Book Description

Consumer acceptability, or “liking,” is a complex consumer reaction to food which impacts food-derived enjoyment, purchasing behavior, and satiety, and is thus of interest to the food industry as well as consumers and researchers. While numerous factors impact acceptability, food flavor plays an outsize role in determining if a food is liked or disliked. Traditional methods of analyzing flavor identify individual compounds in isolation and out of context, primarily due to instrumental limitations. These methods have limited capability to understand acceptability, itself more a consumer reaction to the holistic experience provided by food than to individual sensory attributes or impact compounds. Chemical profiling and multivariate modeling of metabolites to find compounds predictive of effects, termed “metabolomics,” has recently been applied to the study of flavor. The resulting technique, termed flavoromics, offers the unprecedented ability to directly tie the underlying chemistry of a food to acceptability and other complex sensory percepts through statistical modeling. Compounds predicted to be important to acceptability can be recombined with the original food system and tasted to determine if they drive liking or are merely correlated, providing crucial confirmation for further application and use of findings. While showing great potential for compound discovery, flavoromics remains an emerging technique. Within this dissertation, flavoromics was used across two studies to understand chemical drivers of liking in fruit spreads. Sugar-free fruit spreads have been observed to universally present atypical flavor defects not seen in traditional products and are less-liked than full-sugar spreads. To understand chemical drivers of positively perceived flavors in traditional spreads, flavoromics was used to find universal differences between sugar-free and traditional jams across eight fruit varieties through class-based modeling to remove the impact of fruit variety. Four non-volatile compounds predictive of traditional spreads as compared to sugar-free spreads, regardless of fruit, were identified and tasted. Two compounds, including one which had not previously been described for flavor activity, were revealed to have sensory impact which made sugar-free spreads taste more-similar to traditional spreads, although further sensory validation is needed. This study showed the ability of flavoromics to relate chemistry to flavor-relevant class-based differences regardless of orthogonal variations such as fruit type, and to uncover flavor-active compounds linked to an effect. This study will provide molecular targets to the jam industry for use in producing better-liked sugar-free products, helping dieting consumers achieve sugar-reduction goals without sacrificing flavor enjoyment. The second study focused on linking chemistry directly to consumer ratings of acceptability in strawberry preserves. Fifteen unique strawberry preserves were manufactured using an identical process. Preserves were profiled using untargeted GC/MS and LC/MS to capture flavor-relevant chemical information and were rated by a consumer acceptability panel. Collected chemical data was correlated to acceptability to uncover compounds directly related to liking. Four non-volatile and nine volatile compounds were identified as highly-correlated to acceptability, including two novel non-volatiles and one novel flavor active volatile. Compounds were recombined with spreads and rated by a consumer preference panel, revealing a bimodal distribution of preference which partially broke down by gender. It was found that women significantly preferred jams spiked with acceptability-linked non-volatile compounds over control jams, while men did not display a preference. Although more work is required to investigate causes of preference distributions, this work successfully showed the capability of flavoromics to identify compounds which drive liking in foods. This second study serves to provide crop breeders and jam producers with molecular targets for marker-assisted crop breeding, raw ingredient selection, and process optimization. Together, the two studies discussed in this dissertation present a proof-of-concept for the use of flavoromics to understand acceptability and open the door to greater use of the technique towards understanding drivers of complex sensory percepts in foods.