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 Lily Lincoln.
ABSTRACT
Recently, there has been an increased consumer interest in plant-based protein products due to their ability to provide a sustainable, ethical, and “healthier” alternative to animal-based products. However, significant “beany” and “grassy” off-flavors associated with protein-rich plant ingredients have hindered their widespread acceptance. These off-flavors are products of lipid oxidation and Maillard reactions that can occur during processing and storage. Polyphenols have emerged as a potential solution to disrupt these reactions due to their protein-binding capabilities and inherent antioxidant capacity. We hypothesized that polyphenols with larger structures including more hydroxyl groups will more effectively reduce off-flavors due to their increased ability to bind with proteins. Pea (10% w/v) and soy (8% w/v) protein solutions were treated with 0.02% w/w catechin, green tea extract (GTE), grape seed extract (GSE), or tannic acid (TA). Quantification of free polyphenols showed that at least 64% of all tested polyphenols were bound to proteins (catechin < TA < GSE). Catechin, TA, and GSE significantly reduced melanoidin production by 39%, 43%, & 48%, respectively. Because GSE had the highest amount of polyphenol-bound protein, preventing those amine groups from reacting with reducing sugars, it was able to inhibit Maillard reaction products most effectively. Polyphenol addition significantly reduced volatile Maillard reaction and lipid oxidation products including hexanal, furan, benzaldehyde, hexanol, and heptanone production. Results indicate that addition of polyphenols disrupts flavor degradation pathways and production of their primary and secondary products. Findings from this study will be used to find solutions to reduce undesirable oxidative and Maillard reaction products found in lipid and protein food systems.
