碱性蛋白酶制备水牛乳抗氧化活性肽酶解条件的优化

采用碱性蛋白酶,以水解度以及DPPH自由基清除率为评价指标,通过单因素以及正交实验优化水牛乳蛋白的酶解工艺,确定碱性蛋白酶制备水牛乳抗氧化活性肽的最佳酶解工艺为:底物质量分数5％,加酶量10 000U/g,酶解pH值为10.5,酶解时间2.5 h,温度为60℃;此时,酶解物水解度达30.46％±0.15％,DPPH自由基清除率达69.13％±1.22％.     

广西水牛原料乳微生物和理化指标分析

按不同种群从广西取80个水牛原料乳样品，通过理化和微生物指标检测，对水牛乳营养价值和安全性进行了分析比较．主要理化检测结果如下：脂肪7．32％，蛋白质4．71％，乳糖4．67％。固形物18．42％，灰分0．84％（均为质量分数），pH值为652，密度1.030g／mL。纯种河流型水牛摩拉和尼里-拉菲的脂肪、蛋白质、固形物、灰分舍量显著低于（P〈0.05）河流-沼泽型杂交水牛。微生物检测结果如下（对数值）：细菌总数5．69mL^-1，茅孢菌3．03mL^-1，乳酸菌4．79mL^-1，真菌1．80mL^-1，大肠菌群2．48mL^-1，大肠杆菌1．83mL^-1，金黄色葡萄球菌1.80mL^-1，所有样品中李斯特氏苗均未检出。地区间微生物指标差异较大。微生物含量均在可接受范围之内，但是致病菌的出现说明需要建立相关的卫生质量标准.     

Population structure and effects of inbreeding on milk yield and quality of Murrah buffaloes

To provide data for conservation, selection, and expansion programs of buffalo herds, this study evaluated the history of a population of Murrah buffaloes based on population structure and the effect of inbreeding on accumulated 305-d milk yield (MY), fat yield (FY), protein yield (PY), mozzarella production (MProd), and somatic cell score (SCS). The usefulness of including the individual inbreeding coefficient (F) or individual increase in inbreeding coefficient (ΔF) in the model to describe inbreeding depression was evaluated. Pedigree information from 8,054 animals born between 1976 and 2008 and 4,497 lactation records obtained from 12 herds were used. The realized effective population size was 40.10 ± 1.27, and the mean F of the entire population was 2.14%. The ratio between the number of founders and ancestors demonstrated the existence of a bottleneck in the pedigree of this population, which may contribute to a reduction of genetic diversity. The effect of F on MY, FY, PY, MProd, and SCS was −1.005 kg, −0.299 kg, −0.246 kg, −1.201 kg, and −0.002 units, and the effect of ΔF transformed to equivalent F (%) for a mean of 2.57 equivalent generations was −4.287 kg, −0.581 kg, −0.383 kg, −2.001 kg, and −0.007 units, respectively. The inbreeding depression observed may have important economic repercussions for production systems. The ΔF can be considered the better of the two indicators of inbreeding depression due to its properties that prevent underestimation of this effect. A designed mating system to avoid inbreeding may be applied to this population to maintain genetic diversity.     

水牛乳冰点与理化性质相关性的研究

对不同品种水牛乳进行为期一年的随机抽样测定,分析水牛乳冰点值与季节以及各主要理化性质间的相关性。结果表明,尼里-拉菲水牛乳一年中冰点均值范围为-0.536^-0.528℃之间;麽拉水牛乳为-0.537^-0.528℃之间;三品种杂交水牛乳为-0.543^-0.531℃之间;一代杂交水牛乳为-0.548^-0.533℃之间,各品种水牛乳冰点均值最低值出现在7、8月份,水牛乳的冰点值与水牛乳滴定酸度、蛋白质、脂肪、总固形物、乳糖+灰分总量存在Pearson极显著负相关性（p<0.01）,与水牛乳水分含量存在Pearson极显著正相关性（p<0.01）,与水牛乳中的体细胞数无显著相关性（p>0.05）。      

水牛家具革染色、复鞣及加脂工艺的体会

针对以不同的水牛蓝湿皮为原料皮的生产，在染色、复鞣及加脂工艺上作了一些研究，得出了较为合理的、并符合市场需求的工艺思路。     

Influence of variation in calcium content on casein micelle stability and techno-functional properties of buffalo milk

Changes in techno-functional properties of buffalo milk were evaluated due to variation in calcium content. Decalcification resulted in significant variation in ζ-potential, casein size, colour and η_app. However, calcium addition only influenced ζ-potential of milk. In case of acid gelation, the time and temperature required for coagulation decreased significantly for both calcium-depleted and -added milks. However, during chymosin gelation, only 20%–30% of calcium-depleted milk coagulated with an increased clotting time. Furthermore, calcium addition increased firmness, consistency and cohesiveness of both chymosin and acid-induced gelation.     

Short communication: Identification and technological characterization of yeast strains isolated from samples of water buffalo Mozzarella cheese

Sixty yeast cultures were isolated from samples of water buffalo Mozzarella, a popular “pasta filata” cheese, originating on 16 farms located in the provinces of Salerno, Caserta, and Frosinone (Italy). Strains were identified by means of 5.8S internal transcribed spacer rDNA PCR-RFLP combined with 26S rRNA gene partial sequencing and characterized for their ability to exert biochemical properties of technological interest. The recorded dominance of fermenting yeasts such as the lactose-fermenting Kluyveromyces marxianus (38.3% of the total isolates) and the galactose-fermenting Saccharomyces cerevisiae (21.6% of the total isolates) suggests that these yeasts contribute to the organoleptic definition of the water buffalo Mozzarella. The speciographic analysis revealed the presence of 7 other species rarely or never reported in a dairy environment belonging to the genera Pichia and Candida, whose role in Mozzarella cheese organoleptic properties need to be further investigated.     

False aneurysms in carotid arteries of cattle and water buffalo during shechita and halal slaughter

It has previously been shown that the cattle brain is supplied with blood via a basi-occipital plexus, in addition to branches from the carotid and basilar arteries. In addition it has been shown during conventional stunning and slaughter that the carotid arteries in cattle can develop false aneurysms at their severed ends and this can curtail exsanguination. This investigation examined whether false aneurysms can occur during religious slaughter, and during bleeding following electrical stunning that simultaneously induced a cardiac arrest. The prevalence of large (>3 cm outer diameter) false aneurysms in cattle carotid arteries was 10% for both shechita and halal slaughter. The prevalence of animals with bilateral false aneurysms (at least 2 cm in one artery and at least 3 cm diameter in the opposite artery) was 7% and 8% for shechita and halal slaughter, respectively. No false aneurysms occurred during bleeding in cattle that were electrically stunned and simultaneously developed a cardiac arrest. The combination of false aneurysms and collateral routes to the brain present a risk of sustained consciousness during religious slaughter in cattle.     

低温贮藏过程中水牛肉蛋白质的变化

目的:探明低温贮藏过程中水牛肉蛋白质的变化规律.方法:以水牛肉为研究对象,分别将肉样于4,-18,-60℃贮藏,测定贮藏过程中水牛肉的总蛋白质含量、表面疏水性、总巯基含量、游离巯基含量及羰基值,并对蛋白质指标之间的相关性进行分析.结果:不同低温贮藏过程中,随着贮藏时间的延长,水牛肉的总蛋白质、总巯基、游离巯基含量呈不断...