Bloodmeal Hydrolysate In Novatein Thermoplastic Protein
Ahuja, G. (2014). Bloodmeal Hydrolysate In Novatein Thermoplastic Protein (Thesis, Master of Engineering (ME)). University of Waikato, Hamilton, New Zealand. Retrieved from http://hdl.handle.net/10289/9642
Permanent Research Commons link: http://hdl.handle.net/10289/9642
Novatein Thermoplastic (NTP) is a bloodmeal based plastic developed by the University of Waikato by mixing bloodmeal with water, additives and tri-ethylene glycol (TEG - a plasticiser and petroleum based product) so it can be extruded and injection moulded. The aim of this research was to produce a bloodmeal hydrolysate that could be used in NTP as a substitute for TEG, and also used to treat sodium bentonite clay to improve its properties as a filler in NTP. Bloodmeal was hydrolysed with pepsin and alcalase to determine the reaction rate, degree of hydrolysis and optimum conditions. Bloodmeal could be readily hydrolysed giving up to 80% hydrolysis yield with 25-40% degree of hydrolysis, with average peptide molecular weight ranging between 2-12 kDa for alcalase, and 20-25% degree of hydrolysis and average molecular weights of 20-80 kDa for pepsin. Large scale hydrolysis with alcalase, trypsin and then pepsin gave 80% hydrolysis yield, and peptide average molecular weights at 8.9 kDa for alcalase, to 5.5 for trypsin. Adsorption of hydrolysate on to sodium bentonite gave 127 mg/g clay adsorption for alcalase, but was low for trypsin, and no adsorption occurred for pepsin hydrolysate. Specific mechanical energy required to extrude NTP increased with increasing hydrolysate content but only slightly increased with clay content, but in both cases increased with extent of hydrolysis, i.e. trypsin hydrolysate gave greater SME than alcalase, and pepsin hydrolysate gave greater SME than trypsin, which could be due to the increasing salt content in the hydrolysate. Tensile strength, secant modulus, crystallinity, thermostability and glass transition temperature decreased with increasing hydrolysate content in NTP, likely due to the shorter average protein chain length, indicative of some plasticisation. Glass transition temperature did not change for NTP with alcalase hydrolysate. Toughness, strain at break, and impact strength were low indicating a very brittle material. Highly variable results were obtained for the NTP with treated and untreated clay as a filler, but generally gave lower mechanical properties than conventional NTP. Alcalase treated clay was particularly detrimental on NTP composite strain at break and toughness. Thermostability of the composites increased within the 450-600oC region with increasing clay concentration for all treated clays, but showed a much more rapid decrease in mass loss.
University of Waikato
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