title: The role of peracetic acid in bloodmeal decoloring

authors: Hicks, Talia

subjects: co-products (Waste)

abstract: Hydrogen peroxide (HP) can degrade soluble heme, forming yellow or colorless degradation products. Thermal treatment during bloodmeal production changes the conformation of oxyhemoglobin trapping heme in hydrophobic protein regions or forms methemoglobin (metHb) heme which catalytically removes HP. As a result, HP can only degrade a portion of the heme present in bloodmeal leading to poor decoloring. Equilibrium peracetic acid (PAA) solutions can effectively decolor bloodmeal. This work assessed the ability of PAA to decolor bloodmeal and the mechanism by which it occurs. The inability of HP to decolor bloodmeal is determined by the fact that it is unable to permanently degrade metHb heme, or hydrophobically trapped heme. Addition of organic acids to HP led to significant swelling of the protein chains but also to poorer decoloring and lower HP consumption compared to PAA. This suggested that in the case of PAA solutions, where bleaching was facile, the reason PAA solutions are capable of decoloring bloodmeal was due to the action of the PAA molecule against heme, whereas HP and acetic (ethanoic) acid played only minor roles in total bleaching. The decolored protein powder has reduced odor and whiter color, and is suitable for applications such as bioplastics.

text: The role of peracetic acid in bloodmeal decoloring Hydrogen peroxide (HP) can degrade soluble heme, forming yellow or colorless degradation products. Thermal treatment during bloodmeal production changes the conformation of oxyhemoglobin trapping heme in hydrophobic protein regions or forms methemoglobin (metHb) heme which catalytically removes HP. As a result, HP can only degrade a portion of the heme present in bloodmeal leading to poor decoloring. Equilibrium peracetic acid (PAA) solutions can effectively decolor bloodmeal. This work assessed the ability of PAA to decolor bloodmeal and the mechanism by which it occurs. The inability of HP to decolor bloodmeal is determined by the fact that it is unable to permanently degrade metHb heme, or hydrophobically trapped heme. Addition of organic acids to HP led to significant swelling of the protein chains but also to poorer decoloring and lower HP consumption compared to PAA. This suggested that in the case of PAA solutions, where bleaching was facile, the reason PAA solutions are capable of decoloring bloodmeal was due to the action of the PAA molecule against heme, whereas HP and acetic (ethanoic) acid played only minor roles in total bleaching. The decolored protein powder has reduced odor and whiter color, and is suitable for applications such as bioplastics.

year: 2013

title: An evaluation of mixed methods (diaries and focus groups) when working with older people

authors: Koopman-Boyden, Peggy G.

subjects: mixed methods

abstract: This paper considers the advantages and limitations of using mixed methods, diaries and focus groups in research with older people, specifically research investigating the interaction experiences of older individuals as customers, members and workers with public-, private- and community-based organisations. Drawing on the literature on mixed method integration, five distinct advantages were identified: development, completeness, expansion, offsetting and initiation. Two limitations were also noted: demands of the data collection on the participants and insufficient depth. Each is discussed in the context of the particular research project, with the suggestion that mixed methods be used in future research with older people.

text: An evaluation of mixed methods (diaries and focus groups) when working with older people This paper considers the advantages and limitations of using mixed methods, diaries and focus groups in research with older people, specifically research investigating the interaction experiences of older individuals as customers, members and workers with public-, private- and community-based organisations. Drawing on the literature on mixed method integration, five distinct advantages were identified: development, completeness, expansion, offsetting and initiation. Two limitations were also noted: demands of the data collection on the participants and insufficient depth. Each is discussed in the context of the particular research project, with the suggestion that mixed methods be used in future research with older people.

year: 2012

title: Kai whakakitenga-nui te whakatōhea: Whenua planning for kai security

authors: Maxwell, Te Kahautu

abstract: To exercise Tino Rangatiratanga in our pursuit to define our local food systems through the traditional knowledge and practice of growing kai that will inspire and transform the health and well-being of all Whakatōhea, Whānau, Hapū, Iwi.

text: Kai whakakitenga-nui te whakatōhea: Whenua planning for kai security To exercise Tino Rangatiratanga in our pursuit to define our local food systems through the traditional knowledge and practice of growing kai that will inspire and transform the health and well-being of all Whakatōhea, Whānau, Hapū, Iwi.

year: 2025