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Conventional dark chocolate production methods that are applied in the industry consist of several steps, which require equipment with big investment costs. There are however few cost-effective alternatives suggested for small-scale production. Meanwhile, knowledge on these alternative equipment/techniques are insufficient to promote miniature production of high quality chocolates, either for research purposes in an industrial context, or for producers in developing countries, where the cost of investing in conventional equipment seems to be an impediment. The aim of this study was two-fold; first, to assess the feasibility of utilizing the ECGC-12SLTA CocoaTown melanger as an alternative to the conventional 3-roll refiner at different settings and fat content. Thereafter, one optimal setting was selected for each equipment for further investigation on the impact of the refining on some quality attributes of the final dark chocolate (70% cocoa). Secondly, the Stephan mixer; being used to mimick a conching-like process, was assessed with respect to two processing factors; the dry conching temperature (60 °C, 80 °C) and the duration of vacuum pump connection (0, 30, 60 min). The latter was to facilitate adequate moisture removal. The melanger proved to be a suitable alternative to the 3-roll refiner, provided that refining was carried out at moderate/high (ca. 40%) fat content, as is often the case for “high-percentage-cocoa” chocolates. Refining for 180 min with the mini drum at 40% resulted in D (v,0.9) significantly (p

The impact of pod storage (PS) and roasting temperature (RT) on the aroma profiles of dark chocolates were evaluated. Cocoa liquor samples comprised of ten different combinations of PS and RT, whilst keeping the roasting time fixed at 35 min. Additionally, commercial cocoa liquors from renowned origins (Ecuador, Madagascar, Venezuela, Vietnam, Ivory Coast and Ghana) were acquired for comparison. From these, 70% dark chocolates were produced under the same conditions after which they were subjected to headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPME-GC–MS) analysis. Although both PS and RT were found to influence the aroma volatile concentrations, the impact of RT over PS seemed to be greater. An agglomerative hierarchical clustering (AHC) of all chocolates on the basis of their aroma profiles revealed a similar impact as earlier observed, where major clustering of the chocolates was in accordance with the intensity of the roasting process applied. However, within each group, the dissimilarities owing to PS among the chocolates was clearly depicted. Comparatively, chocolates with low (100–120 °C), instead of moderate to high (135–160 °C) RT's, rather showed a low dissimilarity with those from the commercial cocoa liquors of the different origins. Although from the same beans, the diversity of aroma profiles of these chocolates as well as the similitude of some treatments to some chocolates from commercial grade cocoa liquors, unequivocally underscores the possibility for steering diverse distinct flavors from ‘bulk’ cocoa through PS and roasting, with beneficial implications, both from an application and an economic point of view.

The use of alternative equipment for chocolate production is gaining attention in recent times in many countries. This is due to the lower cost of investment and maintenance, multi-functionality, and lower throughput. This study was conducted to investigate the applicability of two of such equipment; melanger and Stephan mixer. In the first set-up, the possibility of refining chocolate with the melanger in comparison with the conventional 3-roll refiner was explored. Whereas in the second set-up, the applicability of the Stephan mixer (aided with a vacuum pump) for a conching-like application was also investigated. From each set-up, 70% dark chocolates produced through various alternative means were then evaluated on the basis of their flavor profiles. Specific groups of volatiles such as aldehydes, ketones, terpenes and terpenoids, showed significant (p 0.05) preference for these representative chocolates from the clusters. These findings stimulate various practical application possibilities for tuning chocolate flavor through alternative processing for both industries and various artisans worldwide.

Palm sap sugar is a natural alternative sweetener that can be made from the sap/nectar of several species of palm tree flowers. In this work, a thorough investigation about the impact of chemical composition and physical properties of palm sugar on the formation of aroma and appearance of dark chocolate was carried out. Five sucrose–palm sugar blends with different palm sugar (PS) proportion, namely PS0, PS25, PS50, PS75, and PS100, were used as sweetener. The results showed that a higher concentration of some alkyl pyrazines, alkyl furans, alkyl alcohols, 2-acetylpyrrole, and acetic acid observed in the palm sugar-sweetened dark chocolate could be attributed to the aroma profile of palm sugar. In addition, there were some aroma volatiles which were only observed in palm sugar-sweetened dark chocolate, such as 2-furoic acid, 3-hydroxy-2-butanone, 1-hydroxy-2-propanone, 2,3-dihydro-5-dihydroxy-6-methyl-4H-pyran-4-one, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). The higher the proportion of palm sugar, the higher the concentration of these volatiles. Aside from this, the presence of more amorphous sugar was probably responsible for a higher concentration of aroma volatiles in chocolates containing palm sugar. Regarding the chocolate appearance, the effect of particle size in determining the colour was less pronounced than the effect of particle density and possible sugar network formation in the chocolate. The latter factor, might affect the surface roughness, resulting in different colour parameters. It seemed that the Maillard reaction during chocolate processing, which may influence the aroma profile and darkness of chocolate, occurred in much lesser extent that in the palm sugar production.

Cocoa products are obtained from the seeds of Theobroma cacao L. In this research, cocoa liquor and chocolate produced from cocoa beans from West Africa (Forastero, “bulk” cacao) and Ecuador (Nacional variety, “fine-flavor” cacao), were investigated, using a novel approach in which various analytical techniques are combined in order to obtain in-depth knowledge of the studied cocoa samples. The levels of various classes of primary metabolites were determined and a wide range of secondary metabolites, including volatile organic acids, aldehydes, esters, pyrazines, polyphenols, methylxanthines and biogenic amines, were identified and/or quantified by HS-SPME GC–MS (headspace-solid phase microextraction gas chromatography - mass spectrometry). and UPLC-HRMS (ultra-performance liquid chromatography - high resolution mass spectrometry). Odor Activity Values (OAV) were calculated to assess the contribution of individual volatiles on the final aroma. Various volatile aroma compounds were more abundant in the West African cocoa liquor and chocolate, while the Ecuadorian samples were richer in most quantified non-volatile metabolites. Principal component analysis (PCA) confirmed that the four samples can be clearly distinguished. Alcohols, pyrazines, amino acids and biogenic amines were found to be highly influential in causing this differentiation. The proposed approach can be useful in future studies on more extensive cocoa sample collections, in order to highlight similarities and pinpoint typical differences in chemical composition among these samples.

The impact of pod storage (PS) and roasting temperature (RT) on the quality parameters and the sensory profiles of dark chocolates were evaluated. Dark chocolates (70%) from ten liquors of different PS and RT combinations as well as six liquors of different origins (Ecuador, Ghana, Ivory Coast, Madagascar, Venezuela and Vietnam) with variable genetic groups were produced under identical conditions and compared. To a greater extent, the range of chocolate quality attributes underscored the generally minimal effects of PS, RT and origin of liquor on the processing conditions. Although with a few exceptions, generally, chocolate acidity (pH and TA) decreased with increasing PS and vice versa in the case of RT. Furthermore, results from a balanced incomplete block design (BIBD) involving a 16-member expert panel also revealed the impact of the applied treatments (PS and RT) on the final flavor profiles of the chocolates irrespective of the origin or genetic groups of the cocoa beans. The same was confirmed when instrumental aroma results were correlated with the sensory data using partial least squares (PLS) regression models. Thus, this study demonstrates the possibility of creating diverse flavor profiles (even towards ‘fine’ flavor) from ‘bulk’ cocoa beans through an optimized combination of PS and RT. The findings are therefore expected to challenge the status-quo, especially in the way ‘bulk’ cocoa is currently processed and consequently priced, thereby, possibly fostering a win-win situation between cocoa producers and industries.

Palm sugar is highly produced and patronised in the south-eastern part of Asia, e.g. Indonesia which is also the world’s third largest cocoa producer. Recently, interest in palm sugar sweetened chocolate and better approaches for production methods that can be easily applied in developing countries are rising. This work investigated the influence of palm sugar on the quality attributes of dark chocolate in terms of fineness, rheological behaviour and aroma profile compared to that of sucrose. Furthermore, a small-scale processing approach using the combination of Stephan mixer and ball mill compared to the conventional method was investigated. The results showed that palm sugar sweetened chocolate exhibited a higher viscosity, a higher particle volume fraction and a higher degree of particle agglomeration due to its relatively high moisture and presence of glucose and fructose. Furthermore, chocolates sweetened with palm sugar displayed a distinctive aroma profile with the abundant presence of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one and pyrazine-based compounds. Applying the alternative processing method leaded to the production of chocolate with rather high degree of agglomeration and viscosity as compared to chocolate produced by means of conventional processing. Moreover, the alternative processing method resulted in the presence of myrcene, β-trans-ocimene and isoamyl acetate which were not observed in the conventionally produced chocolates. The alternative processing method, however, seems to have potential for small-scale production of dark chocolate sweetened with palm sugar.

Previously, it has been observed that lipolysis occurring during (even short term) wet storage of microalgal biomass causes high free fatty acid (FFA) concentrations in the biomass. These FFA have a negative impact for different applications of microalgal lipids, e.g. downstream processing problems in biodiesel production, off-flavors and loss of nutritional value for food applications. However, it is not clear which factors influence lipolysis in microalgal biomass and which lipid class are more susceptible to lipolysis. In this study, wet biomass of T-Isochrysis lutea was stored at 20°C, 4°C and -20°C during 3 weeks. The extent of lipolysis was followed by analyzing the lipid classes distribution by ultrahigh-performance liquid chromatography−accurate mass mass spectrometry (UHPLC-amMS) and the FFA content. It was observed that FFA were formed very rapidly during post-harvest storage of wet biomass at 20°C and 4°C, the rate of this process being faster at 20°C than at 4°C, while almost no lipolysis was observed at -20°C. However, the FFA content levelled off after several days of storage because FFA reacted with alcohols to form fatty acyl esters. publisher: Elsevier articletitle: Lipolysis in T-Isochrysis lutea during wet storage at different temperatures journaltitle: Algal Research articlelink: http://dx.doi.org/10.1016/j.algal.2016.07.003 content_type: article copyright: © 2016 Elsevier B.V. All rights reserved. ispartof: Algal Research vol:18 pages:281-287 status: published

Consumer demand for healthier alternative sweeteners and attempts to replace the most common sweetener used in chocolate, namely sucrose, continue to increase in recent times. One sucrose alternative that has not been fully explored in chocolate is palm sap-based sugar. This work investigated the impact of sucrose replacement by coconut sugar (CCS1 and CCS2) and palm sugar (CPS1, CPS2 and CPS3) on the quality attributes of dark chocolate, more particularly colour, hardness, flow behaviour and aroma profile. The results showed that chocolates formulated with palm sap-based sugar were lighter in colour and harder than the reference chocolate made with sucrose, which could be attributed to a lower particle density and a higher moisture of palm sap-based sugar than that of sucrose. Analysis of the major volatile compounds recorded the presence of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) and high concentration of pyrazine-based compounds in the palm sap-based sugar-sweetened chocolates. The former compound (DDMP) was, however, absent in the sucrose-sweetened dark chocolate. The physicochemical properties of the sugars also had a significant effect on the rheological behaviour of the final chocolates with chocolates formulated with coconut sugar recording the highest Casson viscosity. With regard to fat melting, chocolates sweetened with palm sap-based sugar and sucrose exhibited similar melting range temperature. Palm sap-based sugar nevertheless seems to have great potential for dark chocolate applications with additional health benefits.

This study provides the quality aspects of Vietnamese (VN) dark chocolates produced by cocoa liquors exhibiting different degrees of acidity. Hereto, the impact of preconching the highly acidic cocoa liquors was investigated. Results show that three out of four VN chocolates attained comparable solid fat content at 35C, particle sizes and flow properties to a Ghanaian reference, ensuring a similar volatile release and taste perception. Principal component analysis of the aroma compounds obtained using headspace solid-phase microextraction gas chromatography mass-spectrometry clustered the chocolates into three groups: those from GH and VN liquor with intermediate acidity, those from preconched VN liquors and that from highly acidic VN liquor. A more detailed interpretation of the flavor profile revealed that VN chocolates exhibit more profound acidic, fruity and flowery aroma. Furthermore, liquor preconching positively affected chocolate flow and decreased volatile acids, however, partly removed both highly and less volatile, desired aroma compounds. Practical Applications As the demand and deficit for chocolate are increasing worldwide, the hunt for additional high-quality cocoa resources will bring added value for both farmers and chocolate industry. Vietnamese (VN) cocoa, as a newcomer, is recently expanding its global market potential, however, how its quality can be positioned in the world supply is not assessed yet. The results of this study could reveal the applicability of VN cocoa liquors varying in acidity for the production of high-quality dark chocolates with specific aroma notes. However, the typical high acidity in Southeast Asian cocoa is regarded as detrimental flavor attribute, thus inspiring this work to study whether cocoa liquor preconching could improve the overall aroma as well as mouthfeel perception.

Effects of non-thermal plasma (NTP) technology on the aroma and phenolic compositions and inactivation of lipoxygenase (LOX) enzyme activity of extra virgin olive oil were investigated for the first time. A short non-thermal plasma treatment with pure argon gas (2 standard liters per minute and an average voltage of 7 kV) was applied for 135 s on the olive oil sample. The LOX activity in the NTP treated oil was inhibited up to 42.9% in comparison with untreated oil. Mean values of the peroxides in both samples, expressed in meq oxygen/kg of oil, did not show any statistically significant difference. The values of the antioxidant potentials in the samples proved a mild reduction after NTP treatment. A total of 14 phenols and 31 volatiles were found in both samples with same profile. Although there was a slight difference in the test samples with regard to the concentration of individual phenolic and aroma compounds, this difference was not statistically significant. Therefore, NTP treatment had no statistically significant influence on the antioxidant activity, peroxide value, phenols and volatiles, except LOX activity. © 2019 Elsevier Ltd FDK-2015-5285 We thank the Çukurova University Research Found (No: FDK-2015-5285 ) for financial support. We also wish to thank Assoc. Prof. Dr. Muharrem Keskin from Hatay Mustafa Kemal University, Turkey and Prof. Dr. Abdul Malik from Aligarh Muslim University, India for their outstanding editing and proof reading.

Microalgae have already shown their potential as an alternative source of n-3 LC-PUFA. In this study, 5 different microalgal species (Isochrysis, Nannochloropsis, Phaeodactylum, Porphyridium and Schizochytrium) were added to an acidic model system and screened on their potential use in acidic food matrices. The impact of mechanical and thermal processing on the model systems was studied by analyzing the amount of n-3 LC-PUFA, free fatty acids, carotenoids, lipid polymers and the oxidative stability. A (limited) reduction of n-3 LC-PUFA was observed. Thermal alterations combined with the presence of free fatty acids seemed to be the causing factor for this decrease. Furthermore, the oxidative stability of model systems enriched with photoautotrophic microalgae was significantly higher than of those enriched with heterotrophic microalgae. It can therefore be concluded that photoautotrophic microalgae low in initial free fatty acid content are a promising source of n-3 LC-PUFA in thermally processed acidic food systems. ispartof: FOOD CHEMISTRY vol:268 pages:441-450 ispartof: location:England status: Published online

The practice of pod storage (PS) has been applied in many cocoa producing countries, especially by Ghanaian farmers over the years. However, the study of PS has not received much attention, hence, until now, its potential impact on specific flavor precursor development and implications on the flavor of cocoa beans still remains uncovered. The study was therefore aimed at exploring this possibility through physico-chemical and flavor precursor analyses, carried out on equally fermented and dried pod stored (0, 3 and 7 days) Ghanaian cocoa beans. Flavor analysis was also conducted on equally roasted pod stored cocoa beans. Through visual assessment of the pods, pulp and beans, the compelling impact of PS on fermentation index (FI) and nib acidity could be demonstrated by the various biochemical and physical changes such as respiration, moisture reduction, and cellular degradation, occurring during the process. Whereas the entire reaction of sugar degradation may be deemed complex, a clear relationship between the FI, nib acidity and the glucose content was observed. Also, PS was found to increase with marginal increase in total reducing sugars (glucose and fructose). Although the concentration of free amino acids was directly proportional to the duration of PS, within the framework of this study, a significant difference (p

Lipid oxidation is one of the main causes of food deterioration, resulting in the loss of nutritional properties and the formation of unwanted aroma properties. Both for scientific and industrial purposes there is a need for accelerated lipid oxidation tests in food research. The conventional thermally-based accelerated lipid oxidation protocols are known to insufficiently correlate to the realistic oxidation mechanisms. Recent studies have investigated the application of an innovative non-thermal plasma technique as a promising alternative approach. The produced reactive oxygen species in non-thermal plasma enabled to accelerate the lipid oxidation process, with a more accurate prediction of antioxidative properties, thus leading to a higher correlation with the naturally oxidized product. In order to obtain more profound insights in the plasma-induced chemistry, a profound parameter study was performed by studying the impact of applied voltage, plasma gas composition, distance between nozzle and sample surface, ambient gas composition and treatment time. Using analytical tools (HS-SPME-GC-MS) on one hand, combined with statistical interpretations (PCA/SIMCA/HCA) on the other hand, a selection of the most promising parameter settings was done. For this parameter study, pure oleic acid was used as a model matrix. In the naturally aged sample, typical oxidation products have been found, such as heptanal, octanal, nonanal, (E)-nonenal, etc… Comparing the different plasma types (argon, argon/O2 and argon/H2O) in different surrounding gas compositions (air, argon) showed most promising results for Ar/O2 in Ar atmosphere. A correlation up to 82 % was found between the naturally aged oleic acid sample and the plasma treated sample. publisher: Elsevier articletitle: Controlled accelerated oxidation of oleic acid using a DBD plasma: Determination of volatile oxidation compounds journaltitle: Food Research International articlelink: http://dx.doi.org/10.1016/j.foodres.2015.11.028 content_type: article copyright: Copyright © 2015 Elsevier Ltd. All rights reserved. ispartof: Food Research International vol:79 pages:54-63 status: published

In this study the quality of 26 fermented cocoa beans from 4 different countries (Vietnam, Indonesia, Peru and Ghana) is assessed by means of both a compositional analysis (amino acids, reducing sugars, polyphenols and lactic acid) and profiling of their volatile aroma composition (Mass Spectrometry (MS)-fingerprinting and Headspace-solid Phase Micro-extraction-Gas Chromatography–Mass Spectrometry (HS-SPME-GC–MS)) following high roasting processing (30 min at 150 °C). Compared with the labour-intensive measurement of cocoa precursors, MS-fingerprinting on the cocoa headspaces appeared to be a very powerful and fast classification technique. Different cocoa groups were researched having unique organoleptic characteristics which were affected by fermentation, roasting conditions and geographical origin. A clear separation of fine flavour cocoa (Criollo variety), well fermented/roasted cocoa and low quality cocoa could be made. Additionally, the clustering was confirmed by more conventional HS-SPME-GC–MS aroma analyses on the cocoa samples. Several markers for the bean origin/quality were identified. Roasting degrees were also calculated based on typical pyrazine ratios.

Non-thermal plasma technology has been investigated for the first time to induce realistic lipid oxidation reactions. Today accelerated lipid oxidation methods are often temperature-based although it is known that widely divergent kinetics and side-reactions occur as a function of the employed temperature. In this paper both a thermally-based reference test and experiments using three types of plasma (Ar plasma, oxygen-doped Ar plasma, water-doped Ar plasma) were investigated. Treatment of fresh reference vegetable oil with pure argon plasma did not induce lipid oxidation reactions. Contrarily, a short treatment with both 0.3% O2/Argon and 0.3% H2O/Argon plasmas resulted in the production of several oxidation products that were also identified in naturally oxidized oil. MS-fingerprinting analyses, supported by the degree of difference sensory testing, indicated that current plasma configuration induces changes that are different from these measured in naturally aged vegetable oil. Chemical profiling of the secondary volatile lipid oxidation products showed that atomic oxygen resulted mainly in aldehyde production, while singlet oxygen induced the formation of 2-pentyl furan. Vegetable oils exposed to Ar/0.3% H2O plasma were characterized by lower amounts of oxidation products. It can be concluded that plasma technology is an innovative and a promising technique to investigate the role of individual reactive species and/or unravel oxidation reaction pathways, with the potential to become a more representative accelerated food aging technique.

The unique impact of roasting conditions on the aroma quality of cocoa beans has been demonstrated in many studies. However, information on the additional impact of pod storage (PS) and its combined effect with roasting temperature (RT) is unknown. Hence, this study sought to elucidate the collective contribution of these post-harvest/process parameters on the aroma profiles of cocoa liquors produced from Forastero cocoa beans. The beans had been subjected to different treatments following a 3 × 4 full factorial experiment, consisting of PS (0, 3, 7 days) and RT (100, 120, 140, 160 °C). Statistical analysis of the results from HS-SPME-GC-MS revealed significant (p .05) impact of both PS and RT as well as their interaction effects on the ten groups of volatiles (acids, alcohols, esters, terpenes, aldehydes, ketones, pyrazines, furans, pyrroles and others) and their overall aroma concentration. An exception was however noted for aldehydes, where the total concentration was only significantly (p .05) influenced by the individual effects of PS and RT. A subsequent clustering of the liquors, first on the basis of all identified volatiles, then, on the basis of the odor-active volatiles, also revealed similar pattern where liquors with high RT's possessed more volatiles with higher concentrations and vice versa. More so, it seemed that no or very minimal PS treatment was necessary for preserving more aromatic volatiles with typically fruity, floral or spicy flavor notes, whereas, for liquors with volatiles exhibiting more cocoa, chocolate, nutty and roasted flavor notes, prolonged PS (3 days) treatment was required. These findings are expected to challenge the status-quo, specifically in the conventional ways through which the aroma potential of 'bulk' cocoa may be steered. On the one hand, the idea of manipulating PS treatment and roasting conditions may indeed consolidate the possibility of creating diverse and/or distinct aroma profiles from the same 'bulk' cocoa beans, whereas, on the other hand, it raises the question whether the Ghanaian cocoa beans - being described as 'bulk' cocoa - could be a consequence of prolonged pod storage treatment.

Bio-recalcitrant micropollutants are often insufficiently removed by modern wastewater treatment plants to meet the future demands worldwide. Therefore, several advanced oxidation techniques, including cold plasma technology, are being investigated as effective complementary water treatment methods. In order to permit industrial implementation, energy demand of these techniques needs to be minimized. To this end, we have developed an electrical discharge reactor where water treatment by dielectric barrier discharge (DBD) is combined with adsorption on activated carbon textile and additional ozonation. The reactor consists of a DBD plasma chamber, including the adsorptive textile, and an ozonation chamber, where the DBD generated plasma gas is bubbled. In the present paper, this reactor is further characterized and optimized in terms of its energy efficiency for removal of the five pesticides α-HCH, pentachlorobenzene, alachlor, diuron and isoproturon, with initial concentrations ranging between 22 and 430 μg/L. Energy efficiency of the reactor is found to increase significantly when initial micropollutant concentration is decreased, when duty cycle is decreased and when oxygen is used as feed gas as compared to air and argon. Overall reactor performance is improved as well by making it work in single-pass operation, where water is flowing through the system only once. The results are explained with insights found in literature and practical implications are discussed. For the used operational conditions and settings, α-HCH is the most persistent pesticide in the reactor, with a minimal achieved electrical energy per order of 8 kWh/m3, while a most efficient removal of 3 kWh/m3 or lower was reached for the four other pesticides.

Because of animal welfare issues, the voluntary ban on surgical castration of male piglets, starting January 2018 was announced in a European Treaty. One viable alternative is the fattening of entire male pigs. However, this can cause negative consumer reactions due to the occurrence of boar taint and possibly lead to severe economic losses in pig husbandry. In this study, headspace solid phase microextraction (HS-SPME) coupled to GC-MS was used in the development and optimization of a candidate method for fast and accurate detection of the boar taint compounds. Remarkably fast extraction (45s) of the boar taint compounds from adipose tissue was achieved by singeing the fat with a soldering iron while released volatiles were extracted in-situ using HS-SPME. The obtained method showed good performance characteristics after validation according to CD 2002/657/EC and ISO/IEC 17025 guidelines. Moreover, cross-validation with an in-house UHPLC-HR-Orbitrap-MS method showed good agreement between an in-laboratory method and the new candidate method for the fast extraction and detection of skatole and androstenone, which emphasizes the accuracy of this new SPME-GC-MS method. Threshold detection of the boar taint compounds on a portable GC-MS could not be achieved. However, despite the lack of sensitivity obtained on the latter instrument, a very fast method with run-to-run time of 3.5min for the detection of the boar taint compounds was developed.

In recent years adulteration of pure extra virgin olive oil (EVOO) with other types of vegetable oils has become an important issue. In this study, non-thermal plasma (NTP) is investigated as an innovative preparative analytical technique enabling classification of adulterated olive oil from an ascertained authentic batch of olive oil in a more sensitive manner. Non-thermal plasma discharges are a source of highly oxidative species such as singlet oxygen, and atomic oxygen. It was assumed that NTP-induced oxidation triggers unique lipid oxidation mechanisms depending on the specific composition of the oil matrix and minor constituents. In this work EVOO samples were adulterated with sunflower oil (1–3%) and submitted to NTP treatment. Results showed that while untreated samples could not be classified from the authentic olive oil reference, NTP treatments of 60 min (Ar/O 2 0.1%) on the oil batches resulted in the formation of a unique set of secondary volatile lipid oxidation products enabling classification of adulterated oil samples.

Today, the cocoa industry is in great need of faster and robust analytical techniques to objectively assess incoming cocoa quality. In this work, inline roasting hyphenated with a cooled injection system coupled to a gas chromatograph-mass spectrometer (ILR-CIS-GC-MS) has been explored for the first time to assess fermentation quality and/or overall aroma formation potential of cocoa. This innovative approach resulted in the in-situ formation of relevant cocoa aroma compounds. After comparison with data obtained by headspace solid phase micro extraction (HS-SPME-GC-MS) on conventional roasted cocoa beans, ILR-CIS-GC-MS data on unroasted cocoa beans showed similar formation trends of important cocoa aroma markers as a function of fermentation quality. The latter approach only requires small aliquots of unroasted cocoa beans, can be automatated, requires no sample preparation, needs relatively short analytical times (

In recent decades, several types of persistent substances are detected in the aquatic environment at very low concentrations. Unfortunately, conventional water treatment processes are not able to remove these micropollutants. As such, advanced treatment methods are required to meet both current and anticipated maximally allowed concentrations. Plasma discharge in contact with water is a promising new technology, since it produces a wide spectrum of oxidizing species. In this study, a new type of reactor is tested, in which decomposition by atmospheric pulsed direct barrier discharge (pDBD) plasma is combined with micropollutant adsorption on a nanofiber polyamide membrane. Atrazine is chosen as model micropollutant with an initial concentration of 30 μg/L. While the H2O2 and O3 production in the reactor is not influenced by the presence of the membrane, there is a significant increase in atrazine decomposition when the membrane is added. With membrane, 85% atrazine removal can be obtained in comparison to only 61% removal without membrane, at the same experimental parameters. The by-products of atrazine decomposition identified by HPLC-MS are deethylatrazine and ammelide. Formation of these by-products is more pronounced when the membrane is added. These results indicate the synergetic effect of plasma discharge and pollutant adsorption, which is attractive for future applications of water treatment. publisher: Elsevier articletitle: Decomposition of atrazine traces in water by combination of non-thermal electrical discharge and adsorption on nanofiber membrane journaltitle: Water Research articlelink: http://dx.doi.org/10.1016/j.watres.2014.11.009 content_type: article copyright: Copyright © 2014 Elsevier Ltd. All rights reserved. ispartof: Water Research vol:72 pages:361-371 ispartof: location:England status: published

Food products enriched with healthier unsaturated fatty acids are more sensitive to lipid oxidation, leading to an overall quality deterioration and the development of unwanted aroma properties. To evaluate the oxidative stability a wide range of techniques has been described in literature, of which most are thermally based. These unrealistic test conditions result in the induction of deviating oxidation chemistry compared to that observed during ambient storage. Non-thermal plasma technology is capable to generate a wide range of highly reactive oxidative species (e.g. atomic oxygen, hydroxyl radicals, singlet oxygen) while maintaining ambient temperatures. For the first time, a DBD-plasma jet (Ar/0.6% O2) is used on fish oil samples as a faster and more realistic accelerated lipid oxidation method. This paper critically evaluates both a thermal as a non-thermal plasma based accelerated oxidation protocol using naturally aged fish oil as reference. Experiments were done using both virgin, as alpha-tocopherol-enriched fish oil samples. Secondary lipid oxidation volatiles were measured using HS-SPME-GC-MS. Both accelerated oxidation techniques induced the formation of typical lipid oxidation markers (e.g. 2-propenal, (E)-2-pentenal, heptanal), however in both cases significant differences were observed compared to the naturally aged fish oil. On the other side, nonthermal plasma correctly predicted an antioxidative effect when 1000 μg/g alpha-tocopherol was added to the fish oil, while thermally based tests resulted in the induction of prooxidative chemistry. Despite the differences with naturally aged fish oil, several non-thermal plasma characteristics (reactor configuration, gas feed mixture, power source, …) can be fine-tuned to evolve towards a technology that is capable to accelerate lipid oxidation in a highly realistic manner. publisher: Elsevier articletitle: Critical evaluation of non-thermal plasma as an innovative accelerated lipid oxidation technique in fish oil journaltitle: Food Research International articlelink: http://dx.doi.org/10.1016/j.foodres.2015.03.037 content_type: article copyright: Copyright © 2015 Elsevier Ltd. All rights reserved. ispartof: Food Research International vol:72 pages:115-125 status: published

Sorption of volatile organic compounds on the inner surface of polymer sampling bags leads to important underestimations of the real headspace concentration. Introducing a wide range of volatiles in a two-phase system containing Nalophan, revealed that recoveries decreased down to 57% in a period of 22 hours. In this work a Phase Ratio Variation approach is investigated to quantify the degree of scalping, and thus enabling to compensate for sorption phenomena. This method requires limited measurements, without the need for time-consuming calibrations. By spiking identical amounts of volatiles in three two-phase systems, each having unique polymer volume/mass ratios, individual partitioning coefficients could be experimentally determined for a wide range of compounds. Additionally, a correlation was found between these partitioning coefficients and the liquid molar volume for a number of aliphatic, aromatic and oxygenated compounds. ispartof: Environmental Science and Pollution Research vol:22 issue:14 pages:11067-11075 ispartof: location:Germany status: published

In this work, degradation of the anthraquinonic dye Acid Blue 25 by non-thermal plasma at atmospheric pressure with and without photocatalyst is investigated. Titanium dioxide (TiO2) is used as a photocatalyst. The dye degradation by plasma in the presence of TiO2 is investigated as a function of TiO2 concentration, dye concentration and pH. The degradation rate is higher in acidic solutions with pH of 2 to 4.3, especially at pH 2, and decreases to 0.38 mg L-1 min-1 with the increase of pH from 2 to 5.65. A similar effect is observed in basic media, where a higher degradation rate is found at pH = 10.3. The degradation rate increases in the presence of TiO2 compared to the discharge without photocatalysis. The results show that the degradation of the dye increases in the presence of TiO2 until the catalyst load reaches 0.5 g L-1 after which the suppression of AB25 degradation is observed. The results indicate that the tested advanced oxidation processes are very effective for the degradation of AB25 in aqueous solutions.

Due to their high content of polyunsaturated fatty acids, antioxidants, and proteins, microalgae hold a lot of potential for nutritional applications. When microalgae are integrated into foodstuffs, the aroma is an important aspect to consider. In this study the aroma properties of microalgae were studied by correlating data on the volatile composition with sensory evaluations. Four species of marine microalgae ( Botryococcus braunii, , Rhodomonas , Tetraselmis species, and Nannochloropsis oculata ) and one fresh water microalga ( Chlorella vulgaris ) were investigated. Multivariate data processing revealed that microalgal samples having a seafood-like odor character contain high levels of sulfuric compounds (dimethyl disulfide, dimethyl trisulfide, and methional), diketones, α-ionone, and β-ionone. Fresh green, fruity flavors were linked with typical aldehydes such as 2,4-alkadienals and 2,4,6-alkatrienals. The presence of these compounds in fresh microalga pastes is explained by aroma formation mechanisms such as enzymatic lipid oxidation, enzymatic and chemical degradation of dimethylsulfoniopropionate (generating dimethyl sulfide), phenylalanine (generating benzaldehyde), and carotenoids (generating ionones).

Microalgae are the primary producers of omega-3 LC-PUFA, which are known for their health benefits. Their oil may thus be a potential alternative for fish oil. However, oxidative and hydrolytic stability of omega-3 LC-PUFA oils are important parameters. The purpose of this work was therefore to evaluate these parameters in oils from photoautotrophic microalgae (Isochrysis, Phaeodactylum, Nannochloropsis gaditana, and Nannochloropsis sp.) obtained with hexane/isopropanol (HI) and hexane (H) and compare them with commercial omega-3 LC-PUFA oils. When the results of both the primary and secondary oxidation parameters were put together, it was clear that fish, tuna, and heterotrophic microalgae oil are the least oxidatively stable oils, whereas krill oil and the microalgae oils performed better. The microalgal HI oils were shown to be more oxidatively stable than the microalgal H oils. The hydrolytic stability was shown not to be a problem during the storage of any of the oils.

Plasma driven catalysis is a promising technology for waste gas treatment characterized by higher energy efficiencies, high mineralization rates and low by-product formation. The combination of heterogeneous catalysts with non-thermal plasma can be operated in two configurations: positioning the catalyst in the discharge zone (in-plasma catalysis) or downflow the discharge zone (post plasma catalysis). In a first part of the review, changes of plasma properties resulting from the introduction of catalyst material are discussed. It has been reported that discharge types can even change. Accordingly, it was reported that microdischarges are formed within the catalyst pores. Changing plasma characteristics can eventually result in enhanced production of new active species, increasing the oxidizing power of the plasma discharge. In a second part, it is discussed that plasma discharges also affect catalyst properties such as a change in chemical composition, enhancement in surface area or change of catalytic structure. These phenomena partially explain why catalyst adsorption kinetics of airborne pollutants are affected when exposed to plasma discharges. It is also reviewed that the synergy of combining plasma with catalysts can not only be attributed to the production of new reactive species. Also plasma photon emission or thermal hot-spots can initiate catalytic pollutant oxidation reactions. To conclude, an overview of recently published manuscripts concerning plasma catalysis for volatile organic compounds abatement is given. It is also discussed why heterogeneous plasma catalysis has high potential for the simultaneous abatement of NO x and hydrocarbons.

Solid-phase dynamic extraction (SPDE) belongs to the most innovative sample preparation and enrichment techniques. However, there is still a lack of knowledge on the fundamentals of SPDE and its applicability in the field of environmental monitoring. A homemade sampling device is constructed to make a detailed study of SPDE kinetics for toluene extraction. It proved that at least 50 aspirating and dispensing cycles were necessary to obtain toluene equilibration between gas and coating phase. A mechanistic model is proposed to explain that in every dispensing step during SPDE, significant losses of retained analytes (up to 48%) occur due to desorption processes. A new accelerated solid-phase dynamic extraction procedure (ASPDE) has been developed that avoids dispensing stages during extraction. The resulting extraction time proves to be 1.7 min, being a reduction by a factor of 37 compared with the SPDE extraction time. ASPDE proved to have high potential in ambient/indoor air monitoring. The limit of detection for toluene was determined to be 56 ppb v , i.e. a factor of respectively, 6 and 35 lower than obtained with SPME and conventional headspace sampling with gas syringe.