Microbiological Quality of Cowpea Paste Used to Prepare Nigerian Akara

Abstract

AJ3STRACTCowpea (figna unguicuZutu) paste used to prepare akara was collected from three Nigerian marketplaces and analyzed to determine populations and predominant types of bacteria, yeasts, and molds. Total aerobic microbial populaiions were initially high (106-10n/g) and increased after 12 hr incubation at 30-32°C to ca. log/g. Initial coliform populations were 102-104/g and decreased slightly.ietween 6 hr and 12 hr; yeast/mold populations remained constant at W-105/g. The average initial pH of 6.0 declined to 5.1 and 4.5 after 6 hr and 12 hr incubation, respectively. Predominant bacteria consisted of Enterobatter, Klebsiella, and Lactobacillus species; Candida species and AspergilZus niger were the predominant fungi isolated from the pastes.Samples (1.0 mL) were dispensed onto the surfaces of standard method (SM), violet red bile (VRB) and prototype yeast/mold (YM) Petrifilm plates (3 M Company, St. Paul, MN) initially and after 6 hr and 12 hr to determine populations/g of total aerobic microorganisms, coliforms and yeasts?mblds, respectively. Petrifilm plates were incubated at 30-32°C for 24 hr (SM and' VRB olatesl or 72 hr NM olatesl before colonies were cdunted. The temieratuie and pH (;H paier) ok pastes were determined at each sampling time.Petrifilm plates were wrapped in plastic, sealed and maintained at 23-26°C during a 22-hr transport period to our laboratory where they were stored at 21°C until colonies were picked for identification. Colonies were picked from the Petrifilm plates within 6 days of the initial day of inoculation and cultured on various growth me&a. Trypticase SOY agar (TSA. Difco. Detroit. MI) was utilized as a nonselective

Safety Challenges Associated with Traditional Foods of West Africa

“…(48,49) This organism survives processing, pasteurization conditions, and postprocessing conditions in infant formula and milk powder. (58,59) Bulgarelli et al (21) isolated C. sakazakii from cowpea paste meant for akara production in Nigeria, whereas Coulin et al (60) detected C. sakazakii from attieke, a traditional fermented cassava product in Ghana. Mensah et al (61) had earlier described the presence of this bacterium in street foods in Ghana.…”

“…flexneri to survive and grow in such conditions in traditional acidic fermented foods has been reported. (21) …”

“…A study on microbial safety quality of traditional nonfermented food in W. Africa showed that ubiquitous bacterium, Cronobacter sakazaki, was isolated from traditional nonfermented Nigerian akara. (21) The incidence of infantile diarrhea as a result of C. sakazaki infection could be severe. This foodborne pathogen survives processing treatments and must have originated from unhygienic handling and use of contaminated water for processing.…”

Sensory properties of akara (fried cowpea paste) prepared from paste stored at low storage temperatures

“…The paste once prepared could sometimes be left to stand at ambient conditions for several hours before it is prepared for consumption. This practice has resulted in akara vendors discarding unused paste after some hours of holding due to souring (Bulgarelli et al, 1988). With such long holding hours at relatively high ambient temperature and humidity, the paste would support high populations of several types of microorganisms.…”

Whipping and Lowering of Moisture Content To Reduce Cowpea Paste Souring Rate

“…The souring process is brought about by the anaerobic fermentative activity of lactic acid bacteria (Bulgarelli et al, 1988;Chavan & Kadam, 1989). Holding of the paste under ambient conditions could cause rapid proliferation of many microbial species that could influence the chemical and functional properties of the paste (McWatters, 1983).…”