PROCESSING AND PRODUCTS
Effect of Meat Temperature on Proteins,Texture,and Cook Loss for
Ground Chicken Breast Patties 1
R.Y.Murphy and B.P.Marks 2
Department of Biological and Agricultural Engineering,University of Arkansas,Fayetteville,Arkansas 71701
ABSTRACT Soluble proteins,myo?brillar proteins,col-lagen,texture,and cook loss were evaluated at different meat temperatures by heating ground and formed chicken breast meat in brass containers in a water bath to temperatures of 40,50,60,70,or 80C.The soluble proteins decreased by approximately 90%as meat tem-perature increased from 23to 80C.The myo?brillar pro-tein subunits of molecular weight greater than 43kDa decreased with increasing temperature from 23to 80C
(Key words :texture,protein,thermal processing,cook loss,poultry)
2000Poultry Science 79:99–104
INTRODUCTION
When manufacturing precooked meat products,process temperatures strongly in?uence texture,protein changes,cooking yield,and other important quality factors such as juiciness,color,and ?avor (Bertola et al.,1994;Bouton et al.,1981;Dumoulin et al.,1998;Martens et al.,1982;Paul,1963).The relationships between processing temperature and these quality factors are important in improving the design and operation of thermal processes for foods (Rao and Lund,1986).
For example,heating temperatures have been shown to affect the texture of beef muscle.Bramblett et al.(1959),Marshall et al.(1960),and Pen?eld and Meyer (1975)be-lieved that a lower cooking temperature yielded a more tender product with lower cooking losses.Davey and Gil-bert (1974)evaluated the relationship between texture and heating temperature using small beef samples and found that the texture varied in a temperature range of 40to 75C.Machlik and Draudt (1963)studied the effect of heating temperature on changes in force required to shear small cylinders of beef and found a decrease in toughness from 58to 60C and an increase from 65to 75C.
Texture changes during processing are a result of com-plex chemical changes (Barrett et al.,1998;He and Sebranek,1996;DeFreitas et al.,1997;Rao and Lund,1986)related
Received for publication June 8,1998.Accepted for publication August 11,1999.1
Published with the approval of the Director,Arkansas Agricultural Experiment Station,manuscript No.98054.2
To whom correspondence should be addressed:marksbp@https://www.doczj.com/doc/1710548876.html,.
99
as analyzed via SDS-PAGE.Amount of soluble collagen more than doubled when meat temperature was in-creased from 50to 70C.The maximum peak shear force was obtained,via Warner-Bratzler shear test,at 60C for ground chicken breast patties.The weight of patties de-creased approximately 10.3%when meat temperatures were increased from 23to 80C.Overall,heating tempera-ture affected the texture of the meat and caused changes in proteins and cook loss.
primarily to the muscle ?bers (Rowe,1974)and connective tissue ?bers (Hearne et al.,1978).The relationship between texture and heat-induced denaturation of meat protein has been reported for beef (Martens et al.,1982;Findlay et al.,1986;Bertola et al.,1994).Temperature also affects the solu-bility of the meat proteins (Bouton and Harris,1972).How-ever,results for heat-induced changes of connective tissue in relation to texture vary (Hearne et al.,1978),and con?ict-ing explanations have been given for the relationship be-tween texture and protein changes during thermal pro-cessing of beef muscles (Bailey,1984;Laakkonen et al.,1970;Bertola et al.,1994;Paul et al.,1973;Bouton and Harris,1972;Bouton et al.,1974;Bailey,1984).The texture of cooked meat is generally considered to be affected by heat-induced changes in connective tissue,soluble proteins,and myo?-brillar proteins.The cross-linkage between the collagen molecules within the connective tissue is associated with collagen solubility (Zayas and Naewbanij,1986).Changes in collagen solubility during heating could signi?cantly in?uence the texture of poultry meat (Zayas and Naew-banij,1986).
The Warner-Bratzler shear test is commonly used for determining meat texture (Lanari et al.,1987;Zhang and Mittal,1993).Bouton and Harris (1972)used peak shear forces from Warner-Bratzler tests to relate texture to changes in meat proteins.When there are large differences in collagen content (connective tissue)among meat sam-ples,Warner-Bratzler shear force has correlated poorly with the texture assessment (Pen?eld and Meyer,1975).How-
Abbreviation Key:MSE =mean standard error.
MURPHY AND MARKS 100
ever,chicken breast muscle contains a low level of collagen (Dawson et al.,1991).
Collagen is distributed in a?ne state of subdivision throughout the muscle,and changes in connective tissue during cooking are important to meat quality(Winegarden et al.,1952).Although the collagen content of ground chicken breast patties is low in comparison to that of the various beef muscles evaluated by other researchers (Hearne et al.,1978;Bertola et al.,1994;Paul et al.,1973), changes in collagen solubility with heating temperature could still affect the textural and water-binding properties of the product(Eilert and Mandigo,1993).
Heat-induced changes in protein solubility also relate to changes in water-holding capacity of meat(Bouton and Harris,1972).Because of protein changes with heating, water content within the meat myo?brils in the narrow channels between the?laments changes as meat shrinks within the tissue matrix(Bertola et al.,1994),resulting in cook loss with heating.Meat can shrink in two dimensions (length and width)and expand in the third dimension (Offer et al.,1984;Rowe,1974).The extent of meat shrinkage and expansion varies with different muscles and the meat temperature(Winegarden et al.,1952).The change in water content also contributes to changes in sarcomere length and juiciness with temperatures(Laakkonen et al.,1970; Bouton et al.,1975).
Most previous reports have focused on the effects of heat treatment on the structure of muscle?bers in relation to the texture of beef(Bertola et al.,1994;Yu and Lee,1986; Zayas and Naewbanij,1986).Limited publications have been found on the effects of thermal processing on the texture of chicken(Dawson et al.,1991)and chicken prod-ucts.The objective of this study was to evaluate changes in proteins,texture,and mass of ground chicken breast patties at different meat temperatures.
MATERIALS AND METHODS Approximately5kg100%ground and formed chicken breast patties(114.3mm diameter×14.8mm thick;average, 53g)were obtained from a commercial processor.For prox-imate analysis,six original patties were tested.For the ther-mal treatments,the original patties were cut into smaller patties(50.8mm diameter×14.8mm thick).For each ther-mal treatment,21of these samples were individually pro-cessed.From these processed samples,12were used to analyze cook loss.Then,a smaller(25.4mm diameter)disc was bored,with a boring device,from the center of each of the21samples.From these21discs,12were used for texture analyses,three were used for the analyses of soluble proteins and SDS-PAGE,and six were used for collagen solubility analyses.For the uncooked meat,six patties were used for the analyses of soluble proteins,SDS-PAGE,and collagen solubility;12other raw patties were also subsam-pled via a25.4mm-diameter boring device and used for texture analysis.
3Sigma Chemical Co.,St.Louis,MO63178.Sample Composition
Proximate analyses on the chicken patties were carried out per AOAC procedures in sections950.46B,981.10, 985.15,and900.02A(AOAC,1990).The total water content was78.6±1.2%(w/w,wet basis),using an oven drying method at110C for24h.The total protein content was 95.2±0.6%(w/w,dry basis),using the Kjeldahl method. The total lipid content was0.15±0.08%(w/w,dry basis), using the Soxhlet method.The total ash content was2.1±0.3%(w/w,dry basis),using a gravimetric method by heating the sample at550C in a muf?e furnace for24h. Temperature Treatment
Prior to the thermal treatments,the original meat patties were cut into discs(50.8mm diameter×14.8mm thick), placed into a brass container(51mm diameter×15.0mm height×0.038mm wall thickness),and immersed in a thermostatic water bath(±0.1C)at a temperature of40, 50,60,70,or80C.Temperature was monitored at the center of the sample via a Type E thermocouple.The treatment was stopped when the meat center differed<0.2C from the bath temperature(within17to20min).After each heat treatment,samples were removed from the thermostatic bath and cooled by immersing the sample container in an ice-water bath until the sample center reached23C(within 3to4min).During each experiment,thermocouples were also used to monitor the temperatures of the sample sur-face,the midpoint between the center and the surface,and both water baths(heating and cooling).
The thermally processed samples were allowed to equili-brate at ambient temperature for15min prior to the analyti-cal procedures for cook loss and texture.The samples for soluble proteins,SDS-PAGE,and collagen analyses were placed in a freezer(?20C)immediately after the thermal treatments and subsequently analyzed within3d. Soluble Proteins
Both cooked and uncooked meat samples were freeze-dried,ground,and dissolved in a0.05M potassium phos-phate buffer solution with0.1M NaCl,5m M EDTA,and 1m M NaN3at pH7.4(Lan et al.,1995).The sample solution (2%,w/v)was gently shaken on an oscillator for approxi-mately16h to allow a complete extraction and then centri-fuged for～1min at8,000×g.Soluble proteins were deter-mined by analyzing the supernatant using the Bradford method(Bradford,1976)and expressed as a percentage of the total soluble proteins in the sample(w/w,dry basis). Bovine serum albumin3was used as the protein standard. Sodium Dodecyl Sulfate-Polyacrylamide
Gel Electrophoresis
Cooked and uncooked meat samples were freeze-dried and subjected to SDS-PAGE(sodium dodecyl sulfate-poly-acrylamide gel electrophoresis),according to the proce-dures described by Claeys et al.(1995).Protein solutions of
PROTEINS,TEXTURE,AND COOK LOSS IN CHICKEN101
0.1%(w/v)were obtained by dissolving the meat samples in10%SDS solution.After mixing with the loading buffer at a ratio of1:3(sample solution:loading buffer),10μl of each protein solution were loaded on a4to20%acrylamide gel.The molecular weights of the protein subunits were determined using a densitometer by the comparison of their relative mobilities of migration with those of protein molecular weight standards(high range molecular weight standards4for SDS-PAGE).
Collagen Solubility
Prior to collagen analysis,cooked and uncooked samples were thawed in the refrigerator(4C)for8h and then allowed to equilibrate at ambient temperature for30min. The effect of meat temperatures on the connective tissue of the ground chicken breast patties was determined by the hydroxyproline solubility in the samples(Pool,1967). Meat samples(6g)were treated according to the prepara-tion procedures of Eilert and Mandigo(1993)for analyzing the soluble and insoluble collagen in meat products.The soluble and insoluble hydroxyproline contents were deter-mined using the rapid procedure of Bergman and Loxley (1963).Collagen values were expressed as milligrams colla-gen per gram sample(wet basis),using hydroxyproline conversion values of7.25and7.52for insoluble and soluble collagen,respectively.Solubility of collagen,which re?ects the degree of collagen crosslinking,was expressed as a percentage of the soluble collagen in the total collagen (w/w).
Texture
The Warner-Bratzler shear test(Lyon et al.,1998)was used to evaluate the texture of the ground chicken breast patties after thermal processing.Mechanical properties of the meat were tested by Warner-Bratzler shear on a univer-sal testing machine,5with a shear speed of40mm/min. The shear blade was applied perpendicularly to the disc axis,and peak force was determined as the maximum force during shearing.
Cook Loss
After heating,samples were removed from the container, blotted with a paper towel,and weighed to determine the cook loss.The mass changes were expressed as a percentage of initial mass(w/w,wet basis).Because the change in water content was evaluated with relatively small samples (30g),the data obtained in this study would not fully represent the water diffusion that might occur in larger meat products or in different cooking environments.None-theless,the comparative study of mass change as presented in this study should still yield insight about the ability of the meat to hold water after various heating treatments.
4GIBCO Life Technologies,Rockville,MD20850.
5Instron Corporation,Canton,MA
02021.
FIGURE1.Example of thermal history of chicken breast patties(n =21)at a bath temperature of50C for the sample surface,center,and midpoint between the surface and center.
Overall Statistics
For soluble proteins,collagen,toughness,and cook loss, averages and standard deviations were computed from3, 6,12,and12samples,respectively,at each temperature treatment.Analyses of variance and correlation analyses were performed among meat temperature,soluble pro-teins,soluble collagen,peak force,and cook loss.Model ?tting was conducted using standard least squares.Statisti-cal evaluation was performed via SAS software(SAS Insti-tute,Inc.,Cary,NC,1998).For SDS-PAGE,based on the comparison analysis using a densitometer,the elec-trophretic results were identical in all runs(n>6)for the samples with the same temperature treatments.
RESULTS AND DISCUSSION Thermal History
Meat samples were processed until center temperatures were in equilibrium with the bath temperature(i.e.,within 0.2C),which ensured that the?nal temperature pro?le was uniform within the sample(Figure1).
Soluble Proteins
The total soluble proteins decreased(P<0.0001)with increasing meat temperatures(Table1).At40,50,60,70, and80C,the total soluble proteins in the ground chicken breast patties decreased9.7,39.0,79.5,88.2,and89.7%, respectively,relative to the raw patties.These results agreed well with previous studies(Murphy et al.,1998;Bouton and Harris,1972).Murphy et al.(1998)observed several endothermic transitions in a range of58.7to78.5C for the sarcoplasmic proteins in chicken breast patties.Bouton and Harris(1972)found that the sarcoplasmic proteins in beef were almost completely denatured at62C and above.
MURPHY AND MARKS
102TABLE 1.Changes in ground chicken breast patties after
heating to different temperatures
Soluble proteins Soluble collagen Cook loss Temperature (%,w/w,dry (%,w/w total Peak force (%,w/w,wet (C)basis)collagen)(N)basis)23119.5(0.4)2 5.9(0.1) 6.8(0.8)none 4017.6(0.5)7.6(0.1) 6.9(0.3) 2.9(0.1)5011.9(0.6)9.0(0.2)10.4(0.5)7.3(0.2)60 4.0(0.2)18.3(0.1)17.6(0.8)8.8(0.1)70 2.3(0.1)20.3(0.5)17.3(0.2)8.9(0.1)80
2.0
(0.1)
21.8
(0.3)
15.1
(0.3)
10.3(0.3)
1Uncooked patties after equilibration to room temperature.2
Numbers in parentheses are standard deviations.
Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis
In the study of Lan et al.(1995),skeletal muscle myosin had a molecular weight of 480kDa,with two large subunits (heavy chains)and four small subunits (light chains).Each heavy chain had a molecular weight of 200kDa,and the light chains had molecular weights of ～16to 27.5kDa.Actin was in its monomeric form of G-actin with a molecu-lar weight of 42kDa.In our study,SDS-PAGE demon-strated that the protein subunits with a molecular weight greater than 40kDa decreased with increasing cooking temperature (Figure 2).Two endothermic transitions,as evidenced by differential scanning calorimetry (DSC),were observed in the ranges of 31.8to 35.0C and 50.9to 54.1C for the myo ?brillar proteins in chicken breast patties (Murphy et al.,1998).Those endotherms were assumed to correspond to protein denaturation and are consistent with the SDS-PAGE results from this study.The 200-kDa band decreased in the meat samples at 40C,and the 43-kDa band decreased in the meat samples at 60
C.These two
FIGURE 2.SDS-PAGE of the ground chicken breast patties.a)Stan-dard;b)raw ground chicken breast patties;c,d,e,f,and g are patties cooked to 40,50,60,70,and 80C,respectively.
bands corresponded to the myosin heavy chain and actin in myo ?brillar proteins,respectively (Claeys et al.,1995).At 80C,the major remaining bands were at molecular weights of <38kDa.
Our results could be explained as increasing cooking temperature resulting in fragmentation of muscle proteins with higher MW.Similarly,disintegration,shortening,and unfolding of protein polypeptide chains have also been observed in heated beef samples (Hearne et al.,1978;Dube et al.1972)and pork samples (Zayas and Naewbanij,1986).
Collagen Solubility
Collagen content in the ground chicken breast patties was 3.0±0.6mg/g (w/w,wet basis).Soluble collagen in the uncooked ground chicken breast patties was 0.18±0.05mg/g sample (wet basis).Amount of soluble collagen increased (P <0.0001)with increasing meat temperature from 50to 70C (Table 1).This result agreed with that of Murphy et al.(1998),in which an endothermic transition was observed at a temperature range of 59.6to 68.4C for collagen in chicken breast patties.Similar results were also obtained by Winegarden et al.(1952)for strips of collage-nous material heated in distilled water.
Texture
Meat temperature affected (P <0.0001)the texture of the ground chicken breast patties as indicated by peak force (Table 1).From 40to 60C,the peak force for the ground chicken breast patties increased approximately 150%.In contrast,the peak force decreased 14.2%with increasing temperature from 60to 80C.These changes in texture with meat temperatures could be affected by changes in the soluble proteins,myo ?brillar proteins,and connective tis-sue of the ground chicken breast patties.
Heating produced a softening of connective tissue caused by conversion of collagen to gelatin and a toughening of meat ?bers caused by heat coagulation of myo ?brillar pro-teins (Bouton and Harris,1972).From past studies in beef,it was suggested that meat texture increased with fragmen-tation of myo ?brillar proteins (Paul,1963;Laakkonen et al.,1970;Bailey,1984;Davey et al.,1976)and decreased with increasing collagen solubility (Rao and Lund,1986;Zayas and Naewbanij,1986;Davey and Gilbert,1974).Myo ?bril-
PROTEINS,TEXTURE,AND COOK LOSS IN CHICKEN
103
TABLE 2.Parameter estimates for peak force and cook loss
Response Term Estimate SE P value Lower 95%Upper 95%Peak force 1
a 117.70340.6854<0.000116.233419.1733
b 1?1.86360.1892<0.0001?2.2694?1.4578
c 10.29500.0440<0.00010.20060.3895
d 1?0.00320.0005<0.0001?0.0043?0.0022Cook loss 2
a 27.66920.4649<0.0001 6.67838.6602c 2?0.11920.0037<0.0001?0.1271?0.1113d 2
0.0022
0.0001
<0.0001
0.0019
0.0025
1
For peak force:R 2=0.9858,mean square error (MSE)=0.485.The a 1,b 1,c 1,and d 1are the coef ?cients for the intercept,soluble proteins,soluble proteins ×collagen,and temperature ×soluble proteins ×collagen terms,respectively.2
For cook loss:R 2=0.9858,mean square error (MSE)=0.230.The a 2,c 2,and d 2are the coef ?cients for the intercept,soluble proteins ×collagen,and temperature ×soluble proteins ×collagen terms,respectively.
lar protein shortening during heating could also result in increasing toughness in chicken (Dawson et al.,1991).In this study,the maximum peak force value was at ～60C,at which drastic changes occurred in soluble proteins,colla-gen solubility,and myo ?brillar proteins (Table 1and Figure 2).These results suggested that texture of the ground chicken breast patties could be attributed to a combined effect of soluble proteins,myo ?brillar proteins,and https://www.doczj.com/doc/1710548876.html,rick and Turner (1992)stated that collagen began to shrink at 60to 70C and was converted to gelatin at 80C and that these changes weakened the connective tissue.Therefore,the reduction in toughness above 60C could also be due to the increase in collagen solubility,as reported by Rao and Lund (1986)and Zayas and Naewbanij (1986).From statistic analysis,a linear model of y 1=a 1+b 1x 2+c 1x 2*x 3+d 1x 1*x 2*x 3+ε1was obtained with R 2=0.9819and mean standard error (MSE)=0.485.In this model,y 1is peak force;x 1is temperature;x 2is soluble proteins;x 3is collagen;a 1,b 1,c 1,and d 1are estimated coef ?cients;and ε1is the error term (Table 2).Therefore,the texture of chicken breast meat is signi ?cantly in ?uenced by soluble protein;the interaction of soluble proteins and collagen;and the interaction of temperature,soluble proteins,and collagen.
Cook Loss
Increasing temperature causes denaturation of myo ?-brillar proteins,primarily the actomyosin complex,and consequently results in shrinkage of the muscle ?ber (Bai-ley,1984).Our data (Table 1)showed that the change in cook loss was signi ?cant (P <0.0001)from 23to 80C because of a reduced water-holding capacity.Similar re-
TABLE 3.Pearson product-moment correlation coef?cients for temperature,soluble proteins,
collagen,peak force,and cook loss
Soluble Variable Temperature proteins Collagen Peak force Cook loss Temperature 1.0000?0.95320.94180.84700.9575Soluble proteins ?0.9532 1.0000?0.9761?0.9609?0.9483Collagen 0.9418?0.9761 1.00000.93070.8833Peak force 0.8470?0.96090.9307 1.00000.8773Cook loss
0.9575
?0.9483
0.8833
0.8773
1.0000
sults were also reported for beef muscle (Laakkonen et al.,1970;Bouton et al.,1975;Bertola et al.,1994).Dawson et al.(1991)reported a moisture loss of 0.8to 2.9%for broiler meat and 2.9to 7.4%for hen meat during aseptic processing at high temperature (120to 145C)and short time (～10s).Zayas and Naewbanij (1986)also found that total losses from beef increased with heating temperature because of changes in water-holding capacity.
Water-holding capacity of muscle tissue has been related to the extent of heat denaturation of myo ?brillar proteins during thermal processing (Larick and Turner,1992).With increasing temperature,the denaturation of myosin and actin caused structural changes and expelled the sarcoplas-mic ?uid from the muscle ?bers,resulting in water losses from meat tissue (Bertola et al.,1994).A linear model of y 2=a 2+c 2x 2*x 3+d 2x 1*x 2*x 3+ε2was obtained with R 2=0.9858and MSE =0.230.In this model,y 2is cook loss;x 1is temperature;x 2is soluble proteins;x 3is collagen;a 2,c 2,and d 2are the estimated coef ?cients;and ε2is the error term (Table 2).
From the analysis of variance,components in models for both texture and cook loss did not include the main effect term of collagen,which might be due to the small content of collagen in tested meat samples.In summary,increasing the meat temperature from 23to 80C reduced soluble proteins,dissociated myo ?brillar proteins,increased colla-gen solubility,increased cook loss,and affected the texture of ground chicken breast patties.A strong linear correlation was obtained between heating temperature and soluble proteins,heating temperature and collagen,heating tem-perature and toughness,and heating temperature and cook loss (Table 3).The results suggest that both muscle and connective tissue changes during heating may in ?uence texture and cook loss from processed poultry meat.
MURPHY AND MARKS 104
ACKNOWLEDGMENTS
This research was partially supported by the USDA NRI Competitive Grants Program,award No.96-35500-3550. The chicken patties were graciously provided by Tyson Foods,Inc.,Springdale,AR.
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一般过去式 时间状语：yesterday just now (刚刚) the day before three days ag0 a week ago in 1880 last month last year 1. I was in the classroom yesterday. I was not in the classroom yesterday. Were you in the classroom yesterday. 2. They went to see the film the day before. Did they go to see the film the day before. They did go to see the film the day before. 3. The man beat his wife yesterday. The man didn’t beat his wife yesterday. 4. I was a high student three years ago. 5. She became a teacher in 2009. 6. They began to study english a week ago 7. My mother brought a book from Canada last year. 8.My parents build a house to me four years ago . 9.He was husband ago. She was a cooker last mouth. My father was in the Xinjiang half a year ago. 10.My grandfather was a famer six years ago. 11.He burned in 1991
●I wonder if it’s because I have been at school for so long that I’ve grown so crazy about going home. ●It is because she wasn’t well that she fell far behind her classmates this semester. ●I can well remember that there was a time when I took it for granted that friends should do everything for me. ●In order to make a difference to society, they spent almost all of their spare time in raising money for the charity. ●It’s no pleasure eating at school any longer because the food is not so tasty as that at home. ●He happened to be hit by a new idea when he was walking along the riverbank. ●I wonder if I can cope with stressful situations in life independently. ●It is because I take things for granted that I make so many mistakes. ●The treasure is so rare that a growing number of people are looking for it. ●He picks on the weak mn in order that we may pay attention to him. ●It’s no pleasure being disturbed whena I settle down to my work. ●I can well remember that when I was a child, I always made mistakes on purpose for fun. ●It’s no pleasure accompany her hanging out on the street on such a rainy day. ●I can well remember that there was a time when I threw my whole self into study in order to live up to my parents’ expectation and enter my dream university. ●I can well remember that she stuck with me all the time and helped me regain my confidence during my tough time five years ago. ●It is because he makes it a priority to study that he always gets good grades. ●I wonder if we should abandon this idea because there is no point in doing so. ●I wonder if it was because I ate ice-cream that I had an upset student this morning. ●It is because she refused to die that she became incredibly successful. ●She is so considerate that many of us turn to her for comfort. ●I can well remember that once I underestimated the power of words and hurt my friend. ●He works extremely hard in order to live up to his expectations. ●I happened to see a butterfly settle on the beautiful flower. ●It’s no pleasure making fun of others. ●It was the first time in the new semester that I had burned the midnight oil to study. ●It’s no pleasure taking everything into account when you long to have the relaxing life. ●I wonder if it was because he abandoned himself to despair that he was killed in a car accident when he was driving. ●Jack is always picking on younger children in order to show off his power. ●It is because he always burns the midnight oil that he oversleeps sometimes. ●I happened to find some pictures to do with my grandfather when I was going through the drawer. ●It was because I didn’t dare look at the failure face to face that I failed again. ●I tell my friend that failure is not scary in order that she can rebound from failure. ●I throw my whole self to study in order to pass the final exam. ●It was the first time that I had made a speech in public and enjoyed the thunder of applause. ●Alice happened to be on the street when a UFO landed right in front of her. ●It was the first time that I had kept myself open and talked sincerely with my parents. ●It was a beautiful sunny day. The weather was so comfortable that I settled myself into the
高中英语~词性~句子成分~语法构成 第一章节：英语句子中的词性 1.名词：n. 名词是指事物的名称，在句子中主要作主语.宾语.表语.同位语。 2.形容词;adj. 形容词是指对名词进行修饰~限定~描述~的成份，主要作定语.表语.。形容词在汉语中是（的）.其标志是: ous. Al .ful .ive。. 3.动词：vt. 动词是指主语发出的一个动作，一般用来作谓语。 4.副词：adv. 副词是指表示动作发生的地点. 时间. 条件. 方式. 原因. 目的. 结果.伴随让步. 一般用来修饰动词. 形容词。副词在汉语中是（地）.其标志是：ly。 5.代词：pron. 代词是指用来代替名词的词，名词所能担任的作用，代词也同样.代词主要用来作主语. 宾语. 表语. 同位语。 6.介词：prep.介词是指表示动词和名次关系的词，例如：in on at of about with for to。其特征：
介词后的动词要用—ing形式。介词加代词时，代词要用宾格。例如：give up her（him）这种形式是正确的，而give up she（he）这种形式是错误的。 7.冠词：冠词是指修饰名词，表名词泛指或特指。冠词有a an the 。 8.叹词：叹词表示一种语气。例如：OH. Ya 等 9.连词：连词是指连接两个并列的成分，这两个并列的成分可以是两个词也可以是两个句子。例如：and but or so 。 10.数词：数词是指表示数量关系词，一般分为基数词和序数词 第二章节：英语句子成分 主语：动作的发出者，一般放在动词前或句首。由名词. 代词. 数词. 不定时. 动名词. 或从句充当。 谓语：指主语发出来的动作，只能由动词充当，一般紧跟在主语后面。 宾语：指动作的承受着，一般由代词. 名词. 数词. 不定时. 动名词. 或从句充当. 介词后面的成分也叫介词宾语。 定语：只对名词起限定修饰的成分，一般由形容
M A: Has the case been closed yet? B: No, the magistrate still needs to decide the outcome. magistrate n.地方行政官，地方法官，治安官 A: I am unable to read the small print in the book. B: It seems you need to magnify it. magnify vt.１．放大，扩大；２．夸大，夸张 A: That was a terrible storm. B: Indeed, but it is too early to determine the magnitude of the damage. magnitude n.１．重要性，重大；２．巨大，广大 A: A young fair maiden like you shouldn’t be single. B: That is because I am a young fair independent maiden. maiden n.少女，年轻姑娘，未婚女子 a.首次的，初次的 A: You look majestic sitting on that high chair. B: Yes, I am pretending to be the king! majestic a.雄伟的，壮丽的，庄严的，高贵的 A: Please cook me dinner now. B: Yes, your majesty, I’m at your service. majesty n.１．［Ｍ－］陛下（对帝王，王后的尊称）；２．雄伟，壮丽，庄严 A: Doctor, I traveled to Africa and I think I caught malaria. B: Did you take any medicine as a precaution? malaria n.疟疾 A: I hate you! B: Why are you so full of malice? malice n.恶意，怨恨 A: I’m afraid that the test results have come back and your lump is malignant. B: That means it’s serious, doesn’t it, doctor? malignant a.１．恶性的，致命的；２．恶意的，恶毒的 A: I’m going shopping in the mall this afternoon, want to join me? B: No, thanks, I have plans already. mall n.（由许多商店组成的）购物中心 A: That child looks very unhealthy. B: Yes, he does not have enough to eat. He is suffering from malnutrition.
意见应以事实为根据. 3 来自辞典例句 192. The bombers swooped ( down ) onthe air base. 轰炸机 突袭 空军基地. 来自辞典例句 193. He mounted their engines on a rubber base. 他把他们的发动机装在一个橡胶垫座上. 14 来自辞典例句 194. The column stands on a narrow base. 柱子竖立在狭窄的地基上. 14 来自辞典例句 195. When one stretched it, it looked like grey flakes on the carvas base. 你要是把它摊直, 看上去就象好一些灰色的粉片落在帆布底子上. 18 来自辞典例句 196. Economic growth and human well - being depend on the natural resource base that supports all living systems. 经济增长和人类的福利依赖于支持所有生命系统的自然资源. 12 1 来自辞典例句 197. The base was just a smudge onthe untouched hundred - mile coast of Manila Bay. 那基地只是马尼拉湾一百英里长安然无恙的海岸线上一个硝烟滚滚的污点. 6 来自辞典例句 198. You can't base an operation on the presumption that miracles are going to happen. 你不能把行动计划建筑在可能出现奇迹的假想基础上.
英语造句大全English sentence 在句子中，更好的记忆单词！ 1、(1)、able adj. 能 句子：We are able to live under the sea in the future. (2)、ability n. 能力 句子：Most school care for children of different abilities. (3)、enable v. 使。。。能句子：This pass enables me to travel half-price on trains. 2、(1)、accurate adj. 精确的句子：We must have the accurate calculation. (2)、accurately adv. 精确地 句子：His calculation is accurately. 3、(1)、act v. 扮演 句子：He act the interesting character. （2）、actor n. 演员 句子：He was a famous actor. (3)、actress n. 女演员 句子：She was a famous actress. (4)、active adj. 积极的 句子：He is an active boy. 4、add v. 加 句子：He adds a little sugar in the milk. 5、advantage n. 优势 句子：His advantage is fight. 6、age 年龄n. 句子：His age is 15. 7、amusing 娱人的adj. 句子：This story is amusing. 8、angry 生气的adj. 句子：He is angry. 9、America 美国n.
主语+谓语 1. 理解主谓结构 1) The students arrived. The students arrived at the park. 2) They are listening. They are listening to the music. 3) The disaster happened. 2．体会状语的位置 1) Tom always works hard. 2) Sometimes I go to the park at weekends.. 3) The girl cries very often. 4) We seldom come here. The disaster happened to the poor family. 3. 多个状语的排列次序 1) He works. 2) He works hard. 3) He always works hard. 4) He always works hard in the company. 5) He always works hard in the company recently. 6) He always works hard in the company recently because he wants to get promoted. 4. 写作常用不及物动词 1. ache My head aches. I’m aching all over. 2. agree agree with sb. about sth. agree to do sth. 3. apologize to sb. for sth. 4. appear (at the meeting, on the screen) 5. arrive at / in 6. belong to 7. chat with sb. about sth. 8. come (to …) 9. cry 10. dance 11. depend on /upon 12. die 13. fall 14. go to … 15. graduate from 16. … happen 17. laugh 18. listen to... 19. live 20. rise 21. sit 22. smile 23. swim 24. stay (at home / in a hotel) 25. work 26. wait for 汉译英： 1.昨天我去了电影院。 2.我能用英语跟外国人自由交谈。 3.晚上7点我们到达了机场。 4.暑假就要到了。 5.现在很多老人独自居住。 6.老师同意了。 7.刚才发生了一场车祸。 8.课上我们应该认真听讲。9. 我们的态度很重要。 10. 能否成功取决于你的态度。 11. 能取得多大进步取决于你付出多少努力。 12. 这个木桶能盛多少水取决于最短的一块板子的长度。
【it's time to和it's time for】 ——————这其实是一个句型,只不过后面要跟不同的东西. ——————It's time to跟的是不定式（to do）.也就是说,要跟一个动词,意思是“到做某事的时候了”.如： It's time to go home. It's time to tell him the truth. ——————It's time for 跟的是名词.也就是说,不能跟动词.如： It's time for lunch.(没必要说It's time to have lunch) It's time for class.(没必要说It's time to begin the class.) They can't wait to see you Please ask liming to study tonight. Please ask liming not to play computer games tonight. Don’t make/let me to smoke I can hear/see you dance at the stage You had better go to bed early. You had better not watch tv It’s better to go to bed early It’s best to run in the morning I am enjoy running with music. With 表伴随听音乐 I already finish studying You should keep working. You should keep on studying English Keep calm and carry on 保持冷静继续前行二战开始前英国皇家政府制造的海报名字 I have to go on studying I feel like I am flying I have to stop playing computer games and stop to go home now I forget/remember to finish my homework. I forget/remember cleaning the classroom We keep/percent/stop him from eating more chips I prefer orange to apple I prefer to walk rather than run I used to sing when I was young What’s wrong with you There have nothing to do with you I am so busy studying You are too young to na?ve I am so tired that I have to go to bed early
《The Kite Runner》追风筝的人--------------------------------美句摘抄 1.I can still see Hassan up on that tree, sunlight flickering through the leaves on his almost perfectly round face, a face like a Chinese doll chiseled from hardwood: his flat, broad nose and slanting, narrow eyes like bamboo leaves, eyes that looked, depending on the light, gold, green even sapphire 翻译：我依然能记得哈桑坐在树上的样子，阳光穿过叶子，照着他那浑圆的脸庞。他的脸很像木头刻成的中国娃娃，鼻子大而扁平，双眼眯斜如同竹叶，在不同光线下会显现出金色、绿色，甚至是宝石蓝。 E.g.: A shadow of disquiet flickering over his face. 2.Never told that the mirror, like shooting walnuts at the neighbor's dog, was always my idea. 翻译：从来不提镜子、用胡桃射狗其实都是我的鬼主意。E.g.:His secret died with him, for he never told anyone. 3.We would sit across from each other on a pair of high
一、翻译 1. The idea of consciously seeking out a special title was new to me., but not without appeal. 让我自己挑选自己最喜欢的书籍这个有意思的想法真的对我具有吸引力。 2.I was plunged into the aching tragedy of the Holocaust, the extraordinary clash of good, represented by the one decent man, and evil. 我陷入到大屠杀悲剧的痛苦之中，一个体面的人所代表的善与恶的猛烈冲击之中。 3.I was astonished by the the great power a novel could contain. I lacked the vocabulary to translate my feelings into words. 我被这部小说所包含的巨大能量感到震惊。我无法用语言来表达我的感情（心情）。 4，make sth. long to short长话短说 5.I learned that summer that reading was not the innocent(简单的) pastime(消遣) I have assumed it to be., not a breezy, instantly forgettable escape in the hammock(吊床)，( though I’ ve enjoyed many of those too ). I discovered that a book, if it arrives at the right moment, in the proper season, will change the course of all that follows. 那年夏天，我懂得了读书不是我认为的简单的娱乐消遣，也不只是躺在吊床上，一阵风吹过就忘记的消遣。我发现如果在适宜的时间、合适的季节读一本书的话，他将能改变一个人以后的人生道路。 二、词组造句 1. on purpose 特意，故意 This is especially true here, and it was ~. (这一点在这里尤其准确，并且他是故意的) 2.think up 虚构，编造，想出 She has thought up a good idea. 她想出了一个好的主意。 His story was thought up. 他的故事是编出来的。 3. in the meantime 与此同时 助记：in advance 事前in the meantime 与此同时in place 适当地... In the meantime, what can you do? 在这期间您能做什么呢？ In the meantime, we may not know how it works, but we know that it works. 在此期间，我们不知道它是如何工作的，但我们知道，它的确在发挥作用。 4.as though 好像，仿佛 It sounds as though you enjoyed Great wall. 这听起来好像你喜欢长城。 5. plunge into 使陷入 He plunged the room into darkness by switching off the light. 他把灯一关，房
The effective sentences:(improve the sentences!) 1.She hopes to spend this holiday either in Shanghai or in Suzhou. 2.Showing/to show sincerity and to keep/keeping promises are the basic requirements of a real friend. 3.I want to know the space of this house and when it was built. I want to know how big this house is and when it was built. I want to know the space of this house and the building time of the house. 4.In the past ten years,Mr.Smith has been a waiter,a tour guide,and taught English. In the past ten years,Mr.Smith has been a waiter,a tour guide,and an English teacher. 5.They are sweeping the floor wearing masks. They are sweeping the floor by wearing masks. wearing masks,They are sweeping the floor. 6.the drivers are told to drive carefully on the radio. the drivers are told on the radio to drive carefully 7.I almost spent two hours on this exercises. I spent almost two hours on this exercises. 8.Checking carefully,a serious mistake was found in the design. Checking carefully,I found a serious mistake in the design.
M1 U1 一. 把下列短语填入每个句子的空白处（注意所填短语的形式变化）： add up (to) be concerned about go through set down a series of on purpose in order to according to get along with fall in love (with) join in have got to hide away face to face 1 We’ve chatted online for some time but we have never met ___________. 2 It is nearly 11 o’clock yet he is not back. His mother ____________ him. 3 The Lius ___________ hard times before liberation. 4 ____________ get a good mark I worked very hard before the exam. 5 I think the window was broken ___________ by someone. 6 You should ___________ the language points on the blackboard. They are useful. 7 They met at Tom’s party and later on ____________ with each other. 8 You can find ____________ English reading materials in the school library. 9 I am easy to be with and _____________my classmates pretty well. 10 They __________ in a small village so that they might not be found. 11 Which of the following statements is not right ____________ the above passage? 12 It’s getting dark. I ___________ be off now. 13 More than 1,000 workers ___________ the general strike last week. 14 All her earnings _____________ about 3,000 yuan per month. 二.用以下短语造句： 1.go through 2. no longer/ not… any longer 3. on purpose 4. calm… down 5. happen to 6. set down 7. wonder if 三. 翻译： 1.曾经有段时间，我对学习丧失了兴趣。（there was a time when…） 2. 这是我第一次和她交流。（It is/was the first time that …注意时态） 3.他昨天公园里遇到的是他的一个老朋友。（强调句） 4. 他是在知道真相之后才意识到错怪女儿了。（强调句） M 1 U 2 一. 把下列短语填入每个句子的空白处（注意所填短语的形式变化）： play a …role (in) because of come up such as even if play a …part (in) 1 Dujiangyan(都江堰) is still ___________in irrigation(灌溉) today. 2 That question ___________ at yesterday’s meeting. 3 Karl Marx could speak a few foreign languages, _________Russian and English. 4 You must ask for leave first __________ you have something very important. 5 The media _________ major ________ in influencing people’s opinion s. 6 _________ years of hard work she looked like a woman in her fifties. 二.用以下短语造句： 1.make (good/full) use of 2. play a(n) important role in 3. even if 4. believe it or not 5. such as 6. because of
English sentence 1、(1)、able adj. 能 句子：We are able to live under the sea in the future. (2)、ability n. 能力 句子：Most school care for children of different abilities. (3)、enable v. 使。。。能 句子：This pass enables me to travel half-price on trains. 2、(1)、accurate adj. 精确的 句子：We must have the accurate calculation. (2)、accurately adv. 精确地 句子：His calculation is accurately. 3、(1)、act v. 扮演 句子：He act the interesting character.（2）、actor n. 演员 句子：He was a famous actor. (3)、actress n. 女演员 句子：She was a famous actress. (4)、active adj. 积极的 句子：He is an active boy. 4、add v. 加 句子：He adds a little sugar in the milk. 5、advantage n. 优势 句子：His advantage is fight. 6、age 年龄n. 句子：His age is 15. 7、amusing 娱人的adj. 句子：This story is amusing. 8、angry 生气的adj. 句子：He is angry. 9、America 美国n. 句子：He is in America. 10、appear 出现v. He appears in this place. 11. artist 艺术家n. He is an artist. 12. attract 吸引 He attracts the dog. 13. Australia 澳大利亚 He is in Australia. 14.base 基地 She is in the base now. 15.basket 篮子 His basket is nice. 16.beautiful 美丽的 She is very beautiful. 17.begin 开始 He begins writing. 18.black 黑色的 He is black. 19.bright 明亮的 His eyes are bright. 20.good 好的 He is good at basketball. 21.British 英国人 He is British. 22.building 建造物 The building is highest in this city 23.busy 忙的 He is busy now. 24.calculate 计算 He calculates this test well. 25.Canada 加拿大 He borns in Canada. 26.care 照顾 He cared she yesterday. 27.certain 无疑的 They are certain to succeed. 28.change 改变 He changes the system. 29.chemical 化学药品