Decoding the Fine Flavor Properties of Dark Chocolates

Physically Modified Plant Oils as Alternatives to Palm Fat: Effects on Physical and Flavour Properties of Chocolate Fillings

Palm and palm kernel oils are extensively utilised in food processing due to their unique properties, such as their semi-solid consistency at room temperature. However, growing environmental and social concerns regarding palm oil production have prompted the industry to seek sustainable alternatives to tropical or hydrogenated fats. This project investigated the use of plant oils and their emulsified and crystallised forms as potential substitutes for palm fat in light and dark chocolate fillings, with an emphasis on single-origin ingredients to align with clean-label trends. The emulsions were assessed for viscosity, firmness, colour, and key flavour and aroma profiles. Results demonstrated that palm fat alternatives performed effectively in dark chocolate fillings, with non-emulsified recipes achieving firmness comparable to palm fat. In contrast, light chocolate fillings exhibited reduced firmness at higher inclusion rates of alternatives, and emulsified products were prone to flocculation. Notably, pure oil formulations delivered promising outcomes at lower inclusion rates, as the firmness could be raised by 22.0%, likely due to vegetable oil and cocoa butter interactions influencing crystal morphology. Substituting palm oil with sunflower oil, either crystallised or emulsified, did not compromise the overall flavour. Future investigations should determine the maximum feasible level of palm fat substitution and investigate the potential of adding higher amounts of waxes and emulsifiers to enhance crystal formation and firmness.

Metabolomic insights into flavour precursor dynamics during fermentation of cacao beans cultivated in diverse climatic production zones in Colombia

The market for flavour superior quality cacao provides significant economic and non-economic benefits to farmers. Flavor precursor metabolites, formed during various post-harvest stages, are crucial for developing superior sensory attributes. However, identifying these metabolites and understanding how climate variations and post-harvest practices influence them remains a challenge. This study investigates how the fermentation methodology applied and climate conditions in different zones of the cacao beans producing region of Arauca - Colombia, influence the metabolomic profile of cacao beans and their flavour precursor metabolites. Untargeted metabolomic analysis was performed by UHPLC-ESI-Orbitrap-MS on cacao beans fermented for 0, 24, 48, 72, 96, and 120 h from 9 production zones. The PLS-DA model highlighted that the metabolomics fingerprint changes through fermentation time. Among the most discriminant metabolites, 18 oligopeptides, sucrose, glucose, fructose, flavanols, and acids were tentatively identified. The chemometric analysis showed that fermentation time has a significant impact on the metabolomic profile of cacao beans, while agroclimatic conditions had a minor influence. Metabolomic analyses defined 96 h as the optimal fermentation time to maximize the amount of aroma precursors. Metabolomic analyses identified 96 h as the optimal fermentation time to maximize the amount of aroma precursors across all 9 cacao production zones evaluated. This study underscores the central role of fermentation in shaping flavor precursors, and contributes to the development of new approaches for cacao processing based on the tracking of biochemical and functional compounds (quality biomarkers).

Foaming properties and olfactory profile of fermented chickpea aquafaba and its application in vegan chocolate mousse

Aquafaba, the cooking water of chickpeas and other pulses, is used as a vegan egg white substitute because of its favorable technofunctional properties. Nonetheless, its application is often restricted by a "beany" flavor and poor foaming properties compared to egg white. To overcome these limitations, aquafaba was fermented with two edible basidiomycetes. During the fermentation process, foaming properties were measured and analyzed. Furthermore, the aroma change was described by sensory experts. Based on these results, the optimal fermentation day was selected for each mushroom and sensory profiling was conducted. Subsequently, chocolate mousse was prepared from fermented aquafaba and profiled as well as tested in an acceptance test. Aquafaba profiling revealed significantly lower scores (α = 5%) for "beany" odor in fermented samples. Chocolate mousse produced with fermented aquafaba was described as less "beany" but more "chocolatey" and "cocoa-like" in smell and taste, and more "sweet" in taste. The texture of mousse prepared with fermented aquafaba was more "fluffy/light/porous" and "soft" but less "homogenous" than mousse with unfermented aquafaba. The consumer test showed high overall liking for all mousses. The research described in this study revealed for the first time promising aroma changes based on fermentation in aquafaba and demonstrated improved foaming properties. Thus, fermentation can be considered a useful tool to enhance the quality of aquafaba and thus expand its fields of application.

Unveiling the cocoa-carob flavour gap in dark chocolates via instrumental and descriptive sensory analyses

Roasted carob pulp (Ceratonia siliqua) is a cocoa substitute known for its faint cocoa-like resemblance. However, the cocoa-carob flavour gap remains poorly uncharacterised. This study aimed to elucidate the sensory and molecular aspects of this flavour gap in a 70 % dark chocolate formulation via a two-pronged instrumental-sensorial approach. Descriptive Sensory Analysis (DSA) revealed carob-based chocolate was significantly sweeter, less sour and astringent than conventional dark chocolate due to the high total sugar content (45-50 % DM; HPLC/RID), low titratable acidity and tannin content, respectively. As for aroma, a distinct, albeit weak, cocoa-like aroma was present in carob-based chocolate. HS-SPME-GC-MS/FID revealed this was attributed to branched-chain Strecker aldehyde generation during roasting (2-methylbutanal, 1.17 μg/g; 3-methylbutanal, 2.89 μg/g). Notably, there was a distinct lack of alkylpyrazines. Additionally, a distinct woody, tree bark-like odour was uniquely associated with carob-based chocolates. This was due to furfural generation during roasting (2.33 μg/g). In conclusion, the aroma and taste gap between cocoa and carob was successfully characterised in this study. These findings substantiate the potential of carob application in chocolate manufacturing, thus empowering confectioners to make evidence-based decisions when evaluating cocoa substitutes.

Molecular Aroma Composition of Vanilla Beans from Different Origins

The demand for natural Vanilla has increased rapidly, creating the need for more potential sources of high-quality Vanilla essence. Understanding the geographical influences on the aroma profile of Vanilla is essential. This study demonstrates the first comparative analysis of odorant compositions in the three most important Vanilla varieties: Vanilla planifolia, Vanilla pompona, and Vanilla tahitensis from different origins. Following the screening for odor-active molecules through gas chromatography-olfactometry and aroma extract dilution analysis (GC-O and AEDA), selected compounds were quantified using stable isotope dilution assays (SIDA) and their dose over threshold values (DoTs) were calculated. Vanillin was confirmed as the most important odor-active compound due to its highest DoT value, especially in the V. planifolia sample. Meanwhile, 4-methoxybenzyl alcohol and 4-methoxybenzaldehyde showed higher DoT factors than vanillin in V. pompona and partially in V. tahitensis samples. This indicates their role as discriminative odorants for these varieties. The heightened DoT values of 3-hydroxy-4,5-dimethyl-2(5H)-furanone in Uganda Vanilla samples unveil geographical influences on the odorant profile within V. planifolia species. Additionally, 2-methyl-3-(methyldithio)furan was identified for the first time in Vanilla samples with diverse DoT values from different species and origins.

Influences of Depulping, Pod Storage and Fermentation Time on Fermentation Dynamics and Quality of Ghanaian Cocoa

This study investigated the impact of the depulping of cocoa beans after pod opening, as well as the influences of pod storage (PS) and fermentation time on the fermentation dynamics and the overall quality of beans and liquors made thereof. Twelve variations were conducted in three experimental runs (with/without depulping; 1-/3-day PS; and fermentation times of 3, 4, 5, 6 or 7 days). Fermentation dynamics (e.g., temperature and pH) and the quality of dried beans (e.g., cut-test and fermentation index) and liquors (sensory assessment, quantification of cocoa key-odorants and tastants) were investigated. It was demonstrated that 17-20% of cocoa pulp, relative to the total bean-pulp-mass weight, could be mechanically removed without negatively affecting the bean quality. No significant differences were found in the percentages of well-fermented beans after 5-6 days fermentation with 1-day PS, resulting in 49 ± 9% with, and 48 ± 12% without depulping. There were no significant differences in key tastants present in the liquors; however, significantly less volatile acids and esters were found when liquors were produced from 5-6 day-fermented depulped beans, with 1-day PS, without negatively affecting the sensory profiles. This strategy allows producers to maximize the cacao fruit's value by integrating part of the pulp into the cocoa value chain.

Exploration of carbonyl compounds in red-fleshed kiwifruit wine and perceptual interactions among non-volatile organic acids

Carbonyl compounds are vital constituents that contribute to the flavor profile of alcoholic beverages. We examined 3-nitrophenylhydrazine as a derivatizing reagent for the measurement of 34 carbonyl compounds using UPLC-MS/MS. Adding formic acid and sodium acetate to the mobile phase significantly enhanced the detection limit of carbonyl compounds. The technique exhibited a notable extraction efficiency, yielding recovery percentages ranging from 83.6% to 117.1%, coupled with exceptional sensitivity, as evidenced by detection limits spanning from 0.07 μg/L to 4.80 μg/L. The relative standard deviation was <6.9%, indicating the precision and reliability of the analytical methodology. The method was verified by analyzing carbonyl compounds from red-fleshed kiwifruit wine. Furthermore, sensory assessment revealed that the amalgamation of tartaric acid, malic acid, and citric acid contributes to sour taste perception at sub-threshold concentrations through an additive interaction with supra-threshold non-volatile organic acids such as lactic acid and acetic acid.

Sensory attributes of fine flavor cocoa beans and chocolate: A systematic literature review

Fine flavor cocoa (FFC) is known for its unique flavor and aroma characteristics, which vary by region. However, a comprehensive overview of the common sensory attributes used to describe FFC beans and chocolate is lacking. Therefore, a systematic review was conducted to analyze existing literature and identify the most commonly used sensory attributes to describe FFC beans and chocolate. A systematic search of the Web of Science and Scopus databases was conducted in May 2023, and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to ensure transparency and reproducibility. This review summarizes the origins of cocoa and explores their unique flavor profiles, encompassing caramel, fruity, floral, malty, nutty, and spicy notes. Although some origins may exhibit similar unique flavors, they are often described using more specific terms. Another main finding is that although differences in sensory attributes are anticipated at each production stage, discrepancies also arise between liquor and chocolate. Interestingly, fine chocolate as the final product does not consistently retain the distinctive flavors found in the liquor. These findings emphasize the need for precise descriptors in sensory evaluation to capture flavor profiles of each origin. As such, the exploration of attributes from bean to bar holds the potential to empower FFC farmers and chocolate producers to effectively maintain quality control.

Toward Unified Flavor Quantitation in Cocoa-Based Products

Because food flavor is perceived through a combination of odor and taste, an analytical method that covers both dimensions would be very beneficial for mapping the consistent product quality over the entirety of a manufacturing process. Such a method, so-called "unified flavor quantitation", has been successfully applied to several different food products in recent years. The simultaneous detection of aroma and taste compounds by means of ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) enables the analysis and quantification of an enormously large number of compounds in a single run. To evaluate the limits of this method, chocolate, a high-fat, complex matrix, was selected. In 38 distinct commercial chocolate samples, 20 flavor-active acids, aldehydes, and sugars were analyzed after a simple, rapid extraction step followed by derivatization with 3-nitrophenylhydrazine using a single UHPLC-MS/MS method. The results obtained highlight the great potential of the "unified flavor quantitation" approach and demonstrate the possibility of high-throughput quantitation of key aroma- and taste-active molecules in a single assay.

Study on the Dynamic Changes in Non-Volatile Metabolites of Rizhao Green Tea Based on Metabolomics

The processing of tea leaves plays a crucial role in the formation of the taste of the resulting tea. In order to study the compositions of and changes in taste-related substances during the processing of Rizhao green tea, non-targeted metabolomics was used, based on UHPLC-Q Exactive MS. Totals of 529, 349, and 206 non-volatile metabolites were identified using three different detection modes, of which 112 secondary metabolites were significantly changed. Significant variations in secondary metabolites were observed during processing, especially during the drying stage, and the conversion intensity levels of non-volatile metabolites were consistent with the law of "Drying > Fixation > Rolling". The DOT method was used to screen tea-quality-related compounds that contributed significantly to the taste of Rizhao green tea, including (-)-epicatechin gallate, (-)-epicatechin gallate, gallic acid, L-theanine, and L-leucine, which make important contributions to taste profiles, such as umami and bitterness. Metabolic pathway analysis revealed that purine metabolism, caffeine metabolism, and tyrosine metabolism perform key roles in the processing of Rizhao green tea in different processing stages. The results of this study provide a theoretical basis for tea processing and practical advice for the food industry.

Cocoa quality: Chemical relationship of cocoa beans and liquors in origin identitation

In this study, HS-SPME-GC-MS was applied in combination with machine learning tools to the identitation of a set of cocoa samples of different origins. Untargeted fingerprinting and profiling approaches were tested for their informative, discriminative and classification ability provided by the volatilome of the raw beans and liquors inbound at the factory in search of robust tools exploitable for long-time studies. The ability to distinguish the country of origin on both beans and liquors is not so obvious due to processing steps accompanying the transformation of the beans, but this capacity is of particular interest to the chocolate industry as both beans and liquors can enter indifferently into the processing of chocolate. Both fingerprinting (untargeted) and profiling (targeted) strategies enable to decipher of the information contained in the complex dataset and the cross-validation of the results, affording to discriminate between the origins with effective classification models.

Link between Flavor Perception and Volatile Compound Composition of Dark Chocolates Derived from Trinitario Cocoa Beans from Dominican Republic

The chemical composition of dark chocolate has a significant impact on its complex flavor profile. This study aims to investigate the relationship between the volatile chemical composition and perceived flavor of 54 dark chocolate samples made from Trinitario cocoa beans from the Dominican Republic. The samples were evaluated by a trained panel and analyzed using gas chromatography-mass spectrometry (GC-MS) to identify and quantify the volatile compounds. Predictive models based on a partial least squares regression (PLS) allowed the identification of key compounds for predicting individual sensory attributes. The models were most successful in classifying samples based on the intensity of bitterness and astringency, even though these attributes are mostly linked to non-volatile compounds. Acetaldehyde, dimethyl sulfide, and 2,3-butanediol were found to be key predictors for various sensory attributes, while propylene glycol diacetate was identified as a possible marker for red fruit aroma. The study highlights the potential of using volatile compounds to accurately predict chocolate flavor potential.