Development and process optimization of batuan [Garcinia binucao (Blanco) Choisy) fruit concentrate using response surface methodology

Following the Box-Behnken Design of the Response Surface Methodology, three (3) different variables namely time, temperature, and extraction (fruit: water ratio), and 15 treatments were used for optimization of processing conditions in batuan concentrate production. The physico-chemical properties (TSS, TA, and pH) of each treatment was determined and used to optimize the processing parameters. Among the three responses, only TSS and TA were chosen for optimization since the model for pH was not significant. The optimum conditions for the batuan concentration process is at time of 150 minutes, temperature of 75ᵒC and fruit:water extraction rate of 60:40. The concentrate under optimum setting was used to evaluate the proximate composition, and simple cost analysis study. The sensory properties of all 15 treatments were evaluated following the incomplete block design by Cochran and Cox (1975). The color was found to have ranged from pale olive green to brown, flavor obtained a score of slightly undesirable to moderately desirable, mouth-feel description varied from slightly perceptible acidity to moderately perceptible acidity, and aroma of the soup have desirable to moderately desirable smell. The acceptability of color, flavor, mouth-fell, and general acceptability obtained a score of 5-7 which all falls under acceptability of neither like nor dislike or like moderately, while the aroma has the acceptability of like slightly to like moderately which has a score of 5.62-7.33. There is no significant difference found in ash and crude fat content of the batuan concentrate and pulp. The moisture content of the concentrate was significantly lower than the pulp, while the protein, fiber, and carbohydrate contents of the concentrate are significantly higher compared to that of the pulp. The total cost in producing batuan concentrate was computed; the cost of 141.67 grams of batuan concentrate was found to be PhP 35.766 approximately equal to 36 peso.