We report here a new method termed “DRCMS” (Dried Raw Camel Milk Sample) detailing how to collect raw camel milk samples from hot and remote areas for microbiological analysis. Thirteen raw fresh camel milk samples collected from different sources including food market and a camel farm from Tamanrasset city were subject to different analysis, namely pH measurement, MA enumeration and drying test on SWFP.
Considering the pH assessment, different studies report that the value of pH in fresh raw camel milk is ranged between 6.5–6.7 (Elhosseny, Gwida, Elsherbini, Abu Samra, & Ashmawy, 2018), which is in agreement with the pH values of the following samples : M02, M03, M04 M05-S1, M05-S2, M07-S1, M07-S2 and M09. However, low pH values were recorded for M08 M011, B01-S1 and B01-S2 samples (Table. 1). It could be due to poor hygienic milking and the high microbial load (Al haj & Al Kanhal, 2010; Drici et al., 2016). Moreover, the variable log10 cfu/mL counts indicated that each raw fresh camel milk samples have diverse numbers of log10 cfu/mL at 30°C (Table. 1). The viable CFUs among the fresh raw came milk samples range from (4,30 ± 0,02) to (8,60 ± 0,11) (Table. 1), demonstrating that all raw fresh camel milk samples contained viable microbiota, which may be able to produce lactofermentation activity in fresh milk. The initial high CFUs count in the collected tow samples B01-S1 and B01-S2 from camel dairy farm seems to be linked to microbial contamination at milking level or absence of refrigeration between milking and arrival point of sale. Besides, The low pH values 6.31 and 6.33 of the tow respective samples B01-S1 and B01-S2, is consistent with high microbiota load (Drici et al., 2016). However the M02 and M06 sample exhibit the lower MA count respectively (4,30 ± 0,02) and (5,46 ± 0,15), which meet the hygienic status regarding the MA criterion as a main partial index of raw milk quality (Freitas et al., 2009). As well, the microbiota growth capabilities was possible for all DRCMS from 11 raw camel milk samples. In fact resuscitation example of microbiota stored on SWFP is displayed in Fig. 2-C-Step5, which shows that active microbial communities are able to keep their cultural characteristics and can be recovered from the sterile Whatman paper. This result supports our hypothesis that DRCMS is an effective technique to store camel milk and preserve the microbiota that can be later recovered from the sterile dried Whatman paper. It will be useful technique for microorganisms storage to identify benefits bacteria as well foodborne microbes. Even though the CFU count from suspended Whatman paper seems lower than fresh samples, this could be due to desiccation. However, the results indicate microbial culture can be restored up to 3 days of storage on Whatman paper (Table 1). On the other hand, the data suggests that there was no microbiota unit count variability between raw camel milk at fresh state and after 0, 1, 2 or 3 days storage on SWFP for 85% of raw milk samples (Table 1).
Variability of gel type among the thirteen samples, indicates the possibility of having different microbial composition in different samples. It is possible to expect microbiota composition from obtained gel type after Lactofermentation test (Laithier et al., 2012; Lemire, 2007; Raynaud et al., 2007). In fact, gel type “T1” (Fig. 1-B) support the presence of benefits microflora which mostly contain Lactic Acid Bacteria“LAB” known as Generally Recognized As Safe “GRAS” status. Is well known, that typical LAB, contain a diversity of species belonging to genera of Lactobacillus, Lactococcus, streptococcus, Pediococcus, Oenococcus, Enterococcus, Leuconostoc and weissella which are food-grade microorganisms (Ringø et al., 2018). Its paly an essential role in the fermentation of vegetable, animal raw materials, and produce “Lactic Acid” as the majority end product from the fermentation of carbohydrate (Carr, Chill, & Maida, 2002). However gel type “T2; T3 and T4 are recognized harbouring spoilage (coliforms, Pseudomonas or) or/and potentially pathogenic microflora (E. coli, coagulase-positive staphylococci, salmonella, Listeria monocytogenes) (Laithier et al., 2012). In addition it was possible to extract DNA from the DRCMS containing camel milk microbiota and PCR reactions were performed.