Effect of thermosonication and thermal treatments on phytochemical stability of barberry juice copigmented with ferulic acid and licorice extract

A colorimetry-enhanced tri-functional film with high stability by polyphenol-anthocyanin co-pigmentation/conjugate: New prospect for active intelligent food packaging

A highly stable "tannin-anthocyanin conjugated" trifunctional active intelligent film was developed by incorporating bilberry anthocyanins (BA) as an indicator and tannin acids (TA) as a co-pigment into a sodium alginate-carrageenan polysaccharide matrix (SC-BA/TA). The doping of TA conferred outstanding antioxidant (DPPH scavenging rate > 90%) and antibacterial properties to the film, particularly effective against S. aureus. The SC-BA/TA films effectively blocked UV rays (close to 0%, effectively impeding most UVA, as well as nearly all UVC and UVB) within the range of 200-320 nm. The TA-BA co-pigment effect significantly improved the anthocyanins' storage and color stability (retention rate > 70% under UV and natural light conditions). TA forms conjugate with anthocyanins by π-π stacking and hydrogen bonding interactions with co-pigmentation rate increases of 10.5% and 11.0% for pH 2 and pH 3, respectively. The film exhibited good responsiveness to volatile amines within 4 min, and offered real-time monitoring of beef freshness, as indicated by visualizing color changes (from red to dark yellow color). Furthermore, the integration of the film's RGB value with beef quality via a smartphone App effectively reduces the variability in visual recognition among individuals. To sum up, composite films based on the "tannin-anthocyanin conjugate" approach hold great potential in the field of food freshness monitoring, opening new possibilities for the development of highly stable active smart packaging films.

Exploring the potential utilization of copigmented barberry anthocyanins in ice cream: Focusing on foaming aspects, and melting attributes

Anthocyanins have emerged as promising substitutes for synthetic dyes owing to their color profiles, and potential health-boosting properties. The primary aim of this investigation was to assess the impact of copigmented, and un-copigmented barberry anthocyanins, employed at different concentrations (1, 3, and 5% w/w) as colorants in ice cream. The secondary goal was to investigate the influence of barberry anthocyanins on ice cream foaming characteristics, and melting point. The samples' physicochemical, textural, and organoleptic characteristics, total phenolic, and anthocyanin content, and antioxidant activity were determined. By increasing barberry extract concentrations in the samples, the pH levels (5.81) decreased, and overrun increased(30.0 ± 1.15%), respectively. Furthermore, the textural analysis showed that increasing barberry anthocyanins within the ice cream formulation correlated with an increase in sample hardness (113.72 ± 1.34 N). The control sample (vanilla ice cream) had the highest value of melting rate (1.09 ± 0.03 g/min), whereas the specimen containing 5% of copigmented barberry anthocyanins exhibited the lowest rate of melting (0.50 ± 0.01 g/min). The start time of melting of control sample was 1098 s and by increasing the concentration of copigmented barberry anthocyanins from 1 to 5%, this time increased from 1405.2 s to 1831.2 s (P < 0.05). In conclusion, barberry anthocyanins reduced the melting rate as a crucial attribute for ice cream.

Technologically Driven Approaches for the Integrative Use of Wild Blackthorn (Prunus spinosa L.) Fruits in Foods and Nutraceuticals

Different technological approaches were used in this study for the valorization of blackthorn (Prunus spinosa L.) fruits in marmalade, jam, jelly, and nutraceuticals. Marmalade showed the highest concentrations of polyphenols (7.61 ± 0.05 mg gallic acid equivalents/g dry weight (DW)) and flavonoids (4.93 ± 0.22 mg catechin equivalents/g DW), whereas jam retained the highest content of anthocyanins (66.87 ± 1.18 mg cyanidin-3-O-glucoside equivalents/g DW). A good correlation between polyphenol and flavonoid contents and antioxidant activity was found, the highest value being 21.29 ± 1.36 mmol Trolox/g DW for marmalade. Alternatively, the fresh pulp was enriched with inulin, followed by inoculation with Lactobacillus acidophilus, and freeze-dried, allowing a powder to be obtained with a viable cell content of 6.27 × 107 CFU/g DW. A chromatographic analysis of blackthorn skin revealed that myricetin (2.04 ± 0.04 mg/g DW) was the main flavonoid, followed by (+)-catechin (1.80 ± 0.08 mg/g DW), (-)-epicatechin (0.96 ± 0.02 mg/g DW), and vanillic acid (0.94 ± 0.09 mg/g DW). The representative anthocyanins were cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, and peonidin 3-O-glucoside, with an average concentration of 0.75 mg/g DW. The skin extract showed comparable IC50 values for tyrosinase (1.72 ± 0.12 mg/mL), α-amylase (1.17 ± 0.13 mg/mL), and α-glucosidase (1.25 ± 0.26 mg/mL). The possible use of kernels as calorific agents was demonstrated through the evaluation of calorific power of 4.9 kWh/kg.

Progress on molecular modification and functional applications of anthocyanins

Anthocyanins have attracted a lot of attention in the fields of natural pigments, food packaging, and functional foods due to their color, antioxidant, and nutraceutical properties. However, the poor chemical stability and low bioavailability of anthocyanins currently limit their application in the food industry. Various methods can be used to modify the structure of anthocyanins and thus improve their stability and bioavailability characteristics under food processing, storage, and gastrointestinal conditions. This paper aims to review in vitro modification methods for altering the molecular structure of anthocyanins, as well as their resulting improved properties such as color, stability, solubility, and antioxidant properties, and functional applications as pigments, sensors and functional foods. In industrial production, by mixing co-pigments with anthocyanins in food systems, the color and stability of anthocyanins can be improved by using non-covalent co-pigmentation. By acylation of fatty acids and aromatic acids with anthocyanins before incorporation into food systems, the surface activity of anthocyanins can be activated and their antioxidant and bioactivity can be improved. Various other chemical modification methods, such as methylation, glycosylation, and the formation of pyranoanthocyanins, can also be utilized to tailor the molecular properties of anthocyanins expanding their range of applications in the food industry.

Protective effect of amino acids on the stability of bayberry anthocyanins and the interaction mechanism between l-methionine and cyanidin-3-O-glycoside

The protective effects of three amino acids (l-phenylalanine, l-tryptophan and l-methionine) on the stability of bayberry anthocyanins were investigated. The anthocyanin stability under constant illumination (5000 Lux, 50 Hz) or in the presence of ascorbic acid were evaluated by degradation kinetic parameters, and the interaction between l-methionine and cyanidin-3-O-glucoside (C3G) in a model beverage system was analyzed using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, X-ray diffraction, molecular docking, and molecular dynamics simulation. Results indicated that the three amino acids significantly reduced the degradation rate of bayberry anthocyanins (p < 0.05), with the most effect by l-methionine. l-methionine could bind to C3G via hydrogen bonds and Van der Waals forces. This study suggested that l-methionine could well protect anthocyanin against degradation in the aqueous solution and have the potential to be used as a co-pigment to improve the sensory property and extend the shelf life of anthocyanin rich berry products.

Updated insights into anthocyanin stability behavior from bases to cases: Why and why not anthocyanins lose during food processing

Anthocyanins have received considerable attention for the development of food products with attractive colors and potential health benefits. However, anthocyanin applications have been hindered by stability issues, especially in the context of complex food matrices and diverse processing methods. From the natural microenvironment of plants to complex processed food matrices and formulations, there may happen comprehensive changes to anthocyanins, leading to unpredictable stability behavior under various processing conditions. In particular, anthocyanin hydration, degradation, and oxidation during thermal operations in the presence of oxygen represent major challenges. First, this review aims to summarize our current understanding of key anthocyanin stability issues focusing on the chemical properties and their consequences in complex food systems. The subsequent efforts to examine plenty of cases attempt to unravel a universal pattern and provide thorough guidance for future food practice regarding anthocyanins. Additionally, we put forward a model with highlights on the role of the balance between anthocyanin release and degradation in stability evaluations. Our goal is to engender updated insights into anthocyanin stability behavior under food processing conditions and provide a robust foundation for the development of anthocyanin stabilization strategies, expecting to promote more and deeper progress in this field.

A comprehensive review on innovative and advanced stabilization approaches of anthocyanin by modifying structure and controlling environmental factors

Anthocyanins are pigments abundant in fruits and vegetables, and commonly applied in foods due to attractive colour and health-promoting benefits. However, instability of anthocyanins leads to their easy degradation, reduced bioactivity, and colour fading in food processing, limiting their application and causing economic losses. Stability of anthocyanins depends on their own structures and environmental factors. For structural factors, modification including copigmentation, acylation and biosynthesis is a potential solution to increase anthocyanin stability due to forming stable structures. With regard to environmental factors, encapsulation such as microencapsulation, liposome and nanoparticles has been shown effectively to enhance the stability. We proposed the potential challenges and perspectives for the diversification of anthocyanin-rich products for food application, particularly, introduction of hazards, technical limitations, interaction with other ingredients in food system and exploration of pyranoanthocyanins. The integrated strategies are warranted for improving anthocyanin stabilization for promoting their further application in food industry.

Application of Thermosonication in Red Pitaya Juice Processing: Impacts on Native Microbiota and Quality Properties during Storage

The effects of thermosonication (TS) on microbial safety and quality of red pitaya juice during storage were assessed in this study. Freshly prepared red pitaya juices were thermosonicated at 475 W and 56 °C for 20 min. Upon TS processing, native microbiota including aerobic bacteria, yeasts, and molds reduced to less than 10 CFU/mL. Their growth during storage were slow and equal to thermal-processed (83 °C, 1.5 min) samples. During storage at 4 °C for 28 days, soluble solid content, pH, activities of polyphenol oxidase and peroxidase, and browning degree remained unchanged. A visible color decay was observed in TS-processed samples at day 10, mainly resulting from decomposition of betacyanins and the growth of residual native microbiota. Compared to thermal-treated juices, better color retention was obtained by TS treatment. Therefore, TS is a promising alternative technology of thermal methods of juice processing, with equal shelf life and better quality retention effects.

Gallic acid as a copigment enhance anthocyanin stabilities and color characteristics in blueberry juice

The aim of this study was to evaluate the influence of adding copigment gallic acid (GA) on the stability of anthocyanin and color in blueberry juice, and assays were carried out with different anthocyanin:GA molar ratios (1:0, 1:1, 1:3, 1:5) in accelerated experiments (40 °C for 10 days). Results showed that the addition of GA made blueberry juice to appear more crimson color tonality, color saturation and anthocyanins stability. The most obvious hyperchromic effect appeared in juice with 1:5 of anthocyanin:GA molar ratios, and in this ratio, total anthocyanin content (137.67 mg/L) and main anthocyanin peonidin-3-glucoside content (51.68 mg/L) of the blueberry juice were higher than juice without copigment (total anthocyanin of 116.96 mg/L and peonidin-3-glucoside of 34.2 mg/L). Furthermore, anthocyanins in blueberry juice copigmented with molar ratios 1:5 of anthocyanin:GA were more stable at 4 °C than that at 25 °C and 40 °C. Thus, the addition of gallic acid at appropriate levels might be a promising juice process technology to obtain juices with high color quality and anthocyanin stability.

Stabilization of Black Rice (Oryza Sativa, L. Indica) Anthocyanins Using Plant Extracts for Copigmentation and Maltodextrin for Encapsulation

Black rice (Oryza sativa L. indica) is one of the cereal commodities considered to be a source of anthocyanin. One of the obstacles of using anthocyanins as natural food colorants is their low stability. The objective of this study was to determine the effect of natural plants extracts on anthocyanin copigmentation and to study the stability of the encapsulated copigmented anthocyanin during storage under different temperatures and light exposure. Dried bilimbi leaves (BL) and sow thistle leaves (STL) were extracted using ethanol to obtain the crude flavonoid extract that was subsequently purified using solid phase extraction. Both crude (CBL, CSTL) and purified (PBL, PSTL) extract were used as copigment agents with the molar ratio of 1:0.1 to 1:10 at pH 1 and pH 3. The copigmentation effect was evaluated by measuring the wavelength and absorbance shifts at wavelengths of 500 to 600 nm. The stability of the dried anthocyanin powder was evaluated under different temperatures and light exposure for up to 4 weeks. Anthocyanin was successfully copigmented with BL and STL extracts showing a wavelength shift and absorbance increase at pH 1 and pH 3. Purification of BL enhanced the hyperchromic effect more than that of the crude form, in contrast to the STL. Meanwhile, the retention of absorbance (%) for encapsulated copigmented anthocyanin samples was within 74% to 83% at the end of the storage period. PRACTICAL APPLICATION: Natural food pigment such as anthocyanin obtained from plant extract usually shows very limited stability under various processing conditions. This study shows that color stability of anthocyanin extracted from black rice can be improved by copigmentation with flavonoids extracted from particular plants. Encapsulation of the copigmented anthocyanin could further enhance its color stability. The availability of encapsulated and copigmented anthocyanins with improved color stability is expected to provide more alternatives for especially the beverage industry to choose suitable natural colorant for their products.