title: Oxidative Decolouring of Bloodmeal Using Peracetic Acid

authors: Hicks, Talia

subjects: Bloodmeal

abstract: Bloodmeal is an ancillary product of the agricultural industry, containing 80 – 100 % protein, and has been used to create a bio-based plastic called Novatein Thermoplastic Protein®, with a proprietary blend of sodium sulfite, sodium dodecyl sulfate (SDS), water and triethylene glycol (TEG). Recent investigation has shown that the colour and odour of bloodmeal based thermoplastic can be significantly improved through the pre-treatment of bloodmeal with equilibrium peracetic acid. The resulting decoloured bloodmeal (DBM) no longer relies on the addition of sodium sulfite to be processed in conventional thermoplastic equipment. The purpose of this study was to gain a comprehensive understanding of the role by which peracetic acid decolours bloodmeal and the consequences of oxidation on composition, physico-chemical properties, protein structure and interactions and final polymer mobility.
Oxidative decolouring of haem is straightforward when the haem is freely accessible or in the form of oxyhaemoglobin and most common oxidants lead to cleavage of the porphyrin ring, resulting in a loss of colour saturation. However, after extensive thermal treatment during manufacture, the haem present in bloodmeal has migrated to inaccessible hydrophobic regions of the protein aggregates or has been oxidised to the form of methaemoglobin. Literature revealed that methaemoglobin catalytically removes hydrogen peroxide, lowering decolouring efficacy. Thus, peracetic acid is required when haem is present in the form of methaemoglobin, as is found in bloodmeal. Further, it was confirmed that a minimum of 3% w/w peracetic acid, in a 3:1 ratio to bloodmeal is required to obtain adequate decolouring (> 70% whiteness based on the RGB colour space).
The role of each component in equilibrium peracetic acid was established; water and acetic acid resulted in protein swelling but were found unlikely to influence accessibility of the oxidants to the haem sites and both hydrogen peroxide and peracetic acid were consumed in oxidising reactions. Acidic conditions were found to reduce the consumption of hydrogen peroxide, possibly through the inhibition of hydroxyl radical formation, resulting in less effective decolouring. Acetic acid was observed to have a protective effect on protein recovery as well as the resulting iron content, molecular mass distribution and secondary structure of protein.
Due to the large excess of peracetic acid solution required to facilitate diffusion and subsequent decolouring, a significant quantity remains unreacted in the recovered wastewater. Unreacted peracetic acid was shown to have potential for recycling, although in its immediate state it was insufficient to decolour fresh bloodmeal.
The protein-rich decoloured bloodmeal recovered had undergone a change in secondary structure composition and was found to contain evidence of a diffusion front, consistent with the heterogeneous phase decolouring mechanism. Oxidation with peracetic acid was found to result in less β-sheet aggregation compared to hydrogen peroxide treatment, although all treatments resulted in an increase in the quantity of disordered structures. Oxidation was also found to result in a significantly lowered glass transition temperature and along with an increased enthalpy of relaxation, evidenced a large improvement in polymer chain mobility compared with untreated bloodmeal.
DBM was found to be comprised of 90 – 99% w/w protein (1 – 10% w/w salt), with a significantly higher protein solubility and a similar volume weighted molecular mass compared with untreated bloodmeal. Further, DBM was found to have a greater composition of charged and polar amino acids, along with a large reduction in lysine and small reduction in aromatic and heterocyclic amino acids. Additionally, cystine crosslinks which stabilise bloodmeal were found to be partially oxidised to cysteine sulfonate compounds and cysteic acid (cleavage of the disulfide bond). Such a reduction in the quantity of amino acids which are capable of forming covalent networks (lysine, tyrosine and cysteine) support prior evidence that DBM no longer requires sodium sulfite to produce a thermoplastic.
The influence of SDS and TEG on secondary structure and chain mobility at ambient and elevated temperatures were explored. It was found that heating DBM and DBM with SDS alone is incapable of providing sufficient energy to induce mobility and chain rearrangement. However, the addition of TEG was found to facilitate chain mobility, and beyond 55 oC significant changes to the secondary structure composition was observed, first through the formation of α-helices and finally through the aggregation of chains into β-sheets. Wide angle X-ray scattering confirmed that the changes in ordered structures composition were reversible in DBM which contained both SDS and TEG.
The ability of TEG to plasticise DBM was more thoroughly explored, and it was found that prior to heating TEG was localised into regions either plasticiser-rich or -poor, and this resulted in the presence of two glass transition temperatures. After heating, the TEG was more homogeneously distributed, which resulted in the presence of one broad glass transition region.

text: Oxidative Decolouring of Bloodmeal Using Peracetic Acid Bloodmeal is an ancillary product of the agricultural industry, containing 80 – 100 % protein, and has been used to create a bio-based plastic called Novatein Thermoplastic Protein®, with a proprietary blend of sodium sulfite, sodium dodecyl sulfate (SDS), water and triethylene glycol (TEG). Recent investigation has shown that the colour and odour of bloodmeal based thermoplastic can be significantly improved through the pre-treatment of bloodmeal with equilibrium peracetic acid. The resulting decoloured bloodmeal (DBM) no longer relies on the addition of sodium sulfite to be processed in conventional thermoplastic equipment. The purpose of this study was to gain a comprehensive understanding of the role by which peracetic acid decolours bloodmeal and the consequences of oxidation on composition, physico-chemical properties, protein structure and interactions and final polymer mobility.
Oxidative decolouring of haem is straightforward when the haem is freely accessible or in the form of oxyhaemoglobin and most common oxidants lead to cleavage of the porphyrin ring, resulting in a loss of colour saturation. However, after extensive thermal treatment during manufacture, the haem present in bloodmeal has migrated to inaccessible hydrophobic regions of the protein aggregates or has been oxidised to the form of methaemoglobin. Literature revealed that methaemoglobin catalytically removes hydrogen peroxide, lowering decolouring efficacy. Thus, peracetic acid is required when haem is present in the form of methaemoglobin, as is found in bloodmeal. Further, it was confirmed that a minimum of 3% w/w peracetic acid, in a 3:1 ratio to bloodmeal is required to obtain adequate decolouring (> 70% whiteness based on the RGB colour space).
The role of each component in equilibrium peracetic acid was established; water and acetic acid resulted in protein swelling but were found unlikely to influence accessibility of the oxidants to the haem sites and both hydrogen peroxide and peracetic acid were consumed in oxidising reactions. Acidic conditions were found to reduce the consumption of hydrogen peroxide, possibly through the inhibition of hydroxyl radical formation, resulting in less effective decolouring. Acetic acid was observed to have a protective effect on protein recovery as well as the resulting iron content, molecular mass distribution and secondary structure of protein.
Due to the large excess of peracetic acid solution required to facilitate diffusion and subsequent decolouring, a significant quantity remains unreacted in the recovered wastewater. Unreacted peracetic acid was shown to have potential for recycling, although in its immediate state it was insufficient to decolour fresh bloodmeal.
The protein-rich decoloured bloodmeal recovered had undergone a change in secondary structure composition and was found to contain evidence of a diffusion front, consistent with the heterogeneous phase decolouring mechanism. Oxidation with peracetic acid was found to result in less β-sheet aggregation compared to hydrogen peroxide treatment, although all treatments resulted in an increase in the quantity of disordered structures. Oxidation was also found to result in a significantly lowered glass transition temperature and along with an increased enthalpy of relaxation, evidenced a large improvement in polymer chain mobility compared with untreated bloodmeal.
DBM was found to be comprised of 90 – 99% w/w protein (1 – 10% w/w salt), with a significantly higher protein solubility and a similar volume weighted molecular mass compared with untreated bloodmeal. Further, DBM was found to have a greater composition of charged and polar amino acids, along with a large reduction in lysine and small reduction in aromatic and heterocyclic amino acids. Additionally, cystine crosslinks which stabilise bloodmeal were found to be partially oxidised to cysteine sulfonate compounds and cysteic acid (cleavage of the disulfide bond). Such a reduction in the quantity of amino acids which are capable of forming covalent networks (lysine, tyrosine and cysteine) support prior evidence that DBM no longer requires sodium sulfite to produce a thermoplastic.
The influence of SDS and TEG on secondary structure and chain mobility at ambient and elevated temperatures were explored. It was found that heating DBM and DBM with SDS alone is incapable of providing sufficient energy to induce mobility and chain rearrangement. However, the addition of TEG was found to facilitate chain mobility, and beyond 55 oC significant changes to the secondary structure composition was observed, first through the formation of α-helices and finally through the aggregation of chains into β-sheets. Wide angle X-ray scattering confirmed that the changes in ordered structures composition were reversible in DBM which contained both SDS and TEG.
The ability of TEG to plasticise DBM was more thoroughly explored, and it was found that prior to heating TEG was localised into regions either plasticiser-rich or -poor, and this resulted in the presence of two glass transition temperatures. After heating, the TEG was more homogeneously distributed, which resulted in the presence of one broad glass transition region.

year: 2015

title: Teachers' experiences in curriculum implementation: General curriculum, the arts, and health and physical education

authors: McGee, Clive

subjects: National School Sampling Study

abstract: This report is part of the National School Sampling Study, a Ministry of Education initiative to investigate how teachers work with the curriculum, 2002-2003. The first report in June 2001 outlined how teacher focus group discussions informed the development of national questionnaires. In April 2002 the research team reported on the first round of questionnaires: general curriculum; mathematics; technology; and Māori medium. A subsequent report in April 2003 outlined the results of questionnaires to investigate teachers' experiences in teaching from the New Zealand national curriculum documents in English, languages (Japanese, Spanish, Chinese, Korean and Samoan), science and social studies.
The major content of this report is the results of another general questionnaire and questionnaires on the arts and health and physical education. The report presents statistical data based upon frequencies and ratios, often organised into school type. Where appropriate, additional comments from `other' categories are presented. Questionnaires included open-ended questions, and results from these are from a sub-sample drawn up for each set of questionnaire responses.
The questionnaires were designed to allow teachers to self-report their curriculum experiences, particularly in using the documents that form a central part of New Zealand's national curriculum: The New Zealand Curriculum Framework (Ministry of Education, 1993), and the statements for the seven curriculum areas which were all relevant to this survey round. Some teachers focused upon the arts or the health and physical education curriculum statements; others on the curriculum generally. Teachers were asked about the documents themselves, professional development, assessment, reporting achievement, school curriculum organisation, the impact of various national curriculum policies, support and resources, and curriculum manageability. They were also encouraged to describe effective aspects of their teaching from the documents, and to reflect upon the impact upon student achievement.
The results show that national curriculum implementation is a complex matter. In general, teachers were reasonably positive about various aspects of their own teaching. Many reported increased confidence in planning, assessment and reporting. The curriculum documents were fairly positively regarded. A number of other factors contributed to teacher confidence such as professional development, resources, review of schools and teachers, and the influence of other teachers. However, there were concerns that need to be taken into consideration in future policy; for example, the quality and type of professional development and resources, curriculum and teacher overload, and teachers' reservations about some aspects of the curriculum documents.

text: Teachers' experiences in curriculum implementation: General curriculum, the arts, and health and physical education This report is part of the National School Sampling Study, a Ministry of Education initiative to investigate how teachers work with the curriculum, 2002-2003. The first report in June 2001 outlined how teacher focus group discussions informed the development of national questionnaires. In April 2002 the research team reported on the first round of questionnaires: general curriculum; mathematics; technology; and Māori medium. A subsequent report in April 2003 outlined the results of questionnaires to investigate teachers' experiences in teaching from the New Zealand national curriculum documents in English, languages (Japanese, Spanish, Chinese, Korean and Samoan), science and social studies.
The major content of this report is the results of another general questionnaire and questionnaires on the arts and health and physical education. The report presents statistical data based upon frequencies and ratios, often organised into school type. Where appropriate, additional comments from `other' categories are presented. Questionnaires included open-ended questions, and results from these are from a sub-sample drawn up for each set of questionnaire responses.
The questionnaires were designed to allow teachers to self-report their curriculum experiences, particularly in using the documents that form a central part of New Zealand's national curriculum: The New Zealand Curriculum Framework (Ministry of Education, 1993), and the statements for the seven curriculum areas which were all relevant to this survey round. Some teachers focused upon the arts or the health and physical education curriculum statements; others on the curriculum generally. Teachers were asked about the documents themselves, professional development, assessment, reporting achievement, school curriculum organisation, the impact of various national curriculum policies, support and resources, and curriculum manageability. They were also encouraged to describe effective aspects of their teaching from the documents, and to reflect upon the impact upon student achievement.
The results show that national curriculum implementation is a complex matter. In general, teachers were reasonably positive about various aspects of their own teaching. Many reported increased confidence in planning, assessment and reporting. The curriculum documents were fairly positively regarded. A number of other factors contributed to teacher confidence such as professional development, resources, review of schools and teachers, and the influence of other teachers. However, there were concerns that need to be taken into consideration in future policy; for example, the quality and type of professional development and resources, curriculum and teacher overload, and teachers' reservations about some aspects of the curriculum documents.

year: 2004

title: Lake weed and the Rotorua Te Arawa Lakes then and now

authors: Burton, Tracy

abstract: This afternoon we will be looking beneath the surface of the Rotorua
Te Arawa lakes at the submerged aquatic plants that grow within them – the good the bad and the ugly. We will have a look at the special native aquatic plants that occur naturally in the lakes, familiarise ourselves with the weed species that have invaded them and look at how these weeds have (and are) changed the natural condition of the lakes. We will also look at how submerged plants are being used to report on the condition of our lakes and what these plant communities can tell us about the state of the lakes yesterday and today.

text: Lake weed and the Rotorua Te Arawa Lakes then and now This afternoon we will be looking beneath the surface of the Rotorua
Te Arawa lakes at the submerged aquatic plants that grow within them – the good the bad and the ugly. We will have a look at the special native aquatic plants that occur naturally in the lakes, familiarise ourselves with the weed species that have invaded them and look at how these weeds have (and are) changed the natural condition of the lakes. We will also look at how submerged plants are being used to report on the condition of our lakes and what these plant communities can tell us about the state of the lakes yesterday and today.

year: 2017