Abstract

Guava (Psidium guajava) pulp was fermented with Lactobacillus plantarum WU-P19 to a product rich in microbially produced vitamin B12 and conjugated linoleic acid. Different initial sucrose levels were tested in the pulp in different fermentations. The 36-hr fermented material had a pH of 3.3–3.4, a lactic acid content of 7.6–8.2 g/L, and a viable L. plantarum count of 10^8.51–10^8.56 cells/ml. The fermented pulp was used to make a novel food product, the guava gummy jelly. The guava gummy jelly formulation that was most accepted by a panel of tasters, comprised of 100 g (fresh weight) of fermented guava pulp, 20 g of sucrose, 11 g of glucose syrup, 6 g of gelatin and 0.5 g of citric acid. A 1-g portion of this tasty product could fully meet the daily requirements of vitamin B12, an essential nutrient that is deficient in many diets. Practical applications: Vitamin B12 deficiency in certain diets can be alleviated through consumption of the fermented food product produced here. The fermented product offers a high-value application of waste pulp of commercial guava juice production.