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In the present work, a series of Bronsted and Lewis hybrid, magnetic, dendritic fibrous silica microsphere core shell particles with an open and easily accessible mesopore channels as the catalyst supports (Fe3O4@SiO2@KCC-1) were prepared, impregnated with aluminum (10 wt%) followed by encapsulation of different loadings of tungstophosphoric acid (PTA) from 10 to 40 wt% into mesoporous channels of fibrous silica shell (Fe3O4@SiO2@KCC-1/Al10/PTAx). They are utilised for the efficient and clean production of biomass-derived liquid fuel 5-ethoxymethylfurfural (EMF) through direct etherification of hydroxymethylfurfural (HMF) and one-pot conversion of fructose and other carbohydrates. High EMF yields of 93.1%, 62.2%, 23.9%, and 21.4% were obtained, when HMF, fructose, sorbose, and sucrose were subjected as substrate, respectively. These catalysts were characterised by XRD, py-FTIR, TGA, N2-physisorption, SEM and TEM-EDX mapping. Importantly, the catalyst could be reused at least four times almost without a significant loss of activity.

Selective conversion of hydroxymethylfurfural to diformylfuran using copper hydroxide nitrate.

In this work, we report that FeCl3, a benign Lewis acid, could be used as a catalyst in the γ-valerolactone (GVL)/H2O solvent system to facilitate efficient pretreatment of Chinese silvergrass. The results showed that approximately 87.8% of xylan and 75.8% of lignin were removed by 80% GVL under 170 °C using 50 mM FeCl3 as a catalyst. The solubilized carbohydrate fractions in the pretreatment liquor were mainly composed of monosaccharides (glucose and xylose) rather than oligosaccharides (glucose oligomers and xylose oligomers) and inhibitors (furfural, hydroxymethylfurfural, formic acid and acetic acid). Moreover, FeCl3 decreased the transesterification of GVL with hydroxyl groups on the cellulose surface and resulted in more easily degraded cellulose. Approximately 96.5% of cellulose and 92.2% of xylan in the pretreated Chinese silvergrass were converted to fermentable monosaccharides by 10 FPU/g cellulases. This study indicated that FeCl3-catalyzed GVL solvent could efficiently deconstruct biomass and increase the cellulose digestibility, which provided a novel, GVL-based pretreatment system for processing biomass.

Background: \ud 2,2,6,6-tetramethylpiperidin-oxyl (TEMPO) accompanied with Cu has been validated as a promising oxidative catalytic process for oxidizing 5-hydroxymethylfurfural (HMF) to value-added products. Since Cu-O cluster plays an important role in TEMPO-based HMF oxidation, and N-O moiety would facilitate the catalytic cycle of TEMPO regeneration, an interesting solid-phase material, copper nitrate hydroxide (CNH) (Cu2(OH)3NO3) is proposed for the first time for co-catalyzing TEMPO to oxidize HMF into a valuable product, 2,5-diformylfuran (DFF).\ud \ud Methods: \ud In particular, a CNH with a 2D elliptical and porous surface is fabricated to become the leaf-like porous CNH (LPCNH) to maximize surface contact via a relatively simple procedure, and LPCNH would be an advantageous catalyst with TEMPO for converting HMF into DFF.\ud \ud Significant findings: \ud While TEMPO or LPCNH was unable to oxidize HMF into DFF, the combination of LPCNH/TEMPO rapidly, and efficiently converted HMF to DFF with high selectivities. At 140 °C, a significantly high YDFF = 99.3% with SDFF = 100% can be obtained, and surpass almost all reported values, indicating that LPCNH+TEMPO is advantageous and selective to convert HMF into DFF. LPCNH could be also reusable for co-catalyzing with TEMPO for converting HMF to DFF. These findings validate that LPCNH is certainly a useful heterogeneous catalyst for valorizing HMF.

A decarbonylation free, polystyrene-supported, Pd (Pd@PS)-catalysed carbonylative esterification of the hydroxy group of 5-hydroxymethyl furfural (5-HMF) to its corresponding aryl esters has been developed. The use of Pd@PS, oxalic acid as CO source, and aryl halides was first explored for the aryl ester of 5-HMF synthesis. Here, we investigated the vital role of a polystyrene support to avoid the commonly known decarbonylation of 5-HMF. The reaction exhibits vast substrate scope with comparably good yield and catalyst recyclability.

The aim of the study was to prepare liquid invert sugar from sugar beet dilute molasses by acidic hydrolysis and using powdered activated carbon (PAC) for purification. The effects of applied PAC concentrations (0.61, 0.78 and 1.12% PAC) at pH 4.5 were evaluated by tracking the changes in molasses quality attributes. Additionally, the impact of storage time (1, 15, 30, 45 and 60 days) at different temperatures (4 and 25 °C) on color, turbidity, reducing sugars and hydroxymethylfurfural (HMF) content in treated dilute molasses was investigated. The results showed that reducing sugars content increased during storage period regardless of applied PAC amount and storage temperatures. Consequently, the color was significantly raised during storage time and temperatures while lowest color was observed in sample with 1.12% PAC stored at 4 °C. Furthermore, after initial decrease in HMF and turbidity in the liquid invert sugar, an increase in corresponding parameters was noticed in higher or lesser extent depending on storage temperatures. Accordingly, it is suggested that the treatment with 1.12% PAC and storage at 4 °C is suitable for liquid invert sugar production.

Honey, rich with polyphenols, vitamins, proteins, organic acids and minerals, and is supersaturated solution of sugars. Gamma irradiation could be a physical food preservation technique which protects against food related-insects and microbial contamination and increases the shelf life of some products. The present research was investigated the effect of γ-irradiation (0.0, 2.5, 5.0 and 10.0 kGy) on the physicochemical possessions of the substances of honey; phenolic and flavonoids content in addition to the antioxidant activity by DPPH radical. Diastase No. is also identified with and without gamma irradiation. After γ-irradiation a minor decrease in moisture content was observed while color intensity was significantly increased by elevating irradiation dosage height mainly dose intensity 10.0 kGy which gave the premier color intensity compared with control. But there was no significant difference in the pH values and total soluble solids (TSS%) as well as sugars% of honey samples. Significant increases within the phenolic content were observed with the use of γ-rays particularly at dose 10.0 kGy which gave the main content relative to the control, while a trivial increase in the flavonoid content was obtained within the rise of the γ-irradiation dose. The findings have also shown that free radicals can be scavenged by honey and reveal high activity of antioxidants. Hydroxymethylfurfural is reduced by raising the irradiation dose, in converse diastase No. is enlarged by amplifying the level of the γ-rays. Also, the results showed that the inhibition zones varied according to the irradiation dose level, the dose level 10.0 kGy was more effective for inhibiting the growth of both Gram-positive and Gram-negative bacteria as well as fungal development. The lung cancer cells (A549) showed a decrease in cell viability and density, irradiated honey with dose level 10.0 kGy gave the lowest IC50 (6.08 mg/ml). Honey treated with a dose of 10.0 kg of gamma rays did not affect the physical and biochemical properties of honey and was more effective as an antimicrobial and anti-lung cancer, and the quality of honey remained unchanged upon radiation treatment.

Objective: To determine the physicochemical properties of honey to help ascertain its quality. The properties investigated in the present work are specific gravity, refractive index, moisture content, total solids, pH, free acidity, electrical conductivity, and hydroxymethylfurfural (HMF). Methods/Statistical analysis: To determine properties of honey such as refractive index, moisture content, pH, free acidity, electrical conductivity, and hydroxymethylfurfural, the procedures prescribed by the International Honey Commission were followed. Specific gravity was determined using the method described by Rebiai et al. Total solids was calculated by the formula given by Amin et al. Statistical analyses were carried out in Microsoft Excel 2016, and all readings were presented as mean±standard deviation. Correlation studies were also used wherever applicable. Findings: The moisture content lies in the range (16.6±0.4) g/100g to (19.4±0.3) g/100g. The total solids of all honey samples were above 80%. The pH varies from (3.59±0.02) to (3.73±0.01). The free acidity recorded a minimum of (32.3±1.5) meq/kg and a maximum of (42.0±2.0) meq/kg. The honey samples recorded electrical conductivities between (0.51±0.15) mS/cm and (0.61±0.25) mS/cm. The HMF varies from (8.9±0.2)mg/kg to (34.2±0.2) mg/kg. All the properties that were measured were well within the range prescribed by international agencies responsible for the quality control of Honey. Novelty: Adulteration of honey is a major concern as it affects the health and well being of a person. The recent study by the Centre for Science and Environment, New Delhi which reported adulteration of honey by eight household brands in the Indian market is a cause of alarm. A noteworthy feature of the current study was that it highlighted the superior quality of honey from traditional bee-keepers of Sohra, which even have the potential for export. No adulteration was detected relative to the parameters being investigated. Keywords Sohra, Bee, Honey, Physicochemical properties, Quality, Adulteration

A cold-induced-homogeneous liquid–liquid extraction method combined with deep eutectic solvent-based dispersive liquid–liquid microextraction has been done to extract several endocrine disrupting compounds (phenol, p-chlorophenol, p-nitrophenol, octylphenol, methyl paraben, ethyl paraben, butyl paraben, and bisphenol A) and hydroxymethylfurfural from honey samples before their determination by gas chromatography–mass spectrometry. In this method, two ternary deep eutectic solvents including tetrabutyl ammonium chloride: dichloroacetic acid: ethylene glycol (hydrophilic) and tetrabutyl ammonium chloride: dichloroacetic acid: decanoic (hydrophobic) acid deep eutectic solvents are prepared and used as the extraction solvents in the developed method. The analytes are extracted by a two-step extraction procedure in which they are first extracted into the hydrophilic deep eutectic solvent and then transferred into a few microliters of the hydrophobic deep eutectic solvent for more concentration. In both steps, phase separation is done by centrifugation at low temperature. The method was optimized and validated and the results showed that the method had low limits of detection (0.21–0.50 ng g−1) and quantification (0.72–1.7 ng g−1), wide liner ranges, and an acceptable repeatability (relative standard deviation≤12). Lastly, the developed method was applied on different honey samples and bisphenol A, p-nitrophenol, and hydroxymethfurfural were found in some of them.

In this study, the conversion of corn straw, sorghum and cellulose into valuable chemicals (furfural, 5-hydroxymethylfurfural, levulinic acid) in different ionic liquid-water medium were investigated. Different reaction parameters such as reaction temperature, time and solvent ratio were optimized to achieve the highest conversion of biomass and selectivity of the products. Under the optimal reaction conditions (180 °C, 30 min, 1:5 ratio), 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM]HSO4) was found to display the highest efficiency which can be attributed to the acidic character of the ionic liquid. 117.4 mg levulinic acid, 11.8 mg 5-hydroxymethylfurfural and 9.4 mg furfural were obtained per g of sorghum. The results showed that 5-fold higher quantity of LA was obtained from sorghum biomass in comparison with pure cellulose. In addition, Amberlyst-15 was examined as a solid acid catalyst for conversion of cellulose in [BMIM]HSO4-water solvent system resulting in 4.6-fold increase in the quantity of levulinic acid. This study provides an alternative single step approach for production of valuable chemicals from renewable biomass.

Background: Honey is one of the most valuable foods that used in human societies to treat many diseases due to its healing properties for centuries. The lack of an objective way to distinguish natural honey from counterfeit honey has strengthened the field of profiteering in this area and has led to the supply of counterfeit honey instead of natural honey. So honey quality must be controlled analytically with the aim of guaranteeing the reality and preserving the consumer from commercial speculation. Objective: The present study was conducted to evaluate 24 samples of 9 commercial brands of honey in Tehran’s markets with number 1 to 9 (1-AB, 2-TF, 3-DP, 4-JK, 5-SN, 6-SK, 7-IM, 8-MD, and 9-MH). A number of physical, chemical, and biological parameters of the samples were evaluated. Methods: Carbohydrate composition was determined by GC/Mass to evaluate the contents of fructose, glucose, and sucrose. 5-hydroxymethyl-2-furfuraldehyde (HMF) was quantified by HPLC-UV and other physicochemical quality parameters including moisture, pH, proline content; and diastase activity were also evaluated according to the Codex Alimentarius. Results: Only 2 brands met all major international specifications. Although all the parameters of the other brands were conformed, the diastase activity was not in a specific range. Conclusion: The diastasis activity is considered as the most important factor to evaluate honey quality based on the results of this study.

The sweet potato root, a potent source of starch which is being considered as an efficient alternative for fuel ethanol production in recent times. The starchy substrate needs to be subsequently dextrinized and saccharified so as to enhance the utilization of its carbohydrates for ethanol production. In the present investigation, acid-enzyme process was conducted for the dextrinization and saccharification of sweet potato root flour (SPRF). The best optimized condition for dextrinization was achieved with an incubation period of 60 min, temperature 100 ºC and 1M HCl. However, for saccharification, the best result was obtained with an incubation of 18 h, pH 4, temperature 65 ºC and 1000 U concentration of Palkodex®. After the dextrinization process, maximum concentrations of total sugar and hydroxymethylfurfural (HMF) [380.44 ± 3.17 g/kg and 13.28 ± 0.25 mg/g, respectively] were released. Nevertheless, after saccharification, 658.80 ± 7.83 g/kg of total sugar was obtained which was about 73% more than that of dextrinization. After successful dextrinization and saccharification, the structural, chemical and elemental analysis were investigated using techniques such as scanning electron microscopy (SEM), Fourier-transforms infrared spectroscopy (FTIR) and energy-dispersive X-ray fluorescence spectrophotometer (EDXRF), respectively. Effective hydrolysis was demonstrated in thin layer chromatography (TLC) where the HCl was able to generate monomeric sugar such as glucose and maltose. On the other hand, only glucose is synthesized on the mutual effect of HCl and Palkodex®. The SEM findings indicate that the rough structure of both dextrinized and saccharified sample was gained due to the vigorous effect of both acid and enzyme subsequently. The saccharified SPRF when subjected to fermentation with Saccharomyces cerevisiae and Zymomonas mobilis separately, it was observed that Z. mobilis produced more stretching vibration of –OH than S. cerevisiae, which evidenced the better production of bioethanol. Additionally, evaluation of the influence of S. cerevisiae and Z. mobilis through elemental analysis revealed upsurge in the concentrations of S, Cl, Ca, Mn, Fe and Zn and decline in the concentrations of P, K and Cu in the fermented residue of S. cerevisiae and Z. mobilis, however, Z. mobilis showed little more variation than that of S. cerevisiae.

Oligosaccharide analysis is commonly done by acid hydrolysis and following HPLC analysis. A major problem is the incomplete hydrolysis of oligosaccharides and disaccharides and the increasing formation of volatile furfural from pentose monomers and hydroxymethylfurfural (HMF) from hexose monomers. This paper optimizes the conditions of hydrolysis approaches and proposes a method for oligosaccharide quantification. The optimal condition for hydrolysis of model xylan from corn cob was found to be for 100 °C hydrolysis temperature, 120 min hydrolysis time, and 2 wt% sulfuric acid concentration. Under these conditions, the total free and bound xylose yield was 77.4% and hemicellulose conversion 87.4% respectively; no degradation products were found. The optimal conditions for hydrolysis of model xylan from beech wood were found to be for 120 °C hydrolysis temperature, 120 min hydrolysis time, and 2 wt% sulfuric acid concentration. Under these conditions, the total free and bound xylose yield was 65.1% and hemicellulose conversion 70.5% respectively; no degradation products were found. For pentosan hydrolysate, conditions were further optimized (110 °C, 60 min, 2 wt% H2SO4). Standard addition of xylan from the corn cob for hydrolysation showed similar conversion rates (< 2% deviation); no matrix effects were detected.

The transformations of carbohydrates into the platform substances such as furfural, hydroxymethylfurfural (5-HMF), lactic acid, etc. are actual environment-friendly processes. Herein, glucose transformation in an aqueous medium (10 wt.%) at 160 °C over synthesized nickel modified zeolites Y, M and ZSM-5 has been studied. The catalysts have been characterized by using FTIR spectroscopy, pyridine adsorption with IR-spectroscopic control, ammonia TPD, low-temperature nitrogen adsorption/desorption, and TEM. Utilizing HPLC, GC and 13C NMR the reaction products were identified. The 5-HMF molar yields over 5NiHY, 5NiHZSM-5, and 5NiHM were 8.5, 14, and 16%, respectively. Glucose conversion was practically quantitative. To investigate deactivated samples, FTIR and DTA/TG techniques have been used. The 5NiHM and 5NiHZSM-5 catalysts have showed a twice-lower weight of deposits (10 wt.%) than 5NiHY with the biggest total acidity. Bifunctional Lewis/Bronsted acid zeolite catalysts with Lewis acidity predominance demonstrate better performance in glucose transformation. The balance between acidity of the catalyst and textural properties is stated to play a key role in the transformation of glucose into 5-HMF. Nickel-containing zeolite ZSM-5 and M can be considered as promising catalysts for glucose conversion. Perspective trends in related research are provided.

This study aims to perform kinetic and thermodynamic analysis of subcritical water hydrolysis (SWH) of bakery leftovers. Hydrolysis kinetics of leftover croissants (LC) and leftover doughnuts (LD) into monosaccharides and by-product (hydroxymethylfurfural, HMF), via subcritical water hydrolysis, were studied in temperature range of 100 to 240°C for 6 to 30 minutes and solid loading of 10% (w/v). The monosaccharides yield increased from 100 to 200°C, but it decreased when the temperature further increased from 220–240°C due to degradation of monosaccharides into its by-product (HMF). The activation energy (Ea) monosaccharides degradation was higher than its formation: 104.87 and 88.55 kJ/mol (LC) and 104.69 and 75.72 kJ/mol (LD). The positive values of ΔG# signified that the SWH for sugar recovery from LC and LD is an endergonic reaction.

The present study was carried out to investigate the physicochemical properties of blended raw honey samples collected from three different locations from Kannad taluka of Aurangabad district (MS). The parameters like moisture content, pH, electrical conductivity, total reducing sugars, glucose, fructose, fructose glucose ratio, sucrose, Hydroxymethylfurfural (HMF), proline, protein content, Vitamin C, lipid content, were analyzed by AOAC method (2000). The results clearly indicate that the samples compared favorably with samples in many parts of the world and also fall within the limits of international standards. The variations in the physicochemical properties of honey samples are related to differences in the floral sources, climatic conditions and site of collection to the studied area. Overall the results indicate that the nutritional quality of honey was different from species to species and from location to location.

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

3 Figuras.-- 4 Tablas, The application of thermal pretreatments to facilitate its anaerobic digestion has associated phenols and furans production, which are commonly identified as inhibitory compounds. Phenols and furans extraction can be done from a liquid phase produced after the thermal pretreatment. In the present study this dephenolized liquid phase (DLP) showed an increase of 42% in methane yield compared to the raw liquid phase (LP) demonstrating the inhibitor character of such compounds. The main extracted phenols and furans were: 3,4-Dihydroxyphenylglycol (DHPG), Hydroxytyrosol (HT), Tyrosol (Ty), Vanillic acid (AcV), Hydroxymethylfurfural (HMF), Vanillin (V) and Furfural (F).This study also aimed to evaluate the individual effect on methane production of these specific phenols and furans the within the mixture of several ones from LP. The evaluation of the individual compounds over the methanogenesis of a dephenolized liquid phase showed that only V was inhibitory on both methane yield and methane production rate. HMF had a significantly negative effect on methane yield, but improved the methane production rate instead. Ty, F, DHPG and HT favoured the methane yield and production rate. Additionally, it was observed that negative effect of some individual phenols and furans was counteracted by the positive effect of other compounds., This work was supported by the Asociación Universitaria Iberoamericana de Postgrado through the call Programa de Becas de Movilidad entre Universidades Andaluzas e Iberoamericanas 2017. The authors are also very grateful to the Spanish Ministry of Economy and Competitiveness for funding this research through the project CTM2014-55095-R. In addition, the authors are grateful to “Becas Chile: CONICYT-PFCHA/MagísterNacional/2017-22122499” and Universidad Técnica Federico Santa María by “DGIIP Project number PLI_18_26” and “Programa de Incentivos a la Iniciación Científica (PIIC)”, and São Paulo Research Foundation (FAPESP process 2019/21370-7).

In this research, pomegranate molasses, pomegranate sour sauces and pomegranate jams were evaluated in terms of some physicochemical properties including hydroxymethylfurfural, total phenolic content, antioxidant capacity and bioaccessibility. While ascorbic acid of these products ranged between 0.89-19.78 mg 100g-1, total phenolic contents changed between 31.40-2061.10 mg gallic acid equivalent 100g-1. Antioxidant capacities of the products were determined as 34.01-2377.52 mg trolox equivalent 100g-1 with DPPH assay and 18.9-6439.0 mg trolox equivalent 100g-1 with CUPRAC assay. The bioaccessibilities regarding phenolic substance and antioxidant capacity after simulated gastrointestinal digestion ranged between 74-247% and 53-213%, respectively. High HMF levels, which were reflected on color and sensory features, have indicated the necessity of improving the production and storage conditions. On the other hand, the highest ascorbic acid, total phenolic content and antioxidant capacity of pomegranate molasses and the bioaccessibility of pomegranate jams in terms of antioxidants showed the importance of consumption of these products in the daily diet. So, this study can be regarded as a case surveillance study that can be used by producers, nutritionals and authorities to make assessments on manufacturing conditions, consumer health and nutrition.

Cassava pulp (CP) is considered as a major and low-cost agro-industrial solid byproduct of cassava starch processing, where 48% of starch granules was still entrapped in its complex lignocellulosic matrix of cell wall structure with 21% cellulose and 8% hemicellulose. In this study, the liquid hot water (LHW) pretreatment was aimed to disrupt the cell wall structure of CP and solubilized hemicellulose and starch into saccharides to enhance biomethane production. Reaction conditions of LHW pretreatment, temperature (160–200 °C), and time (0–30 min) were optimized by response surface methodology. LHW pretreatment at 187 °C for 7 min boosted the highest level of starch and hemicellulose solubilization into the liquid phase, resulting in the maximized glucose yield of 444 mg/gCP. Starch and hemicellulose were mostly removed from CP at 99 and 79%, respectively, while 68% cellulose and 10% lignin particularly remained in solid residue. The disrupted cell wall structure and crystalline cellulose after LHW pretreatment were also observed. Microbial inhibitors such as furfural and hydroxymethylfurfural were found in low concentration at 31 and 32 μg/mL, respectively. In addition, there were no lag phase and inhibitory effect during anaerobic digestion of the pretreated CP. Biochemical methane potential of the LHW-pretreated CP showed the methane production rate and methane yield at 1.6 times and 35% higher than that of non-pretreated CP, respectively, by shortening anaerobic digestion time from 22 d to 10 d. It was shown that LHW was an efficient chemical-free method for enhancing biodegradability of CP in conversion to biomethane.

Diols prepared via solvent-free acetalisation of hydroxymethylfurfural with glycerol were incorporated as additives into polyurethanes based on a bioderived polyether polyol. Moisture-cured as well as acrylate cross-linked films of these PUs were prepared. Both materials displayed excellent thermal stability and could be cleaved in acidic solutions. In particular the highly cross-linked film produced from the acrylate endcapped polyurethanes displayed a clear tuneability of the degradation behaviour according to the amount of acetal additive incorporated. This system has the potential to be used for the selective debonding of polyurethane-based adhesives at the end of their lifetime to facilitate the recycling of expensive components and raw materials from complex devices such as consumer electronics.

Akdemir Evrendilek, Gülsün; Ardahan Üniversitesi - Mühendislik Fakültesi - Gıda Mühendisliği Bölümü - Makale, Impacts of pulsed electric fields (PEF) on physicochemical properties, bioactive compounds, and furfural and hydroxymethylfurfural (HMF) formations were quantified for sour cherry juice (SCJ). pH, titratable acidity (TA), total soluble solids (TSS), a*, b*, chroma, and total monomeric anthocyanin content (TMAC) were not significantly affected by 0–0.0341 J/L. The initial total antioxidant capacity (TAC) significantly rose with all the PEF treatments but initial citric, malic, fumaric, oxalic, succinic (−)-epicatechin, ferrulic, gallic, luteolin, p-coumaric, and o-coumaric acids, Cy-3-sop, and Cy-3-glu did not significantly degrade with no formations of furfural and HMF. The best-fit regression models explained 60.1, 39.7, and 36.3% of variation in TAC, TMAC, and TSS, respectively. Frequency exerted a greater impact than did electric field strength (EFS) on TA, pH, TSS, total color difference (TCD), hue, chroma, TMAC, TAC, sinapic, oxalic, quinic and tartaric acids, Cy-3-glu-rut, and furfural formation. 350.9 µs, 6.78 kV/cm, and 98 Hz were pointed as optimal settings.

Aim of this research was to study the evolution of heat damage, phenolic acid content and in vitro antioxidant capacity of whole meal einkorn water biscuits baked at 205 °C for increasing times (10 min steps) from 25 to 75 min. The heat damage was gauged by determining furosine, hydroxymethylfurfural (HMF), furfural and glucosylisomaltol (GLI) contents. Furosine increased up to 50 min baking, when HMF started to form; furfural augmented only after 65 min treatment, whereas GLI did not change. An unknown compound, apparently related to the severity of the heat load, aroses through the aldolic condensation of HMF with the acetone used for the extraction of phenolic acids; hence the use of acetone-based solvents in thermally processed cereal products should be avoided. The conjugated phenolic acids ferulic, vanillic, syringic, p-coumaric, p-hydroxybenzoic and syringaldehyde and the bound phenolic acids ferulic, p-coumaric, syringic, and p-hydroxybenzoic were identified in water biscuits. The stronger heating treatments led to an increase of the soluble conjugated compounds, but did not influence the bound fraction. The in vitro antioxidant capacity of water biscuits augmented significantly as baking time increased, likely for the formation of antioxidant compounds as a consequence of heat damage.

Background Mead is a traditional alcoholic beverage obtained by fermentation of mead wort and is popularly produced at home and/or in small meaderies. Different types of mead can be distinguished based on honey-to-water ratio, addition of spices and/or fruits, and the method of wort preparation. The consumption of mead has gained popularity in Europe owing to the presence of its natural and high-quality compounds. As a result, mead production has remarkably increased during the past years, and increasing attention has been paid to improve its production parameters. Scope and approach In the first part of this comprehensive review, general aspects of mead production and the characteristic parameters of alcoholic beverages, including organic acid content, pH value, ethanol content, titratable acidity, volatile acidity, and residual sugar content are discussed. In the second part, the aroma profile and sensory acceptability of mead, including parameters that might influence the characteristic aroma of mead, is presented. Key findings and conclusions The flavor of mead mainly depends on the type of honey used for fermentation, and the analysis of odorants is one of the most important criteria in the quality evaluation of mead. In addition, the presence of hydroxymethylfurfural, one of the major Maillard reaction products, and of phenolic compounds is related to the type of honey used. Furthermore, the antioxidant activity of mead significantly correlates with the type and amount of honey used for mead preparation.

Hydroxymethylfurfural (HMF) is one of the important renewable platform compounds that can be obtained from biomass feedstocks through glucose conversion catalyzed by Bronsted and Lewis acids. Howev...

Honey from two sources, Bidens pilosa and Dimocarpus longan were stored at 35, 25, or 4°C under dark or light for 3-24 months. They were evaluated for the nutrients, antioxidant activities and quality parameters required in Codex Standard. Diastase activity of examined honey was reduced to less than 8 schade unit soon after storage for 3-6 months, and its acidity was increased with long storage time at high temperature. Storage of honey at 4°C significantly diminished the loss of diastase activity and maintained the proper acidity. Hydroxymethylfurfural (HMF) content retained low level as honey was stored up to two years at either 4 or 25°C, while its content was quickly increased at 35°C. More phenolic content but less flavonoid content was found in honey after long storage time. Along with longer deposit time and higher temperature, less antioxidant activities were detected in honey, including scavenging activity of DPPH and superoxide radicals. In contrast, the reducing power was increased. Storage of honey at 35°C caused the worst impact on its quality parameters of Codex Standard, while 4oC was the best storage condition to maintain most quality parameters, nutrients and antioxidant functions. No apparent difference was found between the storage conditions under dark and light.

Oil palm biomass is readily available in Malaysia. However, its high lignin content makes it undesirable for further processing. Pretreatment is employed to reduce the amount of lignin. Many resources exist on pretreatment methods for lignocellulosic biomass, but there are few articles specifically on oil palm biomass. Therefore, this review focuses on pretreatment methods for oil palm biomass, comparing their main strengths and limitations. Furthermore, this review tabulates different pretreatment conditions utilized, combinations of pretreatment methods, the resulting yields, and the potential applicability in producing value-added products. Because the main limitation of pretreatment is the formation of toxic compounds such as furfural and hydroxymethylfurfural, this review also discusses chemical detoxification methods for oil palm biomass residues. According to this review, among all types of oil palm biomass, oil palm empty fruit brunch is the most widely studied, and alkaline pretreatment is the most popular of all pretreatment methods. Combination of pretreatment methods is suitable for biomass with greater lignin content, to increase delignification efficiency. Furthermore, a combination of overliming and activated carbon treatment removes the maximum amount of toxic by-products.

The effect of pasteurization-range heat treatment on yeast inactivation, vitamin C and the physicochemical characteristics of fresh pineapple juice were assessed. Yeast inactivation could be described by the Weibull model. The desired 6 log reduction was achieved at 63 and 65°C for 8 and 2 min, respectively. The pH, degree brix and organic acids did not change from 55 to 95°C. A significant change in fructose and glucose contents started to occur at 85°C, while sucrose hydrolysis was observed from 95°C. Likewise, hydroxymethylfurfural, one of the intermediate products of the Maillard reaction, was detected at 95°C. Little degradation of ascorbic acid, the most important nutrient in pineapple juice- was observed. Hence, a mild heat treatment of 2 min at 65°C was sufficient to inactivate yeast and to preserve the nutritional and physicochemical quality of the pineapple juice. Key words: Pineapple juice, heat treatment, yeast inactivation, physicochemical and nutritional quality.

The natural plant Cornus mas, sometimes called Cornelian cherry, has been known since ancient times and the fruit is used for various purposes. Cornus mas gives healthy fruits without the use of chemical protection, which are used as healthy, tasty and medicinal food. Cornus mas fruits can be used for eating fresh or in the form of numerous processed products: marmalade, jam, sweet, compote, syrup, juice, fruit yogurt, liqueur, wine and brandy. Due to its antioxidant, antiallergic, antimicrobial and antihistamine properties, it is increasingly used as a dietary supplement, as well as for medical purposes. Taking into account all the above, the aim of this paper is to examine samples of a mixture of honey and fresh wild Cornelian cherry, as well as a sample of honey and Cornelian cherry and determine the physical - chemical parameters: electrical conductivity, pH value, vitamin C content, HMF (hydroxy methyl furfural), as well as individual heavy metals such as iron, cadmium, lead, zinc, copper. Based on the obtained results, appropriate conclusions will be given and the possibility of registering these products as food supplements will be determined. Based on the performed analyzes, it was shown that the sample of honey and Cornelian cherry mixture had the highest pH value and electrical conductivity, and that the honey sample had the lowest value. Also, the highest value of water activity had the sample of a mixture of honey and Cornelian cherry, while the highest content of hydroxymethylfurfural had the content of Cornelian cherry. The analysis showed the absence of manganese (Mn), cadmium (Cd) and lead (Pb) in all samples, while it was shown that the highest content of Cu and Zn has the sample of Cornelian cherry 2.665 mg/kg Cu ​​and 14.41 mg/kg Zn, followed by a mixture of Cornelian cherry and honey Cu 2.778 mg/kg, Zn 14.670 mg/kg, while the honey sample has the highest Fe content of 16.72 mg/kg. This shows that the samples are rich in zinc, iron and copper, and that they are a good source for those minerals that could meet daily needs.

5‐Hydroxymethylfurfural (HMF) is a promising bio‐derived platform chemical with a broad scope of application, for example, in the production of solvents, fuels, polymers, or adhesives. The wood and foundry industries are among the largest adhesive users and currently both rely to a large extent on the use of fossil‐based binders, such as by using formaldehyde as a crosslinker in many commercial adhesive systems. The industry is thus looking for suitable alternatives to replace fossil‐based chemicals. HMF and its derivatives are considered to be key renewable reactants in adhesive systems. The core of this Review is the critical evaluation of the potential of HMF and its derivatives in adhesive systems. The technological performance was assessed in the fields of wood‐based materials, sand casting and composites. As an overall conclusion, HMF and its derivatives have a high application potential in alternative adhesives. Clearly, further research is needed to improve the performance and produce economically competitive adhesives., Sticks like glue: This Review critically assesses the role of 5‐hydroxymethylfurfural (HMF) and its derivatives as renewable key reactants in adhesives. Application fields range from wood‐based materials, sand casting, and composites. The technological performance of many HMF‐based adhesives reaches the minimum requirements, but further research on economically feasible HMF‐based resins is needed.

Catalytic strategies were developed to synthesize and release chemicals for applications in fine chemicals, such as drugs and polymers, from a biomass-derived chemical, 5-hydroxymethyl furfural (HMF). The combination of the diene and aldehyde functionalities in HMF enabled catalytic production of acetalized HMF derivatives with diol or epoxy reactants to allow reversible synthesis of norcantharimide derivatives upon Diels-Alder reaction with maleimides. Reverse-conversion of the acetal group to an aldehyde yielded mismatches of the molecular orbitals in norcantharimides to trigger retro Diels-Alder reaction at ambient temperatures and released reactants from the coupled molecules under acidic conditions. These strategies provide for the facile synthesis and controlled release of high-value chemicals.

We demonstrated the capacity of Aspergillus nidulans to degrade HMF and related compounds and analysed the genetic basis of the degradation pathway. Gene deletion mutants confirmed that AN7164 encodes a furan‐2,5‐dicarboxylic acid decarboxylase in this fungus. The AN7164 orthogroup is not found widespread across distinct fungal classes, contrary to the AN4212 orthogroup (responsible for the direct transformation of HMF) that is widespread and highly redundant., Summary Hydroxymethylfurfural (HMF) is a promising lignocellulosic‐derived source for the generation of diverse chemical building blocks constituting an alternative to fossil fuels. However, it remains unanswered if ubiquitous fungi can ensure their efficient decay, similar to that observed in highly specialised fungi. To disclose the genetic basis of HMF degradation in aspergilli, we performed a comprehensive analysis of Aspergillus nidulans ability to tolerate and to degrade HMF and its derivatives (including an HMF‐dimer). We identified the degradation pathway using a suite of metabolomics methods and showed that HMF was modified throughout sequential reactions, ultimately yielding derivatives subsequently channelled to the TCA cycle. Based on the previously revealed hmfFGH gene cluster of Cupriavidus basilensis, we combined gene expression of homologous genes in Aspergillus nidulans and functional analyses in single‐deletion mutants. Results were complemented with orthology analyses across the genomes of twenty‐five fungal species. Our results support high functional redundancy for the initial steps of the HMF degradation pathway in the majority of the analysed fungal genomes and the assignment of a single‐copy furan‐2,5‐dicarboxylic acid decarboxylase gene in A. nidulans. Collectively our data made apparent the superior capacity of aspergilli to mineralise HMF, furthering the environmental sustainability of a furan‐based chemistry.

Hydroxymethylfurfural (HMF) has been considered as one of the most promising biomass derived precursors for producing bio-based materials. Lewis acids are usually used to facilitate the isomerization of glucose to fructose in order to improve the HMF yield. In this study, glucose was converted to HMF with p-toluenesulfonic acid (pTSA) and chlorides as Bronsted and Lewis acids catalysts in the DMSO medium at 120 °C under atmospheric pressure. Kinetic modeling of the process was investigated with consideration of glucose isomerization, dehydration of fructose, rehydration of HMF and formation of humin. NH4Cl was screened as the most efficient co-catalyst for glucose conversion with HMF yield of 47%. The developed model could be well used to simulate the process with satisfying goodness of fit. The activation energies for glucose isomerization, condensation, dehydration of fructose, and rehydration of HMF were determined to be 39.8, 18.1, 55.2, and 19.0 kJ/mol, respectively. However, because the fructose concentration was very low and the reaction rate of fructose dehydration was much higher than that of glucose isomerization, a pseudo-steady state assumption could be employed, by which the observed activation energy for a lumped reaction of glucose to HMF conversion (EHMF) was determined as 45.6 kJ/mol. The developed observed kinetic model could be well used to describe the kinetics of pTSA and chloride co-catalyzed conversion of HMF. Isomerization of glucose to fructose, condensation of glucose to form humin, dehydration of fructose to form HMF, and rehydration of HMF to LA were the major reactions in the system. To improve the HMF selectivity, efforts should be made to reduce the rate of glucose condensation to form humin

Background An antioxidant formula based on peanut skins and hulls was developed and characterized for total and single polyphenols, as well as antioxidant power, considering the contribution provided by each peanut by-product. Subsequently, it was evaluated for its effect on the sensory properties and aroma stability of peanut bars over a 100-day period. To this purpose, snacks fortified, or not, with the natural additive were experimentally produced. Results Peanut hulls contributed to a greater extent than skins with respect to boosting the content of bioactives and the antioxidnt activity of the antioxidant formula, which was marked by a phenol content of (approximately 807 mg gallic acid equivalents g-1 ) and a 2,2-diphenyl-1-picrylhydrazyl activity similar to that of butylated hydroxytoluene (85.96% and 89.30%, respectively). From a sensory perspective, the incorporation of the formulation in snacks caused only a slightly stronger perception of astringent and bitter notes. Pyrazines, phenol, furan and pyrrole derivatives defined the aroma of snacks, being more abundant in fortified than in conventional samples. Such volatiles faded over storage, with different trends in the examined products. For example, the sum of 2,5-dimethylpyrazine, 2-ethylpyrazine and 2,3-dimethylpyrazine was 9.49 and 8.87 ppm at day 15; 5.57 and 7.16 ppm at day 45; and 5.03 and 4.65 ppm at day 100, respectively, in fortified and conventional snacks. Hydroxymethylfurfural decreased constantly over storage in conventional samples and only after day 45 in fortified bars. Conclusion Overall, the antioxidant formulation did not compromise the sensory desirability of peanut snacks and induced a preservative effect on their aroma, especially during the first 15 days of storage. © 2020 Society of Chemical Industry.

Honey is a viscous food, being a complex mixture of substances, among them the main components of honey are: water, minerals, sugars, organic acids, and proteins (enzymes and amino acids). Honey has in its composition compounds that can provide antioxidant properties such as phenolic compounds. This work aimed to evaluate the nutritional composition, the antioxidant capacity of bioactive compounds and to quantify proline in honeys from Pará. Chemical (moisture, protein and ash), physicochemical (hydroxymethylfurfural, reducing and non-reducing sugars, acidity, pH and electrical conductivity) and physical (color) analysis were conducted. Phenolic compounds, flavonoids, antioxidant capacity (ABTS*(+) and FRAP), and proline were also evaluated. 62.5% of Apis bee honeys were not within the moisture standards, for stingless bees, there is no official legislation. All the honeys analyzed were within the limit of the legislation in relation to the amount of HMF. High amounts of protein were found, in relation to the consulted literature. The phenolic compounds varied from 4.27 to 145.43 mg/100 g, the flavonoids varied from 2.75 to 18.76 mg/100 g, with higher values than in the literature consulted. The antioxidant capacity by ABTS*(+) and FRAP methods had excellent values, being superior to the various works with honey from Brazil and the world. The proline ranged from 6.25 to 144.70 mg/kg. With these results, it was proven that amazonian honeys have antioxidant activity, but the honey harvest needs to be improved, so as not to harm the nutritional components found in its composition.

Sugar profile and hydroxymethylfurfural (HMF) of Saudi honey were examined through high-performance liquid chromatography (HPLC) fitted with refractive index and diode array detectors. The work was designed to assess the quality of various types of blossom honey i.e. Sider (Ziziphus spina-christi), Dhuhyana (Acacia asak), Sumra (Acacia tortilis), Qatada (Acacia hamulosa), Dhurum (Lavandula dentata), Multiflora with majra (Hypoestes forskaolii), multiflora with herbs, Keena (Eucalyptus spp.) produced in the southwestern areas of the kingdom. Hierarchical cluster analysis (HCA), principal cluster analysis (PCA), and similarity and difference indices (SDI) were also applied to examine the possible grouping based on the studied quality parameters. Four main sugars (two monosaccharides i.e. fructose and glucose, two disaccharides i.e. sucrose and maltose) and HMF were investigated in two multifloral and six unifloral honey types. The average values of fructose and glucose were in the range 33.10%–44.77% and 26.68%–37.91%, respectively. The maltose was present in all types of honey and its mean values were in the range of 0.37%–2.97%, while sucrose was absent in six types of honey, 0.25% in one unifloral honey, and 3.25% in one multi-floral honey. HMF was not detected in seven types of honey but was below the limit of quantification (0.13 mg/kg) in one type of honey. PCA displayed the accumulative variance of 79.96% for the initial two PCs suggesting that honey samples were not well distinguished by their sugar profile. Based on the sucrose and HMF contents, it was concluded that all types of blossom honey from the Asir province were of the best quality in the kingdom and met the international quality parameters.

Background Sterilization of milk is aimed at killing the microorganisms present. There are three main sterilization methods commonly used in milk processing: high temperature and short time (HTST) pasteurization, ultrahigh pasteurization (UP), and ultrahigh temperature (UHT) sterilization. The Maillard reaction is of special interest in studying the effect of heat treatment on milk quality. Furfural compounds are one of the typical intermediates of the Maillard reaction, which have safety risks related to mutagenic and genotoxic effects. The furfural compounds content is directly related to the heat treatment intensity. Results The furfural compounds content was measured using high-performance liquid chromatography with ultraviolet detection in 12 min. Then, 13 levels of heat treatment intensity (combinations of temperature and time) and three levels of homogenization pressure were selected to study the change of the furfural compounds content after different processing technologies in a pilot plant. The results show a higher temperature treatment can stimulate more Maillard reaction intermediates, such as hydroxymethylfurfural and furfural. A temperature regression evaluation model and content prediction models of hydroxymethylfurfural and furfural were developed to quantify the relationship between the furfural content and heat treatment with the data from the pilot plant. Conclusion Based on the temperature evaluation model, the heating temperature of three milk products was evaluated. The homogenization pressures had little effect on the furfural content in liquid milk. The emergence of the furyl methyl ketone and methylfurfural can be detected after overprocessing of the liquid milk. © 2020 Society of Chemical Industry.

Biomass is the only renewable carbon source capable of replacing conventional production of chemicals and fuels derived from nonrenewable resources. The cellulose monomers derived from lignocellulo...

The sensory quality of fermented beverages, such as mead, is directly related to the raw material, microorganisms, and production process. The aim of this study was to evaluate the impact of Saccharomyces cerevisiae as single inoculum and co-inoculated with Meyerozyma caribbica on the physicochemical and sensory quality of mead. The meads were characterized according to their sugar, ethanol, furfural, hydroxymethylfurfural, ethyl carbamate, phenolics, volatile compounds, and sensory profile. Both starter cultures showed good fermentative capacity, resulting in beverages with 12% (w/v) alcohol content. 4-Methylumbelliferone and gallic acid were the most abundant phenolic compounds detected in both beverages. Ethyl carbamate was not detected; furfural detected below the quantification limit and 5-hydroxymethylfurfural was not higher than 0.3 mg/L. Among the identified volatile compounds, esters were the most abundant group. In general, unlike expected, the mixed inoculum resulted in a reduction of the volatile compounds. The mead produced with S. cerevisiae presented 1403.3 µg/L of esters and while mixed inoculum, 1084 µg/L. This result impacted the sensory analysis, in which the scores for flavor, aroma, and purchase intention were slightly higher for the mead produced with S. cerevisiae, although there was no statistical difference from the mixed inoculum. The results of this work indicate that further studies, such as on the adequacy of the must composition, are necessary for a better understanding of the potential of the used mixed inoculum.

Xylonic acid is a promising compound for the substitution of gluconic acid. Gluconobacter oxydans DSM 2343 has proven to be a highly potent biocatalyst for the conversion of xylose to xylonic acid. In the present study, different nitrogen sources for the growth of G. oxydans and subsequent xylonic acid production were investigated for the first time with minimal medium. Application of 0.32 g/L glutamate supplemented with 0.15 g/L ammonium sulfate as a cheap nitrogen source enabled a xylonic acid productivity of 2.92 g/(Lh) which is similar to findings involving a complex medium (3.20 g/(Lh)). The study further investigated the impact of the xylose source on the growth and production of G. oxydans. Dose-response curves confirmed that G. oxydans is mainly insensitive towards the main inhibitory compounds, acetate and hydroxymethylfurfural, up to a concentration of 5 g/L and 2.5 g/L, respectively. However, batch investigations indicated that substitution of 25 % of the pure xylose with hemicellulosic xylose resulted in a xylonic acid yield of 90 % compared to the control approach without hemicellulosic xylose. The feeding of hemicellulosic xylose in a pulsed fed-batch mode even enabled the use of 50 g/L demonstrating that the proper selection of a feeding strategy for the hemicellulosic xylose greatly improves the production of xylonic acid.

The red seaweed Gracilaria verrucosa has been used for the production of bioethanol. Pretreatment for monosaccharide production was carried out with 12% (w/v) G. verrucosa slurry and 500 mM HNO3 at 121°C for 90 min. Enzymatic hydrolysis was performed with a mixture of commercial enzymes (Cellic C-Tec 2 and Celluclast 1.5 L; 16 U/ml) at 50°C and 150 rpm for 48 h. G. verrucosa was composed of 66.9% carbohydrates. In this study, 61.0 g/L monosaccharides were obtained from 120.0 g dw/l G. verrucosa. The fermentation inhibitors such as hydroxymethylfurfural (HMF), levulinic acid, and formic acid were produced during pretreatment. Activated carbon was used to remove HMF. Wildtype and adaptively evolved Saccharomyces cerevisiae, Candida lusitaniae, and Kluyveromyces marxianus were used for fermentation to evaluate ethanol production.

Furfural production at the industrial level began 100 years ago, but its reaction conditions continue to be studied. Data on furfural production from rice husks, a by-product of the rice-peeling process, are particularly limited. This raw material must be disposed of and is usually combusted for combined heat and power generation. However, in a biorefinery framework, this material can be used to generate value-added chemicals as well as power. This study evaluated furfural production from rice husks through acid hydrolysis the potential of the remaining solid to generate power and the formation of by-products. The variables were temperature (180–230 °C), sulphuric acid concentration (0.05–3% (w/w) sulphuric acid in the solution) and time (1–105 min). The results obtained for furfural yield, solid yield and particle size distribution indicated that the best conditions are 200 °C, 0.10% (w/w) acid and 40 min, which generated a furfural production amounting to 6.0% (w/w) of the oven-dried rice husk weight (55% of the theoretical yield) and a 60% solid yield. The gross heating value of the solid fraction remained considerably constant after the treatment, and the characteristics of the ash fraction were improved. This study gives furfural yields higher than those typically achieved at the industrial level (35–50% of the theoretical yield), with hydroxymethylfurfural and acetic, formic and levulinic acids as additional products, as well as the novelty of a remaining solid in good condition for power generation, making it a successful valorisation-prior-to-combustion approach.

Bu çalışmada ‘Bayrampaşa’, ‘Sakız’ ve ‘İthal’ (Kıbrıs) olmak üzere üç farklı enginar çeşidinden enginar reçelleri üretilmiş ve reçel örnekleri fizikokimyasal özellikler (toplam kuru madde, suda çözünür kuru madde (°Briks), pH, toplam asitlik, indirgen şeker (%), toplam şeker (%), hydroxymethylfurfural, askorbik asit ve renk), antioksidan kapasitesi (DPPH, FRAP, CUPRAC), toplam fenolik bileşik içeriği ve duyusal özellikler (renk, görünüş, koku, tat, kıvam ve genel kabul edilebilirlik) bakımından incelenmiştir. ‘Bayrampaşa’ çeşidinden üretilen reçellerde a değerinin en yüksek olduğu ve dondurulmuş enginara göre 26 kat fazla olduğu belirlenmiştir. ‘Sakız’ ve ‘İthal’ enginardan üretilen reçellerin askorbik asit değerlerinin daha yüksek olduğu buna göre bu çeşitlerin reçel üretimi sırasında askorbik asit kaybına karşı daha dirençli oldukları belirlenmiştir. Reçel üretimi sonrasında antioksidan içeriğinde meydana gelen %79,25 oranındaki azalmaya karşın CUPRAC metoduna göre ‘Bayrampaşa’ çeşidinden üretilen reçel örneklerinin en yüksek antioksidan değerine sahip olduğu gözlemlenmiştir. Renk özellikleri bakımından en iyi değerlere sahip örneklerin ‘İthal’ enginardan üretilen reçeller olduğu tespit edilmiştir. Sonuç olarak iyi renk özelliklerine ve yüksek antioksidan içeriğine sahip enginar reçellerinin üretilmesi açısından ‘Bayrampaşa’ çeşidinin uygun olacağı belirlenmiştir.