PhD Defence - Kristin Mattice "Characterizations of Zein: Evaluating Functionality and Potential Uses In Food Structuring"
Date and Time
Location
Food Science building - room 239 (Pearson Room)
Details
Final Examination for the Degree of PhD Food Science - Kristin Mattice
Examining Committee
Dr. Lisa Duizer, Chair
Dr. Alejandro Marangoni, Advisor
Dr. Loong-Tak Lim, Advisory Committee Member
Dr. Douglas Goff, Department Member
Dr. Rotimi Aluko, University of Manitoba, External Examiner (Skype)
TITLE: CHARACTERIZATIONS OF ZEIN: EVALUATING FUNCTIONALITY AND POTENTIAL USES IN FOOD STRUCTURING
ABSTRACT: This thesis encompasses a thorough investigation in the potential use of zein networks as a structuring ingredient in plant-based alternatives. The popularity of plant-based products is continually increasing; however, the majority of plant-based products lack important properties that are characteristic to the conventional products. Attempts to improve these products focused on the use of zein, a protein that had not been studied extensively as a food ingredient previously. For the purpose of structuring whole muscle meat analogues, three techniques were developed to produce fibrous material from zein, either as fibrous networks or individual protein fibres. These techniques are: electrospinning, antisolvent precipitation of zein from ethanol using water and mechanical elongation of self-assembled zein networks. It was determined that the zein fibres produced were able to contribute a chicken-like texture to soy protein isolate gels when fibres were of uniform size and orientation. Despite this promising result, in depth investigation into the rheology of zein networks revealed inherently brittle behaviour, particularly when compared to the ductility of chicken muscle tissue. Efforts to reduce the brittleness of zein networks through enzymatic crosslinking with microbial transglutaminase proved unsuccessful and instead caused the brittleness of the network to increase even further. As an alternate technique, an increase in ductility was observed when zein networks were formed through antisolvent precipitation from acetic acid. Even further increases in ductility were material was achieved through antisolvent precipitation from ethanol. This research has therefore provided an increased understanding of the potential structural and rheological contribution of zein in food products. In addition, it provides the basis for the development and production of functional zein-structured, plant-based products.
TITLE: CHARACTERIZATIONS OF ZEIN: EVALUATING FUNCTIONALITY AND POTENTIAL USES IN FOOD STRUCTURING
ABSTRACT: This thesis encompasses a thorough investigation in the potential use of zein networks as a structuring ingredient in plant-based alternatives. The popularity of plant-based products is continually increasing; however, the majority of plant-based products lack important properties that are characteristic to the conventional products. Attempts to improve these products focused on the use of zein, a protein that had not been studied extensively as a food ingredient previously. For the purpose of structuring whole muscle meat analogues, three techniques were developed to produce fibrous material from zein, either as fibrous networks or individual protein fibres. These techniques are: electrospinning, antisolvent precipitation of zein from ethanol using water and mechanical elongation of self-assembled zein networks. It was determined that the zein fibres produced were able to contribute a chicken-like texture to soy protein isolate gels when fibres were of uniform size and orientation. Despite this promising result, in depth investigation into the rheology of zein networks revealed inherently brittle behaviour, particularly when compared to the ductility of chicken muscle tissue. Efforts to reduce the brittleness of zein networks through enzymatic crosslinking with microbial transglutaminase proved unsuccessful and instead caused the brittleness of the network to increase even further. As an alternate technique, an increase in ductility was observed when zein networks were formed through antisolvent precipitation from acetic acid. Even further increases in ductility were material was achieved through antisolvent precipitation from ethanol. This research has therefore provided an increased understanding of the potential structural and rheological contribution of zein in food products. In addition, it provides the basis for the development and production of functional zein-structured, plant-based products.