Abstract
Soy yoghurt was prepared using soy milk as a base and banana flavour fruit juice as a supplement. Three different samples were made by blending 5% and 10% banana flavour with 95% and 90% soy yoghurt respectively and one sample from soy yoghurt only as a control. 0.05% dairy yoghurt was added to each of the samples as a starter culture and the effect of fortification of banana flavour juice on the sensory characteristics of soy milk based yoghurt was evaluated. The finding indicated that the highest score of sensory attributes was related to the sample made using 10% banana flavour and 90% soy yoghurt. Significantly different taste among other samples was observed on this product and together with the sample made using 5% banana flavour and 95% soy yoghurt, significantly different score for flavor and overall acceptability was observed.
CHAPTER ONE
INTRODUCTION
Yoghurt is a dairy production that has more profits than milk. Digestive system in some of people has an allergy to lactose (sugar of milk), but lactose is transformed to lactic acid in yoghurt and dose not create allergy [8] .
On the other hand , calcium of yoghurt is absorbed in body faster than milk. Because , lactic acid of yoghurt turns calcium to solution and absorbtion . therefor , yoghurt devotes calcium to body more than milk.[8]
Yoghurt decreases event of bowel cancer remarkably and is more effective in absorbing minerals , proteins and vitamins of group bue to containing biological adequate conditions.the measurement of vitamines and salts in yoghurt is more than milk in the same volume , because dry matter of yoghurt is more than milk.yoghurt contains vitamins of B,C,A,D,E and all ingredients and features of milk.yoghurt strengthen abdomen and helps digestion of food and relax nerves due to containing vitamin B [1,2]
Experts recommend to use of yoghurt with antibiotics because the majority of antibiotics are fatal for profit bacteria of digestive system and results in disorder in it.
Based on investigations, the death of these bacteria can create high or medium dysentery.
Yoghurt can help to back to natural conditions.it has been recommended that patients use at least 250 ml of yoghurt in their daily dietary when they use antibiotics more than two weeks.since both yoghurt and banana have high nutrition facts , the production of fruity yoghurt with banana flavor has been noticed [3] .
Soymilk is milk produced from soybeans. Soybeans are generally considered to be a source of complete protein. A complete protein is one that contains significant amount of all the essential amino acids that must be provided to the human body because of the body’s inability to synthesize them. For this reason, soy is a good source of protein, amongst many others, for many vegetarians and vegans or for people who cannot afford milk and meat, since it is the least expensive source of dietary protein. The gold standard for measuring protein quality, since 1990, is the Protein Digestibility Corrected Amino Acid Score (PDCAAS) and by this criterion soy protein is the nutritional equivalent of meat and eggs for human growth and health. Soybean protein isolate has a biological value of 74, whole soybeans 96, soybean milk 91, and eggs 97 [5] . The increasing concern about fat and cholesterol content of animal milk is another factor promoting the selection of vegetable substitute for animal milk. Unsaturated fatty acid in the diet is recommended to reduce the incidence of cardiovascular disease [6] . Consumption of vegetable milk may also be beneficial in cases of lactose intolerance.
Efforts have been devoted to exploiting soybean and soybean products for the manufacture of palatable food products [7] . Products obtainable from soymilk include soy yoghurt, soy cheese, soy ice cream and the likes. Enrichment of cereal-based traditional weaning food by complementing with soybean tempeh has been reported [8] . These attributes have been reported to make soybean potentially an excellent food crop for the protein deficient countries of the world [9] [10] .
STATEMENT OF PROBLEM
The demand for fruity yoghurt with different flavors is developing. Adding fruit juice decreases viscosity and the rate of acid enhancing , but increases whey separation.the structure of fruity yoghurt can be improve by using stabilizing agents such as starches , gelatine and pectin.[(4]
Adding difference fruit juices to yoghurt increases some minerals such as Mg ,Zn ,Fe ,Cu, and else in it [5]
Although yoghurt is a relatively unprocessed food, fruit flavored yoghurt contains fruit that has been thoroughly heat treated.this is required because the fruit must contain extremely low levels(< 1 cfu /g) of yeasts prior to addition to the yoghurt.if this condition is not met , shelf life diminishes rapidly , due mainly to the growth of yeasts such as candida famat and kluy veromyces marxianus, which are capable of grow th at refrigeration temperatures , and can utilize the proteins , organic acids , and carbohydrates in yoghurt. [6]
In total , the main pre materials for production of fruity yoghurt contain milk that is turned to yoghurt and needs specific experiments and the other is fruit that selection of its type is with some process .besides , additives like powder milk, sugar ,stabilizer (pectin and starch)are added to the production. [7]
OBJECTIVE OF STUDY
General Objective
The general objective of this study is to produce A Banana Flavored Soy Yoghurt.
Specific Objectives
To develop soy milk
To develop soy-yoghurt
To develop a flavoured soy yoghurt
Significance of the Study
The output of this research will be used to show the possibility of soy yoghurt production using locally fermented dairy yoghurt starter culture. Consequently, low income society will enjoy the benefits by consuming nutritious and low cost soy-based yoghurt. In addition, interested professionals of Food Science and Technology will use the output of this research to cooperate and create job opportunity. Moreover, investors who want to invest on soy yoghurt production can use it and enjoy the benefits by producing fruit flavored soy yoghurt in large scale.
