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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.

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.

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.

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.

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.

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 (

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).