Improving Nutrient Density in Milk Chocolate Manufacturing

Transcription

1 Improving Nutrient Density in Milk Chocolate Manufacturing Abstract This proposal aims to gain authorization to complete research on the chocolate manufacturing process to improve the nutrient density of flavonoids in milk chocolate. The project will consist of researching the effects of altering parameters pertaining to the roasting, winnowing and milling processes of chocolate along with examining the effects of the amount and the types of other crucial ingredients used. Milk chocolate is highly consumed in the world, however, it has not been proven as beneficial as dark chocolate. Milk chocolate is the preferred chocolate choice for most Americans. The proposal includes a description of the project, the desired research methodology to acquire the desired measurements and data, research into the nutritional benefits of chocolate, a project schedule, the researcher s qualifications, and the assumed budget needed for the project. 1

2 Table of Contents Project Description 4 Literature Review 4 Methodology 6 Schedule of Work 7 Budget 7 Qualifications of Researcher 8 Anticipated Involvement of Faculty 8 Bibliography 8 2

3 Project Proposal This research project seeks to design a chocolate manufacturing process that enhances the nutritional benefits in the final milk chocolate product. Three sections of the chocolate manufacturing process, roasting, winnowing, and milling, will be the focus. This project will ultimately culminate in a new design for chocolate manufacturing that will optimize the nutrient content within milk chocolate. Currently, dark chocolate contains the highest quantity, up to 60%, of chocolate liquor, retaining the most nutritional benefits from the original cacao beans. However, dark chocolate is not as popular as milk chocolate due to the bitter taste of the chocolate liquor. In the United States, studies show that around 70% of Americans prefer milk chocolate over dark chocolate. Therefore, it is be beneficial to increase the nutritional content in milk chocolate, to counteract the unhealthy components of the chocolate. Roasting is required to develop the chocolate flavor and aroma, winnowing removes the husks from the cocoa bean, and milling grinds the cocoa nibs into the chocolate liquor, a non-alcoholic liquid. After each of the three processes, the nutritional content of the chocolate will be analyzed. By altering the time spent in each process and the temperature of each process, the optimal manufacturing process optimizing flavonoid content in the chocolate liquor exiting the milling process can be determined. The second phase will deal with the actual production of the chocolate, analyzing the individual ingredients and their effect on the final flavonoid content. The majority of milk chocolate is sugar, milk, and cocoa butter (fat), not the actual chocolate liquor, from the raw cacao beans. Therefore, with milk chocolate, flavonoid content is significantly less than dark chocolate due to the low amount of chocolate liquor and the high amount of other ingredients with small amounts of flavonoids. This project phase will culminate with a decision as to which combination and amount of chocolate liquor, milk, sugar, and cocoa butter optimizes flavonoid content while maintaining the milk chocolate taste. Literature Review Chocolate is a large consumer market. Chocolate has been around for a long time, with the first record going back to the Olmec civilization from BC [7]. While the chocolate seen in stores today may not be the same as what the Olmec civilization developed, chocolate has an extensive history. Today, the idea of what exactly is in a cacao bean and how beneficial these components are to one s health is becoming more significant In chocolate manufacturing, cacao beans undergo the same process, from growth to the manufacturing plant. After being harvested from the Theobroma cacao tree, the cacao beans are placed into boxes and fermented for five to seven days to bring out the flavor and aroma of the chocolate[6,7]. Before the cacao beans can be shipped to manufacturing plants, the fermented beans must be dried to create hard beans by removing moisture. Once the beans reach the plant, they undergo the roasting process in which the flavor characteristics are generated. These flavor characteristics are dependent on the amino acids and sugars available within the beans [3, 6, 7]. 3

4 To remove the shells or husks of the cacao beans, the winnowing process takes place. This process produces nibs, or the kernels of the beans, which are significantly smaller than the actual cacao bean. The nibs are then ground into a very refined grain in a process that generates heat. The amount of heat produced is enough to melt the cocoa butter within the beans, creating a liquid called chocolate liquor. Sugar, cocoa butter, cocoa solids, and milk are added to the chocolate liquor before it goes through the conching process. The conching process, which can last seventy-two to ninety-six hours, changes the flavor and texture of the chocolate mixture biochemically. Following conching, the chocolate is tempered though a repeated process of cooling and reheating. After the chocolate is tempered, it is ready to be placed into molds to create the desired product [3, 6, 7]. It is important to understand every aspect of the chocolate making process because each step influences the physical and chemical properties of the cacao bean and the end chocolate product. Chocolate has a highly complex structure. One of the most predominant issues in chocolate manufacturing is acquiring the correct crystal structure within the microstructure of chocolate. Being a polymorph structure, chocolate has six different crystalline forms, some of which are not as stable as others. Tempering assists in attaining a uniform stable crystalline structure, of form V. Form V is the most ideal due to the consumer appeal, the ease of manufacturing, and the favorable look [3, 5]. Tempering cools the liquid chocolate mixture to form the crystalline structures, then uses heat to melt the lower melting crystalline structures which will then form more stable forms upon re-cooling [3,6,7]. Along with process conditions affecting the physical and chemical properties of chocolate, the additional ingredients added to the chocolate liquor can also affect these properties. Chocolate is a non-newtonian fluid meaning that the viscosity is dependent upon shear force applied along with temperature and pressure of the liquid. When the cocoa solids are ground into a smaller particle size, the free cocoa butter available for flow through the chocolate is reduced, decreasing the viscosity [1, 3, 5, 7]. In order for a process to run smoothly, the chocolate needs to have a high viscosity. To improve viscosity of chocolate, the chocolate industry explored different types of sugar, milk, and varying amounts of cocoa butter. While chocolate is commonly consumed for pleasure, there are also nutritious benefits to consuming chocolate. Flavonoids, present in chocolate as flavanol, beneficially influence oxidative stress, vascular function, platelet function, and immune responses [2]. This antioxidant has many forms in chocolate, including the monomeric form of flavanols, epicatechin and catechin [1, 4]. Antioxidants are known to decrease the risk of heart disease [8]. Antioxidants in chocolate can also be found in multiple fruits and vegetables, sometimes having higher total phenol antioxidants in chocolate than in the fruits and vegetables. Due to the higher chocolate liquor content in dark chocolate, dark chocolate has a higher antioxidant concentration than milk chocolate [4, 8]. In chocolate manufacturing, a knowledge of the nutritious value of the cacao bean and the chemical and physical property changes at each and every step of the process should be known. It is clear that chocolate has the possibility to provide nutritious benefits when consumed. However, the choices of additional ingredients added to the chocolate liquor should be examined to determine their positive or negative nutritious effect. Research in the chocolate industry needs to use this knowledge of nutritional content within cacao beans and the processes to optimize the nutritional content in all chocolate products. 4

5 Methodology Phase One This research project would consist of two phases. One phase would involve optimizing the nutrients in the chocolate liquor and the second phase would involve optimizing the nutrients in the final chocolate product with all ingredients added in. To optimize the nutrient content in the chocolate liquor, the roasting, winnowing and milling processes will be optimized. To determine the optimal conditions that provide the most nutrient density in the chocolate liquor, trials of varying temperature and time spent in each process will be completed. For the roasting process, direct roasting will be used, roasting the cacao beans still in the shells. Temperatures at five degree intervals between 125C and 175C will be used in the trials. The trials will run at 30, 35, 40, 45, 50, 55, and 60 minutes. Every combination of time and temperature will be run. For the winnowing process, a process that optimizes the chocolate nib recovery will be determined. Winnowing cracks the cacao bean, separating the nib, shell and germ. Cracking the beans too vigorously will result in formation of fine particles that can t be used in production because the winnower cannot differentiate between what is a shell particle and what is a nib particle. Research on this process will look at increasing and decreasing the air currents flowing through the winnower. Altering the air current in the winnower will change the effectiveness of the separation of nib from shell. Each sample from the roasting process will undergo the different air current speeds. The milling process utilizes the heat of grinding the cocoa nibs to release the cocoa butter within the cocoa nibs, coating and suspending the solid cocoa particles. This process creates a liquid solution, chocolate liquor. All the samples in this project will undergo the same milling process After each process, the flavonoid content will be measured using the Total Phenolic Assay and the Folin Ciocalteu method. This method uses a UV-vis Spectrophotometer to measure the reflection/transmission properties of a material. A calibration curve will be determined using a galic reagent at varying percentages before the desired chocolate solution/mixture is analyzed. Phase Two The second phase of the research project will look at optimizing the flavonoid content in the final milk chocolate product. The main research will be on increasing the chocolate liquor content in milk chocolate to increase the flavonoid content, while maintaining the milk chocolate taste. In addition to chocolate liquor content, the amount of ingredients and types of ingredients will be analyzed to determine the optimal flavonoid content with the same milk chocolate taste. To be considered milk chocolate by the FDA, there must be a minimum of 10% chocolate liquor. The higher the content of chocolate liquor, the bitterer the chocolate will taste, creating a product 5

6 more similar to dark chocolate than milk chocolate. This phase of the research project will look at increasing the percentage of chocolate liquor in milk chocolate, and the amount and type of sugar and milk that would be needed to maintain the sweet taste of milk chocolate. Chocolate percentages of 10, 15, 20, 25, 30, 35, and 40 will be used, with the correct proportions of milk and sugar for each respective trial. Confectioner s sugar will be used as the main sugar ingredient, however, this phase will provide trials on the effects of a sugar substitute. For the milk, a skim milk, 1% fat, and 2% fat milks will be used in the liquid form. Dried milk will also be used for this research project. Cocoa butter will also be used to in the phase, adding the necessary fat to reach a milk chocolate flavor. The cocoa butter amount per trial will depend on the type and amount of milk used, adding the necessary amount of fat to reach the correct viscosity of chocolate solution to continue in the production of the chocolate. The flavonoid content of each ingredient and chocolate liquor will be measured prior to the beginning of phase two trials. As stated above, the Total Phenolic Assay will be used to determine the flavonoid content. After the ingredients are added together to form the chocolate mixture, the flavonoid content will be measured. These trials will be done for each sample produced from Phase One. While this project will not look at the effects of the tempering or conching of the chocolate, the chocolate samples will undergo these processes under uniform conditions. After the chocolate solutions become hard chocolate, the taste and flavonoid content will be measured at this point also. Schedule of Work Phase One Week 1 Basic Material Research Understanding of all the equipment and proper usage Week 2 Measurement of initial flavonoid content in all cacao bean samples Week 3 4 Roasting Process Trials Week 5 6 Winnowing Process Trials Week 7 8 Milling Process Trials Phase Two Week 9 Measurement of initial flavonoid content in all ingredient samples Sugars, Milks, Cocoa Butters Week Run the numerous Ingredient Combinations Week 14 Measure the final flavonoid content of all Phase Two Trials After cooling and tempering, run taste tests to determine quality of chocolate compared to a standard milk chocolate sample Week 15 Determine the optimal process that increases the nutrient density of flavonoids in milk chocolate, while maintaining taste 6

7 Budget The primary cost of this research project is the actual chocolate manufacturing process equipment. The best outcome would be to complete this research project in a facility set up to run these types of research projects. The other costs of this project are in the necessary materials to run a chocolate manufacturing process along with the cost of lab equipment. The lab equipment and testing equipment include test tubes, flasks, spectrophotometers, mechanical stirrers, etc. Supplies Cost ($) Raw Cacao Beans 1500 Other Raw Ingredients (Sugar, Milk, Cocoa Butter) 400 Lab Processing Equipment 3,000 Testing Equipment 1,000 Documentation Equipment 1,500 Chocolate Manufacturing Process Equipment 25,000 Total Estimated Cost 32,400 Qualifications of Researcher This research project will be performed by Julie Henderson, a junior chemical engineering major with a specialty in biochemical engineering and a minor in nutrition. In her time as an undergraduate at Case Western Reserve University, Julie has taken multiple courses relevant to this research, including Process Control, Thermodynamics in Chemical Systems, Separation Processes, Biochemistry, and Nutrition. With a GPA of 3.64, Julie has shown a good work ethic and dedication to her studies, giving her a highly adequate background in the necessary coursework to complete this research project. Anticipated Involvement of the Faculty Member The two faculty members chosen to assist with the facilitating and advising of this project will have a hands off role. While the actual research will be independent, the faculty members will be there to answer any questions or to offer advice as to overcome a particular problem or improve the research process. They will be used as advisors to the research, each providing their own insight into the respective parts of the project. Professor Heidi Martin s expertise in process control will be useful during phase one of the research project. Martin will be able to guide the researcher with the three separate processes involved in the first phase. Professor Hope Barkoukis expertise in nutrition and food processes will be useful in the second phase of this research project. Barkoukis will be able to help the researcher understand the meanings of the results throughout and at the end of the project. 7

8 Bibliography 1. Attaie, H., Breitschuh, B., Braun, P., & Windhab, E. J. (2003). The functionality of milk powder and its relationship to chocolate mass processing, in particular the effect of milk powder manufacturing and composition of the physical properties of chocolate masses. International Journal of Food Science and Technology, 38, Engler, M. B., & Engler, M. M. (2004). The vasculoprotective effects of flavonoid-rich cocoa and chocolate. Nutrition Research, 24, Fryer, P., & Bakalis, S. (2011). Engineering taste: The high-tech challenges in making chocolate. Focus on Heat Transfer, Hurst, W. J., Glinksi, J. A., Miller, K. B., Apgar, J., Davey, M. H., & Stuart, D. A. (2008). Survey of trans-resveratrol and trans-piceid content of cocoa-containing and chocolate products. Journal of Agricultural and Food Chemistry, 56, Keijbets, E. L., Chen, J., & Veira, J. (2010). Chocolate demoulding and effects of processing conditions. Journal of Food Engineering, 98, McShea, A., Ramiro-Puig, E., Munro, S. B., Casadesus, G., Castell, M., & Smith, M. A. Chocolate benefit and preservation of flavonols in dark chocolate manufacturing. Nutritional Reviews,66(11), Tannenbaum, G. (2004). Chocolate: A marvelous natural product of chemistry. Journal of Chemical Education, 81(8), Vinson, J. A., Proch, J., & Zubik, L. (1999). Phenol antioxidant quantity and quality in foods: Cocoa, dark chocolate, and milk chocolate. Journal of Agricultural and Food Chemistry, 47(12),