الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Barley (Hordeum Vulgare L.) is regarded as the most ancient cultivated grain; it was a staple food in Egypt as early as 6000 B.C.
The principal uses of barley are as feed for animals, in the form of barley meal, and as grain for malting and brewing in the manufacture of beer and wisky. During the last years, barley had received increased attention as a healthy cereal for human consumption, due to the high amount of dietary fiber, especially (1/3), (1/4)-ß-D-glucans (ß-glucans). Actually foods formulated with soluble dietary fiber had been shown to lower serum cholesterol levels and postprandial blood glucose and insulin response.
Barley flour can easily be incorporated into wheat-based products, including bread, cakes, biscuits and extruded snack foods.
Talbina is a food product with high potential applications as a functional food; it was made from whole barley flour. Talbina was prepared from two barley varieties namely: Giza126 and Giza130 by adding whole barley flour to water (1:10 w/v) and (1:5 w/v) for germinated barley then heating at 80° C for 5 minutes with continuous stirring until reaching a porridge like texture.
The present investigation was carried out in an attempt to clarify the nutritional assessment of two barley varieties (Giza 126 as hulled barley and Giza 130 as hull-less barley) by determination chemical composition and their content of amino acids, fatty acids, dietary fiber and ß-glucan, minerals and vitamins; also the present study was conducted to show the possible effects of germination and thermal treatment (talbina and germinated talbina) on chemical and functional properties of barley flour.
Furthermore, talbina and germinated talbina (made from the whole barley flour and germinated barley flour; respectively.) were used as a good source of dietary fiber in enriched biscuits in an attempt to clarify the nutritional assessment of talbina as a functional food in fortifying biscuits.
The obtained data could be summarized as follows:
5-1- Gross chemical composition:
The gross chemical composition as well as caloric value of raw barleys, germinated barleys, talbina, germinated talbina and commercial talbina was determined.
The carbohydrate content, protein, crude fat, crude fiber, ash and moisture of studied barley varieties (Giza 126 and Giza 130) was recorded 81.86% & 78.49%, 8.75% &11.77%, 2.70% & 2.90%, 3.83% & 4.20%, 2.86% & 2.64% and 11.90% &11.57%; respectively. The 1000 grains weight was 43.21gm (in Giza 126) and 45.42gm (in Giza 130).
Germination of barley varieties and thermal treatment of whole germinated barley flour (germinated talbina) increased the content of protein and crude fiber, while total carbohydrate, crude fat and ash were decrease. whereas the thermal treatment of whole barley flour (talbina) caused a decrease in fat content and increase the content of total carbohydrate, crude fiber and ash.
5-2- Dietary fiber content:
Hull-less barley (Giza 130) was recorded a higher value in content of total dietary fiber (TDF), insoluble (IDF) and soluble dietary fiber (SDF) than hulled barley (Giza 126). The content of TDF, IDF and SDF in Giza 126 and Giza 130 was 18.90% & 22.65%, 11.55% & 13.97% and 7.35% & 8.68%; respectively. The present study indicated that there was a trend to decrease total, insoluble and soluble dietary fiber after germination treatment, while the thermal treatment (talbina and germinated talbina) caused an increase of soluble dietary fiber.
Furthermore, talbina126 had the highest percentage of total (TDF) and insoluble dietary fiber (IDF); while talbina130 had the highest value of soluble dietary fiber (SDF).
5-3-Extractable ß-glucan:
The extractable ß-glucan recorded 1.70% and 2.50% in studied varieties (Giza126 & Giza130).
Germination treatment in both varieties (Giza126 & Giza130) caused a decrease in ß-glucan content compared with raw varieties. While, talbina (cooked barley flour) recorded a noticeable increase in extractable ß-glucan content; moreover, talbina130 recorded the highest percentage of extractable ß-glucan (12.10%), which was significantly higher as compared to other studied samples.
5-4-Amino acids composition:
In the present study the essential amino acids of raw, germinated barley and talbina products were determined; and the study indicated that phenylalanine was the highest essential amino acid, followed by leucine.
In general, all studied treatments recorded higher content of all essential amino acids than that suggested by the FAO (1985) reference protein except of methionine, which had a low value in all studied treatments, with the exception of talbina130 treatment, which recorded higher value than that suggested by the FAO (1985) reference protein.
Generally, there was a trend to increase the content of the most essential amino acids after germination treatment, which included isoleucine, leucine, methionine, phenylalanine, and tryptophan, and the results showed that germinated126 increased by 55.49%, 56.16%, 3.18%, 76.70% and 15.50%; respectively, whereas in germinated 130 the same amino acids increased by 12.80%, 0.20%, 38.30%, 21.50% and 74.57%; respectively.
Talbina treatment (cooked barley flour) resulted in a noticeable increase in the most of the essential amino acids including isoleucine, leucine, lysine, methionine, phenylalanine and tryptophan, which increased by 93.45% & 121%, 8.22% & 115.4%, 9.3% & 72.1, 378.3% & 271.6%, 151.2% & 258.4% and 25.8% & 31.6% in talbina 126 & talbina 130; respectively.
On the other hand, there was a general trend to decrease the most of essential amino acids in germinated talbina treatment (cooked germinated barley flour), except tryptophan, which had a noticeable increase by that treatment.
The present study revealed that, the first limiting amino acid was methionine in raw and germinated barleys; while in talbina the first limiting amino acid was threonine when human milk was used as the reference protein.
Actually, talbina and germinated talbina considered as a rich source of isoleucine, phenylalanine and tryptophan when compared with FAO requirement patterns. On the contrary threonine was decreased after all studied treatments, as well as lysine, which decreased except in the case of germinated 126.
5-5-Lipids composition:
5-5-1. Total lipid fractions:
TLC analysis of raw barleys, germinated barleys, talbina, germinated talbina and commercial talbina, indicated that triglycerides showed the highest percentage among lipid fractions (33.92-60.82%) followed by 1,3diglycerides (6.78-20.43%).
Germination and thermal processes (talbina and germinated talbina) caused a decrease in the polar lipids, triglycerides and sterol esters + hydrocarbons. whereas, monoglycerides; 1, 2; 2, 3 and 1, 3 diglycerides; sterols and free fatty acids recorded an increase with the same treatments.
There was a negative relationship between the triglyceride compounds and free fatty acids content; and such relationship appeared in raw 126, which had the highest percentage of triglycerides and lowest percentage of free fatty acids.
5-5-2. Fatty acids composition:
The gas chromatographic analysis of the methyl esters of raw, germinated barley and talbina products oils indicated that total unsaturated fatty acids represented 71.06 &71.75, 72.68 & 80.50, 76.89 &78.59, 70.30 &74.41 and 71.50%. whereas, total saturated fatty acids recorded lower value, which was 25.03& 23.22, 24.17 &18.69, 21.03 & 20.52, 24.52 & 23.48 and 24.92% of raw, germinated barleys, talbina, germinated talbina and commercial talbina; respectively.
Germination and talbina treatments had an increment in unsaturated fatty acids and recorded the lowest value of saturated fatty acids.
The essential fatty acid linoleic (C18:2) recorded the highest percentage of the unsaturated fatty acids (53.59%) in germinated 130. While palmitic acid (C16:0) recorded the highest value of saturated fatty acids in germinated 126 (17.44%).
5-6-Mineral composition of samples:
In the present study Ca, P, Mg, K, Na, Fe, Zn, Cu and Mn; were determined in raw, germinated barley and talbina products and it was ranged as follow, 120-160, 300-510.4, 130-180, 240-320, 15.17-47.35, 5.75-13.85, 3.31-39.9, 0.550-0.985 and 1.02-2.67 (mg/100g); respectively.
With germination treatment iron, manganese, copper and zinc contents decreased, whereas calcium and phosphorus were increased. On the contrary, by making talbina iron, manganese, copper and zinc increased especially zinc, which recorded higher value than that recommended daily. While, sodium was decreased after all studied treatments and recorded the lowest value in germinated talbina126.
5-7-Vitamins:
In raw varieties (Giza126 & Giza130) vitamin E recorded 449.20 and 576.75(IU/100g); respectively.
Germination process increased the amount of vitamin E, and germinated130 had recorded the highest amount of vitamin E (622.33 IU/100g or 416.90 mg of α-tocopherol/100g).
While the thermal process caused a decrease in vitamin E, which decreased by 27.90%, 40.50%, 17.48%, and 30.27% in talbina126, talbina130, germinated talbina126, and germinated talbina130; respectively.
There was a trend to increase the content of riboflavin (B2) and pyridoxine (B6) by germination treatment; thus, germinated 130 had the highest amount of thiamin (B1).
While thermal process (talbina and germinated talbina) increased nicotinic acid content; furthermore, germinated talbina130 had recorded the highest amounts of vitamins B2, Nicotinic acid, B6 and folic acid.
5-8-Functional properties:
In the present study water absorption capacity (WAC) was 1.77& 1.93(g/g), oil holding capacity (OAC) was 0.818 & 0.892 (g/g) and water solubility index (WSI) was 6.02 & 7.98% in raw barleys (Giza 126 & Giza 130); respectively.
Water absorption capacity and oil holding capacity were decreased after germination treatment in both varieties (Giza126 and Giza130); while water solubility index was increased. In talbina and germinated talbina samples water absorption capacity, water solubility index and oil holding capacity were increased.
5-9-Talbina products:
5-9-1- Sensory evaluation of talbina:
The results revealed that color, texture, taste, odor and overall acceptability in germinated talbina had higher scores than talbina and commercial talbina.
5-9-2- Biscuits:
The present study was carried out on biscuits prepared by incorporating talbina130 and germinated talbina130 (10%, 20% and 30%) into wheat flour. The biscuits were evaluated for their physical, chemical, nutritional and sensory characteristics.
In general, all the biscuits samples recorded high protein, fiber, ash and minerals contents as compared to that made from 100% wheat flour (control). Besides, the all biscuits recorded rather slight decrease in crude fat content. Moreover, biscuits incorporated with 30% germinated talbina130 recorded highest value of spread ratio (11.25) as well as spread factor (135%). The data revealed that both of biscuits enriched with10% talbina130 and biscuits enriched with10% germinated talbina130 recorded the best sensory values, including color, texture, taste, odor and overall acceptability.
In conclusion, on the light of the above –mentioned data barley talbina proved to have high levels of minerals, (especially zinc and iron), vitamins E, nicotinic and pyridoxine as well as it recorded good balanced amino acids composition required for human nutrition.
Enriched biscuits with talbina proved to be a nutritious food product, which could be recommended for diabetic, hypercholesterimc and obese patients due to its both soluble and insoluble dietary fiber as well as its high content of ß-glucans. Besides, biscuits enriched with talbina had high levels of important minerals as compared to biscuits made from 100% wheat.