Food Colorants Research Articles

Development and stability evaluation of double emulsions enriched with Anthocyanins from Juçara

This study aimed to develop double emulsions enriched with anthocyanins extracted from juçara, a fruit rich in bioactive compounds with antioxidant properties. Anthocyanins are promising natural colorants but present instability to pH and temperature variations, limiting their application. Encapsulation in double emulsions (W/O/W) is an effective solution to increase the stability and retention of these compounds. The main objective was to develop and evaluate the stability of the double emulsions, aiming to protect the anthocyanins during processing. The methodology included the anthocyanins extraction from juçara and the formation of primary emulsions, followed by incorporation into external aqueous phases, testing different (W/O)/W proportions and concentrations of Arabic gum. The most stable double emulsion showed higher anthocyanin retention, with an encapsulation efficiency of 98.04%. The double emulsion system proved effective in protecting anthocyanins against different pHs, temperatures, and storage times, highlighting its potential for application as natural colorants in foods.

Antioxidant Activity of Anthocyanins and Anthocyanidins: A Critical Review

Anthocyanins are the main plant pigments responsible for the color of flowers, fruits, and vegetative organs of many plants, and are applied also as safe food colorants. They are efficient antioxidants. In this review, the reactivity of anthocyanins and their aglycones, anthocyanidins, in the main antioxidant assays, and their reactions with reactive oxygen and nitrogen species, effects of interactions with other compounds and metal ions on the antioxidant activity of anthocyanins and the electrochemical properties of anthocyanins are presented. Numerous cases of attenuation of oxidative stress at the cellular and organismal levels by anthocyanins are cited. The direct and indirect antioxidant action of anthocyanins, the question of the specificity of anthocyanin action in complex extracts, as well as limitations of cellular in vitro assays and biomarkers used for the detection of antioxidant effects of anthocyanins, are critically discussed.

Valorization of coconut (Cocos nucifera L.) testa as a biocolourant

IntroductionCoconut testa, a by-product of the coconut processing industry, is currently underutilised. This study aimed to extract a coconut testa-based food colourant using various organic solvents and physical methods, and to utilise this colourant in food product preparation.MethodsDifferent organic solvents, along with various time and temperature combinations, were employed for colourant extraction using both a laboratory-scale water bath and ultrasonication. The colour coordinate values (CIELab) of the testa-derived colourants were measured, and the colourants were screened for various phytochemicals. The in vitro antioxidant potential of the testa colourant was assessed by quantifying total phenolics, and the phytochemical composition, including monomeric anthocyanins, was evaluated.ResultsThe study determined the optimal combinations of organic solvents, temperature and time to obtain extracts with maximum antioxidant activity and total phenolic content (TPC). Acidified ethanol-based extracts of testa colourants yielded highest polyphenol content (154.39 ± 2.63 mg GAE/g) and flavonoids content (53.65 ± 0.62 mg QE/g). Similarly, ethanol-based extractants of coconut testa produced high anthocyanin content [823.02 ± 1.81 mg Cy-3-glc equivalents (C3GE)/100 g]. Acidified (0.3 M HCl) solvents at relatively high temperature and time combinations exhibited high antioxidant potential of testa colourant, as measured by CUPRAC, FRAP, and DPPH assays. Following the foam mat drying process of the colourant, a mature coconut water-based jelly was prepared by incorporating the testa colourant extracted with acidified ethanol.DiscussionThis study highlights the biochemical and antioxidant potential of the food colorant derived from coconut testa and explores its suitability for functional food applications. Therefore, coconut testa extract serves a dual purpose: it enhances the aesthetic appeal of food as a colourant and provides significant health-promoting properties due to its high anthocyanin content. Insights from this study could help in promoting the valorization of one of the beneficial by products of coconut industry.

Protective Role of Anthraquinone Purpurin Against Cardiotoxicity Induced by Isoproterenol in Adult Wistar Rats

Background Purpurin are naturally occurring anthraquinones derived from the roots of Rubia species. Purpurin is a red-colored bioactive compound commonly used as a food colorant. In ancient times, Rubia species plants were used in Chinese medicine to treat rheumatoid arthritis. Research studies have proven purpurin exerts antimicrobial, neuromodulatory, antigenotoxic, anti-inflammatory, anticancer, and antioxidant effects. The present investigation was proposed to evaluate the efficacy of purpurin against myocardial infarction in rats. Materials and Methods Purpurin was pretreated in healthy adult male rats and subjected to a myocardial infarction with isoproterenol to assess the cardioprotective effect of purpurin. CRP, total protein, and uric acid levels were quantified to analyze the efficacy against myocardial infarction. Cardiac functional markers and antioxidant levels were measured to evaluate the role of purpurin on isoproterenol-induced myocardial infarction. Further to prove the cardioprotective efficacy of purpurin cardiac tissue ATPases and electrolytes were assessed in the experimental animals. The anti-inflammatory property of purpurin was analyzed by quantifying proinflammatory cytokines. Histopathological analysis of cardiac tissue was to confirm the protective effect of purpurin against isoproterenol-induced myocardial infarction. Results The present investigation demonstrated the significant protective effect of purpurin by decreasing the levels of CRP, uric acid levels, and total protein levels in myocardial infarction-induced rats. It restored the cardiac functional markers and glutathione system in the cardiac tissue of myocardial infarction-induced rats. It increased the levels of cardiac ATPases and reinstated the electrolytes in the cardiac tissue of myocardial infarction-induced rats. Purpurin significantly demonstrated an anti-inflammatory and cardioprotective effect that was evidenced with histopathological analysis. Conclusion Our findings prove purpurin suppresses the proinflammatory response of isoproterenol treatment and exerts a cardioprotective effect in myocardial infarction-induced rats.

Potential for Allergic Contact Dermatitis in Popular Depilatory Wax Hair Removal Practices and Ingredients.

Allergic contact dermatitis (ACD) is a type IV delayed hypersensitivity reaction that can commonly arise from exposure to allergens in personal care and cosmetic products. Depilatory waxing, a common hair removal practice, involves the use of various products that may contain potential contact allergens. There is limited literature discussing ACD to hair removal products. We aim to discover the most common allergens prevalent in depilatory waxing products used in a popular wax center in the United States and those found in online marketplaces. Through communication with the salon staff, we reviewed the involved products and analyzed all ingredients for common allergens. We also conducted an online search to examine the ingredients and the most common allergens of the top 10 bestselling wax strips across four selected online marketplaces (CVS, Amazon, Walmart, and Walgreens). The final query of online products consisted of 12 distinct wax products and 10 postwax products. Among the products used in the salon, the most common allergens were vitamin E, colophony, botanicals, fragrance, beeswax/propolis, and color additives, in descending order. The most frequent allergens commonly encountered in online wax products included color additives, found in 67% (8/12) products, followed by botanicals and colophony, both present in 58% (7/12) products. In the postwax products, the most frequent allergen was vitamin E present in 100% (10/10) of the products, followed by fragrance (8/10). Although these allergens do not frequently cause ACD, it remains crucial to identify and note them in hair removal products to address any potential cases. Raising awareness of these allergens in all steps of hair removal can help ensure the safety and comfort of patients undergoing waxing treatments.

Comparison between mycobiota diversity and fungi and mycotoxin contamination of maize and wheat

Abstract The aim of this study was to establish the differences in fungi and mycotoxin contamination and mycobiota biodiversity between wheat and maize after harvesting. Determination of fungal contamination of wheat and maize is crucial, given that these grains are extensively used in food and feed production. Some moulds can produce toxic secondary metabolites, such as mycotoxins, which can cause serious health problems in humans and animals. Due to the metabolic activities of moulds, undesirable changes in food and feed colour, taste, and smell can occur. In this study, samples of wheat and maize, harvested during 2021 in the Northern Croatia, were analysed for mycological and mycotoxin contamination before storage. Also, potentially mycotoxigenic mould genera were identified at the species level in order to uncover the presence of toxigenic species. The presence of the following mycotoxins was examined: zearalenone, deoxynivalenol, ochratoxin, aflatoxin B1, T-2, and HT-2 toxin. The results indicate that both wheat and maize samples were contaminated with yeasts, with maize exhibiting a higher level of contamination as compared to wheat (1.5 × 104 to 1.8 × 106 vs 1.7 × 103 to 9.0 × 105). In wheat, the predominant mycotoxigenic mould species was Alternaria, as opposed to maize in which the Penicillium genus was the most represented. Mycotoxin analysis revealed that both maize and wheat were contaminated with Fusarium mycotoxins. Aflatoxin B1 and ochratoxin were not determined in any of the tested samples. The results point out that grains carry a different risk of contamination with Fusarium mycotoxins and that maize is more susceptible to fungus spoilage.

Nanoscale Zr(IV) MOF-Embedded Chitosan on Paper Composite for Aqueous Phase Detection of the Herbicide Metamitron and the Food Colorant Tartrazine

Nanoscale Zr(IV) MOF-Embedded Chitosan on Paper Composite for Aqueous Phase Detection of the Herbicide Metamitron and the Food Colorant Tartrazine

Development of an external standard method for the high-throughput determination of broadly polar multiclass synthetic dyes in high-sugar, high-fat, and high-protein foods

Simultaneous detection of multiple synthetic dyes in food additives presents a challenge. A high-throughput UPLC-Q-OMS method with purification-free extraction was developed for the simultaneous detection of 30 synthetic dyes across six categories in various foods. The results showed satisfactory separation of the dyes was achieved using a phenyl column, acetonitrile, and a 5 mmol/L ammonium acetate mobile phase. Designing methanol-acetonitrile (2:3, v/v) as a bifunctional extractant can minimize matrix interference and enhance synergistic effects. The LODs of the method were in the range of 0.15–6.28 μg/L, the LOQs were in the range of 0.48–20.52 μg/L with good linearity, and the correlation coefficients (r2) were greater than 0.99. The recoveries at the three spiked levels were in the range of 82.6 %–106.3 %. The technique detected four synthetic dyes within regulatory limits in six out of 66 sample batches (9.09 %), demonstrating its effectiveness in addressing interference and strong applicability.

Emissive glutathione modified sulphur quantum dots for the sensing of lemon yellow and luminescent hydrogels/films

Lemon yellow (LY) is an azo dye which is widely used as food colorant. The continuous consumption can result in the safety concerns for both human and environmental health. This study describes a new sulphur quantum dot (SQD) based fluorescent sensor, which was facilely prepared with oxidized-glutathione (GSSG) as passivator at mild condition of 75 °C. The obtained sulphur quantum dots (GSSG-SQDs) have a relative quantum yield of 0.25, which is 2–5 times that of most SQDs. GSSG-SQDs were used as a sensor for lemon yellow in the concentration range of 0.10–70 μM and the limit of detection of 60 nM. The application was verified with the real sensing of lemon yellow in the soft drinking and tap water, having the standard recovery from 92.5 % to 105 %. Given the great luminescence and photostability, GSSG-SQDs were used as a filler for the preparation of luminescent films and hydrogels as a promising material for a wide range of applications such as information encryption and bioengineering.

Eco-friendly property modulation of biobased gels of carboxymethyl cellulose-integrated poly(tertiary amine)s for the removal of azo-food dyes

Anionic polysaccharide-based gels enable the design of biobased materials with biochemical properties, non-toxic and natural origin. A new set of cationic gels was prepared from carboxymethylcellulose (CMC)-doped tertiary amino functional cationic monomers 2-(dimethylamino)ethyl methacrylate and N-(3-(dimethylamino)propyl) methacrylamide via the formation of semi-interpenetrated network (semi-IPN) at different polymerization temperatures, Tprep. A detailed understanding of the temperature-dependent synthesis and physicochemical response is required for the design of interpenetrating networks with CMC as an adsorbent that provides effective sources for the removal of azo-food dyes such as tartrazine and carmoisine from aqueous solutions. The variation of elasticity and swelling properties with respect to polymerization temperature was investigated. CMC-integration and polymerization temperature played a decisive role in the compressive elasticity. Incorporation of CMC into copolymer matrix led to a significant increase in elasticity of semi-IPNs, while mechanically weaker gels were obtained with increasing Tprep. Addition of CMC increased the swelling modulus of semi-IPNs formed at −18 °C by 2.6-fold. While the transparency changed depending on Tprep and microstructure, addition of CMC decreased the swelling rate of gels at all polymerization temperatures. The compressive modulus decreased with the swelling process in accordance with the Rubber elasticity theory. Semi-IPN gels showed stable swelling against pH-change in aqueous solutions and exhibited excellent pH-sensitivity significantly in low pH. A 4 to 12 fold decrease in maximum volume was observed by varying the pH between 2.1 and 9.8. The correlation between polymerization temperature and removal of azo-food dyes; tartrazine and carmoisine from contaminated wastewater with CMC-based gels was studied. Dynamic adsorption equilibrium was reached in 30 min, and tartrazine and carmoisine removal performances varied between 92.8 % and 98.4 %. respectively. The adsorption data for azo-dyes were evaluated by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Patterson, Sips, and Tooth isotherm models, but were best described by Langmuir and Redlich-Patterson models as they gave the highest correlation. Pseudo-first order, pseudo-second order, Elovich, Avrami kinetic and intra-particle diffusion models were investigated and dye adsorption was represented by pseudo-second-order model. After the adsorption process, semi-IPNs can easily be regenerated and effectively reused over five cycles. The study provided new insights towards the facile and sustainable synthesis of eco-friendly multifunctional CMC-based gels carrying tertiary amino groups for effective removal of azo-based food colorants.

STUDY ON THE UV-VIS SPECTROSCOPIC PROPERTIES OF SUDAN III AND SUDAN IV DYES IN DIFFERENT ORGANIC SOLVENTS

Uv/vis spectroscopy is a simple, low cost technique that can be used to identify and quantify adultrants such as azo dyes in foods. In this study, the ultraviolet-visible absorption spectral properties of Sudan III and Sudan IV dyes in non-polar solvent hexane, moderately polar solvent acetonitrile, and highly polar solvent ethanol were investigated using UV-VIS spectrophotometry. The results showed that the absorption peaks of Sudan III dye in hexane, acetonitrile and ethanol were within wavelenth ranges of 254-362 nm, 264-364 nm and 258-348 nm respectively, while the absorption peaks of Sudan IV dye in hexane, acetonitrile and ethanol were within the wavelenth ranges of 256-345nm, 262-367nm and 275- 369nm respectively, with the dyes absorbing maximally within the ultra violent region of the electromagnetic spectrum. This study will be very useful to the food scientists as it will assist in determining the appropriate wavelength for measuring/quantifying sudan lll and sudan IV dyes in food as the trend of azo dye adulteration of food such as palm oil is now rampant and has become one of the major challenges of food safety.

Role of chemistry in modern world: Boons and banes of chemical coating effects on human health

Water is the principal component of fresh fruits and Vegetable which constitutes between 80 to 90% of a produce's fresh weight. Fruits are covered by a layer of natural wax which acts as a barrier to reduce moisture loss and at the same times give the fruit a shiny surface. Besides orange shellac, other common materials used for these purposes include starch, carrageenan, alginates, wood rosin and various waxes. Panko breadcrumbs are crucial to the vegetables being very crispy. The coatings are typically made from natural materials, such as CHI, cellulose, and pectin that are safe for human consumption. The multilayer coating method has been shown to be effective in extending the shelf life of a variety of fresh fruits and vegetables, including apples, strawberries, tomatoes, and cucumbers. Both natural waxes (carnauba, shellac, beeswax or resin) and petroleum-based waxes (usually proprietary formulae) are used, and often more than one wax is combined to create the desired properties for the fruit or vegetable being treated. However, chemical treatments, such as copper sulfate, rhodamine oxide, malachite green, and deadly carbide, used on green vegetables to enhance coloration and freshness, are often counterproductive to their nutritional value. There is multiple health risks associated with these chemicals. This study reveals that food preservatives have made a big difference in eating food every day. They help keep the food safe because they add these chemicals to prevent spoilage and retard prevent or control undesirable changes in flavor, color, texture, or consistency of food and nutritive value of food which means the Control natural spoilage of food.

Solar Light Elimination of Bacteria, Yeast and Organic Pollutants by Effective Photocatalysts Based on Ag/Cr-TiO2 and Pd/Cr-TiO2

This study focused on searching for more effective nanomaterials for environmental remediation and health protection; thus, coliform bacteria, yeast and the organic food dye sunset yellow were selected as target pollutants to be eliminated under solar light by Ag/Cr-TiO2 and Pd/Cr-TiO2. Firstly, Cr3+ was in situ incorporated into the anatase crystalline lattice by the sol-gel method; then, Ag or Pd nanoparticles were deposited on Cr-TiO2 by chemical photoreduction. The scientific challenge addressed by the development of these composites was to analyse the recovery of Cr, to be employed in photocatalyst formulation and the enhancement of the TiO2 photocatalytic activity by addition of other noble metals. By extensive characterization, it was found that after TiO2 doping with chromium, the parameters of the crystal lattice slightly increased, due to the incorporation of Cr ions into the lattice. The TiO2 band gap decreased after Cr addition, but an increase in the optical absorptions towards the visible region after noble metals deposition was also observed, which was dependent of the Ag or Pd loading. Generally, it was observed that the noble metals type is a factor that strongly influenced the effectiveness of the photocatalysts concerning each substrate studied. Thus, by using Ag(0.1%)/Cr-TiO2, the complete elimination of E. coli from samples of water coming from a highly polluted river was achieved. Pd(0.5%)/Cr-TiO2 showed the highest efficiency in the elimination of S. cerevisiae from a lab prepared strain. On the other hand, the Pd(0.1%)/Cr-TiO2 sample shows the highest dye degradation rate, achieving 92% of TOC removal after 180 min.

Effect of Cooking Method on The Physicochemical Properties of Tomatoes

The cooking process influences the chemical and physical changes in food due to the increase in temperature. It also alters the appearance, taste, color, and texture of food either positively or negatively. Therefore, this study was done to determine the effect of cooking methods on the physicochemical properties and the retention of antioxidant content in tomatoes. The cooking conditions used were boiling at 100°C for 6 min, frying at 230°C for 4.5 min, baking at 175°C for 25 min, and cooking with an air fryer at 200°C for 15 min. Physicochemical characteristics (cooking loss, ash, crude fiber, firmness, color, pH value & total soluble solids) were measured. Antioxidant properties (antioxidant activity, total phenolic content, lycopene content, and ascorbic acid content) were also determined. There were significant differences (p<0.05) for ash, color, pH value, and total soluble solid, while no significant difference (p>0.05) was observed for cooking loss, crude fiber, and firmness. Different cooking methods had shown a significant difference (p<0.05) against all tests for determining antioxidant activity, total phenolic content, lycopene content, and ascorbic acid content. Air frying is the best cooking method to preserve the physicochemical properties of tomatoes, compared to other methods employed. Hence, it can be concluded that different cooking methods have different effects on the physicochemical properties of tomatoes.

Recent Advancements in Production and Extraction Methods of Phycobiliprotein C-phycocyanin by Arthrospira (Spirulina) platensis: A Mini Review.

Arthrospira platensis has been utilized as a food source since ancient times due to its rich nutrient profile. In recent years, its popularity as a dietary supplement has soared, especially due to the presence of a water-soluble phycobiliprotein, C-phycocyanin C (C-PC), which is abundant and notable for its fluorescent properties. C-PC contains the chromophore phycocyanobilin B (PCB-B), a tetrapyrrole molecule, that is why it plays a dual role as a food colorant and as nutraceutical. However, comprehensive studies have mostly evaluated C-PC's broader health-promoting properties, particularly its antioxidative and anti-inflammatory effects, which are linked to its ability to contrast oxidative stress and related pathological conditions. That is why this review explores recent advancements in optimizing culture conditions to enhance C-PC and PCB-B production, with a particular emphasis on novel extraction and purification techniques that increase yield and bioactivity. This focus on efficient production methods is crucial for expanding the commercial and therapeutic applications of C-PC, contributing to its growing relevance in the food and pharmaceutical industries.

Understanding the Molecular Interactions Between Pandan Pigment and Food Components for Enhanced Thermal Stability

Pandan pigment (Pandanus amaryllifolius) is widely used as a natural food coloring and flavoring agent. However, its application in food is limited because of its susceptibility to thermal degradation during food processing, which affects both pigment stability and color. Despite its growing use, there is limited research on how common food ingredients can mitigate this degradation. This study addresses this gap by exploring the effects of sucrose, lactose, rice starch, whey protein, and soy protein isolate on the thermal and color stability of pandan pigment under various heating conditions (65 °C, 95 °C, 115 °C, and 121 °C for 15 min). Spectroscopic techniques (UV–visible, infrared, and fluorescence) and laser confocal microscopy were used to elucidate the molecular interactions. The results revealed that rice starch provided the strongest protection, followed by whey protein, soy protein isolate, lactose, and sucrose, although the protective effects decreased at higher temperatures. These findings offer new insights into the use of sugars and proteins to increase the thermal stability of natural pigments in food applications.

Cultural Perspectives on the Sustainable Use and Added Value of Plant-Based Food Dyes—A Case Study from Bulgaria

Raised personal health awareness and social environmental responsibility put pressure on the agri-food industry to adopt more sustainable ways of production, including the use of more natural ingredients, reducing waste, conservation and the regeneration of resources and energy. Plant-based colorants are ecologically friendly alternatives to artificial food dyes, especially with regards to the current reports on the adverse effects of some of the latter on human health. Various plants are traditionally used by many cultures to obtain vivid food coloration; however, the knowledge and means to produce them becomes less and less accessible to urbanized societies, and affordable organic alternatives are not always available on the market. An online questionnaire was performed to explore the awareness on plant-based dyes and pro-environmental attitudes of Bulgarian customers through the lens of Orthodox Easter eggs dyeing and the obtaining of plant dyes. From a total of 294 adult participants, only 5% reported a strict preference for natural dyes, while more than half of them (54%) were found to use natural and artificial ones concomitantly or switching between both. Of 45 plant taxa used for egg coloration, 12 were most frequently cited with many new additions of imported plants. Most of the used plant-based dyes were common fruits, spices, herbal infusions and even food waste like onion peels and avocado pits that were readily available from home gardens, markets and food shops. Additionally, we made a review of the scientific literature regarding their antioxidant and antimicrobial activity against food spoilage bacteria and foodborne pathogens isolated from eggs. All frequently used taxa were reported to exhibit antibacterial activities against Gram-positive and Gram-negative bacteria and possess antioxidant activity due to the presence of various polyphenols, essential oils and other compounds. Grape and red wine, roselle and stinging nettle are the species with the most diverse antibacterial activity, effective against 15 out of the 16 bacterial species of spoilage and foodbourn microorganisms included in our focus. The antimicrobial activities, however, were found mostly tested against bacterial strains in vitro, and further studies are needed to confirm their potential antibacterial activity when applied to Easter/boiled eggs or other food products. Our findings suggest that traditional cultural practices, as a multifaceted and engaging phenomenon, have the potential to promote environmental responsibility and a healthy lifestyle using both contemporary and traditional knowledge.

A study on the effectiveness of (+)-usnic acid as oral toxic sugar bait against adult male and female Anopheles gambiae

BackgroundDespite the application of various tools for the control of vectors of Plasmodium falciparum, malaria remains the major killer disease in sub-Saharan Africa accounting for up to 90% of deaths due to the disease. Due to limitations of the useage of chemical insecticides such as resistance, negative impact on the environment and to nontarget organisms, the World Health Organization (WHO) requires that affected countries find alternative vector control tools. This study evaluated the effectiveness of ( +)-usnic acid (UA) as an insecticide through oral administration to male and female Anopheles gambiae as an alternative or additional active ingredient to be used in toxic sugar bait.Methods( +)-usnic acid was diluted using acetone at 5, 10, and 15 mg/ml concentrations in three replicates. A 5 ml mixture of 2% food dye and 10% sugar using chlorine-free water mixed with the dilutions of the ( +)-usnic acid and negative control was made containing 2% food dye and 10% sugar solution. The preparations were soaked on a ball of cotton wool and placed over the net of a cup. 5 male and 5 non-blood-fed female newly hatched starved An. gambiae Kisumu strain were introduced together into a cup and monitored for knockdown and mortalities after 4, 24 48, and 72 h. The data were analysed using a multiple linear regression model using the lm function, a base R function and a posthoc test were conducted on the significant main effects and interaction terms using the emmeans function from the emmeans R package. All analyses were performed in RStudio using base R (version 4.3.3).ResultsThere was high mortality of both male and female An. gambiae after ingestion of the toxic sugar bait. 15 mg/ml usnic acid caused the highest mortality (50%) within the first 4 h compared to 5 and 10 mg/ml ( +)-UA. There was a decline in the mortality rate with increased exposure time from 24 to 72 h, however, there was a significant difference in mortality at 5, 10 and 15 mg/ml. Acute toxicity was associated with ingestion of 15 mg/ml after 24 h. 72 h post-mortality was lower in all concentrations than in the control. High mortality was observed among females over the first 4 h (60%) compared to males (40%) due to higher feeding rate of the toxic agent. The proportion of dead males and females was equal after 24 h while after 48 h, the proportion of dead males was high.There was a significantly lower mortality rate after 72 h for both males and females (0 to 13.3%). Compared to all the treatments, high mortality of males was observed.ConclusionsThe results of this study indicate that ( +)-UA when administered as oral sugar bait to An. gambiae has insecticidal properties and is a suitable ingredient to be used as a toxic agent in the novel attractive toxic sugar bait for the control of malaria vectors. ( +)-UA may be an alternative active ingredient as toxic bait in the effort to reduce and eliminate the transmission of Plasmodium falciparum in Africa.

Gastrointestinal toxicity following sub-acute exposure of erythrosine in rats: biochemical, oxidative stress, DNA damage and histopathological studies.

Erythrosine, a synthetic food dye, has been controversial due to its potential health risks. This study examines the effect of erythrosine on activity of antioxidative enzymes, oxidative stress indices, DNA damage through comet assay, and histopathological changes on stomach, intestine, and colon over a period of 28 days in rats. Twenty-four rats were randomly divided into four groups (n = 6). The first is the control group and then one each for three doses of erythrosine based on acceptable daily intake (¼ ADI, ½ ADI, and ADI, 0.1 mg/kg body weight). The results revealed that with increasing dosages the activity of catalase decreased in stomach and intestine but in colon, the catalase activity increased. Superoxide dismutase and glutathione-S-transferase activity decreased in dose-dependent manner in all three tissues. While, in stomach and intestine, the acetylcholinesterase activity showed increment in ¼ ADI dose group and then declined in ½ ADI and ADI dose-administered rats. The oxidative stress indicators showed elevated levels of lipid peroxidation, hydrogen peroxide concentration, and lactate dehydrogenase activity suggesting heightened free radical activity and potential oxidative damage. The comet test was used to evaluate DNA damage, revealing substantial damage in the erythrosine administered groups. Histopathological examination showed inflammatory infiltration and other degenerative changes in gastrointestinal tract, highlighting the dye's adverse effects. The research underscores the need for a comprehensive reevaluation of the safety and toxicity of food dyes like erythrosine, especially considering the inconsistencies in existing studies regarding the dye's safety.

Screening of Antioxidant Maillard Reaction Products Using HPLC-HRMS and Study of Reaction Conditions for Their Production as Food Preservatives

The Maillard reaction (MR) involves interactions between reducing sugars and amino acids or proteins during heating, producing Maillard reaction products (MRPs) that influence food flavour, aroma, and colour. Some MRPs exhibit antioxidant properties, prompting interest in their potential as natural food preservatives. This study aimed to develop a method for detecting and identifying antioxidant MRPs using high-pressure liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (HRMS). By improving chromatographic conditions, the separation of antioxidant MRPs was optimised using known antioxidant MRPs as reference signals. This work also examined the effects of pH, reaction time, and different sugar–amino acid combinations on the production and composition of antioxidant MRPs. Results indicated that neutral to basic pH facilitated faster reactions, with pH 7 selected as optimal. A library of 50 m/z signals for potential antioxidant MRPs was created, and the best combinations of amino acids and sugars for their production were identified. These findings pave the way for more precise analyses of antioxidant MRPs, with future research focusing on isolating and characterising specific MRPs to understand their structures and mechanisms, ultimately contributing to the development of functional foods with natural antioxidant properties.