Formation Of 5-hydroxymethylfurfural Research Articles

Consumption of Minerals, Toxic Metals and Hydroxymethylfurfural: Analysis of Infant Foods and Formulae.

Infant foods and formulae may contain toxic substances and elements which can be neo-formed contaminants or derived from raw materials or processing. The content of minerals, toxic elements, and hydroxymethylfurfural (HMF) in infant foods and formulae were evaluated. The effect of storage temperature on HMF formation in infant formulae and its potential as a quality parameter was also evaluated. Prune-based foods contained the highest HMF content. HMF significantly increased when the storage temperature was elevated to 30 °C for 21 days. All trace elements were present in adequate amounts, while the concentration of nickel was higher when compared to those of other studies. The study indicates that HMF can be used as a quality indicator for product shelf-life and that the concentrations of minerals and toxic elements vary greatly due to the diverse compositions of foods and formulae. Such contaminants need to be monitored as infants represent a vulnerable group compared to adults.

Catechin-iron as a new inhibitor to control advanced glycation end-products formation during vinegar storage

Vinegar is a kind of popular condiment which has attractive color, flavor and functional properties. However, some potential harmful substances such as advanced glycation end-products (AGEs) will inevitably be generated by Maillard reaction during the brewing process and storage. In our study, it is concluded that catechin can reduce the formation of AGEs in both model vinegar system and the real vinegars. What's more, addition of iron can cooperate with catechin to enhance inhibitory effect up to 92.75 ± 5.24% and 89.77 ± 5.38% in Glu-Ala and Rib-Ala model vinegar system, respectively, and achieved highest inhibitory ratio about 75.52 ± 0.64% in apple vinegar. The corresponding mechanisms included reducing 5-hydroxymethylfurfural (5-HMF) formation and eliminating free radicals in the vinegar. Our study will provide a new idea for the application of catechin-iron as an addictive to assure the safety and the quality of vinegar.

Effects of adding honey at different temperatures to linden tea on antioxidant properties and hydroxymethylfurfural formation

Linden, a popularly consumed product, is prepared by different methods like infusion and decoction for treating diseases in children and adults. Due to linden’s effective compounds and its sweeteni...

Effect of Thermal Processing on Simultaneous Formation of Acrylamide and Hydroxymethylfurfural in Plum Purée

Effect of Thermal Processing on Simultaneous Formation of Acrylamide and Hydroxymethylfurfural in Plum Purée

Production of prebiotic 6-kestose using Zymomonas mobilis levansucrase in carob molasses and its effect on 5-HMF levels during storage

Fructooligosaccharides have important potential use in the food industry due to their properties such as solubility in water, stability in acidity of fruit juices and during storage, low-calorie value and prebiotic effects. In this study, for the first time, Zymomonas mobilis levansucrase was used for in situ 6-kestose production in carob molasses. The produced kestose was stable during storage at 20 °C for 4 months. The product was evaluated for color, non-enzymatic browning index and titratable acidity during storage and the quality of the product was found comparable to that of control. Furthermore, the decreased amount of sucrose resulted in the prevention of 5-hydroxymethylfurfural (5-HMF) formation during storage. As a result, carob molasses was converted into a high-quality prebiotic product with decreased sucrose content and reduced 5-HMF quantities, and a new method was developed to prevent 5-HMF formation in fruit juices and molasses.

Non-enzymatic browning and the kinetic model of 5-hydroxymethylfurfural formation in residual solution of vinegar soaked-soybean

Non-enzymatic browning of vinegar soaked-soybean residual solution was investigated using a model solution. A glycine-fructose-gallic acid model system was proposed by analyzing reducing sugars, amino acids, total phenolics, and pH value of the vinegar soaked-soybean residual solution. Based on the proposed model, the kinetics of 5-hydroxymethylfurfural (5-HMF) formation was also studied. The results showed that Maillard reaction and sugar pyrolysis might be the accurate mechanisms of non-enzymatic browning in vinegar soaked-soybean residual solution. The formation of 5-HMF in the model solution exhibited characteristics of the first-order kinetic model at temperature from 60 to 140 °C. The frequency constant kf was 450.65 /h, and the apparent activation energy Ea was 20.15 kJ/mol. Acetic acid, Fe2+, and Fe3+ significantly enhanced the browning rate and 5-HMF formation; whereas Ca2+, Mg2+, Na+, glucose oxidase, and H2O2 inhibited the browning rate.

Modelling Contaminant Formation during Thermal Processing of Sea Buckthorn Purée.

Background: The impact of thermal treatment on acrylamide (ACR) and hydroxymethylfurfural (HMF) formation was investigated for thermally treated sea buckthorn purée. Methods: An optimized procedure for minimizing ACR and HMF formation in thermally treated sea buckthorn purée was described. The precursors of ACR and HMF and their impact in heating of sea buckthorn purée to obtain jam-like products were also evaluated. Results: The contaminant content formed in samples was analyzed on thirteen running variants using a temperature range of 59.3–200.7 °C, and for heating durations between 5.9 and 34.1 min. The calculated equations of contaminant formation in sea buckthorn purée have established that the minimum content is formed at the lowest exposure time, between 10 and 20 min, for both ACR and HMF. The lowest ACR content was attained at 5.9-min exposure time and 130 °C temperature (0.3 µg/kg). For HMF the results revealed a lower quantity at 59.3 °C for 20-min exposure time (1.4 mg/kg). Conclusions: the found model is useful for the prediction of the best temperature/time conditions of the thermal treatment to obtain the lowest contaminates levels in the final product.

Effect of Dilute-acid Hydrolysis Conditions on Sugar and Productions from Paragrass

In this study, the productions of sugars as well as inhibitory compounds, e.g hydroxymethylfurfural (HMF) and furfural, from paragrass (Brachiaria mutica) were investigated using dilute acid hydrolysis. Sulphuric acid concentration of 1.0, 1.2, 1.5 and 2.0 wt% and reaction temperature of 120, 130, 140 and 150 °C for either 30 or 60 min were investigated. Xylose was found to be the major product at a maximum yield of 99±3 mg/g grass using 1.2 wt% H2SO4 and reaction temperature of 140 °C for 30 min. Analysis of variance (ANOVA) showed that for the reaction temperature between 120-140 °C, sulphuric acid concentration was the most important factor affecting the yields of hemicellulose sugars from paragrass. However, the temperature ≥ 150 °C caused the marked drop in all sugar compounds. At the optimal condition, the concentration of HMF was 0.16 g/l and furfural 0.09 g/l. The formation of HMF and furfural was almost linearly increased with increasing hydrolysis temperature between 120 and 150 °C. Furthermore, longer reaction times led to higher levels of HMF and furfural. The dilute acid hydrolysis in series with enzyme saccharification of paragrass yielded 122 mg total reducing sugar (TRS) per g grass in the enzyme hydrolysate.

Comparative study on the Maillard reaction of chitosan oligosaccharide and glucose with soybean protein isolate

Chitosan oligosaccharide (COS) has multiple biological properties and is hence promising in the modification of proteins through Mallard reaction. Its susceptibility to the reaction with soybean protein isolate (SPI) was evaluated by comparing with glucose (Glu). Conjugation with COS led to milder color change, less furosine and hydroxymethyl furfural formation, and fewer lysine/arginine consumption than with Glu, implying that COS was less susceptible to the Maillard reaction with SPI than Glu. Intrinsic fluorescence analysis indicated that different intermediate products were generated in the SPI-Glu and SPI-COS conjugates and the former intermediates were more prone to condensation to brown pigments. SDS-PAGE illustrated that COS inclined to conjugate with the small subunits of SPI. Conjugation with COS caused SPI unfolding and improved its emulsifying activity. Hence, COS has great potential in the modification of proteins through Maillard reaction and other attributes of the resultant conjugates, such as antioxidant and antibacterial activities, deserve further study.

Influences of stir-frying and baking on flavonoid profile, antioxidant property, and hydroxymethylfurfural formation during preparation of blueberry-filled pastries

Bakery products with fruit fillings are growing fast. Blueberry-filled pastries are widely consumed in China. This study aimed to investigate the effects of two thermal processing procedures (stir-frying and baking) on flavonoid profile, antioxidant property, and hydroxymethylfurfural (HMF) formation during preparation of blueberry-filled pastries. Stir-frying contributed the most to the variations in these values in blueberry filling. Anthocyanins (48%–53% reduction in total) were more susceptible to thermal processing than flavonols (11%–16%). Among anthocyanins, delphinidin glycosides (61%–67% reduction) were the most unstable, followed by malvidin (52%–58%), petunidin (40%–45%), and cyanidin (38%–41%). A high level of HMF (300 mg/kg) was formed during stir-frying. Except for anthocyanins, baking did not significantly influence HMF formation, flavonol degradation, and antioxidant property in the fillings. Stir-frying processing conditions rather than baking must be further investigated for nutrient retention and HMF inhibition.

Primary Investigation into the Occurrence of Hydroxymethylfurfural (HMF) in a Range of Smoked Products

5-Hydroxymethylfurfural (HMF) is produced in foods through many different pathways. Recently, studies have revealed its potential mutagenic and carcinogenic properties. Determination of HMF was originally used as an indicator of both the extent of thermal processing a food had undergone and food quality. It has been identified in a variety of food products such as bread, breakfast cereals, fruit juices, milk, and honey. In addition to the thermal processes that lead to the formation of HMF during thermal treatment, food smoking also creates conditions that result in the formation of HMF. This can take place within the food due to the elevated temperatures associated with hot smoking or by the proximity of the products of the pyrolysis of the wood matrix that is used for smoking (cold smoking). This may lead to further contamination of the product by HMF over and above that associated with the rest of the preparation process. Until now, there have been no studies examining the relation between the smoking procedure and HMF contamination in smoked food. This study is a primary investigation measuring HMF levels in three categories of smoked food products, cheese, processed meat, and fish, using HPLC-UV. The amount of HMF found in all three product categories supports our hypothesis that HMF levels are due to both internal pathways during processing and external contamination from the smoke generation matrix (wood) employed. The results ranged from 1 ppb (metsovone traditional Greek smoked cheese) to 4 ppm (hot-smoked ready-to-eat mackerel). Subsequently for smoked cheese products, a correlation was found between HMF and phenolic compounds generated by the smoking procedures and identified by SPME-GCMS. It was observed that cheese samples that had higher concentrations of HMF were also found to have higher concentrations of syringol and cresols. It is important therefore to understand the smoking procedure’s effect on HMF formation. This will aid in the development of mitigation strategies to reduce HMF formation while retaining the flavour of the smoked products.

Effects of pH on steam explosion extraction of acetylated galactoglucomannan from Norway spruce

BackgroundAcetylated galactoglucomannan (AcGGM) is a complex hemicellulose found in softwoods such as Norway spruce (Picea abies). AcGGM has a large potential as a biorefinery feedstock and source of oligosaccharides for high-value industrial applications. Steam explosion is an effective method for extraction of carbohydrates from plant biomass. Increasing the reaction pH reduces the combined severity (R^{prime}_{0}) of treatment, affecting yields and properties of extracted oligosaccharides. In this study, steam explosion was used to extract oligosaccharides from Norway spruce wood chips soaked with sodium citrate and potassium phosphate buffers with pH of 4.0–7.0. Yields, monosaccharide composition of released oligosaccharides and biomass residue, their acetate content and composition of their lignin fraction were examined to determine the impact of steam explosion buffering on the extraction of softwood hemicellulose.ResultsReducing the severity of steam explosion resulted in lower yields, although the extracted oligosaccharides had a higher degree of polymerization. Higher buffering pH also resulted in a higher fraction of xylan in the extracted oligos. Oligosaccharides extracted in buffers of pH > 5.0 were deacetylated. Buffering leads to a removal of acetylations from both the extracted oligosaccharides and the hemicellulose in the residual biomass. Treatment of the residual biomass with a GH5 family mannanase from Aspergillus nidulans was not able to improve the AcGGM yields. No hydroxymethylfurfural formation, a decomposition product from hexoses, was observed in samples soaked with buffers at pH higher than 4.0.ConclusionsBuffering the steam explosion reactions proved to be an effective way to reduce the combined severity (R^{prime}_{0}) and produce a wide range of products from the same feedstock at the same physical conditions. The results highlight the impact of chemical autohydrolysis of hemicellulose by acetic acid released from the biomass in hydrothermal pretreatments. Lower combined severity results in products with a lower degree of acetylation of both the extracted oligosaccharides and residual biomass. Decrease in severity appears not to be the result of reduced acetate release, but rather a result of inhibited autohydrolysis by the released acetate. Based on the results presented, the optimal soaking pH for fine-tuning properties of extracted AcGGM is below 5.0.

An Approach of Utilizing Water-Soluble Carbohydrates in Lignocellulose Feedstock for Promotion of Cellulosic l-Lactic Acid Production.

Agricultural lignocellulose biomass generally contains certain amounts of water-soluble carbohydrates (WSC) such as glucose, fructose, or sucrose. These sugars are generally degraded in pretreatment at high temperature or discharged with wastewater in a detoxification process. This study proposed an approach of utilizing frequently ignored water-soluble carbohydrates for promotion of cellulosic l-lactic acid production. A simple solid state fermentation was performed during a corn stover storage period to convert the sugars into l-lactic acid and then a dry biorefining technology was applied to convert cellulose and hemicellulose fractions into the same l-lactic acid product. The 5-hydroxymethylfurfural (HMF) formation in pretreatment was significantly reduced and the consequent biodetoxification time was shortened. l-Lactic acid production was increased from 130.2 g/L to 139.0 g/L, and the minimum l-lactic acid selling price was reduced by 5.9%. This study provided an important option of biorefinery processing technology for production of value added biochemicals.

Kinetic changes of antioxidant parameters, ascorbic acid loss, and hydroxymethyl furfural formation during apple chips production

In this study, the kinetic change of the antioxidant properties were determined during apple chips production using three different cultivars. Using a rotary forced-air dryer, apple slices were dried at three different temperatures (65, 70, and 75°C). The ascorbic acid content, total phenolic content (TPC), total flavonoid content (TFC), Oxygen Radical Absorbance Capacity (ORAC) and Trolox Equivalent Antioxidant Capacity (TEAC), and hydroxymethylfurfural content were analyzed. Phenolic compounds of apple chips were also identified by chromatographic separation. Thermal degradation of ascorbic acid was fitted to first-order reaction kinetics. TPC, TFC, ORAC, and TEAC values, and hydroxymethylfurfural content increased with drying time and temperature where the data were fitted to first-order and zero-order reaction kinetics. Reaction rate constants were influenced by temperature, based on the Arrhenius model. The primary phenolic compounds of apple chips were gallic acid, chlorogenic acid, catechin, caffeic acid, epicatechin, and rutin. Practical applications Dietary antioxidants with health benefits have increased attention on fruit and vegetable products. The processing of fruits and vegetables affects their antioxidant properties as well as their quality. Apple chips are dehydrated, ready to eat, fruit-based snacks with desirable sensory properties. The results of this article will contribute to an understanding of the thermal kinetics of antioxidant properties and phenolic content during apple chip production. The kinetic results may be useful for the design of dryers and optimization of the drying conditions.

Parameters affecting 5-hydroxymethylfurfural exposure from beer

ABSTRACT5-Hydroxymethylfurfural (HMF) is generated during food and beverage heating processes and/or storage. Its daily intake, estimated as 4–10 mg day−1, is several orders of magnitude higher than other process contaminants. Beer can be of relevance to the evaluation of HMF exposure; however, the information concerning its occurrence in different types of beer and during product storage is scarce. Therefore, the major goal of this work was to assess the amounts of HMF in different commercial beers, as well as the impact of storage, to deepen knowledge about the contribution of beer to HMF exposure. Blonde beers presented a mean content of 4.29 ± 1.05 mg L−1, which was significantly lower (P ≤ 0.05) than those obtained for amber (6.84 ± 0.75 mg L−1) and dark beers (6.99 ± 0.52 mg L−1). Additionally, to study kinetic of HMF formation, fresh pilsner beers were stored at 30, 40 and 50°C during 40 days; a zero-order reaction was observed. The dependence of the rate constant on temperature was described by the Arrhenius equation and calculated activation energy was 101.85 kJ mol−1. Storage can increase drastically HMF content, which means higher exposure for consumers. Thus, beer contribution to HMF exposure should not be neglected, since the intake of 1 L of beer entails a consumption of 4–7 mg of HMF or even more, depending on storage time and temperature.

Investigating 5-hydroxymethylfurfural formation kinetic and antioxidant activity in heat treated honey from different floral sources

The quality and biochemical properties of honey are affected by heating or during storage period. The most important biochemical reaction that occurs in this process is the Maillard reaction. HMF (5-hydroxymethylfurfural) is one of the major intermediate products in the Maillard reaction that can lead to quality reduction in heated honey. In this study, the effect of heating on the antioxidant activity, and colour values as Maillard reaction indicators of three different botanical honeys were investigated; the HMF formation was also determined. Temperatures of 50, 70 and 80 °C were applied on the honeys between 0 and 48 h. Total phenolic content, ferric reducing/antioxidant power and scavenging of 2,2-diphenyl-1-picrylhydrazyl free radical assays are used to determine the antioxidant capacity. Results showed that the formation of HMF and the antioxidant properties of honeys were significantly increased during the heating process. Pure HMF compound also showed lower antioxidant activity. The formation of HMF has higher degree of linearity in the fit of the zero order reaction and also it was the highest in the chestnut honey. Furthermore, it was found that as the biochemical value of the honeys increased, the HMF formation decelerated.

RETRACTED: Corn stover pretreatment by metal oxides for improving lignin removal and reducing sugar degradation and water usage

Five metal oxides, Fe2O3, CuO, NiO, ZnO, and MgO, were investigated as catalysts to improve lignin removal and reduce sugar degradation during corn stover pretreatment. Liquid hot water (LHW) pretreatment was used as control. Among the five metal oxides, MgO was the most suitable for biomass pretreatmen. The optimal pretreatment condition was the solid/liquid ratio of 1/10 with 0.10 mol/L MgO at 190 °C for 40 min. The fermentable xylose (85%) and glucose (97%) from MgO pretreatment were equivalent to those (89 and 95%) from LHW pretreatment, and lignin removal was 1.5-fold more than that from LHW pretreatment. The pH of the resulting biomass slurry was close to 7.0 and without furfural and 5-hydroxymethylfurfural formation. Thus, the water-washing step for inhibitor removal can be omitted. The biomass liquor can be used directly for downstream hydrolysis and fermentation. Acid-resistant equipment is not required due to the absence of acids.

5-Hydroxymethylfurfural (HMF) formation during subcritical water extraction.

The aim of this study was to investigate the effect of material type (artichoke leave, lemon peel, flaxseed meal), extraction temperature (50, 100, 120, 140, 160, 180, 200°C) and static extraction time (5, 15, 30, 45min) on 5-hydroxymethylfurfural (5-HMF) formation during subcritical water extraction. 5-HMF content of artichoke leave and lemon peel extracts increased 7.2 and 26.1 times with the rise of extraction temperature from 160 to 180°C for 5min during subcritical water extraction, respectively. Besides, 5-HMF content of artichoke leave, lemon peel and flaxseed meal extracts increased 1.4, 2.0 and 4.5 times as static extraction time increased from 15 to 45min at 180°C during subcritical water extraction, respectively. The highest 5-HMF content of artichoke leave and lemon peel extracts were obtained as 58.83 and 231.21mg/L at 180°C and 45min, respectively. However, for flaxseed meal, the highest 5-HMF content (222.94mg/L) was obtained at 200°C and 15min during subcritical water extraction.

The Extent of Hydroxymethylfurfural Formation in Honey by Heating Temperature and Duration

Hydroxymethylfurfural (HMF) is one of the important parameters to determine the quality and freshness of honey relating to thermal treatment and storage condition, respectively. Many studies have been extensively carried out to investigate the effect of heating temperature and duration on the formation of HMF. These data were collected from literature, and critically analyzed using statistical techniques including multivariate data analysis and neural network modelling. It was found that the formation of HMF follows zero order kinetics at low temperature (30-40oC), but first order kinetics at high temperature (90-100oC). No significant trend was found for the data between 50-80oC. A three dimensional bubble plot shows that the effect of heating duration is higher than temperature, especially at high temperature (90-100oC). An artificial neural network was also trained by the functions of log sigmoid and pure linear transfer using previously reported data on HMF content in relation with heating temperature and time as inputs in model development. The network was proven to show the goodness of the fit with high correlation coefficient, R2 0.9163 and low root mean square error, RMSE 0.0019 to the experimental data generated from the present study using Tualang honey heated at 90oC for 0-5 hours. The thermal treatment on Tualang honey have also shown to have moderate change on the chemical profile which was generated from liquid chromatography tandem mass spectrometry. The first two principal components have shown to have 33-38 % of the total variance in the chemical profile based on principal component analysis.

Chemical transformation of food and beverage waste-derived fructose to hydroxymethylfurfural as a value-added product

A novel alternative bioconversion and chemical transformation method for valorisation of food and beverage (F&B) waste to hydroxymethylfurfural (HMF) is reported. Solid-to-liquid ratio of 70% was applied to hydrolyse F&B waste by glucoamylase and sucrase to yield a hydrolysate consisted of glucose and fructose. After impurity removal using chromatography columns, the purified hydrolysate was processed by glucose isomerase to produce syrup with a fructose-to-glucose ratio of 1:1. After removal of the residual impurities using ion exchange columns, Simulated Moving Bed system was applied to separate sugars in fructose-glucose syrup. The resultant high-fructose syrup contained 89.0 g/L fructose, which was demonstrated as an ideal feedstock for the synthesis of HMF. By employing a commercial solid acid catalyst (Amberlyst 36), 71 mol% HMF with a high selectivity of 77 mol% was generated from this high-fructose syrup under mild microwave heating at 140 °C within 40 min. The increase in catalyst loading accelerated both HMF formation and HMF-consuming side reactions, underscoring the trade-off between the conversion rate and product selectivity. The solid catalyst can be recovered and successfully reused for four runs with the HMF yield at 70 mol%. An overall conversion yield of 30 g HMF/kg F&B waste was achieved. This work emphasises a novel integration of chemical and biological technologies for selective production of HMF from mixed F&B waste.