Physical, chemical and sensorial properties of kiwi as influenced by drying conditions
Keywords:Antioxidant activity, colour, drying, phenolic compounds, sensorial analysis, texture, vitamin C.
The present study aimed at studying the effect of convective air drying in some physical, chemical and sensorial properties of kiwi samples. For that the kiwis were dried in thin layer in convective chambers set to constant temperatures of 50, 60, 70 and 80 ºC. The fresh as well as the dried samples were analysed for moisture, water activity, vitamin C, total phenolic compounds, antioxidant activity, colour and texture. Also the different dried samples were subjected to a sensorial analysis.
It was concluded drying of kiwi importantly decreased the contents in some bioactive components like vitamin C and phenolic compounds as well as the antioxidant activity. Moreover, the negative impact was higher for higher drying temperatures. Drying also altered the colour towards a lower intensity of the green colouration and a higher intensity of the yellow. In what concerns the textural properties, again drying produced important alterations; however the influence of temperature was not visible. Regarding the sensorial evaluation, even though it allowed establishing the sensory profiles of the dried samples, it was not possible to clearly distinguish among them, and particularly in what related to the global appreciation.