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Understanding interactions in wet alginate film formation used for in-line food processes

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dc.contributor.advisor Barbut, Shai Harper, Bonnie Allison 2013-12-10T21:10:34Z 2013-12-10T21:10:34Z 2013-11 2013-11-22 2013-12-10
dc.description.abstract Recently some major sausage manufacturers have begun using co-extruded alginate, collagen, or alginate-collagen hybrid casings for their sausage products. Despite their use commercially, little is known about co-extruded alginate casings. In this study ‘wet’ alginate films (~ 90-95 % water content) were used as a model to understand co-extruded alginate casings. The study examined how various proteins (gelatin, soy, heated and unheated whey protein) and carbohydrates (iota- and kappa- carrageenan, low methoxyl pectin, modified and unmodified potato starch, commercial and extracted cellulose, or gellan gum) affected the mechanical and microstructural properties of ‘wet’ alginate films. Pectin, carrageenan, and modified potato starch increased (P < 0.05) the tensile elongation of the films, while soy protein, whey protein, modified potato starch, and cellulose decreased (P < 0.05) the puncture strength of the films. These results suggest that the mechanical properties of ‘wet’ alginate films can be altered by adding various proteins and carbohydrates to the films. The type of divalent cation (Ba2+, Ca2+, Mg2+, Sr2+, or Zn2+) used to gel the alginate and the presence of added NaCl in the alginate solution also affected (P < 0.05) the mechanical properties of the films. In the transmission electron microscopy images, certain added carbohydrates were easily identifiable in the alginate matrix by their unique morphology while others were less distinguishable. Another objective of the study was to explore the impact of drying the ‘wet’ alginate films. As expected, the dried films (conditioned at both 57 % and 100 % RH) had very different mechanical properties than their corresponding ‘wet’ films. Several peak shifts in the Fourier transform infrared spectra were observed when the alginate, alginate-pectin, and alginate-kappa-carrageenan solutions were gelled and dried. Differences (P < 0.05) in the mechanical properties of the dried films conditioned at 57 % and 100 % RH were also observed. These differences were attributed to the plasticizing effect of water in the films. Understanding the characteristics of ‘wet’ alginate films is important for future development and optimization of these films for use on food products, such as sausages. en_US
dc.description.sponsorship Ontario Ministry of Agriculture, Food and Rural Affairs and the Hannam Soy Utilization Fund en_US
dc.language.iso en en_US
dc.rights Attribution-NonCommercial-NoDerivs 2.5 Canada *
dc.rights.uri *
dc.subject alginate en_US
dc.subject film en_US
dc.subject texture en_US
dc.subject microscopy en_US
dc.subject Fourier transform infrared spectroscopy en_US
dc.title Understanding interactions in wet alginate film formation used for in-line food processes en_US
dc.type Thesis en_US Food Science en_US Doctor of Philosophy en_US Department of Food Science en_US
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Attribution-NonCommercial-NoDerivs 2.5 Canada Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivs 2.5 Canada