Spatio-temporal postharvest changes in texture and fatty acid profiles in avocado fruit from different origins

The degree of ripeness of many climacteric fruits, such as avocado, can be correlated with fleshfirmness and other rheological properties. However, there remains a paucity of information on not only thepostharvest changes in texture of avocado fruit from different origins, but also on the spatial variation in texturewithin individual fruit. In addition, the relationship between changes in texture and lipid profile of fruit tissueduring postharvest ripening is unknown.The aim of the present study was to assess and discriminate between avocado cv. Hass fruit from threedifferent origins (viz. Spain, Peru and Chile) on the basis of temporal and spatial changes in both texture andfatty acid profiles of fruit flesh. Texture of different horizontally-cut slices from individual fruit within aconsignment was measured during ripening using a previously unreported technique. Maximum load, elasticityand viscosity of fruit tissue was measured using an Instron 5542 universal testing machine fitted with either a500 N or 5 N load cell. The same fruit slice was immediately snap-frozen in liquid nitrogen and freeze-driedprior to subsequent extraction, identification and determination of fatty acid methyl esters (FAME) profiles usinggas chromatography coupled to flame ionization detection (GC-FID). The results were used to differentiate avocado fruit into definable groups using partial least squares discriminant analysis. Significant differences inmaximum load, elasticity, viscosity were found in avocado fruit flesh during ripening, and between origins andto a lesser extent between different locations within the fruit. Lipid profiles showed dissimilar compositionaccording to origin and changed slightly from apex to base. The textural changes and lipid profile in avocadofruit is therefore related to origin and the spatial variation within individual fruit.