UVM Theses and Dissertations
Format:
Print
Author:
Wang, Guorong
Dept./Program:
Animal, Nutrition and Food Sciences Program
Year:
2014
Degree:
Ph. D.
Abstract:
Whey protein isolate (WPI) is produced from a by product of cheese making - liquid whey. Current commercial available office glue products (both liquid glue and glue stick) are widely used in households, offices and schools, but those products are usually made from undegradable synthetic polymers mostly from petroleum products, and may either contain compounds or not be environmentally safe. The objectives of this study were to develop a novel environmentally friendly office glue using natural whey protein as a major ingredient. Whey protein is mainly composed of compact globular proteins (50% [Beta]-lactoglobulin, 20% [alpha]-lactabumin, and the resting 30% are bovine serum albumin, immunoglobulin, lactoferrin, lysozyme and lactoperoxidase) with low molecular weights (about 80% of the components are less than 20 kDa). The globular structure can be unfolded to linear polymer which resembles to synthetic adhesive polymers under thermo-treatment, and intermolecular bonds can be formed via disulfide-thiol interchange to increase the molecular length.
However, for whey protein based adhesive, it is either too watery with low bonding strength at low concentration, or very inclined to gel under thermo treatment or during storage at high concentration. In this study, a safe synthetic polymer, polyvinylpyrrolidone (PVP), and a natural safe material, sucrose, were used to improve the functionality and consistency of polymerized whey proteins (PWP) based glue. Two types of liquid paper glue based on PWP/ polyvinylpyrrolidone (PVP) and PWP/sucrose, and one type of glue stick based on PWP/PVP/sucrose were formulated and analyzed in comparison with commercial controls.
Results showed that the three types ofprototypes (PWP/PVP liquid glue, PWP/sucrose liquid glue, and PWP/PVP/sucrose glue stick) exhibited desirable bonding strength and stable storage property, and possessed faster or comparable setting property to the commercial controls. Neither significant changes of bonding strength, viscosity or appearance, nor growth of microbes were observed during storage at 23°C or 40°C for 12 months in any of the three types of prototypes with addition of a preservative. Both PVP and sucrose increased the bonding strength, prevented whey protein from gelation during thermo treatment (up to 90°C for 30 min) and stabilized the viscosity of the liquid glue during storage (23°C or 40°C for 12 months). In glue stick, both PVP and sucrose improved the hardness of the gel stick and acted as moisturizer to prevent the glue gel from drying during storage.
In conclusion, with addition ofPVP and/or sucrose, polymerized whey protein can be used as a novel natural and safe polymer to formulate both liquid glue and glue stick products with comparable quality with current commercial products.
However, for whey protein based adhesive, it is either too watery with low bonding strength at low concentration, or very inclined to gel under thermo treatment or during storage at high concentration. In this study, a safe synthetic polymer, polyvinylpyrrolidone (PVP), and a natural safe material, sucrose, were used to improve the functionality and consistency of polymerized whey proteins (PWP) based glue. Two types of liquid paper glue based on PWP/ polyvinylpyrrolidone (PVP) and PWP/sucrose, and one type of glue stick based on PWP/PVP/sucrose were formulated and analyzed in comparison with commercial controls.
Results showed that the three types ofprototypes (PWP/PVP liquid glue, PWP/sucrose liquid glue, and PWP/PVP/sucrose glue stick) exhibited desirable bonding strength and stable storage property, and possessed faster or comparable setting property to the commercial controls. Neither significant changes of bonding strength, viscosity or appearance, nor growth of microbes were observed during storage at 23°C or 40°C for 12 months in any of the three types of prototypes with addition of a preservative. Both PVP and sucrose increased the bonding strength, prevented whey protein from gelation during thermo treatment (up to 90°C for 30 min) and stabilized the viscosity of the liquid glue during storage (23°C or 40°C for 12 months). In glue stick, both PVP and sucrose improved the hardness of the gel stick and acted as moisturizer to prevent the glue gel from drying during storage.
In conclusion, with addition ofPVP and/or sucrose, polymerized whey protein can be used as a novel natural and safe polymer to formulate both liquid glue and glue stick products with comparable quality with current commercial products.