云南两个地方猪和杜洛克猪的营养成分比较

对火毛撒坝猪、高黎贡山猪、杜洛克猪的生长性状、胴体性能、肉质性状进行比较,为云南两个优质地方猪种的保护与开发利用提供理论依据.试验饲养火毛撒坝猪、高黎贡山猪、杜洛克猪各10头(5 ♂,5♀),至260日龄随机屠宰各猪种6头(3 ♂,3♀),测定其生长性状、胴体性能、肉质性状、肌肉组织学特性、脂肪酸、氨基酸和胆固醇,并进...     

牡蛎肉双酶复合水解和酸水解工艺

以牡蛎肉为原料,采用中性蛋白酶和菠萝蛋白酶同时水解技术和酸水解的方法,对牡蛎肉进行水解,通过对水解条件的研究确定双酶酶解的条件为:在料水比1∶8(g/mL)、pH7.0、温度50℃的条件下,先用中性蛋白酶(每克原料)2.3×10-5Kat水解4 h;然后依次用菠萝蛋白酶(每克原料)1.7×10-4Kat连续水解4 h。氨基酸分析结果表明:牡蛎肉中含有17种氨基酸,其中包括人体必需的7种氨基酸。     

The 15N-isotope dilution method for determining ileal endogenous nitrogen excretion in the young (10 kg liveweight) pig

A study was conducted with four crossbred 5-week-old castrated male pigs at an average body weight of 10 kg to determine the endogenous amino acid and nitrogen flows at the terminal ileum using the peptide alimentation and ¹⁵N-isotope dilution methods. The pigs were fitted with a post-valvular T caecal cannula and two indwelling blood catheters. They were fed a cornstarch-based semisyn'hetic diet formulated to contain enzymically hydrolysed casein (EHC) as the sole source of nitrogen at twice their maintenance requirement for energy. Digesta were centrifuged and ultrafiltrated after collection and the precipitate plus retentate fraction (mol wt > 10000) was used to determine the endogenous amino acid and nitrogen flows. To estimate the endogenous N flow at the terminal ileum of these EHC-fed pigs using the ¹⁵N-isotope dilution method a constant 10 day ¹⁵N-leucine infusion was performed at a daily rate of 5-04 mg of ¹⁵N-leucine (95% ¹⁵N enrichment) kg^?1 body weight. The mean ¹⁵N-enrichments above background for the trichloroacetic acid soluble blood plasma and ileal digesta nitrogen pools were 0.0249 and 0.0178, respectively. There were no statistically significant differences for ¹⁵N-enrichment excess between the days of ileal digesta collection. The results demonstrated that glutamic acid, aspartic acid, proline and serine formed about 50% of the total ileal endogenous amino acid flow. The total daily amount of endogenous amino acid flow at the terminal ileum was 6.2 g day^?1. The endogenous ileal N flows determined with the peptide alimentation and the ¹⁵N-isotope dilution methods were similar (P = 0.40) at 1.37 and 1.17 g day^?1, respectively. Endogenous N as a proportion of total N flow passing the terminal ileum was 83% and 72% for the peptide alimentation and the ¹⁵N-isotope dilution method, respectively. The study provides some support for application of the ¹⁵N-isotope dilution method with pigs.     

Effect of Conjugated Linoleic Acids in Pig Nutrition on Quality of Meat

Relationships among conjugated linoleic acid (CLA) in pig nutrition and carcass quality parameters (hot carcass weight, carcass yield and meatiness) and meat quality parameters (initial and pH value after 24, 48 and 72 h, temperature, drip loss, sensory color and marbling) were determined in pigs (crossbreeds Yorkshire x Landrace). Commercial CLA preparation containing 60% CLA isomers was included in the diet. No significant differences in performance parameters were found between pigs fed with CLA and control group during 60 days period. CLA supplementation in feed significantly increased SFA and decreased MUFA and PUFA fraction in pig muscles.     

鸡骨渣水解用酶的筛选

以鸡骨架高压蒸煮后的鸡骨渣为原料,研究不同蛋白酶对其酶解效果及酶解产物氨基酸的组成。结果表明：风味蛋白酶具有较强的水解能力,水解度(DH)达到23.15%;其酶解液澄清度高并具有较强的鸡鲜味;其酶解产物中7 种必需氨基酸含量为68.90%,谷氨酸、甘氨酸、天冬氨酸和精氨酸等风味氨基酸分别占氨基酸总量的5.09%、1.40%、2.59% 和10.45%。     

Endogenous lysine and other amino acid flows at the terminal ileum of the growing pig (20 kg bodyweight): The effect of protein-free,synthetic amino acid,peptide and protein alimentation

Twenty-four crossbred pigs of 15 kg initial bodyweight were fed four semi-synthetic diets for 10 days according to a completely randomised design. The study aimed to determine the effects of state of body nitrogen balance and the presence of dietary peptides and protein in the digestive tract on the excretion of endogenous amino acids from the ileum of the pig. Endogenous lysine excretion was determined for pigs given a protein-free (PF) diet, an enzymically hydrolysed casein- (EHC), a zein- (ZN) or a synthetic amino acid- (SAA) based diet. Digesta from the EHC-fed animals were centrifuged and ultrafiltered after collection and the precipitate plus retentate fraction was used to determine the endogenous flows. Such processing excludes unabsorbed dietary amino acids from the measure of endogenous loss. ZN is naturally deficient in lysine and tryptophan and these two amino acids were omitted from the synthetic amino acid-based diet to allow direct measurement of endogenous lysine flow. Pigs given the ZN and SAA diets received free lysine and tryptophan orally throughout the study except for the final 2 days of the study, when these amino acids were infused intravenously. Endogenous flows for amino acids other than lysine were determined for pigs given the PF and EHC diets. On the final day of the study the pigs were given their daily dietary allowance hourly and killed 10 h after the start of feeding. Digesta were collected from the terminal ileum (20 cm anterior to the ileo-caecal junction) and endogenous flows were determined by reference to the marker chromic oxide. The mean endogenous ileal lysine flows for the ZN- and EHC-fed pigs were not significantly different (overall mean, 419 mg kg^?1 dry matter intake), but were higher (P < 0.05) than those for the PF- and SAA-fed pigs (overall mean, 268 mg kg^?1 dry matter intake) whose mean flows were not significantly different from each other. The mean endogenous ileal flows for amino acids other than lysine were higher (P < 0.05) for the EHC-fed pigs compared to the animals on the PF diet, except for proline, glycine and arginine. The similar endogenous ileal lysine excretion for pigs receiving a SAA-based diet and in positive body nitrogen balance, and PF-fed pigs in negative body nitrogen balance, indicates that negative body nitrogen balance per se does not lead to a lowered endogenous ileal excretion. It would appear, however, that the presence of dietary peptides or protein in the gut increases amino acid excretion at the terminal ileum above that found with PF or SAA alimentation. Consequently, endogenous ileal amino acid flow in the pig may be underestimated when determined by the traditional PF method.     

脱皮双低菜籽粕制取复合氨基酸工艺研究

该文研究以脱皮双低菜籽粕为原料制备复合氨基酸,通过正交试验确定双低菜籽粕水解最佳工艺是:硫酸浓度15％,固液比(W/V)1∶6,水解时间10 hr;适宜脱色条件为:活性炭浓度2％、脱色温度90℃,脱色时间30 min;复合氨基酸得率为46.65％,纯度为55.91％。     

环文蛤肉复合酶的水解工艺初探

以环文蛤为原料,采用酶水解的方法制备环文蛤肉水解液。先选用中性蛋白酶、碱性蛋白酶、木瓜蛋白酶和菠萝蛋白酶,分别对环文蛤肉进行单酶水解实验;并用复合酶解新技术对环文蛤肉进行水解研究。实验结果表明:3种酶复合水解的最佳工艺为:在料水比1:8(m/v)、pH7.0、50℃条件下,用中性蛋白酶6000U/g原料先水解4h,再依次使用碱性蛋白酶4000U/g、菠萝蛋白酶12500U/g连续水解4h后水解度达到43.27%。复合酶解液中游离氨基酸含量丰富,约为117.89μg/mL,其中必需氨基酸占51.39%。环文蛤肉经复合蛋白酶水解,适当调配可制作营养丰富、海鲜风味浓郁、具有一定保健功能的口服液。     

酶解鹅血制备高氨基酸血红素

利用Box-Behnken中心组合实验设计对碱性蛋白酶水解鹅血提取高氨基酸鹅血血红素的工艺条件进行了优化。结果表明:对水解度的影响次序为酶浓度>水解温度>水解时间>溶液p H。鹅血提取高氨基酸血红素的最佳酶解工艺参数:酶浓度5%,温度50℃,p H8.80,水解时间5.15 h,水解度为14.36%±0.18%。水解后,水解液中血红素含量为1.210 mg/m L,铁离子的含量为90.42μg/m L。      

双水相系统中酶法水解明胶制取氨基酸的研究

在PEG-盐双水相系统中,进行了蛋白酶催化明胶水解制取混合氨基酸的研究。双水相系统组成为20％PEG1540、10％磷酸钾盐、pH7．5时,加入3％碱性蛋白酶发酵液和35％明胶,45℃下水解10h,转化率达到83．2％。酶分配于顶相,水解产物分配于底相,混合氨基酸的总收率为76．7％。水解产物中混合氨基酸由13种氮基酸组成,其中7种为必须氨基酸。     

主要粮食饲料资源氨基酸消化利用率的研究

采用8头初始体重为(27．2±2．3)kg、在回肠末端装有简单T型瘘管的杜长大三元杂交公猪, 手术康复后随机分成2组,每组4头,每组采用同一豆粕-玉米淀粉基础日粮,按拉丁方设计,用于测定豆粕、棉粕、菜粕、稻谷、油糠、统糠和玉米7种饲料原料的回肠和粪氨基酸消化率。结果表明:所测氨基酸平均表观消化率回肠比粪低5—8个百分点(P<0．05);稻谷氨基酸表观消化率比玉米低5％;所测原料氨基酸表观消化率与中国饲料数据库等报道结果基本吻合。     

桑椹酒中氨基酸含量分析

建立采用氨基酸分析仪测定桑葚酒中18种氨基酸含量的分析方法。样品经氮吹去除乙醇处理后,采用酸/碱水解将其中的蛋白质和肽类化合物转化成游离氨基酸,采用氨基酸分析仪测定其含量。18种氨基酸在2.5～250.0 μmol/L的浓度范围内,峰面积和浓度呈良好的线性关系,相关系数R为0.998 8～0.999 9,检出限均＜0.50 mg/L,各化合物的加标回收率为72.8%～104.0%,重复性试验结果相对标准偏差（RSD）均＜5.0%。该方法可靠、准确、重现性好,为桑椹酒的营养价值评价提供参考资料。     

对虾头的酶解研究

以南美白对虾的虾仁加工废弃物--虾头为原料,对其最佳作用酶及酶解工艺进行了研究,并分析了酶解前后各游离氨基酸含量.结果表明:在几种实验酶中酶解效果最好的是木瓜蛋白酶,其最适作用条件为物液比1:0.6,初始pH7.5、酶用量775U/g、温度42℃、酶解3h,此条件下对虾头蛋白的水解度可达到64.82%;为解决酶解物的苦味问题,将木瓜蛋白酶与复合风味酶1:1(质量比)复合后用酶总量775U/g,在木瓜蛋白酶的最适作用条件下酶解3h,酶解液无苦味且具诱人、浓郁的海虾风味,水解度为58.01%;与对虾头浆液相比,酶解液中各游离氨基酸含量均大大增加,其中谷氨酸增幅及含量均为最大.     

秋刀鱼抗氧化肽制备及其抗氧化活性的研究

本文选择胰酶对秋刀鱼蛋白进行酶解,以蛋白质利用率和氧化自由基吸收能力(ORAC值)为指标,运用响应面分析法优化秋刀鱼蛋白制备抗氧化肽的酶解工艺,并且对酶解产物的特性进行了研究。结果表明:最优酶解条件为加酶量1085 U/g蛋白,水料比3:1,酶解时间8 h时,此时蛋白质利用率和ORAC值分别为76.86%和883.40μmol Trolox equivalent/g。秋刀鱼酶解产物的总氨基酸含量为4576.69 mg/100 mL,其中游离氨基酸和肽态氨基酸分别占34.28%和65.31%;总氨基酸中必需氨基酸占34.76%,抗氧化活性氨基酸和支链氨基酸占26.25%,说明秋刀鱼酶解产物具有较高的营养价值。秋刀鱼酶解产物中相对分子质量在1000~3000 Da之间的组分最多,占44.18%。秋刀鱼酶解产物清除DPPH·的IC50值为3.32 mg/mL,清除O2-·的IC50值为5.08 mg/mL,当秋刀鱼酶解产物的蛋白浓度为10 mg/mL时,其吸光值为0.67,说明秋刀鱼酶解产物具有较高的抗氧化活性。     

一种用于火腿加工的“橡子猪”后腿原料品质研究

通过对一种以橡子为补充日粮的河南杂交黑猪(以下简称     

多管藻（P.urceolata）复合氨基酸营养液的研制

本研究就多管藻（Polysiphonia urceolata)的脱色方法及酶解工艺条件等进行了探讨。结果表明原料脱色用KMnO4效果较好,酶解的最佳工艺条件是使用中性蛋白酶与胰蛋白酶联合酶解法,总加酶量为5‰（w/w)在45℃水解4h后,再加0．2％NaOH碱解2h,蛋白质水解度和氨基酸转化率分别高达80．4％和39．6％。     

微小杆菌属SWJS2蛋白酶对鱼肉酶解特性的研究

本文以凤尾鱼、草鱼为原料,研究了本实验室新筛选的微小杆菌属SWJS2所产蛋白酶对凤尾鱼和草鱼蛋白的酶解特性。结果表明:微小杆菌属SWJS2蛋白酶对凤尾鱼和草鱼的最适酶解温度分别为40℃和45℃。微小杆菌属SWJS2蛋白酶对凤尾鱼的酶解效果优于木瓜蛋白酶,酶解12 h时蛋白回收率为72.64%,水解度达21.38%,ORAC值与还原力均高于木瓜蛋白酶的酶解产物。微小杆菌属SWJS2蛋白酶酶解草鱼的蛋白回收率及抗氧化性能则不及木瓜蛋白酶,但水解度较高。微小杆菌属SWJS2蛋白酶对两种鱼肉的酶解产物中游离氨基酸组成与6种商业蛋白酶有明显差异,亮氨酸、丙氨酸、缬氨酸、苯丙氨酸、异亮氨酸含量显著高于商业酶,而精氨酸、天冬氨酸、苏氨酸、丝氨酸、天冬酰胺等的含量较低。说明其优先酶切位点与6种商业蛋白酶有较明显的差异。     

秋刀鱼蛋白酶解物的制备及氨基酸评价

采用正交实验法优化制备秋刀鱼蛋白酶解物的最适工艺条件，探讨了影响秋刀鱼蛋白酶水解的主要因素。实验表明，最适的酶解条件为：复合酶与风味酶之比为1：3，复合酶量为0．100g／25g鱼肉，酶解温度为50℃，酶解时间为7h。在此条件下，秋刀鱼蛋白水解度为45．5％，总游离氨基酸含量为1800．53mg／100mL。经高效液相色谱分析，在水解产物中约50％的氨基酸为具有较高营养价值的抗氧化活性氨基酸和支链氨基酸。