title: Production of volatiles in fresh-cut apple: effect of applying alginate coatings containing linoleic acid or isoleucine.
abstract: One of the main quality parameters in apples is aroma, its main precursors are fatty acids (FA) and amino acids (AA). In this study, alginate edible coatings were used as carriers of linoleic acid or isoleucine to serve as precursors for the production of aroma in cut apples. Apple wedges were immersed in a CaCl2 solution and coated with one of the following formulations: alginate solution (Alg-Ca), Alg-Ca-low-level linoleic acid (0.61 g/Lt), (LFA), Alg-Ca-high-level linoleic acid (2.44 g/L; HFA), Alg-Ca-low-level isoleucine (0.61 g/L; LAA), and Alg-Ca-high-level isoleucine (2.44 g/L; HAA). Apple wedges were stored at 3 °C and 85% relative humidity for 21 d and key volatiles were studied during storage. Addition of precursors, mainly isoleucine, showed to increase the production of some key volatiles on coated fresh-cut apples during storage. The concentration of 2-methyl-1-butanol was 4 times higher from day 12 to day 21 in HAA, while 2-methyl butyl acetate increased from day 12 to day 21 in HAA. After 21 d, HAA-apples presented a 40-fold value of 2-methyl-butyl acetate, compared to Alg-Ca cut apples. Values of hexanal increased during cut apple storage when the coating carried linoleic acid, mainly on HFA, from 3 to 12 d. The ability of apples to metabolize AA and FA depends on the concentration of precursors, but also depends on key enzymes, previous apple storage, among others. Further studies should be done to better clarify the behavior of fresh-cut apples as living tissue to metabolize precursors contained in edible coatings for the production of volatiles.
authors.affiliation: Facultad de Ciencias Agrotecnológicas, Univ. Autónoma de Chihuahua, Av. Presa de la Amistad S/N, Cuauhtémoc, Chih., México.
authors.forename: Irma O
authors.initials: IO
authors.lastname: Maya-Meraz
authors.forename: Miguel
authors.initials: M
authors.lastname: Espino-Díaz
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Molina-Corral
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: González-Aguilar
authors.forename: Juan L
authors.initials: JL
authors.lastname: Jacobo-Cuellar
authors.forename: David R
authors.initials: DR
authors.lastname: Sepulveda
authors.forename: Guadalupe I
authors.initials: GI
authors.lastname: Olivas
mesh_terms: D000464:Alginates / Q000737:chemistry*; D005503:Food Additives / Q000737:chemistry; D005519:Food Preservation / Q000379:methods*; D005638:Fruit / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007532:Isoleucine / Q000737:chemistry*; D019787:Linoleic Acid / Q000737:chemistry*; D027845:Malus / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000464:Alginates; D005503:Food Additives; D006603:Hexuronic Acids; D055549:Volatile Organic Compounds; D007532:Isoleucine; D020723:Glucuronic Acid; D019787:Linoleic Acid
keywords: apple; edible coating; fresh-cut; precursors; volatile compounds