CHAPTER ONE

INTRODUCTION
1.1 BACKGROUND OF THE STUDY

Yoghurt is a fermented milk product, produced with a yoghurt starter culture which is a mixed culture of streptococcus thermophilus and lactobacillus bulgaricus in a 1:1 ratio. S thermophilus enjoys a faster growth than L hulgricus.  It adds flavours and aroma to the yoghurt, though both organisms in association produces lactic acid but acetaldehyde and dimethyl propanol, the chief favour component of yoghurt is produced by L bulgaricus.

Every producer be it private or public more especially profit making has objectives in mind to achieve, some of which are to sue a process/method that is convenient and hygienic for himself, workers and to the final consumer of his product (yoghurt). Lack of research has landed many producers of yoghurt into confusion on the method and process of producing yoghurt, thereby producing a substandard yoghurt which may not meet the taste of the consumers like “mouth feel and appearance”.  They need to know the various methods and different materials that are used in yoghurt which will improve its general quality. Moreover whichever method that is chosen must be economical in all aspect, so that the producers will have some profit after calculating the cost and the products retail price will not be too much for the average consumer to afford.

1.2 AIMS AND OBJECTIVES OF THE STUDY

          Many producers of yoghurt are confused on the methods and process of producing yoghurt, consequently, producing substandard yoghurt which may not meet the taste of the consumer. However, this research work is aimed at developing appropriate process of producing yoghurts. The research work is also aimed at solving the problems of different methods of processing yoghurt. Also, it is aimed at assessing the economic aspect of the different methods of producing yoghurt which are economical in terms of the cost.

1.3 SIGNIFICANCE OF THE STUDY

          This project is important to all producers, students and researchers in food based discipline as it studies and assess different methods adopted in yoghurt production.  It will help students and researchers to know the various materials used in the production of yoghurt which will improve its general quality. This research work will also provide suitable methods for the production of yoghurt, which will be economical (to cover the cost of materials used for production).

1.4 STATEMENT OF THE PROBLEMS

          Yoghurt production is very expensive and most of its methods are tedious. Most yoghurt produced, cannot keep for a long time due to the inability of the producers to get the right materials fro the production of yoghurt. The PH at which yoghurt is produced is also another problem, because if the right PH is not gotten and controlled and if it exceeds that PH level the taste will be too acidic and will not give that sour taste peculiar to yoghurt.  Also PH above four (4) favours the growth of some microorganism such as coliforms, staphylococci, pseudomonas etc.  These microorganisms can contaminate the milk, thereby making unfit for the consumers.  In food processing we have garbage in garbage out which means that if you starts with a pour raw material you are equally coming out with pour finished product.

1.5     LIMITATIONS OF THE STUDY

This project is limited in scope to the various methods of producing yoghurt; process development and economics implication of these methods, however, there are limiting factors such as money, time and the unwillingness of some manufacturers of yoghurt to reveal their process method and financial factors of the product.

          Money is required to purchase the materials for the production of yoghurt. Time is also a problem, as it is needed to carryout the research work or project.