Microbial counts and invert sugars in juice extracts from stored tubers of Cyperus esculentus Linn. (earth almond).
The microbial populations and the levels of invert sugars in juice extracts from healthy tubers of Cyperus esculentus L. stored at 10, 20, 30 and 40 degrees C were determined. Bacterial counts increased with time and attained the peak on the 25th and 35th d at 40 and 30 degrees C respectively. Similar trends were obtained for the yeasts, but the peak counts were recorded on the 20th and 35th d at 40 and 30 degrees C respectively. At 10 and 20 degrees C, the counts, both for bacteria and yeasts increased throughout the 40-d period. Invert sugar levels increased throughout the investigation period at all the tested temperatures. Highest levels were recorded at about 30 and 40 degrees C while the lowest levels were obtained at 10 degrees C. Of the seven bacteria and five yeasts tested, only Saccharomyces rouxii, S. cerevisiae, Schizosaccharomyces sp., Pseudomonas chlororaphis, P. fluorescens and Bacillus subtilis brought about significant hydrolysis of sucrose in vitro. Results on the microbial populations and levels of invert sugars in raw juice extracts suggest that yeasts could possibly play a greater role than bacteria in the hydrolysis of sucrose in vivo.
Adebajo
L O
LO
Department of Biological Sciences, Ogun State University, Ago-Iwoye, Nigeria.
D001419:Bacteria / Q000302:isolation & purification; D002241:Carbohydrates / Q000032:analysis*; D005516:Food Microbiology; D005519:Food Preservation; D006868:Hydrolysis; D009549:Nigeria; D010936:Plant Extracts / Q000032:analysis; D013395:Sucrose / Q000032:analysis; D013696:Temperature; D014675:Vegetables / Q000737:chemistry* / Q000382:microbiology; D015003:Yeasts / Q000302:isolation & purification
D002241:Carbohydrates; D010936:Plant Extracts; D013395:Sucrose