"Research on Dehydrated Fruit Leathers: A Review"

QUINTERO RUIZ, NATALIA A.; DEMARCHI, SILVANA M.; GINER, SERGIO A.

Atenas

Congreso; 11th International Congress on Engineering and Food - "Food Process Engineering in a Changing World"; 2011

National Technical University of Athens, School of Chemical Engineering

Fruit leathers are pectic gels obtained by dehydrating fruit purees to produce restructured, attractive flexible sheets which retain shape and are eaten as snack or dessert. Home preparation is usual to preserve fruits, while some commercial brands offer thin bars of diverse composition, with or without real fruit solids. These products add variety to a healthy diet and possess dietary fibre, vitamins and minerals while providing a good energy intake. Fruit leathers are prepared from fluid-like formulations placed in trays and dehydrated in hot-air dryers at 60-80 ºC and 2-4 m/s. The formulation usually consists of fruit puree added with sucrose or glucose syrup to increase sweetness, solids content, and to reinforce the sugar-acid-high methoxyl pectin gelation. Besides, citric acid may be added to decrease the pH below 3.5. At low pH, carboxyl groups of pectins are undissociated and participate in hydrogen bonds that support gel structure. Investigations on fruit leathers began in 1978 and kept an irregular pace, except in the last five years. The aim of this work is to review published research on fruit leathers in order to summarize available information on formulations, sorptional equilibrium, drying kinetics, quality indices and nutritional retention in relation to the drying technique utilized, being this useful to industry and health-conscious consumers.