Figure 1. Production process of BE/BS. METHODOLOGY Indigenous Fermented Milks from some Regions of Cameroon and Chad : Production processes, Utilizations and Challenges. Mbawala Augustin 1, *, Koussou Mian-Oudanang 2 , Mouafo Tene Hippolyte 1,4 , Tchougang Mangaptche Hervé 1 , Tchakouani Yamagueu Galvany Franck 1 and Ramona Suharoschi 3 1 Department Food Sciences and Nutrition, National School of Agro-Industrial Sciences, University of Ngaoundere, Cameroon. 2 IRED of N’Djamena, Chad. 3 Food Industry and Science Department, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania. 4 Centre for Research on Food and Nutrition, Institute of Medical Research and Medicinal Plants Studies, P.O. Box 6163 Yaounde, Cameroon. * Corresponding author E-mail address : mbawalaa@yahoo.fr INTRODUCTION CONCLUSIONS Figure 4. Some advantages and potential applications in food industries of BE/BS produced by lactobacilli (Generally recognized as safe (GRAS) status) isolated from a Cameroonian indigenous fermented milk (Pendidam) highly consumed because of its health benefits (Mouafo et al. (2018-2020), Fookao et al. (2022), etc.). The production yields of BE/BS range from 2.1 to 4.2 g/L. The main strains of BE/BS-producing and effective LABs (Oil spreading test (OST) on strain culture Cell free supernatants (CFS)) isolated from Pendidam belong to the genus Lactobacillus. The BE/BS extracted from the CFS by bio-ethanol (bio-solvent) precipitation and produced by lactobacilli (GRAS status) isolated from Pendidam possess interesting bioemulsifying properties that improve the stability of emulsions with substrates showing their potential applications in food industries and in maintaining human health. Fermentation is a biotechnological process used all over the world since ancient times to produce indigenous fermented foods and alcoholic beverages. The demand of traditional fermented foods by consumers is increased due to their numerous health benefits and important nutritional values. Lactic acid bacteria (LABs) have been reported as the main actors of the fermentation process of indigenous fermented milks. During fermentation, LABs including the genus Lactobacillus produce metabolites such as organic acids, bacteriocins, biosurfactants, etc., that have antimicrobial activity, thus prolong the shelf life of foods (Mouafo et al., 2018a; 2018b; 2020, Fookao et al., 2022). The “researched” properties of each fermented milk depend on the quality of raw materials, ingredients and the technological process used during its production. The aim of the present study is to establish after exploiting some published and experimental data : the technological processes, the utilizations, the potential properties and some related challenges of indigenous fermented milks produced in some regions of Cameroon and Chad. MRS and M17 broths; MRS and M17 agars Gram staining; Biochemical test + API Gallery 50 CHL Oil spreading test (OST) + Production of BE/BS Isolation and Identification of Lactic Acid Bacteria (LABs) strains producing bioemulsifiers/biosurfactants (BE/BS) Figure 2 . Production processes : (A) Pendidam in Cameroon; (B) Rouaba in Chad. REFERENCES MOUAFO, T.H., MBAWALA, A., & NDJOUENKEU, R. Effect of Different Carbon Sources on Biosurfactants’ Production by Three Strains of Lactobacillus spp. Biomed Research International (2018a), 1-16. https://doi.org/doi.org/10.1155/2018/5034783 Research. MOUAFO T. H., MBAWALA A., TCHOUGANG M. H., NDJOUENKEU R. and SOMASHEKAR D. Application of response surface methodology to improve the production of antimicrobial biosurfactants by Lactobacillus paracasei subsp. tolerans N2 using sugar cane molasses as substrate. Bioresources & Bioprocessing (2018b) 5 (48): 1-16. https ://doi.org/10.1186/s40643-018-0234-4. MOUAFO, H. T., MBAWALA, A., TANAJI, K., SOMASHEKAR, D., & NDJOUENKEU, R. Improvement of the shelf life of raw ground goat meat by using biosurfactants produced by lactobacilli strains as biopreservatives. LWT - Food Science and Technology (2020), 133: 1-8, 110071. https ://doi.org/10.1016/j.lwt.2020.110071 ARMELLE NEUYAMNE FOOKAO, AUGUSTIN MBAWALA, NADÈGE DONKENG NGANOU, RICHARD MARCEL NGUIMBOU, HIPPOLYTE TENE MOUAFO. Improvement of the texture and dough stability of milk bread using bioemulsifiers/biosurfactants produced by lactobacilli isolated from an indigenous fermented milk (pendidam). LWT- Food Science and Technology (2022) 163: 1-9. https ://doi.org/10.1016/j.lwt.2022.113609 RESULTS AND DISCUSSION Centrifugation Fermentation Centrifugation Ethanol precipitation (4°C overnight) LAB + Broth BE/BS Preliminary characterization : chemical nature of BE/BS Production yield Emulsification Index (E24) Stability tests: Extreme pH and T°C, variation of salinity (NaCl) Chemical analysis and Thin Layer Chromatography (TLC) Oil spreading test (OST) on Cell free supernatant (CFS) Screening of indigenous fermented milks and Sampling Cameroon Chad Figure 3. Stability of emulsions of refined palm oil + BE/BS after 48 hours. Results of chemical analysis and TLC showed that the chemical nature of the BE/BS produced could be a glycolipopeptide. The indigenous fermented milks in the localities investigated were represented by four types : Pendidam and Kindirmou in Cameroon; Rouaba and Rayeb in Chad. They are all produced by fermentation of raw fresh milk from cow origin and used mainly for feeding and therapeutic purposes. A B The BE/BS produced were stable at extreme pH (2 to 12), extreme temperatures (25 to 121°C) and varied salinity (0 to 50% NaCl (w/v)). GREAT CHALLENGES ABOUT HEALTH CARE Utilizations of GRAS BE/BS to fight against the : - Covid-19, AIDS, Influenza, Hepatitis B and C viruses… via capsules (oral medication). - Myocardial Infarction (MI), Cerebro-Vascular Accident (CVA) via coronary angiography techniques. Raw fresh milk Pendidam Sieving Boiling (or pasteurization) Skimming Cooling (room temperature) Inoculation Homogenization Incubation (room temperature, 48hrs) Skimming Particles & Solid matters Vapours Fatty matters Old Pendidam Fatty matters Hot water & firewood Raw fresh milk Rouaba Filtration Boiling (or pasteurization) Cooling (room temperature) Rinsing and smoking (empty buxa) Inoculation of empty buxa Adding cooled milk Incubation (room temperature, 1 night) Churning Particles & Solid matters Vapours Old Rouaba Butter Water & firewood debris