Relative comparisons of extraction methods and solvent composition for Australian blueberry anthocyanins

Enhancing anthocyanin extraction efficiency in vegetables and fruits: a high-speed shear homogenization technology

BACKGROUND

To extract anthocyanins with high efficiency, a hypothesis for high-speed shear homogenization extraction (HSHE) method was established through a combination of solvent and ultrasonic-assisted extractions. The efficacy of this hypothesis was demonstrated by performing qualitative and quantitative analyses of 16 anthocyanins extracted from five northern vegetables, and five berry fruits using ultra-high-performance Q-Exactive Orbitrap tandem mass spectrometry. Single-factor experiments were conducted by varying ethanol concentration, temperature, pH and extraction cycles to determine the optimal conditions for this method.

RESULTS

Optimal extraction conditions (ethanol 70-80%, 40-50 °C, pH 3-4, performed twice) were determined using an HSHE (5 min, 10 000 rpm, 25 °C) assisted shaker (60 min) and ultrasonication (40 kHz, 160 W cm-2, 30 min, 25 °C) procedure. Compared to the traditional non-HSHE method, the total anthocyanin content obtained through HSHE extraction showed a significant increase, ranging from 1.0 to 3.9 times higher, with purple cabbage exhibiting the most pronounced enhancement in content. More types of anthocyanins were detected in blueberry (9), black bean (7) and raspberry (5), of which malvidin was the major anthocyanin (0.426 g kg-1) in blueberry, having an amount five times than previously obtained.

CONCLUSION

The established HSHE method has been proven to be a superior technique for anthocyanin extraction, with higher extraction efficiency and concentrations. This technique also provides a new avenue for extracting bioactive compounds from diverse food sources, with potential applications in improving the functional properties of food products. © 2024 Society of Chemical Industry.

Unveiling the multifaceted world of anthocyanins: Biosynthesis pathway, natural sources, extraction methods, copigmentation, encapsulation techniques, and future food applications

Numerous datasets regarding anthocyanins have been noted elsewhere. These previous studies emphasized that all processes must be carried out meticulously from the source used to obtain anthocyanins to their inclusion in relevant applications. However, today, full standardization has not yet been achieved for these processes. For this, presenting the latest developments regarding anthocyanins under one roof would be a useful approach to guide the scientific literature. The current review was designed to serve the stated points. In this context, their biosynthesis pathway was elaborated. Superior potential of fruits and certain by-products in obtaining anthocyanins was revealed compared to their other counterparts. Health-promoting benefits of anthocyanins were detailed. Also, the situation of innovative techniques (ultrasound-assisted extraction, subcritical water extraction, pulse electrical field extraction, and so on) in the anthocyanin extraction was explained. The stability issues, which is one of the most important problems limiting the use of anthocyanins in applications were discussed. The role of copigmentation and various encapsulation techniques in solving these stability problems was summarized. This critical review is a map that provides detailed information about the processes from obtaining anthocyanins, which stand out with their functional properties, to their incorporation into various systems.

Study of UV-Vis molar absorptivity variation and quantitation of anthocyanins using molar relative response factor

The effects of anthocyanin's substitution groups on the UV-Vis molar absorptivity were examined by analyzing a group of 31 anthocyanidin/anthocyanin reference standards with ultra-high performance liquid chromatography-diode array detector (UHPLC-DAD). The substitution groups on aglycones were found to associate with molar absorptivity variations, often neglected in anthocyanin quantitation, resulting in significant analytical errors. A simple yet comprehensive strategy based on the molar relative response factors (MRRFs) and a single master reference calibration (i.e., cyanidin-3-glucoside) was proposed to quantify anthocyanins in red cabbage, blueberry, and strawberry samples with improved analytical accuracy. The results indicate this approach provides an effective, inexpensive, and accurate analytical method for anthocyanins in food materials without using individual reference standards. MRRFs of 617 anthocyanins/anthocyanidins were calculated, and the information is freely available at https://BotanicalDC.online/anthocyanin/. This study could be critical to developing new reference methods for anthocyanin analysis and harmonizing results and data from various sources.

Investigating the Therapeutic Potential of Plants and Plant-Based Medicines: Relevance to Antioxidant and Neuroprotective Effects

Oxidative stress is a common characteristic of psychiatric, neurological, and neurodegenerative disorders. Therefore, compounds that are neuroprotective and reduce oxidative stress may be of interest as novel therapeutics. Phenolic, flavonoid and anthocyanin content, ORAC and DPPH free radical scavenging, and Cu2+ and Fe2+ chelating capacities were examined in variations (fresh/capsule) of Queen Garnet plum (QGP, Prunus salicina), black pepper (Piper nigrum) clove (Syzygium aromaticum), elderberry (Sambucus nigra), lemon balm (Melissa officinalis) and sage (Salvia officinalis), plus two blends (Astralagus membranaceus-lemon balm-rich, WC and R8). The ability of samples to prevent and treat H2O2-induced oxidative stress in SH-SY5Y cells was investigated. Pre-treatment with WC, elderberry, QGP, and clove prevented the oxidative stress-induced reduction in cell viability, demonstrating a neuroprotective effect. Elderberry increased cell viability following oxidative stress induction, demonstrating treatment effects. Clove had the highest phenolic and flavonoid content, DPPH, and Cu2+ chelating capacities, whereas QGP and elderberry were highest in anthocyanins. Black pepper had the highest ORAC and Fe2+ chelating capacity. These findings demonstrate that plant extracts can prevent and treat oxidative stress-induced apoptosis of neuron-like cells in vitro. Further research into phytochemicals as novel therapeutics for oxidative stress in the brain is needed.

An Optimized HPLC-DAD Methodology for the Determination of Anthocyanins in Grape Skins of Red Greek Winegrape Cultivars (Vitis vinifera L.)

A rapid and simple HPLC-DAD analytical method was developed and optimized for the determination of anthocynanins in three red Greek winegrape varieties (Kotsifali, Limnio, and Vradiano). The critical parameters, such as the acidifying solvent and the extraction temperature, which affect the extraction of anthocyanins from the grapes, were studied to find the optimum values. The developed methodology was validated in terms of selectivity, linearity, accuracy, and precision and presented satisfactory results. The limits of quantification (LOQs) ranged between 0.20 mg/kg to 0.60 mg/kg, and the limits of detection (LODs) ranged between 0.06 mg/kg and 0.12 mg/kg. The RSD% of the within-day and between-day assays were lower than 6.2% and 8.5%, respectively, showing adequate precision. The accuracy ranged between 91.6 and 119% for within-day assay and between 89.9 and 123% for between-day assay. Sixteen samples from the main regions of each variety as well as from the official ampelographic collections of Greece were collected during the 2020 growing season and were further analyzed by HPLC-DAD. Notable differences in the anthocyanin content were detected among the cultivars using hierarchical cluster analysis (HCA).