A survey based on thirty units of kilishi manufacturing units "kilishierie" was conducted in the three regional cities of North Cameroon (Ngaoundéré, Garua and Marua), in order to characterize the actors, their organization, their technology, their building and perception of kilishi quality (a dried meat or smoked meat sliced, seasoned with a cocktail of ingredients and roasted or not over wood fire). It appeared from this survey that, the technical system was 77% dominated by the Hausa, 47% were cameroonians, 27% nigerans and 3% nigerians. The organization was essentially tribal with very few relations between the actors of the different production units. The production technology varies from one producer to another and according to the spaces, mainly in the technique of unwinding, drying and the formulation of seasoning for coating the slices of dried meat. The meat used for kilishi production came from 61% of Goudali zebu, 30% Bororo zebu and 9% Fulani zebu. Of the 105 carcass muscles, only 09 muscles (slice tender, sirloin steak, walnut lodge, round of lodging, fillet, rump, scoter, slice and chuck) were used and implied the frenetic research for noble meat. The investigation revealed two types of unwinding meat, the 15cmx5cmx5cm and along the muscle and 2 drying modes (drying in the sun and dry-smoking), which resulting in a dozen of types of kilishi. The construction and perception of quality by actors at the level of all unit operations were identified. The main limiting factors of the technical system were related to the variability of the quality and the availability of meat, the technical constraint of the unwinding techniques, the practice of uncontrolled drying and packaging. The major consequences of these factors are the low hygienic value of the product and its variability. The control of these factors is therefore an important issue for the improvement of this technical system. The annual production was estimated at about 132.5 tons of kilishi for a cash value of about 1.650 000 000 FCFA.

This work has been led in view to find the influence of sublethal heat (45°C, 50°C, 60°C) on acid resistance of B. subtilis NCTC 3610 and B. stearothermophilus CNCH 5781 spores. Firstly, we have submitted Bacillus spores to 0.4% acetic acid pH 4.5 during the times of 1, 2 and 3 hours. Then another spores group were preheated at various sublethal temperatures, before be treated with acetic acid. The effect of acetic acid before and after preheat was evaluated by the culture of treated spores on agar medium and the number of colony obtained was compared with that of control culture (neither treated with heat nor acid) and control A culture (only treated with acid). We found that acetic acid was effective on the twice Bacillus spores with more effect on B. stearothermophilus CNCH 5781 spores. Furthermore we have noticed a significant increasing in percentages of recovery of colonies obtained from preheated and acid treated spores compared to those of control and control A cultures. This increase of recovery percentages could be demonstrated the manifestation of a "heat-induced acid resistance" phenomenon. Yet, this phenomenon was more accentuated for preheatings at 50 and 60°C during 3 and 2 hours, respectively for B. subtilis and B. stearothermophilus spores. This study suggest that sublethal heats could be play major role in protection of microorganisms to chemicals