Evaluation of the effects of season on yield, viscosity and colour of tomato, watermelon and pineapple pulps and blends

This paper evaluates the effect of production season on pulp yield, apparent viscosity and colour of tomato ( Lycopersiconesculentum var. Roma VF), watermelon ( Vitrullus vulgaris var. Babyblack) and pineapple ( Ananascomosus var. Smooth cayennes) pulps. Tomato, watermelon and pineapple pulps from two harvesting seasons (January and April) were blended in the ratios 1:1:1, 1:1:2 and 2:1:1 (v/v/v) to produce a phytochemically active fruit pulp blends. Apparent viscosities and colour were determined using a digital rotational viscometer and Macbeth Munselltristimulus disc colorimeter, respectively. Apparent viscosity of the blends was in the range 25.90 - 37.90 cPa.s and 25.30 - 30.20cPa.s in the January and April batch, respectively. Thea – values of the blends were between 26.34 – 28.41and 25.99 – 28.89 for January and April batch, 2 respectively. The highest redness factor (a/b) , of 2.50 was recorded for tomato pulp in the April batch and the blends' total color difference (ΔE) ranged between 1.93 and 8.46.The study showed seasonal variation in pulp yield, apparent viscosity and colour and the consistency of the blends.