Thesis (BS Food Technology) -- University of the Philippines Mindanao, 2011

Lactic acid fermentation using an alternative medium consisting of sago starch, MRS salts, whey (35%), wort (25%), dilluted corn steep liquor (31%) and proteose peptone (0.075%), was carried out in a 2-L and a 30-L locally fabricated fermentor. Initial results gave a yield of 48 g/L of lactic acid after 48 hours. Powdered activated carbon (PAC) was used as adsorbent for lactic acid recovery from fermentation broth produced. The adsorption and desorption processes were carried out in shake flasks and column experiments. Results from the batch adsorption experiments in shake flasks showed 87% lactic acid (or 41.7 g/L from the initial load concentration of 48 g/L) was adsorbed while 13% was eluted with 89% purity. Lactic acid was not totally adsorbed due to the reduction of the PAC capacity and because of competition of the lactic acid and the other heavier hydrocarbons in the broth. Eluents such as 0.5 M HC1. 1 M HC1, 0.5 M H2SO4 and 1 MH2SO4 were tried. Results showed that the mean lactic acid recovered of each acid eluents using 1:2 ration did not significantly differ. Similar result was obtained with 0.5M and 1M H2SO4 and 0.%M and 1M HC1 using 1:3 ratio. Moreover, the data showed that the mean for the lactic acid recovered using ultrapure water as eluent was significantly higher at 36% compared to the previous four eluents and gave 90% purity. Furthermore, fixed-bed column experiments improved lactic acid recovery at 61.6% with purity of about 90%. excellent removal of color compound and odor from the broth were also achieved.