Passang Lhamo | ALES Graduate Seminar

A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Course-Based Seminar by Passang Lhamo. This seminar is open to the general public to attend.

Thesis Topic: Rheological analysis of heat-induced gels from egg white and pea protein isolates with and without polysaccharides

MSc with Dr. Jianping Wu.

Seminar Abstract:

The increase in the popularity and consumption of plant-based food is a growing trend in the food industry. In this context, plant-based eggs have been developed as a substitute for traditional table eggs. Plant-based eggs are free from egg allergens and cholesterol, while also demonstrating a reduced environmental impact. However, plant-based eggs available on the market exhibit low protein content, poor texture along a lack of elastic mouthfeel. Pea protein isolate (PPI), due to its sustainable nature, balanced amino acid profile and low allergenicity has the potential to be utilized as an ingredient in the plant-based egg. This study aims to prepare a gel using PPI with a concentration below its minimum gelling concentration. Heat-induced gelation was performed to prepare a gel from PPI with and without polysaccharides such as kappa-carrageenan (κ-C), waxy corn starch (WCS) and potato starch (PS). Proximate analysis, inversion assay and rheological study were performed. The protein content of the PPI was 80±0.61%. The minimum gelling concentration of pea protein isolate at 95°C for 30 minutes was 15. In comparison, the minimum gelling concentration of 12.5% PPI was made possible with the addition of κ-C, WCS and PS at a level of 0.2%, 3.5% and 3%, respectively. Egg white gel was prepared at 95°C for 30 minutes as a control. The storage modulus G’ of egg white gel was higher compared to loss modulus G” which indicates the elasticity of egg white gel. The value of tan δ was less than 1 which indicates solid-like behavior in the egg white gel system. The 20% PPI exhibited the highest storage modulus G’ and resulted in the formation of a firm gel. The storage modulus G’ of all the samples of PPI with κ-C was higher than loss modulus G” indicating elastic behavior in the system. The 12.5% PPI with 0.5% κ-C had the lowest tan δ. The 12.5% PPI with 3.5% WCS had the highest storage modulus G’. In addition, tan δ was lowest for 12.5% PPI mixed with 3.5% WCS. The 12.5% PPI mixed with 3% PS had the highest storage modulus G’. Tan δ of all the samples containing PPI and PS were below 1. Overall, 12.5% pea protein isolate mixed with 0.2% κ-C was closest to the rheological properties of egg white based on a time-sweep. Thus, the mixture containing 12.5% PPI and 0.2% κ-C can be further analyzed to understand the mechanism involved in gel formation and textural attributes.