost effective than other solvents, thus, offering an improved extraction method for phytochemicals as valuable ingredients for nutraceutical applications, from underutilized dried blackcurrant skins (DBS). [ABSTRACT FROM AUTHOR]

This study investigated the effect of acidified water at different pH values and extraction time on the phenolic profile (anthocyanins, hydroxycinnamic acids and flavonols), antioxidant activity and colour characteristics of dried blackcurrant pomaces (DBP) extracts. Extractions were carried out using acetic acid in water (pH 1.5, 2.0, 2.5 and 3.0) for 2 and 6 h at 30 °C. Phenolics concentration in DBP extracts were influenced by the pH of acidified water (p < 0.05), while extraction pH, extraction time and their combination had significant impact on total phenolics, antioxidant activity and colour of DBP extracts (p < 0.05). Regardless of the extraction time, very low pH (1.5) was positively associated with high amounts of anthocyanins, hydroxycinnamic acids and flavonols in DPB extracts. Also, extracts obtained at pH 1.5 had the highest amount of total phenolics and antioxidant activity. Overall, acetic acid in water as extraction medium may influence greatly the phenolic profile and colour of DBP extracts, which could be utilised as alternative to synthetic food colourants. • Blackcurrant extracts at pH 1.5 were rich in anthocyanins, hydroxycinnamic acids and flavonols. • Extraction time had no effect on the yield of p -coumaric, caffeic and ferulic acids. • Anthocyanins were the highest antioxidant contributors in blackcurrant extracts. • Low extraction pH (1.5–3.0) can tailor the colour properties of blackcurrant extracts. [ABSTRACT FROM AUTHOR]

Purple sweet potato (PSP) is a rich source of anthocyanins, but the anthocyanin content and color can be affected by the drying method and processing condition. Response surface methodology (RSM) with a Box–Behnken design (BBD) was used to investigate the effects of citric acid (CA) concentration, steam pressure (SP) and rotation speed (DS) on the physicochemical and functional properties of drum-dried purple sweet potato powder (PSPP). The anthocyanins of the PSPP were analyzed using mass spectrometry with electrospray ionization and twelve anthocyanins were identified. The results indicated that the moisture content (4.80 ± 0.17–9.97 ± 0.03%) and water activity (0.290 ± 0.004–0.47 ± 0.001) (p < 0.05) decreased with increasing drum temperature as well as with reduced drum rotating speed. CA had a significant (p < 0.05) effect on the color and total anthocyanin content (101.83 ± 2.20–124.09 ± 2.89 mg/100 g) of the PSPP. High SP and low DS negatively affected the antioxidant properties of the PSPP. DPPH value of the PSPP ranged from 20.41 ± 0.79 to 30.79 ± 1.00 μmol TE/g. The optimal parameters were achieved at 0.59% CA, 499.8 kPa SP and 3 rpm DS. [ABSTRACT FROM AUTHOR]