ISSN:
1573-0972
Keywords:
Cereals
;
enteropathogens
;
lactic acid fermentation
;
weaning foods
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract Survival of Bacillus cereus, Campylobacter jejuni, enterotoxigenic Escherichia coli, Salmonella typhimurium and Shigella flexneri during lactic acid fermentation of cereal gruels prepared from low-tannin (white) and high-tannin (red) sorghum varieties was studied. A previously fermented gruel (starter culture, SC) recycled daily or stored for 7, 14 or 28 days, germinated cereal flour (power flour, PF), or a combination of PF and SC (PF+SC) were used as starters. At 24 h, the pH of all gruels with added starter was ≤4; the pH in control gruels without starter was ≥5.2. pH decrease was significantly faster in gruels made with PF+SC than with either PF or SC alone (P〈0.05). A daily recycled SC resulted in a significantly faster decrease in pH (P〈0.05) than SC stored for more than 7 days. Acid production was correlated with pH decrease (r=−0.94; P〈0.01). In control gruels, the enteropathogens remained at the inoculation level or increased in number. Their growth was inhibited within 24 to 48 h in the fermented gruels, in the order: Bacillus 〉 Campylobacter 〉 Escherichia coli 〉 Salmonella 〉 Shigella. The inhibition rate was significantly faster in fermenting gruel with PF+SC (P〈0.05) than in gruel with PF or SC alone and correlated with pH development (r=0.71; P〈0.01). Both white and red sorghum gruels gave similar results. Using PF+SC as a starter resulted in a faster decrease in pH as well as a more rapid inhibition of enteropathogenic microorganisms. The effect is optimal if the SC is transferred daily.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00327955
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