Anthocyanins degradation during storage of Hibiscus sabdariffa extract and evolution of its degradation products

Trend in Detection of Anthocyanins from Fresh Fruits and the Influence of Some Factors on Their Stability Impacting Human Health: Kinetic Study Assisted by UV-Vis Spectrophotometry

Anthocyanins (ANTHs) are polyphenolic compounds with health promoting properties, being known for their strong antioxidant effects as well as for their antimicrobial properties, obesity and cardiovascular disease prevention, and anticarcinogenic activity. Being main dietary components, it is important to know the content of anthocyanins in various dietary sources and their stability in time. The total anthocyanin content (TAC) of various fresh fruits has been spectrophotometrically determined using the pH differential method. The results showed that in the analyzed samples, the TAC increased in the order: blackcurrants > blackberries > blueberries > raspberries > strawberries > plums. The degradation degree of anthocyanins extracted from blueberries (BBEs) in an ethanol/water solution in four experimental conditions was studied. Kinetic studies have been approached, fitting the experimental data recorded by UV-Vis spectrophotometric analysis in agreement with some kinetic models verified for the ANTH degradation reaction. Therefore, zero-order kinetics for BBE extract degradation exposed to sunlight were identified, while for the other storage conditions (shadow, dark, cold), the first-order kinetics were respected. The results indicate that the stability decreased as follows: (ANTH stability)sunlight test << (ANTH stability)shadow test ≈ (ANTH stability)dark test < (ANTH stability)cold test. A mechanism for BBE anthocyanin degradation was proposed and the impact on human health of the degradation products is discussed.

Nano-targeted delivery system: a promising strategy of anthocyanin encapsulation for treating intestinal inflammation

Anthocyanins are natural flavonoids derived from plants, widely recognized for their health-promoting effects, specifically to treat inflammatory bowel disease (Crohn's disease and ulcerative colitis). However, certain limitations are associated with their use, including instability, low solubility and permeability, poor gastrointestinal digestion, and low bioavailability. In this review, nano-carriers (e.g., liposome, polymersome, exosome, halloysite nanotubes, dendrimer, and nano-niosome, etc.) were summarized as anthocyanins delivery vehicles to treat inflammatory bowel disease. Recent progress on emerging strategies involved surface functionalization, responsive release, magnetic orientation, and self-assembly aggregation to address intestinal inflammation through nano-carriers and potential mechanisms were discussed. Anthocyanins, water-soluble pigments linked by glycoside bonds have attracted attention to alleviate intestinal inflammation related diseases. Anthocyanins can address intestinal inflammation by exerting their health beneficial effects such as anti-oxidative, anti-inflammatory, regulating the intestinal flora, and promoting apoptosis. Moreover, nano-carriers were discussed as oral delivery system for maximized bioefficacy of anthocyanins and to address concerns related to their low solubility and permeability, poor gastrointestinal metabolism, and low bioavailability were discussed. A future perspective is proposed concerning anthocyanin-loaded nano-carriers, different strategies to improve their efficacy, and developing functional food to treat intestinal inflammation.

Exploring acylated anthocyanin-based extracts as a natural alternative to synthetic food dyes: Stability and application insights

This work explores the potential of anthocyanin-based extracts (hibiscus calyxes - HC, red cabbage - RC, and butterfly pea flower - BPF) as natural alternatives to synthetic dyes in the food industry. Analyses in a pH range for food applications revealed higher color stability for the BPF extract, keeping vibrant colors over the 7 days at room temperature. At pH 3 and 100 °C, the BPF was more stable, losing half of its anthocyanin concentration after 14 h, while RC and HC lost half of their color after 7 and 2 h, respectively. The bisulfite bleaching followed a second-order reaction for HC and RC, and a first-order reaction for BPF, suggesting a minor effect of the bisulfite on this extract. Incorporating these extracts into porcine protein and agar-agar gelatin formulations produced consistent products with appealing hues, particularly the blue and purple colors for BPF and RC, dependent on the pH.

Stability of anthocyanin extracts from chokeberry, grape, hibiscus, and purple sweet potato in ω-3-fatty acid rich oil-in-water emulsions

The food industry is actively investigating the stability of natural red pigments to replace artificial food colorants from all food applications in the near future. In this study, the stability of coloring extracts from chokeberry, grape, hibiscus, and purple sweet potato was investigated in ω-3 fatty acid-rich flaxseed oil-in-water emulsion during storage. The red color of the oil-in-water emulsions faded within 4 days, indicating that the anthocyanin extracts were susceptible to lipid oxidation reactions of the ω-3 fatty acids. The color stability varied between all used extract sources: The chokeberry (degradation constant k = 19.6 h-1) and grape (k = 15.2 h-1) extracts showed similar degradation kinetics, whereas purple sweet potato extract (k = 10.7 h-1) degraded significantly slower, and hibiscus extract (k = 110.2 h-1) significantly faster. The differences can be explained by the different anthocyanins contained in the plant extract, especially by the proportion of acylated anthocyanins.

Floating metal phthalocyanine@polyacrylonitrile nanofibers for peroxymonosulfate activation: Synergistic photothermal effects and highly efficient flowing wastewater treatment

Highly efficient floating photocatalysis has potential applications in organic pollutant treatment but remains limited by low degradation efficiency in practical applications. By introducing the photothermal effect into a peroxymonosulfate (PMS) coupled photocatalysis system, tetracycline hydrochloride (TCH) degradation could be significantly enhanced using floating metal phthalocyanine@polyacrylonitrile (MPc@PAN) nanofiber mats. MPc@PAN nanofibers with different metal centers showed similar photothermal conversion performance but different activation energies for PMS activation, resulting in metal-center-dependent synergistic photothermal effects, i.e., light-enhanced dominated, thermal-enhanced dominated, and conjointly light-thermal dominated mechanisms. The porous structures and floating ability of the FePc@PAN nanofibers provided a fast mass transfer process, with higher solar energy utilization and superior photothermal conversion performance than the FePc nanopowders. Meanwhile, the FePc@PAN nanofibers showed excellent TCH removal stability within 10 cycles (>92%) and extremely low Fe ion leaching (<0.055 mg/L) in a dual-channel flowing wastewater treatment system. This work provides new insight into PMS activation via photothermal effects for environmental remediation.

Protein and Peptide-Based Nanotechnology for Enhancing Stability, Bioactivity, and Delivery of Anthocyanins

Anthocyanin, a unique natural polyphenol, is abundant in plants and widely utilized in biomedicine, cosmetics, and the food industry due to its excellent antioxidant, anticancer, antiaging, antimicrobial, and anti-inflammatory properties. However, the degradation of anthocyanin in an extreme environment, such as alkali pH, high temperatures, and metal ions, limits its physiochemical stabilities and bioavailabilities. Encapsulation and combining anthocyanin with biomaterials could efficiently stabilize anthocyanin for protection. Promisingly, natural or artificially designed proteins and peptides with favorable stabilities, excellent biocapacity, and wide sources are potential candidates to stabilize anthocyanin. This review focuses on recent progress, strategies, and perspectives on protein and peptide for anthocyanin functionalization and delivery, i.e., formulation technologies, physicochemical stability enhancement, cellular uptake, bioavailabilities, and biological activities development. Interestingly, due to the simplicity and diversity of peptide structure, the interaction mechanisms between peptide and anthocyanin could be illustrated. This work sheds light on the mechanism of protein/peptide-anthocyanin nanoparticle construction and expands on potential applications of anthocyanin in nutrition and biomedicine.

Development of a pH-sensing indicator for shrimp freshness monitoring: Curcumin and anthocyanin-loaded gelatin films

An intelligent pH-sensing indicator containing Roselle (Hibiseus sabdariffa L.) (RS) anthocyanin and curcumin (CR) was developed and characterized as on-package indicator tags to check the freshness of shrimp during the storage at 4°C. FE-SEM and FT-IR analysis showed that RS and CR were successfully immobilized in the gelatin-glycerol film-forming substrate. The addition of various natural dyes increased the thickness and antioxidant action of the colorimetric film. To assess the response to changes in the pH, the colorimetric film was immersed in different buffers. Based on volatile amines secreted by shrimp, a test application of a colorimetric film containing natural dyes at a ratio of CR:RS = 1:4 (v/v) was conducted in shrimp at 4°C. The total volatile basic nitrogen (TVB-N) and the pH of shrimp were monitored during refrigerated storage for 10 days, and the color changes of the indicator were recorded simultaneously. The results indicated that the designed colorimetric film could produce various colors, which are thought to be indicative of the freshness and spoilage of packaged shrimp. Therefore, the target film can be utilized as a promising smart packaging material for monitoring the freshness of shrimp and aquatic products in real time.

Recovery of Anthocyanins from Hibiscus sabdariffa L. Using a Combination of Supercritical Carbon Dioxide Extraction and Subcritical Water Extraction

Anthocyanins are one of the bioactive compounds in roselle that has many medicinal proposes. Anthocyanins are placed in the inner part of the roselle; therefore, combinations of two methods were applied to extract the anthocyanins. The first stage is employing supercritical carbon dioxide (ScCO2) to break the particle surface or outer layer of the roselle based on the total phenolic compounds (TPC) recovery, and the second step was to apply subcritical water extraction (SWE) for the extraction of anthocyanins. The objective is to determine the best conditions to obtain high yields of total anthocyanins compounds (TAC) from the roselle (Hibiscus sabdariffa) by employing a combination of ScCO2 and SWE. The optimal conditions of ScCO2 (first stage) were 19.13 MPa, 60 °C, and 4.31 mL/min, yielding 18.20%, and 80.34 mg/100 g TPC, respectively. The optimum conditions of SWE (second stage) were 9.48 MPa, 137 °C, and 6.14 mL/min, yielding 86.11% and 1224.61 mg/100 g TAC, respectively. The application of integrated ScCO2 and SWE proved successful in achieving high anthocyanins production and yield as compared to previous extraction methods. This approach may be used to extract the roselle with a greater anthocyanin’s concentration than the prior method.

Synergistic Antibacterial Proficiency of Green Bioformulated Zinc Oxide Nanoparticles with Potential Fosfomycin Synergism against Nosocomial Bacterial Pathogens

The drug resistance of bacterial pathogens causes considerable morbidity and death globally, hence there is a crucial necessity for the development of effective antibacterial medicines to address the antibacterial resistance issue. The bioprepared zinc oxide nanoparticles (ZnO-NPs) were prepared utilizing the flower extract of Hibiscus sabdariffa and then characterized using different physicochemical techniques. The antibacterial effectiveness of the bioprepared ZnO-NPs and their synergism with fosfomycin were evaluated using disk diffusion assay against the concerned pathogens. Transmission electron microscopy (TEM) investigation of the bioprepared ZnO-NPs showed that their average particle size was 18.93 ± 2.65 nm. Escherichia coli expressed the highest sensitivity to the bioinspired ZnO-NPs with a suppressive zone of 22.54 ± 1.26 nm at a concentration of 50 µg/disk, whereas the maximum synergistic effect of the bioinspired ZnO-NPs with fosfomycin was noticed against Klebsiella pneumoniae strain with synergism ratio of 100.29%. In conclusion, the bioinspired ZnO-NPs demonstrated significant antibacterial and synergistic efficacy with fosfomycin against the concerned nosocomial bacterial pathogens, highlighting the potential of using the ZnO NPs-fosfomycin combination for effective control of nosocomial infections in intensive care units (ICUs) and health care settings. Furthermore, the biogenic ZnO-NPs’ potential antibacterial action against food pathogens such as Salmonella typhimurium and E. coli indicates their potential usage in food packaging applications.

Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based metabolomics to clarify the mechanism of color change of saffron floral bio-residues

Saffron floral bio-residues (SFB) are a valuable natural source of antioxidants and dyes that can contribute to the development of new food products and cosmetic products. Color change was usually observed during SFB storage, which may result in quality degradation of SFB or even cause potential hazard to human health. In order to clarify the mechanism of color change of SFB sample, the chemical differences among SFB samples stored under different conditions were analyzed using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and chemometrics methods, from which differential flavonols and anthocyanins were screened and their kinetic variations during sample storage summarized. In addition, the color change of the SFB sample was digitalized using an electronic eye (E-eye), which was found to be related to the content of delphinidin-3,5-di-O-glucoside (DDG). Moreover, the degradation kinetic parameters of DDG under different storage conditions were studied. In conclusion, the variation of kaempferol-, isorhamnetin-, and quercetin-type flavonol, and delphinidin- and petunidin-type anthocyanin resulted in the color change of SFB sample, and anthocyanin was found more unstable than flavonol. PRACTICAL APPLICATION: Saffron floral bio-residues (SFB) are popular natural sources of antioxidants and colorants that can be used in food and cosmetic products. Color change usually occurs during SFB storage period. Clarifying the mechanism of the color change of SFB will help us to ensure the quality of SFB.

Insight into Green Extraction for Roselle as a Source of Natural Red Pigments: A Review

Roselle (Hibiscus sabdariffa L.) is a source of anthocyanins as red pigments that is extensively farmed in tropical and subtropical regions, including Indonesia, Malaysia, China, Thailand, Egypt, Mexico, and West India. The roselle plant contains a variety of nutrients, including anthocyanins, organic acids, pectin, etc. Due to the toxicity and combustibility of the solvents, traditional extraction methods for these compounds are restricted. Obtaining pure extracts is typically a lengthy procedure requiring many processes. Supercritical carbon dioxide (ScCO₂) extraction as a green technology is rapidly improving and extending its application domains. The advantages of this method are zero waste production, quicker extraction times, and reduced solvent consumption. The ScCO₂ extraction of natural pigments has great promise in food, pharmaceuticals, cosmetics, and textiles, among other uses. The ScCO₂ technique for natural pigments may also be advantageous in a variety of other contexts. Due to their minimal environmental risk, the high-quality red pigments of roselle rich in anthocyanins extracted using ScCO₂ extraction have a high sustainability potential. Therefore, the objective of this review is to increase knowledge related to the natural colorant of roselle as a substitute for chemically manufactured colorants using ScCO₂ as a green method. This article covers ScCO₂ extraction, particularly as it relates to the optimization of pigments that promote health. This article focuses on the high extraction efficiency of ScCO₂ extraction. Natural colorants extracted via ScCO₂ are regarded as safe compounds, especially for human consumption, such as novel functional food additives and textile and pharmaceutical colors.

Gelatin-Based Film as a Color Indicator in Food-Spoilage Observation: A Review

The color indicator can monitor the quality and safety of food products due to its sensitive nature toward various pH levels. A color indicator helps consumers monitor the freshness of food products since it is difficult for them to depend solely on their appearance. Thus, this review could provide alternative suggestions to solve the food-spoilage determination, especially for perishable food. Usually, food spoilage happens due to protein and lipid oxidation, enzymatic reaction, and microbial activity that will cause an alteration of the pH level. Due to their broad-spectrum properties, natural sources such as anthocyanin, curcumin, and betacyanin are commonly used in developing color indicators. They can also improve the gelatin-based film's morphology and significant drawbacks. Incorporating natural colorants into the gelatin-based film can improve the film's strength, gas-barrier properties, and water-vapor permeability and provide antioxidant and antimicrobial properties. Hence, the color indicator can be utilized as an effective tool to monitor and control the shelf life of packaged foods. Nevertheless, future studies should consider the determination of food-spoilage observation using natural colorants from betacyanin, chlorophyll, and carotenoids, as well as the determination of gas levels in food spoilage, especially carbon dioxide gas.

Active and pH-Sensitive Nanopackaging Based on Polymeric Anthocyanin/Natural or Organo-Modified Montmorillonite Blends: Characterization and Assessment of Cytotoxicity

Polymeric anthocyanins are biologically active, pH-sensitive natural compounds and pigments with beneficial functional, pharmacological and therapeutic properties for consumer health. More recently, they have been used for the manufacture of active and pH-sensitive ("intelligent") food nanopackaging, due to their bathochromic effect. Nevertheless, in order for polymeric anthocyanins to be included either as a functional food or as a pharmacological additive (medicinal food), they inevitably need to be stabilized, as they are highly susceptible to environmental conditions. In this regard, nanopackaging has become a tool to overcome the limitations of polymeric anthocyanins. The objective of this study was to evaluate their structural, thermal, morphological, physicochemical, antioxidant and antimicrobial properties, as well as their responses to pH changes, and the cytotoxicity of blends made from polymeric anthocyanins extracted from Jamaica flowers (Hibiscus sabdariffa) and natural or organo-modified montmorillonite (Mt), as active and pH-sensitive nanopackaging. This study allowed us to conclude that organo-modified Mts are efficient pH-sensitive and antioxidant nanopackaging systems that contain and stabilize polymeric anthocyanins compared to natural Mt nanopackaging and stabilizing polymeric anthocyanins. However, the use of these polymeric anthocyanin-stabilizing organo-modified Mt-based nanopackaging systems are limited for food applications by their toxicity.

Ultrasound-Assisted Natural Deep Eutectic Solvents Extraction of Bilberry Anthocyanins: Optimization, Bioactivities, and Storage Stability

Bilberry fruits (Vaccinium myrtillus L.) are one of the richest natural sources of anthocyanins and are widely used due to their pharmacological and nutritional properties. To ensure their maximum application potential, it is necessary to overcome the limitations of conventional extraction solvents and techniques. This study aimed to develop a green method for bilberry anthocyanin extraction using natural deep eutectic solvents (NaDES) integrated with ultrasound-assisted extraction (UAE) in order to define extraction conditions that will prevent decomposition of the anthocyanins or the loss of bioactivity. After a screening of ten different NaDES, choline chloride:sorbitol (1:1) was selected as the most effective. Furthermore, the influence analysis and optimization of the NaDES-UAE extraction conditions were carried out employing response surface methodology. The optimal conditions were found to be an extraction time of 37.63 min, a temperature of 48.38 °C, and 34.79% (w/w) water in NaDES. The extraction yields of target compounds under optimized extraction conditions were 0.27 mg/g DW of cyanidin-3-O-glucoside and 2.12 mg CGE/g DW of TAC. The obtained optimized extract showed promising radical scavenging and antimicrobial activity. A stability study with the optimized extract revealed that refrigerated storage at 4 °C in the dark provided the best anthocyanins preservation. Overall, the developed NaDES-UAE method showed promising application potential and can be considered as a high-efficiency green alternative to conventional anthocyanins extraction methods, enabling the preservation of active ingredients and the bioactivity of extracts.

Stability Enhancement of Anthocyanins from Blackcurrant (Ribes Nigrum L.) Pomace through Intermolecular Copigmentation

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.

Development of nanofiber indicator with high sensitivity for pork preservation and freshness monitoring

A visual Polyvinylidene Fluoride (PVDF) fibrous film incorporated with Roselle anthocyanin (RS) and Cinnamon essential oil (CEO) (PRC film) was designed via electrospinning technology for pork preservation and freshness monitoring. The PRC film presented well structural integrity and stability in buffer solutions without leaking out RS. And PCR film had well hydrophobic and high permeability with water contact angle (WCA) of 109.52° and water vapor permeability (WVP) of 2.63 × 10^-7 g m^-1h^-1Pa^-1. Importantly, PRC film exhibited good antibacterial activity with the inhibition diameter at 29.0 mm and 27.1 mm which against Escherichia coli and staphylococcus aureus, respectively. Finally, the PRC film was employed as a colorimetric sensor for monitoring pork freshness. It presented visible color changes from pink to blue and effectively prolonged the pork shelf-life by 2 days at 4 °C. These results indicate a great potential in intelligent and active packaging.

Improvement on blood pressure and skin using roselle drink: A clinical trial

Roselle (Hibiscus sabdariffa L.) is an increasingly attractive plant for its health and pharmaceutical, beverage, and cosmetic applications. The purpose of this study was to investigate the clinical effects of roselle drink on antioxidant activity, blood pressure, and skin condition. Roselle drink used in this study contained rich phenolics (1.96 g of gallic acid equivalent/100 ml) and anthocyanins (1.65 g of cyanidin-3-glucoside equivalent/100 ml). In a randomized, cross-over, double-blind, placebo-controlled clinical study, 39 healthy adults received drank 200 ml of roselle drink or placebo-control drink for 6 months. A significant reduction in the blood pressure was observed in the roselle drink treated group when compared with preintervention values. After 6 months of treatment with roselle drink, serum phenolics contents, the levels of Trolox equivalent antioxidant capacity (TEAC), glutathione, superoxide dismutase (SOD), glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase (GSH-Px), and glutathione reductase (GSH-Rd) were significantly increased in healthy subjects. However, a significant increment in skin redness and skin moisture was observed in the facial skin of roselle drink-treated participants. Oral administration of roselle drink for 6 months significantly lowered the blood pressure, improved antioxidation level, and positively regulated skin redness as well as moisture. Phenolics and anthocyanins in roselle could be the major potential contributors to such health effects. PRACTICAL APPLICATIONS: Roselle is a typical plant. Continuous administration of roselle drink clearly improved antioxidation levels, reduced blood pressure and positively regulated skin redness and moisture. Phenloics and anthocyanins in roselle could be the major potentila contributors of such health benefits.

The non-covalent interactions between whey protein and various food functional ingredients

In daily diet, Whey protein (WP) is often coexisted with various Food functional ingredients (FFI) such as proteins, polyphenols, polysaccharides and vitamins, which inevitably affect or interact with each other. Generally speaking, they may be interact by two different mechanisms: non-covalent and covalent interactions, of which the former is more common. We reviewed the non-covalent interactions between WP and various FFI, explained the effect of each WP-FFI interaction, and provided possible applications of WP-FFI complex in the food industry. The biological activity, physical and chemical stability of FFI, and the structure and functionalities of WP were enhanced through the non-covalent interactions. The development of non-covalent interactions between WP and FFI provides opportunities for the design of new ingredients and biopolymer complex, which can be applied in different fields. Future research will further focus on the influence of external or environmental factors in the food system and processing methods on interactions.

Detailed investigation of the composition and transformations of phenolic compounds in fresh and fermented Vaccinium floribundum berry extracts by high-resolution mass spectrometry and bioinformatics

INTRODUCTION

Blueberries are known for their very high content of biologically active phenolic compounds; nonetheless, differently from the North American and European species of blueberries, Neotropical blueberries have not been extensively studied yet.

OBJECTIVES

In the present paper, the phenolic composition of Vaccinium floribundum Kunth, which is endemic to the Andean regions and grows 1,600 to 4,500 meters above sea level, was investigated by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS). Native and fermented berries were compared in terms of phenolic composition as well as antioxidant activity, total phenolic content, and total anthocyanin content.

MATERIALS AND METHODS

V. floribundum native and fermented berries were extracted and analyzed by UHPLC-HRMS. The acquired datasets were processed by Compound Discoverer 3.1 using a dedicated data analysis workflow that was specifically set up for phenolic compound identification.

RESULTS

In total, 309 compounds were tentatively identified, including anthocyanins, flavonoids, phenolic acids, and proanthocyanidins. The molecular transformations of phenolic compounds during fermentation were comprehensively investigated for the first time, and by a customized data processing workflow, 13 quinones and quinone methides were tentatively identified in the fermented samples. Compared to other species of the genus Vaccinium, a peculiar phenolic profile is observed, with low abundance of highly methylated compounds.

CONCLUSION

Andean berries are a rich source of a wide variety of phenolic compounds. Untargeted MS analyses coupled to a dedicated data processing workflow allowed expanding the current knowledge on these berries, improving our understanding of the fate of phenolic compounds after fermentation.

Physiological Effects and Human Health Benefits of Hibiscus sabdariffa: A Review of Clinical Trials

Hibiscus sabdariffa Linn. Malvaceae (HS) is characterized by its edible calyxes. The HS calyxes are widely used for cosmetic, food, and medicinal applications. According to ethnobotanical evidence, decoction, infusion, or maceration extracts from HS calyxes have been used in folk medicine to treat many ailments. Moreover, several in vitro and in vivo studies have demonstrated the pharmacological properties and potential human health benefits of HS consumption. On the other hand, the evaluation of the physiological effects and health benefits of HS in clinical studies is most challenging. Therefore, this narrative review summarizes and discusses the physiological effects and health benefits of HS calyxes reported in clinical trials. Preparations obtained from HS calyxes (extracts, infusions, decoction, teas, beverages, capsules, and pills) are used as non-pharmacological therapies to prevent/control diverse chronic non-communicable diseases. The most-reported HS health benefits are its antihypertensive, antidyslipidemic, hypoglycemic, body fat mass reduction, nephroprotective, antianemic, antioxidant, anti-inflammatory, and anti-xerostomic activities; these effects are associated with the phytochemicals found in HS. Moreover, no adverse effects were reported during the clinical trials. However, clinical studies exhibited some limitations; thus, further studies are required to validate the clinical efficacy of HS in large-scale studies with higher doses and a good experimental design

Effects of Cryoconcentrated Blueberry Juice as Functional Ingredient for Preparation of Commercial Confectionary Hydrogels

Hydrogels can absorb and/or retain components in the interstitial spaces due to the 3D cross-linked polymer network, and thus, these matrices can be used in different engineering applications. This study focuses on the physicochemical and textural properties, as well as bioactive compounds and their antioxidant activity stability of commercial hydrogels fortified with cryoconcentrated blueberry juice (CBJ) stored for 35 days. CBJ was added to commercial hydrogels (gelatin gel (GG), aerated gelatin gel (AGG), gummy (GM), and aerated gummy (AGM)). The samples showed a total polyphenol, anthocyanin, and flavonoid content ranging from 230 to 250 mg GAE/100 g, 3.5 to 3.9 mg C3G/100 g, and 120 to 136 mg CEQ/100 g, respectively, and GG and GM showed the lowest bioactive component degradation rate, while AGM presented the highest degradation. GG and GM samples could be stored for up to 21 days without significant changes, while the results indicated ≈15 days for the AGG and AGM samples. Thereby, CBJ offers enormous possibilities to be used as a functional ingredient due to the high nutritional values, and it allows enriching different hydrogel samples, and in turn, the structures of hydrogels protected components during in vitro digestion, enhancing the bioaccessibility after the digestion process.

Effect of high-pressure processing and thermal treatments on color and in vitro bioaccessibility of anthocyanin and antioxidants in cloudy pomegranate juice

In this study, the effect of high-pressure processing (HPP) and thermal treatments, including pasteurization (PT) and high-temperature short-time sterilization (HTST) on pomegranate juice (PJ) color attributes, anthocyanin (ACNs), vitamin C, and in vitro bioaccessibility of ACNs and antioxidants were investigated. Compared to HPP, thermal treatments significantly changed the CIE color, decreased the total monomeric ACNs and total vitamin C contents, and increased the percent polymeric color (PPC) and browning index (BI). Correlation analysis showed that the generation of polymeric ACNs played a significant role in color change during thermal treatments. The recovery of 7 ACNs in the control sample after in vitro gastrointestinal digestion was ranged from 0.43% to 5.0% and total individual ACNs after digestion showed no significant changes among different treatments. These results contributed to promoting the color quality and health benefits of pomegranate juice rich in ACNs by optimizing the processing conditions in the food industry.

Cyanidin-3-O-glucoside, cyanidin, and oxidation products of cyanidin protect neuronal function through alleviating inflammation and oxidative damage

Neurotoxicity seriously affects the normal function of the nervous system. Cyanidin-3-O-glucoside (C3G) is the most abundant anthocyanin widely distributed in plants. Using β-amyloid (Aβ) transgenic Caenorhabditis elegans and cell models, the neuroprotective effect of C3G was examined. The results showed that C3G remarkably suppressed Aβ aggregation, enhanced antioxidant capacity, improved the sensitive capacity towards chemical compounds, and boosted the memory ability of C. elegans. There was no significant difference between preventive and long-term treatment groups at the same dosage of C3G. Given the rapid metabolism and oxidation of C3G in vivo, the antioxidative and anti-inflammatory activities of C3G, the metabolite cyanidin (Cy), oxidation products of Cy (OP), as well as protocatechuic acid (PCA) at the corresponding level in OP were compared by using lipopolysaccharide (LPS)-stimulated BV2 microglia cell model. The results indicated that C3G, Cy, and OP could prevent BV2 cells against LPS-induced inflammation and oxidative damage. There was no significant difference on antioxidative and anti-inflammatory activities among C3G, Cy, and OP at the same level. Notably, PCA at the corresponding concentration in OP exhibited limited antioxidative and anti-inflammatory activities. The results suggested that C3G could exert neuroprotective function through the metabolite Cy and its oxidation products by inhibiting inflammation and oxidative damage, and PCA was not the primary bioactive species in OP. PRACTICAL APPLICATION: This study confirmed the neuroprotection of cyanidin-3-O-glucoside (C3G) in transgenic Caenorhabditis elegans. C3G, its metabolite cyanidin (Cy), and oxidation products of Cy (OP) alleviated both neuroinflammation and oxidative damage. It highlighted that C3G-rich foods could exert neuroprotective potential through their oxidation products, the constitution, and existence of OP in vivo need further study.

Ixiolirion tataricum anthocyanins-loaded biocellulose label: Characterization and application for food freshness monitoring

A new intelligent pH-sensitive colorimetric label was fabricated by immobilizing Ixiolirion tataricum anthocyanins (ITA) into biocellulose (bacterial nanocellulose; BNC) film and was then studied to determine how it can be used as a label for monitoring freshness/spoilage of shrimp during storage at 4 °C. The formation of new interactions between ITA and BNC film and disruption of crystalline structure of BNC after anthocyanins immobilization were approved by FT-IR and XRD analyses, respectively. According to FE-SEM observations, the porosity of the BNC network decreased after ITA incorporation. The fabricated BNC-ITA label showed a distinct color change from violet to green over the pH range of 4-12. The pH, total volatile basic nitrogen (TVB-N), total psychrophiles count (TPC), and the quantity of biogenic amines (histamine, cadaverine, putrescine, and tyramine) in the shrimp samples and their correlation with color changes on the label were measured over a 4-day storage period. Consistent with changes in levels of TVB-N, TPC, pH, and biogenic amines, a visually distinguishable color change occurred on the BNC-ITA label as blue (fresh), dark green (medium fresh), and kelly green (spoiled). This research showed that ITA as a novel pH-sensitive dye is a promising candidate for developing pH labels for seafood intelligent packaging.

Microencapsulation of Hibiscus sabdariffa L. Calyx Anthocyanins with Yeast Hulls

Yeast hulls, due to their specific thin mannoprotein layer and high content of β-glucan, constitute a promising material to stabilise the colour of anthocyanins. This study evaluates the potential of yeast hulls on the freeze-drying encapsulation of anthocyanins-rich extract from Hibiscus sabdariffa L. calyx with comparison to maltodextrin microcapsules. The moisture content (5.28-16.38%), water activity (< 0.039-0.307) and hygroscopicity (17.50-25.99 g/100 g) of obtained powders were evaluated. The stability of encapsulated anthocyanins, monitored through the total anthocyanin content, was evaluated with the pH differential method immediately after production and after a 10-week storage under different conditions of temperature (5 or 37 °C), humidity (45 or 85% RH), in presence or absence of light. The colour parameters (a, b*, L*, C*, H°, ΔE^*) of powders were measured. The results indicated that yeast-hulls showed a good ability to protect anthocyanin against the influence of temperature, light, moisture compared to freeze-dried anthocyanins-rich extracts (p < 0.05). Yeast hulls protected anthocyanin better than maltodextrin under high humidity conditions (p < 0.05).

Anthocyanins: Traditional Uses, Structural and Functional Variations, Approaches to Increase Yields and Products' Quality, Hepatoprotection, Liver Longevity, and Commercial Products

Anthocyanins are water-soluble, colored compounds of the flavonoid class, abundantly found in the fruits, leaves, roots, and other parts of the plants. The fruit berries are prime sources and exhibit different colors. The anthocyanins utility as traditional medicament for liver protection and cure, and importance as strongest plants-based anti-oxidants have conferred these plants products different biological activities. These activities include anti-inflammation, liver protective, analgesic, and anti-cancers, which have provided the anthocyanins an immense commercial value, and has impelled their chemistry, biological activity, isolation, and quality investigations as prime focus. Methods in extraction and production of anthocyanin-based products have assumed vital economic importance. Different extraction techniques in aquatic solvents mixtures, eutectic solvents, and other chemically reactive extractions including low acid concentrations-based extractions have been developed. The prophylactic and curative therapy roles of the anthocyanins, together with no reported toxicity has offered much-needed impetus and economic benefits to these classes of compounds which are commercially available. Information retrieval from various search engines, including the PubMed®, ScienceDirect®, Scopus®, and Google Scholar®, were used in the review preparation. This imparted an outlook on the anthocyanins occurrence, roles in plants, isolation-extraction, structures, biosynthetic as well as semi- and total-synthetic pathways, product quality and yields enhancements, including uses as part of traditional medicines, and uses in liver disorders, prophylactic and therapeutic applications in liver protection and longevity, liver cancer and hepatocellular carcinoma. The review also highlights the integrated approach to yields maximizations to meet the regular demands of the anthocyanins products, also as part of the extract-rich preparations together with a listing of marketed products available for human consumption as nutraceuticals/food supplements.

Effect of Hibiscus sabdariffa and Camellia synensis extracts on microbial, antioxidant and sensory properties of ice cream

Herbal extracts have been widely used by consumers for food fortification and medical purposes worldwide and are focused in traditional medicine in recent years. At this study, we aimed to examine the antimicrobial, antioxidant and sensory characteristics of ice creams fortified with different combinations of Hibiscus sabdariffa and Camellia synensis determined by Design of Experiments software. Levels of 10-100 and 40-400 mg/kg for Hibiscus sabdariffa and Camellia synensis extracts, respectively, were selected and experiments were conducted by central composite design. Generally, 13 runs were introduced by the software and followed in laboratory for analysis. Antimicrobial activity was studied against Escherichia coli and Staphylococcus aureus as indicators of gram negative and gram positive bacteria. Results showed that all combinations were active against both bacteria but Staphylococcus aureus was more sensitive than Escherichia coli. Importantly, Camellia synensis was more effective than Hibiscus sabdariffa in both antimicrobial and antioxidant experiments but sensory panelists selected the sample containing lowest concentrations of both extracts. However, frequent consumption of low-dose fortified dairies with Hibiscus sabdariffa and Camellia synensis could be helpful for consumers interested in functional foods.

Storage stability of freeze-dried powder of jambolan (Syzygium cumini (L.)) fruits at different degrees of maturity and packages

Abstract Powder from jambolan fruit is rich in bioactive compounds, such as pigments, and they present the potential to be used as a food colorant. This study aims to evaluate color and total anthocyanin content (TAC) and stability in freeze-dried powder of jambolan fruits at four different degrees of maturity during storage in low-density polyethylene (LDPE) and metalized films at room temperature, thus simulating the storage after opening the package. The powder of fully mature fruits showed the highest anthocyanin content, evidenced by its intense purple color, as well as the highest anthocyanin degradation rate during storage after opening the package. The metalized film showed an anthocyanin concentration loss of 44%, however, the loss was 56% for the LDPE film. Immature fruits became darker, whereas the matured ones kept stable lightness within 90 days. The hygroscopicity increased with maturation, being related to the stability of anthocyanins with storage time. The metalized packaging assured stronger color and anthocyanin protection, besides enabling lower moisture gain in jambolan powders than LDPE packaging.

Cranberry (Vaccinium macrocarpon) Juice Precipitate Pigmentation Is Mainly Polymeric Colors and Has Limited Impact on Soluble Anthocyanin Loss

Anthocyanins degrade in fruit juice during storage, reducing juice color quality and depleting the health-promoting components of juice. Common water-soluble products of anthocyanins' chemical degradation are known, but little is known about the contribution of the insoluble phase to loss processes. Cranberry juice and isolated anthocyanins were incubated at 50 °C for up to 10 days to determine polyphenol profiles and degradation rates. Anthocyanin-proanthocyanidin heteropolymers were analyzed via Matrix Assisted Laser Desorption/Ionization (MALDI)- Time of Flight (TOF) Mass Spectrometry (MS). Formation of soluble protocatechuic acid accounted for 260 ± 10% and insoluble materials for 80 ± 20% of lost soluble cyanidin-glycosides in juice, over-representations plausibly due to quercetin and (epi)catechin in cranberry juice and not observed in the values of 70 ± 20% and 16 ± 6% in the purified anthocyanin system. Loss processes of soluble peonidin-glycosides were better accounted for, where 31 ± 2% were attributable to soluble vanillic acid formation and 3 ± 1% to insoluble materials in cranberry juice and 35 ± 5% to vanillic acid formation and 1.6 ± 0.8% to insoluble materials in the purified anthocyanin system. Free anthocyanins were below quantifiable levels in precipitate, implying most anthocyanins in precipitate were polymeric colors (PCs). PCs in the precipitate included cyanidin- and peonidin-hexosides and -pentosides covalently bonded to procyanidins. Therefore, formation of cranberry juice precipitate does not deplete a large portion of soluble anthocyanins; rather, the precipitate's pigmentation results from PCs that are also present in the soluble phase.

Effect of High Hydrostatic Pressure Processing on the Anthocyanins Content, Antioxidant Activity, Sensorial Acceptance and Stability of Jussara (Euterpe edulis) Juice

Jussara (Euterpe edulis) fruit is a strong candidate for exportation due to its high content of anthocyanins. However, its rapid perishability impairs its potential for further economic exploration, highlighting the relevance of producing ready-to-drink juices by applying innovative processing, such as high hydrostatic pressure (HHP). The effect of HHP (200, 350, and 500 MPa for 5, 7.5, and 10 min) on anthocyanins content and antioxidant activity (AA) by FRAP and TEAC assays, and the most effective HHP condition on overall sensory acceptance and stability of jussara juice, were investigated. While mild pressurization (200 MPa for 5 min) retained anthocyanins and AA, 82% of anthocyanins content and 46% of TEAC values were lost at the most extreme pressurization condition (500 MPa for 10 min). The addition of 12.5% sucrose was the ideal for jussara juice consumer acceptance. No significant difference was observed for overall sensory acceptance scores of unprocessed (6.7) and HHP-processed juices (6.8), both juices being well-accepted. However, pressurization was ineffective in promoting the retention of anthocyanins and AA in jussara juice stored at refrigeration temperature for 60 days, probably due to enzymatic browning.

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

Anthocyanins are colored valuable biocompounds, of which extraction increases globally, although functional applications are restrained by their limited environmental stability. Temperature is a critical parameter of food industrial processing that impacts on the food matrix, particularly affecting heat-sensitive compounds such as anthocyanins. Due to the notable scientific progress in the field of thermal stability of anthocyanins, an analytical and synthetic integration of published data is required. This review focuses on the molecular mechanisms and the kinetic parameters of anthocyanin degradation during heating, both in extracts and real food matrices. Several kinetic models (Arrhenius, Eyring, Ball) of anthocyanin degradation were studied. Crude extracts deliver more thermally stable anthocyanins than purified ones. A different anthocyanin behavior pattern within real food products subjected to thermal processing has been observed due to interactions with some nutrients (proteins, polysaccharides). The most recent studies on the stabilization of anthocyanins by linkages to other molecules using classical and innovative methods are summarized. Ensuring appropriate thermal conditions for processing anthocyanin-rich food will allow a rational design for the future development of stable functional products, which retain these bioactive molecules and their functionalities to a great extent.

Effect of Freeze Drying and Simulated Gastrointestinal Digestion on Phenolic Metabolites and Antioxidant Property of the Natal Plum (Carissa macrocarpa)

Natal plums (Carissa macrocarpa) are a natural source of bioactive compounds, particularly anthocyanins, and can be consumed as a snack. This study characterized the impact of freeze drying and in vitro gastrointestinal digestion on the phenolic profile, antioxidant capacity, and α-glucosidase activity of the Natal plum (Carissa macrocarpa). The phenolic compounds were quantified using high performance liquid chromatography coupled to a diode-array detector HPLC-DAD and an ultra-performance liquid chromatograph (UPLC) with a Waters Acquity photodiode array detector (PDA) coupled to a Synapt G2 quadrupole time-of-flight (QTOF) mass spectrometer. Cyanidin-3-O-β-sambubioside (Cy-3-Sa) and cyanidin-3-O-glucoside (Cy-3-G) were the dominant anthocyanins in the fresh and freeze-dried Natal plum powder. Freeze drying did not affect the concentrations of both cyanidin compounds compared to the fresh fruit. Both cyanidin compounds, ellagic acid, catechin, epicatechin syringic acid, caffeic acid, luteolin, and quercetin O-glycoside from the ingested freeze-dried Natal plum powder was quite stable in the gastric phase compared to the small intestinal phase. Cyanidin-3-O-β-sambubioside from the ingested Natal plum powder showed bioaccessibility of 32.2% compared to cyanidin-3-O-glucoside (16.3%). The degradation of anthocyanins increased the bioaccessibility of gallic acid, protocatechuic acid, coumaric acid, and ferulic acid significantly, in the small intestinal digesta. The ferric reducing antioxidant power (FRAP), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) activities, and inhibitory effect of α-glucosidase activity decreased in the small intestinal phase. Indigenous fruits or freeze-dried powders with Cy-3-Sa can be a better source of anthocyanin than Cy-3-G due to higher bioaccessibility in the small intestinal phase.

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

Cherries are rich in bioactive phenolic compounds and are often fermented into cherry wines. The degradation of anthocyanins during storage will cause color deterioration. The study aimed to utilize sinapic acid and grape tannins in cherry wine to maintain a high fraction in the colored forms of anthocyanins, in order to maximize the color intensity, the latter being associated with good product quality. The effects on the anthocyanin profile and on color parameters of copigments, utilizing spectral measurement combined with UPLC-MS quantitative analysis, have been evaluated in sweet cherry wines. The copigmentation effect of sinapic acid and grape tannin was accompanied by the bathochromic shift and the hyperchromic effect, which lead to an increase in color intensity (lower L*, higher a* and b*). During the aging process, sinapic and grape tannin increased the content of pyranoanthocyanins in cherry wine, especially the addition of sinapic acid makes the cherry wine generate 10-syringyl-pyranocyanidin-3-rutinoside. These results demonstrate that sinapic acid is suitable for adding before alcohol fermentation, while grape tannins can be added before aging.

Interactions between caseins and food-derived bioactive molecules: A review

Caseins are recognized as safe for consumption, abundant, renewable and have high nutritional value. Casein molecules are found in different aggregation states and their multiple binding sites offer the potential for delivering biomolecules with nutritional and/or health benefits, such as vitamins, phytochemicals, fibers, lipids, minerals, proteins, peptides, and pharmaceutical compounds. In the present review, we highlight the interactions between caseins and food-derived bioactive molecules, with a special focus on the aggregation states of caseins and the techniques used to produce and study the particles used for delivering. Research on interactions between caseins-minerals and casein-pharmaceutical molecules are not included here. This review aims to support the development of new and innovative functional foods in which caseins can be used as designed delivery systems.