An assessment of the effect of cinnamon spice on cocoa nibs Theobroma cacao L An approach to change flavour in stored roasted cocoa nibs
Fine flavours in chocolate are influenced by factors such as cacao variety, growing environment, post harvest processing and chocolate manufacturing processes. The objective of this experiment was to develop a method to enhance the flavour of cocoa nibs without affecting their inherent fine flavours. Concentration of cinnamon, method of packaging, and exposure time were manipulated to obtain a unique ancillary spice note as detected via descriptive sensory evaluation of cocoa liquor processed from the cinnamon infused cocoa nibs. Increased concentration enhanced the detection of cinnamon flavour, more so under vacuum packaging, while simultaneously reducing the perception of an undesirable note. This study shows that addition of ancillary spices to a mass of nibs can enhance the taste experience, allowing for novel favourable and unique liquor products. This method has particular potential for small to medium size chocolate makers and chefs. Introduction Cocoa beans are categorized globally into two groups, "fine or flavour" cocoa and bulk cocoa. Fine or flavour cocoa beans are generally obtained from cocoa trees of Criollo or Trinitario ancestry. They are characterized by desirable ancillary flavour notes such as floral and fruity, with a robust chocolate flavour. In contrast, bulk cocoa has a robust chocolate note with no significant ancillary notes. Cocoa nibs are fermented, dried, roasted and crushed cocoa beans [1] Currently, there is an increase in demand for "fine or flavour" cocoa beans and nibs largely due to the buoyant craft chocolate and culinary industry that uses it to produce exclusive chocolates and chocolate products. This craft industry uses innovations through the transference of novel flavours into cocoa and therefore can provide a competitive advantage in an increasingly competitive marketplace. Cocoa or chocolate flavours can be enhanced through the addition of direct spices and flavouring during conching but this may give negative mouthfeel properties. Desirable flavours can result in unique flavour notes and thus further enhance the quality of cocoa and the potential price it can fetch in the market. Bio generated atmospheres or vacuum storage demonstrated a positive impact on stored cocoa beans [2] Little work has been done to show the significance of vacuum storage or its influence on flavour infusion on "fine or flavour" roasted cocoa nibs. Aromas could potentially be transferred onto cocoa by a process known as mass transfer [3] By manipulating concentration and distance one should be able to affect a flavour change in stored roasted cocoa nibs validated through descriptive sensory evaluation. Descriptive sensory evaluation of cocoa liquor has been used as a tool to judge cocoa bean quality. A major strength of descriptive sensory evaluation is that it can link instrumental measurements of quality with consumer acceptance [4] An optimised Matthew Escalante et al. 116 protocol for descriptive sensory evaluation was developed to quantify different flavour attributes of cocoa liquors in Trinidad and Tobago [1] The overall objective of this work is, therefore, to develop a standardised method for cocoa nib infusion with cinnamon spice aroma to be used by small to medium size chocolate makers and chefs. Experimental Nib and cocoa liquor preparation Cocoa beans from the International Cocoa Gene Bank Trinidad (ICGT) were selected and used for the experiment. Roasting of beans was done according to Sakha et al. [1] After roasting, beans were cooled to room temperature on cooling racks for further processing. Cocoa beans were broken using a cocoa breaker to an average size of 0.2 0.5 cm and collected into neutral and non odorous plastic containers. The broken beans were then winnowed and winnowed nibs were manually fine cleaned using stainless steel forceps. Cocoa nibs were packaged based on the experiment design below and stored at 22degC room temperature. Table 1: Overview of the experimental set up and design. Experiment Replication Treatments of ingredient infusion Storage method Levels of infused ingredient in 100 grams of nibs Sampling days Two replicates (0 grams cinnamon was not repeated in experiment) Cinnamon sticks (placed in the bags with nibs) Vacuum (1) sealable bags Aerated (2) sealable bags 2 grams 10 grams 25 grams 0 grams 3, 7, 14, 28, 56 Each vacuum sealed and aerated sample bag was opened and 50 g of nibs were removed and used to make liquor. Bags with the remainder of the nibs were resealed. Nibs were broken down using a Magic Bullet(r)USA blender. The blender was pulsed 9 times for one second and 3 times more for 3 seconds. The ground sample was placed in a Cocoa Town(r) USA mini 500g bowl to be milled for one and a half hours in a Cocoa Town(r) ECGC 12SLTA Melanger. The cocoa paste or liquor was then transferred to a sterile plastic cup, which was labelled with the date and sample information. The cups were then sealed with tape and placed in a freezer at 4 degC.