FACULTY OF AGRONOMIC SCIENCES
Department of Chemistry and Agricultural Industries

By

Jennifer BIRALI MW AMINI
Thesis presented for the purpose of obtaining the degree of Doctor of Agronomic and Environmental Sciences

Composition of the jury members:
1. President
Professor KINKELA SAVY Charles 1 UNIKIN FAC AGRONOMY
2. Secretary
Professor KIZUNGU VUMILIA Roger 1 UNIKIN FAC AGRONOMY
3. Promoter
Professor SUMBU ZOLA Eric 1 UNIKIN FAC AGRONOMY
4. Co-promoter: Professor WALANGULULU MASAMBA Jean 1 UCB FAC AGRONOMY
5. Member
Professor MALUMBAMUKAYA/UNIKIN FAC SCIENCES
6. Alternate member: Professor NTUMBA KANKOLONGO 1 UNIKIN FAC SCIENCES
7. Alternate member: Professor TABA KALULU IUNIKINFAC SCIENCES

SUMMARY

CONTRIBUTION TO THE STUDY OF STABILIZATION AND STANDARDIZATION OF "MASHANZA", TRADITIONAL FRESH CHEESE FROM SOUTH KIVU "Mashanza", a cheese produced in the East of the DR Congo, considered a luxury product by the "Shi" people, has not experienced development like other traditional cheeses. Few studies have been devoted to it until now. Its short shelf life,
The multiplicity of processes and the lack of a standard constitute a constraint. The first objective of this study was to understand the ways of stabilizing the nutritional, hygienic and organoleptic quality of the product. The second objective was to contribute to laying the foundations for standardization. To do this, surveys of producers in Kabare, Kalehe, Uvira and Walungu in South Kivu and consumers of "mashanza" in the cities of Bukavu and Goma, as well as on-site tests, were carried out in order to better understand its characteristics, its manufacturing process and perceptions by consumers.
consumers and manufacturers. Five manufacturing processes were inventoried, two of which are common. The effect of pasteurization, fermentation duration, draining methods and storage (cold) on the moisture content, ash, protein, pH and lactic acidity of "mashanza" was highlighted. Despite the contamination in whey and the observed lack of good manufacturing practices, fermentation has a reducing action on the pathogenic microflora present, except for the acidophilic microflora. The manufactured "rnashanza" have an acidic pH around 3.6, which is favorable for slowing down the
rapid development of pathogenic and spoilage microorganisms. Water activity reduced to a value of less than 0.80 can strengthen the lactic acid barrier against spoilage agents. Regarding the approach towards standardization, Category 1 processes producing "mashanza" rated "Very good to good" can be submitted for validation to official bodies as standard processes. These production lines have potential for industrial development by strengthening producers in good hygiene practices and improving and identifying equipment.

Keywords: fresh cheese, mashanza, process, quality, stabilization, standardization, South Kivu.

ABSTRACT

CONTRIBUTION TO THE STABILIZATION AND STANDARDIZATION STUDY OF “MASHANZA”, TRADITIONAL FRESH CHEESE FROM SOUTH KIVU “Mashanza”, a cheese produced in Eastern DR Congo, considered a luxury product by the “Shi” people, has not been developed like other traditional cheeses. Few studies have been dedicated to it until now. Its short shelf life, the multiplicity of processes, the non-existence
of a standard, and the variable quality observed in mashanza constitutes a constraint. The first objective of this study was to understand the ways to stabilize the nutritional, hygienic and
organoleptic quality of the product. The second objective was to contribute to the establishment of the basis for standardization. To this end, surveys of producers in Kabare, Kalehe, Uvira and Walungu in South Kivu and of consumers of “mashanza”, in the cities of Bukavu and Goma as weIl as in situ tests were carried out in order to gain a better understanding of its characteristics, its manufacturing process and the perceptions of
consumers and manufacturers. Five manufacturing processes have been listed, two of which are common. The effect of pasteurization, duration of fermentation, draining methods and conservation (co Id) on the content of me sture, ash, protein, pH and lactic acidity of “mashanza”, was emphasized. Despite the contamination in the whey and the lack of good manufacturing practices observed, the fermentation has a significant reducing action on the pathogenic microflora present, except for the acidophilic microflora. The manufactured “mashanza”, have an acidic pH around 3.6 favorable to inhibit the rapid development of pathogenic and spoilage microorganisms. The activity of water reduced to a value of less than 0.80 can strengthen the barrier of lactic acidity against spoilage agents. ln terms of the standardization approach, category 1 processes producing “mashanza”, rated “very good to good” as standard processes can be submitted to official bodies for validation. These production lines have a potential of industrial development through the reinforcement of the
producers to the good practices of hygiene and the improvement and identification of the equipment.

Keywords : fresh chee se, mashanza, process, quality, stabilization, standardization, South-Kivu.