Time: 12:05–12:55
Location: Room 205, Babcock Hall
Coffee / tea will be served starting ~11:45 outside room 205
This seminar will be presented by Cameron Wicks.
Polyphenol-Mediated Protein and Fat Structure Development in a Frozen Dessert Model
Polyphenols are known to influence the health benefits and sensory attributes of ice cream. Research suggests that increasing the phenolic content can result in a “no melt” ice cream that maintains its shape at ambient temperature. However, there is little understanding of why this phenomenon occurs. This study aims to examine the effects of polyphenols on the structure and melting characteristics of ice cream. Certain polyphenols affect both protein and fat, leading to a structure that prevents frozen desserts from collapsing. In this research, tannic acid (TA) was added to dairy cream to create a model system with protein, fat, and polyphenols. As the TA% increased, the complex viscosity of the samples also increased. Microscope images and particle size distributions confirmed the presence of fat globule clusters in the TA-cream samples. Chemical treatments showed that protein-mediated fat aggregation may be the mechanism behind the clustering.
Tannic acid was added to ice cream to further investigate the role of these fat clusters as a major structural component and their impact on melting behavior. Three ice cream formulations (base, high protein, and high fat) were tested with different TA concentrations. The study revealed that TA decreased the melting rate and enhanced melting properties. This was supported by the complex viscosity and thixotropic behavior, which indicated the structural basis for these properties. The high-fat formula generally had better melting characteristics than the high-protein formula, highlighting the importance of fat in the system’s success. The study findings also suggested that TA could effectively limit ice crystal growth in temperature-abused ice cream samples, indicating its potential to act as a substitute for conventional stabilizers. This prompted further research to determine if high phenolic extracts (green tea and grapeseed) could serve as stabilizers. The ice cream samples containing high phenolic extracts exhibited satisfactory shape retention, reduced melting rate, and limited ice crystal growth. However, the high cost of these extracts necessitated the exploration of alternative fruit sources to determine if they could provide similar melting characteristics. While various standardized fruit extracts, freeze-dried powders, and juice concentrates showed improved melting rates compared to the control, their rates were still 10% higher than the high phenolic extracts, and they lacked the same level of shape retention. This study successfully developed an ice cream with enhanced shape retention and identified the mechanism and parameters for an optimal product.
