生物与物理复合法脱除棉籽粕中游离棉酚的工艺研究

本试验旨在研究微生物固态发酵与微波降解分步复合法脱除棉籽粕中游离棉酚的加工技术。以棉籽浸出制油后的棉籽粕为原料,通过不同的菌种、接种量、料液比、发酵温度、发酵时间等影响因素进行试验分析,以棉籽粕的脱毒率为评判标准。首先通过确定正交试验的因素与水平,得出微生物固态发酵的最佳脱毒工艺参数;再以发酵后的湿棉籽粕为原料,采用微波降解工艺进行第二次物理辅助脱毒,确定最佳微波工艺参数;测定脱毒前后的棉籽粕粗蛋白含量和小肽含量。结果表明:混菌发酵比2∶1(枯草芽孢杆菌与酵母菌)、接种量10%、料液比2∶3、发酵时间48 h、发酵温度30℃,脱毒效果最佳,此时脱毒率高达86.57%;当微波时间和功率分别为6 min和3 000 W时,最终棉籽粕脱毒可达90.57%。测定脱毒后的棉籽粕粗蛋白含量为52.17%,提高了25.29%;小肽含量为11.13%,提高了20.19%。所得产品色泽均一,呈黑褐色,无酸臭味。微波过程可脱出一部分水分,有效节约了棉籽粕的烘干成本和烘干时间。此方法工艺简单、安全可靠、流程短、脱毒率高、水耗和能耗低,为棉籽粕的合理开发和利用提供理论基础和试验数据。     

产朊假丝酵母菌发酵降解棉酚的效果

棉粕经高温高压处理后,利用产阮假丝酵母对棉粕进行固体发酵脱毒,通过对生物量的测定,获得最适发酵脱毒条件,然后进行发酵降解棉酚实验,通过测定发酵终点和起始点棉酚的含量,获得产朊假丝酵母对棉酚的降解率。结果显示最适发酵条件为:发酵底物含水量为37%,发酵时间48h,发酵温度30℃,接种量为5%。对发酵前和发酵48h后的样品按照国家标准测定方法进行棉酚含量的测定,结果显示棉粕在发酵前后,棉酚去除率在85.7%左右。     

棉籽粕脱酚酵母菌菌株的筛选

本实验通过固态发酵实验,比较了灭菌条件和不灭菌条件下不同酵母菌的脱酚率,最后从4株酵母菌中筛选出1株对棉粕中游离棉酚具有较好降解作用的热带假丝酵母。     

棉籽粕化学脱除棉酚的试验研究

本试验旨在探讨棉籽粕化学脱毒的最佳方法。试验1,通过研究不同水分、温度和作用时间对棉酚脱毒率的影响,确定棉籽粕的脱毒作用最佳水热条件。结果发现,在60~100℃、水分8%~16%和时间20 min~8 h条件范围内,随着温度、水分添加量、作用时间增加,棉籽粕脱毒率越高。试验2,比较10种常见单一化学脱毒剂的脱毒效果。研究发现,硫酸亚铁(Fe SO_4)、硫酸铜(Cu SO_4)和双氧水(H_2O_2)脱毒效果较佳,脱毒率均达到40%以上,然而,Fe SO_4脱毒棉籽粕颜色发黑并带有铁锈味,故Cu SO_4和H_2O_2为较优的单一棉酚脱毒剂。试验3,将Cu SO_4和H_2O_2制成混合脱毒剂,研究其最佳反应条件,并验证其脱毒效果。结果发现,80℃、16%脱毒剂添加量和烘1 h为最佳脱毒条件,且此混合脱毒剂的游离棉酚和结合棉酚的脱毒率均在84%以上;虽然脱毒后脱毒棉籽粕粗蛋白质含量稍微降低(P0.05),但粗蛋白质消化率显著提高(P0.05)。因此,水分、温度、作用时间都是影响棉籽粕化学脱毒的重要因素,在控制好这3个条件的情况下(80℃、16%脱毒剂添加量和密闭烘1 h时间),选用H_2O_2、Cu SO_4配制成一种混合脱毒剂,能有效脱除棉籽粕棉酚并且提高棉籽粕粗蛋白质消化率和仿生消化能,为棉籽粕脱毒加工提供良好的理论和技术支持。     

氯化胆碱和乙醇胺对假丝酵母发酵棉籽饼脱毒、产酶和生物量的影响

通过测定棉籽饼发酵底物游离棉酚含量、蛋白酶活性和生物量的方法研究氯化胆碱和乙醇胺对棉籽饼发酵效果的影响。试验结果表明,发酵热处理底物时,氯化胆碱、乙醇胺均不能促进发酵脱毒,但可极显著提高底物中性蛋白酶、酸性蛋白酶活性以及底物生物量,其中氯化胆碱效果较好。发酵非热处理底物时,乙醇胺显著降低发酵脱毒效率、底物生物量,氯化胆碱有促进发酵脱毒的趋势、极显著提高底物生物量;两处理因素均可极显著提高底物碱性蛋白酶活性,降低酸性蛋白酶活性。氯化胆碱对棉籽饼底物发酵脱毒和底物营养价值有重要的意义。     

高效降解棉粕中游离棉酚菌种的筛选

试验从保藏的10株不同微生物菌种中筛选出2株能有效降解棉粕中游离棉酚的菌株Y-4和B-2。通过在实验室灭菌条件下的固态发酵试验,确定了各个菌株的脱酚率,其中菌株Y-4和B-2脱酚率较高分别为41.4%和35%。为了实现工业化大生产,进行了不灭菌条件下的固态发酵试验,结果表明各个菌均对棉粕中的游离棉酚具有一定的降解作用,其中Y-4和B-2的脱酚率最高分别可达47.5%和38.2%。     

高效液相色谱测定棉酚方法的建立及不同棉酚脱毒方法比较

棉籽粕是一种非常有价值的蛋白质饲料,棉籽粕的有效脱毒可以提高饲料利用率。本试验建立了一种快速、准确测定棉籽粕游离棉酚的HPLC方法,并采用不同的脱毒方式对棉籽粕中的游离棉酚进行降解,筛选最优脱毒方法。结果显示:(1)HPLC法测定棉籽粕中棉酚含量,棉酚色谱峰出峰稳定性良好、分离效果好、峰型理想、灵敏度高,可以高效的检测棉酚含量;(2)不同处理方法对棉籽粕脱毒效果不同,棉酚脱毒率大小排序为:微生物法>硫酸亚铁法>尿素法>高温高压法。最优的方法为微生物法,酵母菌发酵48 h后的发酵棉籽粕棉酚降解率高达93.86%;化学法(硫酸亚铁法和尿素法)脱毒率为53.64%～78.18%,物理法(高温高压)脱毒率最低,为41.00%。     

固态生料发酵棉籽粕菌种筛选及发酵工艺的研究

本研究旨在考察不同菌种组合和不同工艺参数对棉籽粕固态生料发酵后游离棉酚、营养成分和有益代谢产物的影响,以优化出最佳菌种组合和发酵工艺,并获得游离棉酚显著降低、营养价值显著提升的发酵棉籽粕。棉籽粕分别通过单菌发酵、混菌同步发酵和混菌分步发酵,依据发酵后的感官评定、活菌数和pH变化以及发酵棉籽粕的游离棉酚、酸溶蛋白、粗蛋白质和L-乳酸含量为筛选指标,筛选出发酵菌种的最佳组合;通过正交试验确定棉籽粕发酵的最佳工艺条件。结果表明：1）混菌分步发酵效果优于单菌发酵和混菌同步发酵,最佳菌种组合和发酵方式为先接种酿酒酵母（Saccharomyces cerevisiae）SC17-1和植物乳杆菌（Labacillus planetarum）LP15-1进行厌氧发酵,再接种枯草芽孢杆菌（Bacillus subtils） BS15-3进行好氧发酵。2）正交试验确定的最佳发酵工艺为料水比1.00∶0.80,接种酿酒酵母SC17-1和植物乳杆菌LP15-1厌氧发酵2 d,然后接种枯草芽孢杆菌BS15-3好氧发酵2 d,发酵温度均为30℃,接种比例为酿酒酵母SC17-1∶植物乳杆菌LP15-1∶枯草芽孢杆菌...     

蒸汽爆破技术对棉籽粕中游离棉酚脱毒效果研究

本试验旨在研究蒸汽爆破技术对棉籽粕中游离棉酚的脱毒效果。采用市售棉籽粕,对其进行7种不同的蒸汽爆破处理,蒸汽压强均固定为2.0 MPa,以水料比为0时进行维压30 s的蒸汽爆破处理为对照,水料比为30%、50%时分别进行维压10、20、30 s的爆破处理,每处理重复3次,以游离棉酚含量、蛋白质溶解度为指标,筛选出较佳的处理测定氨基酸含量和营养物质猪仿生消化率数据。结果表明:固定蒸汽压强时,游离棉酚的脱毒率与蛋白质溶解度随着蒸汽维压时间延长而增加,随着水料比的增加先增大后减少。以游离棉酚的脱毒效果与蛋白质溶解度为指标,筛选出的适宜蒸汽爆破处理为蒸汽压强2.0 MPa,水料比30%,维压时间30 s。此时棉籽粕中游离棉酚含量达85.0 mg/kg,脱毒率达87.0%,蛋白质溶解度为42.3%。与对照组相比,蒸汽爆破可极显著降低棉籽粕中赖氨酸含量和精氨酸含量(P0.01),对体外干物质消化率和总能消化率无显著影响(P0.05),极显著降低体外粗蛋白质消化率和赖氨酸消化率(P0.01)。由此可见,蒸汽爆破处理可降低棉籽粕游离棉酚含量、蛋白质溶解度、赖氨酸含量、精氨酸含量、体外粗蛋白质消化率和赖氨酸消化率。筛选出的适宜蒸汽爆破处理为蒸汽压强2.0 MPa,水料比30%,维压时间30 s。     

棉籽粕中游离棉酚测定的影响因素及方法研究

本试验考察了影响棉籽粕中游离棉酚检测结果的主要因素以及检测方法．包括检测游离棉酚时做空白对照时苯胺试剂的影响：检测游离棉酚时原料粉碎与否的影响：检测过程中浸提方式的选择。结果表明：对照组中苯胺若被氧化后测出的空白值偏高：原料被粉粹后．检测结果偏高：自然浸提12h检测游离棉酚和国标中振荡1h浸提游离棉酚检测结果一致．     

棉籽饼粕脱毒的研究进展

棉籽饼粕是一种重要的蛋白质资源，但含有一定量棉酚，限制棉籽饼粕利用。研究适宜的方法脱除或钝化游离棉酚，对开发优质蛋白资源具有重大意义。本文综述了棉籽饼粕的有毒物质，目前的脱毒研究及其存在的问题。     

Effects of gossypol from cottonseed meal and dietary vitamin E on the reproductive characteristics of superovulated beef heifers

Superovulated Hereford-Angus crossbred heifers (average 397 kg BW) were used to test the effect of feeding cottonseed meal (gossypol) and vitamin E on embryo quality and ovarian characteristics. Twenty-four heifers were assigned randomly to four treatments with six heifers per treatment. Treatments were the following dietary supplements: 1) SBM (soybean meal + 30 IU vitamin E/kg of diet DM); 2) SBM+E (soybean meal + 4,000 IU vitamin E x animal(-1) x d(-1)); 3) CSM (cottonseed meal + 30 IU vitamin E/kg of diet DM); and 4) CSM+E (cottonseed meal + 4,000 IU vitamin E x animal(-1) x d(-1)). Supplements based on cottonseed meal provided 43.5 g of total gossypol/d (37% negative isomer (-) and 63% positive isomer (+)). Blood samples were collected at the start of the experiment and every 3 wk thereafter up to 12 wk. Plasma a-tocopherol (alpha-T) concentration was affected by treatments (P < 0.05). Heifers supplemented with cottonseed meal had greater (P < 0.05) alpha-T concentration in plasma than heifers supplemented with soybean meal at each concentration of vitamin E. Supplementation at 4,000 IU vitamin E x animal(-1) d(-1) increased (P < 0.05) the concentration of a-T in plasma. Weight gain, hemoglobin and hematocrit were not affected by treatment. Erythrocyte osmotic fragility (EOF) increased (P < 0.05) in cottonseed meal-fed animals; however, EOF was lowered (P < 0.05) with vitamin E supplementation. Heifers fed CSM and CSM+E supplements had greater (P < 0.01) concentrations of (-)-, (+)-, and total-gossypol in plasma, corpora lutea (CL), liver, and endometrium than heifers fed SBM and SBM+E supplements. Tissue alpha-T concentration increased with increased dietary supplemental vitamin E, particularly in great amounts in the CL. Because there was no adverse effect of gossypol on superovulation response or embryo development despite concentrations of gossypol in endometrium that are toxic to embryos, it is likely that systems exist in the reproductive tract to limit gossypol toxicity.     

生料固态发酵法降解棉酚的工艺研究

以黑曲霉WL-85为发酵菌种,对应用生料发酵技术降解棉酚以及发酵工艺条件进行了研究,在单因素试验的基础上进行了正交试验,结果表明:生料发酵技术也可以有效降解棉酚,在温度27℃、发酵时间24 h、pH 5的条件下进行固态好氧发酵,脱毒率达到65.07%。     

Effects of dietary cottonseed meal and iron-treated cottonseed meal in different laying hen genotypes

The effects of dietary screw-pressed cottonseed meal (CSM) and iron-treated CSM on laying performance and discolourations in eggs were examined in a range of hen genotypes. In experiment 1, six genotypes, obtained at point-of-lay from various sources, were fed on a non-CSM diet, a diet with 300 g CSM/kg, and a diet containing iron-treated CSM at 300 g/kg. In experiment 2, two of these genotypes were reared together from day-old and were fed from 10 to 18 weeks on a non-CSM diet or a diet containing iron-treated CSM at 250 g/kg. They were then fed on a non-CSM layer diet or a diet containing iron-treated CSM at 300 g/kg, in a 2 x 2 x 2 factorial design that also examined the effects of the rearing diet. 2. The effects on food intakes and egg production of including CSM and iron-treated CSM in layer diets depended on the genotype of the hens. The strongest interaction between breed and diet was on food intake, the breed Hubbard Golden Comet (HGC) being the least tolerant of CSM and iron-treated CSM. 3. Inclusion of iron-treated CSM in the rearer diet to supply approximately 70% of the dietary protein had no adverse effects on growth or age at first egg. Food intake and egg production between 18 and 26 weeks were affected by the iron-treated CSM layer diet, but there were no carry-over effects attributable to the rearing diets. 4. Genotype was not a factor in the development of the gossypol-related brown yolk discolouration in fresh or warm-stored eggs of hens fed on a CSM-based diet containing 197 mg free gossypol/kg and 52 mg cyclopropenoid fatty acids (CPFA)/kg (experiment 1). 5. In both experiments, the susceptibility of eggs to the CPFA-related cold storage effects depended on the genotype of the hen, eggs from hens of the HCG breed being more affected than those of ISA hens. 6. Treatment of CSM with crystalline ferrous sulphate heptahydrate, at a 4:1 weight ratio of iron to free gossypol, prevented brown yolk discolourations in all genotypes tested, as assessed by subjecting egg yolks to atmospheres of ammonia, and cold storage of eggs.     

棉粕和棉籽壳诱发雄性细毛羊尿结石

用棉粕和棉籽壳诱发雄性细毛羊尿结石,研究棉粕和棉籽壳引起雄性细毛羊尿结石的致病因素.测定结石羊血清和尿液的生化指标,观察尿液结晶和泌尿系统组织形态变化,并应用X线能谱分析法、X线衍射分析法、扫描电子显微镜观察法和红外分析光谱法对结石进行微观结构观察和成分分析.结果显示,膀胱结石主要成分为MgKPO4和MgKPO4·6H2O,肾结石主要成分为Mg2P2O7.结果表明,在产棉区,绵羊尿结石是由棉粕和棉籽壳导致的矿物质营养代谢疾病,尿结石的发生与棉粕和棉籽壳中高剂量棉酚和磷、钾、镬代谢有密切关系.     

Effects of gossypol and cottonseed products on reproduction of mammals.

Gossypol is a toxic factor indigenous to the cotton plant genus Gossypium. Concentrations of free gossypol contained in feedstuffs such as whole cottonseed and cottonseed meals vary considerably. Nonruminant animals are particularly sensitive to the toxic effects of gossypol, whereas ruminants are somewhat more resistant. Signs of gossypol toxicosis in nonruminants, preruminants, and ruminants are similar and include labored breathing, dyspnea, decreased growth rate, and anorexia but are not pathognomonic. Postmortem findings include generalized edema and congestion of lungs and liver, fluid-filled thoracic and peritoneal cavities, and degeneration of heart fibers. The antifertility effect observed in many nonruminant species is overshadowed by toxic effects, particularly in females. Gossypol seems to disrupt estrous cycles, pregnancy, and early embryo development in females of all nonruminant species studied. Probable mechanisms include an endocrine effect on the ovary as well as a cytotoxic effect on the uterus or embryo. The female ruminant seems to be relatively insensitive to the antifertility effect of gossypol; however, in vitro data indicate some inhibition of embryonic development and ovarian steroidogenesis. The antifertility effect of gossypol has been studied most in males of nonruminant species. The effects of gossypol in the male are both dose- and time-dependent. At effective doses, gossypol causes males to be infertile because of sperm immotility and depressed sperm counts. Specific mitochondrial damage in the tails of spermatozoa seems to render them immotile, and extensive damage to germinal epithelium may be responsible for depressions in spermatogenesis. In ruminant males fed diets containing gossypol, ejaculated sperm appears normal under light microscopy. The integrity of the membrane of sperm cells may be damaged. Extensive damage to the germinal epithelium has been shown in both rams and bulls fed diets containing gossypol and is of major concern.     

复合菌固态发酵棉籽粕工艺的初步研究

文章以枯草芽孢杆菌属、酵母菌属和乳酸菌属的6株菌为出发菌株,通过单因素试验和正交试验,确定了6株菌复合培养的最佳培养基配方为:糖蜜40 g/l、蛋白胨10 g/l、葡萄糖1 g/l、磷酸氢二钾0.5 g/l;并对复合菌固态发酵棉籽粕工艺条件进行了研究,确定了复合菌固态发酵棉籽粕的最适工艺条件为:料水比1:0.8,接种量为3%,发酵温度为30℃p,H值自然,发酵时间为48 h。在以上条件下,棉籽粕经过复合菌固态发酵后,物料的pH值降低到4.5以下,有益菌总数达到6.2×108 cfu/g,粗蛋白含量提高了1.76%,游离棉酚含量从618.52 mg/kg降低到274.16 mg/kg,降低了55.7%。