Evaluation of the DNA damaging effect of the heat-induced food toxicant 5-hydroxymethylfurfural (HMF) in various cell lines with different activities of sulfotransferases

The antisickling agent, 5-hydroxymethyl-2-furfural: Other potential pharmacological applications

For the last two decades, the aromatic aldehyde 5-hydroxymethyl-furfural (5-HMF) has been the subject of several investigations for its pharmacologic potential. In 2004, the Safo group reported that 5-HMF has potent antisickling activity by targeting and ameliorating the primary pathophysiology of hypoxia-induced sickling of erythrocytes (red blood cells [RBC]). Following the encouraging outcome of the preclinical and phase I/II clinical studies of 5-HMF for the treatment of sickle cell disease (SCD), there have been multiple studies suggesting 5-HMF has several other biological or pharmacologic activities, including anti-allergic, antioxidant, anti-hypoxic, anti-ischemic, cognitive improvement, anti-tyrosinase, anti-proliferation, cytoprotective, and anti-inflammatory activities. The wide range of its effects makes 5-HMF a potential candidate for treating a variety of diseases including cognitive disorders, gout, allergic disorders, anemia, hypoxia, cancers, ischemia, hemorrhagic shock, liver fibrosis, and oxidative injury. Several of these therapeutic claims are currently under investigation and, while promising, vary in terms of the strength of their evidence. This review presents the research regarding the therapeutic potential of 5-HMF in addition to its sources, physicochemical properties, safety, absorption, distribution, metabolism, and excretion (ADME) profiles.

Influence of heat treatments on the functionality of soy protein hydrolysates in animal cell cultures

Soy protein hydrolysates enhance integral viable cell density (IVCD) and recombinant protein production (Immunoglobulin, IgG) in cell cultures, but their functionality varies from batch-to-batch. This is undesirable since it affects both quantity and characteristics of the recombinant proteins. It is hypothesized that the variability of hydrolysates is due to variations in meal and hydrolysate processing treatments. To study this, hydrolysates were produced from meals heated at 121 °C/0-120 min. The heating decreased free amino acid and reducing monosaccharide contents in meals (0.72-0.27% and 3.3-2.6%) and hydrolysates (14.7-7.1% and 16.9-7.9%). Dry heating introduced large variation in the IVCD ((115-316%), but additional heating in suspension reduced it (131-159%). The decrease in IVCD variation corresponded with decreased variation in carboxymethyl-lysine (CML) and lysinoalanine (LAL) contents. Thus, meal and hydrolysate processing induced substantial variation in hydrolysate functionality. It is therefore critical to establish strict process controls for meal and hydrolysate production to ensure consistency.

Reducing the Risk of Acrylamide and Other Processing Contaminant Formation in Wheat Products

Wheat is a staple crop, consumed worldwide as a major source of starch and protein. Global intake of wheat has increased in recent years, and overall, wheat is considered to be a healthy food, particularly when products are made from whole grains. However, wheat is almost invariably processed before it is consumed, usually via baking and/or toasting, and this can lead to the formation of toxic processing contaminants, including acrylamide, 5-hydroxymethylfurfural (HMF) and polycyclic aromatic hydrocarbons (PAHs). Acrylamide is principally formed from free (soluble, non-protein) asparagine and reducing sugars (glucose, fructose and maltose) within the Maillard reaction and is classified as a Group 2A carcinogen (probably carcinogenic to humans). It also has neurotoxic and developmental effects at high doses. HMF is also generated within the Maillard reaction but can also be formed via the dehydration of fructose or caramelisation. It is frequently found in bread, biscuits, cookies, and cakes. Its molecular structure points to genotoxicity and carcinogenic risks. PAHs are a large class of chemical compounds, many of which are genotoxic, mutagenic, teratogenic and carcinogenic. They are mostly formed during frying, baking and grilling due to incomplete combustion of organic matter. Production of these processing contaminants can be reduced with changes in recipe and processing parameters, along with effective quality control measures. However, in the case of acrylamide and HMF, their formation is also highly dependent on the concentrations of precursors in the grain. Here, we review the synthesis of these contaminants, factors impacting their production and the mitigation measures that can be taken to reduce their formation in wheat products, focusing on the role of genetics and agronomy. We also review the risk management measures adopted by food safety authorities around the world.

Selection of a Novel DNA Aptamer Specific for 5-Hydroxymethylfurfural Using Capture-SELEX

A capture systematic evolution of ligands by exponential enrichment (Capture-SELEX) was described to discover novel aptamers specific for 5-hydroxymethylfurfural (5-HMF), and a biosensor based on molecular beacon was constructed to detect 5-HMF. The ssDNA library was immobilized to streptavidin (SA) resin to select the specific aptamer. The selection progress was monitored using real-time quantitative PCR (Q-PCR), and the enriched library was sequenced by high-throughput sequencing (HTS). Candidate and mutant aptamers were selected and identified by Isothermal Titration Calorimetry (ITC). The FAM-aptamer and BHQ1-cDNA were designed as the quenching biosensor to detect 5-HMF in milk matrix. After the 18th round selection, the Ct value decreased from 9.09 to 8.79, indicating that the library was enriched. The HTS results indicated that the total sequence numbers for 9th, 13th, 16th, and 18th were 417054, 407987, 307666, and 259867, but the number of sequences for the top 300 sequences was gradually increased from 9th to 18th, and the ClustalX2 analysis showed that there were four families with high homology rate. ITC results indicated that the K_d values of H1 and its mutants H1-8, H1-12, H1-14, and H1-21 were 2.5 μM, 1.8 μM, 1.2 μM, 6.5 μM, and 4.7 μM. The linear range of the quenching biosensor was from 0 μM to 75 μM, and it had a similar linear range in the 0.1% milk matrix. This is the first report to select a novel aptamer specific for 5-HMF and develop quenching biosensor for the rapid detection of 5-HMF in milk matrix.

Compound Identification from Bromelia karatas Fruit Juice Using Gas Chromatography–Mass Spectrometry and Evaluation of the Bactericidal Activity of the Extract

Fruits of species of the genus Bromelia contain compounds with health benefits and potential biotechnological applications. For example, Bromelia karatas fruits contain antioxidants and proteins with bactericidal activity, but studies regarding the activity of these metabolites and potential benefits are required. We evaluated the bactericidal activity of the methanolic extract (treated and not treated with activated charcoal) and its fractions (hexane, ethyl acetate, and methanol) from ripe B. karatas fruit (8 °Brix) against Escherichia coli, Enterococcus faecalis, Salmonella enteritidis, and Shigella flexneri. The methanolic extract (ME) minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at eight concentrations. The methanolic extract MIC was 5 mg/mL for E. faecalis and 10 mg/mL for the other bacteria; the MBC was 20 mg/mL for E. coli and E. faecalis, and 40 mg/mL for S. enteritidis and S. flexneri. Through gas chromatography–mass spectrometry, 131 compounds were identified, some of which had previously been reported to have biological activities, such as bactericidal, fungicide, anticancer, anti-inflammatory, enzyme inhibiting, and anti-allergic properties. The most abundant compounds found in the ME of B. karatas fruits were maleic anhydride, 5-hydroxymethylfurfural, and itaconic anhydride. This study shows that B. karatas fruits contain metabolites that are potentially beneficial for health.

Comparison of the Effects of 5-Hydroxymethylfurfural in Milk Powder Matrix and Standard Water on Oxidative Stress System of Zebrafish

5-Hydroxymethylfurfural (5-HMF) and furfural (FF) are products of the maillard reaction (MR) in milk powder and their safety is controversial. The concentration changes of 5-HMF and FF after a period of cold storage were determined by high-performance liquid chromatography (HPLC). Then, we compared the toxicity effects of 5-HMF (2, 20, or 200 μM) in milk powder matrix and standard water on the oxidative stress system of zebrafish embryos. The results showed that the concentration of 5-HMF was stable, and the concentration of FF degraded over time. 5-HMF-exposed zebrafish embryos had a LC₅₀ value of 961 μM for 120 h. High-concentration of 5-HMF exposure resulted in developmental toxicity and induced oxidative stress. 5-HMF exposure resulted in low expression of gstr gene at 200 μM in both matrices. Moreover, sod, cat, gstr, and gpxla genes were differentially highly expressed in other groups or showed no significant difference. Residual levels in all groups were well below the exposed dose, with a maximum value of only 0.4‱. These results provided a theoretical basis for understanding the effects of 5-HMF exposure in milk powder matrix on the oxidative stress system and suggested that the presence of 5-HMF in our daily consumption of milk powder does not produce significant toxic effects and need not be overstressed.

A systematic review on botany, processing, application, phytochemistry and pharmacological action of Radix Rehmnniae

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Rehmanniae (RR) is the tuber root of Rehmannia glutionsa Libosch, which was firstly recorded in Shennong's Classic of Materia Medica (⟪⟫). RR is a non-toxic and wide used traditional Chinese medicine. RR has the effect of clearing heat, generating essence, cooling blood, stopping bleeding, nourishing yin and blood, and filling marrow. It is used in clinic in the form of processed decoction pieces, including Dry Radix Rehmnniae (DRR) and Rehmanniae Radix Praeparata (RRP). The application of RR in traditional Chinese medicine (TCM) prescriptions can treat various diseases, such as anemia, irregular menstruation, deficiency of liver yin, renal failure and so on.

AIM OF REVIEW

This paper aims to provide a comprehensive and productive review of RR, which mainly contains botanical characteristics, processing methods, traditional application, chemical composition, quality control and pharmacological action.

MATERIALS AND METHODS

Literature search was conducted through the Web of Science, Baidu Scholar, ScienceDirect, PubMed, CNKI, and WanFang DATA using the keywords "Radix Rehmnniae", "Rehmanniae Radix Praeparata", "processing", "clinical application", "chemical composition", "quality control", and "pharmacological action". In addition, information was collected from relevant textbooks, reviews, and documents.

RESULTS

RR is a traditional Chinese herbal medicine with clinical value and rich resources. More than 100 components have been isolated and identified from RR. It has multiple pharmacological actions, such as hemostasis, antioxidation, anti-osteoporosis, lowering blood sugar, improving renal function, anti-inflammation, protecting neuronal function, antidepression and anti-anxiety. DRR and RRP are two different processed products of RR. After processing, there are great changes in property, taste, efficacy, clinical application, chemical composition and pharmacological action. At present, identifying chemical constituents of RR and its medicinal value has been deeply studied. However, there is a lack of research on the reasons for the differences in pharmacological effects between DRR and RRP. The reasons for these differences need to be further verified. Catalpol, the active component of RR, has been studied extensively in the literature, but the pharmacological effects of catalpol cannot represent the pharmacological effects of the whole RR. In the future, effective components such as rehmannioside D, polysaccharide, total glycosides, and effective parts in RR need to be further studied and developed. The pharmacodynamic material basis and mechanism of RR need to be further discussed. The scientific connotation and processing methods of RRP need to be studied and standardized.

Effects of Light Exposure, Bottle Colour and Storage Temperature on the Quality of Malvasia delle Lipari Sweet Wine

The influence of light exposure, bottle color and storage temperature on the quality parameters of Malvasia delle Lipari (MdL) sweet wine were investigated. Wine samples bottled in clear-colored (colorless, green and amber) glass were stored under different artificial lighting conditions, in order to simulate the retail environment (one cool-white, fluorescent lamp) and to perform an accelerated test (four and six cool-white, fluorescent lamps). The storage temperature was kept constant (25 °C) for the first 90 days of the experiment and then samples were monitored for up to 180 days at higher temperatures (30, 35 and 40 °C). The principal enological parameters, total phenols, color, 5-hydroxymethylfurfural (HMF) and 2-furaldehyde (2F) contents were studied. The shelf-life test pointed out minimum variations of the basic chemical parameters, while the quality attributes most affected by lighting were color, together with HMF and 2F levels which, hence, can be considered as indicators of the severity of storage conditions.

Fast Detection of 5-Hydroxymethylfurfural in Dulce de Leche by SPE-LC–MS

This research paper investigates the use of 5-hydroxymethylfurfural (5-HMF) as marker for the heat treatment of spreadable dairy creams (dulce de leche, DL). The proposed method applies solid-phase extraction (SPE) with final analysis by liquid chromatography coupled with high-resolution mass spectrometry (SPE-LC–MS). The method was successfully applied to analyze spreadable dairy creams prepared by hot melt extrusion using different heating temperatures from 100 to 130 °C. The concentrations of 5-HMF correlated linearly with the applied temperatures, with a signal response in the range from 0.5 to 100 μM (R2 = 0.9997). The limit of detection (LOD) was 1.54 ± 0.03 µM with a precision of 1.77%. The results were compared with the analysis of 5-HMF in spreadable dairy creams using reference methods for the determination of 5-HMF in milk products. These methods mainly employed acid digestion and derivatization as pre-processing steps and determined 5-HMF spectrophotometrically and via HPLC–UV. These resulted in higher LOD (2.99 and 2.01 μΜ) and less precision (4.44 and 2.09%) compared to the proposed method. Furthermore, the proposed pre-processing procedure was faster by omitting the acid digestion and derivatization steps and by employing SPE.

Caramel colors in terms of scientific research, with particular consideration of their toxicity

Caramel colors, the most common food additives in the world, are divided into four classes (IIV), marked with the symbols E150 a-d, respectively. Individual classes of caramel colors differ from each other in physico-chemical properties and the method of preparation, which affects the formation of various compounds that are important for the assessment of food safety A number of studies on all caramel classes of have been performed, including toxicokinetic, genotoxic, carcinogenic and reproductive and developmental toxicity studies, which have not shown harmful effects of these additives at doses not exceeding ADI. However, there is an increasing number of scientific reports of the possible toxic effects present in caramels of low-molecular compounds. Currently, three compounds are considered to be toxicologically important and resulting from the possible concentration in the final product: 5-HMF (present in all classes), 4(5)-MeI (present in caramel classes III and IV) or THI (present in caramel class III). 4(5)-MeI has a neurotoxic effect and was considered in 2011 as a possible human carcinogen (class 2B, according to IARC). In the case of THI, studies have confirmed its lymphopenic activity, probably secondary to its immunosuppressive effect. Consequently, in the 1980s, JECFA set acceptable levels 4(5)-MeI and THI, for the caramel classes in which these compounds may be present. The toxicity of 5-HMF has not been confirmed unequivocally, but studies have shown that this compound is not neutral to living organisms. Currently, most international organizations and scientific institutes recognize these additives as safe for consumers, but at the same time scientists emphasize the need for further research.

Waterpipe smoke condensate influences epithelial to mesenchymal transition and interferes with the cytotoxic immune response in non-small cell lung cancer cell lines

Waterpipe tobacco smoking (WPS) continues to spread globally and presents serious health hazards. The aim of the present study was to investigate the effects of treatment with WPS condensate (WPSC) on lung cell proliferation and plasticity as well as tumor cell recognition and killing by natural killer (NK) cells using cytotoxicity assays. The results indicated that exposure of normal and cancer lung cell lines to WPSC resulted in a decrease in their in vitro growth in a dose-dependent manner and it induced tumor senescence. In addition, WPSC selectively caused DNA damage as revealed by an increase in γH2AX and 53BP1 in tumor lung cells. To gain further insight into the molecular mechanisms altered by WPSC, we conducted a global comprehensive transcriptome analysis of WPSC-treated tumor cells. Data analysis identified an expression profile of genes that best distinguished treated and non-treated cells involving several pathways. Of these pathways, we focused on those involved in epithelial to mesenchymal transition (EMT) and stemness. Results showed that WPSC induced an increase in SNAI2 expression associated with EMT, ACTA2 and SERPINE2 were involved in invasion and CD44 was associated with stemness. Furthermore, WPSC exposure increased the expression of inflammatory response genes including CASP1, IL1B, IL6 and CCL2. While immune synapse formation between NK and WPSC-treated lung cancer target cells was not affected, the capacity of NK cells to kill these target cells was reduced. The data reported in the present study are, to the best of our knowledge, the first in vitro demonstration of WPSC effects on lung cellular parameters providing evidence of its potential involvement in tumor physiology and development.

Determination of patulin and hydroxymethylfurfural in beverages by UPLC-PDA

The present study describes using molecularly imprinted polymer (MIP) technology for determination of patulin (PAT) and 5-hydroxymethylfurfural (5-HMF) in beverages by ultra-high performance liquid chromatography coupled to photodiode array (UPLC-PDA). PAT (4-hydroxy-4H-furo[3,2-c]pyran-2(6H)-one) is a mycotoxin produced by Penicillium fungi and Penicillium expansum is probably the most commonly encountered species that infects apples during their growth, harvest, storage or processing. The occurrence of PAT as a natural contaminant of apples is a worldwide problem. 5-HMF (also known as 5-(hydroxymethyl) furan-2-carbaldehyde), is formed in the Maillard reaction as well as during caramelisation. It is a good storage time-temperature marker and flavour indicator, especially in beverages such as wine, beer, but also cider and apple juice which may contain PAT. PAT and 5-HMF were separated within 2 min using a Luna Omega C18 column and the PDA detector wavelength was set to 276 nm. The validation parameters of the analytical method such as linearity, limit of detection, limit of quantification, accuracy and precision were tested. The calibration curves were linear at least in the range 50-1000 ng/ml with a good linearity (R2>0.999) for both analytes, the limit of detection and the limit of quantification for PAT and 5-HMF were in the range 4.9-6.6 and 16.1-21.8 μg/l, respectively. The recoveries of the selected analyte were in the range 61.9-109.0% with a precision of <8.2% (relative standard deviation (RSD)) for PAT and in the range 50.8-98.0% with a precision of <10.0% (RSD) for 5-HMF. The validated procedure was successfully applied for the analysis of PAT and 5-HMF in beverages from retail shops.

A New Enrichment Method for Quantification of 5-Hydroxymethylfurfural by Indirect Flame Atomic Absorption Spectrometry in Honey and Jam Samples

Background

Because of increasing amounts of 5-hydroxymethylfurfural (5-HMF) in processed foods and the complexity of the matrix, monitoring of trace 5-HMF requires accurate and reliable methods. Hence, an efficient sample pretreatment procedure is necessary for extraction and preconcentration of 5-HMF from the matrix.

Objective

In this study, a new and efficient sample preparation method utilizing ultrasound-assisted-cloud point extraction (UA-CPE), indirectly followed by flame atomic absorption spectrometry (FAAS), was introduced for the monitoring of trace amounts of 5-HMF in honey and jam samples.

Method

With this method, hydroxylamine was used as a derivatizing agent in the presence of Mn(II) and an anionic surfactant, SDS for extraction of 5-HMF at pH 9.0. For dispersing reagents in sample solution, low amounts of mixed surfactant, triton X-45 and SDS were mixed and fast-injected into the extraction media. A cloudy solution formed, and after reaction of 5-HMF with reagents, the cloudy solution was centrifuged. The extracted 5-HMF in the surfactant-rich phase was dissolved in acidic acetone and indirectly analyzed by FAAS.

Results

The method showed a detection limit of 1.27 μg/L in linear working range of 4–240 μg/L, good precision (2.3–6.5%), and recovery rates (93.5–97%) after preconcentration of 70-fold.

Conclusions

Within this study, an accurate and reliable method for the indirect quantification of 5-HMF in selected samples was successfully developed with a sensitivity improvement factor of 30.6.

Highlights

The figures of merit for the developed indirect method were appropriate. The applicability of the method for the analysis of 5-HMF in processed foods was excellent.

Optimization of the roasting conditions to lower acrylamide content and improve the nutrient composition and antioxidant properties of Coffea arabica

Roasting is the most common method of processing coffee. During roasting, aromatic compounds are generated due to various reactions, which are important for developing color, flavor and aroma. Acrylamide is an undesirable carcinogenic substance that is metabolically activated and formed during the coffee roasting process. Coffea arabica was first found in Ethiopia, and Ethiopia can produce a large volume of coffee. The major coffee-producing areas in Ethiopia are Hararghe, Sidama, Gimbi/Nekemte, Yergachefe and Limu. The primary purpose of this study was to quantify the acrylamide contents of brewed and roasted coffee collected from street coffee sellers and industrial processors found in Addis Ababa, Ethiopia, and optimize the roasting conditions for Sidama coffee. The acrylamide contents were determined by HPLC using a DAD at 210 nm, the antioxidant property were examined using a UV-spectrophotometer, and moisture and nutrient composition of coffee was determined using the method described by the AOAC (Association of Official Analytical Chemists). The roasting temperature and time were optimized based on the acrylamide content, nutritional composition and antioxidant property of the coffee using central composite design. The roasting temperature and time significantly affected (p<0.05) the acrylamide level, nutritional composition and antioxidant property of the coffee. The acrylamide contents of street and industrial processed powdered coffee were 346 ±19 to 701±38μg/kg and 442±14 to 906±7μg/kg, respectively. Brewed coffee from street vendors and industrial processing had acrylamide contents of 25±2 to 49±1μg/L and 63±2 to 89±4μg/L, respectively. The EC50 values for scavenging radicals for the optimized coffee ranged from 171±0 to 111±4 μg/L. The optimal roasting temperature and time were 190°C and 6 minutes, at this temperature and time the acrylamide content decreased, and the antioxidant and nutritional compositions of the coffee improved.

Potential neurotoxicity of 5-hydroxymethylfurfural and its oligomers: widespread substances in carbohydrate-containing foods

5-Hydroxymethylfurfural (5-HMF) is present in numerous carbohydrate-containing consumer products and is readily converted into two oligomers (II and III) by acid-catalyzed transformations. Previous studies have demonstrated various undesirable effects of 5-HMF at relatively high concentrations. In this study, we demonstrate that 5-HMF and its two oligomers exert neurotoxic effects in vivo and in vitro. All three substances blocked the proliferation of PC12 and HT22 cells at the S or G2-M phase in dose- and time-dependent manners. In addition, [Ca²⁺]i and reactive oxygen species levels were both significantly increased by treatment with these substances at 100 μM, individually, compared with the control group. Although no motor and cognitive deficits are observed, 5-HMF and III can induce anxiety- and depression-like behavior in adolescent mice at administered doses of 0.15 mg kg^-1 and 1.5 mg kg^-1in vivo, which are close to or less than the reported 24 h dietary intake of 5-HMF in humans. Together, our findings suggest the need for close monitoring of the content of these substances in food, as well as the need for studies on the effects of long-term exposure to them.

The Toxicological Aspects of the Heat-Borne Toxicant 5-Hydroxymethylfurfural in Animals: A Review

The incidence of adverse reactions in food is very low, however, some food products contain toxins formed naturally due to their handling, processing and storage conditions. 5-(Hydroxymethyl)-2-furfural (HMF) can be formed by hydrogenation of sugar substances in some of manufactured foodstuffs and honey under elevated temperatures and reduced pH conditions following Maillard reactions. In previous studies, it was found that HMF was responsible for harmful (mutagenic, genotoxic, cytotoxic and enzyme inhibitory) effects on human health. HMF occurs in a wide variety of food products like dried fruit, juice, caramel products, coffee, bakery, malt and vinegar. The formation of HMF is not only an indicator of food storage conditions and quality, but HMF could also be used as an indicator of the potential occurrence of contamination during heat-processing of some food products such as coffee, milk, honey and processed fruits. This review focuses on HMF formation and summarizes the adverse effects of HMF on human health.

Valorization of Yarrow (Achillea millefolium L.) By-Product through Application of Subcritical Water Extraction

In the present study, valorization of yarrow (Achillea millefolium) by-product from the filter tea industry was investigated through the application of subcritical water for the extraction of bioactive compounds. The influence of different process parameters (temperature 120-200 °C, extraction time 10-30 min, and HCl concentration in extraction solvent 0-1.5%) on extract quality in terms of content of bioactive compounds and antioxidant activity was investigated. Optimal conditions of the extraction process (temperature 198 °C, extraction time 16.5 min, and without acidifer) were determined and, when applied, the most efficient exploitation of by-products is achieved, that is, attainment of extracts rich in total phenols and flavonoids and high antioxidant activity. In addition, by applying the high performance liquid chromatographic analysis, the content of chlorogenic acid was determined as well as the hydroxymethylfurfural content in obtained extracts. The results demonstrated that subcritical water can be successfully used for utilization of yarrow by-products for obtaining extracts rich in antioxidants.

Extra virgin olive oil enhances the hepatic antioxidant defense and inhibits cytogenotoxic effects evoked by 5-hydroxymethylfurfural in mice

This study was performed to assess the ability of the food genotoxicant 5-hydroxymethylfurfural (5-HMF) to induce DNA damage and oxidative injuries in the liver of mice as a possible mechanism of toxic action and to evaluate the role of extra virgin olive oil (EVOO) in inhibiting these injuries. For this purpose, 80 mice were assigned into four equal groups of 20 mice each. Group 1 was kept as control and group 2 was given 5-HMF (250 mg/kg bw) by intraperitoneal (IP) injection 3 times weekly for 4 weeks. Group 3 received EVOO (300 μl/kg bw) orally daily for 4 weeks. Group 4 was co-treated with both 5-HMF (250 mg/kg bw) with IP injection and EVOO (300 μl/kg bw) orally 3 times weekly for 4 weeks. IP injection of 5-HMF resulted in a significant decrease in albumin, globulin, and total protein contents and significant increases in alanine transaminase, aspartate transaminase, and alkaline phosphatase activities. Administration of EVOO alone or with 5-HMF reduced the 5-HMF-induced alterations and restored the liver function biomarkers, antioxidant defense system, and histoarchitecture of the liver to normal values. EVOO also inhibited the genotoxic and apoptotic effects of 5-HMF suggesting that EVOO could provide liver protection through its powerful antioxidant and confirm its good nutriceutical and pharmacological properties.

Changes of 5-hydroxymethyl-2-furfural in fresh and processed ginsengs

The study estimated changes of 5-hydroxymethyl-2-furfuraldehyde (5-HMF) in different ginseng products with different temperatures and time pretreatment. Heat treatment was performed at various temperatures for 1.50, 2.00, 2.50, and 3.00 hr, respectively. Ultrasonic extraction and reflux extraction were used to evaluate the extraction rate and different solvents (such as 80% methanol, dichloromethane, ethyl acetate, and an extraction with both dichloromethane and ethyl acetate solvents) using two extraction methods (liquid-liquid extraction and solid-phase extraction) to remove matrix interference. An ultraperformance liquid chromatography-mass spectrometer (UPLC-MS) method was used for quantitative and changing analysis of 5-HMF in different ginseng samples. The results indicated that the content of 5-HMF increased dramatically with heating temperature and time, and the 5-HMF in the ginseng samples ranged from 0.01 to 112.32 g/kg protein. The highest value was observed in the honey-added ginseng samples with the highest amount of addition and highest temperature treatment, and the lowest value was found in the fresh ginseng samples. These results implied that 5-HMF may be as an indicator to estimate the honey addition level and heat treatment degree during the processing of ginseng products, and the content of 5-HMF is a promising parameter to evaluate the quality of products (ginseng). The production and regulation of potentially harmful Maillard reaction products (PHMRPs)-5-HMF in ginseng manufacture will provide an important reference for safe ginseng processing.

Influence of carbohydrate additives on 5-hydroxymethylfurfural (HMF) content in pork tenderloin

Heat-processed foodstuffs are a rich source of Maillard reaction products (MRPs) in the daily human diet. Although MRPs favourably affect the colour and flavour of heat-processed foods, they also have an impact on nutritional value and safety. Some MRPs (e.g. 5-hydroxymethylfurfural) may be toxic, mutagenic or carcinogenic and their presence in food has been studied extensively due to possible negative health effects(1,2). There is a general scarcity of published information on 5-hydroxymethylfurfural (HMF) concentrations in meat products.

This study analysed whether there are differences in the concentrations of HMF between smoked pork tenderloins previously cured with the addition of glucose, saccharose or maltodextrin at concentrations of 0.5, 1.0 or 1.5% (including the control trial without sugar). Material for the tenderloin production consisted of longissimus dorsi muscles collected from 20 porcine carcasses. Colour parameters of the external surface (CIE L*a*b* system) and the content of water and 5-hydroxymethylfurfural were determined. The HMF content was analysed with reversed-phase high-performance liquid chromatography (RP-HPLC).

The type of sugar used for curing had a significant impact on the amount of HMF formed in the product. The highest HMF content was found in the tenderloins cured with saccharose (it was about three-fold higher than the control trial and trials with glucose or maltodextrin). The formation of HMF was influenced not only by the type but also by the concentration of carbohydrates. Higher concentrations of glucose and maltodextrin resulted in a slight increase in the HMF content in the product (P > 0.05), while a higher concentration of saccharose produced a very pronounced HMF content increase (P < 0.05). Furthermore, tenderloins cured with a 2% carbohydrate addition were characterized by a lower water content (P < 0.01) and a darker surface colour (P < 0.01) compared to tenderloins with a lower carbohydrate addition. The results indicate the clear impact of technological additives on the HMF content of tenderloins. Conducting studies on the HMF in meat products is fully justified due to the relatively high HMF contents observed in the experiment (approximately 20–23 mg/kg), which were comparable to products such as bread or fruit jams.

Hydrothermal carbonization of sewage sludge: A critical analysis of process severity, hydrochar properties and environmental implications

Hydrothermal carbonization (HTC) of sewage sludge reduces the waste volume and can be source of energy and valuable products. Furthermore, HTC offers several advantages over conventional dry-thermal pre-treatments, as no prior drying is requested, and the high quality of the char produced promotes applications as energy production and storage, wastewater remediation, and soil amendment. Relationships between char yields, physicochemical properties and process parameters are here analysed, with the aim to provide insight into the choice of the process severity required to fit the desired application. Moreover, presence and fate of heavy metals and organic contaminants are discussed. The highest reaction temperature is the main parameter affecting the physicochemical characteristics of the char produced, while the heating rate governs the heat mass transfer and the rate of intermediates formation. Depolymerization of the biomass results in a reduction of the oxygen to carbon ratio and, therefore, in augmented high heating values, further increased by deposition of 5-(hydroxymethyl)furfural. Recirculation of process water may enhance dehydration reactions and the deposition of degraded polymers, increasing dewaterability and yield, but field trials are recommended to assess the feasibility of this option. An overuse of chars for energy generation purposes would be deleterious for the environmental life cycle. Further research is encouraged to assess the pollutants abatement and their degradation pathways when incorporated in the carbonaceous product, to promote the application of hydrochars as soil amendment, as well as for environmental remediation purposes.

Chemical defense responses of upland cotton, Gossypium hirsutum L. to physical wounding

Upland cotton (Gossypium hirsutum L.) produces terpenoid aldehydes (TAs) that protect the plant from microbial and insect infestations. Foliar TAs include plus (+)- and minus (-)-gossypol, hemigossypolone, and heliocides. To examine foliar TAs' response to physical wounding, the four TA derivatives of a fully glanded G. hirsutum variety JACO GL were quantified by ultra-high performance liquid chromatography. The results show that foliar heliocides increased by 1.7-fold in younger leaves after wounding. While the hemigossypolone level was not affected by the physical wounding, the level of heliocides was significantly increased up to 1.8-fold in the younger leaves. Upland cotton accumulates concentrated carbohydrates, amino acids, and fatty acids in foliar extrafloral nectar (EFN) to serve as a nutrient resource, which attracts both beneficial insects and damaging pests. To better understand the nectar physiology, particularly to determine the temporal dynamics of EFN metabolites in response to the wounding, a gas chromatograph-mass spectrometer (GC-MS) was used to perform metabolic profiling analyses of a G. hirsutum variety Deltapine 383 that has fully developed extrafloral nectaries. A total of 301 compounds were monitored, specifically 75 primary metabolites, two secondary metabolites and 224 unidentified compounds. The physical wounding treatment changed the EFN composition and lowered overall production. The accumulation of 30 metabolites was altered in response to the wounding treatment and threonic acid levels increased consistently. GC-MS combined with Kovat's analysis enabled identification of EFN secondary metabolites including furfuryl alcohol and 5-hyrdomethoxyfurfural, which both have antioxidant and antimicrobial properties that may protect the nectar against microbial pathogens. This study provides new insights into the wounding response of cotton plants in terms of cotton metabolites found in leaf glands and extrafloral nectar as well as highlighting some protective functions of secondary metabolites produced in foliar glands and extrafloral nectaries.

Exploring the binding interaction of Maillard reaction by-product 5-hydroxymethyl-2-furaldehyde with calf thymus DNA

BACKGROUND

5-Hydroxymethyl-2-furaldehyde (5-HMF), a by-product of the Maillard reaction, usually present in fried and baked food, may cause potential harm to the human body. Here, the interaction between 5-HMF and calf thymus DNA (ctDNA) under physiological buffer (pH 7.4) was studied using multi-spectroscopic methods combined with multivariate curve resolution-alternating least squares (MCR-ALS) chemometrics and molecular simulation techniques.

RESULTS

The concentration profiles and pure spectra of the three components (5-HMF, ctDNA and 5-HMF-ctDNA complex) were extracted from highly overlapping spectra using MCR-ALS analysis, which verified the formation of 5-HMF-ctDNA complex. The binding constant being of the order of 10³  L mol^-1 at four temperatures (292, 298, 304 and 310 K) indicated a weak affinity in the binding of 5-HMF to ctDNA. The binding interaction was mainly driven by hydrogen bonds and van der Waals forces. Viscosity analysis, melting assay, ionic strength effect and competitive fluorescence studies ascertained that 5-HMF bound to ctDNA through groove binding, and it tended to bind to guanine-cytosine rich region of ctDNA which was characterized using Fourier transform infrared spectra and molecular docking. Circular dichroism spectral analysis and DNA cleavage assays indicated that the ctDNA conformation was altered from B to A form and 5-HMF caused DNA damage at higher concentration.

CONCLUSIONS

The results suggested that 5-HMF bound to ctDNA through groove binding and caused DNA damage. This research may contribute to understand the binding mechanism of 5-HMF to ctDNA and to the assessment of the toxicological effect of 5-HMF in biological processes. © 2018 Society of Chemical Industry.

Inhibitory Effect of Hydroxymethylfurfural in Viability of BALB/C Mice Splenocytes

Background: This study was designed to discover if hydroxymethylfurfural (HMF) exposure modifies cell proliferation and DNA damage in BALB/c mice splenocytes. Methods: Mitogenesis in T cells and B cells was induced by Concanavalin A (Con A) and lipopolysaccharide (LPS). The colorimetric tetrazolium assay was used to evaluate cell proliferation. DNA damaging consequences were evaluated via measurement of 8-hydroxy-2-deoxyguanosine (8-OHdG) level in BALB/c mice splenocytes. Results: Spleen cells proliferation elicited by ConA, was dramatically suppressed by 25, 50 and 100 mM of HMF. However, there was not any significant difference between various concentrations of HMF. The same result was observed following treatment with LPS and HMF in different concentrations. Eight-OHdG concentration was elevated significantly in HMF treated groups compared with untreated control and mitogens. Conclusion: HMF was found to have immunosuppressing and DNA damaging properties in mM concentrations in mice splenocytes.

5-Hydroxymethylfurfural (HMF) levels in honey and other food products: effects on bees and human health

An organic compound known as 5-hydroxymethylfurfural (HMF) is formed from reducing sugars in honey and various processed foods in acidic environments when they are heated through the Maillard reaction. In addition to processing, storage conditions affect the formation HMF, and HMF has become a suitable indicator of honey quality. HMF is easily absorbed from food through the gastrointestinal tract and, upon being metabolized into different derivatives, is excreted via urine. In addition to exerting detrimental effects (mutagenic, genotoxic, organotoxic and enzyme inhibitory), HMF, which is converted to a non-excretable, genotoxic compound called 5-sulfoxymethylfurfural, is beneficial to human health by providing antioxidative, anti-allergic, anti-inflammatory, anti-hypoxic, anti-sickling, and anti-hyperuricemic effects. Therefore, HMF is a neo-forming contaminant that draws great attention from scientists. This review compiles updated information regarding HMF formation, detection procedures, mitigation strategies and effects of HMF on honey bees and human health.

Enzyme activity, amino acid profiles and hydroxymethylfurfural content in Ethiopian monofloral honey

The enzymes activity, hydroxymethylfurfural (HMF) and amino acids in honeys are relatively low. However, they play very significant role for honey quality. In this study, enzymes, amino acids and HMF contents of Ethiopian monofloral honeys were investigated. Diastase, invertase and HMF were analyzed based on the Harmonized International Honey Commission method and amino acids using amino acids analyzer (HPLC). Diastase activity ranged from 3.91 ± 0.730 (Schefflera abyssinica) to 13.6 ± 2.30 [Becium grandiflorum (L: Lalibella)]; invertase 36.5 ± 1.93 (Leucas abyssinica) to 4.85 ± 2.36 (Schefflera abyssinica); and HMF 0 ± 0 (Hypoestes and Leucas abyssinica) to 3.37 ± 1.73 (Croton macrostachyus). Significant variations were observed among Schefflera abyssinica honeys in diastase content, despite being from the same botanical origin. Significant variations were also observed among Becium grandiflorum honeys in invertase and diastase contents. Bees' geographical race and location affected enzymes activities. Lower level of enzymes could be an intrinsic characteristic of Ethiopian honey. Thus, enzymes activity alone cannot be a worthwhile indicator of quality for Ethiopian honey; besides diastase and invertase activity, the quality control of Ethiopian honeys should be supported by HMF parameters.

Analytical Methods Used in the Quality Control of Honey

Honey is a natural sweet substance produced by bees (Apis mellifera). In this work, the main parameters used in routine quality control of honey and the most commonly used analytical methods for their determination are reviewed. Honey can be adulterated with cheaper sweeteners or, indirectly, by feeding the bees with sugars. Therefore, methods for detecting and quantifying adulteration are necessary. Chromatographic techniques are widely used in honey analysis. More recently, techniques such as Raman, near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy in combination with chemometric data processing have been proposed. However, spectroscopy does not allow the determination of enzyme activities, one criteria of great importance for the honey trade. Methylglyoxal is an interesting compound for its antibacterial properties. Methods for its determination are also reviewed.

Effects of honey HMF on enzyme activities and serum biochemical parameters of Wistar rats

Hydroxymethylfurfural (HMF) is a by-product of thermal degradation of glucose and fructose. In this study, the effects of high HMF content of honey on biochemical parameters of rats were investigated. Experiments were conducted with 40 Wistar albino male rats, each weighing 250-350 g and covered a period of 5 weeks. The animals were divided into five groups. The first group was served as control group. HMF was injected subcutaneously at a dose of 200 mg/kg rat b.w. to the animals in group 2. Group 3 was fed with honey that contains 10 mg HMF/kg honey. In group 4 and 5, there were honeys that contain significantly high HMF content due to long storage period (181 mg HMF/kg honey) and heat process (140 mg HMF/kg honey). At the end of the feeding process, biochemical blood parameters of rats were investigated. It was observed that there were no differences among the glucose, triglyceride, HDL cholesterol, uric acid, Na, GGT, and ALP parameters of the groups. On the other hand, significant differences were observed among the cholesterol, LDL, BUN, creatinine, Ca, P, Mg, K, Cl, total bilirubin, LDH, CPK, AST, ALT, total protein, and pseudocholinesterase values of the rats. The highest adverse effects were obtained from group HMF, and it was followed by groups SH (stored honey) and HH (heated honey). It can be concluded that high HMF content of honey may affect the human health adversely; thus, HMF in honey must be controlled by beekeepers.

Preparation and preliminary application of 5-HMF@SiO2 micro-particles

We report an organic–inorganic hybrid composite of surface-modified silica gel with 5-hydroxymethylfurfural, which provided a new promising stationary phase for protein separation.

Genotoxicity of three food processing contaminants in transgenic mice expressing human sulfotransferases 1A1 and 1A2 as assessed by the in vivo alkaline single cell gel electrophoresis assay

The food processing contaminants 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 5-hydroxymethylfurfural (HMF) and 2,5 dimethylfuran (DMF) are potentially both mutagenic and carcinogenic in vitro and/or in vivo, although data on DMF is lacking. The PHIP metabolite N-hydroxy-PhIP and HMF are bioactivated by sulfotransferases (SULTs). The substrate specificity and tissue distribution of SULTs differs between species. A single oral dose of PhIP, HMF or DMF was administered to wild-type (wt) mice and mice expressing human SULT1A1/1A2 (hSULT mice). DNA damage was studied using the in vivo alkaline single cell gel electrophoresis (SCGE) assay. No effects were detected in wt mice. In the hSULT mice, PhIP and HMF exposure increased the levels of DNA damage in the liver and kidney, respectively. DMF was not found to be genotoxic. The observation of increased DNA damage in hSULT mice compared with wt mice supports the role of human SULTs in the bioactivation of N-hydroxy-PhIP and HMF in vivo.

Hydroxymethylfurfural: a possible emergent cause of honey bee mortality?

Hydroxymethylfurfural (HMF), a common product of hexose degradation occurring during the Maillard reaction and caramelization, has been found toxic for rats and mice. It could cause a potential health risk for humans due to its presence in many foods, sometimes exceeding 1 g/kg (in certain dried fruits and caramel products), although the latter still is controversial. HMF can also be consumed by honey bees through bad production batches of sugar syrups that are offered as winter feeding. In Belgium, abnormal losses of honey bee colonies were observed in colonies that were fed with syrup of inverted beet sugar containing high concentrations of HMF (up to 475 mg/kg). These losses suggest that HMF could be implicated in bee mortality, a topic that so far has received only little attention. This paper reviews the current knowledge of the presence of HMF in honey bee environment and possible consequences on bee mortality. Some lines of inquiry for further toxicological analysis are likewise proposed.