Affiliations: [a] Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA), CONICET - La Plata, Facultad de Ciencias Exactas Universidad Nacional de La Plata(UNLP), Buenos Aires, Argentina
| [b] Consejo Nacionalde Investigaciones Científicas y Técnicas (CONICET), Argentina
Corresponding author: María Cecilia Lanari, Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA), CONICET - La Plata, Facultad de Ciencias Exactas Universidad Nacional de La Plata (UNLP), Calle 47 y 116 S/N°, La Plata (B1900AJJ), Buenos Aires, Argentina. Tel.: +0054 221 4254853/4249287/4890741; E-mail: [email protected].
Abstract: BACKGROUND:Arazá, a tropical berry rich in thermolabile antioxidants (ascorbic-acid/phenolics/flavonoids/carotenoids), is a potential ingredient for preparing functional foods; however, its high perishability hinders its industrial application. Osmotic-dehydration (OD), a processing method that operates at low temperature ranges, may be adequate for improving arazá's shelf-life without reducing its palatability/nutritional quality. Physicochemical and nutritional properties depend on the time/temperature/osmotic-solution concentration applied; therefore, parameters optimization is required. Processing selection must also consider treatment effect on antioxidants composition/activity/bioaccessibility in the gastro-intestinal (GI) tract, key factors in bioactives health benefits. OBJECTIVES:a) Optimize OD duration/temperature/sucrose concentration to maximize process efficiency/total-polyphenol content/overall-acceptability using principal component analysis and Response-Surface-Methodology/Desirability-Function.b) Determine OD effect on antioxidant content/activity/bioaccessibilities before and after gastro-intestinal digestion. RESULTS AND CONCLUSIONS:Processing conditions have opposite effects on sensory and chemical properties; reaching antioxidant content/activity highest levels in the osmo-dehydrated fruit required 60 min/20°Bx; whereas, the best organoleptic scores demanded 180 min/60°Bx.Although osmotic-drying reduced the fruit's antioxidant content/activity 39–76%, the process improved antioxidants bioaccessibilities, since these values were: 63–85% (untreated fruit) and 72–90% (osmodehydrated arazá (ODA)), whereas the activity retention levels were 67–76% (untreated fruit/ODA).