39B-40

A. ARGAIZ-JAMET¹, A. Lopez-Malo, and G. Rodriguez-Serrano. (1) Dept. Ingenieria Quimica y Alimentos, Universidad de las Americas-Puebla, Sta. Catarina Martir, Cholula, Puebla, 72820, Mexico

Due to the abundance and highly marked season of prickle pear production the losses are very high and the producers are searching alternatives uses for it.

The objective of this work was to formulate and evaluate the acceptability of a fruit punch containing prickle pear, orange, pineapple or grape juices, or hibiscus extract, maximizing the amount of prickle pear juice on the formulation.

Prickle pear juice (P) was combined with orange (O), pineapple (Pa), grape (G) and hibiscus extract (H) in ternary mixtures containing 60% of prickle pear juice (6 combinations) and ranked for acceptability by 20 untrained judges. The preferred ternary mixture was optimized using a mixture experiment with the restriction that the prickle pear was at least the 50 but no more than 80 % of the mixture. The ten resulting treatments were rated for acceptability on a 9 point hedonic scale by ten semi-trained judges. The mixture components were expressed as pseudo-components to put it in the same scale (0 to 1). The pseudo-components were used in a lineal model and in a Scheffe's prediction model in order to describe and predict the sensorial results.

The ranking results clearly showed that the mixture of prickle pear juice with hibiscus extract and pineapple juice (P:H:Pa) was preferred over the other combinations and was used in the optimization study. Treatments with 65:25:15 and 70:15:15 proportions of P:H:Pa received the higher means scores for acceptability; higher than 7.5 (between liked moderately and liked very much). The acceptability (y) was satisfactorily described (R-square=0.88) by the Scheffe's model:

y=5.72 X1+ 6.66 X2 + 7.51 X3 + 0.64 X1 X2 + 0.42 X1 X3 + 0.15 X2 X3

where X1=Prickle pear juice, X2=Hibiscus extract and X3=Pineapple juice, expressed as pseudo-components in the formulation. The model predicts an optimal mixture with 62.60:11.35:26.05 proportions of P:H:Pa respectively with a maximum acceptability score of 7.93.

Prickle pears can be used to manufacture highly acceptable fruit punch were up to 70 % of prickle pear can be used in the formulation.