Shelf-life Extension of Nigerian Traditional Bean (Vigna unguiculata) Pudding (Moinmoin) by HACCP-guided Interventions in the Preparation Process

Abstract

Background: Moinmoin is an inexpensive popular Nigerian traditional break-fast bean-pudding, which deteriorates within 24 hours of preparation due to microbial activities. The popularity is an impetus for seeking ways of extending the shelf-life. Aim: The potential of extending moinmoin shelf-life using HACCP-guided control interventions in the cooking process was therefore, investigated. Place and Duration of Study: This was undertaken in Delta State University, Abraka, Nigeria, over a period of 6 months. Study Design and Methodology: Samples were collected from 3 roadside eateries at each step of the preparation process (soaking water, bean paste, ingredients and swabs from blender, cooking pots and packaging materials) and analysed for bacteria population using Nutrient and MacConkey agar. Isolates were identified by morphological and biochemical tests while hygienic practices were assessed with structured questionnaire. Control interventions were by pasteurization, blanching of ingredients and disinfection of equipment. Results: Population of bacteria isolates varied with moinmoin preparation steps (2.5-6.4 log cfu/g/cm2/ml) with E. coli, Staphylococcus, Bacillus, Pseudomonas, Klebsiella, Salmonella, Enterobacter and Proteus as the constituents. Intervention measures eliminated these bacteria except Bacillus with low counts (4 cfu/g) in the bean paste. All the bacteria grew better in the bean paste than in the RTE moinmoin, which contained onion and pepper (P=0.000-0.001). Hygienic handling was poor (<50% of max. score). The addition of onion and pepper to the paste tended to retard the growth of the pasteurization-injured Bacillus sp. in shelfed RTE moinmoin for 72 h. Respondents (>50%) indication of dissatisfaction with taste, colour and aroma of shelved RTE which came after 72 h corroborated the 72-h shelf-stability. Conclusion: The HACCP-guided intervention measures eliminated all other bacteria and retarded growth of Bacillus, the only surviving deteriogen, and consequently extended shelf-life of RTE moinmoin from <24 h to 72 h.