Effects of a molasses-coated cottonseed product on diet digestibility, performance, and milk fatty acid profile of lactating dairy cattle

An experiment was conducted to evaluate the effects of a molasses-coated cottonseed product on nutrient digestibility and milk fatty acid (FA) composition of lactating dairy cattle. The effect of a direct-fed microbial (DFM) product was also examined. Twelve Holstein cows (693 ± 85 kg of body weight, 127 ± 39 d in milk, 2.08 ± 0.29 lactations; mean ± SD) were randomly assigned to sequence in a replicated 4 × 4 Latin square design balanced for carryover effects. Cows were fed 1 of 4 treatments during each of the four 14-d periods: a control diet including 11.4% (dry matter basis) reginned cottonseed (CON), a diet with 14.4% molasses-coated cottonseed to match the cottonseed inclusion rate of the control diet (TC), the control diet with the addition of a liquid form of the cotton coating used to produce molasses-coated cottonseed (LC), and the LC diet with the addition of a DFM (LC+DFM). Diets were formulated for equal concentrations of neutral detergent fiber, crude protein, ether extract, and macrominerals. Treatments had no effect on dry matter intake, apparent total-tract nutrient digestibility, or milk production. The molasses coat, in either form, tended to decrease concentrations of odd-chain FA (2.25 and 2.31 vs. 2.35 g/100 g of FA for TC, LC, and CON, respectively) and unsaturated FA (31.4 and 31.1 vs. 32.1 g/100 g of FA) in milk. This could be indicative of a mild shift in ruminal fermentation away from propionate-producing bacteria toward fiber-digesting bacteria responsible for biohydrogenation of FA. The form of the molasses coating had few effects, but LC significantly decreased concentrations of total trans-C18:1 (2.04 vs. 2.30 ± 0.13 g/100 g of FA) and polyunsaturated FA (4.81 vs. 5.01 ± 0.17) compared with TC, implying that the liquid form slightly enhanced ruminal FA biohydrogenation. Furthermore, adding the DFM to the LC diet tended to increase the proportion of long-chain FA (FA >C16) and significantly increased the proportions of trans-C18:1 (2.22 vs. 2.04 ± 0.13 g/100 g of FA) and unsaturated FA (32.4 vs. 31.1 ± 0.7 g/100 g of FA), suggesting an inhibitory effect on ruminal biohydrogenation. Results suggest that coating cottonseed with a hardened molasses product does not significantly depress nutrient digestibility and may provide a convenient method of incorporating these ingredients into dairy rations.     

棉籽分离蛋白功能性质的研究

考察了棉籽各分离蛋白,包括清蛋白、球蛋白、醇溶谷蛋白及谷蛋白在棉籽蛋白中所占的比例,研究了各蛋白的功能性质,包括吸水性、吸油性、乳化性和乳化稳定性、起泡性与泡沫稳定性以及各蛋白的抗氧化活性。结果表明,谷蛋白为棉籽蛋白中的主要分离蛋白,棉籽清蛋白具有较高的吸水性、乳化性、乳化稳定性以及起泡性,吸油性相对较差,适用性相对较好,但在棉籽蛋白中含量较少,而谷蛋白的吸水性、乳化性、起泡性很差,具有一定的吸油性,适用性较差,但在棉籽蛋白中含量丰富,在抗氧化活性方面,各分离蛋白的抗氧化活性能力都较差,需要进行改性处理。     

以棉籽油为基料油的煎炸专用调和油煎炸品质的研究

以棉籽油为基料油,添加大豆油、菜籽油、棕榈油进行调配,制成煎炸专用的植物调和油。用制得的煎炸调和油进行不间断地煎炸薯条试验,考察煎炸油在煎炸过程中油脂色泽、理化指标及品质的变化情况。结果表明:煎炸调和油的脂肪酸组成合理,满足单不饱和脂肪酸/多不饱和脂肪酸=4.0:0.6的最佳摄入比例。煎炸过程中色泽变化较慢,极性组分超过27%限量的时间为67 h,酸价由(0.18±0.05) mg/g增加至(3.53±0.10) mg/g,羰基价由(9.42±0.12) meq/kg增加至(36.0±0.14) meq/kg,过氧化值和苯并(α)芘没有明显的变化趋势,丙烯酰胺未检出;与河北地区常用于煎炸的三级棉籽油46 h的煎炸寿命和较高的羰基价、过氧化值和苯并(α)芘相比,配制的煎炸调和油的煎炸寿命延长了18 h,稳定性提高了37%,煎炸薯条的平均含油率为18%煎炸感官效果好,可以作为一种新型煎炸调和油。     

酶法提取棉籽蛋白的工艺研究

以脱油脱酚棉籽粕为原料,研究了先用纤维素酶破坏其细胞壁,然后再用碱性蛋白酶酶解制备棉籽蛋白的生产工艺.通过单因素实验和正交实验对提取工艺参数进行优化.实验结果表明,纤维素酶的最佳酶解工艺条件为:酶解pH5.0,酶解温度50℃,加酶量0.4%,酶解时间2.0h.再选用碱性蛋白酶进行酶解,最佳工艺条件为:酶解pH8.5,酶解温度55℃,加酶量4.0%,酶解时间3.0h,此时蛋白提取率可达86.4%.     

烟秆替代部分棉籽壳作培养基栽培真姬菇的效果

研究了烟秆替代部分棉籽壳作培养基栽培真姬菇时菌丝生长、产量、生物转化率和经济效益等方面的表现,结果表明:烟秆能促进真姬菇菌丝生长,提高单产6.1%~12.8%,显著提高栽培原料生物转化率,节约真姬菇生产成本,其产品符合无公害食品标准。     

膜技术在制备棉籽蛋白多肽中的应用研究

采用微滤膜对棉籽蛋白酶解液进行除杂,首先根据膜通量及蛋白透过率选定合适的微滤膜,再考察了操作压力和温度对选定微滤膜通量的影响。结果表明:膜孔径为100nm的微滤膜较30nm微滤膜更适合本物料体系。且随着分离时间的延长,膜通量逐渐减小,至20min~30min后,膜通量趋于稳定;膜通量与压力和温度在一定范围内呈正相关。     

棉籽多肽缓解体力疲劳的研究

为了开发利用棉籽多肽资源,研究了棉籽多肽缓解体力疲劳活性。对小鼠体重、负重游泳时间、血乳酸含量、血清尿素氮、肝糖原、超氧化物歧化酶含量及丙二醛含量进行了测定。结果表明：棉籽多肽能延长小鼠的负重游泳时间,提高小鼠体内超氧化物歧化酶（SOD）的活性,降低小鼠体内丙二醛（MDA）的含量,提高小鼠肝糖原的储备量,降低小鼠运动后血清尿素氮和血乳酸水平,说明棉籽多肽具有较好的缓解体力疲劳效果。     

棉籽油的深度分提工艺

新疆棉籽油含有700 mg/kg的蜡质和26%～28%的固体脂，由于新疆气温多在零度以下，棉籽油在运输、储存和销售过程中易产生固化、沉淀、发朦，影响棉籽油的外观、食用和销售。为了保持包装棉籽油透明，提高棉籽油的质量和附加值，对棉籽油进行深度分提以脱蜡脱脂。介绍了棉籽油深度分提工艺，即在15 ℃脱除蜡质，在7 ℃分提出棕榈酸甘三酯，继续降温至-10 ℃分提出棕榈酸甘二酯、棕榈酸甘一酯及其他硬脂，最终得到在低温下保持透明的棉籽液油。     

棉籽油中脂肪酸不同的酯化方法与气相色谱-质谱分析

采用索氏提取法对棉花籽中棉籽油进行了提取,分别采用两种方法进行甲酯化处理,以气相色谱-质谱联用仪进行了分析,对它们的脂肪酸组成和含量进行了比较。结果表明:酯化方法1和酯化方法2分别鉴定出11种和7种脂肪酸,占棉籽油总量的96.16%和98.32%,方法1酯化的棉籽油中鉴定出主要脂肪酸为:棕榈酸占脂肪酸总量的27.26%,亚油酸占脂肪酸总量的40.24%,油酸占脂肪酸总量的14.27%;方法2酯化的棉籽油中鉴定出的棕榈酸占脂肪酸总量的27.12%,亚油酸占脂肪酸总量的48.00%,油酸占脂肪酸总量的15.51%。     

无腺体棉子蛋白色泽的测定

对无腺体棉子蛋白产品的色泽测定作了较全面的阐述,并初步解释了各种产品色泽差异的原因,同时与大豆蛋白产品的色泽进行了对比、分析