USE OF FACTORIAL DESIGN METHODOLOGY IN FRUIT JUICE QUALITY RETENTION STUDIES

It is the responsibility of the juice manufac-turers to ensure that quality losses in juice are minimal. The manufacturer must seek to monitor the factors which influence the ascorbic acid level under production, distri-bution and storage conditions. To predict the extent of deterioration of nutrient value, a knowledge of the loss of important nutri-tive quality index as a function of the dete-riorative factors are needed (Owen, 1976; Philip, 2005). Through modeling of the vari-ous deteriorative factors, the juice manufac-turer can specify the value of his product, which is essential, if nutrient claims are to be made on the label or advertising associated Deterioration of fruit juice, an inherent problem that tends to impede the development of the fruit juice industry, is influenced by many variables in processing, handling, storage and distribution. Ascorbic acid is the least stable of all fruit juice nutrients, it is readily oxidized. Thus, its concentration is an in-dex to the retention of the original nutritive value. The use of factorial design methodology in monitor-ing the degradation of ascorbic acid in fruit juices during ambient storage and distribution is presented in this work. The effects of storage temperature, brix value, pH, quantity of antioxidant and duration of storage on the ascorbic acid levels in orange, mango and pineapple juices, under non-refrigerated storage and distribution were investigated; optimal shelf-life and quality value models were developed. Data were drawn from a full factorial experiments conducted in three replicates with the order of the replicate experiments randomized. Multivariate re-gression analysis was used for relating the variables. The optimal shelf-lives of the orange, and pine-apple juices was 16 days and the respective values of ascorbic acid for this duration were 22.93mg\100ml, 25.89mg\100ml, and 11.69mg\100ml. The regression analysis model confirmed the mango juice model to be inadequate