UVM Theses and Dissertations
Format:
Print
Author:
Zhou, Lihua
Dept./Program:
Nutritional and Food Sciences
Year:
2010
Degree:
MS
Abstract:
Glue stick products for bonding paper on the market may contain toxic volatile organic compounds (VQCs). The production of whey, a by-product of cheese making, is continuing to increase. It is urgent to find new applications for whey products such as whey proteins. In this study, safe glue sticks containing whey proteins were developed. A five-factor, three-level orthogonal experiment was designed to optimize the formulation with the binders including whey protein isolate (WPI), polyvinyl alcohol (PVA) and polyvinylacetate (PVAC), the hardener, sodium stearate and the moisturizer, propylene glycol (PO) as variables. As the major index for evaluating glue stick products, bonding strength of different glue samples were measured.
Results showed that WPI, PVA, PVAC and sodium stearate all had significant effects on bonding strength (p<0.05). The bonding strength was the highest (59.25 N) for the formulation with 300 g WPI (10%, w/w) solution, 400 g PYA solution (w/w, 20%), 300 g PVAC and 70 g of sodium stearate and PO. Different production methods also had significant impact on bonding strength (p<0.05). The bonding strength of the prototype prepared using the high speed blending technique was as high as that of the commercial glue stick (p<0.05). Experiments were also conducted to investigate the effects of nano calcium carbonate on bonding strength, however, the effect was not significant (p>0.05). The glue stick prototype was free of microbial growth during storage period of 6 months. However bonding strength of the prototypes dropped significantly during storage life (P<0.05). Further research needs to be done to m~intain the products' shelf life stability.
Results showed that WPI, PVA, PVAC and sodium stearate all had significant effects on bonding strength (p<0.05). The bonding strength was the highest (59.25 N) for the formulation with 300 g WPI (10%, w/w) solution, 400 g PYA solution (w/w, 20%), 300 g PVAC and 70 g of sodium stearate and PO. Different production methods also had significant impact on bonding strength (p<0.05). The bonding strength of the prototype prepared using the high speed blending technique was as high as that of the commercial glue stick (p<0.05). Experiments were also conducted to investigate the effects of nano calcium carbonate on bonding strength, however, the effect was not significant (p>0.05). The glue stick prototype was free of microbial growth during storage period of 6 months. However bonding strength of the prototypes dropped significantly during storage life (P<0.05). Further research needs to be done to m~intain the products' shelf life stability.