QUALITY STABILITY ASSESSMENT OF A STRAWBERRY‐GEL PRODUCT DURING STORAGE

Abstract

ABSTRACT A strawberry‐gel product was formulated by using osmotic treatment. The osmotic solution (OS) used to dehydrate the fruit was mixed with carrageenan and employed to formulate the gel. In order to prevent a further dehydration of the fruit during product storage, the OS was previously diluted so that its water activity is the same as the dehydrated fruit. Changes in water, soluble solids, citric acid, ascorbic acid and anthocyanin contents, water activity, surface color, mechanical properties and volatile profile during 15 days of storage (5C) were evaluated. The use of the OS increased the nutritive and functional properties of the product. Changes in volatile profile, mechanical properties and color of the strawberry occur mainly in the first 2 days of storage and are not due to the presence of the gel matrix, as they occur also in the samples not placed in gel. The flux of anthocyanins from the fruit to the gel produces redness, giving a more attractive aspect to the formulated product. PRACTICAL APPLICATIONSFruit is still consumed below the recommended values for human health, particularly in developed countries. The development of new fruit based products with a high proportion of fruit and good nutritional and functional properties (such as the one proposed in this study) may be of interest in order to diversify the market supply. These products must be attractive, especially among the young, easy to consume and with a reasonable shelf‐life. Osmotic dehydration may be used to partially decrease fruit water activity obtaining high quality products. However, the osmotic solution is still difficult to manage in some cases. Thus, the use of this by‐product on the fruit‐gel formulation is of great interest to eliminate environmental adverse effects and to increase the nutritive and functional properties of the product.