Analysis of Vanilla Compounds in Vanilla Extracts and Model Vanilla Ice Cream Mixes Using Novel Technology Thesis Presented in Partial Fulfillment of the Requirements for the Degree Masters of Science in the Graduate School of The Ohio State University By Michael Dennis Sharp, B.S. Graduate Program in Food Science and Technology The Ohio State University 2009 Thesis Committee: W James Harper, Advisor Mike Mangino David Min 1 Copyright by Michael Dennis Sharp 2009 Abstract Vanilla is an important flavor for many foods. Vanilla beans have been shown to contain over 200 compounds, which can vary in concentration depending on the region where the beans are harvested. Several compounds including vanillin, p- hydroxybenzaldehyde, guaiacol, and anise alcohol have been found to be important for the aroma profile of vanilla. Because of the complexity of the vanilla aroma profile there are many gaps in the current understanding of how vanilla compounds are volatilized in food systems. Several novel analytical technologies are under investigation for their ability to aid in analyzing compounds in vanilla extracts and in model ice cream mixes. Although several methods are currently available, a need exists for a more rapid and sensitive method to analyze the concentration of important compounds in vanilla beans and extracts. Selected ion flow tube mass spectroscopy (SIFT-MS) and fourier transform infrared (FTIR) spectroscopy are two methods that have potential for rapid discrimination and characterization of vanilla extracts. Vanilla extracts made with beans from different countries of origin including Uganda, Indonesia, Papua New Guinea, Madagascar, and India were analyzed using both methods of analysis. Pirouette statistical software, a multivariate data analysis tool, was utilized to determine the differences between samples. Differentiation between samples was observed for all extracts, with Papua New Guinea and Indonesian samples differing the most from other ii samples. The top 5 compounds found to be most responsible, based on discriminating power, for the differentiation between samples were vanillin, anise alcohol, methylguaiacol, p-hydroxybenzaldehyde, and p-cresol. The top wavenumbers found to be most responsible, based on discriminating power, for the differentiation between samples were 1523, 1573, 1516, and 1292 cm-1. These wavenumbers have been associated with vanillin and vanillin derivatives in previous studies. Both methods have shown to be quick and reliable methods for analyzing vanilla extracts which could be utilized as a quality assurance tool in the fragrance, flavoring, and food industries. Flavor-food interactions have been shown to be important to the overall flavor profile of many foods including ice cream. Vanilla flavor, being the top flavor of ice cream, has been shown to be reduced in intensity due to protein and fat in ice cream. A research gap exists in understanding how vanilla compounds besides vanillin, the most abundant vanilla compound, and other ingredients besides protein and oil interact. A 3x3x2x2x2 full factorial design with oil, protein, sugar, stabilizer, and corn syrup as factors was conducted. Each mixture of ice cream ingredients was analyzed for headspace concentration of vanilla compounds using a selected ion flow tube mass spectrometry (SIFT-MS) technique. Although the most amount of compounds were statistically significantly effected by protein and oil, other ingredient and interactions between ingredients effected the headspace concentration of a variety of vanilla compounds. By changing the formulation of an ice cream mix, the vanilla flavor profile is clearly altered. iii Acknowledgements This work would not have been possible without the tremendous help, advise, encouragement, and trust from many kind individuals. Firstly my advisor Dr. Harper for all of his support and expertise as well as the freedom he gave me to explore my interests. I would also like to thank all of the research associates and lab mates for advise and help working through problems. I couldn’t have done the research I did without the help of Virginia Dare for providing all the samples I needed, or the many knowledgeable and skilled people at Syft technologies. I mostly would like to thank my wife and daughter for being so supportive, trusting, sacrificing and willing to allow me this opportunity. iv Vita 2001………………………………..…………………………….West Jordan High School 2006-2008……………….…………………….………Food Scientist, Casper’s Ice Cream 2007………………………….…..B.S. Food Science and Nutrition, Utah State University 2008-2009……………………Graduate Research Assistant, Department of Food Science and Technology, The Ohio State University 2009-Present………………………………………..Product Scientist, Dreyer’s Ice Cream Publications Sharp MD, McMahon DJ, Broadbent J. Comparative evaluation of yogurt and low-fat Cheddar cheese as delivery media for probiotic Lactobacillus casei. J Food Sci 73(7):M375-M377 Field of Study Major Field: Food Science and Technology v Table of Contents Abstract……………………………………………………………………………..……..ii Acknowledgements……………………………………………………………………….iv Vita………………………………………………………………………………………...v Chapter 1: Literature Review……………………………………………………………...1 Chapter 2: Rapid Discrimination and Characterization of Vanilla Extracts Made From Countries of Different Origin by FTIR-ATR and SIFT-MS………………………….…49 Chapter 3: Flavor-Ingredient Interactions Between Vanilla Compounds and a model Ice Cream Mix……………………………………………………………………………….80 Appendix A: Vanilla Compound Concentrations In Vanillas Of Unique Countries Of Origin………………………………………………………………….. …………...…109 Appendix B: Estimates and P-Values For Measured Parameters For All Ingredients And Ingredient Interactions………………………………………………………………….115 References……………………………………………………………………………....153 vi CHAPTER 1 Literature Review 1.1 Vanilla 1.1.1 Vanilla Overview Although vanilla is the second most expensive spice, next to saffron, it is still the most widely used (Ranadive 2005). Vanilla has a very versatile flavor that is acceptable at almost any concentration (Korthou and Verpoorte 2007). Because vanilla is such a versatile and well accepted flavoring it is used readily in the food, beverage, cosmetic, and tobacco industries (Korthou and Verpoorte 2007). In the United States alone 1350 metric tons of cured vanilla beans are imported yearly and over 2100 metric tons are imported globally per year (Ranadive 2005). Natural vanilla flavorings are extracted from the plant genus Vanilla (Rao and Ravishanker 2000). Two species from this genus have been used and approved in most countries to create vanilla flavoring including Vanilla planifolia and Vanilla tahitensus, however Vanillus planifolia is more widely used because of its pod quality and yield (Sinha and others 2008). V. planifolia was originally cultivated in Mexico by the Aztecs (Sinha and others 2008). After the arrival of the Spaniards in Mexico and the discovery of artificial pollination techniques, V. planifolia is now cultivated in many tropical climates that fall between 25˚ above and below the equator (Havkin-Frenkel and Dorn 1 1997). Today the principle vanilla cultivating country is Madagascar which exports 1000-1200 tons of cured vanilla beans per year (Ranadive 2005). Other countries that export a significant amount of vanilla include Indonesia, the Comoro Islands, Uganda, India, Tonga, Mexico and Tahiti (Ranadive 2005). Vanilla planifolia is grown on large looping vine fields with about 2000 vines per hectare (Ranadive 2005). Vanilla thrives in warm moist tropical climates, but also needs plenty of shade and support. Vanilla also has shallow roots that require well drained soils (Ranadive 2005). At about 8 to 9 months post pollination, Vanilla beans are harvested. At the time of harvest however, green vanilla beans are flavorless and only contain glucosides of flavor compounds (Havkin-Frenkel and Belanger 2007). Vanilla’s characteristic flavor is developed during a process called curing as glucosides are released. Curing is the process in which the vanilla aroma develops in the pods or beans. This process for aroma development is carried out in dried vanilla beans and allows chemical and enzymatic reactions to occur (Dignum and others 2001). Although most vanilla cultivating countries have developed their own curing process, all processes generally consist of four steps: scalding, sweating, drying and conditioning (Dignum and others 2001). During these curing processes glycosides are hydrolyzed, and other compounds undergo oxidation or polymerization (Havkin-Frenkel and others 2005). Although cured vanilla pods themselves are sometimes used for flavoring, it is much more common that vanilla be used for flavoring as an extract. Vanilla extracts are prepared by either percolating cured beans with a water and ethyl alcohol, or by 2 macerating whole beans and then circulating ethanol over the pods under vacuum (Sinha and Others 2008). The latter method is able to increase the concentration or “fold” of the extract. Each fold of a vanilla extract is defined as 13.35 oz of extractable material per gallon of solvent (CFR 169.3). The Code of Federal Regulations (169.175) further defines a vanilla extract as having at least 35% ethanol, and contains one or more of the following ingredients: Glycerin, Propylene Glycol, Sugar, Dextrose, or Corn Syrup. Vanilla flavoring is defined as an extract that meets the same requirements as vanilla extract, but does not contain at least 35% ethanol (CFR 169.177). 1.1.2 Vanilla Flavor Compounds Over 200 compounds have