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A kinetic study of the phenolic compounds extraction from the solid residue remaining after the hydro-distillation of oregano (Origanum vulgare ssp. hirtum) was performed. Ethanol-in-water mixtures were used for the extraction and the effect of ethanol concentration, solid particle size, solid-to-liquid ratio, and temperature was examined. The experimental data were adequately fitted by both Peleg’s model and Fick’s law considering two stages of extraction, a high-rate initial one (up to 30 min), followed by a slower stage. The higher rate of phenolic compounds extraction was obtained with 60%, v/v ethanol. Increase in temperature from 22 °C to 60 °C, decrease in particle size (from >1000 μm to The HPLC analysis indicated mainly the presence of rosmarinic acid, lithospermic acid, flavonoid glycosides and carvacrol. The 60% ethanol as solvent exhibited the highest phenolics recovery and the strongest antiradical capacity. Increase in temperature from 22 °C to 60 °C led to improvement of both time and efficiency of the extraction performed with pure ethanol.

Rosemary residue, remaining after the distillation of essential oil, is currently unexploited, while it is a source of phenolic antioxidant components. This raw material was used for the extraction of phenolic compounds by aqueous ethanol or acetone in a continuously stirred reactor. The experimental results were fitted with a two-stage diffusion model. The highest extraction rates, total phenolic content (TPC) recovery, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity were obtained by acetone 60% and ethanol 60%. Grinding of the raw material enhanced the extraction rate and increased TPC yield and antioxidant capacity as the particle size decreased. Pre-treatment by maceration in water (4 h) dissolved a high amount of TPC and shortened the extraction time, while the combination with the pulsed electric field process did not provide further improvement. The use of ultrasound increased the efficiency of the extraction.

The distillation kinetics of the different essential oil components from four Lamiaceae herbs was investigated. Origanum vulgare L. ssp. hirtum, Origanum onites L., Origanum dictamnus L., and Satureja thymbra L. (harvests of 2013–2015), that present similar composition of essential oil were distilled in a laboratory-scale steam distiller. The recovery of the essential oil (EO) and its components was adequately described by non-steady state diffusion kinetics. The results clearly evidenced that the components present different distillation rates, thus resulting in variation of the EO composition during the process. The distillation rate constants decreased with the increase of the individual components boiling points, therefore, the heavy volatiles, such as carvacrol, could be recovered separately after the distillation of the most volatile compounds. This hypothesis was experimentally confirmed for O. vulgare and S. thymbra; the separate fractions were obtained from 40 and 50 min respectively up to the end of distillations. GC–MS analyses of the fractions revealed very high carvacrol content that amounted up to 92.5% for O. vulgare. The procedure could be applicable in industrial practice in order to recover fractions with pre-designed quality characteristics.

Aqueous solution of potassium hydroxide (KOH) was used in order to obtain rich in antioxidant activity extracts from Origanum dictamnus, Origanum hirtum, Origanum onites, Rosmarinus officinalis and Satureja thymbra, after removal of the essential oil via hydrodistillation. The increase of extraction time induced lower values of total phenolic content and DPPH radical scavenging ability of the extracts, while lower alkaline concentrations, i.e. 1% and 3%, proved to be more effective than 5% (v/w) KOH. The antioxidant activity of the extracts in sunflower oil was also measured by the oxidative stability index (OSI) method. OSI values decreased as extraction time increased, while the effect of KOH concentration at short extraction time was not significant. S. thymbra, O. hirtum and R. officinalis extracts showed high total phenolic content and good antiradical and antioxidant activity in just 30 min of extraction with KOH 1% (w/v). LC–MS analysis showed that all extracts were rich in phenolic acids, such as caffeic acid and rosmarinic acid, while R. officinalis was also rich in carnosic acid.

Background Lipid oxidation is one of the main causes of food spoilage. It can be delayed by the addition of antioxidants to food or by using vacuum or modified atmosphere packaging. A recent approach is the application of antioxidants in active packaging. Scope and approach The scope of this review is to present and update all information about the incorporation of natural antioxidants in edible and active films and coatings. Natural antioxidants can replace chemical additives and are preferably accepted by the consumers. Their effect on the barrier, mechanical and antioxidant properties of the various films (chitosan, cellulose derivatives gelatin etc.) are discussed. The ability to delay food oxidation is examined in relation to the active components. Key findings and conclusions Water or ethanol extracts from several herbs (rosemary, oregano, tea), berries, or plant by-products increased the total phenolic content and the antiradical activity of the films and proved efficient in delaying the oxidation of fish and meat products. Also, a protective activity was observed from the essential oils that were rich in carvacrol or thymol. The barrier properties of the films were positively affected, due to interactions between the active groups of the additive (e.g. polyphenols) and the film matrix. On the contrary, hydrophilic additives increased water vapor and oxygen permeability. The mechanical properties were in most cases adversely affected. Results are promising and further research on the release of antioxidant compound into food, the effect on sensorial properties, and application to other lipid foods may encourage practical application.

The antioxidant and antimicrobial properties of rosemary essential oil (EO) and extracts, entrapped in carboxyl methyl cellulose (CMC) edible coating for smoked eel were investigated. Analysis of the EO indicated 1,8-cineole, L-camphor, a-pinene, and 1-borneol, as the main components. The solid residue generated by the EO distillation was extracted in an ultrasound bath with ethanol to give an extract rich in rosmarinic acid, diterpenes and flavonoids. The addition of the extract at 200–800 ppm (total phenol basis) in CMC coating provided antioxidant protection to smoked eel, which increased with concentration. Additionally, the combination of the extract (200 ppm) with EO (2000 ppm) retarded significantly the formation of both primary and secondary oxidation products, indicating possible synergistic effects. The antimicrobial activity of EO and extracts was moderate, with the extract at 800 ppm concentration showing the best results in decreasing the rate of total viable count, Pseudomonas spp., and lactic acid bacteria growth.

Dried leaves of Satureja Thymbra were subjected to water-steam distillation to recover the essential oil (EO) and the water extract (Aq). The solid by-product was subjected to sequential Soxhlet extraction with ethyl acetate (EAc) and ethanol (EtOH). The obtained extracts were analysed by HPLC-DAD-ESI–MS/MS and the main flavonoids and phenolic acids were identified and quantified. The high antiradical activity of the extracts, as estimated by the DPPH assay, was correlated to their total phenol content. Moreover, the antioxidant activity of the extracts was tested in bulk palm oil and palm oil-in-water emulsions. EAc extract prolonged the induction period and reduced by 42% the rate of peroxide formation in palm oil, while EtOH extract was the most effective in emulsions. Additionally, the EtOH and EAc extracts depressed the growth of Listeria monocytogenes in emulsions deliberately spiked with 100 cfu/mL. The antimicrobial properties of EO, Aq, EAc, and EtOH extracts were assayed and the minimum inhibitory and non-inhibitory concentration values were determined. EO was effective against Staphylococcus aureus , Staphylococcus epidermidis , Escherichia coli , Listeria monocytogenes , Salmonella Enteritidis, Salmonella Typhimurium, Pseudomonas fragi, Saccharomyces cerevisiae and Aspergillus niger . In contrast, EAc and EtOH extracts were active only against the bacteria species, but not against S. cerevisiae and A. niger , while no antimicrobial activity was observed for Aq extract.

Sunflower oil-in-water emulsions were enriched with two Satureja thymbra extracts - obtained by ethyl acetate (EAcs) or ethanol (Es), rosmarinic acid (RA), or quercetin (Que), and the effect of storage temperature (5–40 °C) on the emulsions’ phenolic content and oxidative stability was studied. HPLC analysis of the extracts indicated RA as the main component. The phenolic content of the emulsions decreased during storage, following first-order kinetics, with a temperature-dependent rate. RA was the main compound that decreased, Que followed a slower decrease and the rest flavonoids remained almost constant. The additives protected the emulsion against oxidation according to the order Es > Que > EAcs > RA. The protection factor ranged from 73 to 81% at 5 °C, but decreased to around 53% for Que and Es, 33% for EAcs, and 22% for RA at 40 °C. Emulsions enriched with extracts from S. thymbra retain their phenolic content and oxidative stability at refrigeration temperatures.

The encapsulation of oregano essential oil in yeast cells was studied. Untreated cells, cells autolyzed for 8 and 24 h at 52 °C, cells treated with Pulsed Electric Fields at three different energy inputs (3.2, 13.6 and 107 kJ/kg) and cells treated with High Pressure Homogenization at 800 bar/4 passes were comparatively assessed. Encapsulation was performed by incubating the cell materials in contact with the oil at temperatures 30, 37, 45 and 65 °C for up to 48 h. Apart from homogenization, none of the other cell pretreatments affected the final encapsulation load at the temperatures studied. All pretreatments had a significant effect on the encapsulation kinetics, leading to increased encapsulation rates compared to the untreated sample. The essential oil release from the obtained capsules was found to depend on water activity and became significant above aw = 0.7, with cell pretreatments increasing the released oil percentage at higher water activities.

The effectiveness of Satureja thymbra (L.) extracts as potential antimicrobial or antioxidant agents in fish coating was studied. Dried leaves of the plant were subjected to steam distillation to recover the essential oil (EO). The solid residue was extracted successively with ethyl acetate and ethanol to recover the phenolic compounds. γ-Terpinene and carvacrol were the main components of EO, according to GC–MS analysis. LC–DAD–MS analysis of the extracts showed the presence of four main flavonoids and their derivatives in ethyl acetate, while rosmarinic and salvianolic acid A predominated in ethanol extract. The EO, ethyl acetate extract (EAcs), ethanol extract (Es), and their combinations were used in edible films to prolong the shelf life of fresh gilthead seabream (Sparus aurata) fillets. CMC solutions enriched with the extracts were prepared, the sliced fish fillets were soaked for 5 min in the solutions, packed aerobically, and stored at 0 °C. Microbial growth and oxidative deterioration was estimated. EO used alone showed a moderate antimicrobial and antioxidant protection. The EAcs and EAcs-EO combination showed the best antimicrobial effect, resulting in 25 and 35% shelf life extension, while the Es and Es-EO combination the best antioxidant activity, reducing the peroxide values by approximately threefold and eliminating the formation of secondary oxidation products.

Copigmentation of anthocyanins accounts for over 30% of fresh red wine color, while during storage, the color of polymeric pigments formed between anthocyanins and proanthocyanidins predominates. Rosmarinic acid and natural extracts rich in hydroxycinnamic acids, obtained from aromatic plants (Origanum vulgare and Satureja thymbra), were examined as cofactors to fresh Merlot wine and the effect on anthocyanin copigmentation and wine color was studied during storage for 6months. An increase of the copigmented anthocyanins that enhanced color intensity by 15-50% was observed, confirming the ability of complex hydroxycinnamates to form copigments. The samples with added cofactors retained higher percentages of copigmented anthocyanins and higher color intensity, compared to the control wine, up to 3 months. However, the change in the equilibrium between monomeric and copigmented anthocyanins that was induced by added cofactors, did not affect the rate of polymerization reactions during storage.

Industrial tomato processing by-products are intended mainly for animal feed or fertilizer, though they can be used for the recovery of valuable constituents. Carotenoids constitute an important component of these by-products, well credited with important health-promoting functions. This study examined the effect of several organic solvents (hexane, ethanol, acetone, ethyl acetate, ethyl lactate and their mixtures), and extraction temperature on the recovery and isomerization of carotenoids from tomato processing by-products. Another area under investigation was the stability of carotenoids, as affected by drying and storage conditions of tomato by-products. HPLC–DAD analysis was applied for the efficient separation and analysis of the carotenoids and their cis-isomers. The highest extraction yield was obtained with ethyl lactate (203.6 μg/g dry by-product) followed by hexane–ethyl acetate mixture with a considerably lower yield (36.1 μg/g dry by-product). The identified carotenoids in all solvent extracts followed the order: lycopene ≫ β-carotene > lutein, in their predominant trans-configuration. Among the identified isomers, 5-cis lycopene and 15-cis-β-carotene were the most abundant in all extracts. The increase of extraction temperature increased the total lycopene concentration in all extracts, whereas cis-isomers remained lower than 8 % in most solvents. A steadily high percentage of cis-isomer (≈30 %) was observed in ethyl lactate extracts, independent of temperature. Conversely, the increase of extraction temperature induced a reduction in total β-carotene and total lutein concentration in all solvents, while cis-isomers were not detected. Drying or even cold storage of the raw material led to decreased yields, and affected lycopene isomerization with a considerable increase of cis-isomers.

Aromatic and medicinal plants, like rosemary, oregano, sage, and winter savory, are rich sources of polyphenols. During the last decades, several researchers have tried to recover these highly valuable compounds by conventional or novel methods, mainly by microwave-assisted or ultrasound-assisted extraction. An overview of the obtained results is presented in this chapter. The type of solvent plays a major role in the quantitative extraction, and 60%–80% ethanol in water seems the most promising solvent for most of the phenolic groups. Recently, mild alkaline solutions have also been suggested to hydrolyze and recover bound phenolic compounds. The extraction time and temperature have a major effect on the yield, especially in microwave- or ultrasound-assisted extraction. Solvent-to-solid ratio of 20:1 to 40:1 proved efficient in most trials, whereas de-oiling and grinding the raw material, or even pretreatment with pulsed electric fields, improved the yield or shortened the extraction process.

The phenolic compounds are a vast class of secondary metabolites performing several roles for the defense and survival of plants. Their structure varies extensively, and thus they have been classified into groups according to the pattern of their basic skeletons. However, the resulting classes are also numerous and, furthermore, certain recently discovered compounds do not match the structural criteria to be included in the existing classes. For these reasons, Harbone attempted to modify the classification system. The phenolic compounds were divided into six classes; each class was further divided into categories and families of compounds to fully hierarchize their structural differences. The first five classes are characterized by an increasing complexity of the basic skeletons of the members, and the sixth class includes the so-called hybrid phenolics as a separate group of compounds.

Satureja thymbra extracts, rich in phenolic acids and flavonoids, were obtained through successive extractions with ethyl acetate and ethanol, and tested as natural antioxidants to prolong the shelf life of fried potato chips. The extracts were more effective when coated on a laminated film used as active packaging for the chips, compared to spraying them on the surface of the fried product or adding to the frying oil. The increased incorporation of the ethanol extract, as coating, from 100 to 300 mg total phenols (expressed as gallic acid equivalents, GAE)/m2 resulted in increased protection, as evidenced through peroxide values, volatile products, and oxygen consumption inside the packaging that remained stable for 55 days. Ethyl acetate extract was very effective up to a concentration of 200 mg GAE/m2, but demonstrated prooxidant activity at higher concentration. Partial migration of the natural polyphenols to the product was observed.

Enzyme (EA) and high pressure (HP) assisted extraction of carotenoids, especially lycopene, from tomato waste using various organic solvents was examined. Total carotenoid and lycopene extraction yields were increased by the use of pectinase and cellulase enzymes, when compared to the non enzyme treated solvent extraction process. The increase of extraction yield depended on the solvent. Maximum total carotenoid (127 mg/kg d.w.) and lycopene (89.4 mg/kg d.w.) extraction yields were obtained in enzyme treated samples extracted with ethyl lactate (solvent:solid = 10:1 mL:g), corresponding to almost 6-fold and 10-fold increase, respectively, with respect to non enzyme treated samples. HP assisted extraction led to higher extraction yields (from 2 to 64% increase depending on the solvent used) compared to conventional solvent extraction process performed at ambient pressure for 30 min. HP assisted solvent extraction was successfully performed at 700 MPa by using significantly ( P

Industrial tomato processing generates large amount of low-value by-products, primarily used as livestock feed or disposed of; however, being a rich source of natural carotenoids, tomato waste can be used to produce high value-added products for food, cosmetics, or pharmaceutical applications. The objective of this review is to summarize and give an overview of the extraction methods available for the recovery of carotenoids and, especially, lycopene from tomato processing by-products. Organic solvent extraction techniques are presented and the effect of extraction conditions on carotenoids recovery is evaluated. In particular, the use of Ultrasound Assisted (UAE), Microwave Assisted (MAE), Enzyme-Assisted (EAE) and Extraction at High Pressure (HPE) for the recovery of carotenoids is assessed. Also, this review examines the efficiency of Supercritical Fluid Extraction (SFE) and in particular the effect of process parameters on carotenoid recovery from industrial tomato waste.

Mavrokountoura, a clone of the Mandilaria grape cultivar, was studied for the first time. The morphological characteristics and composition of berries were determined, as well as total phenols and tannins in skins, flesh, and seeds. The skin anthocyanins were identified using HPLC-MS/MS and quantified using HPLC-DAD. Two main anthocyanins were identified as malvidin-3-O-glucoside and malvidin-3-O-(6″-p-coumaroyl)-glucoside. One minor anthocyanin was identified as malvidin-3-O-(6″-acetyl)-glucoside. Glycosides of delphinidin, petunidin, and peonidin were detected in traces. Young Mavrokountoura wine was also studied. Extraction of total phenols from the grape to the young wine amounted to 32%, composing mainly non-tannic phenols. The individual anthocyanin components exhibited different extractability values from the skin to wine, ranging between 10–94%.

Fat was replaced at 35% to 100% in cakes by maltodextrin (dextrose equivalent = 3), inulin (high performance and granulated), oligofructose, citrus pectin, and microparticulated protein. Fat replacement by 35% did not induce significant differences in general. Above 65% fat replacement resulted in statistically significant (P < 0.05) decreased viscosity (except for pectin) that was followed by statistically significant decrease in air incorporation and broader bubble size distribution. The starch gelatinization temperature showed a statistically significant increase when fat was replaced by fructose oligosaccharides. The cakes presented statistically significant increase of hardness, elasticity, and decrease of volume development as fat replacement increased above 65%. Also cakes with increased fat replacement received lower scores on taste and flavor, whereas at total fat replacement they were evaluated as not acceptable. Nevertheless, at 65% fat replacement, the samples presented acceptable textural, physical, and sensorial attributes.

Because many common foods are emulsions (mayonnaise, coffee creamers, salad dressing, etc.), a better understanding of lipid oxidation mechanisms in these systems is crucial for the formulation, production, and storage of the relevant consumer products. A research body has focused on the microstructural and oxidative stability of protein-stabilized oil-in-water emulsions that are structurally similar to innovative products that have been recently developed by the food industry (e.g., non-dairy creams, vegetable fat spreads, etc.) This review presents recent findings about the factors that determine the development of lipid oxidation in emulsions where proteins constitute the stabilizing interface. Emphasis is given to “endogenous” factors, such as those of compositional (e.g., protein/lipid phases, pH, presence of transition metals) or processing (e.g., temperature, droplet size) nature. Improved knowledge of the conditions that favor the oxidative protection of protein in emulsions can lead to their optimized use as food ingredients and thereby improve the organoleptic and nutritional value of the related products.

The antioxidant activity of carotenoids (β-carotene, lycopene, paprika, marigold, bixin- and norbixin-rich annatto extracts) was estimated in sunflower oil-in-water emulsions (o/w) stabilized either by Tween 20 or by a mixture of Tween 20 and sodium caseinate at equal concentrations. Both polar (paprika, marigold, bixin, norbixin) and hydrophobic (β-carotene, lycopene) carotenoids exerted a clear antioxidant effect during thermal accelerated autoxidation (60 °C) of o/w emulsions stabilized by Tween 20, while in the protein-based emulsions only polar carotenoids acted as antioxidants against the production of primary and secondary oxidation products. Furthermore, o/w emulsions, containing different concentration of paprika and bixin-rich annatto extract (0.25–1.5 g/L) in the lipid phase oxidized slower than the control emulsions. Meanwhile, the rate of carotenoids' degradation revealed that polar carotenoids, which presented antioxidant effect in both protein and Tween 20 stabilized emulsions, presented a higher rate of degradation than the hydrophobic carotenoids.

BACKGROUND: The aim of this research was to investigate whether certain polyols (mannitol, maltitol, sorbitol, lactitol), fructose, oligofructose and polydextrose can replace sugar (by an equal amount of each substitute) in cake formulations. The rheological behaviour of the cake batter and the physical characteristics of the cakes containing sugar substitutes were compared with the respective attributes of the control cake. Differential scanning calorimetry was used to investigate the effect of sugar substitutes on starch gelatinisation. Furthermore sensorial characteristics were evaluated by instrumental measurements and sensory evaluation. The correlation of the batter characteristics with the textural attributes of the final product was also attempted. RESULTS: The best results were obtained by using oligofructose, lactitol or maltitol as sugar replacers, which exhibited similar behaviour to sucrose in terms of batter rheology and increased starch gelatinisation temperature. Fructose and mannitol led to cakes of poor quality characteristics, as was demonstrated by instrumental measurements and sensory evaluation. CONCLUSIONS: Batter rheological behaviour as well as the ability of sugar substitutes to increase starch gelatinisation temperature proved to be controlling factors of the textural properties and volume of the cakes. The sensory evaluation indicated that overall acceptance followed closely the scores of tenderness and taste. Copyright © 2011 Society of Chemical Industry

Bulk oils and oil-in-water emulsions were subjected to high hydrostatic pressure (HHP) (200, 650 MPa) treatment so as to estimate the effect of applied pressures on lipid oxidation. HHP-treated and non-treated samples were left to autoxidise under accelerated conditions (2 weeks, 70 °C) and their oxidative status was periodically estimated by measurement of conjugated dienes and peroxide value. Total changes of thiobarbituric acid-reactive substances were recorded as additional oxidative markers for emulsions. Results showed an increase in oxidation as pressure was increased especially at 650 MPa. Lipid oxidation rates that were more pronounced for HHP-treated samples can be correlated to measured dissolved oxygen that was also higher. HHP did not seem to have an effect on emulsion droplet size. The addition of Majorana syriaca (200 ppm) ethyl acetate extract led to protection against lipid oxidation under HHP and atmospheric conditions, 20.9–38.7% and 28.9–43.2%, respectively. It was observed that the antioxidant effect of M. syriaca extract under HHP was weaker.

Summary This study evaluates the antioxidant effectiveness of a natural extract obtained from Majorana syriaca in fried and baked foods. Majorana syriaca was extracted with ethyl acetate (yield 129 g kg−1, dry basis) and the extract was added to refined corn oil at a concentration of 500 ppm. The oil was used in deep frying of potato chips at 185 °C and in making baked cookies. Potato chips and cookies were further subjected to accelerated oxidation at 70 °C. The protection of the frying oil was moderate as indicated by the polar content and conjugated dienes (CD) measurements, however, a remarkable improvement of the oxidative stability of the fried chips was observed through the decrease of peroxide value (PV) and CD by 59–72% and 51–79%, respectively, compared to samples with no additive. Also, the PV and CD of cookies decreased by 79% and 72%, respectively.

Tomato waste is an important source of natural carotenoids. This study was carried out to assess the extractability of tomato waste carotenoids in different organic solvents and to optimise the extraction parameters (type of solvent, extraction time, temperature and extraction steps) for maximum yield. Among other solvents, we tested a new environmentally friendly one, ethyl lactate, which gave the highest carotenoid yield (243.00 mg kg -1 dry tomato waste) at 70 °C, compared to acetone (51.90 mg kg -1 ), ethyl acetate (46.21 mg kg -1 ), hexane (34.45 mg kg -1 ) and ethanol (17.57 mg kg -1 ). The carotenoid recovery was significantly (P < 0.05) affected by the number of extraction steps and temperature in all solvents. Mathematic equations predicted rather satisfactorily (R 2 = 0.89-0.93) the rate of carotenoid extraction in the above-mentioned solvents. Carotenoid concentration increased with time, approaching a quasi-saturated condition at approximately 30 min of extraction.

Introduction Rapid test methods are increasingly being promoted as tools for food companies to validate and/or verify the efficacy of their food-safety management systems. However, little is known about their take-up by the industry nor on what industry's current and future needs are. Objectives In order to gain further information a questionnaire-based survey was conducted in 17 countries (11 European Union members and 6 non-European Union members). The survey was designed to gain insight into routine analytical regimes operated by food industries and the role played in them by the use of rapid test methods. Methods Over 2600 questionnaires were circulated to companies covering the whole food chain and 661 replies (about 25%) were received. Results At a strategic level, the survey revealed that raw materials and final products are the most routinely analyzed samples, and that the major analytes tested for concerned (in descending order) microbiological contaminants, heavy metals, pesticides, foreign bodies, mycotoxins and allergens. With regard to the use of rapid test methods, 66% of the respondents use them, while, almost all respondents stated their interest for extending the range of tests performed. In terms of future needs, rapid tests for microbiological analysis was emphasized by most respondents, while food allergens and mycotoxins-related test kits were also of high importance. Conclusions The results obtained indicate that the food industries currently use or are well prepared for the implementation of new rapid methods of analysis. Lebesi D, Dimakou C, Alldrick AJ, Oreopoulou V (2010). Rapid test methods: a versatile tool to assist food-safety management. Quality Assurance and Safety of Crops & Foods, 2, 173–181.

Extra virgin olive oil was produced from olives of the two main varieties cultivated in the region of Rethymnon in the Greek island of Crete named “Throumbolia”, and “Koroneiki”. The former is very famous due to the natural way of fruit debittering, while the latter is the most common olive variety cultivated in Northern Greece. The olives were harvested at three successive stages of ripening according to their skin color and the extra virgin olive oil was extracted using an experimental olive oil extraction mill at 30ºC. Peroxide value, UV absorption, acidity, fatty acid content and total polyphenols were measured and the contents of tyrosol, hydroxytyrosol 3,4- DHPEA-EDA, p-HPEA-EDA and 3,4-DHPEA-EA were determined by HPLC. The sterol fraction and the volatile component profile were determined by GC and SPME GC/MS, respectively. Throumbolia olive oil presented an extremely higher content of β-sitosterol and linoleic acid (n6) in comparison to the Koroneiki variety. The concentration of linoleic acid decreased in olive oils produced from both varieties in contrast to oleic acid which increased at the same time. Furthermore, the content of OH-tyrosol was higher, while the content of 3, 4-DHPEA-EDA and the total polyphenols was lower in Throumbolia olive oil than in olive oil produced from the Koroneiki variety. In general, significant differences were observed in all parameters between the olive oils produced from the two varieties during different stages of maturation.Aceite de oliva virgen extra fue producida con aceitunas de las dos principales variedades cultivadas en la región de Rethymnon en la isla de Creta denominadas “Throumbolia” y “Koroneiki”. La primera es una variedad muy famosa debido a la falta de amargor natural de su fruto, mientras que la última es la variedad más común de aceitunas cultivada en el norte de Grecia. La aceitunas fueron cosechadas en tres estados sucesivos de maduración de acuerdo al color de su piel y el aceite de oliva virgen extra fue extraído en una almazara experimental a 30ºC. El indice de peróxides, la absorción UV, la acidez, el contenido en ácidos grasos y los polifenoles totales fueron medidos y los contenidos de tyrosol, hydroxytyrosol 3,4- DHPEA-EDA, p-HPEA-EDA y 3,4-DHPEA-EA fueron determinados por HPLC. La fracción de esteroles y el perfil de los componentes volátiles fueron analizados por GC y SPME GC/MS, respectivamente. El aceite de olovas de Throumbolia presentó un contenido extremadamente más alto de β-sitosterol y ácido linoleico (n6) que la variedad koroneiki. La concentración del ácido linoleico decrecio en ambas variedades, a diferencia del ácido oleico que presentó un incremento al mismo tiempo. Además, el contenidode OH-tyrosol fue más alto, mientras que el contenido de 3,4-DHPEA-EDA y los fenoles totales fueron más bajo, en aceite de oliva de Throumbolia que en el aceite de oliva producido por la variedad Koroneiki. En general, diferencias significativas fueron observadas en todos los parámetros entre los aceites de oliva producidos por las dos variedades durante las diferentes etapas de maduración.

The activity of natural carotenoid extracts against the autoxidative deterioration of sunflower oil-in-water emulsions was estimated in terms of primary (lipid hydroperoxides) and secondary (“off flavour” volatiles) oxidation products. At a concentration of 2 g l −1 , the tested carotenoids did not inhibit the production of hydroperoxides but they significantly retarded the formation of volatile aldehydes during the storage of simple tween-stabilised emulsions at 30 °C. In another series of experiments, several carotenoid extracts (paprika, annatto and marigold preparations) containing mainly polar carotenoids, added at an active concentration of 1 g l −1 , exerted a strong activity against hydroperoxides and TBARs during the accelerated oxidation (60 °C) of homogenised protein-based emulsions. On the contrary, carotene preparations rich in hydrophobic α- and β-carotenes and lycopene did not significantly differ from the control emulsion. Therefore, the carotenoid structure modulated their antioxidant effect, while concentration and emulsion structure may also affect carotenoid activity in protein dispersed systems.

MoniQA (Monitoring and Quality Assurance in the total food supply chain) is a Network of Excellence funded under the EU 6th Framework Programme. Its aim is to work towards the harmonization of worldwide food quality and safety monitoring and control strategies by establishing durable integration of leading research institutions, industrial partners and small and medium enterprises working in complementary fields of food quality and safety analysis. One of the main objectives of the project is to ‘develop harmonization guidelines for validation and standardization of detection methods and technologies in food safety and quality’. To achieve this, the relative importance of the range of contaminants and residues causing problems in food needed to be established. This paper outlines the methodologies adopted for prioritizing harmonization issues and identifying needs for research and development of analytical methods within the areas of natural contaminants (bio-toxins, food allergens), microbiological contaminants, chemical contaminants originating from environmental sources (heavy metals, etc.), industrial activity (dioxins, polychlorinated biphenyls, etc.) or agricultural practices (pesticides and veterinary drag residues), food additives (colourants, sweeteners, etc.), processing contaminants (acrylamide, trans fatty acids, etc.) and authenticity (cheaper substitutes, fraud, etc.). Qualitative methods are also included in the prioritized activities, as there are no internationally accepted validation protocols.

Summary The antimicrobial and antioxidant effect of Majorana syriaca extract, obtained by ethyl acetate, to Yellowfin tuna was examined. The extract was added to refined corn oil at different concentrations (0–3900 ppm). Minced tuna was mixed with corn oil containing the extract (tuna/oil: 3/1 w/w); the mixture was packed aerobically and stored at 0 °C. Microbial growth and lipid oxidation were determined periodically. Majorana syriaca extract delayed the microbial growth (total viable count, Pseudomonas sp. and lactic acid bacteria) as compared with pure minced tuna, with an increasing effect as concentration increased. Oxidation was monitored through measurement of peroxide value and thiobarbituric acid-reactive substances. Both tests showed inhibition of tuna oxidation as the concentration of the extract increased. The results of the study show the potential of M. syriaca extract in extending the shelf life of tuna fish.

Three alternative extraction procedures were carried out in order to separate the antioxidant components and isolate an efficient extract from Origanum dictamnus . Procedure A included sequential extractions with petroleum ether (PE), diethyl ether (DE) and ethanol; procedure B sequential extractions with PE and ethyl acetate (EAc); procedure C a single step extraction with ethanol. The most efficient radical scavengers, according to the DPPH method, were isolated in ethanol extract of procedure A (mainly rosmarinic acid), followed by ethanol extract of procedure C. However, both ethanol extracts had low solubility in oil and could not protect it. EAc and DE extracts, containing mainly apigenin and epirosmanol ethyl ether, presented lower radical scavenging activity but were very effective against autoxidation of cottonseed oil (a concentration of 200 ppm was adequate to stabilize it). PE extract protected the oil effectively at concentration of 350 ppm, while being the least active against DPPH. Industrial relevance This study examines Origanum dictamnus as a potential antioxidant additive for edible oils and fats. Three different extraction procedures of the raw material with non-toxic organic solvents were used to recover the sum of the extractable compounds and specific fractions respectively. The extraction procedures, accompanied with analytical techniques, led to the characterization of the antioxidant properties and the composition of the plant as well as the isolation of very efficient oil-soluble antioxidant fractions.

HPLC-DAD coupled with mass spectrometry in the positive ionization mode was applied to study the fragmentation of twelve selected flavonoids. Compounds belonging to all the major subgroups found in common plants, i.e. flavonols, flavones, dihydroflavonols, flavanones and flavanols were studied. Compound standards were injected into the spectrometer and produced characteristic mass spectra. The fragmentation of each compound was studied and it was shown that the dehydration and carbon monoxide losses from the [M+H]+ ion by the members of each subgroup produced specific fragments, thus allowing the characterization of the flavonoid subgroups. Moreover, fragments resulting from fission of the C-rings are specific of each subgroup and revealed the substitution pattern of A- and B-rings. In order to verify the identifying efficiency of the positive ionization mode through these characteristic fragmentations, the unknown flavonoids of an Origanum vulgare diethyl ether extract were separated with the HPLC system and the major peaks were successfully identified with the mass spectrometer.

Structure—activity relationships of flavonoids against cottonseed oil oxidation are the objective of this work, which focuses on the contribution of C-ring and 5,7-di-OH A-ring. Flavonoids with a catecholic B-ring, namely quercetin, fisetin, luteolin, taxifolin, (+)-catechin and eriodictyol were added in increasing concentrations to cottonseed oil and the induced decrease in the rate constant of peroxide formation (k) and peroxide values (PV) were determined. The flavonoid depletion was monitored during the autoxidation with high-performance liquid chromatography-diode array detector (HPLC-DAD) analysis. The fully substituted C-ring was established as the most significant element for maximal antioxidant activity; quercetin even decreased k by 86% in comparison with the control and presented the highest decrease of PV per mmole of antioxidant. Flavonoids missing the 2,3-double bond or the 3-OH (taxifolin, luteolin) resulted in a smaller decrease of k, and the lack of both of the above structural elements (eriodictyol) resulted in the smallest decrease. Lack of the 4-carbonyl in the C-ring had the least negative effect on antioxidant activity since (+)-catechin presented the strongest protection after quercetin and fisetin. The activity of the latter flavonoid proved that A-ring hydroxyls, despite the unfavorable m-configuration, participate in the stabilization of the lipid substrate, although their significance was secondary.

The present paper examines whether certain processing factors may influence the oxidative stability of whey protein oil-in-water emulsions, which are structurally close to innovative industrial products (e.g. “fresh-cheese” and “non-dairy cream” types). We first checked whether the thermally induced whey protein denaturation might correlate with oxidative changes, in whey protein emulsions prepared with heat pre-treatment at varying temperatures (40–85 °C). The results showed that an increase of whey protein denaturation (in particular at >60 °C temperatures) was associated with a decrease of emulsion oxidative sensitivity, in terms of conjugated diene hydroperoxides production. In model whey protein emulsions prepared at 70 °C under varying homogenisation pressures (30–600 bars), any effect of the droplet size on the oxidative changes was subsequently investigated. The measurements of conjugated dienes or TBARs did not reveal a clear trend of changes for either of these oxidative indicators with emulsion droplet size.

This work attempts to determine any relationship between certain endogenous parameters and the oxidative deterioration of protein-stabilized oil-in-water emulsions. The contribution of compositional factors (e.g., type and amount of emulsifier, fat phase, etc.) is further elucidated. Among 10% cottonseed o/w emulsions prepared by 1% emulsifier (Tween, sodium caseinate, or whey protein), lipid autoxidation (at 40°C) was much faster in the Tween emulsion than in the protein ones, with whey protein presenting a clear antioxidant effect. Increase in protein concentration (0.5–2% w/w) led to a decrease in droplet size but an increase in oxidative stability, in terms of conjugated diene hydroperoxides formation at 232 nm. The type of lipid phase significantly affected the rate of thermal oxidation at 60°C. In the most oxidatively vulnerable sunflower-oil-based emulsions, an increase in fat content (10–40%) resulted in a reduction of oxidative deterioration. By selecting a more concentrated emulsion (20% o/w, 2% emulsifier), in order to structurally approach real novel food products, any influence of the composition of the emulsifier (combination of Tween and sodium caseinate preparation) was subsequently tested. An increase in protein proportion in the emulsifier was found to inhibit proportionally the oxidative instability of the emulsions, as evaluated by the determination of both primary (conjugated diene and lipid hydroperoxides) and secondary [thiobarbituric acid-reactive substances (TBARS)] oxidation products.