54F-2 |
|
S. DAMAR and M. O. Balaban. Dept. of Food Science and Human Nutrition, Univ. of Florida, 359 FSHN Bldg., Newell Dr., PO Box 110370, Gainesville, FL 32611-0370 Coconut (Cocos nucifera) is a tropical fruit that has a juice with a delicate flavor and highly desirable composition as an isotonic beverage. The shelf life of this “coconut water” is very short. Heating for pasteurization causes loss of flavor, sensory attributes and nutritional value. Therefore, non-thermal methods to extend the shelf life of this product are desirable. Our objectives were to: 1) to develop an acidified and sweetened beverage for refrigerated shelf life, and 2) to find the optimum process parameters that resulted in the highest reduction of microbial loads for this beverage. The pH of the coconut water was 5.1. Since it was above 4.6, any packaged product intended for refrigerated or room temperature storage would be governed by the low acid food regulations. Therefore we decided to acidify the juice to pH=4.3 with malic acid. The resulting sourness required sweetening with Splenda (sucralose). Initial taste tests suggested that the modified juice was better liked if carbonated. Therefore the final product was an acidified, sweetened and carbonated beverage. A continuous dense phase CO2 pasteurizer built by Praxair was used.The process parameters were pressure (13.8, 24.1 and 34.5 MPa), temperature (room temperature, 30 and 40 o C), and percent CO2 in the juice while pasteurized (7, 10, and 13%). Retention time was set to 6 mins.Thermally pasteurized samples (74o C, 15 sec) and controls were also acidified, sweetened and carbonated. Both difference from control and likeability tests were performed.Log reduction of total aerobic plate counts will be presented as a function of process parameters. Sensory results showed that acidified, sweetened and carbonated juice was preferred by panelists.Coconut water modified by acidification, sweetening and carbonation, and pasteurized by dense phase CO2, had a longer shelf life and was more likeable by the sensory panel.
Session 54F, Nonthermal Processing: General I
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |