Promising Antioxidant and Antimicrobial Food Colourants from Lonicera caerulea L. var. Kamtschatica

Natural Sources of Food Colorants as Potential Substitutes for Artificial Additives

In recent years, the demand of healthier food products and products made with natural ingredients has increased overwhelmingly, led by the awareness of human beings of the influence of food on their health, as well as by the evidence of side effects generated by different ingredients such as some additives. This is the case for several artificial colorants, especially azo colorants, which have been related to the development of allergic reactions, attention deficit and hyperactivity disorder. All the above has focused the attention of researchers on obtaining colorants from natural sources that do not present a risk for consumption and, on the contrary, show biological activity. The most representative compounds that present colorant capacity found in nature are anthocyanins, anthraquinones, betalains, carotenoids and chlorophylls. Therefore, the present review summarizes research published in the last 15 years (2008-2023) in different databases (PubMed, Scopus, Web of Science and ScienceDirect) encompassing various natural sources of these colorant compounds, referring to their obtention, identification, some of the efforts made for improvements in their stability and their incorporation in different food matrices. In this way, this review evidences the promising path of development of natural colorants for the replacement of their artificial counterparts.

Wild sweet cherry, strawberry and bilberry as underestimated sources of natural colorants and bioactive compounds with functional properties

Wild edible fruits, neglected by the development of commercial agriculture, have recently aroused as a good source of natural colorants and bioactive compounds. These novel uses could cover the recent demand for healthier foods with functional properties. Prunus avium, Fragaria vesca and Vaccinium myrtillus wild fruits were characterized by individual anthocyanin profile and color CIELAB parameters, as well as phenolic fraction. In addition, some bioactivities were evaluated. In P. avium cyanidin-O-deoxyhexosyl-pentoside was the representative anthocyanin, in F. vesca pelargonidin-3-O-glucoside and in V. myrtillus delphinidin-O-hexoside. The three wild edible fruits showed interesting antioxidant activity especially in OxHLIA assays. V. myrtillus was the fruit with the best results for the bacterial growth inhibition, while F. vesca with better fungal growth inhibition. These results evidenced the richness of these wild fruits in bioactive compounds and pigments with antioxidant capacity, therefore, their potential use as natural colorants for healthier food products design.

Impact of the Addition of Fruits of Kamchatka Berries (L. caerulea var. kamtschatica) and Haskap (L. caerulea var. emphyllocalyx) on the Physicochemical Properties, Polyphenolic Content, Antioxidant Activity and Sensory Evaluation Craft Wheat Beers

Kamchatka berry (Lonicera caerulea var. kamtschatica) and haskap (Lonicera caerulea var. emphyllocalyx) fruit are important sources of bioactive compounds, mainly polyphenols, but also macro- and microelements. Physico-chemical analysis showed that wheat beers with added fruit were characterised by an average 14.06% higher ethanol content, lower bitterness and intense colour compared to the control, which was a wheat beer without added fruit. Wheat beers enriched with kamchatka berry fruit, including the "Aurora" variety, had the highest polyphenolic profile (e.g., chlorogenic acid content averaged 7.30 mg/L), and the antioxidant activity of fruit-enriched wheat beers determined by the DPPH method showed higher antioxidant activity of wheat beers enriched with kamchatka berry fruit, while those determined by the FRAP and ABTS methods showed higher antioxidant activity of wheat beers enriched with haskap fruit, including the "Willa" variety. Sensory evaluation of the beer product showed that wheat beers enriched with kamchatka berry fruits of the "Duet" variety and haskap fruits of the "Willa" variety were characterised by the most balanced taste and aroma. On the basis of the conducted research, it follows that both kamchatka berry fruits of the "Duet" and "Aurora" varieties and haskap fruit of the "Willa" variety can be used successfully in the production of fruity wheat beers.

Anthocyanins ameliorate obesity-associated metainflammation: Preclinical and clinical evidence

The growing rates of obesity worldwide call for intervention strategies to help control the pathophysiological consequences of weight gain. The use of natural foods and bioactive compounds has been suggested as such a strategy because of their recognized antioxidant and anti-inflammatory properties. For example, polyphenols, especially anthocyanins, are candidates for managing obesity and its related metabolic disorders. Obesity is well known for the presence of metainflammation, which has been labeled as an inflammatory activation that leads to a variety of metabolic disorders, usually related to increased oxidative stress. Considering this, anthocyanins may be promising natural compounds able to modulate several intracellular mechanisms, mitigating oxidative stress and metainflammation. A wide variety of foods and extracts rich in anthocyanins have become the focus of research in the field of obesity. Here, we bring together the current knowledge regarding the use of anthocyanins as an intervention tested in vitro, in vivo, and in clinical trials to modulate metainflammation. Most recent research applies a wide variety of extracts and natural sources of anthocyanins, in diverse experimental models, which represents a limitation of the research field. However, the literature is sufficiently consistent to establish that the in-depth molecular analysis of gut microbiota, insulin signaling, TLR4-triggered inflammation, and oxidative stress pathways reveals their modulation by anthocyanins. These targets are interconnected at the cellular level and interact with one another, leading to obesity-associated metainflammation. Thus, the positive findings with anthocyanins observed in preclinical models might directly relate to the positive outcomes in clinical studies. In summary and based on the entirety of the relevant literature, anthocyanins can mitigate obesity-related perturbations in gut microbiota, insulin resistance, oxidative stress and inflammation and therefore may contribute as a therapeutic tool in people living with obesity.

Bioactive Natural Pigments' Extraction, Isolation, and Stability in Food Applications

Color in food has multiple effects on consumers, since this parameter is related to the quality of a product, its freshness, and even its nutrient content. Each food has a characteristic color; however, this can be affected by the technological treatments that are applied during its manufacturing process, as well as its storage. Therefore, the development of new food products should take into account consumer preferences, the physical properties of a product, food safety standards, the economy, and applications of technology. With all of this, the use of food additives, such as dyes, is increasingly important due to the interest in the natural coloring of foods, strict regulatory pressure, problems with the toxicity of synthetic food colors, and the need for globally approved colors, in addition to current food market trends that focus on the consumption of healthy, organic, and natural products. It is for this reason that there is a growing demand for natural pigments that drives the food industry to seek or improve extraction techniques, as well as to study different stability processes, considering their interactions with the food matrix, in order to meet the needs and expectations of consumers.

Influence of Altitudes and Development Stages on the Chemical Composition, Antioxidant, and Antimicrobial Capacity of the Wild Andean Blueberry (Vaccinium floribundum Kunth)

The chemical composition and biological capacities of berries depend on environmental parameters, maturity, and location. The Andean blueberry (Vaccinium floribundum Kunth), also known as mortiño, presents a unique combination of several phytochemicals, which play a synergistic role in its characterization as a functional food. We aimed to expose the possible variations that exist in the profile of the phenolic compounds as well as the antioxidant and antimicrobial capacity of the wild Andean blueberry with respect to three ripeness stages and two different altitudes. We found that polyphenols are the predominant compounds in the berry during the early ripeness stage and are the main bioactive compounds that give rise to the antioxidant capacity and inhibition effect on the growth of gram-positive and gram-negative bacteria. Moreover, the accumulation of ascorbic acid, free amino acids, and anthocyanins increases as the ripening process progresses, and they were the main bioactive compounds in the ripe berry. The latter compounds influence the production of the typical bluish or reddish coloration of ripe blueberries. In addition, it was determined that environmental conditions at high altitudes could have a positive influence in all cases. Overall, our data provide evidence regarding the high functional value of the wild Andean blueberry.

Lonicera caerulea (Haskap berries): a review of development traceability, functional value, product development status, future opportunities, and challenges

Lonicera caerulea is a honeysuckle plant with a long development history. It is defined as a "homology of medicine and food" fruit because it is rich in bioactive substances. By-products (such as pomace, leaves, stems, and flowers), which also have beneficial values, will be produced during processing. Nevertheless, the reuse of derivatives and the further development of new products of Lonicera caerulea are still a challenge. Firstly, this paper traced the development history of Lonicera caerulea and summarized its primary nutrients and bioactive substances, subsequently discussed the research progress and underlying molecular mechanisms of its functional properties, and introduced the application and potential of Lonicera caerulea in the fields of food, health products, cosmetics, medicine, and materials. Finally, this paper put forward the future research direction to promote the development of the Lonicera caerulea industry. To sum up, Lonicera caerulea, as a potential raw material, can be used to produce more functional products. Besides, more in-depth clinical trials are needed to clarify the specific molecular mechanism of the practical components of Lonicera caerulea and improve the rate of development and utilization.HighlightsThe original species of Lonicera caerulea subgroup had appeared on the earth as early as the end of the third century.Lonicera caerulea has been introduced into North America since the 18th century, but the introduction process has not ended until now.Lonicera caerulea widely exists in Eurasia and North America and it has excellent cold tolerance, early maturity and ornamental.The fruits, stems, leaves and flowers of Lonicera caerulea all have bioactive value, but the specific molecular mechanism and utilization need to be improved.Lonicera caerulea has been widely used in food, medicine, health products, cosmetics and materials, but there are still great challenges.

Evaluation of Immunotropic Activity of Iridoid-Anthocyanin Extract of Honeysuckle Berries (Lonicera caerulea L.) in the Course of Experimental Trichinellosis in Mice

Our experiment determined the immunotropic activity of a natural, iridoid-anthocyanin extract from honeysuckle berry (Lonicera caerulea L.) (LC). The extract was administered to mice infected with Trichinella spiralis, orally at a dose of 2 g/kg bw, six times at 24 h intervals (from day 3 prior to the infection to day 3 post-infection (dpi) with T. spiralis. At 5, 7, 14, and 21 dpi, samples of blood, spleen, and mesenteric lymph nodes (MLN) were collected, and isolated lymphocytes were analyzed by flow cytometry. The splenocyte proliferation was estimated with MTT testing, and the intensity of intestinal and muscle infection was also studied. LC stimulated the local immune system by inducing lymphocyte proliferation in the spleen 7 dpi and altered the percentage and absolute count of B (CD19⁺) and T (CD3⁺, CD8⁺) cells 7, 14, and 21 dpi in the peripheral blood. LC extract affected the dynamics of expulsion of adult Trichinella from the intestines and prolonged the intestinal phase of the infection but did not change the number of larvae in the muscles. These results suggest that Lonicera caerulea L. fruit extract modulates murine cellular immune response during intestinal phase of T. spiralis infection but shows no antiparasitic activity.

Phenolic Compounds, Vitamins C and E and Antioxidant Activity of Edible Honeysuckle Berries (Lonicera caerulea L. var. kamtschatica Pojark) in Relation to Their Origin

Honeysuckles are frost tolerant plants providing early-ripening fruits with health-promoting properties which have been used in traditional medicine in China. This study evaluates the impact of the climatic conditions of two areas on the chemical composition and antioxidant activity (AOA; by DPPH-2,2-diphenyl-1-picrylhydrazyl and photochemiluminescence assays) of eight cultivars of honeysuckle berries (Lonicera caerulea L. var. kamtschatica Pojark) of various ripening times. Expectedly, chemical composition and AOA values varied depending on the cultivars, locality and selected methods. Berries from Lednice (the area with more sunshine) showed higher average contents of total monomeric anthocyanins (TMAC; pH differential absorbance method), vitamins C and E and total phenolics (high-performance liquid chromatography). In contrast, berries from Žabčice (the area with more rain) performed higher average contents of total phenolics and flavonoids (UV/VIS spectroscopic analyses). Interestingly, fundamental amounts of chlorogenic acid were determined irrespective of the locality. Regarding TMAC and vitamin C content, early ripening Amphora from both areas has been assessed as the best cultivar; concerning the content of phenolic compounds, Fialka from both areas and Amphora from Lednice is considered as the most valuable. The obtained results may facilitate the selection of the most valuable cultivars for both producers and consumers.

Honeysuckle extract (Lonicera pallasii L.) exerts antioxidant properties and extends the lifespan and healthspan of Drosophila melanogaster

Honeysuckle Lonicera pallasii (Lonicera caerulea L.) is an excellent source of anthocyanins which have a number of health-promoting properties mainly associated with antioxidant and anti-inflammatory activities. Cyanidin-3-O-glucoside (C3G) is one of the most common anthocyanins naturally found in honeysuckle. The goal of the present study was to investigate antioxidant and anti-aging properties of Lonicera pallasii (Lonicera caerulea L.) extract (LE) and C3G using red blood cells (RBC) and Drosophila melanogaster models. LE and C3G treatment at a concentration of 100 μM induced enhancement of median and maximum lifespan up to 8%. LE and C3G supplementation at a concentration of 100 μM increased stress resistance up to 10%. The locomotor activity decreased during LE and C3G treatment in 4 and 6 weeks up to 52% in females. The integrity of the intestinal barrier was increased by 4% after LE treatment. These effects were accompanied by increased expression of Hif1 (pro-longevity gene) in response to C3G treatment and decreased expression of Keap1 (anti-longevity gene) after C3G and LE supplementation. RNA interference-mediated knockdown of Sirt6 completely abolished the positive effect obtained of LE and C3G supplementation in males which indicates that lifespan-extending effect is associated with Sirt6 activation. The experiments on the various in-vitro models (including radical scavenging activity and oxidative hemolysis of RBC demonstrated antioxidant and membrane-protective activities of LE and C3G. The present study indicates that Lonicera extract can prolong the lifespan and improve the healthspan of Drosophila model through biological and antioxidant activities.

Anthocyanins from Rubus fruticosus L. and Morus nigra L. Applied as Food Colorants: A Natural Alternative

Given the importance of colour in the general acceptance or rejection of a product, the use of colorants is a widespread practice, particularly in the food industry. At the same time, with the increasing consumers' awareness of the health effects that some artificial colorants can exert, there is a growing tendency to prioritize foodstuffs containing natural additives. In this work, Morus nigra L. and Rubus fruticosus L. fruit juices were characterized in terms of anthocyanins, organic acids, free sugars, and tocopherols, as also regarding their bioactive properties. Given their richness in anthocyanins, this study also aimed to prepare different solid colouring formulations by the spray-drying technique, using as stabilizers maltodextrin and arabic gum. Six free sugars and two organic acids were detected in the fruit juices, as well as the four tocopherol isoforms. Two cyanidin derivatives were found in M. nigra (cyanidin-3-O-glucoside and cyanidin-O-rhamnoside) and other four in R. fruticosus (cyanidin-O-hexoside, cyanidin-3-O-glucoside, cyanidin-O-pentoside, and cyanidin-3-O-dioxaloilglucoside). The developed colouring formulations revealed a good stability over time, in terms of anthocyanin concentration and colour parameters, and revealed to be safe for consumption, either concerning their low microbial load and lack of cytotoxicity. Thus, they represent a promising natural alternative to the massively used artificial colorants.

Bioactive Compounds, Antioxidant, and Antibacterial Properties of Lonicera caerulea Berries: Evaluation of 11 Cultivars

The aim of the study was to evaluate 11 cultivars of blue honeysuckle (Lonicera caerulea L.) for bioactive compounds, antioxidant capacity, and the antibacterial activity of berries. Total phenolic contents (TPCs) and total anthocyanin contents (TACs) were established by using ethanolic extracts. For contents of organic acids and saccharides, aqueous extracts were used, and vitamin C was determined by using oxalic acid solution. DPPH^• radical scavenging capacity was evaluated by using ethanolic extracts; antibacterial activity was assessed by using both ethanolic and aqueous extracts. The TPC varied from 364.02 ± 0.41 mg/100 g in ‘Vostorg’ to 784.5 ± 0.3 mg/100 g in ‘Obilnaja’, and TAC ranged from 277.8 ± 1.1 mg/100 g in ‘Čelnočnaja’ to 394.1 ± 8.4 mg/100 g in ‘Nimfa’. Anthocyanins comprised 53.8% of total phenolic contents on average. Among organic acids, citric acid was predominant, averaging 769.41 ± 5.34 mg/100 g, with malic and quinic acids amounting to 289.90 ± 2.64 and 45.00 ± 0.37 mg/100 g on average, respectively. Contents of vitamin C were 34.26 ± 0.25 mg/100 g on average. Organic acids were most effective in the inhibition of both Gram-positive and Gram-negative bacteria tested. In conclusion, berries of L. caerulea are beneficial not only for fresh consumption, but also as a raw material or ingredients of foods with high health-promoting value.

Health benefits of cyanidin-3-glucoside as a potent modulator of Nrf2-mediated oxidative stress

Berries are natural sources of anthocyanins, especially cyanidin-3-glucoside (C3G), and exhibit significant antioxidant, antidiabetic, anti-inflammatory, and cytoprotective effects against various oxidative stress-induced disorders. C3G and its metabolites possess higher absorption and bioavailability, and interaction with gut microbiota may enhance their health benefits. Various in vitro studies have shown the reactive oxygen species (ROS)-mitigating potential of C3G. However, in in vivo models, C3G exerts its cytoprotective properties by regulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant-responsive element (ARE) pathway. Despite existing reports stating various health benefits of C3G, its antioxidant potential by modulating the Nrf2 pathway remains less identified. This review discusses the Nrf2-mediated antioxidant response of C3G in modulating oxidative stress against DNA damage, apoptosis, carcinogen toxicity, and inflammatory conditions. Furthermore, we have reviewed the recent clinical trial data to establish cross talk between a berry-rich diet and disease prevention.

Phenolic Profiles, Antioxidant Activity and Phenotypic Characterization of Lonicera caerulea L. Berries, Cultivated in Lithuania

Lonicera caerulea L. is an early fruit-bearing plant that originates from harsh environments. Raw materials contain a body of different phenolic origin compounds that determine the multidirectional antioxidant and pharmacological activities. The aim of this study was to comprehensively evaluate the phenolic composition, antioxidant capacities, vegetative, pomological, and sensory properties and their interrelations of selected L. caerulea cultivars, namely ‘Amphora’, ‘Wojtek’, ‘Iga’, ’Leningradskij Velikan’, ‘Nimfa’, ‘Indigo Gem’, ‘Tundra’, ‘Tola’, and fruit powders. Combined chromatographic systems were applied for the qualitative and quantitative profiling of 23 constituents belonging to the classes of anthocyanins, flavonols, flavones, proanthocyanidins, and phenolic acids. The determined markers of phytochemical profiles were cyanidin-3-glucoside, rutin, chlorogenic, and 3,5-dicaffeoylquinic acid. Anthocyanins and the predominant compound, cyanidin-3-glucoside, were the determinants of antioxidant activity. Cultivars ‘Amphora’, ‘Indigo Gem’, and ‘Tundra’ contained the greatest total amounts of identified phenolic compounds. Phenotypic characterization revealed the superiority of cultivars ‘Wojtek’ and ’Tundra’ compared to other cultivars, although ’Wojtek’ had low phenolic content and antioxidant activity and ’Tundra’ got lower sensory evaluation scores. Coupling the results of phenotypic and phytochemical characterization, cultivar ‘Tundra’ could be suitable for commercial plantations.

Evaluation of Anthocyanin Content, Antioxidant Potential and Antimicrobial Activity of Black, Purple and Blue Colored Wheat Flour and Wheat-Grass Juice against Common Human Pathogens

The present study aimed to analyze the antioxidant and antimicrobial activity of anthocyanins extracted from colored wheat flour and wheat-grass juice against human pathogens. The total anthocyanin content and antioxidant potential in colored wheat flour and wheat-grass juice extracts were significantly higher than white flour and wheat-grass juice extracts. Ultra-performance liquid chromatography showed the maximum number of anthocyanin peaks in black wheat, with delphinidin-3-o-galactoside chloride, delphinidin-3-o-glucoside chloride, and cyanindin-3-o-glucoside chloride as the major contributors. Among flour extracts, maximum zones of inhibition against Staphylococcus aureus (MTCC 1934), Pseudomonas aeruginosa (MTCC 1434), Escherichia coli, and Candida albicans (MTCC 227) were produced by black flour extract, having the highest anthocyanin content. It exhibited a minimum microbicidal concentration (MMC) of 200 mg/mL against E. coli and C. albicans; and 100 and 150 mg/mL against S. aureus and P. aeruginosa, respectively. Black and purple flour extracts exhibited a minimum inhibitory concentration (MIC) of 50 mg/mL against S. aureus and P. aeruginosa. White flour extracts did not show MMC against E. coli and C. albicans. Among wheat-grass juice extracts, black wheat-grass was most effective and showed an MIC of 100-150 mg/mL against all pathogens. It exhibited an MMC of 200 mg/mL against S. aureus and P. aeruginosa. Hence, anthocyanin-rich colored wheat could be of nutraceutical importance.

Phytochemical Characterization of Blue Honeysuckle in Relation to the Genotypic Diversity of Lonicera sp

The phytochemical characteristic analysis of a group of 30 haskap berry genotypes was carried out bearing in mind the concern for the consumption of food with high nutraceutical value that helps maintain good health. Phytochemical fruit composition and antioxidant activity were assessed by the Folin–Ciocalteau, spectrophotometric, DPPH (1,1-diphenyl-2-picrylhydrazyl) as well as ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) method. Evaluation of antioxidant activity was referred to as the Trolox equivalent. The observed differences in the content of phenolics, flavonoids, vitamin C and antioxidant activity allowed us to select genotypes which, due to the high level of the analyzed compounds, are particularly recommended in everyone’s diet. In addition, the analysis of the prospects of increasing the analyzed phytochemical properties, estimated by parameters such as heritability and genetic progress, indicates the effectiveness of breeding in relation to each of the analyzed traits. The results of the presented research can be used in the implementation of future breeding programs for this valuable species.

Betacyanins from Gomphrena globosa L. flowers: Incorporation in cookies as natural colouring agents

A betacyanin rich extract was obtained from the flowers of Gomphrena globosa L. by ultrasound-assisted extraction and dried either by lyophilization or spray-drying, was tested as a natural colourant in cookies and compared to a commercial colourant. The extracts were characterized in terms of betacyanin content and antioxidant potential. The effects of the colourants incorporation in the cookies were assessed through proximate composition, soluble sugars, fatty acids, color, texture and microbial load, over a shelf life of 30 days. Considering all the assays and analyzing the results through a 2-way analysis of variance, the cookies incorporated with spray-dried colourant showed the most intense pink coloration while cookies incorporated with lyophilized extract lost less color intensity over time. Thus, betacyanin extracts have potential as pink natural alternatives to synthetic colourants in the food industry.

The Effect of the Addition of Blue Honeysuckle Berry Juice to Apple Juice on the Selected Quality Characteristics, Anthocyanin Stability, and Antioxidant Properties

Apple juice is rich in phenolic compounds that are important as natural antioxidants. In turn, blue honeysuckle berry juice is a valuable source of bioactive ingredients and can be an interesting and beneficial supplement to fruit juices. The aim of this study was to examine the physicochemical and sensory properties of the newly designed mixture of apple juice and blue honeysuckle berry juice. The addition of blue honeysuckle berry juice to apple juice had a significant effect on the content of anthocyanin and vitamin C in the newly designed fruit juices. After production, the content of anthocyanins and polyphenols in the blue honeysuckle berry juice was high (595.39 and 767.88 mg/100 mL, respectively). As the concentration of blue honeysuckle berry juice added to apple juice was increased, the polyphenol content also increased. The juices analyzed after 4 months of storage were lighter and showed a less intense red color than the juices analyzed directly after production. Antioxidant activity (ABTS assay) in the apple juice mixed with 10% blueberry juice was almost 3 times higher than the pure apple juice after 3 months of storage; the addition of 30% blueberry juice significantly increased the antioxidant activity of the apple juice. Thus, the results of this research have expanded the existing knowledge about the health and sensory properties of apple juice mixed with blue honeysuckle berry juice. These findings can be utilized in further research aiming at the development of new products that can meet consumer expectations.