Fermentation Studies and Nutritional Analysis of Drinks Made from Water Extract of Hibiscus sabdariffa Calyx (Sobo), Juices of Citrus sinensis (Orange) and Ananas comosus (Pineapple)

摘要

Pure orange juice, pineapple juice and sobo (the water extract of the calyx Hibiscus sabdariffa) as well as sobo-orange and sobo-pineapple mixtures with or without added preservatives have been analyzed for titratable acidity, ascorbic acid and protein contents. The study show that freshly prepared sobo is the most acidic, followed by orange juice, while pineapple juice is the least acidic. The ascorbic acid content (vitamin C) in percent decrease in the order orange juice>sobo>pineapple juice, while the protein content vary in the order sobo>pineapple juice>orange juice. The ascorbic acid content of the mixture increases as the sobo content decreases for both sobo-orange and sobo-pineapple mixtures. The nitrogen and protein contents of sobo-pineapple mixtures were higher than those of sobo-orange mixtures. The fermentation of the three drinks and their mixtures has also been studied by measuring the pH as a function of time. The pH of the sobo-orange and sobo-pineapple mixtures increase with time and increase in the orange juice or pineapple juice content of each mixture, although the change in pH with time of the sobo-orange mixtures were higher than those of the sobo-pineapple mixtures. The variation of pH with time is a measure of the stability or shelf-life of each mixture. Thus the combination of the results of titratable acidity, nutritive value and shelf-life showed that the combination of sobo with orange juice or pineapple juice is superior to the sobo, orange juice or pineapple juice alone.