Comparison of the Chemical and Sensorial Evaluation of Dark Chocolate Bars (original) (raw)

Key Aroma Compounds of Dark Chocolates Differing in Organoleptic Properties: A GC-O Comparative Study

Molecules

Dark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the chocolates’ headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi² test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, aci...

Dark chocolates organoleptic differences: a PTR-ToF-MS success story

2019

Aroma of dark chocolate depends on process and cocoa origin and variety. Repeated sensory analyses of standardized chocolates produced from various cocoa beans batches using a standard fabrication process allowed classifying them into four sensory categories. These categories were confirmed in a PTR-ToF-MS analysis of the volatilome of 206 chocolate samples through supervised multivariate data analyses (PLS-DA). Variable selection using dedicated methods pinpointed some volatile compounds important for the discrimination of the chocolates. Moreover, the nosespace of a subset of chocolates was measured by twelve assessors using PTR-ToF-MS with simultaneous determination of their sensory temporal profile (Temporal Dominance of Sensations methodology, TDS) to better explain the sensory categorization at a perception level. The two sets of data were analysed conjointly by defining an index of abundance of each detected aroma compound while a given attribute was dominant: the Abundance W...

Sensory description of dark chocolates by consumers

The Free Choice Profiling technique was applied to examine the analytical abilities of consumers (n ¼ 39) from two different locations (Vienna, Austria, and Dresden, Germany) to characterize plain dark chocolate. The cocoa content of the chocolate samples investigated in the study ranged from 60% to 75%, and General Procrustes Analysis and subsequent Principal Component Analysis were used for data analysis. Despite the different local background, both panels used an identical vocabulary for describing the samples; on average, only five descriptors (range: 3–13) were chosen by each assessor. Twenty nine different descriptors were generated by the Vienna panel, and 41 descriptors by the Dresden panel. Although differently assigned to Principal Components (PC) 1 and 2 which, together with PC3, accounted for approximately 85% of the total variance, the panels distinguished between the samples on a comparable level and used a comparable terminology with respect to type and frequency of the descriptors. A combined data evaluation revealed that the easily perceivable taste descriptors were useful for sample separation, whereas flavor descriptors only supported these data. With respect to mouthfeel, chocolate with a lower cocoa content was characterized as melting and creamy, whereas the product with the highest cocoa content was characterized as dry, mealy and sticky.

Sensory profile analysis of chocolate drinks using quantitative descriptive analysis (QDA)

E3S Web of Conferences

This study aims to analyse the sensory profile of a low-fat chocolate drink. The chocolate drink is being developed in laboratory of food science and technology department at Universitas Sebelas Maret. The QDA was applied to characterize the sensory profile of the developed product (sample D) and four commercial products (sample A, B, C, and E). 13 panellists were trained to evaluate those samples based on appearance, odour, flavour, basic taste and texture. Further, ANOVA was utilized to differentiate the samples, while PCA and Spider web were applied to analyse the sensory profile of the samples. The results showed that sample D was quite similar to sample A (dominated by cocoa aroma, cocoa flavour, sandiness, undissolved particles, colour, white-cream layer, thickness texture and bitter taste), whereas sample C had similar characteristic to sample E (represented by milky aroma, milky flavour, vanilla flavour and creamy texture). Meanwhile, sample B differed from others for repres...

Quality markers evaluation in chocolates with different cocoa content

International journal of health sciences

Quality assessment of cocoa-based food products (i.e., chocolate) reached increasing interest by scientific research, as it is rich in bioactive compounds (BCs) (i.e., catechins, methylxanthines, serotonin, etc.), which can have beneficial effects on human health (cardiovascular, immunomodulatory, mood regulator, etc.). Thus, the cocoa content may influence the quality of chocolate products. In this regard, the study aimed at a comprehensive evaluation of different BCs: biogenic amines (BAs), free fatty acids (FFAs), and antioxidant compounds (Total Polyphenols Content, TPC and Antioxidant Activity, AA), in chocolate samples with different cocoa contents (50%, 60%, 70%, 85%, 100%). By means of HPLC-UV/RF analysis, chocolates samples with higher cocoa content showed the highest concentration of serotonin, which represented the 25% of the total BAs concentration. Considering the total FFAs, unsaturated fatty acids (linoleic, linolenic and oleic) accounted for 30 to 50% in all chocolat...

Cocoa and Chocolate Products: The Sensory Characteristics That Affect Consumers’ Acceptance

Journal La Lifesci

This review describes the sensory characteristics of some cocoa and chocolate products which will later determine the acceptance of consumer. Cocoa beans are widely used as raw materials in many industrial sectors such as in food industries, cosmetics, and pharmaceutical. It will be further processed into several cocoa and chocolate products which performed certain characteristics. Relating to consumer acceptance, consumer will determine the product quality based on human senses. The evaluation of product using human senses is quite challenging since it present a set of particular and advantageous tools. Sensory evaluation promotes the scientific utilization and analysis of these tools. The aim of sensory evaluation in cocoa and chocolate product evaluation is to provide the information of the accepted characteristics based on human senses, which finally will contribute to the best quality of product expected by consumers.