Gelling effect of gracilaria debilis agar in the elaboration of a sapodilla (manilkara zapota) compote

Abstract

Agar is a used in the food industry for its stabilization and gelation characteristics and the medlar is a fruit with a pleasant taste, easy to consume where it provides excellent nutritional properties. In this study the effect of gelling extracted Gracilaria debilis agar was evaluated in the formulating a sapodilla (Manilkara zapota) compote. Agar was extracted from the collected algae by alkaline treatment with 0.04 M NaOH. To obtain compote, three base formulas were prepared, selected which containing 0.05% citric acid, 56.4% water, 6.0% sugar and 37.6% sapodilla puree; providing the basis for three samples (M1, M2 and M3) at the following concentrations: 0.4%; 0.6% and 0.8% w/w of agar, respectively. Sensory analysis indicated that the compote M2 had the most acceptable values, with ash content= 0.85±0.08%; chloride= 0.085±0.014%; 18.0±0,4 °Brix; fat= 0.50±0.01 g/100 g; humidity= 64.0±3.0%; pH= 4.32±0.03; protein= 0,42±0.01 g/100 g and total solids= 35.9±3.0%. The viscosity (-554±10 gs) was close to the value of a commercial compote (-430±4 gs). M2 showed stability for one month, against the aerobic mesophilic bacteria, with values less than 10 CFU/mL. It was observed that agar concentrations had influenced only in the viscosity by adjusting to a linear equation with R2= 0.986. In foods that require high temperatures in their preparation, such as compotes, agar has properties as well as the adequate behavior as a gelling agent.