Texture of Bananas Submitted to Different Freeze Drying Cycle Applying Scanning Electron Microsocopy with Image Analysis Techniques

Abstract

Prediction of texture in bananas submitted to different freeze drying cycle was investigated applying scanning electron microscopy combined with image analysis technique. Freeze drying was performed at different cycles. Microstructure was analyzed using a Scanning Electron Microscopy; Texture parameters were analyzed by Gray Level Co-Matrix Analysis and by conventional analysis; colour by image analysis and porosity by conventional technique. Micrographs revealed that a higher porous size structure was obtained when freeze drying cycles was performed at shorter cycles. Significant difference (P < 0.0001) were obtained for texture, senescence and porosity. A linear trend with a linear correlation was applied for instrumental vs. image texture. Results showed that image features (contrast, correlation, entropy, energy and homogeneity) correlated with mechanical texture. When short cycles were applied minimum damage on texture and senescence parameters appeared. Prediction of texture can be performed easily as a quantitative and non invasive technique that could be related in future studies for quality.