Influence of drying methods on the structure, mechanical and sensory properties of strawberries

Abstract

To extend the shelf life of food, structural, sensory or mechanical properties are analysed to provide superlative quality for the dried product. The purpose of this paper is to examine the impact of drying methods and their parameters on the properties of strawberries (their structure, mechanical parameters and sensory profiles). The drying methods influenced the internal structure of strawberries. At the same temperature (45 °C) among various drying methods, strawberries obtained by vacuum drying (VD) had higher hardness than convective-dried fruits (AD), but it was significantly lower compared to freeze-dried samples (FD). Increase in temperature in the VD method caused changes in the hardness of dried fruits. They differed in the sensory profile including: appearance, texture and taste/flavour. The lowest intensity of cooked strawberries aroma with high intensity of fresh strawberries flavour, higher level of sour taste and lower sweetness were obtained in FD. By lowering the temperature in VD, the sensation of crispness or crunchiness decreased, and the intensity for gumminess, the impression of aroma of cooked or fresh strawberries increased. The highest correlations between sensory and mechanical properties were noted for VD fruits dried at temperature of 55 °C and set pressure of 4 kPa.