title: Molecular structural differences between low methoxy pectins induced by pectin methyl esterase II: effects on texture, release and perception of aroma in gels of similar modulus of elasticity.
abstract: Six low-methoxy pectins with different degrees of methylesterification and amidation, and molecular weights were used to prepare gels with similar moduli of elasticity by varying the concentrations of pectin and calcium phosphate. Five aroma compounds were added to the gels and their sensory textural properties, release and perception of aromas were investigated. Sensory firmness, springiness, adhesiveness, chewiness and cohesiveness differed according to the gel type, even though the moduli of elasticity were not significantly different (p<0.05). Release and perception of aromas also displayed significant difference according to the gel type (p<0.05). Low-methoxy amidated pectin exhibited the lowest release and perception for all the aroma compounds, while pectin-methylesterase-treated pectin gels exhibited relatively higher aroma release and perception. These results showed that the structural properties of pectins and gelling factors that increase the non-polar character of the gel matrices could decrease the release and perception of aromas in pectin gel systems.
authors.affiliation: Department of Food Science and Engineering, Ewha Womans University, Seoul 120-750, Republic of Korea.
authors.forename: Yang
authors.initials: Y
authors.lastname: Kim
authors.forename: Young-Suk
authors.initials: YS
authors.lastname: Kim
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Yoo
authors.forename: Kwang-Ok
authors.initials: KO
authors.lastname: Kim
mesh_terms: D000577:Amides / Q000737:chemistry; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D055598:Chemical Phenomena; D032084:Citrus sinensis / Q000201:enzymology; D004044:Dietary Proteins / Q000737:chemistry* / Q000378:metabolism; D055119:Elastic Modulus; D005260:Female; D005511:Food Handling; D005526:Food, Formulated / Q000032:analysis*; D005638:Fruit / Q000201:enzymology; D005782:Gels; D006801:Humans; D055595:Mechanical Phenomena; D008745:Methylation; D008970:Molecular Weight; D009812:Odorants; D010368:Pectins / Q000737:chemistry* / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D025341:Principal Component Analysis; D011487:Protein Conformation; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000378:metabolism; D014835:Volatilization
chemical_list: D000577:Amides; D004044:Dietary Proteins; D005782:Gels; D010940:Plant Proteins; D055549:Volatile Organic Compounds; D010368:Pectins; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase
keywords: Aroma release; Degree of amidation; Degree of methylesterification; Gel strength; Perception