凝固型无糖水牛奶酸奶的研制

以水牛奶为主要原料,用安赛蜜与蛋白糖混合的甜味剂代替蔗糖来生产的无糖高蛋白凝固型酸奶,在口感上与蔗糖为甜味剂的酸奶相近,能被大部分消费者接受.通过单因素及口感测试,得到最优添加量为:安赛蜜0.03% 蛋白糖0.03%.     

无蔗糖酸奶的研制

本试验研究了各种甜味剂对酸奶质量的影响，在此基础上确定了甜味剂的配比并进一步研究了无蔗糖酸奶的配方。结果表明：甜味剂的配比为三氯蔗糖25％、AK糖25％、阿斯巴甜50％，酸奶的最优配方组合为发酵剂CHR HANSEN YC380、乳固体的含量11％、蔗糖的替代比为100％。最后比较无蔗糖酸奶和普通酸奶的感官品质。发现它们无实质性差异。     

无蔗糖调味乳工艺优化

研究不同甜味剂对调味乳质量的影响,在此基础上确定甜味剂的配比并进一步研究无蔗糖调味乳的配方。结果表明：甜味剂配比为三氯蔗糖25%、纽甜25%、阿斯巴甜50%;调味乳的最优配方组合为稳定剂0.2%、核桃粉0.6%、蔗糖替代比100%。比较无蔗糖调味乳和普通调味乳的感官品质,无实质性差异。     

最陡梯度法确定搅拌型酸乳复合增稠剂研究

在对果胶、变性淀粉、明胶三种酸乳增稠剂增稠搅拌型酸乳的三因素三水平正交试验基础上采用最陡梯度法进行复合增稠优化.试验结果表明:三因素增稠搅拌型酸乳的最优复合配方为果胶、变性淀粉、明胶的添加量分别为1%、1.6%、1.5%,总的添加量为4.1%,此时酸乳的粘度达到0.397 Pa·s.     

香菇酸奶的研制

本试验以鲜牛乳和鲜香菇为主要原料，按凝固型酸乳的加工工艺，生产出风味、组织状状良好、集香菇和酸乳营养保健的一体的香菇酸乳。试验中以香菇添加量、白糖添加量、奶粉添加量和菌种添加比例作为影响香菇酸乳质量的因素，采用L9（34）正交优选法优选出最优组合。结果表明，牛乳添加15％的鲜香菇汁，8％的白硝糖和3％的奶粉，杀菌、冷却后换接种2％的乳酸菌发酵剂（保加利亚乳杆菌：嗜热乳酸链球菌＝1：1），在42℃下恒温培养3.5-4h至凝固，制成一种香菇酸乳。并对香菇酸乳的感官性能、营养成分进行了分析，为成品推向市场提供科学依据，并为我国香菇的开发和开拓乳制品新产品提供新途径。     

铁皮石斛多糖发酵乳饮料工艺优化

以铁皮石斛多糖提取液、脱脂乳粉为主要原料,发酵制备铁皮石斛多糖酸乳饮料.铁皮石斛多糖乳饮料的最佳工艺参数(以质量分数计):50％铁皮石斛多糖溶液添加量10％、蔗糖添加量7％、发酵剂(保加利亚乳杆菌:嗜热链球菌=1:1)接种量0.10％,在发酵温度42℃条件下发酵6h,所得铁皮石斛多糖酸乳饮料风味最佳.     

桦褐孔菌多糖对牦牛酸乳品质的影响

通过液体深层发酵技术生产桦褐孔菌并提取其多糖,以感官评分与滴定酸度为依据,通过单因素试验确定最佳多糖添加量,进一步优化桦褐孔菌多糖牦牛酸乳的生产工艺参数,在最优工艺参数条件下研究桦褐孔菌多糖添加对牦牛酸乳品质的影响。结果表明：桦褐孔菌多糖添加量为0.4%时,牦牛酸乳的感官评分最高且酸度较为适口;采用正交试验优化牦牛酸乳的生产条件,获得最佳生产工艺为嗜热链球菌G2与副干酪乳杆菌L9发酵剂复配比1∶1、发酵时间14 h、发酵温度38 ℃、蔗糖添加量8 g/100 mL,该条件下,添加桦褐孔菌多糖的牦牛酸乳中乳     

酸枣汁酸乳菌饮料的工艺及稳定性研究

本文主要研究酸枣汁酸乳饮料的配方组成及琼脂、CMC复配效果对饮料稳定性的影响。实验结果表明：采用25％酸乳量、10％枣汁量、10％蔗糖量、0.35％稳定剂（CMC：琼脂=2.5：1）配制的酸枣汁酸乳饮料具有较好的口感和稳定性。     

3种变性淀粉的糊化特性及其在长保质期酸乳中的应用

研究3种变性淀粉(物理变性淀粉(physical modified starch,PMS)、乙酰化二淀粉磷酸酯(acetylated distarch phosphate,ADSP)、羟丙基二淀粉磷酸酯(hydroxypropyl distarch phosphate,HDSP))的糊化特性及其在长保质期酸乳中的应用.结果表明:3种淀粉糊化后都保持着颗粒状态,具有较强的耐剪切性,其中ADSP和HDSP比PMS更耐剪切,具有更高的糊化温度,更难糊化.添加3种质量分数2％的变性淀粉均能够显著提高酸乳的黏度和持水力,增强其黏弹性和屈服应力,提高酸乳的贮藏稳定性.ADSP在改善酸乳品质上明显优于HDSP和PMS.     

米邦塔仙人掌发酵乳饮料的工艺优化

以米邦塔仙人掌、脱脂乳粉为主要原料,发酵制备米邦塔仙人掌酸乳饮料.通过Box-Behnken响应面法优化发酵条件,其最佳工艺参数(以质量分数计)为:米邦塔仙人掌滤液添加量15.3％、蔗糖添加量9.4％、发酵剂(保加利亚乳杆菌:嗜热链球菌=1:1)接种量0.16％、发酵温度42℃条件下发酵6.8h,得到"米邦塔"仙人掌发酵乳饮料酸度为93.2°T,且风味独特、营养丰富.     

Effects of Three Strains Combinations of Lactobasillus buchneri,Aspergillus niger,Candida tropicalis,Bacillus subtilis and Lactobacillus plantarum on Fermentation Quality of Cassava Residue

The experiment was carried out to investigate effects of three strains combinations of Lactobasillus buchneri (LAB),Aspergillus niger (AN),Candida tropicalis (CT),Bacillus subtilis (BS) and Lactobacillus plantarum (LAP) on fermentation quality of cassava residue.In this study,cassava residue were used as fermentative raw material,three strains were combined by 1∶1∶1 chosen from LAB,AN,CT,BS and LAP,getting five different combination.Combination 1:LAB+AN+LAP;Combination 2:LAB+CT+LAP;Combination 3:LAB+BS+LAP;Combination 4:AN+CT+LAP;Combination 5:CT+BS+LAP;1% urea or 1% urea+0.6% brown sugar was added to each combination;Blank group was without any additives;1% urea was added to control group Ⅰ and 1% urea+0.6% brown sugar were added to control groupⅡ.Experimental group Ⅰ was consisted of control group Ⅰ+different combination (1-5) while experimental group Ⅱ was consisted of control group Ⅱ+different combination (1-5).Water content in each group was about 65% by modulating with normal saline,each group was fermented in the vacuum of polyethylene film bag for 10 days.The results showed as follows:①pH of each experimental group was significantly lower than that of blank group and control group (P < 0.05),experimental group Ⅱ1 (LAB+AN+LAP+urea+brown sugar) could improve acetic acid content of cassava residue and reduce the NDF and ADF contents,and which were the lowest and were significantly lower than that of blank group and the control groups (P < 0.05);②Experimental group Ⅱ5 (CT+BS+LAP+urea+brown sugar) could improve the crude protein content in the cassava residue which was significantly higher than that of blank group and the control groups (P < 0.05);③It was favorable to propionic acid production by adding the corresponding strains+urea+brown sugar to the cassava residue fermentation;④Urea and brown sugar were added into cassava residue for improving the nutrition composition during the fermentation process was better than that only urea was added;⑤When the urea was added into the fermentation medium,the crude protein content in cassava residue was significantly increased,when cassava residue fermented quality was evaluate by butyric acid and acetic acid contents,all the groups got to the top of grade.In conclusion,solid-state fermentation using LAB+AN+LAP+urea+brown sugar or CT+BS+LAP+urea+brown sugar could offer an effective alternative to improve the fermentation quality of cassava residue.     

固相萃取-高效液相色谱法测定乳制品中三氯蔗糖

建立乳制品中三氯蔗糖的固相萃取高效液相色谱检测方法.采用0.2％乙酸水溶液沉淀蛋白,提取三氯蔗糖,然后通过C18固相萃取柱进行净化浓缩后,采用高效液相色谱-蒸发光散射检测仪进行检测,该方法0.1～0.8g/L范围内以三氯蔗糖进样质量的对数和相应峰面积的对数做标准曲线,R2为0.9991,相关性良好,加标回收率在94％～102％之间,检出限为2.0mg/L(RSN=3).     

布氏乳杆菌、黑曲霉、热带假丝酵母、枯草芽孢杆菌与植物乳杆菌3菌组合对木薯渣发酵品质的影响

本试验旨在研究布氏乳杆菌（LAB）、黑曲霉（AN）、热带假丝酵母（CT）、枯草芽孢杆菌（BS）与植物乳杆菌（LAP） 3菌组合对木薯渣发酵品质的影响。以木薯渣为发酵原料,取LAB、AN、CT、BS与LAP中3种菌液以1∶1∶1体积比组合,共设5个不同组合：组合1：LAB+AN+LAP;组合2：LAB+CT+LAP;组合3：LAB+BS+LAP;组合4：AN+CT+LAP;组合5：CT+BS+LAP;空白组不添加任何添加剂,对照组Ⅰ添加1%尿素;对照组Ⅱ添加1%尿素+0.6%红糖,试验组Ⅰ为对照组Ⅰ+不同菌种组合（1~5）,试验组Ⅱ为对照组Ⅱ+不同菌种组合（1~5）。各组均用生理盐水调制含水量为65%左右,于聚乙烯薄膜袋中真空发酵10 d。结果显示：①各试验组的pH均显著低于空白组和对照组（P < 0.05）,试验Ⅱ1组（即LAB+AN+LAP+尿素+红糖）能提高木薯渣的乙酸含量,降解木薯渣中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）效果最好,其NDF和ADF含量均为最低,显著低于空白组和对照组（P < 0.05）;②试验Ⅱ5组（即CT+BS+LAP+尿素+红糖）提高木薯渣粗蛋白质（CP）含量效果最好,其CP含量最高,显著高于空白组和对照组（P < 0.05）;③添加相应的菌种+尿素+红糖发酵木薯渣有利于产生丙酸;④在木薯渣发酵过程中添加尿素+红糖比只添加尿素对木薯渣营养成分改善效果好;⑤在发酵培养基中添加尿素,能显著提高木薯渣CP含量;以乙酸和丁酸含量评价木薯渣品质,发现各组发酵木薯渣品质均达到1级水平。综上所述,LAB+AN+LAP+尿素+红糖或CT+BS+LAP+尿素+红糖固态发酵木薯渣后,均可有效改善木薯渣品质。     

高寒地区燕麦籽粒糖降解和淀粉积累动态分析

为探讨高寒地区燕麦花后籽粒中糖降解和淀粉积累特点,分析了2个品种花后籽粒中糖降解和淀粉积累动态。结果表明籽粒中淀粉均呈"S"型曲线增长,花后6~15d可溶性糖转化速率较高,淀粉积累速率较快,其后可溶性糖转化速率和淀粉积累速率较低,可溶性糖处于动态平衡中。     

采食不同来源淀粉对生长猪门静脉养分吸收和增重的影响

研究了不同来源淀粉对生长猪门静脉养分净吸收量和生产性能的影响。结果表明：玉米和糙米组成的试验日粮生长猪生长速度最快，显著快于糯米组（P〈0．05），极显著地快于抗性淀粉组（P〈0．01）。生长猪采食抗性淀粉日粮后，葡萄糖和总氮基酸的门静脉净吸收量分别仅为17．84g／100gFI和5．93g／100gFI，显著低于玉米、糙米和糯米组（P〈0．05）。门静脉净吸收氨基酸模式与回肠末端可消化氮基酸模式有很大区别，肠黏膜代谢对氨基酸模式有选择的修饰作用。生长猪增重速度与门静脉总必需氩基酸净吸收量有比较高的相关关系（P=0．0295）。     

高寒地区牧草碳水化合物及氨基酸含量季节动态研究

对高寒地区13种牧草碳水化合物(可溶性糖、淀粉)和氨基酸(总游离氨基酸、赖氨酸)含量进行研究.结果表明,球花蒿、高山龙胆、禾草、珠芽蓼和黄花棘豆5种牧草可溶性糖、淀粉、总游离氨基酸、赖氨酸含量随季节呈单峰曲线变化,其最高值和最低值分别出现在6或7月和12或1月;6月13种牧草可溶性糖和淀粉含量不同,变化幅度在0.55%～2.05%,7月8种牧草游离氨基酸和赖氨酸含量变化幅度分别在0.36%～1.37%和0.14%～1.11%;同一时期部分牧草草地来源不同,可溶性糖、淀粉、总游离氨基酸和赖氨酸含量差异显著,部分牧草则差异不显著;淀粉比可溶性糖、总游离氨基酸和赖氨酸更易受环境因子的影响,且它们之间并不一定成正相关性.     

陈化早籼糙米的适宜挤压膨化工艺参数研究

试验旨在研究实验室条件下的挤压膨化机螺杆转速、套筒温度、喂料速度、原料水分等工艺参数条件,对贮存3年的陈化早籼糙米淀粉糊化度和挤压膨胀度的影响,进而确定陈化早籼糙米的适宜挤压膨化加工参数。结果表明:当螺杆转速或喂料速度加快时降低了陈化早籼糙米淀粉糊化度和挤压膨胀度;适当提高套筒温度、保持适宜的原料水分可提高淀粉糊化度和挤压膨胀度,就评价陈化早籼糙米挤压膨化的效果而言,挤压膨胀度与淀粉糊化度的效应一致。实际生产时建议采用80～90℃膨化温度,20%原料水分,30.6kg/min喂料速度的膨化工艺参数。     

不同添加剂对紫花苜蓿拉伸膜裹包青贮饲料品质的影响

为明确葡萄糖、红糖、果渣对紫花苜蓿拉伸膜裹包青贮饲料青贮品质的影响,探明最适合添加于紫花苜蓿裹包青贮的有机添加剂,按照紫花苜蓿原料重量的0.2%、0.4%、10%分别添加葡萄糖、果糖、果渣进行90 d青贮。结果表明:添加葡萄糖可保留紫花苜蓿中更多的干物质,有效提高青贮饲料中的乳酸含量,降低乙酸和丙酸含量;添加红糖不利于青贮饲料pH值的降低和乳酸积累,能产生较高的氨态氮、乙酸和丙酸含量;添加果渣虽然可以降低青贮饲料的pH值,但会造成显著的粗蛋白损失。综合分析认为,添加葡萄糖对提高紫花苜蓿拉伸膜裹包青贮饲料青贮品质效果较好。     

Effects of Dietary Starch Source on Nutrient and Energy Absorption via the Portal Vein of Growing Pigs

Four crossbred(Duroc×Landrace×Yorkshire)boars,weighing an average of 22.40 ± 1.08 kg and fitted with permanent catheters in their portal and mesenteric veins as well as their carotid artery,were utilized in a 4 × 4 latin square design experiment in order to investigate the effects of different starch sources(maize,brown rice,sticky rice,and resistant starch)on the absorption of energy sources through the portal vein.Portal blood flow averaged 30.68,28.40,29.99,and 30.12 mL/min per kg BW for pigs fed the maize,brown rice,sticky rice,and resistant starch diets,respectively,and did not differ(P0.05)between treatments.The absorptions of glucose,plasma ammonia,and total amino acids were significantly lower(P0.05)in pigs fed the resistant starch diet than pigs fed the other starch sources.In contrast,significantly(P0.05)higher amounts of propionate and total volatile fatty acids were absorbed from the portal vein of pigs fed resistant starch than pigs fed diets based on maize,brown rice,or sticky rice.In addition,significantly(P0.05)more lactic acid was absorbed from the portal vein by pigs fed the sticky rice diet than pigs fed the other three diets.The energy absorbed from the portal vein in the form of glucose and amino-N as well as the total energy absorbed was significantly(P0.05)lower in pigs fed the resistant starch diet than pigs fed the other three starch sources.In contrast,the amount of energy absorbed in the form of volatile fatty acids was significantly(P0.05)higher in pigs fed resistance starch than pigs fed the other three starch sources.The total energy absorbed through the portal vein as a percentage of the gross energy and digestible energy consumed in pigs fed maize were 50.8% and 54.6%,respectively,which were significantly(P0.05)higher than the values in pigs fed resistant starch(41.5% and 46.6% respectively).The results indicate that energy is absorbed in different forms and with different utilization efficiencies in the digestive tract of pigs as a result of feeding different starch sources.Starch sources supplying most of their energy in the form of glucose had higher energy utilization efficiencies,while starch sources supplying most of their energy in the form of volatile fatty acids or lactic acid had lower energy utilization efficiencies.     

Effect of maize starch concentration in the diet on starch and cell wall digestion in the dairy cow

An in vivo experiment was performed to determine the effect of level of maize starch in the diet on digestion and site of digestion of organic matter, starch and neutral detergent fibre (NDF). In a repeated change‐over design experiment, three cows fitted with a rumen cannula and T‐piece cannulae in duodenum and ileum received a low‐starch (12% of ration dry matter) and a high‐starch (33% of ration dry matter) diet. Starch level was increased by exchanging dried sugar beet pulp by ground maize. After a 2‐week adaptation period, feed intake, rumen fermentation parameters (in vivo and in situ), intestinal flows, faecal excretion of organic matter, starch and NDF were estimated. When the high‐starch diet was fed, dry matter intake was higher (19.0 kg/day vs. 17.8 kg/day), and total tract digestibility of organic matter, starch and NDF was lower when the low‐starch diet was fed. Maize starch concentration had no significant effect on rumen pH and volatile fatty acid concentration nor on the site of digestion of organic matter and starch and rate of passage of ytterbium‐labelled forage. On the high‐starch diet, an extra 1.3 kg of maize starch was supplied at the duodenum in relation to the low‐starch diet, but only an extra 0.3 kg of starch was digested in the small intestine. Digestion of NDF was only apparent in the rumen and was lower on the high‐starch diet than on the low‐starch diet, mainly attributed to the reduction in sugar beet pulp in the high‐starch diet. It was concluded that without the correction for the reduction in NDF digestion in the rumen, the extra supply of glucogenic (glucose and propionic acid) and ketogenic nutrients (acetic and butyric acid) by supplemented starch will be overestimated. The mechanisms responsible for these effects need to be addressed in feed evaluation.