Influence of Xanthan Gum on the Structural Characteristics of Myofibrillar Proteins Treated by High Pressure C: Food Chemistry
Gina Villamonte, Vanessa Jury, St´ephanie Jung, and Marie de Lamballerie
Abstract: The effects of xanthan gum on the structural modifications of myofibrillar proteins (0.3 M NaCl, pH 6) induced by high pressure (200, 400, and 600 MPa, 6 min) were investigated. The changes in the secondary and tertiary structures of myofibrillar proteins were analyzed by circular dichroism. The protein denaturation was also evaluated by differential scanning calorimetry. Likewise, the protein surface hydrophobicity and the solubility of myofibrillar proteins were measured. High pressure (600 MPa) induced the loss of α-helix structures and an increase of β-sheet structures. However, the presence of xanthan gum hindered the former mechanism of protein denaturation by high pressure. In fact, changes in the secondary (600 MPa) and the tertiary structure fingerprint of high-pressure-treated myofibrillar proteins (400 to 600 MPa) were observed in the presence of xanthan gum. These modifications were confirmed by the thermal analysis, the thermal transitions of high-pressure (400 to 600 MPa)-treated myofibrillar proteins were modified in systems containing xanthan gum. As consequence, the high-pressure-treated myofibrillar proteins with xanthan gum showed increased solubility from 400 MPa, in contrast to high-pressure treatment (600 MPa) without xanthan gum. Moreover, the surface hydrophobicity of high-pressure-treated myofibrillar proteins was enhanced in the presence of xanthan gum. These effects could be due to the unfolding of myofibrillar proteins at high-pressure levels, which exposed sites that most likely interacted with the anionic polysaccharide. This study suggests that the role of food additives could be considered for the development of meat products produced by high-pressure processing. Keywords: High-pressure processing, myofibrillar protein, protein structure, xanthan gum
Myofibrillar proteins are responsible for the textural properties of meat products. Xanthan gum modifies structural characteristics of myofibrillar proteins treated by high pressure, which could affect their functional properties. Protein denaturation by high pressure (400 to 600 MPa) in presence of xanthan gum improves protein solubilization. Solubilization of myofibrillar proteins is an essential step for meat emulsion and gel formation.
Practical Application:
Introduction The quality of meat products is related to conformational changes of myofibrillar proteins under specific conditions, such as pH, ionic strength, ingredients, additives, and processes (Sun and Holley 2011). Understanding the role of these factors is crucial to develop novel meat products with reduced fat and sodium content. Polysaccharides have been used as fat replacers (Jim´enezColmenero and others 2013; Keenan and others 2014) and to improve technological characteristics (Bengtsson and others 2011; Rodriguez Furl´an and others 2014) or enhance meat protein functionality (Shang and Xiong 2010). The interaction between meat proteins and polysaccharides (flaxseed gum, xanthan gum, and chitosan) has been demonstrated and has been associated with improved gel characteristics (Chen and others 2007; Shang and Xiong 2010; Sun and others 2011). Xanthan gum is an anionic polysaccharide that can hinder the gel formation of myofibrillar proteins (Xiong and Blanchard 1993). However, in the presence of MS 20141225 Submitted 7/16/2014, Accepted 12/12/2014. Authors Villamonte, Jury, and de Lamballerie are with ONIRIS, Food Process Engineering, UMR CNRS 6144 GEPEA, CS 82225, 44322 Nantes Cedex 3, France. Author Jung is with Dept. of Food Science and Human Nutrition, Iowa State Univ. Ames, IA 50011, U.S.A. Direct inquiries to author de Lamballerie (E-mail: [email protected]).
C522
Journal of Food Science r Vol. 80, Nr. 3, 2015
transglutaminase, xanthan gum enhances gel strength and reduces the exudation of heat-induced myofibrillar proteins gels (Shang and Xiong 2010). High-pressure processing as a texturing technology can assist in obtaining meat products with lower sodium content by the improved extraction of salt-soluble proteins (Sikes and others 2009; Duranton and others 2012). The tenderness or toughness of meat products after high-pressure processing is the result of structural modifications of meat proteins. The effect of high pressure on the noncovalent bonds promotes the dissociation, aggregation, or gelation of proteins (Lullien-Pellerin and Balny 2002; Yamamoto and others 2002). High pressure causes the denaturation of myofibrillar proteins at nondenaturing temperatures with a different mechanism compared to the heat treatment (Fernandez-Martin 2007; Lee and others 2007). The structural modifications of myofibrillar proteins by high pressure are strongly influenced by the pressure level, the treatment temperature, and the ionic strength (Macfarlane and McKenzie 1976; Yamamoto and others 2002; Jim´enez-Colmenero 2002; Chapleau and others 2004; Lee and others 2007; Cao and others 2012). Nevertheless, there is not enough information on the impact of food additives on myofibrillar proteins modifications when processed by high pressure. Previously, a protective role of the complex formation had been reported between proteins and polysaccharides (serum albumin R C 2015 Institute of Food Technologists
doi: 10.1111/1750-3841.12789 Further reproduction without permission is prohibited
High pressure on meat proteins + xanthan . . .
Materials and Methods
an ionic strength (0.3 M NaCl) similar to the ionic strength of the postmortem muscle.
High-pressure treatment The samples were treated (200, 400, or 600 MPa) for 6 min in a 3-L high-pressure pilot unit (ACB, Nantes, France) at room temperature (20 ± 4°C). The vessel was equipped with a cooling water jacket and a temperature regulator device (Julabo, Seelbach, Germany). The level of pressure was reached at 3 MPa/s and then released almost instantaneously (
Gina Villamonte, Vanessa Jury, St´ephanie Jung, and Marie de Lamballerie
Abstract: The effects of xanthan gum on the structural modifications of myofibrillar proteins (0.3 M NaCl, pH 6) induced by high pressure (200, 400, and 600 MPa, 6 min) were investigated. The changes in the secondary and tertiary structures of myofibrillar proteins were analyzed by circular dichroism. The protein denaturation was also evaluated by differential scanning calorimetry. Likewise, the protein surface hydrophobicity and the solubility of myofibrillar proteins were measured. High pressure (600 MPa) induced the loss of α-helix structures and an increase of β-sheet structures. However, the presence of xanthan gum hindered the former mechanism of protein denaturation by high pressure. In fact, changes in the secondary (600 MPa) and the tertiary structure fingerprint of high-pressure-treated myofibrillar proteins (400 to 600 MPa) were observed in the presence of xanthan gum. These modifications were confirmed by the thermal analysis, the thermal transitions of high-pressure (400 to 600 MPa)-treated myofibrillar proteins were modified in systems containing xanthan gum. As consequence, the high-pressure-treated myofibrillar proteins with xanthan gum showed increased solubility from 400 MPa, in contrast to high-pressure treatment (600 MPa) without xanthan gum. Moreover, the surface hydrophobicity of high-pressure-treated myofibrillar proteins was enhanced in the presence of xanthan gum. These effects could be due to the unfolding of myofibrillar proteins at high-pressure levels, which exposed sites that most likely interacted with the anionic polysaccharide. This study suggests that the role of food additives could be considered for the development of meat products produced by high-pressure processing. Keywords: High-pressure processing, myofibrillar protein, protein structure, xanthan gum
Myofibrillar proteins are responsible for the textural properties of meat products. Xanthan gum modifies structural characteristics of myofibrillar proteins treated by high pressure, which could affect their functional properties. Protein denaturation by high pressure (400 to 600 MPa) in presence of xanthan gum improves protein solubilization. Solubilization of myofibrillar proteins is an essential step for meat emulsion and gel formation.
Practical Application:
Introduction The quality of meat products is related to conformational changes of myofibrillar proteins under specific conditions, such as pH, ionic strength, ingredients, additives, and processes (Sun and Holley 2011). Understanding the role of these factors is crucial to develop novel meat products with reduced fat and sodium content. Polysaccharides have been used as fat replacers (Jim´enezColmenero and others 2013; Keenan and others 2014) and to improve technological characteristics (Bengtsson and others 2011; Rodriguez Furl´an and others 2014) or enhance meat protein functionality (Shang and Xiong 2010). The interaction between meat proteins and polysaccharides (flaxseed gum, xanthan gum, and chitosan) has been demonstrated and has been associated with improved gel characteristics (Chen and others 2007; Shang and Xiong 2010; Sun and others 2011). Xanthan gum is an anionic polysaccharide that can hinder the gel formation of myofibrillar proteins (Xiong and Blanchard 1993). However, in the presence of MS 20141225 Submitted 7/16/2014, Accepted 12/12/2014. Authors Villamonte, Jury, and de Lamballerie are with ONIRIS, Food Process Engineering, UMR CNRS 6144 GEPEA, CS 82225, 44322 Nantes Cedex 3, France. Author Jung is with Dept. of Food Science and Human Nutrition, Iowa State Univ. Ames, IA 50011, U.S.A. Direct inquiries to author de Lamballerie (E-mail: [email protected]).
C522
Journal of Food Science r Vol. 80, Nr. 3, 2015
transglutaminase, xanthan gum enhances gel strength and reduces the exudation of heat-induced myofibrillar proteins gels (Shang and Xiong 2010). High-pressure processing as a texturing technology can assist in obtaining meat products with lower sodium content by the improved extraction of salt-soluble proteins (Sikes and others 2009; Duranton and others 2012). The tenderness or toughness of meat products after high-pressure processing is the result of structural modifications of meat proteins. The effect of high pressure on the noncovalent bonds promotes the dissociation, aggregation, or gelation of proteins (Lullien-Pellerin and Balny 2002; Yamamoto and others 2002). High pressure causes the denaturation of myofibrillar proteins at nondenaturing temperatures with a different mechanism compared to the heat treatment (Fernandez-Martin 2007; Lee and others 2007). The structural modifications of myofibrillar proteins by high pressure are strongly influenced by the pressure level, the treatment temperature, and the ionic strength (Macfarlane and McKenzie 1976; Yamamoto and others 2002; Jim´enez-Colmenero 2002; Chapleau and others 2004; Lee and others 2007; Cao and others 2012). Nevertheless, there is not enough information on the impact of food additives on myofibrillar proteins modifications when processed by high pressure. Previously, a protective role of the complex formation had been reported between proteins and polysaccharides (serum albumin R C 2015 Institute of Food Technologists
doi: 10.1111/1750-3841.12789 Further reproduction without permission is prohibited
High pressure on meat proteins + xanthan . . .
Materials and Methods
an ionic strength (0.3 M NaCl) similar to the ionic strength of the postmortem muscle.
High-pressure treatment The samples were treated (200, 400, or 600 MPa) for 6 min in a 3-L high-pressure pilot unit (ACB, Nantes, France) at room temperature (20 ± 4°C). The vessel was equipped with a cooling water jacket and a temperature regulator device (Julabo, Seelbach, Germany). The level of pressure was reached at 3 MPa/s and then released almost instantaneously (
