Showing 10 results for Acor
Volume 2, Issue 3 (7-2000)
Abstract
Different layers of acorn (Quercus infectoria), hull, seed coat and seed kernel were analyzed
for determination of chemical composition. The results of the preliminary analysis
showed that acorn contained more than 65% carbohydrates, 8% lipid and 10% tannin
among other constituents. The fatty acid composition of the seed oil was determined using
thin layer chromatography and comparing with standards. The results showed the presence
of both saturated and unsaturated fatty acids. Saturated fatty acid: are C14:0, C16:0,
C18:0, and C20:0. Unsaturated fatty acid: C18: 1 and C18: 2. Total saturated fatty acids
represented 20% and unsaturated fatty acids contributed 80% to acorn fat content.
Volume 9, Issue 34 (6-2012)
Abstract
Antioxidant properties of plant extracts are apparently related to the content of their phenolic compounds. In this study, phenolic compounds from two acorns varieties namely Q.branti var persica (Q.b) and Q.castaneifolia var castaneifolia (Q.c) were extracted with methanol (80%). After evaporation with rotary evaporator, extracts were dried with freeze drier. The concentrations of phenolic compounds in the extracts were determined according to the Folin-Ciocalteu method, and results were expressed as tannic acid equivalents per gram of dried extract (TAE/g d.e). Castaneifolia variety had the highest phenolic content with 217.65 (TAE/g d.e). Antioxidant activity of methanolic extracts were studied in sunflower oil and compared with synthetic antioxidants, by measuring their peroxide and thiobarbituric acid values during accelerated storage. Methanolic extracts of acorns at three different concentrations (250,500 and 1000 ppm) and synthetic antioxidant at two concentrations were added to sunflower oil. Both extracts retarded the oxidation of sunflower oil at 70°c more efficiently than BHA and BHT. The peroxide and thiobarbitoric acid values of control samles were raised to 328.88 (meq peroxide/ kg oil) and 0.58 (mg malon aldehyde/kg oil) after tewelve days storage while this values were 176.36 and 0.332 for oil sample contain 1000 ppm methanilic extract of Q.c and 183.2 and for Q.b were 0.374, respectively.
Volume 9, Issue 35 (7-2012)
Abstract
In this study, phenolic compounds of acorns (Q.castaneifolia var castaneifolia) were extracted with water and ethanol (70%). Total phenolic content of water and ethanolic (Et) extracts were 238.85 and 142.18 mg TAE/gr dried extracts, respectively. Antioxidant activity was evaluated using three different methods: including scavenging effect on DPPH radicals, reducing power of Fe+3 and total antioxidant capacity. The results were compared with synthetic antioxidant, BHA and BHT. In all the methods, the antioxidant activity was concentration dependent. Ethanolic extract of Q.castaneifolia was the highest in DPPH assay (EC50=34.28 µg/ml). In the reducing power and total antioxidant capacity, BHT obtained the best results followed by ethanolic extract , BHA and water extract. Also, the protective effect of ethanolic extract in stabilizing sunflower oil was tested. Ethanolic extract of acorn at three different concentrations, i.e. 250 (Et-250), 500 (ET-500) and 1000 ppm (Et-1000) was added to sunflower oil. BHA and BHT at 100 and 200 ppm were chosed as standards along with the control. All samples were incubated in open beakers at 70°C in the dark for 12 days. The peroxide and tiobarbitoric acid values of the samples were determined at definite time intervals of 0, 2, 4, 6, 8, 10 and 12 days. Results showed that ethanolic extract at all concentration retarded the retarded the oil oxidation. Et-1000ppm and Et-500 ppm exhibited stronger antioxidant activity compared to BHT-200 and Et-250 was better than BHA-100.
Seyyed Sajad Mousavi Nejad Souq, Gholam Hossein Baradaran,
Volume 15, Issue 8 (10-2015)
Abstract
Frame structures have several applications in industries. They are used to carry all types of loadings. Usually catastrophic failure in these structures initiate from small cracks. Catastrophic failure can be prevented by detecting the cracks early and replacing or repairing the cracked members. The change in dynamics and vibration characteristics is one of the consequences of cracks in structures. In this work, detection of surface cracks in frame structures with regards as the change in natural frequencies of the system is studied. The finite element has been used to compute the natural frequencies of cracked structures. Then, according to the difference in natural frequencies of intact and cracked structures the locations and depths of cracks have been determined by the solution of an inverse problem. For the inverse problem the ant colony optimization algorithm has been employed. It is shown that; while, the changes in natural frequencies are good means for crack detection in a separate beam, it is not sufficient for crack detection in a frame structure. It seems that, other characteristic of the system such as changes in natural modes must be considered.
Volume 16, Issue 97 (2-2020)
Abstract
Acorn tree is abundant in many parts of Iran and is usually wasted or used as animal feed. According to the numerous health effects of acorn, the aim of this research is to investigate the influence of acorn flour (substituted at levels of 0-30% with rice flour, corn flour and starch) as a mixture design on chemical, nutritional, textural and sensorial properties of gluten free biscuits for celiacs. The results showed that moisture, ash, crude fiber, carbohydrate, antioxidant capacity and total phenol of gluten free biscuits supplemented with acorn flour increased noticeably compared to control. Increasing the acorn flour decreased calorie value of gluten free biscuits. Hardness and penetration energy of samples increased with substitution of acorn flour in formulation. Sensory evaluation showed addition of acorn flour up to 20% was acceptable but total acceptance diminished at high levels of it. The obtained results signify that the application of acorn flour in gluten-free baking could be useful for fortification and increase of nutritional value.
Volume 19, Issue 124 (5-2022)
Abstract
Characterization of lactic acid bacteria (LAB) isolated from rarely studied fermentation substrates can lead to isolate unique microorganisms. In the present study, predominant LAB was isolated from fermented acorn using repeat of back-slopping process, and then the isolate was identified by PCR. Subsequently, probiotic properties of the isolate (including resistance to acid and bile, antibacterial, auto and co-aggregations, antibiotic susceptibility and blood hemolysis), as well as its antifungal effect were studied. Sequencing results of the PCR products led to the identification of Pediococcus acidilactis as predominant LAB isolate. The survival percentage of the isolate in continuous acid and bile treatment was equal to 72%. The inhibitory effect of the isolate on Bacillus cereus was also significantly (P<0.05) higher than the other foodborne indicator bacteria. Furthermore, crude cell free supernatant (CFS) obtained from LAB culture completely inhibit the growth of B. cereus; meanwhile, its naturalized CFS had no inhibitory effect on Salmonella enterica. LAB isolate had also proper auto and co-aggregation (with E. coli) potentials and had no hemolytic activity. Antifungal activity of the isolate against Aspergillus niger was also verified. By considering the proper probiotic and antifungal potentials of the P. acidilactis isolated from fermented acorn it is possible to use the isolate as microbial starter, adjunct, probiotic and or protective culture in fermentation industries.
Volume 19, Issue 133 (2-2023)
Abstract
The purpose of this research is to investigate the effect of the changes in the starch slurry with the concentration of 30, 50 and 70% of dry substance of pregelatinized acorn starch using a single drum dryer at a drum temperature of 120°C and a speed of 20 rpm which is called PGS30, PGS50 and PGS70 in order on physical and chemical properties including viscosity, hydration, freezing and melting stability, degree of gelatinization, morphology and FTIR.The rheological properties were evaluated using a rapid viscosity analyzer as a function of temperature. Pregelatinized starches showed viscosity at 25°C in cold water, but native acorn starch did not show viscosity at room temperature. Native acorn starch gradually started to absorb water as the temperature increased. So that the highest viscosity (peak) was created by native acorn starch, PGS30, PGS50 and PGS70 respectively. Native acorn starch granules have a smooth surface and non-homogeneous shape (mostly oval and spherical) and also have surface cavities and wrinkles. The morphology of pregelatinized starches changed significantly so that the granules of PGS50 and PGS70 samples are continuous and porous with a honeycomb-like structure. And there was no significant change in freezing-thaw stability compared to native acorn starch (p<0.05). The spectroscopic evaluation of native acorn starch was consistent with PGS samples up to the spectral range of 13343 cm. But in the PGS70 and PGS50 samples, several spectral intervals occurred between 3747 and 3945, which indicates the complete gelatinization of these two samples. Pregelatinized starches also have more swelling power, water absorption and solubility than native acorn starch (p≥0.05).
Volume 20, Issue 140 (10-2023)
Abstract
The present study aimed to investigate acorn flour (0-30%) and acorn syrup (0-100%) substitutions with wheat flour (cake flour) and sugar respectively on the properties of sponge cake based on combined design. The results showed that replacing acorn flour (AF) with wheat flour increased the dough density and baking loss% and decreased cohesiveness, lightness (L*), and redness (a*). Incorporating acorn syrup darkened the color of the crust. The Moisture content and specific volume were not affected by the replacement of flour and syrup of acorn. Addition of the acorn flour and acorn syrup enhanced water activity, firmness, chewiness, and diminished springiness. Sensory evaluation showed that with the replacement of acorn syrup, the overall acceptability of samples decreased, but acorn flour had no significant effect on it. According to the optimization results, it is suggested to substitute 11% acorn flour along with 25% or 45% acorn syrup to produce a high nutritional product with desirable textural and sensory characteristics.
Volume 21, Issue 154 (12-2024)
Abstract
In addition to the nutrients, acorn fruits contain a large amount of Polyphenolic compounds. For this reason, acorn can be considered as a suitable raw material for making bread and sweets. The use of acorn flour in food products leads to enhancing their nutritional value, creating added value for this forest fruit and then, helps to preserve oak lands and forests. Therefore, the purpose of this research was to enrich bread using acorn flour. So, the effect of replacing 10-30% acorn flour with wheat flour along with 1-4% gluten on the quality characteristics of the produced bread was investigated. Optimization of bread formula was done based on response surface method. The results showed that the use of acorn flour leads to an increase in hardness in bread and the addition of gluten moderates part of this effect. The initial hardness and specific volume of the samples were obtained in the range of 7.31 to 9.1 N and 2.94 to 3.7 cm3/g corresponding to the samples with the lowest and highest amount of acorn flour. The results of image processing of bread crumb showed that with the increase in the percentage of acorn flour usage, the percentage of porosity decreased significantly, although the porosity value was increased by the addition of gluten (p<0.05). It was also found that the addition of acorn flour caused a decrease in the brightness of the crumb and crust of the bread. Finally, the optimized formula with 10% acorn flour and 4% gluten was more accepted by the panel taste, with a score of 4.83, compared to the sample without acorn flour, which scored 4.08. Therefore, it is possible to remove the disadvantages of bread containing oak flour by adding gluten and even achieve bread with a more favorable overall acceptance than wheat bread.
Volume 26, Issue 6 (11-2024)
Abstract
The current research aimed, first, to valorize Tunisian cork oak acorn starch extracted by water soaking method in dairy industry. The effect of its incorporation into milk on the evolution of rheological, sensorial and microbiological properties of stirred yogurt during refrigerated storage was, also, evaluated. No significant effect was observed on fermentation parameters of the acorn starch added product. During 28 days of refrigerated storage, the incorporation of acorn starch did not affect the post-acidification and the viability of the lactic starter cultures. Moreover, the treated stirred yogurt exhibited a lower syneresis value and a higher consistency when compared to the untreated control and that incorporated with industrial modified starch. The findings revealed that acorn starch incorporation extended the shelf life of the final product by about 6 days. Despite its less appreciated color (3.67±0.5), acorn-starch-added yogurt product gained the highest overall acceptability scores (4.11±0.6) by the panel.
