effect of dose size on bioavailability of acylated and nonacylated anthocyanins from red cabbage (Brassica oleracea L. Var. capitata)

Bioavailability of Anthocyanins: Whole Foods versus Extracts

Anthocyanins have gained significant popularity in recent years for their diverse health benefits, yet their limited bioavailability poses a challenge. To address this concern, technologies have emerged to enhance anthocyanin concentration, often isolating these compounds from other food constituents. However, the extent to which isolated anthocyanins confer health benefits compared to their whole-food counterparts remains unclear. This review explores the current literature on anthocyanin bioavailability and metabolism in the body, with a focus on comparing bioavailability when consumed as extracts versus whole foods rich in anthocyanins, drawing from in vitro, in vivo, and human clinical studies. While direct comparisons between anthocyanin bioavailability in whole foods versus isolates are scarce, prevailing evidence favours whole-food consumption over anthocyanin extracts. Further clinical investigations, preferably with direct comparisons, are needed to validate these findings and elucidate the nuanced interplay between anthocyanins and food matrices, informing future research directions and practical recommendations.

Integrated metabolome and transcriptome analyses reveal the role of BoGSTF12 in anthocyanin accumulation in Chinese kale (Brassica oleracea var. alboglabra)

BACKGROUND

The vivid red, purple, and blue hues that are observed in a variety of plant fruits, flowers, and leaves are produced by anthocyanins, which are naturally occurring pigments produced by a series of biochemical processes occurring inside the plant cells. The purple-stalked Chinese kale, a popular vegetable that contains anthocyanins, has many health benefits but needs to be investigated further to identify the genes involved in the anthocyanin biosynthesis and translocation in this vegetable.

RESULTS

In this study, the purple- and green-stalked Chinese kale were examined using integrative transcriptome and metabolome analyses. The content of anthocyanins such as cyanidin-3-O-(6″-O-feruloyl) sophoroside-5-O-glucoside, cyanidin-3,5-O-diglucoside (cyanin), and cyanidin-3-O-(6″-O-p-hydroxybenzoyl) sophoroside-5-O-glucoside were considerably higher in purple-stalked Chinese kale than in its green-stalked relative. RNA-seq analysis indicated that 23 important anthocyanin biosynthesis genes, including 3 PAL, 2 C4H, 3 4CL, 3 CHS, 1 CHI, 1 F3H, 2 FLS, 2 F3'H, 1 DFR, 3 ANS, and 2 UFGT, along with the transcription factor BoMYB114, were significantly differentially expressed between the purple- and green-stalked varieties. Results of analyzing the expression levels of 11 genes involved in anthocyanin production using qRT-PCR further supported our findings. Association analysis between genes and metabolites revealed a strong correlation between BoGSTF12 and anthocyanin. We overexpressed BoGSTF12 in Arabidopsis thaliana tt19, an anthocyanin transport mutant, and this rescued the anthocyanin-loss phenotype in the stem and rosette leaves, indicating BoGSTF12 encodes an anthocyanin transporter that affects the accumulation of anthocyanins.

CONCLUSION

This work represents a key step forward in our understanding of the molecular processes underlying anthocyanin production in Chinese kale. Our comprehensive metabolomic and transcriptome analyses provide important insights into the regulatory system that controls anthocyanin production and transport, while providing a foundation for further research to elucidate the physiological importance of the metabolites found in this nutritionally significant vegetable.

Comparing the Chemistry of Malvidin-3-O-glucoside and Malvidin-3,5-O-diglucoside Networks: A Holistic Approach to the Acidic and Basic Paradigms with Implications in Biological Studies

The kinetics, thermodynamics, and degradation of malvidin mono- and diglucosides were studied following a holistic approach by extending to the basic medium. In acidic conditions, the reversible kinetics of the flavylium cation toward the equilibrium is controlled by the hydration and cis-trans isomerization steps, while in the basic medium, the OH- nucleophilic addition to the anionic quinoidal bases is the slowest step. There is a pH range (transition pHs), between the acidic and basic paradigms, that includes physiological pH (7.4), where degradation reactions occur faster, preventing the system from reaching the equilibrium. The transition pH of the diglucoside is narrower, and in contrast with the monoglucoside, there is no evidence for the formation of colored oligomers among the degradation products. Noteworthy, OH- addition in position 4 to form B42-, a kinetic product that decreases the overall equilibration rate, was observed only for the diglucoside.

Unlocking the health potential of anthocyanins: a structural insight into their varied biological effects

Anthocyanins have become increasingly important to the food industry due to their colorant features and many health-promoting activities. Numerous studies have linked anthocyanins to antioxidant, anti-inflammatory, anticarcinogenic properties, as well as protection against heart disease, certain types of cancer, and a reduced risk of diabetes and cognitive disorders. Anthocyanins from various foods may exhibit distinct biological and health-promoting activities owing to their structural diversity. In this review, we have collected and tabulated the key information from various recent published studies focusing on investigating the chemical structure effect of anthocyanins on their stability, antioxidant activities, in vivo fate, and changes in the gut microbiome. This information should be valuable in comprehending the connection between the molecular structure and biological function of anthocyanins, with the potential to enhance their application as both colorants and functional compounds in the food industry.

Fructo-oligosaccharide enhanced bioavailability of polyglycosylated anthocyanins from red radish via regulating gut microbiota in mice

The anthocyanins from red radish (ARR) rich in polyglycosylated pelargonidin glucosides were used as pigment. However, bioavailability of anthocyanins was considered at low level. This work examined the intensive effects of fructo-oligosaccharide (FOS) on ARR bioavailability. Pelargonidin, cyanidin and pelargonidin-3-glucoside showed higher level in serum of mice fed with FOS together with ARR for 8 weeks than that fed with only ARR. Co-ingestion of FOS and ARR more effectively elevated the hepatic antioxidant activity by increase in total antioxidant capacity and activities of superoxide dismutase and glutathione peroxidase when compared with intake of ARR. FOS also markedly increased pelargonidin level in cecum of mice. 16S RNA sequencing found that Bacteroides genus play an important role in FOS elevating bioavailability of ARR. Fecal bacteria transplantation verified the positive effects of FOS on ARR bioavailability. These results suggested that combined ingestion of FOS and ARR is effective strategy for bioactivity of ARR.

Structural Analysis and Identity Confirmation of Anthocyanins in Brassica oleracea Extracts by Direct Injection Ion Mobility-Mass Spectrometry

Anthocyanins are a subclass of plant-derived flavonoids that demonstrate immense structural heterogeneity which is challenging to capture in complex extracts by traditional liquid chromatography-mass spectrometry (MS)-based approaches. Here, we investigate direct injection ion mobility-MS as a rapid analytical tool to characterize anthocyanin structural features in red cabbage (Brassica oleracea) extracts. Within a 1.5 min sample run time, we observe localization of structurally similar anthocyanins and their isobars into discrete drift time regions based upon their degree of chemical modifications. Furthermore, drift time-aligned fragmentation enables simultaneous collection of MS, MS/MS, and collisional cross-section data for individual anthocyanin species down to a low picomole scale to generate structural identifiers for rapid identity confirmation. We finally identify anthocyanins in three other Brassica oleracea extracts based on red cabbage anthocyanin identifiers to demonstrate our high-throughput approach. Direct injection ion mobility-MS therefore provides wholistic structural information on structurally similar, and even isobaric, anthocyanins in complex plant extracts, which can inform the nutritional value of a plant and bolster drug discovery pipelines.

Crop, Host, and Gut Microbiome Variation Influence Precision Nutrition: An Example of Blueberries

Epidemiological studies have shown associations between polyphenol-rich fruit intake and bone health, and preclinical studies have shown that blueberries improve bone health. To determine the genotype and dose of blueberries that are effective in ameliorating age-related bone loss, a multi-institutional team of investigators performed in vitro, preclinical, and clinical studies on blueberry varieties that differed in flavonoid profiles. Principal component analysis was used to select blueberry genotypes that varied in anthocyanin profiles. Total phenolic content did not predict the bioavailability of polyphenolic compounds in rats. A range in bioavailability was observed in individual polyphenolic compounds across genotypes. Both alpha and beta diversity analyses indicated that gut microbiome profiles varied with blueberry dose in rats. Additionally, the identification of specific taxa, such as Prevotellaceae_UCG-001 and Coriobacteriales, increasing after blueberry consumption adds to the mounting evidence of their role in polyphenol metabolism. All of the sources of variation can inform blueberry breeding practices to influence precision nutrition.

Characterization of Purple Carrot Germplasm for Antioxidant Capacity and Root Concentration of Anthocyanins, Phenolics, and Carotenoids

The present study characterized a genetically and phenotypically diverse collection of 27 purple and two non-purple (one orange and one yellow) carrot accessions for concentration of root anthocyanins, phenolics, and carotenoids, and antioxidant capacity estimated by four different methods (ORAC, DPPH, ABTS, FRAP), in a partially replicated experimental design comprising data from two growing seasons (2018 and 2019). Broad and significant (p < 0.0001) variation was found among the accessions for all the traits. Acylated anthocyanins (AA) predominated over non-acylated anthocyanins (NAA) in all the accessions and years analyzed, with AA accounting for 55.5-100% of the total anthocyanin content (TAC). Anthocyanins acylated with ferulic acid and coumaric acid were the most abundant carrot anthocyanins. In general, black or solid purple carrots had the greatest TAC and total phenolic content (TPC), and the strongest antioxidant capacities, measured by all methods. Antioxidant capacity, estimated by all methods, was significantly, positively, and moderately-to-strongly correlated with the content of all individual anthocyanins pigments, TAC, and TPC, in both years (r = 0.59-0.90, p < 0.0001), but not with the carotenoid pigments lutein and β-carotene; suggesting that anthocyanins and other phenolics, but not carotenoids, are major contributors of the antioxidant capacity in purple carrots. We identified accessions with high concentration of chemically stable AA, with potential value for the production of food dyes, and accessions with relatively high content of bioavailable NAA that can be selected for increased nutraceutical value (e.g., for fresh consumption).

Phenolic features and anthocyanin profiles in winemaking pomace and fresh berries of grapes with different pedigrees

The total contents and antioxidant activities of phenolic compounds as well as anthocyanin profiles were analyzed and compared in fresh berries and fermented pomace of three grape cultivars with different pedigrees. The phenolic contents and antioxidant activities decreased significantly in skins (p < 0.05), while relatively large amounts of them were retained in seeds after fermentative maceration. Fermentative maceration also had a significant impact on the anthocyanin compositions. The proportions of anthocyanins with more stable structures, such as malvidin derivatives, methylated, diglucosides and nonacylated anthocyanins, increased significantly in the pomace skins (p < 0.05). There were obvious differences in phenolic features and anthocyanin profiles among the three cultivars. 'NW196', a wine hybrid of Vitis vinifera and V. quinquangularis, was characterized by the highest total anthocyanin contents and degree of diglucosylation. The results obtained in this study could contribute to the primary data for the development and utilization of winemaking pomace, especially from local non-Vitis vinifera grapes.

Flavonoids in vegetables: improvement of dietary flavonoids by metabolic engineering to promote health

Flavonoids are the most abundant polyphenols in plants, and have antioxidant effects as well as other bioactivities (e.g., anti-inflammatory, anti-cancer, anti-allergic, and neuroprotective effects). Vegetables are rich in flavonoids and are indispensable in our daily diet. Moreover, the vegetables as chassis for producing natural products would emerge as a promising means for cost-effective and sustainable production of flavonoids. Understanding the metabolic engineering of flavonoids in vegetables allows us to improve their nutrient composition. In this review, a comprehensive overview of flavonoids in vegetables, including the characterized types and distribution, health-promoting effects, associated metabolic pathways, and applied metabolic engineering are provided. We also introduce breakthroughs in multi-omics approaches that pertain to the elucidation of flavonoids metabolism in vegetables, as well as prospective and potential genome-editing technologies. Based on the varied composition and content of flavonoids among vegetables, dietary suggestions are further provided for human health.

Unveiling Natural and Semisynthetic Acylated Flavonoids: Chemistry and Biological Actions in the Context of Molecular Docking

Acylated flavonoids are widely distributed natural metabolites in medicinal plants and foods with several health attributes. A large diversity of chemical structures of acylated flavonoids with interesting biological effects was reported from several plant species. Of these, 123 compounds with potential antimicrobial, antiparasitic, anti-inflammatory, anti-nociceptive, analgesic, and anti-complementary effects were selected from several databases including SCI-Finder, Scopus, Google Scholar, Science Direct, PubMed, and others. Some selected reported biologically active flavonoids were docked in the active binding sites of some natural enzymes, namely acetylcholinesterase, butyrylcholinesterase, α-amylase, α-glucosidase, aldose reductase, and HIV integrase, in an attempt to underline the key interactions that might be responsible for their biological activities.

Dietary polyglycosylated anthocyanins, the smart option? A comprehensive review on their health benefits and technological applications

Over the years, anthocyanins have emerged as one of the most enthralling groups of natural phenolic compounds and more than 700 distinct structures have already been identified, illustrating the exceptional variety spread in nature. The interest raised around anthocyanins goes way beyond their visually appealing colors and their acknowledged structural and biological properties have fueled intensive research toward their application in different contexts. However, the high susceptibility of monoglycosylated anthocyanins to degradation under certain external conditions might compromise their application. In that regard, polyglycosylated anthocyanins (PGA) might offer an alternative to overcome this issue, owing to their peculiar structure and consequent less predisposition to degradation. The most recent scientific and technological findings concerning PGA and their food sources are thoroughly described and discussed in this comprehensive review. Different issues, including their physical-chemical characteristics, consumption, bioavailability, and biological relevance in the context of different pathologies, are covered in detail, along with the most relevant prospective technological applications. Due to their complex structure and acyl groups, most of the PGA exhibit an overall higher stability than the monoglycosylated ones. Their versatility allows them to act in a wide range of pathologies, either by acting directly in molecular pathways or by modulating the disease environment attributing an added value to their food sources. Their recent usage for technological applications has also been particularly successful in different industry fields including food and smart packaging or in solar energy production systems. Altogether, this review aims to put into perspective the current state and future research on PGA and their food sources.

Transcriptome and Metabolome Profiling to Explore the Causes of Purple Leaves Formation in Non-Heading Chinese Cabbage (Brassica rapa L. ssp. chinensis Makino var. mutliceps Hort.)

Purple non-heading Chinese cabbage is one of the most popular vegetables, and is rich in various health-beneficial anthocyanins. Research related to genes associated with anthocyanin biosynthesis in non-heading Chinese cabbage is important. This study performed integrative transcriptome and metabolome analysis in the purple non-heading Chinese cabbage wild type (WT) and its green mutant to elucidate the formation of purple leaves. The anthocyanin level was higher in purple than in green plants, while the contents of chlorophyll and carotenoid were higher in the green mutant than in the purple WT. Twenty-five anthocyanins were identified in purple and green cultivars; eleven anthocyanin metabolites were identified specifically in the purple plants. RNA-seq analysis indicated that 27 anthocyanin biosynthetic genes and 83 transcription factors were significantly differentially expressed between the WT and its mutant, most of them with higher expression in the purple than green non-heading Chinese cabbage. Transcriptome and metabolome analyses showed that UGT75C1 catalyzing the formation of pelargonidin-3,5-O-diglucoside and cyanidin-3,5-O-diglucoside may play a critical role in purple leaf formation in non-heading Chinese cabbage. Therefore, these results provide crucial information for elucidating the formation of purple leaves in non-heading Chinese cabbage.

Chemical Compounds of Berry-Derived Polyphenols and Their Effects on Gut Microbiota, Inflammation, and Cancer

Berry-derived polyphenols are bioactive compounds synthesized and secreted by several berry fruits. These polyphenols feature a diversity of chemical compounds, including phenolic acids and flavonoids. Here, we report the beneficial health effects of berry-derived polyphenols and their therapeutical application on gut-microbiota-related diseases, including inflammation and cancer. Pharmacokinetic investigations have confirmed the absorption, availability, and metabolism of berry-derived polyphenols. In vitro and in vivo tests, as well as clinical trials, showed that berry-derived polyphenols can positively modulate the gut microbiota, inhibiting inflammation and cancer development. Indeed, these compounds inhibit the growth of pathogenic bacteria and also promote beneficial bacteria. Moreover, berry-derived polyphenols exhibit therapeutic effects against different gut-microbiota-related disorders such as inflammation, cancer, and metabolic disorders. Moreover, these polyphenols can manage the inflammation via various mechanisms, in particular the inhibition of the transcriptional factor Nf-κB. Berry-derived polyphenols have also shown remarkable effects on different types of cancer, including colorectal, breast, esophageal, and prostate cancer. Moreover, certain metabolic disorders such as diabetes and atherosclerosis were also managed by berry-derived polyphenols through different mechanisms. These data showed that polyphenols from berries are a promising source of bioactive compounds capable of modulating the intestinal microbiota, and therefore managing cancer and associated metabolic diseases. However, further investigations should be carried out to determine the mechanisms of action of berry-derived polyphenol bioactive compounds to validate their safety and examinate their clinical uses.

Current Knowledge on Intestinal Absorption of Anthocyanins

Anthocyanins are flavonoid compounds that are natural color pigments occurring in various colored plants, such as berry fruits, vegetables, and grapes. With the elucidation of their various physiological effects, anthocyanins have been identified as promising functional food ingredients. However, findings on the bioavailability of anthocyanins, which are present in various chemical structures in foods, are limited; their intestinal absorption behaviors, including their transport route(s), have not been fully explained. This perspective overviews the current knowledge and issues and discusses advanced techniques, such as in situ matrix-assisted laser desorption/ionization mass spectrometry imaging, and future perspectives on the study of the bioavailability of anthocyanins.

Evaluation Study on Extraction of Anthocyanins from Red Cabbage Using High Pressure CO2 + H2O: A Fuzzy Logic Model and Metabolomic Analysis

In this work, a fuzzy logic model was developed to elucidate the extraction performance of high-pressure CO2 + H2O compared with traditional H2O extraction and aqueous ethanol extraction. The high-pressure CO2 + H2O group acquired the highest comprehensive score considering yield, quality and stability. Both targeted and untargeted metabolomics results proved that the polarity of water was slightly modified; in particular, with the evidence from the untargeted metabolomics data, a higher proportion of water-insoluble compounds (2-methylindole, 3-formylindole, guanine, tyrosine and tryptophan) obtained by high-pressure CO2 + H2O extraction compared with traditional H2O extraction has been reported for the first time. Finally, the “3I” extraction mechanism of high-pressure CO2 + H2O is proposed, which offers an improvement in the solid–liquid mass transfer efficiency of phytochemicals, improving the polarity of solution and the isolation of O2.

High-Resolution UPLC-MS Profiling of Anthocyanins and Flavonols of Red Cabbage (Brassica oleracea L. var. capitata f. rubra DC.) Cultivated in Egypt and Evaluation of Their Biological Activity

In this paper, biological investigations and a high-resolution UPLC-PDA-ESI-qTOF-HRMS technique were employed for Brassica oleracea L. var. capitata f. rubra DC. (red cabbage) of the family Brassicaceae (Cruciferae), cultivated in Egypt, for the first time. The positive ionization mode is usually performed to identify anthocyanins. However, this technique cannot differentiate between anthocyanins and corresponding non-anthocyanin polyphenols. Thus, the negative ionization mode was also used, as it provided a series of characteristic ions for the MS analysis of anthocyanins. This helped in identifying five kaempferol derivatives for the first time in red cabbage, as well as nine—previously reported—anthocyanins. For the biological investigations, the acidified methanolic extract of fresh leaves and the methanolic extract of air-dried powdered leaves were examined for their antioxidant, antimicrobial, and anticancer activities. The freshly prepared phenolic extract was proven to be more biologically potent. Statistical significance was determined for its anticancer activity in comparison with standard doxorubicin.

In vitro digestion, absorption and biological activities of acylated anthocyanins from purple sweet potatoes (Ipomoea batatas)

Purple sweet potatoes (PSP) are widely used as color enhancers in food formulations. Investigations on the stability of PSP polyphenolics during simulated digestion and subsequent absorption in a Caco-2 cell monolayer model were accomplished. Measures of bioactive activities were also assessed in vitro. PSP whole polyphenolic extracts as a control (WC) were compared to isolates enriched in anthocyanins (AC) or non-anthocyanin phenolics (NAP). Anthocyanins were also alkali-hydrolyzed to remove acylated moieties. Compounds were subjected to simulated gastro-intestinal digestions where non-hydrolyzed anthocyanins showed higher stability compared to alkali-hydrolyzed. For many alkali-hydrolyzed anthocyanins, the transport through a Caco-2 cell monolayer was reduced. PSP fractions significantly increased the generation of reactive oxygen species in HT-29 cells and was suppressive in the CCD-18Co cells while down-regulated mRNA expression of inflammatory markers. Results indicate the importance of PSP composition and the effects of acyl moieties on anthocyanin stability and functional properties for food colors.

Acylated anthocyanins: A review on their bioavailability and effects on postprandial carbohydrate metabolism and inflammation

Anthocyanins, the natural red and purple colorants of berries, fruits, vegetables, and tubers, improve carbohydrate metabolism and decrease the risk factors of metabolic disorders, but their industrial use is limited by their chemical instability. Acylation of the glycosyl moieties of anthocyanins, however, changes the chemical properties of anthocyanins and provides enhanced stability. Thus, acylated anthocyanins are more usable as natural colorants and bioactive components of innovative functional foods. Acylated anthocyanins are common in pigmented vegetables and tubers, the consumption of which has the potential to increase the intake of health-promoting anthocyanins as part of the daily diet. For the first time, this review presents the current findings on bioavailability, absorption, metabolism, and health effects of acylated anthocyanins with comparison to more extensively investigated nonacylated anthocyanins. The structural differences between nonacylated and acylated anthocyanins lead to enhanced color stability, altered absorption, bioavailability, in vivo stability, and colonic degradation. The impact of phenolic metabolites and their potential health effects regardless of the low bioavailability of the parent anthocyanins as such is discussed. Here, purple-fleshed potatoes are presented as a globally available, eco-friendly model food rich in acylated anthocyanins, which further highlights the industrial possibilities and nutritional relevance of acylated anthocyanins. This work supports the academic community and industry in food research and development by reviewing the current literature and highlighting gaps of knowledge.

Edible Plant Sprouts: Health Benefits, Trends, and Opportunities for Novel Exploration

The consumption of plant sprouts as part of human day-to-day diets is gradually increasing, and their health benefit is attracting interest across multiple disciplines. The purpose of this review was to (a) critically evaluate the phytochemicals in selected sprouts (alfalfa, buckwheat, broccoli, and red cabbage), (b) describe the health benefits of sprouts, (c) assess the recent advances in sprout production, (d) rigorously evaluate their safety, and (e) suggest directions that merit special consideration for further novel research on sprouts. Young shoots are characterized by high levels of health-benefitting phytochemicals. Their utility as functional ingredients have been extensively described. Tremendous advances in the production and safety of sprouts have been made over the recent past and numerous reports have appeared in mainstream scientific journals describing their nutritional and medicinal properties. However, subjects such as application of sprouted seed flours in processed products, utilizing sprouts as leads in the synthesis of nanoparticles, and assessing the dynamics of a relationship between sprouts and gut health require special attention for future clinical exploration. Sprouting is an effective strategy allowing manipulation of phytochemicals in seeds to improve their health benefits.

Red cabbage anthocyanins: Stability, extraction, biological activities and applications in food systems

Red cabbage anthocyanins are of great interest as natural food colorants in the food industry; as they represent the color over a broad range of pH-values compared to anthocyanins from other natural sources. It is important to select an appropriate technique with high recovery of anthocyanins from red cabbage, among which extraction with organic solvents is the most applied extraction method. Currently, novel extraction techniques are employed as an alternative to the solvent extraction method, providing advantages such as higher anthocyanin recovery in a shorter time, lower solvent utilization, and minimum quality degradation. However, the incorporation of extracted anthocyanins into foodstuffs and pharmacological products is limited due to their low bioavailability and relative instability toward environmental adverse conditions, such as pH, temperature, enzymes, light, oxygen and ascorbic acid. In addition to increased structural stability of anthocyanins through glycosylation and acylation, their stability could be improved by copigmentation and encapsulation.

Preparation and characterization of smart therapeutic pH-sensitive wound dressing from red cabbage extract and chitosan hydrogel

Developing a multifunctional wound dressing that protects, cures and indicates the healing progress, is a new approach of investigation. Red cabbage extract (RCE), consisting of bioactive compounds that have antioxidant, anti-inflammatory, anti-carcinogenic, bactericidal, antifungal, and antiviral activities, was utilized as a natural pH-sensitive indicator. Chitosan-based hydrogel, encapsulating RCE, was developed to obtain a smart therapeutic pH-sensitive wound dressing as antimicrobial bio-matrix provides a comfortable cushion for wound bed and indicates its status. Methacrylated-chitosan was crosslinked by different concentrations of methylenebisacrylamide (MBAA) by which hydrogel mechanical and morphological properties were tuned. The proposed mechanism for hydrogel formation was confirmed by FT-IR. The coloristic properties of the RCE and the changes in color intensity as a function of pH were confirmed by UV-Vis spectroscopy. The effect of MBAA on the mechanical, swelling, release and morphological properties of hydrogel were investigated. MBAA (2.5% wt/v) in 2% wt/v chitosan showed preferable mechanical (20 KPa), swelling (1294% at pH 8 ± 0.2), and release (prolonged up to 5 days) properties. Hydrogel matrices, loaded on cotton gauze submerged in different pH buffer solutions, showed explicit color changes from green to red as pH changed from 9 to 4.

Phenolic Metabolites in the Urine and Plasma of Healthy Men After Acute Intake of Purple Potato Extract Rich in Methoxysubstituted Monoacylated Anthocyanins

SCOPE

Structurally stable acylated anthocyanins have potential in various food applications but the effects of acylation and methoxysubstitution on anthocyanin metabolism are poorly understood. This is the first study thoroughly investigating phenolic metabolites, their time-wise changes, and pharmacokinetics following an acute intake of methoxysubstituted monoacylated anthocyanins.

METHODS AND RESULTS

Healthy male volunteers (n = 17) consumed a yellow potato meal with and without purple potato extract rich in acylated anthocyanins (152 mg) and hydroxycinnamic acid conjugates (140 mg). Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is used for identification and quantification of metabolites from serially collected urine and plasma. While the parent anthocyanins are not detected, 28 phenolic metabolites from urine and 14 from plasma are quantified, including hydroxybenzoic and hydroxycinnamic acids and protocatechuic acid sulfates and glucuronides; three (catechol, gallic acid-4-O-glucuronide, and 2-methoxybenzoic acid) are detected for the first time after anthocyanin-rich food. Urinary hippuric acid is the most abundant with an increase of 139 µM mM^-1 creatinine after the treatment. A large additional set of tentatively identified phenolic metabolites are detected. Late urinary peak time values suggest colonic degradation.

CONCLUSION

Acylated anthocyanins are more bioavailable than earlier reported after extensive degradation in human and/or colonial metabolism to phenolic metabolites, which may be further conjugated and demethylated.

Investigation on spontaneous 4D changes in color and flavor of healthy 3D printed food materials over time in response to external or internal pH stimulus

This study aimed to investigate 4D changes in colors and flavors of 3D-printed healthy food products in response to an external or internal pH stimulus. The formulations obtained by 3D printing of multi-smart materials, comprised of the combination of red cabbage juice, vanillin powder, potato starch and different fruit juices were used. 3D printing ability of red cabbage juice and vanillin powder affected by different potato starch concentrations was first studied. Then, changes in color, texture, flavor (by E-nose) and taste (by E-tongue) induced by the stimulus were determined. Results revealed that the color of the 3D-printed product changed from blue (control sample) to red, purple, violet, blue, blue-green, and green-yellow colors when sprayed with pH solutions of 2, 3-4, 5-6, 7, 8-9, and 10, respectively. In addition, clear differences in aroma and taste profiles among pH samples were detected. Moreover, dried 4D product samples exhibited color and anthocyanins stability when stored in ambient temperature for three weeks. This study is important for manufacturing new healthy 3D-printed food products with desired and attractive sensory characteristics, which can be particularly significant to people with poor appetite.

Chokeberry anthocyanins and their metabolites ability to cross the blood-cerebrospinal fluid barrier

The aim of this study was to determine whether anthocyanins and their phase II metabolites permeate the blood-cerebrospinal fluid barrier (B-CSF-B) of sheep and to profile these compounds in sheep biofluids after chokeberry intraruminal administration. Anthocyanins were analyzed using micro-HPLC-MS/MS. After chokeberry administration, anthocyanins were absorbed and occurred in body fluids mainly in the form of methylated, glucuronidated, and sulfated derivatives (in total, 21 derivatives were identified). The study showed that anthocyanins penetrated the B-CSF-B and their change in profile and concentration in the cerebrospinal fluid (CSF) resulted from fluctuations in concentrations of these compounds in blood plasma, although the presence of various cyanidin derivatives in CSF also depended on their chemical structure. The biological fate of chokeberry anthocyanins, from absorption into blood to penetration into CSF, was tracked to facilitate the design of further experimental procedures to determine the biological properties of these compounds, including potentially neuroprotective activities.

Anthocyanins: A Comprehensive Review of Their Chemical Properties and Health Effects on Cardiovascular and Neurodegenerative Diseases

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables. Dietary sources of anthocyanins include red and purple berries, grapes, apples, plums, cabbage, or foods containing high levels of natural colorants. Cyanidin, delphinidin, malvidin, peonidin, petunidin, and pelargonidin are the six common anthocyanidins. Following consumption, anthocyanin, absorption occurs along the gastrointestinal tract, the distal lower bowel being the place where most of the absorption and metabolism occurs. In the intestine, anthocyanins first undergo extensive microbial catabolism followed by absorption and human phase II metabolism. This produces hybrid microbial-human metabolites which are absorbed and subsequently increase the bioavailability of anthocyanins. Health benefits of anthocyanins have been widely described, especially in the prevention of diseases associated with oxidative stress, such as cardiovascular and neurodegenerative diseases. Furthermore, recent evidence suggests that health-promoting effects attributed to anthocyanins may also be related to modulation of gut microbiota. In this paper we attempt to provide a comprehensive view of the state-of-the-art literature on anthocyanins, summarizing recent findings on their chemistry, biosynthesis, nutritional value and on their effects on human health.

The Blood-Cerebrospinal Fluid Barrier Is Selective for Red Cabbage Anthocyanins and Their Metabolites

The study aim was to determine whether strongly bioactive hydrophilic red cabbage anthocyanins possess the ability to cross the blood-cerebrospinal fluid barrier (blood-CSF barrier) and whether there is a selectivity of this barrier toward these compounds. To fulfill objectives, red cabbage preparation, containing nonacylated and acylated anthocyanins, was administered to 16 sheep with implanted cannulas into the brain third ventricle, and next, within 10 h, blood, urine, and the cerebrospinal fluid (CSF) were collected and analyzed with HPLC-MS/MS. Though, in blood plasma and urine after red cabbage intake, both, acylated and nonacylated anthocyanins and their metabolites occurred, but only nonacylated derivatives were present in the CSF, and their changes in the profile and concentration in the CSF resulted from the fluctuation of these pigments' concentration and profile in blood, their different abilities to permeate via the blood-CSF barrier, and their transformations in this barrier. Results indicate that the blood-CSF barrier is selective for red cabbage anthocyanins.

Red Chinese Cabbage Transcriptome Analysis Reveals Structural Genes and Multiple Transcription Factors Regulating Reddish Purple Color

Reddish purple Chinese cabbage (RPCC) is a popular variety of Brassica rapa (AA = 20). It is rich in anthocyanins, which have many health benefits. We detected novel anthocyanins including cyanidin 3-(feruloyl) diglucoside-5-(malonoyl) glucoside and pelargonidin 3-(caffeoyl) diglucoside-5-(malonoyl) glucoside in RPCC. Analyses of transcriptome data revealed 32,395 genes including 3345 differentially expressed genes (DEGs) between 3-week-old RPCC and green Chinese cabbage (GCC). The DEGs included 218 transcription factor (TF) genes and some functionally uncharacterized genes. Sixty DEGs identified from the transcriptome data were analyzed in 3-, 6- and 9-week old seedlings by RT-qPCR, and 35 of them had higher transcript levels in RPCC than in GCC. We detected cis-regulatory motifs of MYB, bHLH, WRKY, bZIP and AP2/ERF TFs in anthocyanin biosynthetic gene promoters. A network analysis revealed that MYB75, MYB90, and MYBL2 strongly interact with anthocyanin biosynthetic genes. Our results show that the late biosynthesis genes BrDFR, BrLDOX, BrUF3GT, BrUGT75c1-1, Br5MAT, BrAT-1,BrAT-2, BrTT19-1, and BrTT19-2 and the regulatory MYB genes BrMYB90, BrMYB75, and BrMYBL2-1 are highly expressed in RPCC, indicative of their important roles in anthocyanin biosynthesis, modification, and accumulation. Finally, we propose a model anthocyanin biosynthesis pathway that includes the unique anthocyanin pigments and genes specific to RPCC.

Comparative Analysis of the Metabolic Profiles of Yellow- versus Black-Seeded Rapeseed Using UPLC-HESI-MS/MS and Transcriptome Analysis

The high levels of secondary metabolites in rapeseed play important roles in determining the oil quality and feeding value. Here, we characterized the metabolic profiles in seeds of various yellow- and black-seeded rapeseed accessions. Two hundred and forty-eight features were characterized, including 31 phenolic acids, 54 flavonoids, 24 glucosinolates, 65 lipid compounds, and 74 other polar compounds. The most abundant phenolic acids and various flavonoids (epicatechin, isorhamnetin, kaempferol, quercetin, and their derivatives) were widely detected and showed significant differences in distribution between the yellow- and black-seeded rapeseed. Furthermore, the related genes (e.g., BnTT3, BnTT18, BnTT10, BnTT12, and BnBAN) involved in the proanthocyanidin pathway had lower expression levels in yellow-seeded rapeseed, strongly suggesting that the seed coat color could be mainly determined by the levels of epicatechin and their derivatives. These results improve our understanding of the primary constituents of rapeseed and lay the foundation for breeding novel varieties with a high nutritional value.

Grown to be Blue-Antioxidant Properties and Health Effects of Colored Vegetables. Part II: Leafy, Fruit, and Other Vegetables

The current trend for substituting synthetic compounds with natural ones in the design and production of functional and healthy foods has increased the research interest about natural colorants. Although coloring agents from plant origin are already used in the food and beverage industry, the market and consumer demands for novel and diverse food products are increasing and new plant sources are explored. Fresh vegetables are considered a good source of such compounds, especially when considering the great color diversity that exists among the various species or even the cultivars within the same species. In the present review we aim to present the most common species of colored vegetables, focusing on leafy and fruit vegetables, as well as on vegetables where other plant parts are commercially used, with special attention to blue color. The compounds that are responsible for the uncommon colors will be also presented and their beneficial health effects and antioxidant properties will be unraveled.

Identification and Characterization of Major Constituents in Different-Colored Rapeseed Petals by UPLC-HESI-MS/MS

Oilseed rape (Brassica napus L.) is the second highest yielding oil crop worldwide. In addition to being used as an edible oil and a feed for livestock, rapeseed has high ornamental value. In this study, we identified and characterized the main floral major constituents, including phenolic acids and flavonoids components, in rapeseed accessions with different-colored petals. A total of 144 constituents were identified using ultrahigh-performance liquid chromatography-HESI-mass spectrometry (UPLC-HESI-MS/MS), 57 of which were confirmed and quantified using known standards and mainly contained phenolic acids, flavonoids, and glucosinolates compounds. Most of the epicatechin, quercetin, and isorhamnetin derivates were found in red and pink petals of B. napus, while kaempferol derivates were in yellow and pale white petals. Moreover, petal-specific compounds, including a putative hydroxycinnamic acid derivative, sinapoyl malate, 1-O-sinapoyl-β-d-glucose, feruloyl glucose, naringenin-7-O-glucoside, cyanidin-3-glucoside, cyanidin-3,5-di-O-glucoside, petunidin-3-O-β-glucopyranoside, isorhamnetin-3-O-glucoside, kaempferol-3-O-glucoside-7-O-glucoside, quercetin-3,4'-O-di-β-glucopyranoside, quercetin-3-O-glucoside, and delphinidin-3-O-glucoside, might contribute to a variety of petal colors in B. napus. In addition, bound phenolics were tentatively identified and contained three abundant compounds (p-coumaric acid, ferulic acid, and 8-O-4'-diferulic acid). These results provide insight into the molecular mechanisms underlying petal color and suggest strategies for breeding rapeseed with a specific petal color in the future.

Natural color pigments: oxidative stability and degradation kinetics during storage in thermally pasteurized vegetable purees

BACKGROUND

Package oxygen transmission rate (OTR) can affect the stability of natural color pigments such as anthocyanins, betalains and chlorophylls in foods during storage. In the present study, we investigated the oxygen sensitivity of selected pigments in thermally pasteurized vegetable purees held at a refrigeration temperature. We modulated the oxygen ingress in packaging using multilayer films with OTRs of 1, 30 and 81 cm3  m-2  day-1 . Red cabbage, beetroot and pea purees were vacuum packed, pasteurized to achieve a cumulative lethality ofP 90 ° C 10 ° C = 12.8-13.4 min and stored at 7 °C for 80 days.

RESULTS

Anthocyanins were relatively stable (< 4% losses), regardless of the film OTR. Betalains showed the highest sensitivity to different OTRs, with total losses varying from 4% to 49% at the end of storage and showing significant differences (P < 0.05) among the three films. Chlorophylls showed no significant difference (P > 0.05) in sensitivity to film OTRs. However, continuous degradation of chlorophylls was observed for all film types, with total chlorophyll losses ranging from 33% to 35%. Overall color differences (ΔE) at the end of storage for cabbage, beet and pea puree were between 0.50-1.70, 1.00-4.55 and 7.41-8.08, respectively. Betalains and chlorophylls degradation followed first-order and fractional conversion kinetics, whereas ΔE followed zero-order and fractional conversion kinetics during storage.

CONCLUSION

All three pigments behaved differently to oxygen ingress during storage. Low to medium barrier films are suitable for products containing red cabbage anthocyanins. High barrier films are must for betalains, whereas medium to high barrier films are suitable for chlorophyll-containing products. © 2019 Society of Chemical Industry.

Molar absorptivities (ε) and spectral and colorimetric characteristics of purple sweet potato anthocyanins

Purple sweet potato, a source of acylated cyanidin and peonidin derivatives, is commercially available as a food colorant. Our objectives were to determine molar absorptivities (ε), spectral and colorimetric properties of purple sweet potato anthocyanins. Anthocyanins were isolated by semi-preparative HPLC, weighed, dried, and redissolved in acidic methanol or water. Anthocyanins were diluted in pH 1-9; ε, spectra, and color were measured on the methanolic and aqueous solutions. Higher ε were obtained in 0.1% HCl methanol (10,797-31,257 L/(mol × cm)) than in aqueous solution pH 1 (8861-24,303 L/(mol × cm)). Peonidin-3-sophoroside-5-glucoside had greatest ε in pH 1, but in alkaline pH, ε of acylated Peonidin-3-sophoroside-5-glucoside derivatives were greatest. Generally monoacylation decreased ε while diacylation increased ε. Location of acylation also affected ε of two Peonidin isomers (pH 1: 15,999 and 21,011 L/(mol × cm)). All anthocyanins expressed red-pink hues (330°-13.2°) in acidic pH and blues (230°-262°) in alkaline pH.

Comparative Metabolic Profiling of Green and Purple Pakchoi (Brassica Rapa Subsp. Chinensis)

Pakchoi (Brassica rapa subsp. chinensis) is cultivated for its nutritional value, particularly with regard to vitamins, minerals and dietary fibers. However, limited metabolic information is available on the phyto-nutritional traits of pakchoi. Our GC-TOF MS analysis showed that green pakchoi has higher contents of carbon metabolism-associated metabolites such as sugars, sugar derivatives and inositol, while purple pakchoi has higher levels of nitrogen metabolism-associated metabolites such as amino acids and amino acid derivatives. To compare the content and composition of secondary metabolites in green and purple pakchoi, we analyzed phenylpropanoid-derived compounds and anthocyanins in mature leaves using an HPLC-UV system. This analysis identified 9 phenylpropanoid-derived compounds and 12 anthocyanins in the mature leaves of green and purple pakchoi. The level of rutin was significantly higher in purple pakchoi compared with green pakchoi, consistent with the expression of phenylpropanoid biosynthetic genes in the two pakchoi cultivars. The data obtained from this comprehensive metabolic profiling would be helpful to improve our understanding of the nutritional values of pakchoi cultivars as food sources.

New strategy for determination of anthocyanins, polyphenols and antioxidant capacity of Brassica oleracea liquid extract using infrared spectroscopies and multivariate regression

A new method was developed to determine the antioxidant properties of red cabbage extract (Brassica oleracea) by mid (MID) and near (NIR) infrared spectroscopies and partial least squares (PLS) regression. A 70% (v/v) ethanolic extract of red cabbage was concentrated to 9° Brix and further diluted (12 to 100%) in water. The dilutions were used as external standards for the building of PLS models. For the first time, this strategy was applied for building multivariate regression models. Reference analyses and spectral data were obtained from diluted extracts. The determinate properties were total and monomeric anthocyanins, total polyphenols and antioxidant capacity by ABTS (2,2-azino-bis(3-ethyl-benzothiazoline-6-sulfonate)) and DPPH (2,2-diphenyl-1-picrylhydrazyl) methods. Ordered predictors selection (OPS) and genetic algorithm (GA) were used for feature selection before PLS regression (PLS-1). In addition, a PLS-2 regression was applied to all properties simultaneously. PLS-1 models provided more predictive models than did PLS-2 regression. PLS-OPS and PLS-GA models presented excellent prediction results with a correlation coefficient higher than 0.98. However, the best models were obtained using PLS and variable selection with the OPS algorithm and the models based on NIR spectra were considered more predictive for all properties. Then, these models provided a simple, rapid and accurate method for determination of red cabbage extract antioxidant properties and its suitability for use in the food industry.

Anthocyanins in perilla plants and dried leaves

High-quality perilla leaves are purple on upper and lower surfaces and have a good aroma. The Japanese Pharmacopoeia specifies the content of essential oils in perilla leaves but not that of anthocyanins. Several reports have described the chemical species of anthocyanins in red perilla, but a complete analysis of anthocyanins in perilla has not been reported. In this study, the anthocyanins in the leaves of cultivated and wild species of perilla and those in commercially available perilla herbs were studied. Red perilla and most P. citriodora strains accumulate cyanidin derivatives that differ in the acyl group on the glucose moiety at the 3-O- and 5-O-positions of the anthocyanins. Several strains of P. citriodora contain cyanidin derivatives that are different from those in red perilla and most P. citriodora species. Green perilla and wild species other than P. citriodora do not contain foliar anthocyanins. The anthocyanins in commercially available perilla herbs and natural dyes made from red perilla were in agreement with those in fresh red perilla leaves and most P. citriodora samples. The amounts and types of anthocyanins were not associated with place of cultivation, although some changes occurred due to degradation during storage. These results provide clues regarding the biosynthesis of anthocyanins in perilla and the evolution of red perilla. The characteristics and stability of anthocyanins are discussed.

Identification and Characterization of Anthocyanin Biosynthesis-Related Genes in Kohlrabi

Kohlrabi (Brassica oleracea var. gongylodes L.) is an important vegetable of the Brassicaceae family. The main edible part of kohlrabi is the swollen stem. The purple cultivars make anthocyanin mainly in the peel of the swollen stem, while in the leaf, it is limited to the midrib, but green cultivars do not. Anthocyanins are advantageous for both plants as well as humans. Two anthocyanin compounds were detected by high pressure liquid chromatography (HPLC) only in the peel of the purple kohlrabi cultivar. Three MYBs, three bHLHs, and one WD40 TF were identified as the candidate regulatory genes in kohlrabi. There was an abundance of transcript levels for the late biosynthetic genes more specifically for BoF3'H, BoDFR, BoLDOX, and BoGST in the purple peel while scarcely detectable in other tissues for both cultivars. The expression of BoPAP2 and BoTT8 was higher in the peel of the purple cultivar than the green cultivar. The expression of BoMYBL2.2 orthologue of Arabidopsis MYBL2, a negative regulator of anthocyanins, was dramatically decreased in the purple peel. The expression of BoACO1, a key gene for ethylene biosynthesis, and BoNCED3, an important gene of the ABA pathway, was down- and upregulated, respectively, in the peel of purple kohlrabi.

Transcriptome analysis and metabolic profiling of green and red kale (Brassica oleracea var. acephala) seedlings

Kale (Brassica oleracea var. acephala) is a rich source of numerous health-benefiting compounds, including vitamins, glucosinolates, phenolic compounds, and carotenoids. However, the genetic resources for exploiting the phyto-nutritional traits of kales are limited. To acquire precise information on secondary metabolites in kales, we performed a comprehensive analysis of the transcriptome and metabolome of green and red kale seedlings. Kale transcriptome datasets revealed 37,149 annotated genes and several secondary metabolite biosynthetic genes. HPLC analysis revealed 14 glucosinolates, 20 anthocyanins, 3 phenylpropanoids, and 6 carotenoids in the kale seedlings that were examined. Red kale contained more glucosinolates, anthocyanins, and phenylpropanoids than green kale, whereas the carotenoid contents were much higher in green kale than in red kale. Ultimately, our data will be a valuable resource for future research on kale bio-engineering and will provide basic information to define gene-to-metabolite networks in kale.

Inhibitory Potential of Red Cabbage against Digestive Enzymes Linked to Obesity and Type 2 Diabetes

Assays of the inhibitory potential against enzymes involved in carbohydrate and lipid digestion (α-amylase, α-glucosidase, and lipase) as well as the total contents of phenolics and anthocyanins, anthocyanin profile, and antioxidant capacity revealed significant differences (p < 0.05) between five varieties of red cabbage. Among the varieties, the highest inhibitory activity against α-glucosidase (IC₅₀ = 3.87 ± 0.12 mg dry weight (DW) of cabbage/mL) and lipase (IC₅₀ = 1.57 ± 0.06 mg DW/mL) was exhibited by the Koda variety, which showed the highest antioxidant capacity in ABTS (Trolox equivalent antioxidant capacity (TEAC) = 141 ± 4.71 μmol/g DW) and ferric-reducing antioxidant power (TEAC = 125 ± 1.94 μmol/g DW) assays and had the highest total phenolics level (19.6 ± 0.48 mg/g DW). The highest total anthocyanin content (12.0 ± 0.16 mg/g DW) and inhibitory activity against α-amylase (IC₅₀ = 69.0 ± 3.65 mg DW of cabbage/mL) was shown by the Kissendrup variety. The anthocyanin profiles of these two varieties were characterized by the highest percentages of diacylated cyanidin derivatives. There was no correlation between the contents of phenolic compounds and lipase inhibitory activity, but inhibition of α-amylase was correlated with concentrations of monoacylated and diacylated anthocyanins, while inhibition of α-glucosidase increased with total phenolics and diacylated anthocyanins levels.

Anthocyanin rich extract of Brassica oleracea L. alleviates experimentally induced myocardial infarction

Cardioprotective potential of anthocyanin rich red cabbage extract (ARCE) was assessed in H₂O₂ treated rat neonatal cardiomyoblasts (H9c2 cells) and isoproterenol (ISO) induced rodent model of myocardial infarction. H₂O₂ treated H9c2 cells recorded cytotoxicity (48–50%) and apoptosis (57.3%), the same were reduced in presence of ARCE (7–10% & 12.3% respectively). Rats pretreated with ARCE for 30 days followed by ISO treatment recorded favourable heart: body weight ratio as compared to ISO treated group. Also, the mRNA levels of enzymatic antioxidants (sod and catalase) and apoptotic genes (bax and bcl-2) in ARCE+ISO treated group were similar to the control group suggesting that ARCE pretreatment prevents ISO induced depletion of enzymatic antioxidants and apoptosis. Histoarchitecture of ventricular tissue of ISO treated group was marked by infracted areas (10%) and derangement of myocardium whereas, ARCE+ISO treated group (4.5%) recorded results comparable to control (0%). ARCE+ISO treated group accounted for upregulation of caveolin-3 and SERCA2a expression as compared to the ISO treated group implying towards ARCE mediated reduction in membrane damage and calcium imbalance. Molecular docking scores and LigPlot analysis of cyanidin-3-glucoside (-8.7 Kcal/mol) and delphinidin-3-glucoside (-8.5 Kcal/mol) showed stable hydrophobic and electrostatic interactions with β₁ adrenergic receptor. Overall this study elucidates the mechanism of ARCE mediated prevention of experimentally induced myocardial damage.

Effect of fermentation and sterilization on anthocyanins in blueberry

BACKGROUND

Blueberry products have various health benefits due to their high content of dietary anthocyanins. The aim of this study was to investigate the impact of fermentation and sterilization on total anthocyanin content, composition and some quality attributes of blueberry puree. The blueberry puree used here was fermented for 40 h at 37 °C by Lactobacillus after sterilization. The method of ultra-performance liquid chromatography-mass spectrometry was optimized for the rapid analysis of anthocyanins. Quality attributes including pH, color, total soluble solids and viscosity were measured.

RESULTS

A total of 21 anthocyanins and five anthocyanidins were quantified by ultra-performance liquid chromatography. Fermented blueberry had reduced total anthocyanin content (29%) and levels of individual anthocyanins compared with fresh blueberry. Total anthocyanin content was decreased 46% by sterilization, and different degradation behavior of individual anthocyanin was appeared between fermented and sterilized-fermented blueberry puree. Fermentation and sterilization decreased the total soluble solids and pH and changed color parameters, while minimally influencing viscosity.

CONCLUSIONS

The loss of total anthocyanin content by fermentation was related to the unstable structure of blueberry anthocyanins. Anthocyanins are sensitive to temperature (>80 °C), and degradation of anthocyanins by sterilization in blueberry should be considered in the fermentation procedure. © 2016 Society of Chemical Industry.