Response surface methodology using mixture design was used to determine the
optimum ratio of pineapple, papaya and carambola in the formulation of red
uced calorie tropical mixed fruit jam. Ten formulations covering the entire
range of a triangular simplex were subjected to sensory evaluation. Contou
r plot of sensory attributes showed that formulations containing 3.5-37.7%
papaya, 0-15% carambola and 61.5-96.5% pineapple produced optimum acceptanc
e. A predicted optimum formulation containing 71% pineapple, 25% papaya and
4% carambola together with two non-optimal formulations were selected and
subjected to sensory evaluation to confirm the validity of the model. There
was a significant difference (P less than or equal to 0.05) between the pr
edicted optimum and the other two tested formulations. Results obtained mat
ched the predicted value where the optimum formulation received the best se
nsory scores for most attributes tested. The optimum mixed fruit jam formul
ation contained 106 kcal/100g which is one-third of the caloric value of a
normal jam. (C) 2001 Elsevier Science Ltd. Ail rights reserved.