准格尔双峰驼驼乳脂肪酸组成的季节变化

对20峰准格尔双峰驼乳脂肪酸质量分数的季节变化进行了分析,结果表明,准格尔双峰驼枯草前期乳中饱和脂肪酸(SFA)的质量分数显著高于其他三季,而其他三季间则差异均不显著;准格尔双峰驼乳中单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)的质量分数没有显著的季节差异。准格尔双峰驼乳致动脉粥样硬化指数低于牛乳,饱和脂肪酸和不包脂肪酸的比例适当,比牛乳驼乳脂肪酸对人体具有较高的营养价值。     

不同泌乳时间内内蒙古阿拉善双峰驼驼乳化学组成变化分析

本研究对10匹内蒙古阿拉善双峰驼驼乳的化学组成进行了分析。结果表明，第1次所挤初乳中总干物质为20．16％，在2-30d内变化范围为17．42％18．22％，到90d下降为14．31％。第1次所挤初乳中蛋白质为14．23％，12h后下降到9．63％，之后进一步下降，在7、15、30及90d分别为7．40％、5．32％、4．87％和3．55％。乳糖含量在1～90d泌乳期内变化较小，为4．24％-4．44％。第1次所挤初乳脂肪含量为0．27％，到24h增加到4．18％，30d时为6．91％，90d又下降到5．65％。第1次所挤初乳中灰分含量为1．22％，到12h下降到0．99％，在90d泌乳期内稳定在0．82％～0．98％范围内。第1次所挤的初乳中，WPN占总氮58．74％，CN占总氮38．57％，NPN仅占总氮的2．69％；24h，WPN、CN及NPN分别占总氮的32．54％、65．08％及2．38％。随泌乳进行，驼乳氮分布中CN逐渐升高，WPN逐渐降低，2-90d NPN占总氮变化较小，为5．26％～7．89％。驼乳中C12：0～C18：0偶数长链饱和脂肪酸占总脂肪酸的57．54％，其中C16：0、C18：0及C12：0分别占总脂肪酸的30．12％、15．15％和11．49％，C18：1～C18：3长链多不饱和脂肪酸占总脂肪酸组成的30．25％，其中以C18：1脂肪酸为主，为26．05％。第1次所挤的初乳中钙、磷含量最高，分别为222．58mg／100g和153．74mg／100g；钙、磷、钠、钾及氯在3～90d变化范围分别在154．57～186．87、116．82～141．67、59．5～79．5、150．0～191．0和80．9～152．0mg／100g。初乳中VA、VC含量低于霄乳，VE、VB1高于常乳，VD、VB2及VB6与常乳相近。90d驼乳中VA、VE、VB1、VB2、VB6、VC和VD分别为0．97mg／L和1．45、0．124、1．24、0．54和29．60mg／L和692IU／L。     

改性聚乳酸薄膜对阿拉善双峰驼肉的自发气调保鲜

为延长阿拉善双峰驼肉的货架期,制备了20μm和40μm两种厚度的聚乳酸(Poly(L-lactic acid),PLLA)/聚对苯二甲酸-己二酸-1,4-丁二醇酯(Poly(butylene adipate-co-terephthalate),PBAT)共混薄膜,测试了其机械性能和透气性能,并将其应用于驼肉的均衡自发气调包装。以菌落总数、挥发性盐基氮、色值(a*)和感官为品质指标评价薄膜对驼肉的保鲜效果。结果表明:与纯PLLA薄膜相比,PLLA/PBAT薄膜的氧气和二氧化碳透过率分别增大了31.4%和309.8%,断裂伸长率提高了17倍以上。在贮藏期间,PLLA/PBAT包装内形成了稳定的气体组分,有效延缓了驼肉的菌落总数和挥发性盐基氮的增长,使其新鲜的红色和良好的感官得以维持。其中,20μm的薄膜包装的肉样货架期延长到20 d以上,优于40μm的薄膜包装的肉样(不足15 d)和裸露的肉样(不足3 d)。     

内蒙古阿拉善双峰驼驼乳IgG的分离纯化及其热稳定性研究

本文采用硫酸铵沉淀法两次沉淀乳清蛋白,并结合离子交换层析法,从双峰驼初乳中分离纯化驼乳IgG。再用SDS-PAGE鉴定其纯度,测定其分子量。然后用分离纯化的驼乳IgG免疫家兔,制备效价至少为1:32的兔抗驼IgG抗血清。内蒙古阿拉善双峰驼驼乳分别于65、75、85和100℃加热30min,用SDS-PAGE检测驼乳中IgG的变性程度。同时采用单向免疫扩散法测定驼乳中IgG的活性。结果表明,于75℃,加热30min,驼乳IgG的活性丧失68.9%,而参考值的牛乳IgG活性则完全丧失。因此,驼乳IgG的热稳定性比牛乳IgG的热稳定性高。     

阿拉善双峰骆驼肉品质分析

通过二因子多水平重复试验对阿拉善双峰骆驼肉不同性别(公、母)和不同部位(股二头肌、臂三头肌、背最长肌)肉品质进行了测定分析。结果表明,阿拉善双峰驼肉除嫩度稍差外,pH值适中、肉色鲜红、大理石纹分布均匀、系水力和熟肉率较高,具有高水分、高蛋白、低脂肪的特点,是人类较理想的动物性食品。不同性别驼肉除母驼肌肉中水分含量显著高于公驼外(P<0.05),其他均无显著差异(P>0.05)。不同部位驼肉除大理石纹、剪切力、水分、蛋白质和脂肪含量在不同部位间存在极显著差异(P<0.01)或显著差异(P<0.05)外,其他均无显著差异(P>0.05)。     

阿拉善双峰驼宰后僵直前期肌肉物性变化及水分含量的研究

研究了不同年龄的阿拉善双峰驼宰后不同部位肌肉中的水分含量和剪切力值差异,并与牛、羊肉进行了对比。主要采用直接干燥法和质构仪直接测定方法,分别对3岁、5岁、8岁、11岁和13岁的阿拉善双峰驼的前腿肌肉、后腿肌肉和背最长肌中的水分含量和剪切力值进行了测定分析。结果表明,阿拉善双峰驼宰后不同部位肌肉的剪切力值介于5.53~12.84 kg之间,不同年龄双峰驼肌肉的剪切力值除11岁与13岁之间差异不显著外,其他年龄之间差异均显著(P0.05),且肌肉剪切力值随年龄的增长而增大;3个部位之间的剪切力值差异显著(P0.05),且背最长肌的剪切力显著低于前腿和后腿。肌肉中水分含量介于68.24%~78.62%之间,表现出双峰驼年龄越大肌肉中水分含量越低的趋势,且3个部位之间的水分含量差异显著(P0.05),后腿肉水分含量高于前腿肉,前腿肉高于背最长肌。以3岁、5岁和8岁龄的阿拉善双峰驼分别与当地24月龄牛与12月龄羊比较分析可知,3岁骆驼肉的水分含量高于牛羊肉,其剪切力值也较低,而从5岁以后肌肉剪切力值比牛羊肉高,肌肉的水分含量与剪切力值较牛羊肉均呈现显著差异(P0.05)。     

阿拉善双峰驼酸驼乳中乳酸菌的分离鉴定及耐酸和耐盐研究

以采自内蒙古阿拉善地区的传统发酵阿拉善双峰驼酸驼乳为材料,采用乳酸细菌培养基(MRS)对其中的乳酸菌进行初分离,经平板划线法纯化后,借助16 SrDNA的序列分析法进行分子鉴定,并对其耐酸性、产酸能力、最适pH值及耐盐性等性质进行研究。结果表明,分离纯化出3株疑似优势乳酸菌,分别为乳杆菌属的Lactobacillus plantarum strain KC28、Lactobacillus plantarum strain K25和Lactobacillus sp. D1501。3株菌均为革兰氏阳性,耐酸性较好,产酸性能适中;最适培养p H值为6.5。     

Changes in chemical composition of Alxa bactrian camel milk during lactation

Changes in chemical composition of Alxa bactrian camels reared in Inner Mongolia (China) during lactation were investigated. Colostrum and milk samples from 10 nomadic female camels in their first season of lactation were collected periodically from parturition until 90 d postpartum (PP). The average contents of gross composition were 14.23% protein, 4.44% lactose, 0.27% fat, 0.77% ash, and 20.16% total solids in colostrum at 2 h PP, and the respective mean values were 3.55, 4.24, 5.65, 0.87, and 14.31% for regular milk on d 90. A 15-fold increase was shown in fat content during the first 24 h, whereas a sharp decrease was shown during the first 12 h of lactation in protein, ash, and total solids contents. Variation in lactose content was small (4.24 to 4.71%) throughout the study period. Total N, nonprotein N, casein N, and whey protein N were found to be 2.23, 0.06, 0.86, and 1.31 g/100 mL for the colostrum at 2 h PP; and 0.56, 0.04, 0.45, and 0.07 g/100 mL for the milk at 90 d PP. Percentages of caseins increased steadily, whereas whey proteins declined gradually until 3 mo of lactation. Gas liquid chromatography analysis of milk fat showed that the content of even-numbered saturated fatty acids (C_12:0-C_18:0) in camel colostrum (2 h to 7 d PP) was lower than that of regular milk (15 to 90 d PP). The predominant saturated fatty acids were C_14:0, C_16:0, and C_18:0, regardless of the stage of lactation. There was a considerable level of polyunsaturated fatty acids (mainly C_18:1) in Alxa camel's milk fat. The levels of Ca, P, Na, K, and Cl were 222.58, 153.74, 65.0, 136.5, and 141.1 mg/100 g, respectively, at 2 h PP; the values of the minerals were 154.57, 116.82, 72.0, 191.0, and 152.0 mg/100 g, respectively, for the regular milk on d 90. The levels of vitamins A, C, E, B₁, B₂, B₆, and D were 0.97, 29.60, 1.45, 0.12, 1.24, 0.54 mg/L, and 640 IU/L, respectively, in Alxa camel milk at 90 d PP. Vitamin A and C contents were higher and vitamins E and B₁ were lower than those in colostrum. Sodium dodecyl sulfate-PAGE and densitometry results demonstrated that Alxa camel colostrum is rich in immunoglobulins, serum albumin, and 2 unknown fractions, which are reduced in amount (%) within 2 d of lactation. It seems that there is lack of β-lactoglobulin in Alxa camel milk, whereas casein and α-lactalbumin start at a low level and increase gradually until they reach their regular levels in the milk.     

Fatty acid composition of the meat and fat of the one-humped camel (camelus dromedarius)

The fatty acid composition of lean raw meat taken from the hind leg of seven young (1-3 years of age) male one-humped camels (Camelus dromedarius) has been determined by capillary gas-liquid chromatography; fat samples taken from the hump of these seven camels were also analysed. The saturated fatty acids in the meat account for 51·5% of the total fatty acids, while the monosaturated and polyunsaturated chains constitute 29·9 and 18·6%, respectively. The major fatty acids in camel meat are palmitic (26·0%), oleic (18·9%) and linoleic (12·1%), with smaller amounts of other fatty acids, both normal and branched, that range in chain lengths from C(14) to C(22). The fatty acids of dromedary fat are dominated by saturated even-numbered chains with smaller amounts (5·4%) of odd-numbered normal and branched chains. The main fatty acid of the hump fat is palmitic (34·4%) followed by oleic (28·2%), myristic (10·3%) and stearic (10·0%).     

Fatty acid composition of goat diets vs intramuscular fat

Twenty Boer x Spanish goats, at the age range of 90–118 days, were assigned to two dietary treatments, with 10 animals fed a grain ration (G) and the other 10 grazed in rangeland. The grain ration contained sorghum grain (67.5%), cottonseed hulls, dehydrated alfalfa meal, cottonseed meal, soybean meal, molasses, and mineral and vitamin supplements. Animals were slaughtered at the age range of 206–234 days. Intramuscular fat (IF) and the diet specimens — representative samples of G and the parts of range plants (RPs) that goats were expected to have consumed — were analyzed for fatty acid composition. The percentage of 16:0 was higher in RPs than in G, but not different between IF from range goats and that from grain-fed goats. Total unsaturated fatty acid (UFA) percentage was higher in G than in RPs. The major UFAs were 18:2 and 18:3 in RPs, and 18:1 and 18:2 in G. In IF, 18:1 constituted more than two-thirds of UFAs, regardless of diet type.     

Fatty acid and glyceride composition of Astrocaryum vulgare kernel fat

The kernel composition, lipid classes, fatty acid composition, fatty acid distribution on triglycerides and triglyceride composition of kernel fat from Astrocaryum vulgare Mart palms grown in Nigeria have been studied. Kernels had a high fat content. Lauric acid was the predominant fatty acid in the whole fat and was also the major fatty acid in the triglycerides and in the 2-monoglycerides derived from them by pancreatic lipase hydrolysis. All the fatty acids exhibited a preference for the 1-and-3, positions of triglycerides, except for lauric which showed a preference for the 2-position and oleic which exhibited a random distribution. The trisaturated triglycerides were the predominant triglyceride type and the fatty acid composition of the various triglycerides suggested an absence of completely unsaturated triglycerides.     

驼峰油精炼及其抗氧化性的研究

以湿法熬油得到的驼峰原油为原料,通过酸法脱胶、碱炼脱酸、吸附脱色和真空水蒸气脱臭获得驼峰精炼油,对精炼前后驼峰油理化性质进行了测定。同时,采用Schaal试验法探讨精炼驼峰油的氧化稳定性,并预测其货架期。结果表明:精炼后驼峰油的色泽由浅棕黄色变为浅黄色,酸价(KOH)由(1. 27±0. 14) mg/g降至(0. 083±0. 006) mg/g,碘值、皂化值无显著变化,精炼驼峰油碘值(I)和皂化值(KOH)分别为(45. 88±0. 84) g/100 g和(204. 07±2. 04) mg/g;精炼驼峰油的氧化稳定性低于驼峰原油,所研究的抗氧化剂中茶多酚的抗氧化效果最佳,其最适添加量为0. 02%,可使精炼驼峰油在20℃下的货架期至少延长到560 d。     

Fatty acid composition of subcutaneous fat of sheep grazed on eight different pastures

The levels of eight long chain fatty acids (14:0, 16:0, 16:1 17:0, 17:1, 18:0, 18:1, 18:2) were measured in the subcutaneous fat of S.A. Mutton Merino wethers (5 months old, 20-25 kg live mass, 8 per treatment) and, including 18:3, in eight pastures grazed for 84 days (maize stubble, Z. mays; Triticale; L. multiflorum; L. perenne; D. glomerata; D. eriantha; C. dactylon; M. sativa). Respectively, percentage fatty acid contents of subcutaneous fat and pastures were 14:0 5·04 ± 0·86 and 0·67 ± 0·37, 16:0 22·85 ± 0·81 and 17·83 ± 3·00, 16:1 2·07 ± 0·22 and 2·42 ± 1·17, 17:0, 1·68 ± 0·04 and 0·42 ± 0·16, 17:1 0·75 ± 0·06 and 0·17 ± 0·19, 18:0 25·94 ± 2·02 and 4·95 ± 1·68, 18:1 32·27 ± 0·93 and 8·12 ± 11·70, 18:2 1·59 ± 0·36 and 15·89 ± 5·16, 18:3 measured in pastures only 34·51 ± 15·91. The palmitoleic acid (16:1) content of pastures increased (P < 0·05) as the ether extractable lipid content of the pastures increased. Pasture treatments influenced the levels of 14:0, 17:1 and 18:2 highly significantly (P < 0·01) and of 18:0 significantly (P < 0·05). Increasing levels of fatness of ribcut samples were associated with a decrease in 14:0 and an increase in 17:1 (P < 0·01) and an increase in 18:2 (P < 0·05).     

Effects of age on fatty acid composition of the hump and abdomen depot fats of the Arabian camel (Camelus dromedarius)

This study aimed to quantify concentrations of fatty acids in the hump and abdomen fats of three different age groups of camel. Hump and abdomen fats were extracted from eight each of one-humped camels (Camelus dromedarius) of three age groups: group 1 (<1 year old), group 2 (1-3 years old) and group 3 (>3 years old). The fatty acid methyl ester concentrations of these fats were determined by gas-liquid chromatography (GLC). The percentage of fat in the hump (H) and abdomen (A) fats was significantly (P<0.05) lower for group 1 (H 92.0% and A 94.3%) than for group 2 (H 97.4% and A 97.2%) and group 3 (H 97.6% and A 97.5%), on a dry matter basis. Hump and abdomen fats from the three different groups had similar fatty acid patterns with more saturated than unsaturated fatty acids. The saturated fatty acids in the hump fats accounted for 58.3, 67.6, and 63.0% of the total fatty acids for groups 1, 2 and 3, respectively; group 1 had significantly (P<0.05) lower saturated and higher unsaturated fatty acid concentrations than group 2. The iodine numbers were significantly (P<0.05) higher in group 1 than either group 2 or 3. Palmitic acid (C16:0) was the major fatty acid in hump fat with 32.06, 32.90 and 34.37%, followed by oleic acid (C18:1) 33.65, 21.66 and 28.91.0% and stearic acid (C18:0) 18.85, 24.13 and 20.74% for groups 1, 2 and 3, respectively. Group 1 had significantly higher (P<0.05) oleic acid and lower stearic acid concentrations than group 2. The melting point of both hump and abdomen fats varied between the age groups. This study indicated that age has an effect on the fatty acid composition and the melting point of hump and abdomen fats in one-humped Arabian camels.     

Fatty acid composition and characteristics of Pentadesma butyracea fat extracted from ghana seeds

Recent interest in the development of the tallow tree (Pentadesma butyracea S) as an oil-tree crop has stimulated agronomic and chemical studies of the tree and the fat obtained from its seeds. Tallow fat extracted from local seeds has been analysed for its chemical and physical constants and fatty acid composition. These characteristics have been compared with those of the better known cocoa butter and shea butter. Dry tallow kernels, shea butter kernels and cocoa beans contained 50, 52.1 and 53.4% fat, respectively. Tallow fat and shea butter are similar in several of their characteristics, particularly slip point, saponification number, solidification point and fatty acid composition; but tallow fat has a much lower unsaponifiable matter content (1.5–1.8%) than shea butter (7.3–9.0%). Both are markedly different from cocoa butter and cocoa butter replacement fats in respect of their melting points and fatty acid composition. Cooling curves of 3:1, 1:1, and 1:3 mixtures of tallow fat and cocoa butter indicate poor compatibility between the two fats.