Saeed Mahdavi; Mohammad Hadi Rezvani
Abstract
Kenaf as an industrial plant can play an important role in providing shortage of virgin fiber for paper and board based on the history of cultivation in Iran. Harvesting time of kenaf is one of the most important economic-technical aspect, so the growth rate of kenaf (variety of Cuba) and the weight ...
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Kenaf as an industrial plant can play an important role in providing shortage of virgin fiber for paper and board based on the history of cultivation in Iran. Harvesting time of kenaf is one of the most important economic-technical aspect, so the growth rate of kenaf (variety of Cuba) and the weight ratio of bast, core and pith individually were measured at 5, 6 and 7 months after planting and kenaf biomass was determined after 7 month. Soda-AQ pulping from kenaf bast fiber was adjusted at 14% and 16% chemical charges, 175°C, 120 min., liquor to bast fiber of 5:1 and adding 0.2% AQ. Handsheet was made by the bast pulp from the three harvested times with base weight of 110 g/m2. The results showed that by increasing the harvest period from 5 to 6 and 7 months, stalk height and diameter increased 9% and 5%, and vice versa, respectively. The weight ratio of kenaf bast to core has decreased by increasing of harvest time. Dry and green biomass of kenaf was determined at 33.1 and 7.7 t/ha, respectively. Screen yield, kappa number, and reject were of pulp were measured for combinations of optimal cooking in range of 48.8% to 52.9%, 35.4 to 72.6, and 0.92% to 2.5%, respectively. The beating energy consumption of pulp that prepared from 7 month harvesting time was greater than the others. Optimal conditions were determined as harvesting time of 5 month and cooking variables of 120 min, 165 °C and 16% NaOH for carton top liner. Handmade paper properties compared to kraft liner paper confirms the superiority of paper made from virgin kenaf bast fiber according to national standard of Iran (ISIRI 3054).
Abas Fakhryan; Hossein Hosseinkhani; Fardad Golbabaei; Mohammad mehdi Brazandeh
Abstract
In this Investigation chemical, physical, morphology, pulp and paper making characteristics of Populus costanzo were studied. The average dry and critical specific gravity was found to be 0.39and 0.36 and the fiber morphology including fiber length , diameter ,lumen and thickness ...
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In this Investigation chemical, physical, morphology, pulp and paper making characteristics of Populus costanzo were studied. The average dry and critical specific gravity was found to be 0.39and 0.36 and the fiber morphology including fiber length , diameter ,lumen and thickness of cell wall 1.14 mm,28.84 µm, 28 µm ,and 2.92 µm was determined respectively. The average chemical composition including cellulose 50.74%, lignin 19.18%, Ext. 1.22% and Ash 1.65% were measured. In order to cook and pulping, Kraft process was used. The maximum yield and kappa number of Populus costanzo at 1 hour cooking time, 150°c cooking temperature and 12% effective alkali condition obtained at 61.91% and 54.83 respectively and the minimum yield and kappa number at 3 hour cooking time, 170°c cooking temperature and 16% effective alkali condition obtained at 45.63% and 13.42 respectively.
Pulp and paper
Abdolrahim Mohebalian; Ahmad Jahan latibari; Ajang Tajdini; Shadman Pourmosa
Abstract
In this research, the influence of two temperatures (60 and 90°C) and three dosages of sodium hydroxide (5, 7.5 and 10%, based on the dry weight) on hornbeam wood chips alkaline pre-hydrolysis and soda pulping was studied. Soda pulping of both pre-hydrolyzed and control chips were conducted applying ...
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In this research, the influence of two temperatures (60 and 90°C) and three dosages of sodium hydroxide (5, 7.5 and 10%, based on the dry weight) on hornbeam wood chips alkaline pre-hydrolysis and soda pulping was studied. Soda pulping of both pre-hydrolyzed and control chips were conducted applying constant pulping variables. The effect of pre-hydrolysis on hemicelluloses removal and sodium hydroxide consumption and pulp characteristic including total yield, reject, pulp freeness, kappa number, and pulp strengths were measured and statically analyzed. In case the effect of variable on measured property was statistically significant, then Duncan multiple range grouping of the measured property was arranged. The result revealed that pre-hydrolysis removed almost 4.2% (based on dry wood) of hemicelluloses of the wood and pre-hydrolysis demonstrated easier soda pulping delignification, due to weakening the lignin-carbohydrate bonds and both total yield, reject and kappa number were reduced. Tensile strength index of the pulp produced using pre-hydrolyzed chips war lower and as the dosage of sodium hydroxide increases, the tensile strength index was reduced initiated from the removal of hemicelluloses which is also lower than control pulp, Tear strength index of the soda pulp from pre-hydrolyzed chips was mildly reduced which is anticipated to be the consequence of fiber weakening and fiber breaking during cooked chips defibration. The effect of pre-hydrolysis variables on tear strength was not statistically significant. Based on the result of this study, hornbeam wood can be a potential source of bio-refining based on lignocellulosic material.
Management and Economics wood
Azar Haghighi Poshtiri; Mehdi Jonoobi; Ali Naghi Karimi
Abstract
Cellulose nanocrystals (CNC) are new class of cellulose materials that find wide applications in various research areas over the past two decades. These nanoparticles are usually made by acid hydrolysis of cellulose substances such as wood, cotton, Starch etc. The main aim of this study is to find the ...
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Cellulose nanocrystals (CNC) are new class of cellulose materials that find wide applications in various research areas over the past two decades. These nanoparticles are usually made by acid hydrolysis of cellulose substances such as wood, cotton, Starch etc. The main aim of this study is to find the optimal conditions for obtaining an aqueous stable colloid suspension of cellulose nanocrystal (CNC) from α-cellulose with a high-yield procedure. Therefore various conditions of acid hydrolysis were evaluated as reaction temperature and reaction time. The percentage of yield was calculated for all suspensions. The morphology of the prepared CNC was characterized by Transmission Electron Microscopy (TEM), Environmental Scanning Electron Microscopy (ESEM) and the crystallinity was measured by X-ray diffraction (XRD). The results showed that highest yield of CNC (88%), was achieved from the reaction condition of 60 minutes at 60 °C. Generally, rod-like shape crystals achieved from α-cellulose with an average size of 35-50 nm and high crystallinity (92%) can be make it to a convenient and competitive source for the production of cellulose nanocrystal for various industries.
Pulp and paper
Hosein Valayi; Ahmad Jahan Latibari
Abstract
Strength properties and the yield of soda and soda-ethanol pulps produced using hornbeam, beech and poplar woods were investigated. Soda pulps were produced applying 20% active alkali and the soda-ethanol pulps were made using 10% active alkali and 50% ethanol. The pulping temperature was constant at ...
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Strength properties and the yield of soda and soda-ethanol pulps produced using hornbeam, beech and poplar woods were investigated. Soda pulps were produced applying 20% active alkali and the soda-ethanol pulps were made using 10% active alkali and 50% ethanol. The pulping temperature was constant at 175 C and the soda pulping time was selected at 120 minutes and the soda-ethanol pulping times were 120 and 180 minutes. The highest accepted pulping yield at 58.54% was reached using soda pulping on poplar wood and the lowest yield (49.29%) was related to soda-ethanol pulp produced from beech wood applying 180 minutes pulping time. The accepted yield of soda-ethanol pulping was low, but the kappa numbers of these pulps were almost 20 units lower than soda pulps. The strength properties of soda-ethanol pulps were superior to soda pulps and the difference was statistically significant at 99% confidence level. The results of this study indicated that the delignification of soda-ethanol pulping process is faster than soda pulping from the selected hardwoods especially poplar wood.
Pulp and paper
Afshin Veisi; Saeed Mahdavi; Mohammad Talaeipoor
Abstract
In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals ...
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In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals charge and 10:1 cooking liquor and straw ratio. The yield after defibration treatment varied between 56.5% and 72.5%. Two optimum pulps bleached by TCF method applying 2% and 3% NaOH, 1.5% and 2% H2O2, and 60 and 120 minutes bleaching time. One way analysis variance method showed that bleaching time had the most significant effect on optical properties of handsheet. Applying 3% (based on oven dry weight of the unbleached pulp) NaOH, 2% H2O2, and 120 min. in bleaching improved the brightness and opacity to 52.9%, and 79.5% ISO, respectively. Optimum pulp strengths including tensile, burst and tear indices were measured 43.87 Nm/g, 2.18 kPa.m2/g, and 8.46 mN.m2/g, respectively. All the strengths were higher than newsprint paper strength produced by Mazandaran wood and paper and Korean companies.
Pulp and paper
Seyed_Pedram Hashemi; Asghar Tabei; Seyyed Peyman Hashemi
Abstract
In this study the effect of different values of peroxide in three levels 3%, 4%, 5% and sodium hydroxide in two levels 2%, 3%, on bleaching of tobacco stalks ( Nicotiana tabacum L. 'PVH 19') soda pulp was investigated. Tobacco stalks were soda pulped using 22% alkali in 170°C for 100 minutes. Produced ...
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In this study the effect of different values of peroxide in three levels 3%, 4%, 5% and sodium hydroxide in two levels 2%, 3%, on bleaching of tobacco stalks ( Nicotiana tabacum L. 'PVH 19') soda pulp was investigated. Tobacco stalks were soda pulped using 22% alkali in 170°C for 100 minutes. Produced pulp had 37.1 % yield and kappa number 62. Bleaching process included two stages: chelating and alkali peroxide bleaching. Results indicated that brightness increased and kappa number decreased by increasing sodium hydroxide and peroxide Hydrogen level.The data related to 3% caustic soda and 5% peroxide treatment without chelating stage, indicated that initial chelating stage significantly affected on the brightness, kappa number and yield of the bleached pulp, and this treatment had the lowest brightness and the highest kappa number and yield among all treatments. Finally, 3% caustic soda-5% peroxide treatment with initial chelating stage had the highest brightness (44.50%) and the lowest yield (83.20%), was selected as the best treatment.
Mahid Farzi; Ali akbar Enayati; Davood Parsa paghoh
Abstract
In this investigation, soda pulps from old rags applying three pulping times (60, 120 and 180 minutes ) and three levels of active alkali ( 6,8, and 10% NaOH based on OD weight of rag) and pulping temperature of 125º C were produced. Liquor to rag ratio was kept constant at 11:1(based on the ...
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In this investigation, soda pulps from old rags applying three pulping times (60, 120 and 180 minutes ) and three levels of active alkali ( 6,8, and 10% NaOH based on OD weight of rag) and pulping temperature of 125º C were produced. Liquor to rag ratio was kept constant at 11:1(based on the weight of the rag). After pulping, hand sheets were made and then both strength and optical properties of hand sheets were measured. It was revealed that, the optimum condition for rag pulping was; 8% active alkali and 120 minutes. At this pulping conditions, the pulping yield and mechanical and optical properties of pulp were measured as yield; 86.46 %, tear index; 20.12 mN.m2/g, burst index; 2.09 kPa.m2/g, breaking length; 1.96 km, brightness; 95.86 % and opacity: 96.39
Jafar Ebrahimpour Kasmani; Mohammad Talaeipoor; Amir homan Hamasi; Ahmad Samariha
Abstract
The strength properties of paper produced from pulp obtained after 1, 2 and 4 weeks treatment of hornbeam chips with the Phanerochaete chrysosporium BKM - 1767 fungus was evaluated and compared with control samples. After preparing fungal specimens, hornbeam chips were exposed to this fungus for one ...
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The strength properties of paper produced from pulp obtained after 1, 2 and 4 weeks treatment of hornbeam chips with the Phanerochaete chrysosporium BKM - 1767 fungus was evaluated and compared with control samples. After preparing fungal specimens, hornbeam chips were exposed to this fungus for one of the three periods of 1, 2 and 4 weeks at 39oC temperature and 65% relative humidity. Then CMP pulp was prepared using treated chips, chemical treatment temperature of 165oC, for either 80 or 90 minutes and sodium sulfite charge of 14, 18 and 22% (based on oven dry weight of the wood). The liquor to chips was constant at 7 to 1. The results showed that the CMP pulping yield from treated chips was lower than control sample and the reduction after treatments for 1, 2 and 4 weeks was almost 1.64, 2.84, 6.20 percent respectively. Also the strength indices of paper such as tensile strength, burst strength, tear strength and folding endurance paper prepared from treated chips were lower than control chips
Sabah Ashrafi birghani; Ahmadreza Sraeyan
Abstract
The purpose of this study was to compare the effects of various concentrations of sodium hydroxide and treatment times on the properties of bagasse and Eastern cottonwood (Populus deltoids) cold soda pulp and paper. The cold soda pulp was prepared using various concentrations of sodium hydroxide (5, ...
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The purpose of this study was to compare the effects of various concentrations of sodium hydroxide and treatment times on the properties of bagasse and Eastern cottonwood (Populus deltoids) cold soda pulp and paper. The cold soda pulp was prepared using various concentrations of sodium hydroxide (5, 10, 15% based on oven dry weight), different treatment times (20, 40, 60 min.), and constant liquor to wood ratio of 10:1 at 25 ºC and atmospheric pressure. The pulp prepared after 40 min treatment time was selected and refined to the freeness of 400 ml CSF. Analysis of the properties of hand sheets was conducted based on completely randomized design. Duncan multiple range grouping test was used to classify the properties of papers. The results indicated that, the yield of pulp obtained from Eastern cottonwoodand bagasse pulp varied between 86.54% to 94.52% and 70.65 to 87.32% respectively. The absorbed alkali was varied from 2.15% to 4.78 % for Eastern cottonwood and 3.06% to 6.80% for bagasse. Eastern cottonwood had the highest yield, thickness and strength properties whereas the highest absorbed alkali and paper density were observed in bagasse. It was observed that as the concentration of sodium hydroxide was increased from 5% to 15%, the yield of pulp and the thickness of paper decreased, while the absorbed alkali, density and the strength properties of paper increased. In general, the cold soda pulp from Eastern cottonwood provided higher quality compared with bagasse under the same pulping conditions.
Pulp and paper
Maryam Rostaei; Rabi Behroz; Saeid Mahdavi
Abstract
This research was performed to improve the properties of the pulp made of Aspen Deltoides, using antraquinone(AQ) catalizer. Neutral sulfite semichemical (NSSC) method in three efficiency levels of 55, 60, and 65% was applied. Cooking situations was selected as: Specific Temperature (175˚ C) , Time ...
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This research was performed to improve the properties of the pulp made of Aspen Deltoides, using antraquinone(AQ) catalizer. Neutral sulfite semichemical (NSSC) method in three efficiency levels of 55, 60, and 65% was applied. Cooking situations was selected as: Specific Temperature (175˚ C) , Time (Variable) , Specific Percentage of Chemicals 14% and Anthraquinone 0.1% . In all stages of cooking, weight ratio of sodium sulfide to sodium bicarbonate was set as 4.5/1. The ratio of cooking liquid to chips was 5/1. The results indicated that AQ causes an increase in efficiency and a significant decrease in Kappa. Researches also indicated that by the use of AQ, strength indexes of the paper such as strength of burst, tearing, tensile, Ring Crush Test and Corrugating Medium Test increases. Optical experiments on hand sheets following addition of AQ, indicated increase in brightness and decrease in opacity.
Pulp and paper
Ahmad Jahan latibari
Abstract
In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping ...
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In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping temperature were used. After digester yield varied between 64.65 and 71.7% and the total yield after defibration was measured as 54.45% and 62%. Unrefined pulp freeness varied between 708 and 765 ml CSF. Pulps produced applying 10-16% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected from further evaluation. These pulps were refined to about 365 ml CSF in a PFI mill and then handsheets were made for strength evaluation. The apparent density of the handsheets varied between 437-488 kg/m3, tear index between 6.51-7.11 mN.m2/g, and tensile index between 29.2 -30.8 N.m/g. Significant difference at 99% was not observed between the strength of the pulps. Then pulp produced applying 10% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected for bleaching trials. Totally Chlorine Free (TCF) bleaching sequence was used for bleaching the selected pulp. Pulps bleached applying 4% H2O2 and 3.5% NaOH, 3% sodium Silicate, 0.5% MgSO4 and 0.3% DTPA for 2 hours showed the highest brightness of 50.69% compared to 29.2% for unbleached pulp.
Pulp and paper
Mohammad taghi Asdolah zadeh; Hossein Resalti; Ali Ghasemian
Abstract
In the present study the effects of hot water pre-extraction and alkaline catalyzed were evaluated on soda-aq pulping of kenaf whole stem. In this respect, following kenaf chips pre-extraction at various temperature and time conditions, pulp preparation were carried out on oven-dried weight loss levels ...
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In the present study the effects of hot water pre-extraction and alkaline catalyzed were evaluated on soda-aq pulping of kenaf whole stem. In this respect, following kenaf chips pre-extraction at various temperature and time conditions, pulp preparation were carried out on oven-dried weight loss levels of 8.5, 11.5 and 14.5 % of the samples, and the reference untreated kenaf chips performed by using Soda-AQ at 3 levels of H-factors ( 983, 1408 and 1832 hours). Results indicated that kenaf chips weight losses increased while the pre-extracted pH decreased as pre-extraction temperature and time increased. The required H-factor for achieving certain level of weight loss was reduced by adding small amounts of alkali (0.15 % on oven dried kenaf) on hot water extraction stage. The Pulp yields were reduced by increasing cooking H-factor and extracted weight loss. Averages comparison indicated that significant differences were observed, at 95% confidence, between the pulp yield and kappa number from reference pulp and pre-extracted pulp samples at levels of about 8.5, 11.5 and 14.5 %, and pulp yields and their kappa number were higher in reference pulps than pre-extracted samples. In addition, pulp yield average was higher in pre-extracted samples by alkaline catalyzed than pre-extracted samples by hot water, however, no significant differences were observed between their kappa number average. Meanwhile, to obtain a certain (similar) kappa number, pre-extracted kenaf chips in comparison with reference untreated kenaf chips require lower H-factor.
Pulp and paper
Davod Efhami; Mohammad reza Dehghani
Abstract
In this work effect of initial alkali charge were investigated on the yield and kappa number of soda beech pulp and alkali consumption pattern. The results indicated that, the regression models are useful for studying the relations between yield, kappa number and alkali consumption. Soda cooking was ...
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In this work effect of initial alkali charge were investigated on the yield and kappa number of soda beech pulp and alkali consumption pattern. The results indicated that, the regression models are useful for studying the relations between yield, kappa number and alkali consumption. Soda cooking was performed in 30, 40, 50, 60 and 70 gr.lit-1 initial alkali concentration and five different cooking times. The chips dimensions were in the range of 3-5 cm length, 1-2 cm width and 0.05 cm thickness. The results showed that increasing of alkali charge decreased the time of cooking in the same yield or kappa number. Deligninifaction decreased significantly in kappa number lower than 30. In the same kappa number, increased alkali charge gave a lower yield. The alkali consumption was regularly decreased with increasing of initial alkali charge from 30 to 70 gr/lit, but alkali charge consumption pattern varied in less and more than 30 kappa numbers.
Pulp and paper
Saeid Kamrani; Ahmad reza Saraeyan; Eyman Akbarpoor
Abstract
In this study, mechanical and optical properties of CMP, one stage APMP and two stage APMP pulps ( from Tajan wheat straw Golestan province ) were investigated. wheat straw collected at research center of Agriculture and Natural resources of Golestan province. Fiber dimensions such as average fiber length ...
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In this study, mechanical and optical properties of CMP, one stage APMP and two stage APMP pulps ( from Tajan wheat straw Golestan province ) were investigated. wheat straw collected at research center of Agriculture and Natural resources of Golestan province. Fiber dimensions such as average fiber length , diameter cell , lumen and fiber wall thickness were assessed at 1.18mm, 18.156, 11.461 and 3.396 microns, respectively. chemical components such as cellulose , lignin , ash and extractives were assessed at 53.7, 21.1, 5.1 and 8.5 percent, respectively. Based on the preliminary experiment results, impregnation temperature was 950C, impregnation times of 10, 20, 30, 40 minutes, caustic charge 10% and peroxide charge was 3% in CMP ,one stage APMP and two stages APMP pulps. Considering pulp properties and treatment conditions, many treatments including 20 and 40 minutes treatments were selected for making of handsheet. The selected pulps were refined up to 350 ml (CSF) freeness prior to making of hasndsheet. Final results indicated that two stages APMP pulp (impregnation in time 40 minutes) had the highest burst strength, breaking length and brightness. Also, the results of yield and tear strength showed that, there was no meaningful difference at the 5% level between three methods CMP, one and two stages of APMP pulps.
Physics and Mechanical Wood
Shamohammad Amiri
Abstract
Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl ...
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Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl coefficient were calculated at 34.28, 67.14 and 48.93 respectively.Chemical composition of cotton stalk was determined at 47.83%cellulose, 21.66% lignin, 2.13% alcohol-acetone extractives and 2.83% ash.Soda pulping at following variables was investigated. Three levels, of cooking temperature (140, 160 and 180 degree Celsius), three cooking time (30, 40 and 50 minutes) and raw material condition (normal and debarked stalks). Active alkali of 20% (based on NaOH) and liquor to wood ratio of 5: 1 were kept constant for all soda cooks. The optimum combination of variables160 degree Celsius I temperature, 40 minutes time and debarked raw material. The yield and kappa no. of pulp obtained at this cooking condition was 50.4% and 89.15 respectively.
Pulp and paper
Abbas Fakhryan roghani; Abdolrahman Hosseinzadeh; Fardad Golbabaei
Abstract
In this investigation, physical, chemical, fiber dimensions, pulp and papermaking characteristics of 4 years old Alnus glutinosa was researched. The average of oven dry and critical density, fiber length, fiber diameter, lumen diameter and cell wall thickness were measured at 0.396, 0.368, 0.875mm, 32.66um, ...
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In this investigation, physical, chemical, fiber dimensions, pulp and papermaking characteristics of 4 years old Alnus glutinosa was researched. The average of oven dry and critical density, fiber length, fiber diameter, lumen diameter and cell wall thickness were measured at 0.396, 0.368, 0.875mm, 32.66um, 27.28 urn and 2.70 urn respectively. Chemical compositions were obtained 48.5% cellulose, 25.35% lignin, 0.31% ash and 2.36% extractives. CMP, one stage APMP and two stage APMP processes were used for cooking. After preliminary cooking, cooking temperature, cooking time, NaOH and H202 charges were applied at 95 degree of centigrade, 10, 20, 30 and 40 minutes 10%,3% and so on. In CMP process, the average of yield, burst index, breaking length, tear index opacity and brightness were obtained at %73.72-%82.57, Kpa m2/gr. 1.53, Km 3.81, mNm2/gr 3.34, %99.59 and %29.35 correspondingly.In one stage APMP process, the average of yield, burst index, breaking length, tear index opacity and brightness were obtained at %74.09-%81.57, Kpa m2/gr. 1.52, Km 3.5, mNm2/gr3.2, %99.80 and%28.21 respectively.In two stage APMP process, the average of yield, burst index, breaking length, tear index opacity and brightness were obtained at %73.99-%80.89, Kpa m2/gr. 1.92, Km 3.95, mNm2/gr 3.45, %99.85 and %32.41 in that order.Among yields of pulp in the three methods, there weren't significant difference at level 5%. In two stages APMP paper, the burst index, breaking length and brightness were more than other and changes of cooking methods hadn't significant differences at level 5% on tear index.
