الفهرس 
List of ContentsOnly 14 pages are availabe for public view
 |  | from | 177 |  |  |
| | | from | 177 | | |
Abstract
Fruits which are added to yogurt act as prebiotics (fibers), as flavoring and coloring agents , as a source of natural antioxidants (Photochemical antioxidants) . The photochemical antioxidants such as carotenoids, flavonoids and phenols , have potential health roles in the reduction of platelet aggregation, blood pressure, cardiovascular of disease and a role in modulation of cholesterol synthesis and absorption . Moreover, fruits contain protein bound polysaccharides which may increase the levels of serum insulin, reduce the blood glucose levels and improve tolerance of glucose and hence could be developed as new anti diabetic agent.
Stirred bio-yogurt and Acidophilus milk is a very healthy food which can be more desirable and important by fortifying it with a natural source of vitamins, antioxidants and phenolic compounds. The aim of this study was to:-
• Develop a desirable healthy yogurt drinks using Graviola juice ,Pumpkin juice , Date syrup (Dibs) as anatural prebiotics and by incorporating ABT cultures.
• Studying the impact of adding different types of juices on the characteristics of yogurt drinks.
• Strengthen and raise the nutritional value of regular yogurt drinks.
• Investigate the effect of chemical composition, phenolic compounds, flavonoids , minerals, vitamins and amino acids of Graviola , Pumpkin , Date syrup (Dibs) at different concentrations 0, 5, 10, 15% on activity and viability of lactic acid bacteria , total bacterial counts, aerobic and anaerobic spore formers bacteria and E.coli.
This work aimed to evaluate the chemical composition, microbiological quality and organoleptic properties of both Acidophilus milk and stirred bio-yogurt fortified with three kinds of juices (Graviola ,Pumpkin , Dibs) from fresh buffalo´s milk and at different concentrations (0%, 5%, 10%, 15%) and (10% sugar) at (fresh, 3, 7, 14 days).
This study was conducted to determine the following points:
1. Acidity, Total solids, Moisture, Total carbohydrates, Total proteins, Fat , Ash, Crude fibers ,Some minerals content, Amino acids , Phenols and Flavonoids content and Vitamins to the three kinds of juices .
2. Acidity, Total solids, Total protein, Total carbohydrates, Fat and Ash of Acidophilus milk and stirred bio-yogurt fortified with juices at different concentrations (0,5,10,15%) for (fresh,3,7,14 days) at 7±1ºC.
3. Total bacterial count, Str. thermophillus count , Lb. bulgaricus Lb. acidophilus , Bifidobacteria counts, yeasts and moulds counts, coliform bacteria, psychrotrophic bacteria and aerobic and anaerobic bacteria at stirred bio-yogurt fortified with juices at different concentrations (5,10,15%) for (fresh,3,7,14 days) at 7±1ºC.
4. Organoleptic properties such as Flavour (45), Body and Texture (30), Appearance (15), Acidity (10) at Acidophilus milk and Stirred bio-yogurt fortified with juices at different concentrations (0,5,10,15%) for (fresh,3,7,14 days) at 7±1ºC.
5. Some healthy components like Minerals, some vitamins content , Amino acids and Total phenols and flavonoids content of 3 treatments from the most favorite treatments at sensory properties at the end of storage time.
Flavored Sweet Acidophilus milk :
1- Sweet Acidophilus milk fortified with Graviola juice.
• Mean values of Protein were increased by fortification with Graviola which was the highest in T3 comparing to the other treatments. The mean values of titratable acidity of Sweet Graviola Acidophilus milk increased significantly by the incorporation of Graviola concentrations. During storage period mean values of carbohydrates content of different treatments gradually increased by the incorporation of Graviola concentrations, the higher values were in T2. Mean values of Fat and Ash of treatments weren’t increased significantly by increasing the percentage of Graviola juice and also weren’t increased during storage till the end of storage time.
• TBC and Lb. acidophilus counts of Sweet Graviola Acidophilus milk increased by the increasing the concentration of Graviola till the end of the storage period (14 days). The counts of yeasts and molds, psychrotrophic bacteria, the Coliform bacteria counts, Aerobic and Anaerobic spore formers were not detected till the end of storage period at 7ºC ±1 for 14 days;
• In general, the most preferable fresh flavored sweet acidophilus milk was T1 (5% Graviola juice +10% Sugar) in flavor, body and texture and appearance . While control was the best at acidity evaluation.
2) Sweet Acidophilus Milk fortified with Pumpkin Juice.
• The acidity mean values were higher in the treated acidophilus pumpkin juice than the control . There were no significant differences in Ash mean values during storage, however the ash content was higher in T2 and T3 than the control and T1. The mean values of carbohydrates were increased during storage and by increasing pumpkin juice There were significant decrease in the values of protein content in all drink treatments as the storage period were proceed.
• The total viable bacterial counts of lb. acidophilus found to increase up to 14 days and up to the end of storage periods in all treatments. In addition, The counts of yeasts and molds were not detected till the end of storage period. On the other hand, the Coliform bacteria counts , Psychrotrophic bacteria , Aerobic and Anaerobic spore formers bacteria were not detected in both fresh and at all treatments till the end of storage period;
• In general the control and the treatments had higher scores when fresh time in flavor , body and texture ,appearance, and acidity than the 14 days products . In addition, T2 and T3 (5 % and 10% Pumpkin) for fresh and 14 days had the superior overall acceptability .
3. Sweet Acidophilus Milk fortified with Date Syrup (Dibs).
• The total solids, ash, fat and protein contents significantly increased (p<0.05) in all treatments during the storage periods. Mean values of Fat and Protein were increased significantly in T2 and T3 by increasing the percentage of dibs. The acidity of sweet acidophilus date syrup (dibs) milk found to increase with increasing of Dibs concentrations and during storage periods at refrigerator temperature up to 14 days.
• The total viable bacterial count was increased with increasing of Dibs concentrations in all treatments. The counts of yeasts and molds were not detected till the 14 days of storage period; On the other hand, the Coliform bacteria counts , Psychrotrophic bacteria, , Aerobic and Anaerobic spore formers were not detected in both fresh and at all treatments till the end of storage period.
• All treatments had significant higher scores when fresh in flavor , body and texture ,appearance, acidity and overall acceptability than the 14 days product . T1 and T2 (5 % and 10% Dibs) had the superior overall acceptability.
Flavored Sweet Stirred Bio-yogurt:-
1. Sweet Stirred Bio-yogurt fortified with Graviola juice:-
• T3 (15% Graviola juice + 10%sugar) was the highest values in chemical composition among treatments till the end of the storage period (14 days at7ºC).
• TBC, Lb. acidophilus , Str. thermophillus, Lb. bulgaricus, Bif. bifidum counts of control and Sweet Graviola Stirred Bio-yogurt fortified with Graviola juice with (5% -10% and 15% ), The counts were increased till 14 days of preparation in all stirred Graviola bio-yogurts. Obviously, the number of TBC , Str. thermophillus, Lb. bulgaricus, Lb. acidophilus ,Bif. bifidum in treatments were affected and increased with adding Graviola juice which simulated the strains growth initially. The counts of yeasts and molds and psychrotrophic bacteria were not detected till the 14 days of storage period; In addition, the Coliform bacteria counts, Aerobic and Anaerobic sporeformers had not detected in both fresh and at all treatments until the end of storage period.
• In general T1(5%juice+10% sugar) had the highest scores at all sensory evaluations. The overall acceptability during storage is considered reasonable for a fermented dairy product.
2. Stirred Bio-yogurt fortified with Pumpkin juice.
• Stirred bio-Yogurts supplemented with 15%pumpkin juice +10% sugar was the highest values in chemical composition among treatments at the end of storage period (14 days at 7ºc). Also mean values of protein , total solids, ash and carbohydrates were increasing by increase the percentage of pumpkin juice till the end of storage period at 7ºc .
• Total bacterial count and Lb. acidophilus, Str. thermophillus, Lb. bulgaricus, Bif. bifidum were increased by increasing percentage of pumpkin juice at 7±1°C up to 14 days . The counts of yeasts and molds were not detected till the 14 days of storage period; On the other hand, the Coliform bacteria counts, Psychrotrophic bacteria, Aerobic and Anaerobic spore formers were not detected in both fresh and at all treatments till the end of storage period14 days;
• Organoleptic properties of Sweet Pumpkin Stirred Bio-yogurt (0%,5%,10% and 15% pumpkin juice) which were acceptable till the end of storage period (14 days) at 7ºC ±1. T1(5%+10%sugar) and T2 (10%+10% sugar) were the best treatments at overall acceptability, while control was the best treatment at body and texture .
3. Stirred Bio-yogurt fortified with Date Syrup(Dibs).
• The total solids mean values significantly increased (p<0.05) in all treatments than control. On the other hand, all treatments acidity was increased during storage. Results showed higher acidity (p<0.05) for T3 (Dibs15%+10% Sugar) followed by T2 (Dibs 10% + 10% Sugar),T1 (Dibs 5%+10%Sugar) and control treatments. Also, there were significant differences (p<0.05) among total carbohydrates at different treatments during storage period ,Which was higher in T2 and T3 treatments than control.
• The total bacterial count was increased with increasing of Dibs concentrations in all treatments. Also Lb.acidophilus , Str. thermophillus, Lb. bulgaricus, Bif. bifidum counts were increased by addition of Dibs and during storage periods at refrigerator temperature up to 14 days. The counts of yeasts and molds were not detected till the 14 days of storage period; On the other hand, the Coliform bacteria counts , Psychrotrophic bacteria , Aerobic and Anaerobic sporeformers were not detected in both fresh and at all treatments till the end of storage period.
• Generally, organoleptic properties increased in all tested treatments throughout storage period. The obtained data revealed that T1(5% dibs +10% sugar) gained the highest scores in flavor , appearance, acidity and overall scores. While control was the best in body and texture evaluation.
Some Analyses for Three Treatments from The most Favorite Treatments at Sensory Properties at the end of storage period: -
1. Some vitamins content (mg/100g)
Vitamins A , K , E , D and C content were measured for control , Stirred Bio-yogurt fortified with Stirred Bio-yogurt fortified with 10% Graviola juice ,10% pumpkin juice , Stirred Bio-yogurt fortified with 10% Dibs at the end of storage (14 days).These treatments were acceptable among the panelists and also had a good amount of these vitamins higher than control till the end of storage time. T4(Stirred Bio-yogurt fortified with 10% Graviola was the highest value in vitamin A between treatments and more than control. Also,T4(Stirred Bio-yogurt fortified with 10%Graviola was the highest value in vitamin E between treatments and more than control. T2(Stirred Bio-yogurt fortified with 10%pumpkin was the highest value in vitamin D between treatments and more than control. T3( Stirred Bio-yogurt fortified with 10%Dibs was the highest value in vitamin C between treatments and more than control. Also,T3(Stirred Bio-yogurt fortified with 10%Dibs was the highest value in vitamin k between treatments and more than control.
2. Total Phenolic and Total Flavonoids compounds (mg/100g) for three treatments from the most favorite treatments at sensory properties at the end of storage period: -
The concentrations of total phenols and total flavonoids compounds (mg/100g) were measured in Stirred Bio-yogurt Fortified with 10% Graviola juice , Stirred Bio-yogurt Fortified with 10% Pumpkin juice and Stirred Bio-yogurt Fortified with 10% Dibs at (Day14) which were higher than control. T3( Stirred Bio-yogurt fortified with 10%Dibs was the highest value at total phenols results and more than control . T2(Stirred Bio-yogurt fortified with 10%pumpkin Juice was the highest value at total flavonoids results and more than control .
3. Amino Acids Composition (%) for Three treatments from the most Favorite Treatments at Sensory Properties at the end of storage period.
Concentrations of Essential and Non essential Amino acids (%) were measured in control Stirred Bio-yogurt and Stirred Bio-yogurt Fortified with 10% Graviola Juice , Stirred Bio-yogurt Fortified with 10% Pumpkin Juice and Stirred Bio-yogurt Fortified with 10% Dibs at (Day14) and these flavored treatments were higher than control. T4(Stirred Bio-yogurt fortified with 10%Graviola Juice was the highest value of total amino acids content and higher than control .Also, T3(Stirred Bio-yogurt fortified with 10%Dibs and T2(Stirred Bio-yogurt fortified with 10%pumpkin Juice were higher than control.
4. Some Minerals Content for Three treatments from the most Favorite treatments at Sensory Properties at the end of storage period.
Some minerals content (mg/1000g) were measured in control Stirred Bio-yogurt and Stirred Bio-yogurt Fortified with 10% Graviola Juice, Stirred Bio-yogurt Fortified with 10% Pumpkin Juice and Stirred Bio-yogurt Fortified with 10% Dibs at (Day14) and these flavored treatments were higher than control where T2(Stirred Bio-yogurt fortified with 10%pumpkin Juice was the highest values in Zn and K and higher than control. T3( Stirred Bio-yogurt fortified with 10%Dibs was the highest values in Mg , Mn, Ca and P and higher than control values.T4(Stirred Bio-yogurt fortified with 10%Graviola Juice had the highest values in Cu ,Fe, Se and was higher than control values.