title: Effects of freezing, freeze drying and convective drying on in vitro gastric digestion of apples.
abstract: The influence of processing (freezing at -196°C in liquid N2, FN sample; freeze-drying at -50°C and 30Pa, FD sample; and convective drying at 60°C and 2m/s, CD sample) on apple (var. Granny Smith) behavior during in vitro gastric digestion was investigated. Dried apples (FD and CD samples) were rehydrated prior to digestion. Changes in carbohydrate composition, moisture, soluble solids, acidity, total polyphenol content (TPC), and antioxidant activity (AA) of apple samples were measured at different times during digestion. Processing resulted in disruption of the cellular structure during digestion, as observed by scanning electron microscopy, light microscopy, and changes in carbohydrate composition. Moisture content increased (6-11% dmo), while soluble solids (55-78% dmo), acidity (44-72% dmo), total polyphenol content (30-61% dmo), and antioxidant activity (41-87%) decreased in all samples after digestion. Mathematical models (Weibull and exponential models) were used to better evaluate the influence of processing on apple behavior during gastric digestion.
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Ctra. Valldemossa km. 7.5, 07122 Palma de Mallorca, Spain.
authors.forename: Maria Esperanza
authors.initials: ME
authors.lastname: Dalmau
authors.affiliation: Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA.
authors.forename: Gail M
authors.initials: GM
authors.lastname: Bornhorst
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Ctra. Valldemossa km. 7.5, 07122 Palma de Mallorca, Spain.
authors.forename: Valeria
authors.initials: V
authors.lastname: Eim
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Ctra. Valldemossa km. 7.5, 07122 Palma de Mallorca, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Rosselló
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Ctra. Valldemossa km. 7.5, 07122 Palma de Mallorca, Spain. Electronic address: susana.simal@uib.es.
authors.forename: Susana
authors.initials: S
authors.lastname: Simal
mesh_terms: D000975:Antioxidants; D004063:Digestion; D005612:Freeze Drying / Q000379:methods*; D005615:Freezing; D005638:Fruit / Q000737:chemistry*; D066298:In Vitro Techniques; D027845:Malus / Q000737:chemistry*
chemical_list: D000975:Antioxidants
keywords: Antioxidant activity; Food processing; In vitro gastric digestion; Mathematical model; Microstructure; Polyphenol content