Food Pigments Research Articles

Improving the medium composition for the production of the natural blue-violet pigment violacein by a new Janthinobacterium sp. isolate.

The interest in natural compounds has increased primarily due to their beneficial health and environmental aspects. However, natural sources of some compounds, such as bluish pigments, are limited, requiring the development of efficient processes to meet commercial demands. This study isolated a blue-violet bacterium from spoiled cooked rice and identified it as a potential new species of Janthinobacterium through 16S rDNA analysis. Ultra-high performance liquid chromatography-tandem mass spectrometry analyses confirmed that the blue-violet pigment violacein was responsible for the bluish color. In laboratory conditions, different carbon and nitrogen sources were evaluated in submerged culture media to enhance pigment production. Glycerol did not result in significant pigment production by this strain, as expected from previous reports. Instead, a culture medium composed of yeast extract and fructose yielded higher pigment production, reaching about 113.68±16.68 mg l-1 after 120 h. This result provides crucial insights for future studies aiming for sustainable and commercially viable violacein production. Based on a bioeconomy concept, this approach has the potential to supply natural and economic bluish pigments for various industrial sectors, including pharmaceutical, cosmetic, and food.

Engineered microenvironments and pancreatic islet-on-chips for screening sugar substitute and antidiabetic compounds

Recent advancements in the food industry have rekindled interest in the safety of food additives, such as sugar substitutes and food pigments. Consequently, the main purpose of this study was to develop models that can more accurately predict the effects of these additives on the human body. In response to this demand, we have created an innovative pancreas islet-on-a-chip system featuring a concentration gradient generator and a perfusable 3D cell culture array. This setup facilitates the 3D culture of pseudo-islets under stable biochemical and biophysical conditions. When compared to static culture environments, our dynamic environment maintains islet cell viability at over 95 %, resulting in larger cell clusters that exhibit a higher tendency for aggregation up to 30 μm. Furthermore, the expression levels of key factors integral to islet development, namely INS-1, INS-2, and PDX-1, increased by 4.5-fold, 1.9-fold, and 5.8-fold respectively in the dynamic environment. Utilizing this sophisticated pancreas islet-on-a-chip model, we discovered that the consumption of sugar substitutes like erythritol and sucralose for 1 h does not impact insulin secretion levels. In contrast, the administration of glucagon-like peptide 1 (GLP-1), GLP-1 receptor (GLP-1R) agonist exendin-4, curcumin, and a combination therapy group led to a substantial increase in insulin secretion levels (p < 0.01). Such engineered microenvironments and pancreatic islet-on-chips offer a groundbreaking platform for evaluating sugar substitutes and antidiabetic compounds.

Hydroxysafflor yellow A, a natural food pigment, ameliorates atherosclerosis in ApoE−/− mice by inhibiting the SphK1/S1P/S1PR3 pathway

AbstractAtherosclerosis (AS) is the pathologic basis of many cardiovascular diseases (CVDs). Hydroxysafflor yellow A (HSYA) is a valuable natural food pigment that has been reported to have significant health‐promoting abilities. However, the anti‐AS efficacy and mechanisms of HSYA have not yet been characterized. Here, we found that treatment of apolipoprotein A (ApoE) knockout (ApoE−/−) mice with HSYA markedly ameliorated atherosclerosis evidenced by decreased levels of lipids, sphingosine‐1‐phosphate (S1P), inflammatory factors, oxidative stress, vascular endothelial permeability, and endothelial damage. Moreover, mechanistic studies revealed that HSYA treatment downregulated the expression of aortic sphingosine kinase 1 (SphK1), sphingosine‐1‐phosphate receptor 3 (S1PR3), Ras homolog family member A (RhoA), Rho‐associated coiled‐coil containing protein kinase (ROCK), and filamentous actin (F‐actin). The results of administration with HSYA reversed the effects of SphK1 agonist and S1PR3 agonist on oxidized low‐density lipoprotein (ox‐LDL)‐induced vascular endothelial cell migration ability and F‐actin expression, and decreased RhoA/ROCK protein expression further confirmed the conclusion that HSYA reduced vascular endothelial permeability by modulating the SphK1/S1P/S1PR3/RhoA/ROCK signaling pathway, thereby exerting anti‐atherosclerotic effects. Overall, this study indicated that HSYA might be a therapeutic candidate for the treatment of AS.

Optimizing Encapsulation of Active Compounds of Carrot By-Product in TPP-Chitosomes.

Liposomes coated with chitosan by ionic gelation with tripolyphosphate (TPP-chitosomes) are interesting particles for stabilizing active compounds. However, the encapsulation condition must be optimized. The aim of this study was to optimize the encapsulation of phenolics and carotenoids of carrot pomace in TPP-chitosomes by using a Central Composite Design 23 and response surface methodology. The independent variables were the phospholipid (0.8-4.2 mg/mL), chitosan (2.6-9.4 mg/mL), and carrot pomace (4-14 g/100 mL of ethanol) concentrations; the responses were the encapsulation efficiency in TPP-chitosomes (EE) of phenolics, a-carotene, and b-carotene and the particle size and zeta potential of the particles. The zeta potential ranged from +17 to +37 mV, indicating that the liposomes were coated with chitosan and that the particle sizes were in the nanometric to submicrometric scale. The optimized condition for encapsulating carotenoids was 2.5 mg/mL phospholipids, 6.0 mg/mL chitosan, and 12 g of carrot pomace/100 mL of ethanol. In this condition, the EE of phenolics and α- and β-carotene was 95%, 98%, and 99%, respectively. Therefore, TPP-chitosomes containing encapsulated phenolics and carotenoids, which can be obtained from agro-industrial by-products, have potential application as natural pigments in food or cosmetics. TPP-chitosomes can also be used to encapsulate other types of natural pigments.

Novel stabilization of chlorophyll by sea cucumber (Apostichopus japonicas) protein: Multi-spectral and molecular dynamics analysis

The instability of chlorophyll (Chl) during processing results in color loss, posing significant challenges to its application. This study presents a novel method for stabilizing Chl through the formation of a Chl-protein complex with sea cucumber (Apostichopus japonicas) protein (AJP). The Chl-AJP complex exhibited enhanced color and thermal stability over free Chl. DSC analysis revealed a 16 °C increase in the Td of the complex, while thermodynamic results indicated a 62.82% decrease in the degradation rate of the complex. Analysis including multi-spectral techniques and molecular docking and dynamics simulations elucidated the complex's stabilizing interactions, such as van der Waals forces, hydrogen bonding, and hydrophobic interactions. These findings were experimentally confirmed, showcasing AJP's potential as both a stabilizer for Chl and a carrier for hydrophobic bioactive compounds. The study introduces a pioneering approach to Chl stabilization, paving the way for its application in high-end dietary supplements and enhancing the bioavailability of natural pigments in nutraceuticals and functional foods.

Activation of a Silent Gene Cluster from the Endophytic Fungus Talaromyces sp. Unearths Cryptic Azaphilone Metabolites.

Fungal azaphilones have attracted widespread attention due to their significant potential as sources of food pigments and pharmaceuticals. Genome mining and gene cluster activation represent powerful tools and strategies for discovering novel natural products and bioactive molecules. Here, a putative azaphilone biosynthetic gene cluster lut from the endophytic fungus Talaromyces sp. was identified through genome mining. By overexpressing the pathway-specific transcription factor LutB, five new sclerotiorin-type azaphilones (1, 6, 8, and 10-11) together with seven known analogues (2-5, 7, 9, 12) were successfully produced. Compounds 8 and 9 exhibited antibacterial activity against Bacillus subtilis with MIC values of 64 and 16 μg/mL, respectively. Compound 11 showed cytotoxic activity against HCT116 and GES-1 with IC50 values of 10.9 and 4.9 μM, respectively, while 1, 4, 5, and 7-10 showed no obvious cytotoxic activity. Gene inactivation experiments confirmed the role of the lut cluster in the production of compounds 1-12. Subsequent feeding experiments unveiled the novel functional diversity of the dual megasynthase system. Furthermore, a LutC-LutD binary oxidoreductase system was discovered, and in combination with DFT calculations, the basic biosynthetic pathway of the sclerotiorin-type azaphilones was characterized. This study provided a good example for the discovery of new azaphilones and further uncovered the biosynthesis of these compounds.

Immunotoxicity of 2-Acetyl-4-tetrahydroxybutylimidazole in BALB/c mice with different vitamin B6 nutritional statuses

Caramel color is a widely used food pigment, and 2-Acetyl-4-tetrahydroxybutylimidazole (THI) is a by-products of Class III caramel color. Some studies have shown that THI can reduce the number of peripheral blood lymphocytes. However, the comprehensive mechanism of THI immunotoxicity requires further study. In this study, the effects of THI on lymphocyte count, humoral immunity, cellular immunity and nonspecific immunity were determined and the effect of the nutritional status of VB6 on THI immunotoxicity was evaluated. Female BALB/c mice were divided into 3 groups and fed chow containing different doses of VB6: VB6-normal (6 mg/kg VB6), VB6-deprived (0.5 mg/kg VB6) or VB6-enhanced (12 mg/kg VB6) feed. Each group was further divided into 4 subgroups and treated with THI (0.5, 2.5 or 12.5 mg/kg bw) or the solvent control by gavage for 30 days. The thymic cortical thickness was measured with ViewPoint; the proportions of major immune cells and T cells in peripheral blood and tissues were detected via flow cytometry; the transformation and proliferation abilities of T and B cells were detected via T and B lymphocyte proliferation assays; NK cell activity was assessed via lactate dehydrogenase assays; humoral immune function was assessed via plaque-forming cell assays; and the immune function of T lymphocytes was assessed via delayed type hypersensitivity assays. The results showed that compared with those in the corresponding control group, the white blood cell count and lymphocyte count decreased significantly in all the VB6-deprived groups, in the 2.5 and 12.5 mg/kg VB6 groups, and in the 12.5 mg/kg VB6-enhanced group. With increasing THI dose, the thymic cortical layer became thinner. In the thymus, THI increased the proportions of CD3+ T cells and mature CD8+ T cells and decreased the proportions of immature double-positive, double-negative T cells and CD69-expressing lymphocytes. The proportions of naïve T cells and Tcm (central memory T) cells related to homing decreased. The proportion of mature T cells in the spleen decreased significantly. The proliferation of T cells stimulated by ConA decreased after THI exposure. VB6-deficient mice were more sensitive to THI immunotoxicity, and supplementation with VB6 had a certain protective effect on these mice. The results of the PFC and NK cell activity assays indicated that THI exposure might not affect humoral immune or innate immune function.

The effects of environmental factors on the synthesis of water-soluble Monascus red pigments via submerged fermentation: a review.

Monascus pigments (MPs) have been used as natural food pigments for many years. There is a high demand for Monascus red pigments (MRPs) to enhance color and for antibacterial and cancer prevention therapies in food and medicine. Most MRPs are not water soluble, and the yield of water-soluble MRPs is naturally low. On the other hand, water-soluble MRP is more cost effective for application in industrial mass production. Therefore, it is important to improve the yield of water-soluble MRPs. Environmental factors have a significant influence on the synthesis of water-soluble MRPs, which is crucial for the development of industrial production of water-soluble MRPs. This review introduces the biosynthetic pathways of water-soluble MRPs and summarizes the effects of environmental factors on the yield of water-soluble MRPs. Acetyl coenzyme A (acetyl-CoA) is a precursor for MPs synthesis. Carbon and nitrogen sources and the carbon/nitrogen ratio can impact MP production by regulating the metabolic pathway of acetyl-CoA. Optimization of fermentation conditions to change the morphology of Monascus can stimulate the synthesis of MPs. The appropriate choice of nitrogen sources and pH values can promote the synthesis of MRPs from MPs. Additives such as metal ions and non-ionic surfactants can affect the fluidity of Monascus cell membrane and promote the transformation of MRPs into water-soluble MRPs. This review will lay the foundation for the industrial production of water-soluble MRPs. © 2024 Society of Chemical Industry.

From sea to sea: Edible, hydrostable, and degradable straws based on seaweed-derived insoluble cellulose fibers and soluble polysaccharides

The widespread use of disposable plastic straws has caused a long-lasting environmental problem. Potential alternatives for plastic straws are far from satisfactory due to the low utility, poor water stability, and non-ideal natural degradability. In this work, an edible, hydrostable, and degradable straw was developed from the economically significant seaweed. Seaweed-derived insoluble cellulose fibers were used as the building block of the straw, and the soluble polysaccharide extracts were explored as the natural glue through the chelation with Ca2+. Repeated freeze-thawing was introduced to strengthen the molecular interactions, which further improved its mechanical stability and hydrostability. The straw exhibited remarkable natural degradability in open environments, particularly in marine-mimicking conditions. By incorporating pH-sensitive food pigments, the straws could indicate acid-base property of a beverage or even discriminate the freshness of milk. The versatile seaweed-derived straw adhered to the biocycle concept of “from sea to sea” to alleviate the burden of white pollution on oceans.

Beyond colors: The health benefits of maize anthocyanins

The anthocyanins (ACN) are watersoluble pigments present in the pericarp or aleurone layer of maize kernel. The authentic color landraces being grown by the farmers at a smaller scale restricted to local consumers. These color ears (cob with color kernels) which are receiving more prominence not only for their environment friendly and natural colorant properties but also to their numerous health benefits from edible food pigments. Since anthocyanin pigments have significant effects on animal health, it is also catching the attention of food processing companies as well as highend culinary markets. In this review, we have represented functional properties of anthocyanins present in maize. Earlier, studies best on in vitro tests were extrapolatory but now using cell models and animal trials are providing foolproof evidence for functional significance of corn anthocyanins. The mechanisms of action at the cellular and molecular level have been understood.

A critical review on the stability of natural food pigments and stabilization techniques

This comprehensive review article delves into the complex world of natural edible pigments, with a primary focus on their stability and the factors that influence them. The study primarily explores four classes of pigments: anthocyanins, betalains, chlorophylls and carotenoids by investigating both their intrinsic and extrinsic stability factors. The review examines factors affecting the stability of anthocyanins which act as intrinsic factors like their structure, intermolecular and intramolecular interactions, copigmentation, and self-association as well as extrinsic factors such as temperature, light exposure, metal ions, and enzymatic activities. The scrutiny extends to betalains which are nitrogen-based pigments, and delves into intrinsic factors like chemical composition and glycosylation, as well as extrinsic factors like temperature, light exposure, and oxygen levels affecting for their stability. Carotenoids are analyzed concerning their intrinsic and extrinsic stability factors. The article emphasizes the role of chemical structure, isomerization, and copigmentation as intrinsic factors and discusses how light, temperature, oxygen, and moisture levels influence carotenoid stability. The impacts of food processing methods on carotenoid preservation are explored by offering guidance on maximizing retention and nutritional value. Chlorophyll is examined for its sensitivity to external factors like light, temperature, oxygen exposure, pH, metal ions, enzymatic actions, and the food matrix composition. In conclusion, this review article provides a comprehensive exploration of the stability of natural edible pigments, highlighting the intricate interplay of intrinsic and extrinsic factors. In addition, it is important to note that all the references cited in this review article are within the past five years, ensuring the most up-to-date and relevant sources have been considered in the analysis.

Potential and Trends Processing of Shrimp Industry by-Products in Food: A Review

The shrimp processing industry represents the largest fisheries sector globally due to its high demand and market value. Generally, the only shrimp parts that are often produced in factories are in the form of headless and peeled shrimp (shrimp without skin and head), about 88.5%. During processing, by-products are produced and require proper treatment. Shrimp by-product production has increased dramatically in recent years, leading to waste collection, disposal and pollution problems. The trend of utilisation of shrimp by-products needs to be carried out because these by-products have the potential to produce innovative products that have added value and are sustainable. By-products such as shrimp heads and shells contain proteins, minerals, fats, amino acids and bioactive compound components that can be used as additives and raw materials. The purpose of this paper is to examine the potential utilization of shrimp processing industry by-products. By converting these by-products into value-added products such as bioplastic, flavouring, natural food pigments, shrimp oil, and protein hydrolysates. Processing using various conventional and enzymatic extraction methods has the potential to reduce by-products. Utilisation of shrimp by-products can provide an attractive alternative to reduce dependence on synthetic products in the food industry, while providing the added benefit of more efficient and environmentally friendly by-product management.

Food grade microalgae-based biopigments and their production technique versus synthetic colorants

In the food industry, synthetic color-active compounds can be added as additives to replace natural colors that are damaged during processing. This addition reduces the batch-to-batch fluctuation and increases the development of new or desired products that are appealing to consumers where natural colors are absent. Synthetic colorants cannot be produced by any bioprocess. In contrast, the Food and Drug Administration declared that algae such as Chlorella, Cryptothecodinium, Dunaliella Nannochloropsis, Nitzschia, Phaeodactylum, Schizochytrium, and Spirulina are trustable sources of food pigments as natural sources. These microalgae are photoautotrophic species and can be found on the "Generally Recognized as Safe-GRAS" list of food additives. Microalgae-derived pigments, which are also known as nutraceutical supplements, have been recently used in functional food products. Some of them are used as health and color supporters because of their excellent antioxidant properties that block oxidative reactions in lipid-rich food products. Their unique properties of being harmless to the environment were scientifically proven as well. As a result, the demand for their commercial use is increasing gradually. However, the bioprocess of algae on a huge scale is very limited due to some environmental factors and is hard to produce continuously. The scope of this review was to provide concise knowledge about biopigments extracted from microalgae and their production methods and to clarify the current implementations in the industry. Additionally, food-grade biopigments were compared with synthetic ones. The primary issues with bioprocesses used to produce colorants were highlighted, and as a result, the expected studies were discussed that would be conducted soon.

A review on mechanisms and impacts of cold plasma treatment as a non-thermal technology on food pigments.

Food characteristics like appearance and color, which are delicate parameters during food processing, are important determinants of product acceptance because of the growing trend toward more diverse and healthier diets worldwide, as well as the increase in population and its effects on food consumption. Cold plasma (CP), as a novel technology, has marked a new trend in agriculture and food processing due to the various advantages of meeting both the physicochemical and nutritional characteristics of food products with minimal changes in physical, chemical, nutritional, and sensorial properties. CP processing has a positive impact on food quality, including the preservation of natural food pigments. This article describes the influence of CP on natural food pigments and color changes in vegetables and fruits. Attributes of natural pigments, such as carotenoids, chlorophyll, anthocyanin, betalain, and myoglobin, are presented. In addition, the characteristics and mechanisms of CP processes were studied, and the effect of CP on mentioned pigments was investigated in recent literature, showing that the use of CP technology led to better preservation of pigments, improving their preservation and extraction yield. While certain modest and undesirable changes in color are documented, overall, the exposure of most food items to CP resulted in minor loss and even beneficial influence on color. More study is needed since not all elements of CP treatment are currently understood. The negative and positive effects of CP on natural food pigments in various products are discussed in this review.

Some novel bioactivities of Virgibacillus halodenitrificans carotenoids, isolated from Wadi El-Natrun lakes

Carotenoids come in second among the most frequent natural pigments and are utilized in medications, nutraceuticals, cosmetics, food pigments, and feed supplements. Based on recent complementary work, Virgibacillus was announced for the first time as a member of Wadi El-Natrun salt and soda lakes microbiota, identified as Virgibacillus halodenitrificans, and named V. halodenitrificans DASH; hence, this work aimed to investigate several in vitro medicinal bioactivities of V. halodenitrificans DASH carotenoids. The carotenoid methanolic extract showed antioxidant activity based on diphenylpicrylhydrazyl (DPPH) scavenging capacity with a half-maximal concentration (IC50) of 1.6 mg/mL as well as nitric oxide (NO) scavenging action expressed by an IC50 of 46.4 µg/mL. The extract showed considerable inhibitory activity for alpha-amylase (α-amylase) and alpha-glucosidase (α-glucosidase) enzymes (IC50 of 100 and 173.4 μg/mL, respectively). Moreover, the extract displayed selective anticancer activity against Caco-2 (IC50 = 138.96 µg/mL) and HepG-2 cell lines (IC50 = 31.25 µg/mL), representing colorectal adenocarcinoma and hepatoblastoma. Likewise, the extract showed 98.9 % clearance for human hepatitis C virus (HCV) using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), HCV-NS5B polymerase activity inhibition (IC50 = 27.4 µg/mL), and selective inhibitory activity against human coronavirus (HCoV 229E) using the plaque reduction assay (IC50 = 53.5 µg/mL). As far as we can tell, the anticancer, antiviral, and antidiabetic attributes of Virgibacillus carotenoids are, de novo, reported in this work which accordingly invokes further exploration of the other medicinal, biotechnological, and industrial applications of Virgibacillus and haloalkaliphilic bacteria carotenoids.

2D excitation-emission fluorescence mapping analysis of plant food pigments.

Homogeneous dispersion of plant food pigments is indispensable to study their characteristic fluorescence features for non-destructive rapid monitoring of food systems. However, it is highly challenging to obtain such optical grade homogenized stable dispersion of various plant pigments in aqueous media for tracing their precise fluorescence signatures. Herein, we demonstrate a unique strategy to disperse various pigments, such as chlorophylls, carotenoids and phenolic compounds by the high-speed shear-force mixing of fresh green and red bell peppers (Capsicum annuum) in an aqueous medium with followed centrifugation and filtration. An advanced FLuorescence Excitation-emission (FLE) mapping and optical absorption analysis from the optical grade aqueous bell peppers dispersion allow simultaneous probing of chlorophylls, phenolic compounds and carotenoids by their characteristic electronic transitions. The demonstrated sampling protocols and spectroscopic analysis will be highly beneficial to obtain advanced spectroscopic databases from different food materials for rapid food analysis and quality control.

Low-gluten shortbread enriched with sweet potato powder (Ipomoea batatas var. Portu Orange): quality and texture indicators

The chemical composition of sweet potato (Ipomoea batatas var. Portu Orange), grown in Ukraine, was studied to determine its potential in shortbread technology. Portu Orange sweet potato has a high content of starch (11.2 %), natural sugars (4.7 %), dietary fiber (3.8 %) and food pigments. To obtain the highest quality characteristics and preserve the antioxidant properties of sweet potato during drying, an innovative microwave vacuum drying method was used. This allowed us to produce Portu Orange sweet potato powder with a high content of starch (43 %), natural sugars (18 %), dietary fibre (14.6 %) and preservation of food colouring properties. According to organoleptic parameters, Portu Orange sweet potato has an orange color, which was formed with a combination of anthocyanin pigmentation of the skin (orange) and β-carotene pigmentation of the flesh (light orange). In shortbread technology, Portu Orange sweet potato is used in powder form, which is an alternative to starch, sugar, orange food colorings, gluten-containing cereals and egg products. Portu Orange sweet potato powder was added to the shortbread recipe in the amount of 38 % to completely replace sugar and chicken eggs. The wheat flour in the recipe was replaced by 80 % low-gluten wheat flour and 20 % sweet potato powder. Compared to regular shortbread, the protein content increased by 24.3 % to 9.2 g/100 g, the dietary fiber content increased by 74.6 % to 10.3 g/100 g, and the ash content increased by 155.6 % to 2.3 g/100 g. The fat content of shortbread with sweet potato powder was reduced by 7.5 %, the carbohydrate content was reduced by 11.5 % and the energy value was reduced by 8 % to 407.8 kcal/100 g. Texture parameters were improved, making shortbread with sweet potato powder less hard, the hardness was reduced by 48 %, but at the same time the fracturability indicators were maintained, the fracturability was reduced by only 2 %, compared to the regular shortbread, which made it more acceptable to consumers. The obtained changes in the nutritional value of the shortbread, the improvement of the texture, the reduction of the gluten content and the presence of a high amount of biologically active substances confirm the effectiveness of using Portu Orange sweet potato powder for dietary low-gluten nutrition.

Hepatic effect of subacute Fe2 O3 nanoparticles exposure in Sprague-Dawley rats by LC-MS/MS based lipidomics.

Fe2 O3 nanoparticles (Fe2 O3 NPs) are one of the components of food additives numbered E172 and have been widely used as food pigments to color sweets. Although a large number of studies have reported that Fe2 O3 NPs could induce hepatotoxicity, the pathogenesis is still unclear, especially the subacute effects on the metabolic network after oral exposure. Therefore, it is necessary to define a highly sensitive strategy to investigate the potential effects of Fe2 O3 NPs and the mechanism. In this study, an animal experiment showed that Fe2 O3 NPs had no obvious toxic effects on body weight, histopathology and oxide stress. In order to further investigate the potential effects of Fe2 O3 NPs in vivo, a more sensitive LC-MS/MS-based lipidomic study was performed. The results of multivariate statistical analysis and western blot analysis showed that Fe2 O3 NP exposure significantly affects the hepatic glycerophospholipid metabolism, decreasing triacylglycerol, diglyceride, lysophosphatidylethanolamine and free fatty acids, and increasing phosphatidylcholine, lysophosphatidylinositol and coenzyme Q9. These data provide further insight into the hepatic subacute effects of Fe2 O3 NPs obtained by conventional toxicology methods.

The Effect of Storage and Pasteurization (Thermal and High-Pressure) Conditions on the Stability of Phycocyanobilin and Phycobiliproteins.

The utilization of natural blue pigments in foods is difficult as they are usually unstable during processing and the commonly applied pH. The current study focuses on natural blue pigment, possessing antioxidant properties, found in Arthrospira platensis (spirulina), and phycobiliproteins (PBP). These pigments are a complex of conjugated protein and non-protein components, known as phycocyanobilin. PBP has low stability during pasteurization (high-pressure or heat treatments), resulting in protein denaturation and color deterioration that limits the application. The phycocyanobilin pigment might also be liable to oxidation during pasteurization and storage, resulting in color deterioration. Yet, the instability of the pigment phycocyanobilin during the pasteurization process and storage conditions was never studied before, limiting the comprehensive understanding of the reasons for PBP instability. In this study, the stability of phycocyanobilin under high-pressure and high-temperature conditions was compared to the stability of phycobiliproteins. We revealed that phycobiliproteins have a higher color deterioration rate at 70-80 °C than at high-pressure (300-600 MPa) whereas phycocyanobilin remained stable during high-pressure and heat processing. During storage at pH 7, phycocyanobilin was oxidized, and the oxidation rate increased with increasing pH, while at lower pH phycocyanobilin had low solubility and resulted in aggregation.

Microalgae-Derived Pigments for the Food Industry.

In the food industry, manufacturers and customers have paid more attention to natural pigments instead of the synthetic counterparts for their excellent coloring ability and healthy properties. Microalgae are proven as one of the major photosynthesizers of naturally derived commercial pigments, gaining higher value in the global food pigment market. Microalgae-derived pigments, especially chlorophylls, carotenoids and phycobiliproteins, have unique colors and molecular structures, respectively, and show different physiological activities and health effects in the human body. This review provides recent updates on characteristics, application fields, stability in production and extraction processes of chlorophylls, carotenoids and phycobiliproteins to standardize and analyze their commercial production from microalgae. Potential food commodities for the pigment as eco-friendly colorants, nutraceuticals, and antioxidants are summarized for the target products. Then, recent cultivation strategies, metabolic and genomic designs are presented for high pigment productivity. Technical bottlenecks of downstream processing are discussed for improved stability and bioaccessibility during production. The production strategies of microalgal pigments have been exploited to varying degrees, with some already being applied at scale while others remain at the laboratory level. Finally, some factors affecting their global market value and future prospects are proposed. The microalgae-derived pigments have great potential in the food industry due to their high nutritional value and competitive production cost.