جستجوی مقالات مرتبط با کلیدواژه « عصاره چای سبز » در نشریات گروه « صنایع غذایی »

In this study, the effect of adding green tea extract (10%) on physicochemical, sensory, microbial and viability characteristics of probiotic bacteria in Pinacolada drink based on whey was investigated. The results showed that as a result of adding green tea extract, physicochemical properties such as pH, brix, dry matter and protein content of the drink did not change significantly, but the turbidity of the drink increased compared to the control sample (without green tea). The results of microbial evaluation showed that the sample containing green tea extract was free of microbial contamination compared to the control sample, which indicates the antimicrobial properties of green tea extract. Although CFU / ml 2 mold was observed in the control sample, but this amount is less than the standard and can be consumed. Unlike Bifidobacterium bifidum, the probiotic bacterium Lactobacillus acidophilus did not grow in beverages. Also, the survival of Bifidobacterium bacteria during 28 days of refrigeration and passing through stomach and intestinal conditions had a decreasing trend, which was more in the drink containing green tea extract than the control sample. However, until the 21st day, the viability of microorganisms in beverages containing green tea extract was maintained at the recommended level according to the Iranian National Standard (106 CFU / ml). An appropriate concentration of green tea extract can be used in the production of pinacolada probiotic drink based on whey as a new useful beverage.

Today, consumers tend to eat fresh food with high nutritional and health benefits. Food, in addition to eliminating hunger and providing essential nutrients, should improve the health and physical and mental health of the consumer. Probiotics are living microorganisms that have a healthy effect if they are consumed alive and sufficiently. Using appropriate prebiotic compounds and selecting suitable carriers for probiotics can increase the growth and activity of these beneficial bacteria. Soybeans and their products are considered to be good carriers for probiotic microorganisms that can play an effective role in increasing the viability of probiotic bacteria. The purpose of this study was to investigate the effects of inulin prebiotic and antioxidant green tea on increasing the viability time of Bifidobacterium longum in synbiotic soy ice cream.

In order to produce synbiotic soy ice cream, the green tea extract in concentrations of 1, 2 and 3% and inulin in proportions of 1, 2 and 3% and also probiotic bacteria Bifidobacterium Longum in the amount of 107 Cfu/ml were added to synbiotic soy ice cream formulation. Therefore, 10 treatments were designed according to completely randomized design with three replicates. Tests of determination the percentage of polyphenolic compounds, percentage of total acidity, percentage of increasing overrun, peroxide number (mEq/Kg), viscosity evaluation (cp), color assessment (lighting, redness and yellowness index), sensory assessments (odor, taste, texture and overall acceptance) were performed one day after production and the survival rate of Bifidobacterium Longum (Cfu/ml) of soybean ice cream samples done during 21 days of storage at -18°C. For data analysis of the results of the tests, Duncan's test for comparison means at probability level of 5% was used by Minitab version 16 software.

The results showed that increasing the concentration of inulin and green tea extract in the synbiotic soy ice cream formulation, overrun, yellowness index (b*), lighting index (L*), score of sensory indexes including odor, taste, texture and overall acceptance decreased and acidity, the viability rate of Bifidobacterium longum, viscosity and redness index (a*) increased. Bifidobacterium longum population after 21 days of storage in all treatments, including control, was higher than 106 Cfu/ml. In contrast to inulin increase in the concentration of green tea extract had a significant effect on the reduction of peroxide index. The sensory indices of the treatment containing 1% green tea extract and inulin were not significantly different with the control sample and were presented as superior treatment in this study. Sensory indexes of treatments containing 1% green tea extract and inulin were not significantly different with the control sample and were presented as a superior treatment in this study.

By using 1% green tea extract and 1% inulin can be possible to produce a synbiotic soy ice cream with optimal qualitative and sensory properties with good health properties.

Kefir is one of the fermented milk products that plays a major role in nutrition and human health. The aim of this study was to investigate the effect of adding asparagus extract and green tea extract on survival of probiotic bacteria, antioxidant activity and sensory properties of kefir. Different concentrations (0.5, 1 and 1.5%) of asparagus extract and green tea extract were used in kefir and the samples were stored at 4˚C for two weeks.The results showed that addition of herbal extracts decreased pH and increased acidity and antioxidant activity of the samples (p≤0.05). The highest antioxidant activity was related to the sample containing 1.5% green tea extract. During storage time, pH of the samples decreased, but acidity increased significantly (p≤0.05). There was no significant difference between samples in terms of viability of Bifidobacterium lactis and Lactobacillus acidophilus (p>0.05). The viability of probiotic bacteria decreased significantly (p≤0.05) during storage but in all samples, the number of bacteria was more than 108 CFU/ml until the end of the storage period. The sample containing 1.5% asparagus extract had the highest score of overall acceptance. Therefore, this sample was selected as the best treatment.

Yazdi cake is one of the indigenous snacks of Iran that by adding some ingredients can improve its nutritional and textural properties. Green tea extract is high in antioxidants and have a health role. The aim of this study was to investigate the effect of green tea extract on physicochemical and sensory properties of Yazdi cake. In this study, green tea extract was added to Yazdi cake formulation at 0, 2.5, 5 and 10% levels. Then the physicochemical properties (moisture, protein, fat, ash, fiber, carbohydrate, Specific weight for cake dough, cake volume, density, porosity, weight loss) and sensory analyze during storage at 2, 4 and 6 days intervals after baking, it was performed according to standard methods. All the prepared cakes containing different concentrations of extract had significant physico-chemical and sensory characteristics and were within the standard range. Observations showed that the addition of green tea extract in cake formulation decreased weight loss, moisture, porosity, density, brightness, ash and sensory scores and increased volume, fiber, fat, protein, carbohydrate and specific gravity. High levels of 5% green tea extract had a negative effect on the quality of the cake. Therefore, the addition of green tea extract at levels of 2.5 and 5% produced an acceptable product cake. Finally, optimization of Yazdi cake formulation to produce a useful product using the investigated characteristics and limits indicated that 2/5% of green tea extract is the most suitable enrichment for Yazdi cake, in which the percent extract there was no adverse change in the physicochemical and sensory properties of the cake.

The Mazafati date is one of the most important export products of Kerman province, which their quality characteristics may change during storage. The use of edible coatings is a new technique for increasing the shelf life of various agricultural products. The aim of this study was to investigate the effect of Aloe vera containing salicylic acid (2 mM) and green tea extract (0.5%) on physicochemical, microbial and sensory properties of stored dates at 4 and 25 °C for 150 days. The results of analysis of variance showed that the coating, temperature and time of storage had significant effects on the evaluated parameters (p <0.05). According to the results, the lowest weight loss was observed in samples coated with Aloe vera containing green tea extract and salicylic acid. This type of coating prevented significant changes in pH, acidity, total soluble solids (°brix), total and reducing sugar contents of date samples compared to the control during the storage period. During the storage period, the pH and total sugar content decreased, and acidity, total soluble solids and reducing sugar content increased. Total phenolic content did not have a clear trend during the storage period and its amount in the coated samples was significantly higher than the control. Aloe vera containing green tea extract and salicylic acid also effectively prevented microbial growth. In addition, panelists gave higher scores to dates coated with Aloe vera containing green tea extract and salicylic acid. The changes in physicochemical, microbial and sensory parameters in the stored dates at 25 °C were significantly higher than that stored at the temperature of 4 °C. In general, the use of Aloe vera containing green tea extract and salicylic acid, and storage at 4 °C is recommended due to the reduction of microbial growth and maintaining the quality characteristics of Mazafati date.

There are several methods to improve the viability of probiotic bacteria in fruit juices such as the use of antioxidant compounds. In this study, effect of green tea extract ( 1.5, 2.5 and 3.5%) as an antioxidant was examined against the survivability of Lactobacillus acidophilus (PTCC 1643), physico-chemical, antioxidant (DPPH radical scavenging) and organoleptic properties of watermelon juice, during 21 days of storage at 4 °C. The pH of samples decreased during 14 days of storage and then increased during the next 7 days. The same results were observed for acidity of samples. Antioxidant activity of all samples containing green tea extract was significantly (P<0.05) higher than control sample and decreased significantly (P<0.05) during storage time. According to our results, the viability of probiotic bacteria increased significantly (P<0.05) by increasing the concentration of green tea and a direct relation was observed between antioxidant activity and viability of probiotic bacteria. In conclusion, by considering all physicochemical, organoleptic properties and survivability of probiotic bacteria, the sample containing 2.5% green tea was recognized as the best treatment.

In this research the effect of green tea extract on some qualitative and rheological properties of rosette was studied. Green tea extract with percentages of 0.5, 1 and 1.5 wet basis were used. Rosette dough rheological behavior measured by rotational viscometer at 20, 35 and 50 ° C and speeds10-200 rpm. The effect of temperature on the viscosity and stability of rosette was evaluated using the Arrhenius equation and then activation energy was calculated. The results of this research showed that with increasing temperature, viscosity significantly decreased. Mathematical calculations of finding in basis of Mitchka method showed that the rosette dough was non-Newtonian fluid and the shear thinning. Then the rosette dough was fried for two minutes at 150 ° C. Then oxidative stability index, peroxide and acid index were measured for samples. Results showed using green tea extract caused reduce the peroxide value, acid value and increase oxidative stability index. Use of green tea extract had postponed oil hydrolysis rate and increase the acid value.

According to the increasing importance of nutrition in the world, consumer prefer use products with good taste and salutary. Green tea extract in one of those compounds with an antioxidant effect. With increasing obesity in modern societies and the prevalence of diseases such as cardiovascular failure, blood sugar and also to prevent tooth decay, Low calorie products and sugar free products have been noticeable.
The purpose of this investigation was to determine the effect of using green tea extract in 0.4, 0.7 and 1% in formulation and replacing sugar with stevia at level of 0.2, 0.4 and 0.6% in the produce of non sugar muffin and salutary product.
The statistical analysis was presented using the response plane and central composite design. Physical and rheological properties of the batter, including density and viscosity, as well as physical and chemical characteristics of the cake including moisture, water activity, volume, height, pH, hardness, antioxidant property, index of peroxide and characteristic Sensory senses of muffins were evaluated. The results showed that there was a significant difference in volume, texture stiffness, water activity, sensory evaluation, antioxidant and peroxide properties. Sensory evaluation indicated that with increasing the stevia and green tea extract, satisfaction decreased in all sensory characteristics. In general, the muffin with 0.2% stevia and 0.4% green tea extract can be the best sample.

One of the plant extracts which has antimicrobial, antioxidant, nutritional and medicinal properties is extract of green tea. In this study, the effect of different concentrations of green tea extract (%10, %20 and %30) was studied on qualitative and microbial characteristics of bovine meat during storage. For this purpose, extraction carried out from green tea leaves and then chopped meat was immersed with a ratio of 1 to 1 (pieces of meat to different concentrations of green tea extract) for 20 hours at 4 °C. Finally, the pieces of meat were packaged and various tests were conducted in the storage period (1, 5, 10 and 15 days). The results showed that treatment of meat with green tea extract had a significant effect (P

The mackerel (Scomberomorus commerson; Scombridae) also known as "Sheer fish" in Persian, is the most popular fish in Iran with the highest economic value. This fish is mainly offered on the Iranian market as skinned and boneless fillets. Major changes occur in proximate, microbiological, chemical and sensory composition of fish fillets during storage in the refrigerator. To preserve the fish fillet, antioxidant additives prior to packaging is a common practice used in food market to extend the shelf life of aquatic products. Currently, synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) frequently have been used prior to packaging. However, recently the consumers’ demand has ben changed to fillets with natural preservatives such as green tea extract (GTE), usually packaged in vacuum packaging (VP). Green tea is a good source of polyphenolic compounds such as catechina having strong antioxidant and antimicrobial properties. Incorporating GTE as a food additive due to its antioxidant activities is a growing interest in the seafood industry. GTE can improve the marketing potential of various seafood products and can effectively be used in the packaging food industry.
Mackerel, Scomberomorus commerson was purchased from a local fish market in Abadan city, Khozestan province, Iran. Fish were freshly caught and completely free of additives. The fish samples were kept in ice with a fish/ ice ratio of 1:2 (w/w) and transported to the seafood processing laboratory within one hour. Upon arrival, fish samples were washed in cold water and each sample was carefully filleted by hand. Two fillets were obtained from each fish after removing the head and bone. Mackerel fillet were soaked with 1 g GTE/ L solution at a fillet/solution ratio of 1: 2 (w/v) for 15 min at 4 °C, followed by draining on the screen for 3 min at 4 °C. The trays of containing samples were then vacuum- packaged (VP).
The results indicated that the bacterial experiments (total count and pscychrotrophic bacteria) showed the antibacterial effect of green tea extract. Lipid oxidation value experiments (peroxide and thiobarbituric values) showed lower oxidation value in fillets treated with GTE, compared to fish kept under vacuum packaging without treatment and the control (P

The aim of this study was to investigat the effect of modifierd starch and maltodextrin as a wall material on the microencapsulation of ginger oil in green tea extract by spray drying method. Ginger oil was encapsulated with modiferd starch, maltodextrin, and mixture of these by ratio(2:1¡ 1:1¡ 1:2) .The mean droplet size of emulsion and Encapsulation efficiency, oil surface, particle size and moisture of microcapsul was evaluated. The results showed that by reducing the Gum Arabic content and increasing Maltodextrin content, the emulsion particle size became larger. Encapsulation efficiency increased and oil surface decreased by the decreas in particle size of emulsion and powder. And the results indicated the lack of effect of rim material on the amount of moisture. A 2:1 and 1:1 blend of Gum Arabic:Maltodextrin offered a protection, better than gum Arabic and maltodextrin .

The effect of vacuum packaging on the shelf life of white shrimp (Metapenaeus affinis) treated with and without coating green tea extract (1 g/L) during refrigerated storage (4 ºC) during 10 days was investigated for determine of peroxide value, thiobarbitoric acid, free fatty acids, melanosis (black spot) and sensory properties. The coincidental lowered rate of increase in peroxide value, thiobarbitoric acid and free fatty acid were obtained in shrimp stored under vacuum packaging (P

Effect of green tea extract and its natural antibacterial on microbial spoilage rainbow trout during ice storage was investigated. In this research fishes in whole fish form and dipped in antibacterial solutions (200، 400، 600 ppm) for 90 minutes and then were icing. During storage period (16 days)، spoilage microbial indices (TVB-N، TVC، PVC) and pH with interval of 4 days were measured and compared with control treatment. Based on obtained results in all of treatments by passing time the value of total volatile nitrogen increased significantly (P < 0/05). But this increase in treatment of 600 ppm performanced slowly. In control treatment by passing time Total viable count increased significantly (P < 0/05). Except in level of 600 ppm، other levels did not significantly different until sixteenth day in comparison with control treatment. In passage of time، Psychotroph viable count (PVC) in all of treatments was increased while control treatment in twelfth day and levels of 200 and 400 ppm in final period storage time were aggressive allowable content but 600 ppm level in final period was lower than allowable content (6/89±0/15 log cfu/gr). The value of pH was increased in all of treatments. Obtained results showed that green tea extract with dipping whole fish in consternation of 600 ppm was suggested for retardation of microbial spoilage in rainbow trout during storage in ice.

The objective of this research was to discriminate the best dietetic cookies formulation for diabetic and heart patients. For this purpose, isomalt up to 36% of flour weight was used as a substitute for sucrose. As a result, blood sugar and insulin levels did not change significantly after consumption. Licorice root powder (1, 2, and 3%) was added for maintenance and producing desirable flavor. In addition green tea extract was used for its high antioxidant capacity. Green tea extract can be effective against diabetes, because it boosts insulin activity in the body. Olive oil was also used in the formulation to reduce glucose levels, LDL and triacylglycerol levels in blood. Based on chemical analysis (moisture, protein, fat, ash and carbohydrate content) and organoleptic analysis, an optimized formulation determined for production of a dietetic and low calorie cookies. Addition of licorice root at level of 3% produced a significant bitter after taste but 2% licorice root did not affect flavor desirability and total acceptance (P<0.05). Addition of 4% green tea extract and 3% olive oil did not have significant effect on flavor, texture and water content of the product. Blood glucose concentrations of six non-insulin-dependent diabetic patients were compared using duncans multiple range test after 0, 1 and 2h of consumption of control and sample 2. Fasting blood sugar levels of these patients did not have significant differences (P<0.05) but after 1h, blood glucose concentration in patients that consumed control sample was increased significantly.

In this research green tea extract was prepared with water and then fishes in whole and gutted fish form was dipped in solutions of green tea extract (600 ppm) for 90 minutes and then were icing. During storage period (16 days)، spoilage oxidation (PV، FFA، and TBA)، spoilage microbial indices (TVB-N، TVC، PVC) and Sensory assessment with interval of 4 days were measured and compared with control treatment. Based on obtained results in all of treatments by passing time the value of all of the indexes (PV، FFA، TBA، TVB-N، TVC and PVC) increased significantly (P < 0/05). But this increase in treatments dipped in 600 ppm solution was performance slowly. Also in gutted fish form was caused higher delay in lipid oxidation and spoilage microbial relate to whole fish form. According sensory assessment results not significantly different among treatments (P > 0/05). In conclusion Obtained results showed that green tea extract with dipping gutted fish in consternation of 600 ppm was suggested for retardation of lipid oxidation and microbial spoilage in rainbow trout during storage in ice.

A group of the natural antioxidants is the polyphenols in green tea leave extracts (GTE). In this research، the extraction of antioxidants from the leaves was done with aqueous solution and then the extract was purified and finally dried and made into powder. Then the antioxidant effects of produced powder and α -tocopherol at 200 and 500 ppm، butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at 100 and 200 ppm، and the combination synergistic effect of mixtures: 200 ppm GTE+500 ppm α -tocopherol، 500 ppm GTE+200 ppm BHA and 500 ppm GTE+200 ppm BHT in two types of sunflower oil (with and without citric acid as a chelator) at 50oC and time intervals of 0، 5، 8، 12 days were examined and compared for peroxide value (PV) and thiobarbituric acid (TBA) test. Results showed that the individually antioxidant effect of GTE at both concentrations was better than that of other antioxidants. Combination of GTE+BHT demonstrated antagonistic effect but no remarkable synergism or antagonisim was observed in other combinations.