الفهرس | Only 14 pages are availabe for public view |
Abstract Fortification is an important process to enhance the food through increasing the content of its essential micronutrients such as minerals and vitamins. Efforts have been devoted to find suitable carriers by which nutraceuticals are transmitted to the human body. Fermented dairy products have been utilized to deliver nutritional components into human diet, since these products are amongst highly consumed food products in the world. Therefore, nutrition scientists reported about utilization of plant resources (vegetables, fruits, cereal, seeds, etc.) or their ingredients (dietary fiber, phenolic compounds, phytosterols and isoflavones) in fortification of dairy products as one of the best methods to improve the overall nutrient intake of dairy products. Currently, due to consumption of milk products by a large category at a high rate like yogurt, led to the fortification of these products which will effectively reduce or prevent diseases associated with nutritional deficiencies especially in children and this will impact on enhancing the health of the community. The main objective of the current study was to prepare some dairy products using chia either whole seed, grinded or freeze-dried chia mucilage, these products included mango stirred yoghurt, sour cream and whipped cream fortified with nutrients that prevent or reduce heart disease, cholesterol, celiac and colitis. The results obtained from the present study, can be summarized as follows: 1. Chia seeds contained high % of high quality crude protein (23.3 g/100g), featured with essential amino acids that cannot be synthesized by the human body which can cover a part of daily needs. 2. High content of crude fat (33.69 g/100g) in chia seeds, that contain high level of ω-3 (α- linolienic acid (49.17%) and high ratio of USFA/SFA (4.7) comparing to other oil seeds; that prevent heart disease and hyper-cholesterolemia. 3. Chia seeds characterized with a high % of fiber 27.8%, which acts as a regulator of intestinal movement, reduce colon inflammation and the sense of satiety, which helps in reducing weight. 4. Chia seeds contained phenolic compounds such as kaempferol, quercetin and gallic acid, which possess antioxidant activity that attacks free radicals and prevent body cells from cancer. 5. Chia seeds showed 3 layers before mucilage extraction clearly identified in microstructure using scan electron microscope which contain mucilage, then rupture of these layers after extraction with layer of mucilage attached to the seeds’ surface. 6. The attached mucilage showed a hexagonal bee-cell like patterned structure that is an optimal solution for keeping a higher amount which explained the mucilage amount attached to the seeds. 7. The mucilage appeared in overlapping sheets in the magnification of (200μm, X85), then increasing magnification a fibrous structure of bio-polymers was obvious (1000μm, X10) 8. Fourier transform infrared spectrophotometer (FTIR) revealed chia functional groups represented in carboxyl group (-COO-) of uronic acid, C=O, C-O-C present in the pyranose ring, C-O-C of glycosidic bond, C-OH bending of polysaccharide compounds, that reflect the high dietary fiber content of chia seed (27.8%) and its mucilage (10.98%). FTIR also revealed the chia protein (N-H) bands of proteins content and CH bands of fats reflecting seeds fat and protein content (33.69% and 23.24%) respectively. 66 9. Comparing FTIR analysis of chia and its mucilage with commercial stabilizers; the results revealed that the three types of modified starch contained carbohydrates and polysaccharides functional groups and some protein functional groups reflecting their (0.5%) content of protein. The main functional groups of gelatin were protein such as amine (N-H), amide (C=O) and (C=C) as the characteristic of R aromatic ring related to peptides produced by partial hydrolysis of collagen extracted from the skin, bones, and connective animals’ tissues. 10. Thermo-gravimetric Analysis (TGA), a conventional technique used to study material thermal stability related to weight loss, was applied to evaluate chia and its mucilage applicability in different heat treated food preparations such as fermented dairy products and bakery comparing with commercial stabilizers revealed that; • Low rate of weight loss (less than 5%) reflected chia flour and freeze-dried mucilage heat stability which continued to 200oC, while the chia whole seeds showed less heat stability through a third stage (~150– ~200°C), losing another 5% of its weight, which support their application in heat treated food products. • Modified starch showed higher thermal resistance than chia three forms to lose less than 10% up to 200 °C (7.27% of sample’s weight). • Gelatin showed different pattern from chia and modified starch, to lose only 3% of its original weight from (~25– ~100 °C), and 1% up to 150 °C and another 1% until 200°C, which characterizes it as a material with a fairly wide range of heat |