Abstract: Bacterial Cellulose (BC) is a structural organic compound produced in the anaerobic process. This material can be a useful eco-friendly substitute for commercial textiles that are used in industries today. BC is easily and sustainably produced and has the capabilities to be used as a replacement in textiles. However, BC is extremely fragile when it completely dries. This research was conducted to improve the mechanical properties of the BC by reinforcing with an organic polymer and exfoliated graphite (EG). The BC films were grown over a period of weeks in a green tea and kombucha solution at 30 °C, then cleaned and added to an enhancing solution. The enhancing solutions were a mixture of 2.5 wt% polymer and 2.5 wt% latex solution, a 5 wt% polymer solution, a 0.20 wt% graphite solution and were each allowed to sit in a furnace for 48 h at 50 °C. Tensile test samples were prepared and tested until fracture at a strain rate of 8 mm/min. From the research with the addition of a 5 wt% polymer solution, the flexibility of the BC has significantly improved with the maximum strain significantly larger than that of the base sample. The addition of EG has also increased the modulus of elasticity of the BC by about 25%.
Abstract: The application of natural plant extracts which are rich in promising antioxidants and antimicrobial ingredients in the production of frankfurter-type sausages addresses consumer demands for healthier, more functional meat products. The effects of olive leaves, green tea and Urtica dioica L. extracts on physicochemical, microbiological and sensory characteristic of frankfurter-type sausage were investigated during 45 days of storage at 4 °C. The results revealed that pH and phenolic compounds decreased significantly (P < 0.05) in all samples during storage. Sausages containing 500 ppm green tea extract (1.78 mg/kg) showed the lowest TBARS values compared to olive leaves (2.01 mg/kg), Urtica dioica L. (2.26 mg/kg) extracts and control (2.74 mg/kg). Plant extracts significantly (P < 0.05) reduced the count of total mesophilic bacteria, yeast and mold by at least 2 log cycles (CFU/g) than those of control samples. Sensory characteristics of texture showed no difference (P > 0.05) between sausage samples, but sausage containing Urtica dioica L. extract had the highest score regarding flavor, freshness odor, and overall acceptability. Based on the results, sausage containing plant extracts could have a significant impact on antimicrobial activity, antioxidant capacity, sensory score, and shelf life stability of frankfurter-type sausage.
Abstract: The objective of the present study was to investigate the effect of green tea extract on serum oxidant and antioxidant profile, liver and kidney function. 40 Friesian calves are included in this study and allocated into two groups: Group I (n=20) clinically healthy calves showing no clinical abnormalities, not receiving any treatment and served as control; group II (n=20) received green tea extract (GTE) for 30 days. Non-significant changes in blood urea nitrogen (BUN) were detected between groups, on contrary, serum creatinine and activities of liver enzymes aspartate transaminase (AST) and alanine transaminase (ALT) were significantly different between two groups. There were significant increases in the mean values of serum antioxidative parameters (total antioxidant capacity, catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase) in group II. Whereas, the activity of lipid peroxidase significantly decreased in GTE treated calves when compared to control.
Abstract: Green tea is made from the top two leaves and buds of a shrub, Camellia sinensis, of the family Theaceae and the order Theales. The green tea leaves are picked and immediately sent to be dried or steamed to prevent fermentation. Fluid bed drying technique is a common drying method used in drying green tea because of its ease in design and construction and fluidization of fine tea particles. Major problems in this method are significant loss of chemical content of the leaf and green appearance of tea, retention of high moisture content in the leaves and bed channeling and defluidization. The energy associated with the drying technology has been shown to be a vital factor in determining the quality of green tea. As part of the implementation, prototype dryer was built that facilitated sequence of operations involving steaming, cooling, pre-drying and final drying. The major findings of the project were in terms of quality characteristics of tea leaves and energy consumption during processing. The optimal design achieved a moisture content of 4.2 ± 0.84%. With the optimum drying temperature of 100 ºC, the specific energy consumption was 1697.8 kj.Kg-1 and evaporation rate of 4.272 x 10-4 Kg.m-2.s-1. The energy consumption in a fluidized system can be further reduced by focusing on energy saving designs.
Abstract: Tea is one of the most consumed beverages all over the world. Especially, black and green teas are preferred to consume. In Turkey, some local tea houses use sodium bicarbonate (SB) to obtain more infusion by using less than the amount of tea. Therefore, the addition of SB to black and green teas affects element concentrations of these teas. In this study, determination of magnesium (Mg) and phosphorus (P) contents in black and green teas aimed for conscious consumption, after the addition of SB. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for these analysis. The results of this study showed that the concentrations of Mg and P decreased by adding SB from 11.020, 21.915 to 10.009, 17.520 in black tea and from 12.605, 14.550 to 8.118, 9.425 in green tea, respectively. The addition of SB on analyzed teas is not recommended to cause reducing intake percentages of Mg and P from the essential elements.
Abstract: Tea is a widely consumed beverage that contains many components. Caffeine belongs to this group of components called alkaloids contain nitrogen. In this study caffeine contents of three types of Turkish teas are determined by using extraction method. After condensation process, residue of caffeine and oil are obtained with evaporation. The oil which is in the residue is removed by hot water. Extraction process performed by using chloroform and the crude caffeine is obtained. From the results of experiments, caffeine contents are found in black tea, green tea and earl grey tea as 3.57±0.43%, 3.11±0.02%, 4.29±0.27%, respectively. Caffeine contents which are found in 1, 5 and 10 cups of tea are calculated. Furthermore, the daily intake of caffeine from black teas that affects human health is investigated.
Abstract: Tea has several types of essential elements. Potassium,
magnesium and phosphorus are some examples of these elements.
Tea is widely used drink in Turkey, also some people puts a lemon
wedge to tea for different taste. In this study potassium, magnesium
and phosphorus contents after the hot water brewing of black and
green tea were determined by Optical Emission Spectroscopy (ICPOES).
Furthermore, how the lemon addition to teas affects the
concentrations of the potassium, magnesium and phosphorus
amount are investigated.
From the results, potassium, magnesium and phosphorus
concentrations are found as 3003.3, 597.1, 1167.2 ppm in black tea
and 3718.0, 3830.5, 376.4 ppm in green tea, respectively. After
lemon addition potassium, magnesium and phosphorus
concentrations are changed to 14930, 830.4, 1113.5 ppm in black tea
and 15460.0, 909.5, 1152.5 ppm in green tea, respectively.
It is seen that lemon addition affects some essential elements in
black and green Turkish teas.
Abstract: The effects of coatings based on sodium alginate (S.A) and carboxyl methyl cellulose (CMC) on the color and moisture characteristics of potato round slices were investigated. It is the first time that this combination of polysaccharides is used as edible coating which alone had the best performance as inhibitor of potato color discoloration during the storage of 15 days at 4oC. When ascorbic acid (AA) and green tea (GT) were added in the above edible coating its effects on potato round slices changed. The mixtures of sodium alginate and carboxyl methyl cellulose with ascorbic acid or with green tea behave as a potential moisture barrier, resulting to the extent of potato samples self–life. These data suggests that both GT and AA are potential inhibitors of dehydration in potatoes and not only natural antioxidants.
Abstract: Tea is consumed by a big part of the world-s
population. It has an enormous importance for the Turkish culture.
Nearly it is brewed every morning and evening at the all houses. Also it is consumed with lemon wedge. Habitual drinking of tea
infusions may significantly contribute to daily dietary requirements of elements.
Different instrumental techniques are used for determination of
these elements. But atomic and mass spectroscopic methods are preferred most. In these study chromium, iron and selenium contents
after the hot water brewing of black and green tea were determined
by Optical Emission Spectroscopy (ICP-OES). Furthermore, effect
of lemon addition on chromium, iron and selenium concentration tea
infusions is investigated.
Results of the investigation showed that concentration of
chromium, iron and selenium increased in black tea with lemon addition. On the other hand only selenium is increased with lemon
addition in green tea. And iron concentration is not detected in green
tea but its concentration is determined as 1.420 ppm after lemon addition.