鱼油风味酸奶的开发及稳定性评价

以全脂奶粉、鱼油、白砂糖为主要原料,以保加利亚乳杆菌和嗜热链球菌为发酵菌种制作鱼油风味酸奶,进行鱼油风味酸奶配方研究与产品稳定性评价。通过感官评定确定最佳酸奶配方为奶粉添加量10%,鱼油添加量0.15%,白砂糖添加量8%。核磁共振与显微观察结果表明,鱼油添加后未对酸奶水分分布产生影响,鱼油在酸奶中呈均匀分布。电子鼻分析结果表明,与原味酸奶相比,鱼油风味酸奶风味更为融合,更接近原味商业酸奶。以储存期pH、酸度、流变特性、感官评价为指标对鱼油风味酸奶进行了稳定性评价,结果表明鱼油风味酸奶在储存期内可保持良好的稳定性,鱼油的添加可有效避免酸奶的过度酸化,使酸奶保持良好的口感。     

螺旋藻营养保健酸奶的研制

通过向纯鲜牛乳中添加螺旋藻制剂,经乳酸菌发酵,制得一种浅绿色、风味独特的全营养新型酸奶。研究了螺旋藻酸奶的加工工艺及配方、产品感官性状、酸度和发酵菌数量等变化。通过四因素三水平正交试验确定各种成分的最佳剂量,确定产品配方为:合格鲜牛乳,白砂糖8%,羧甲基纤维素0.2%,发酵剂接种量5%(均为质量分数,下同),螺旋藻提取液10%。     

双蛋白奶的研制及理化指标检测

以燕麦粉和鲜牛乳为主要原料,7%的木糖醇为甜味剂,研制了一种保健型酸奶-凝固型燕麦发酵酸奶。以产品感官质量和稳定性为评价指标,应用正交试验设计,确定了合理的配方和适宜发酵的工艺。结果表明：燕麦酸奶主要原料的最佳配方为：燕麦添加量1.5%、发酵剂接种量5%、发酵温度42℃、发酵时间4h。     

龙桑果风味酸乳发酵工艺的研究

将龙桑果汁与牛奶调配混合,经乳酸菌发酵,制成凝固型龙桑果风味酸奶,通过预先筛选和进一步正交试验确定龙桑果风味酸奶的最佳发酵工艺及配方。结果表明,采用脱脂鲜牛乳为基料,添加20%桑果汁、8%蔗糖、接种3.0%保加利亚乳杆菌和嗜热链球菌(11∶),42℃发酵3h,所得产品为紫色,凝乳较结实、口感细腻,有酸奶和龙桑果的复合香味,风味独特。     

番木瓜酸奶加工工艺的研究

番木瓜酸奶是以鲜牛乳为原料,经杀菌、冷却后进行乳酸发酵,再加入以番木瓜为原料提取的木瓜浆、蔗糖、稳定剂等调制而成的产品。本文探讨了番木瓜酸奶的加工工艺及操作条件,并通过正交实验确定了产品的配方。     

混合果肉酸奶的研制

在酸奶技术的基础上,将猕猴桃与鲜牛乳的混合液接入乳酸菌发酵。采用单因素实验设计和正交实验设计,用保加利亚乳杆菌和嗜热链球菌混合发酵猕猴桃牛乳混合液,以乳清析出率、酸度和感官质量评定为依据,筛选出产品的最佳配方工艺条件为鲜牛乳81.7%、猕猴桃8%、另加蜂蜜量4%、稳定剂0.32%、发酵接种量3.0%、41℃下发酵6h,而后添加3%的葡萄干、0～4℃下后熟12h。该果肉酸奶的感官评定值可达91～95。     

甘薯南瓜酸奶的工艺研究

以甘薯和南瓜的原浆及鲜乳为乳酸菌的发酵基质,经加工处理、调配后进行乳酸发酵,通过正交试验确定酸奶的最佳配方和发酵的最适工艺参数,制成一种营养丰富、风味独特并具有保健功效的甘薯南瓜酸奶.结果表明:该酸奶乳的最佳配方为牛乳用量为75%,甘薯浆与南瓜浆的体积比2:1,糖用量5%;最佳发酵工艺参数为前发酵温度为40℃,前发酵时间为7h,接种量为5%.     

甘草酸奶的研制

以牛乳和甘草汁为主要原料,用嗜酸乳杆菌、保加利亚乳杆菌和嗜热链球菌(1∶1∶4)为发酵剂,从产品感官质量和滴定酸度入手,采用正交实验探讨甘草酸奶的配方和生产工艺.结果表明,甘草酸奶的最佳配方为:牛乳77%、甘草汁15%、蔗糖6.5%,乳粉1.5%,胶之素0.2%;最佳加工工艺为:发酵温度40℃,发酵时间6h,接种量4%.     

果味活菌乳酸饮料的研制

以新鲜牛乳为原料,在发酵酸奶的基础上,加入稳定剂、蜂蜜、香精、糖类等,通过正交实验,确定了最佳工艺配方、技术参数和产品的质量指标,得到一种营养、风味独特的果味活菌乳酸饮料。     

凝固型北冬虫夏草酸奶的研制

以鲜牛乳为主要原料,添加北冬虫夏草液体发酵混合液及蔗糖等辅料,经保加利亚乳杆菌和嗜热链球菌混合液接种发酵,生产出凝固型酸奶。着重对北冬虫夏草发酵混合液的添加量、蔗糖的添加量、稳定剂的选择、发酵条件优化,以及发酵终点的确定进行了研究。结果表明,当蔗糖的添加量为8%、保加利亚乳杆菌和嗜热链球菌以1∶1的比例混合接种量为3%时,北冬虫夏草酸奶生产的最佳配方及发酵条件是：牛乳70%、北冬虫夏草发酵液30%、琼脂0.3%、发酵温度40℃、时间3.5h左右,可获凝固性良好、酸甜适口,并具有浓郁香味的北冬虫夏草酸奶。     

Influence of dietary fish oil on conjugated linoleic acid and other fatty acids in milk fat from lactating dairy cows

Lactating cows were fed menhaden fish oil to elevate concentrations of conjugated linoleic acid, transvaccenic acid, and n-3 fatty acids in milk. Twelve multiparous Holstein cows at 48+/-11 DIM were assigned randomly to a replicated 4 x 4 Latin square. Each treatment period was 35 d in length, with data collected d 15 to 35 of each period. On a dry matter (DM) basis, diets contained 25% corn silage, 25% alfalfa hay, and 50% of the respective concentrate mix. Fish oil was supplemented at 0, 1, 2, and 3% of ration DM. Linear decreases were observed for DM intake (28.8, 28.5, 23.4, and 20.4 kg/d) and milk fat (2.99, 2.79, 2.37, and 2.30%) for 0 to 3% dietary fish oil, respectively. Milk yield (31.7, 34.2, 32.3, and 27.4 kg/d) increased as dietary fish oil increased from 0 to 1% but decreased linearly from 1 to 3% dietary fish oil. Milk protein percentages (3.17, 3.19, 3.21, and 3.17) were similar for all treatments. When the 2% fish oil diet was fed, concentrations of conjugated linoleic acid and transvaccenic acid in milk fat increased to 356% (to 2.2 g/ 100 g of total fatty acids) and 502% (to 6.1 g/100 g), respectively, of amounts when 0% fish oil was fed. There were no additional increases in these fatty acids when cows were fed 3% fish oil. The n-3 fatty acids increased from a trace to over 1 g/100 g of milk fatty acids, when the 3% fish oil diet was fed. Fish oil supplementation to diets of dairy cows increased the conjugated linoleic acid, transvaccenic acid, and n-3 fatty acids in milk.     

Addition of protected and unprotected fish oil to diets for dairy cows. I. Effects on the yield,composition and taste of milk

Thirty Holstein cows in mid-lactation (158+/-20 DIM) were given a total mixed ration based on grass silage, maize silage and rolled barley. After a preliminary period of 1 week, this diet was supplemented with nothing (control), unprotected fish oil (3.7% of dry matter, DM), or two levels of glutaraldehyde-protected microcapsules of fish oil (1.5% and 3.0% of DM, respectively). Unprotected and protected supplements contained, respectively, 74% and 58% of DM as lipids. Cows given the unprotected supplement reduced their feed intake by > 25%. Consequently, these cows lost body weight and produced less milk. DM intake, body weight, and milk yield were unaffected by protected fish oil. Fish oil reduced both milk fat and protein percentages, and decreased the proportion of short-chain fatty acids, stearic, and oleic acids in milk fat. Milk trans C18:1 fatty acids increased in cows given both unprotected and protected fish oil. Milk fat content of very-long-chain n3 polyunsaturated fatty acids, including C20:5 and C22:6, increased with fish oil in the diet. Accordingly, the peroxide index increased and a taste panel was able to detect unusual taste in milk from cows consuming the higher level of protected fish oil and disliked the milk from cows given unprotected fish oil. In conclusion, when lactating cows consumed fish oil, milk concentration of long-chain n3 fatty acids increased and mammary de novo synthesis of fatty acids decreased, but milk yield and milk protein content were reduced, and the milk was more susceptible to oxidation and its taste was adversely affected.     

DHA藻油的生理功能及在食品中复配协同应用的研究进展

二十二碳六烯酸（docosahexaenoic,DHA）是一种人体必需的多不饱和脂肪酸,属于omega-3家族,主要来源为鱼油和藻油。与鱼油相比,藻油因为含有较高的DHA纯度和更高的安全性而备受青睐,因此被大量应用在食品和保健品中,与食品中的成分相互影响、协同增效。本文综述了DHA藻油的生理功能,包括促进大脑和眼部神经发育、增强免疫力、抗氧化和抗癌等。总结了DHA藻油在牛奶、酸奶、奶粉中的应用,探讨了它与益生菌、益生元、磷脂酰丝氨酸、卵磷脂等食品成分相互作用的效果与机制,为食品、保健品行业更广泛、深入地使用DHA藻油提供理论依据。     

离子阱质谱测定脂质鉴别深海鱼油

建立基于高效液相色谱-离子阱质谱脂质识别技术,用于鉴别合成乙酯型和天然甘油酯型深海鱼油。使用反相液相色谱,C18色谱柱,异丙醇和乙腈梯度洗脱分离脂质。使用离子阱质谱数据依赖型二级扫描获得脂质多级碎裂指纹信息。通过总离子流、一级质谱、二级质谱离子树识别脂质指纹信息。识别获知二十二碳六烯酸（docose hexaenoie acid,DHA）和二十碳五烯酸（eicosapentaenoic acid,EPA）在乙酯型深海鱼油中存在方式为CH3CH2O-DHA和CH3CH2O-EPA,而在天然甘油酯型深海鱼油的存在方式为甘油三酯指纹信息。此方法能准确区分乙酯型深海鱼油和甘油酯型深海鱼油。     

人乳替代脂鲳鱼油和巴沙鱼油的脂肪酸、甘油三酯 组成及含量分析

为寻找与中国人乳脂脂质组成高相似的天然人乳替代脂，分析比较了3种鱼油(金鲳鱼油、银鲳鱼油和巴沙鱼油)的总脂肪酸、sn-2位脂肪酸、甘油三酯组成和含量。结果表明：金鲳鱼油中棕榈酸、油酸和亚油酸含量分别为24.93%、25.61%和26.52%,其中sn-2位棕榈酸的含量为39.71%,占总棕榈酸比例为53.10%;在3种鱼油中，金鲳鱼油总脂肪酸组成最接近中国人乳脂；甘油三酯组成分析结果证实，金鲳鱼油中富含1-油酸-2-棕榈酸-3-亚油酸甘油三酯(OPL,24.36%),其含量显著高于其他两种鱼油，且其1,3-二油酸-2-棕榈酸甘油三酯(OPO)的含量(16.79%)接近报道的中国人乳脂的平均含量(15.84%)。因此，金鲳鱼油是理想的中国婴儿配方奶粉专用油脂基料油，在人乳替代脂中具有良好的发展前景。     

Feeding fish meal and extruded soybeans enhances the conjugated linoleic acid (CLA) content of milk

Twelve multiparous Holstein cows averaging 65 (33 to 122) DIM were used in a 4 x 4 Latin square for 4-wk periods to determine whether feeding fish oil as fish meal would stimulate increased amounts of milk conjugated linoleic acid (cis-9, trans-11 C18:2; CLA) and transvaccenic acid (trans-11 C18:1; TVA) when the cows were fed extruded soybeans to supply additional linoleic acid. Treatment diets were 1) control; 2) 0.5% fish oil from fish meal; 3) 2.5% soybean oil from extruded soybeans; and 4) 0.5% fish oil from fish meal and 2% soybean oil from extruded soybeans. Diets were formulated to contain 18% crude protein and were composed (dry basis) of 50% concentrate mix, 25% corn silage, and 25% alfalfa hay. Intake of DM was not affected by diet. Milk production was increased by diets 2, 3, and 4 compared with diet 1 (control). Milk fat and milk protein percentages decreased with diets 3 and 4. Milk fat yield was not affected by treatments, but yield of milk protein was increased with supplemental fish meal and extruded soybeans or their blend. When diets 2, 3, or 4 were fed, concentrations of cis-9, trans-11 CLA in milk fat increased by 0.4-, 1.4-, and 3.2-fold, and TVA concentrations in milk fat increased by 0.4-, 1.8-, and 3.5-fold compared with the control milk fat. Increases in TVA and cis-9, trans-11 CLA were 91 to 109% greater when a blend of fish meal and extruded soybeans was fed than the additive effect of fish meal and extruded soybeans. This suggested that fish oil increased the production of CLA and TVA from other dietary sources of linoleic acid such as extruded soybeans.     

Sensory stability and oxidation of fish oil enriched milk is affected by milk storage temperature and oil quality

The experiments evaluated the influence of fish oil quality and cold storage temperature on the oxidative stability of milk emulsions containing 1.0% w/w milk fat and 0.5% w/w of either a pure fish oil or a fish oil:rapeseed oil mixture. The results showed that it was possible to produce a pasteurised milk product enriched with the important n-3 PUFA from fish oil with acceptable sensory characteristics if (1) the emulsions were based on a mixture of fish oil and rapeseed oil and (2) the initial peroxide value (PV) of the added oil blend was below 0.5 meq kg⁻¹. The sensory analysis showed a clear distinction between emulsions based on oil with PV 0.1 and 0.5 meq kg⁻¹, whereas the PV and the gas chromatographic (GC) analysis of volatile oxidation products were not sensitive enough to reveal these differences clearly. The GC analyses showed that the onset of formation of the volatiles was earlier with increased storage temperature in the range of 2–9 °C.     

Advances in dietary enrichment with n-3 fatty acids

Evidence for the effectiveness of the enrichment of food products with n-3 fatty acids by inclusion of either plant- or fish-derived materials in the diets of chickens, turkeys, ostriches, cows, pigs, and goats has been reviewed. Both linseed oil/meal and fish products can increase the levels of total n-3 fatty acids in animal products, including milk, eggs, meat, and deli products. The extent of this increase in n-3 fatty acid contents seems to be dependent on the nature of diet supplementation. Encapsulation of linseed oil may result in higher milk cow ALA contents, as compared to unprotected linseed oil. Available literature indicates that the levels of EPA and DHA in food products may be increased more, if the animals' diet was supplemented with fish products rather than linseed products. However, organoleptic properties of food products may be compromised. This pitfall may be reduced by the addition of antioxidants and/or application of micro-encapsulation. Generation of transgenic animals and plants has shown very promising results. Thus far, transgenic pigs and mice have been successfully generated. These animals have a low ratio of n-6:n-3 fatty acids in their tissues and milk. The advantages and disadvantages of the above-mentioned methods have been discussed. The evidence for health-promoting effects of such enriched food products has been included.     

南极磷虾油改善大鼠学习记忆能力研究

目的：观察南极磷虾油对Wistar大鼠学习记忆能力的影响。方法：采用Morris水迷宫法及Y-型迷宫刺激法观察,比较南极磷虾油和深海鱼油对大鼠学习记忆能力的作用。结果：Morris水迷宫实验显示南极磷虾油能够显著减少大鼠寻找平台潜伏期时间并且增加垮台次数和目标区域游泳时间所占比例(P＜0.05或P＜0.01);Y-型迷宫刺激实验表明南极磷虾油能够显著减少大鼠达标所需次数,显著提高48h后的实验正确率(P＜0.05或P＜0.01)。结论：南极磷虾油可显著改善大鼠学习记忆能力,且效果优于深海鱼油。     

Evaluation of processed cheese fortified with fish oil emulsion

Processed cheese fortified with fish oil is an excellent food for the delivery of omega-3 long-chain polyunsaturated fatty acids (omega-3 LC PUFA). However, oxidation and the “fishy” flavour of fish oil limit the level of fortification. The physical properties, lipid oxidation, and sensory perception of model processed cheese slices fortified with a fish oil emulsion (encapsulated fish oil) were examined and were compared with those of samples fortified with straight fish oil. Peroxide values, the results of thiobarbituric acid reactive substances (TBARS) tests, and propanal values showed that cheese samples fortified with fish oil emulsion had lower levels of oxidation than cheese samples fortified with non-encapsulated fish oil. A sensory panel detected a “fishy” flavour at a higher level of fish oil addition in the samples fortified with fish oil emulsion. This suggests that a fish oil emulsion made with a milk protein complex is a useful carrier for elevating the fortification level of omega-3 LC PUFA in processed cheese products.