Optimization of Protein Extraction from Arachis hypogaea L. and Cucumeropsis mannii Naud. Seeds for Use as Natural Coagulants in Surface Water Clarification

The aim of this study was to improve the quality of protein extracts from Cucumeropsis mannii Naud. and Arachis hypogaea L. The evolution of protein content and microbiological quality of aqueous extracts of A. hypogaea, C. mannii and M. oleifera seed powders were monitored over time during protein extraction. The protein contents of the extracts subjected to decantation and those subjected to centrifugation were determined by the Kjeldahl method. The microbiological quality of the different aqueous extracts was evaluated according to the standards NF EN ISO 7932, NF V 08-059 and NF EN ISO 4833-1. The results obtained show protein contents of 40.6 % for A. hypogaea, 25.4 % for C. mannii and 36.5 % for M. oleifera, after 24 h of decantation. The protein contents of the centrifuged aqueous extracts were higher and 55.9%, 36.7% and 37.6% for A. hypogaea, C. mannii and M. oleifera extracts respectively. The results of the microbiological analysis showed that the aqueous extracts of M. oleifera contain little microbial load. Significant growth of aerobic flora and Bacillus cereus was observed in the decanted extracts of C. mannii and A. hypogaea from 4 h to 24 h of decantation. Extracts obtained by centrifugation have a lower microbial load, because the treatment time was shorter. The aqueous protein extracts of A. hypogaea and C. mannii seed powders obtained by centrifugation were of better quality than those obtained by decantation, because they have higher protein contents and lower microbial loads. The water solubility of A. hypogaea and C. mannii seed proteins was also studied on protein suspensions at 2% at pH 3, 4, 5, 6, 7 and 8. The results obtained showed that adjusting the pH to 7 and 8 could improve the degree of protein extraction for A. hypogaea and C. mannii seeds.

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Microbial quality of beef and hygiene practices in small and medium slaughterhouses and butcheries in Uganda

10.21203/rs.3.rs-48693/v1 ◽

2020 ◽

Author(s):

Juliet Kyayesimira ◽

Wangalwa Rapheal ◽

Grace Kagoro Rugunda ◽

Lejju Julius Bunny ◽

Morgan Andama ◽

...

Keyword(s):

Microbial Contamination ◽

Microbiological Quality ◽

Microbial Load ◽

Microbial Quality ◽

E Coli ◽

Hygiene Practices ◽

Safe Level ◽

Microbiological Methods ◽

Beef Carcass

Abstract Background If hygiene practices along the beef processing nodes at small and medium enterprise (SME) slaughter houses and butcheries are not observed, they may pose a health risk due to microbial contamination. In SME slaughterhouses and butcheries, the risk may be higher due to transmission of foodborne pathogens. This study determined the hygienic practices and microbial quality risk among meat handlers (MH) in SME slaughterhouses and butcheries. Methods Assessment of microbiological quality of beef was carried out at slaughter houses and butcher shops in the districts of Western, Central and Eastern regions of Uganda. A cross sectional study was conducted from June 2017 to January 2018 using observation checklists to record unhygienic practices among the various actors. Microbial load at slaughter and butchery was determined from a total of 317 swab samples collected from carcass, tools, protective clothing and hands of meat handlers. The microbiological quality of beef was evaluated using standard microbiological methods. The samples were inoculated into differential and selective media. Results Butcheries had the highest microbial load on beef carcass ranging from 4.76 log 10 cfu/cm 2 to 7.90 log 10 cfu/cm 2 Total Viable Counts (TVC) while Total Coliform Counts (TCC) ranged from 1.42 log 10 cfu/cm 2 to 3.05 log 10 cfu/cm 2 , E. coli ranged from 0.68 log 10 cfu/cm 2 to 1.06 log 10 cfu/cm 2 and Staphylococcus aureus ranged from 3.25 log 10 cfu/cm 2 to 4.84 log 10 cfu/cm 2 . Salmonella was absent in all the samples analysed. Results of overall microbial quality of beef in Uganda indicated that only TCC (1.60±0.26 log 10 cfu/cm 2 ) of the beef carcass samples at slaughter houses was not significantly above the safe level (p = 0.693). Overall microbial load (TVC, TCC, E. coli and S. aureus ) at butcheries were significantly (p < 0.05) above the safe level. Butcheries of Mbale district had the highest percentage (70%) of beef carcass samples above the TCC safe levels whereas butcheries of Mbarara district had the highest percentage (40%) of beef carcass samples above the E. coli safe levels. TVC from hands and clothes at butchery across the three study districts varied significantly (p=0.007) with the highest counts (7.23 log 10 cfu/cm 2 ) recorded from personnel clothes and lowest (5.46 log 10 cfu/cm 2 ) recorded from hands. On the other hand, swab samples picked from chopping board and working table at the butchery did not show significant variation in TVC, TCC, E. coli and S. aureus microbial loads across the three study districts. Conclusion Hygienic handling of carcasses after slaughter is critical in preventing contamination and ensuring meat safety in informal meat trading sectors in Uganda. Handling practices of beef at Ugandan slaughterhouses and butcheries are not hygienic hence not up to standard and they contribute to microbial contamination of beef posing a risk to consumers. The distribution stage is the most critical period, during which the quality of meat can easily be compromised.

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