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The quality evaluation and physicochemical parameters assessment of Slovak and Austrian monofloral honeys were performed. In total 65 local monofloral honeys denoted by beekeepers as acacia (n = 20), rapeseed (n = 10), linden (n = 10), honeydew (n = 6), forest (n = 12) and chestnut (n = 7) were collected. The parameters such as moisture content, water activity, electrical conductivity, pH, free acidity, and 5‑hydroxymethylfurfural (HMF) content were assessed for physicochemical characterization and comparison of all monofloral honeys. Electrical conductivity showed to be the most significant indicator for honeydew origin, that together with pH and aw led to 81.54 % correct classification of samples according to honey type using multivariate statistical analysis. In context to undesirable fermentation and spoilage, aw value below 0.600 showed to be an important control parameter that could be recommended to control especially for creamed rapeseed honeys.

This study was aimed to investigate the phenolic profile of methanolic extract of Trifolium repens L. leaves using LC–HRMS and LC–DAD and its anti--cholinesterase and anti-oxidant activities. The n-Hexane (Tr.Hex), chloroform (Tr.Chf), ethanol (Tr.Et), methanol (Tr.Cme), and aqueous (Tr.Aq) extracts were tested for anti-cholinesterases and anti-oxidant potentials. Twenty-nine phenolic compounds were quantified and identified. The highest amount present were of tyrosol (11.1 mg/g), quercetin-3-glucuronide (5.36 mg/g), formononetin-7-glucoside (5.03 mg/g), quercetin-3-O-glucoside (4.71 mg/g), 3,4-di-O-caffeoylquinic acid (4.69 mg/g), formononetin-7-glucoside-acetate (4.29 mg/g), quercetin-3-O-glucoside (4.26 mg/g), and formononetin (3.64 mg/g). Tr.Chf and Tr.Et were most active against AChE, BChE, and free radicals. Tr.Chf exhibited IC50 of 15 and 21 µg/mL against AChE and BChE, respectively. In the anti-oxidant study, Tr.Chf showed IC50 of 42 and 25 µg/mL against ABTS and DPPH radicals, respectively. The current results of anti-cholinesterase and anti-radical studies on T. repens further signify its potential application in neurodegenerative disorders.

This study evaluated for the first time the effects of microwave cooking (MWC) on phenolic, carotenoids, pigment profiles and antioxidant activity of chicory (Cichorium intybus L.) leaves grown on fresh water. The phenolic compounds, carotenoids and pigments in the leaves were extracted, analyzed and quantified using reversed-phase HPLC-DAD. Lipid peroxidation, total phenolic contents (TPC), total flavonoid contents (TFC) and radical scavenging activity (RSA) were analyzed. Results showed that 18 phenolic compounds were identified and quantified in chicory leaves. The phenolic compounds were p-hydroxybenzoic acid, quinic acid, 3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, coumaric acid, caftaric acid, chicoric acid, 3,4-di-O-caffeoylquinic acid, caffeoyl hexose, quercetin-3-feruloyl-sophoroside, 4-feruloyl quinic acid, quercetin-3-glucoside, quercetin-di-glucoside, kaempferol-3-sophoroside, luteolin-7-O-glucoside, quercetin-3-O-rutinoside, and kaempferol-3-O-glucoside. A significant increase was observed in most of the phenolic compounds during MWC. Six carotenoids and 10 pigments were also identified and quantified. All-E-lutein, all-E-β-carotene, all-E-neoxanthin and all-E-violaxanthin were the major carotenoids. A significant increase occurred in the amount of carotenoids during MWC. Among the pigments, 13-hydroxy-chlorophyll b, chlorophyll a, chlorophyll bʹ, hydroxy-chlorophyll a, and chlorophyll b were present in high amounts. Pigments contents dropped with MWC. Lipid peroxidation, TPC, and TFC were significantly increased with MWC. RSA was either increased or remained unchanged. In conclusion, cooking of chicory leaves or its pre-treatment with microwave in food industries enhanced important bioactive substances for consumer health.

The crude palm oil (CPO) and refined palm oil (PO) not only have a balance of saturated and unsaturated fatty acids but also have the highest β–carotene and vitamin E compared to others vegetable oils. A series of aliphatic aldehydes starting from hexanal to decanal was identified by LC-MS/MS and quantified as DNPH derivatives. In addition, the total amount of carbonyls was determined based on the calibration with hexanal. Looking at the kinetic profile of the carbonyl formation in crude palm oil and refined palm oil, both of the oils were still stable until 10 h of oxidation with the Ranzimat at 120 °C. The analytical method for quantifying the vitamin E and β–carotene are quick, reliable, precise, economical and suitable for the routine analysis. For both analyses, a simple dilution of the oil was necessary. The quantitative analysis showed that β–carotene in the oxidized crude palm oil decreased from 2.34 mg/g to 0.33mg/g within 7.5 h of oxidation. However, after 7.5 h, no more β–carotene was detected. In addition, β–carotene was not detected in refined palm oil. The HPLC-DAD method developed for the β–carotene in the crude palm oil was validated. The coefficient of determination (0.999) of the linear regression indicates a good correlation between the peak area and the amount of β–carotene. The linearity of the β–carotene analysis was tested in the range 0.00078–0.05 μg/cm3. The limit of detection (LOD) was 2.65 μg/cm3 and the limit of quantification (LOQ) was 8.83 μg/cm3 for β–carotene. Vitamin E in both refined and crude palm oil, δ–tocotrienol and γ–tocotrienol, have the long shelf life compared to α–tocopherol and γ–tocopherol. The δ–tocotrienol is degraded slowly and can be found even after 15 h of oxidation with 0.035 mg/g remaining in the oxidized crude palm oil. However, in refined palm oil, the δ–tocotrienol could be determined until 11 h of oxidation with 0.49 mg/g.

A relation between oil uptake and cancer as well as induction of hepatic inflammation was shown earlier. It is discussed that the main oil oxidation products—hydroperoxides and carbonyls—might be the reason for the mentioned diseases. In this manuscript quantitative determination of aldehydes which are formed during oxidation of triolein—as a model substance—using the Rancimat 679 is described. The oxidation of 11 g of triolein is carried out at 120 °C sparging air with a flow of 20 dm3/h for 10 h. A series of aliphatic aldehydes starting from hexanal to decanal as well as decenal was identified by LC–MS/MS and quantified as DNPH derivatives. In addition, the total amount of carbonyls was determined. Based on the calibration with hexanal, all other dominant substances were in the similar concentration range with maximum concentrations of 1.6 µmol/cm3 of hexanal, 2.3 µmol/cm3 of heptanal, 2.5 µmol/cm3 of octanal, 3.2 µmol/cm3 of nonanal, 4.0 µmol/cm3 of decanal after 6 h. The total amount of carbonyls reached a maximum after 6 h being 27 µmol/cm3 for triolein without antioxidant. The results of this investigation will be a basis for further toxicological studies on oxidized oils. Graphical abstract

Lipid oxidation during heating started at the allylic position of the double bond of unsaturated fatty acids. Primary lipid oxidation which was produced during heating are generally unstable and directly decompose into secondary oxidation products. The oxidative and thermal stability of Rapeseed oil was evaluated using Rancimat 679. Oil samples were heated at 120oC for 10 hours which are taken started from 5, 6, 6.5, 7, 7.5, 8, 9 and 10 hours. Derivatization with DNPH eluted with a mixture of methanol (60%) and water (40%). The aldehydes are analysed by High Performance Liquid Chromatography- Diode Array Detection (HPLC-DAD) after derivatisation with DNPH and identified by high-resolution MS using an orbitrap-based mass spectrometer. HPLC is the suitable method to investigate the non-volatile aldehydes formed by decomposition of hydroperoxides. The result of this oxidation process were described that the maximum point of the oil oxidation was at 9 hours which peak area 378. For oxidation process at the 10 hours the area peak is decreased which point 344.

There is ample evidence that polyphenols are important natural substances with pronounced antioxidative properties. This study aimed to develop a fast and reliable method to determine total polyphenol content (TPC) in foodstuffs and human samples. The microtitration format offers the advantage of low sample volumes in the microlitre range, facilitating high-throughput screening with 40 samples simultaneously. We accordingly adjusted the so-called Folin&ndash, Ciocalteu method to a microtitre format (polyphenols microtitre&mdash, PPm) with 90% reduction of reagents. The assay was standardized with gallic acid in the range between 0.1 and 3 mM, using a 20 &micro, L sample volume. The intra-assay coefficient of variation (CV) was less than 5%, and inter-assay CV was in the range of 10%. Wavelength was measured at 766 nm after two hours of incubation. This micromethod correlates significantly with both the classical Folin&ndash, Ciocalteu method and High-Performance Thin-Layer Chromatography (HPTLC) (r2 = 0.9829). We further observed a significant correlation between PPm and total antioxidants (r2 = 0.918). The highest polyphenol concentrations were obtained for red, blue, and black fruits, vegetables, and juices. Extracts of red grapes could be harvested almost sugar free and might serve as a basis for polyphenol supplementation. Beer, flour, and bread contained polyphenol concentrations sufficient to meet the minimal daily requirement. We conclude that PPm is a sensitive and reliable method that detects polyphenols even in samples diluted 10-fold. The literature strongly recommends further investigations on the effects of polyphenol uptake on human and animal health.

Healthy food is a result of huge efforts to produce safe products. This starts with the supply of safe raw materials which are handled with the support of a series of safety protocols. These include the use of low storage temperatures, clean working environment, sufficiently high cooking temperatures, and safe and hygienic logistic measures. The consumer himself can contribute to the safety by a few simple measures to keep the food at home safe. However, there are more points that have to be considered with safe foods. These include the presence of inherent toxic substances that might be present in the raw materials (e.g. arsenic in drinking water, alkaloids in plant foods, carcinogenic substances formed during heating). In addition to these basic food related issues the uptake of food – which is also a social event – can contribute to the well-being which is also part of a healthy life.

The non-polar heterocyclic aromatic amines (HAAs) are formed as pyrolysis products of amino acids at higher temperatures. Green coffee beans were roasted at 240 °C from 5 to 14.5 min (four levels). Solid-phase extraction coupled to high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was used for identification and quantification of five HAAs (Glu-P 2, Glu-P 1, Phe-P 1, AαC, and MeAαC) in roasted coffee. The excitation and emission wavelength program was optimized for non-polar HAAs. The analytes were eluted with eluent A (76% water, 14% acetonitrile, 8% methanol, and 2% acetic acid; pH = 5) and B (acetonitrile) in gradient mode. The limits of detection for non-polar HAAs were in the range of 0.21–0.51 ng/g, the limits of quantification from 0.38 to 0.93 ng/g with a recovery of 40–56%. From the tested HAAs, only AαC was present in roasted coffee; Glu-P 2, Glu-P 1, Phe-P 1, and MeAαC were not found in any coffee sample.

The mitigation of furfuryl alcohol, 5-hydroxymethylfurfural, 2-furoic acid, and 5-hydroxymethyl 2-furoic acid was conducted in two dry model systems mimicking coffee and an actual coffee system by incorporating 14 chemicals, that are categorized to phenolic acids, flavonoids, non-phenolic antioxidants, and non-antioxidant agents. Mitigation effects were determined as the decrease in the levels of the studied furan derivatives after the systems went through a controlled roasting process. Strong mitigation effects in the dry model systems were observed after the application of phenolic acids, quinic acid or EDTA. The mitigation effects of phenolic acids and flavonoids depended on the number and availability of phenolic hydroxyl groups. Certain agents exhibited a furan derivative-specific reducing effect while most of them showed a generalized effect. The mitigation efficacy decreased with the increasing complexity of the tested systems. In the coffee system, mitigation effects were almost completely lost in comparison with dry model systems. Still, taurine and sodium sulfite exerted the strongest mitigation effect in the coffee system.

Sea buckthorn (Hippophae L.) is a valuable, multipurpose plant extensively grown in Asia, Europe and Canada. In order to use it in the best way for products of human nutrition, it is necessary to recognize its positive aspects and to eliminate the negative ones. The exceptional value of sea buckthorn can be seen in the presence of both lipophilic antioxidants (mainly carotenoids and tocopherols) and hydrophilic antioxidants (flavonoids, tannins, phenolic acids, ascorbic acid) in remarkably high quantities. Some of the main nutrients, especially lipids of advantageous fatty acid composition, contribute to nutritional benefits of sea buckthorn products for a consumer as well. This review article focuses, besides the above mentioned compounds and vitamins, also on other important components, such as sugars, sugar derivatives, fibre, organic acids, proteins, amino acids and mineral elements. The article also deals with the effects of sea buckthorn components on the course of non-enzymatic browning of food and in vivo glycation. In addition, sensory perception of sea buckthorn and its constituents from the consumers point of view is discussed.

The simultaneous quantification of two potential genotoxic hydroxymethyl furan derivatives in coffee (furfuryl alcohol and 5‐hydroxymethylfurfural) alongside their carboxylic acid derivatives (2‐furoic acid and 5‐hydroxymethyl furoic acid, respectively) was carried out. Their extraction from ground roasted coffee using sonication, simple shaking or heat‐assisted shaking lead to similar results. A minimum of 97.3% of the four furan derivatives were extracted during the first extraction cycle using water, whereas methanol showed considerably lower extraction efficiency. A simple high‐performance liquid chromatography method coupled with diode array detection was developed for the simultaneous determination and was applied to roasted coffee extracts or brews. No sample pre‐treatment except for centrifugation was needed. The diode array detector was used to assess the purity of the peaks of interest in analyzed samples against authentic standards. The linearity according to Mandel, accuracy (recovery ≥ 89.9%) and precision (inter‐ and intraday relative standard deviation ≤ 4.5%) were checked. The values for the limit of detection and quantification ranged within 0.11–0.76 and 0.35–2.55 μg/mL, respectively. Filtered and espresso brews were analyzed for the four furan derivatives where furfuryl alcohol showed double the concentration of 5‐hydroxymethylfurfural and about ten times the concentrations of 2‐furoic acid or 5‐hydroxymethyl furoic acid.

During processing of foods a series of health compromising substances can be formed. This is normally the case during heating. The compounds that are discussed in this chapter are heterocyclic amines, chloropropanols, furans, acrylamide, and polycyclic aromatic hydrocarbons (PAHs). These groups of compounds have a completely different origin, being a result of heat induced reactions. Heterocyclic amines are mainly formed in meat, chloropropanols in practically any food containing chloride and lipids, furans in many carbohydrate containing foods but also from lipids and ascorbic acid, acrylamide in starchy foods with amino acids presence, and PAHs in processed foods. All these compounds have a carcinogenic potential but they can also show acute toxicity.

Recently, furfuryl alcohol (FFA) was labelled a human potential carcinogen (group 2B) by the International Agency for Research on Cancer. Its alimentary exposure is mostly from coffee since in any other foods the concentrations are significantly lower. The various storage conditions of roasted coffee, the different brewing techniques applied and the bioaccessibility after ingestion are potential parameters that might alter the exposure to FFA from coffee. An 8 weeks stability study at varying temperatures showed that FFA is stable in the ground coffee matrix. Moreover, different brewing techniques extracted different amounts of FFA and affected its final concentration. The evaluation of the relative exposure to four furans (FFA, 5-hydroxymethyl-furaldehyde, 2-furoic acid, and 5-hydroxymethyl-2-furoic acid) revealed that FFA amounts were at least 2-fold the amounts of other studied furans in the same brew. A 22-fold variation in the concentration of the four furans in brews prepared using different coffee grounds and brewing techniques could be observed. 90% of the four furans were extracted by the first 25-30% fraction of the filter brew. A significant decrease of FFA is observed after stressing with simulated gastric fluid. However, this decrease could not be reproduced when mimicking a regular coffee ingestion situation.

Summary Nitric oxide (NO)-inhibitory and antioxidative activities of tilapia hydrolysates were prepared using ultrasound pretreatment at 70 W for 30 and 45 min, respectively, followed by Flavourzyme hydrolysis for 1 h. Both hydrolysates were fractionated using size exclusion chromatography on Sephadex G-25 column and purified by RP-HPLC. The amino acid sequence of the most potent and purified fractions was determined using LC/MS/MS. The antioxidant peptide (KAFAVIDQDKSGFIEEDELKLFLQNFSAGARAGDSDGDGKIGVDEFAALVK, MW: 6334.49 KDa) and NO-inhibitory peptide (AFAVIDQDKSGFIEEDELKLFLQNFSAGARAGDSDGDGKIGVDEFAALVK, MW: 6309.49 Da) produced no cytotoxicity in RAW264.7 macrophage cell lines at the concentration of 100 mg mL−1. The purified peptides at the concentration 100 μg mL−1 possessed antioxidative and NO-inhibitory activities 83.0 ± 1.1% and 40.9 ± 0.2%, respectively, which were about 100 times those of their counterpart crude hydrolysates.

To reach an integrated sustainable production site, it is important to analyse effects of technology changes. A “brewery model” has been developed which allows process modelling of a brewing facility. Besides the comparison of specific demand figures, it allows a holistic view of the production site and most importantly the modelling of energy demand profiles. Energy demand profiles in brewing vary significantly based on the chosen technology set. Furthermore they are notably influenced by production planning, heat exchanger surfaces and heat supply management. A reduction in energy intensity in the brewhouse processes will lead to the possibility to design heat supply equipment at lower capacity. The mashing process is an important candidate in considerations for heat recovery and low temperature heat supply. New temperature profiles in mashing can improve processing time, quality of the produced wort as well as enable the integration of low temperature heat in a better way.

Summary Ultrasound was incorporated to processing of fish protein hydrolysate to facilitate homogenate pretreatment and enzymatic hydrolysis of tilapia (Oreochromis niloticus) muscle protein. Their effects on Flavourzyme hydrolysis and biological activities of the tilapia hydrolysate were examined. The ultrasound-assisted hydrolysis caused reduction in degree of hydrolysis ranging from 23% to 35% relative to that of the conventional process. The 70 W ultrasound-assisted hydrolysis process increased DPPH radical-scavenging activity and reducing power of tilapia hydrolysate prepared from the non-pretreatment homogenate by 33% and 45%, respectively. All hydrolysates have no cytotoxicity on RAW264.7 cell lines at the maximum concentration of 20 mg protein mL−1. The 70 W ultrasound pretreatment at 30 and 45 min combined with conventional hydrolysis is the suitable condition for producing tilapia hydrolysate with nitric oxide inhibitory and antioxidative activities on RAW264.7 cell lines, respectively. As a result, ultrasound could be applied to enzymatic protein hydrolysis either as pretreatment or during the hydrolysis.

The combination of a laccase–hydroxybenzotriazole (HBT) mediator system with/without cellobiose dehydrogenase (CDH) or an additional Fenton reaction step for the elimination and/or detoxification of phenolic compounds in dry olive mill residues (DOR) and liquid olive mill wastewaters (OMW) was evaluated. The laccase–HBT–CDH and laccase–HBT–CDH–Fenton system were the most effective, removing at least 69 and 72 % of phenolic compounds from a total of 698 and 683 mg in OMW and DOR, respectively, in 12 h. The efficient removal of phenolic compounds was also accompanied by >80 % reduction in biochemical oxygen demand and chemical oxygen demand in both DOR and OMW. Microbial community analysis using single-strand conformation polymorphism (SSCP) gels showed that biogas reactors supplemented with untreated and laccase–HBT–CDH–Fenton-treated DOR and OMW strongly inhibited growth of microorganisms. In contrast, the laccase–HBT- and laccase–HBT–CDH-pretreated OMW and DOR were detoxified as evidenced by SSCP analysis, which also indicated a distinct sensitivity of the individual members of the anaerobic population toward the toxicants. Further, although the laccase–HBT–CDH–Fenton system was effective in bleaching and removing phenolic compounds in both OMW and DOR, it was not able to support methane production. However, laccase–HBT and laccase–HBT–CDH indeed supported biogas production. This study therefore shows that the laccase–HBT–CDH system has a potential for the detoxification of olive mill residues, which can be potentially used as substrates for downstream processes.

Antioxidant properties and composition of phenolic active constituents in wood betony (Stachys officinalis) extracts, successively isolated with acetone and methanol, were studied by the batch and the on-line radical scavenging assays. The content of total phenolics was higher in acetone extract (the yield 5.6%) by 26% than in methanol extract (the yield 18.6%), however the latter extract was stronger radical scavenger in DPPH and ABTS+ assays: 714 ± 83 μM vs 558 ± 33 μM trolox equivalents per g of dry extract. The main compounds possessing antioxidant activity in the extracts of woody betony assessed by the on-line HPLC–DPPH method and preliminary identified by HPLC/UV/MS and HPTLC analysis were chlorogenic acid, phenylethanoid glycosides and hydroxycinnamic acid derivative.

The antioxidant potential of Gratiola officinalis was evaluated by the off-line and on-line HPLC/UV/DPPH radical scavenging assays, phytochemical composition was analyzed by LC/MS. On-line method was validated by using reference antioxidants and linear dependence was found between their concentration and radical scavenging peak area. Radical scavenging capacity (RSC) of methanol and acetone extracts expressed in their concentration required to scavenge 50% of DPPH• was 0.10% and 0.13%, respectively; the RSC in ABTS•+ assay was 1093 ± 104 and 746 ± 18 μM of trolox equivalents in 1 g, respectively. Good correlation was observed between total amount of phenolic compounds and RSC. Preliminary HPLC/UV/MS analysis revealed that the main compounds possessing antioxidant activity in the extracts might be phenylpropanoid glycosides; UPLC/UV/ESI-QTOF-MS analysis suggested 15 structures: 2,5-dihydroxy-p-benzenediacetic and caffeic acids, apigenin 6,8-di-C-β- d -glucopyranoside (vicenin-2), apigenin 8-C-α- l -arabinoside 6-C-β- d -glucoside, (shaftoside), forsythoside B, arenarioside, verbascoside (acteoside), amioside, quercetin-6-O-(2-O-acetyl-glucopyranosyl)-glucopyranoside, isoverbascoside, quercetin glucuronide, linariifolioside, methoxy luteolin-7-O-(6-O-acetyl-glucopyranosyl)-glucopyranoside, methoxy luteolin-glucuronide and luteolin glucuronide.

β-Carotene is one of the most important fat soluble pigments with well-known antioxidant and pro-vitamin A activity. It is used in industries as a food colorant and a source of vitamin A. The thermal induced degradation during processing of wide varieties of carotenoid-rich foods leads to color and properties losses. The thermal stability of edible oils is thus of great importance to food manufacturers. Corn oil, rapeseed, and sunflower oils were fortified with 50–300 μg/g of β-carotene and oxidized using a Rancimat apparatus (air flow rate 20 L/h) at 110 °C for 14 h. β-Carotene degradation was measured using high performance thin layer chromatography and confirmed by HPLC–DAD–MS. Triacylglycerols and polar compounds (PC) were determined using LC–ESI–MS. Results showed that most of the β-carotene was degraded during the first 5 h of the thermal oxidation. It was found that the addition of β-carotene produces significant effects (P

Antioxidant activity and the composition of antioxidatively active constituents in swallow-wort (Vincetoxicum lutea L.) were investigated in order to assess the prospects for future studies and applications of this plant in the preparation of bioactive functional ingredients. Total extract yield obtained from V. lutea by subsequent extraction with acetone and methanol was 33.34%; acetone soluble fraction constituted 24.19% while methanol additionally extracted 9.24% of more polar substances. The radical scavenging capacity of the acetone fraction was higher than that of the methanol fraction; total content of phenolics in acetone and methanol extracts was 131.8 ± 11.6 and 86.0 ± 8.6 mg gallic acid equivalents (GAE) in 1 g of dry extract, respectively. The composition was studied by HPLC and HPTLC methods by using UV and MS detectors and 8 compounds were identified. One of the major antioxidants in V. lutea extracts was chlorogenic acid.

Ammonia caramels are the most common antioxidant colour agent used in bakery formulations, although their high sugars content. An alternative could be coffee melanoidins, which are brown coloured compounds with antioxidant properties, readily available from instant coffee. However, high caffeine content is limiting its direct application. To evaluate the possibility of obtaining coloured melanoidin-rich, sugars- and caffeine-poor fractions from instant coffee, in this work, simple procedures based on their ethanol insolubility (fraction EtPp) or retention by ultrafiltration (fraction HWSn) were exploited. Melanoidins incorporation into biscuits formulation (amounts of 1, 5 and 10% w/w related to flour content) resulted in acceptable coloured products with higher antioxidant activity. The biscuits supplemented with 1% EtPp or HWSn had a low caffeine content. The caffeine of one espresso coffee was equivalent to 130 biscuits containing EtPp and 31 biscuits containing HWSn. Besides, both fractions did not promote extra formation of acrylamide or 5-hydroxymethylfurfural during baking.

5-Hydroxymethylfurfural (HMF) and furfuryl alcohol (FFA) are present in numerous foodstuffs at high levels. FFA is also used for the production of polymers. Both compounds had demonstrated some evidence of carcinogenic activity in 2-year bioassays. We tested these compounds and four congeners for mutagenicity in Salmonella typhimurium TA100 and TA100-derived strains expressing human or rodent sulphotransferases (SULTs). 5-Hydroxymethylfuroic acid, a metabolite of HMF, was not mutagenic in any strain. 3-Hydroxymethylfuran was weakly mutagenic in all strains independently of SULT expression. HMF, 2,5-(bishydroxymethyl)furan (metabolite of HMF), FFA and 5-methyl-FFA were inactive in TA100 but strongly mutagenic when human SULT1C2 was expressed. This form has been detected in ovary, kidney and foetal tissues. Human SULT1A1, SULT1A2 and SULT1A3 as well as murine Sult1a1 and Sult1d1 also activated some hydroxymethyl-substituted furans to varying degrees. Whereas chemically synthesised 5-sulphooxymethylfurfural was mutagenic in TA100, furfuryl sulphate was bacteriotoxic, only leading to marginal increases in the number of revertants. Furfuryl acetate, an uncharged ester of FFA, used as fragrance and food flavouring, was clearly mutagenic. We determined half-life times of 120 min, 20 s and 10 h, respectively, for 5-sulphooxymethylfurfural, furfuryl sulphate and furfuryl acetate at 37°C in water. It is likely that the short lifespan of furfuryl sulphate, together with its charge, led to insufficient penetration of the bacteria when added externally, although it was mutagenic when generated by appropriate SULTs from FFA within the cell.

Carotenoids (β-carotene and astaxanthin) were added to refined olive oils and oxidised in a Rancimat at 110 °C for 1–14 h. Triacylglycerols (TAGs) were found to oxidise much faster in the presence of β-carotene and slower in the presence of astaxanthin, while β-carotene degradation was much faster than that of astaxanthin. Astaxanthin was found to protect the TAGs of olive oils for up to 10 h of thermal treatment. Both carotenoids were found to significantly increase peroxide values at higher exposure time. A total of 11 TAGs oxidised species were identified, including a new class of oxidised species (hydroxy epidioxides), reported here for the first time. The effect of carotenoids on the formation of oxidised TAGs illustrates that the pro-oxidant action of β-carotene was much stronger than that of astaxanthin. We suggest that astaxanthin could be used as an alternative to β-carotene in edible oils fortification and as a food colourant.

The anthocyanin composition of red grape varieties Vranec, Cabernet Sauvignon, Merlot and Pinot Noir was determined analyzing the skin extracts of the grape berries. The relative content of the identified anthocyanins was calculated and the obtained anthocyanic profiles were compared in terms of acylation and anthocyanidin distribution. The predominant anthocyanin in all varieties was malvidin-3-glucoside ranging from 35.8% in Cabernet Sauvignon to 67.1% in Pinot Noir. Vranec variety was characterized by high proportions of coumaroyl derivatives (22%) and peonidins (13%). The most pronounced difference among the studied grape cultivars was the relative amount of acetate derivatives accounting 35% in Cabernet Sauvignon, 22% in Merlot and 9% in Vranec. Different relationships among the anthocyanin groups of compounds were calculated and considered as parameters for differentiation of the cultivars. The relationship between coumarates and acetates in Vranec was significantly higher compared with Merlot and Cabernet Sauvignon with obtained values of 2.37 versus 0.63 and 0.56, respectively. Moreover, the ratio between delphinidins and peonidins allows clear discrimination between the studied grape cultivars showing the greatest difference.

A liquid chromatographic method with UV detection was developed to analyse 5-hydroxymethyl-2-furfural and its main metabolite 5-hydroxymethyl-2-furoic acid in urine. For the analysis on a reversed phase column was used with 5% methanol in water and 5 mM tetramethylammoniumhydrogen sulphate as ion-pair reagent as eluent. The detection was done at the UV absorption maximum of HMFA at 255 nm. The limit of quantification for HMFA was 7 mg/L with a recovery of 89%. For sample preparation the urine was centrifuged and the supernatant diluted with water. Three hundred samples of human urine were analysed. The concentration of HMFA was in the range of 0–100 mg/L with most of the samples around 10 mg/L.

RP HPLC method coupled to ESI-MS was used for the analysis and characterization of the oxidation of model triacylglycerols (TAGs) in presence of β-carotene, β-Carotene was added to the TAGs and oxidized in the Rancimat at 110°C. The samples were separated isocratically using a mixture of isopropanol with methanol and a Phenomenex C18 column. β-Carotene degradation was measured using high performance TLC. We found that β-carotene plays an important role during the thermal degradation of high oleic acid model TAGs. Half of the β-carotene was degraded before 3 h of thermal treatment. β-Carotene significantly increases the peroxide value of the TAGs after the third hour, suggesting a pro-oxidant action. However, different TAGs show different activity toward thermal treatment and β-carotene. The LLL was found to be less stable, OLL and OLO were stable till 10 and 12 h respectively, while POO, OOO, and OSO were the stable TAGs till 14 h. In TAGs, replacing linoleic acid by oleic acid, the stability of the corresponding TAG was found to increase by 2 h. A new class of oxidized TAGs was reported for the first time, together with previously reported species. The proposed mechanism of formation and identification of the newly identified species have been explained. Among the oxidized species of TAGs, mono-hydroperoxides, bis-hydroperoxides, epoxy-epidioxides, and epoxides were the major compounds identified.

A simple, fast and reproducible reversed-phase high performance liquid chromatography (HPLC) method coupled to electrospray ionization mass spectrometry (ESI-MS) for the analysis of triacylglycerols (TAGs) species in the commercial edible oils has been developed. The TAGs species were separated using isocratic 18% isopropanol in methanol and a Phenomenex C18 column. The ESI-MS conditions were optimized using flow injection analysis of standard TAG. Fifteen, fourteen, and sixteen TAGs were separated and identified in corn oil, rapeseed oil, and sunflower oil, respectively. The presence of intense protonated molecular (M + H⁺), ammonium (M + ${\rm NH}_{4}^{ + } $), and sodium (M + Na⁺) adducts ions and their respective diacylglycerols ions in the ESI-MS spectra showed correct identification of TAGs. Some minor potassium adducts (M + K⁺) were also found. In addition, the identity of the fatty acid, position of each fatty acid, and the location of the double bond in the fatty acid moiety were explained. It was found that this isocratic method is useful for fast screening and identification of triacylglycerols in lipids.

Carotenoids are important pigments found in foods and biological samples. Among carotenoids, β-carotene is the major carotenoid present in vegetable oils. It plays an important role in the thermal stability of the vegetable oil. We established a simple, precise, specific, sensitive, repeatable, and accurate HPTLC method for the analysis of β-carotene in fortified vegetable oils and assessment of its degradation. Analysis was performed on silica gel HPTLC plates with petroleum ether-hexane-acetone 2:3:1 ( v/v ) as mobile phase and densitometric detection. The R F of β-carotene was 0.91 and regression analysis showed response was a linear function quantification of amount of β-carotene in the range 100–600 ng ( r 2 = 0.99991). The limits of detection and quantification were 0.11 and 0.37 ng, respectively. The thermal degradation (1–5 h at 100°C) of β-carotene in fortified sunflower oil was studied. It was observed that this HPTLC method could be used for efficient analysis and monitoring of the degradation ...

The potential of laccase-generated tetramethoxy azobismethylene quinone (TMAMQ) for measuring antioxidant activity of a wide range of structurally diverse molecules present in food and humans was investigated for the first time. All the tested antioxidants including simple phenolics, polyphenols and vitamins quenched TMAMQ. The antioxidant activity of phenolics and polyphenolics depended on the position and number of hydroxyl groups on the benzene ring. Equally interesting was the ability of amino acids like cysteine, tryptophan and methionine as well as peptides (glutathione) and proteins (albumin) to quench TMAMQ, demonstrating the great potential of TMAMQ for analysis of antioxidant activity of serum samples. Further, TMAMQ is promising is a more reliable tool for measuring antioxidant activity of amino acids when considering conflicting reports on antioxidant activity of some of the amino acids. The extracts from various food samples showed varying antioxidant activity with highest for spinach (4.36 mg methanol extract/mmol TMAMQ) followed by kiwi (13.95 mg methanol extract/mmol TMAMQ) and lettuce (40 mg methanol extract/mmol TMAMQ). The use of the laccase generated TMAMQ can be exploited for the development of laccase based biosensors for complex and coloured samples thereby facilitating online monitoring of antioxidants in food, cosmetic and health industries.

Attractive color is one of the most important sensory characteristics of fruit and berry products, and elderberry juice is widely used as natural colorant. When pectinase preparations were used in the production of elderberry juice for clarification, a concomitant decrease of anthocyanins and thus a color loss were observed. This paper demonstrates that this is due to side glycosidase activities contained in commercial pectinase preparations from Aspergillus sp. Using LC-MS, sequential deglycosylation of cyanidin-3-sambubioside, cy-3-glucoside, cy-3-sambubioside-5-glucoside, and cy-3,5-diglucoside was found to be catalyzed by specific glycosidases contained in the pectinase preparations. There was no big difference in the deglycosylation rate between monoglucosidic or diglucosidic anthocyanins. However, the degradation rate was decreased when rutinose was attached to cyanidin, whereas the structure of the aglycone itself had almost no influence. Pure beta-glucosidases from Agrobacterium species and Aspergillus niger and the beta-glucosidase N188 from A. niger did not show any conversion of anthocyanins, indicating the presence of specific glycosidases. Thus, an activity gel based assay was developed to detect anthocyanin-specific glycosidase activity in enzyme preparations, and according to LC-MS peptide mass mapping of digested bands, homologies to a beta-glucosidase from Aspergillus kawachii were found.

A novel antioxidant activity assay was developed using laccase-oxidized phenolics. In a three-step approach, phenolic compounds were first oxidized by laccase. Laccase was then inhibited using 80% (v/v) methanol which also stabilized the oxidized phenolics which were then used to measure antioxidant activities of ascorbic acid and Trolox. From a number of laccase-oxidized phenolics screened for potential use in the measurement of antioxidant activities, syringaldazine emerged the best, giving results comparable to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, which is currently used in conventional methods. Like DPPH radicals, two moles of stoichiometric oxidized syringaldazine were reduced by one mole of either ascorbic acid or Trolox. For the first time we show that antioxidant activity can be correlated to oxygen consumption by laccase. Reduction of one molecule of oxygen corresponded to oxidation of four molecules of syringaldazine which in turn is reduced by two molecules of Trolox or ascorbic acid. This study therefore demonstrates the great potential of using laccase-oxidized syringaldazine for the measurement of antioxidant activity.

Here we report for the first time that L-amino acid oxidase (LAAO), a major component of snake venom, induces apoptosis in yeast. The causative agent for induction of apoptosis has been shown to be hydrogen peroxide, produced by the enzymatic activity of LAAO. However, the addition of catalase, a specific hydrogen peroxide scavenger, does not prevent cell demise completely. Intriguingly, depletion of leucine from the medium by LAAO and the interaction of LAAO with yeast cells are shown to be the major factors responsible for cell demise in the presence of catalase.

2,5-Dimethylfuran (DMF) and furfuryl alcohol (FFA) are two substituted furans that are formed during the processing of foods and have also been used as food flavorings. DMF and FFA are proposed to be bioactivated by human sulfotransferases (SULTs) which are not expressed in conventional cell lines used for genotoxicity testing. Therefore, in addition to the standard V79 cell line, we used a transfected V79 derived cell line co-expressing human cytochrome P450 (CYP) 2E1 and human SULT1A1 to assess the genotoxicity of DMF and FFA. The alkaline single cell gel electrophoresis (SCGE) assay was used to detect DNA damage in the form of single strand breaks and alkali-labile sites after exposure to DMF (0.5h; 0.5, 1, 1.5 or 2mM) or FFA (3h; 1, 3, 6 or 15mM). DMF induced DNA damage in V79 cells in a concentration-dependent manner irrespective of the expression of human CYP2E1 and SULT1A1. Almost no increase in the level of DNA damage was detected after exposure to FFA, except for a weak effect at the highest concentration in the transfected cell line. The results suggest that DNA damage in V79 cells from exposure to DMF detected by the alkaline SCGE assay is independent of human CYP2E1 and SULT1A1, and the genotoxic effect of FFA, as assessed by SCGE, is minimal in V79 cells.

Heterocyclic aromatic amines are formed in protein and amino acid-rich foods at temperatures above 150 degrees C. Of more than twenty heterocyclic aromatic amines identified ten have been shown to have carcinogenic potential. As nutritional hazards, their reliable determination in prepared food, their uptake and elimination in living organisms, including humans, and assessment of associated risks are important food-safety issues. The concentration in foods is normally in the low ng g(-1) range, which poses a challenge to the analytical chemist. Because of the complex nature of food matrixes, clean-up and enrichment of the extracts are also complex, usually involving both cation-exchange (propylsulfonic acid silica gel, PRS) and reversed-phase purification. The application of novel solid-phase extraction cartridges with a wettable apolar phase combined with cation-exchange characteristics simplified this process--both the polar and apolar heterocyclic aromatic amines were recovered in one fraction. Copper phthalocyanine trisulfonate bonded to cotton ("blue cotton") or rayon, and molecular imprinted polymers have also been successfully used for one-step sample clean-up. For analysis of the heterocyclic aromatic amines, liquid chromatography with base-deactivated reversed-phase columns has been used, and, recently, semi-micro and capillary columns have been introduced. The photometric, fluorimetric, or electrochemical detectors used previously have been replaced by mass spectrometers. Increased specificity and sub-ppb sensitivities have been achieved by the use of the selected-reaction-monitoring mode of detection of advanced MS instrumentation, for example the triple quadrupole and Q-TOF instrument combination. Gas chromatography, also with mass-selective detection, has been used for specific applications; the extra derivatization step needed for volatilization has been balanced by the higher chromatographic resolution.

Enzymatic coating of functionalized cellulose fibers with catechol was performed in the presence of Trametes hirsuta laccase. Cellulose functionalization was done by covalent fixation of aromatic amines onto the cellulose surface using a dyeing procedure with C.I. Reactive Black 5 (RB5) followed by reduction with sodium hydrosulfite. Cellulase enzymes were used on coated and control samples to obtain the analytes linked with the soluble sugars in solution, to prove the reaction concepts described in this paper. Hydrolyzed coated-cellulose showed lower concentration of reducing sugars (1188 mg/L) than control samples (2011 mg/L). The structures of these compounds were checked by LC/MS analysis confirming the presence of functionalized glucose and cellobiose units coupled to poly(catechol) molecules (m/z 580 and m/z 633). Alkali extraction method showed to be very promising to coat cellulose fibers with phenols in the presence of enzymes, at mild conditions of temperature and pH.

The formation of 5-hydroxymethyl-2-furfural (HMF) and 5-hydroxymethyl-2-furoic acid (HMFA) during roasting of coffee was studied. At 240 degrees C the maximum concentration of HMF occurs after 3 min with a quick degradation up to 10 min when most of the HMF has disappeared again. Similar to 5-hydroxymethyl-furfural, HMFA is formed in coffee but not in a model system consisting of sucrose, alanine with or without chlorogenic acid. It was shown that HMFA is produced from different precursors than HMF namely glyceraldehyde and pyruvate. The comparison of the laboratory scale roasting with industrial roasting showed that 5-hydroxymethyl-furfural decreases with a higher degree of roasting whereas HMFA did not change. In the laboratory scale experiments, the highest concentration of 5-hydroxymethyl-furfural in coffee (909 microg/g) was obtained after 3 min and the maximum concentration of HMFA after 4 min (150 microg/g). Industrially roasted coffee contained up to 350 microg/g 5-hydroxymethyl-furfural and 140 microg/g HMFA.

Summary Background & aims Data on vitamin E content of foods are essential for nutrition research and its application. The aim of this study was to investigate the precision of calculated vitamin E content of prepared meals. Methods The vitamin E content of 69 dishes of a menu cycle sampled at two occasions were calculated using 4 different food composition tables (FCT) and measured by HPLC. Results Data were complete for 50–69 dishes. The proportion of dishes with differences between FCTs ⩽20% were 17–100%. Differences between HPLC and the Souci–Fachmann–Kraut table were ⩽20% in 8/46 dishes for α - and in 14/46 dishes for γ -tocopherol. Differences fell in the order of baked > raw> fried/roasted> boiled > mixed prepared foods. The 2 samplings taken 6 months apart showed considerable differences. Conclusions There are substantial differences in calculated/measured vitamin E content of prepared foods: (i) between different FCTs; (ii) between FCTs and HPLC, and (iii) between different seasons. This can be explained by intrinsic variability (breeding, season, country of origin, ripeness, freshness) and food processing, as well as selection of FCTs and should be taken into account when interpreting data of dietary intervention studies.