Effects of time and temperature during melanging on the volatile profile of dark chocolate

Abstract

Chocolate made from small-batch production is known for distinct sensory properties that differentiate its products from large-scale production. Specifically, small-batch processing includes a melanging step, a chocolate refining (a process involving time and temperature to refine texture and flavor) process that occurs in a stone wet-grinder. Chocolatiers understand that melanging is essential to flavor and overall quality, however the influence of melanging on the aroma chemistry of the finished chocolate is anecdotal and largely uncharacterized. Here, we evaluated the effects of time and temperature of melanging on the volatile chemistry of the finished chocolate. Specifically, chocolate aroma was profiled using HS/SPME–GC–MS for three different time and temperature combinations. A total of 88 compounds were annotated by mass spectrometry and included a diverse set of chemical classes such as pyrazines, aldehydes, terpenes, alcohols, esters, and ketones. Analysis of variance (ANOVA), principal component analysis (PCA), and partial least squares analysis (PLS) revealed that the overall aroma profile was influenced by the type of melanging, and time had a greater effect than temperature. Example compounds affected by time include 2-methylpropanal, dimethyl sulfide, and benzaldehyde. Particle size was also measured for each sample. Majority particle size was found to be below 25 microns generally at all time points beyond 8 h. Analysis showed significant p-values for the temperature variable for several compounds, but significant p-values for the time variable were apparent for a greater number of compounds. For compounds which showed dependency on both time and temperature, the p-value for the time variable was much smaller in most cases. Both PCA and OPLS analyses suggested the same trends. These data support that time is a critical factor in determining the aroma chemistry of chocolate and affects a diverse set of known flavor active compounds.

The role of conching in chocolate flavor development: A review

“…As a result, conching shifts their balance and rearranges the combinatorial code of chocolate's retronasal aroma. Although more severe time and temperature combinations facilitate the removal of volatile fatty acids with disagreeable odor, they can also harm delicate and nuanced flavors, such as fruity and floral notes, associated with low‐boiling alcohols, esters, ketones, and other chemicals, especially in longer conching cycles (above 6–8 h) (Clark et al., 2020; Owusu et al., 2012; Tran et al., 2016). This trade‐off should be considered by manufacturers when sourcing raw materials and setting conching parameters in order to achieve expected flavors, especially in premium chocolates with high cocoa content.…”

Food Metabolomics

“…Clark et al focused on the melting process in chocolate production, and revealed variation of chocolate components, especially aroma components, under various conditions by metabolomic analysis using GC-MS (22). The study reported that the aroma components of chocolate change in a time-dependent manner during melting and that the variability of the components differs depending on the volatility of the compounds.…”

The Evaluation of Dark Chocolate-Elicited Emotions and Their Relation with Physico Chemical Attributes of Chocolate

“…Chocolate taste and aroma is directly connected to the contents of volatile aroma compounds [52]. Such VC as alcohols, sulfides, and ketones may have a significant impact on chocolate taste and odor [53]. It has been reported that the presence of acetic acid, 2-methylpropanoic acid, 3-methylbutanoic acid and hexanoic acid was observed in dark chocolate [54].…”