Factor J had a negative effect on L and b, and a positive effect on
a. This means that at increasing proportions of juice in the
formulation, the jellies obtained were darker, more reddish, and
less yellowish. This was attributed to non-enzymatic (Maillard)
browning during the concentration process, since higher juice
proportions in the ingredients implicated longer cooking times.
Factor P had a negative effect onmb, which means that increasing
concentrations of pectin produced less yellowish jellies. The reason
for this is not clear. It is worth noting that the pH had no significant
effect on any of the physical parameters.
On the other hand, overall acceptability was significantly
affected by juice proportion (J), pH, and soluble solids (SS), in that
order of importance, while pectin concentration (P) had no significant effect on it. Following is the model obtained in terms of the
actual factors, and the corresponding regression coefficients: