【作者】 黄俊程；

【导师】 马立保；

【作者基本信息】 华中农业大学 ， 动物营养与饲料科学， 2011， 硕士

【摘要】 为了研究热处理程度对棉粕消化能值、蛋白质及回肠末端氨基酸消化率的影响,本研究采集相同品种棉仁,通过实验室模拟生产工艺中蒸炒环节,设定温度在116℃,调整不同加热时间,得到不同受热程度的棉粕,研究热处理程度对棉粕蛋白质溶解度(PS)、化学成分、氨基酸消化率的影响。试验一：热处理程度对棉粕PS、化学成分的影响研究冷榨所得棉粕,经高压灭菌锅湿热处理,温度固定在116℃,设置热处理时间分别为：Omin,10min,15min,20min,30min,40min,45min,55min,60min, 65min,75min.并从中选取5种PS差异显著(P<0.05)的棉粕进一步测定粗蛋白质、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、游离棉酚(FG)等化学指标。本试验结果表明：(1)随着热处理时间延长,棉粕颜色发生改变,PS显著下降。PS与热处理程度显著相关,且符合一元二次方程：PS=88.17-0.94T+0.0046T2 (R2=0.9861,P<0.001；T表示时间)。(2)随着热处理时间的延长,棉粕中NDF.ADF含量均显著升高(P<0.05)。FG含量显著下降(P<0.05)。热处理程度与NDF的关系符合一元一次方程：Y(NDF)=15.53+0.37T (R2=0.9732；P<0.001)；热处理程度与FG的关系符合一元二次方程Y(FG)= 1295.74-31.95T+0.29T2(R2=0.9560;P<0.009).试验二：热处理程度对棉粕消化能值(DE)蛋白质及氨基酸消化率的影响用酪蛋白、玉米淀粉配置成半纯合日粮,再分别与五种PS为：69%、61%、55%、49%、42%的棉粕配制成试验日粮。选用6头长大二元杂交阉公猪,体重为(45±2)kg,通过6×6拉丁方设计,消化试验测定热处理程度对棉粕的消化能值的影响。试验结果表明：(1)五种PS分别为：69%、61%、55%、49%、42%的棉粕消化能值分别为：11.9MJ/Kg.13.1MJ/Kg.12.5MJ/kg.12.3MJ/Kg.11.1MJ/Kg.棉粕消化能值与热处理时间及PS有显著的相关关系,在PS为61%时消化能值最高。(2)PS与消化能值的相关关系符合2次曲线,其预测模型为：DE(MJ/Kg) =13.079+0.911PS-0.079PS2(R2=0.9328,P<0.05).棉粕消化能值与NDF含量有显著的相关关系。其预测模型为：DE(MJ8Kg)=0.3143NDF2+1.6457NDF+10.7 (R2=0.8872,P<0.05)(3)随着热处理时间的延长,PS逐渐降低,回肠末端蛋白质消化率及粪中蛋白质消化率均呈现先升高后降低的规律。但回肠末端蛋白质消化率低于粪中蛋白质消化率。(4)不论是回肠末端还是粪中蛋白质消化率PS为55%的棉粕均最高。(5)随着热处理时间的延长,棉粕PS的降低,天冬氨酸、苏氨酸、色氨酸、等氨基酸表观及真消化率均呈现先升高后降低的趋势,其中苏氨酸在热处理时间为30min,PS为61%时表观及真消化率均最高。赖氨酸、精氨酸、苯丙氨酸、酪氨酸等氨基酸表观及真消化率均显著下降。以在热处理时间为20min,PS为69%时表观及真消化率均最高。试验四：热处理程度对棉粕蛋白质体外消化率的影响通过2步酶解法,选用胃蛋白酶、胰蛋白酶,模拟动物体胃肠道环境,测定热处理程度对棉粕蛋白质体外消化率的影响。试验结果表明：随着热处理时间的延长,PS下降,蛋白质体外消化率显著下降。在热处理时间为20min,溶解度为69%时其蛋白质体外消化率最高。棉粕体外蛋白质消化率与蛋白质溶解度显著相关。且符合一元一次方程：Y(CP体外消化率)=0.4353+0.2914PS(R2=0.989;P<0.05)。更多还原

【Abstract】 The cotton seeds of the same kind vary in colors and physico-chemical properties such as the PS due to different technological skills during the actual production process in each refinery, such as different heating temperature and time in the hot working. To study the effects of heat treatment on the DE, protein and ileal digestibility value of amino acids in cotton seeds, this research collects the cotton seeds of the same kind but with different PS in Hubei province. The effects of different process time on the PS and chemical ingredients can be observed by simulating the heat treatment in the production process with the temperature set at 116℃while changing the heat-up time; the relationship between DE and PS can be determined by testing the digestibility of 6 chosen pigs by means of square design; another 6 pigs are chosen so that the relationship between ileal digestibility value of amino acids and the heating time can be determined by testing the proteins of cotton seeds, digestibility value of amino acids and protein digestibility value in feces by means of T-fistula method and square design so as to simplify the testing methods and offer guidance to the actual application of cotton seeds and the making of the diet.Test One:The effects of heating on PS and chemical composition of cottonseed meal.The effects of the heating time on the PS can be observed through the heat treatment of cold-pressed cotton seeds in the autoclaves with the temperature set at 116℃while changing the heating time to Omin, 10min,15min,20min,30min,40min,45min, 55min,60min,65min and 75min. Then 5 kinds of cotton seeds with strikingly different PS are chosen to further test all the chemical ingredients and study the effect of heating time on them.The test shows:i. The colors of cotton seeds change and the PS declines markedly as the heating time prolongs. The PS is strikingly reverent to the heating time and their relation accords with unary quadratic curves:PS=88.17-0.94T+0.0046T2 (R2=0.9861, P<0.001; T is short for time).ii. The NDF and ADF content increase strikingly while FG content declines markedly.The relation between time and NDF accords with equation of a degree:Y(NDF)= 15.53+0.37T (R2=0.9732; P<0.001); the relation between time and FG accords with equation of two degree:Y(FG)=1295.74-31.95T+0.29T2(R2=0.9560;P<0.009).Test Two:The effects of heating on cottonseed meal digestible energy values and the ileal amino acid digestibility of pig researchthe relationship between DE and PS can be determined by testing the digestibility of 6 chosen pigs by means of square design; another 6 pigs are chosen so that the relationship between ileal digestibility value of amino acids and the heating time can be determined by testing the proteins of cotton seeds.The teat shows:i Five PS were:69%,61%,55%,49%,42%of the cottonseed meal digestible energy values were:11.9MJ/Kg,13.1MJ/Kg,12.5MJ/Kg,12.3MJ/Kg,11.1 MJ /Kg.The DE value is markedly related to the heating time and PS. The cotton seeds have the highest DE values when the heating time is 30min and the PS is 61%.ii The relation between PS and DE value accords with quadratic equation. The prediction model established by their relation:DE(MJ/Kg)=13.079+0.911PS-0.079PS2(R2=0.9328, P<0.05). The DE value is strikingly related to NDF content and their relation accords with quadratic equation. The prediction model: DE(MJ/Kg)=-0.3143NDF2+1.6457NDF+10.7(R2=0.8872, P<0.05).iii The PS gradually reduces and terminal ileum protein digestibility value and protein digestibility value in feces rise first and then drop.The terminal ileum protein digestibility value is lower than the protein digestibility value in the body of animals.The cotton seeds whose PS values are 55% have the highest digestibility values in the terminal ileums and the feces.iv. The digestibility values of aspartic, threonine, serine and lysine rise first and then drop as the heating time prolongs and the PS values decrease. The lysine has the highest digestibility value when the PS value is 61% and the heating time is 30min. Arginine, phenylalanine and tyrosine markedly decrease and has the highest digestibility value when the PS value is 69% and the heating time is 20min.Test Four:The protein digestibility value of cotton seeds in vitro methodThe test shows that the protein digestibility value strikingly drops as the heating time prolongs and the PS decreases. The vitro digestibility value is the highest when the heating time is 20min and the PS is 69%.更多还原