RECYCLING OF BAKERY WASTES USING AN AMYLOLYTIC LACTIC-ACID BACTERIUM

Production of lactic acid from discarded bread by using an amylolytic lactic acid bacterium Lactobacillus amylovorus, was investigated to re cycle bakery wastes. Addition of 2.0% yeast extract in the medium cont aining 3.58% bread crust caused maximum acid production. The stimulati on of lactic acid production by less expensive materials such as corn steep liquor; defatted soybean powder rice bran and wheat bran at addi tional levels of 2.0% was also observed but limited. Acid production i n the medium supplemented with 2.0% coin steep liquor was enhanced by the further addition of 2.0% defatted soybean powder and reached the l evels comparable to medium containing 1.4% yeast extract. In the mediu m supplemented with 2.0% corn steep liquor and 2.0% defatted soybean p owder 47.2% of total sugars was converted to DL-lactic acid in 72 h un der static incubation. When the baking test was carried out, the bread made with the addition of the culture filtrate was significantly (P < 0.05) preferred over those with and without addition of commercial fe rmented seasoning with respect to taste and overall acceptability. (C) 1997 Elsevier Science Ltd.