Microbiological Quality of Milk from Small Processing Units in Senegal

Abstract

Consumption of milk and dairy products has increased significantly in Senegal in the last decade, and a large part of the local production comes from small processing units spread all over the country. We collected 85 bulk-tank milk samples from 68 smallholder dairy farms throughout the territory. Microbiological quality of milk samples was analyzed according to the official standards. Further, raw milk and pasteurized milk were screened for Mycobacterium bovis, Coxiella burnetii, and anti-Brucella abortus antibodies. Ninety-three percent of pasteurized milk samples, 92% of raw milk samples, and 81% of sour milk samples failed to meet official standards. Pathogens detected in milk were C. burnetii (6/41, 15%), which seems to be endemic in Senegal, coagulase-positive staphylococci (18/70, 26%), and Salmonella Johannesburg in one sample. Further analysis of coagulase-positive staphylococci isolated from samples containing more than 10(4) colony-forming units per gram showed the presence of enterotoxigenic strains in 9 of the 10 samples. These results confirm the poor microbiological quality of milk produced by small units in Senegal, especially and surprisingly of pasteurized milk. This highlights the need to implement good hygiene practices, particularly in the postpasteurization process, and an effective monitoring throughout the production and delivery chain.

Food safety management systems performance in African food processing companies: a review of deficiencies and possible improvement strategies

“…For example, spontaneous and uncontrolled fermentation is a common practice for traditional fermented products, including dairy products and togwa , a lactic acid‐fermented gruel . Moreover, high microbiological counts (including Pseudomonas spp., total aerobic counts and coliforms) were found in commercially pasteurized milk in Botswana, Senegal and Ethiopia . Excessive counts of coliforms (3.44 log CFU mL −1 ), yeast (3.11 log CFU mL −1 ) and molds (4.16 log CFU mL −1 ) have been reported in yogurt in Uganda .…”

“…With respect to intervention processes (processes aimed at reducing microbial contamination to acceptable levels) such as pasteurization, fermentation and drying, studies showed inadequate and uncontrolled processes . For example, spontaneous and uncontrolled fermentation is a common practice for traditional fermented products, including dairy products and togwa , a lactic acid‐fermented gruel .…”

Quality and Safety of Bovine Raw Milk: Present Challenges and Technological Solutions

“…Producers, mainly organised as small holders, suffer to meet the challenge of producing raw milk of sufficient microbiological quality. A study reported that over 75% of raw milk samples exhibited excessive bacterial counts, with an average of 4.5 × 10 7 cfu/g of raw milk; the poor microbiological quality of raw milk at the farm level was due to contaminations resulting from a lack of adequate equipment and facilities, of good hygiene practices along the collection and processing steps [14].…”

Microbiological quality of pasteurized milk on expiration date in Tehran, Iran

“…Various outbreaks of foodborne illnesses associated with the consumption of pasteurized milk or pasteurized dairy products have been reported previously (CDC, 2008;Schmid et al, 2009;Koch et al, 2010;Jackson et al, 2011). Although many studies have been conducted on the microbiological quality of pasteurized milk in different parts of the world (Ranieri and Boor, 2009;Breurec et al, 2010;Silva et al, 2010;Anderson et al, 2011;Martin et al, 2012;Belli et al, 2013;Quigley et al, 2013;Kamana et al, 2014), only a few studies, with limited numbers of samples and regions, have been reported about microbial contamination of pasteurized milk in Iran (Fadaei et al, 2008;Vahedi et al, 2013;Teymori et al, 2014;Koushki and Koohy Kamaly, 2016). The aim of this study was to evaluate the microbiological quality of pasteurized milk sold in Tehran on its expiration date.…”