Endogenous nitrogen losses in rats fed by intravenous and enteral routes

Endogenous losses of nitrogen were studied under the feeding with isocaloric mixtures containing glucose, polycose, mineral substances, and vitamins. At the end of the first week endogenous losses of nitrogen with urine and feces under both routes of feeding were higher than at the end of the second week of nitrogen-free feeding. Upon intravenous feeding the nitrogen-saving action of the mixture containing glucose was more remarkable at the end of the second week than that of the mixture containing glucose and fatty emulsion. Endogenous losses of nitrogen upon intravenous feeding with a mixture containing fatty emulsion and glucose and losses upon intragastric feeding with a mixture of fatty emulsion and polycose were similar at the end of the second week.     

Enterochromaffin cells of the intestinal mucosa during long-term parenteral and intragastric feeding

The authors studied the response of enterochromaffin cells (Ec-cells) of the duodenal mucosa of rats during parenteral and intragastric administration of food mixtures containing a fatty emulsion venolipid (Japan) and of food mixtures containing no fat. The food mixture was administered round the clock, uniformly throughout 15 days. The Ec-cells were detected by the argentaffinity method modified by Phontane . It was discovered that during parenteral and intragastric administration of the food mixture containing a fatty emulsion, the amount of the Ec-cells in the duodenal mucosa was 3 times greater as compared with control. There were cells with varying intensity of the argentaffinity response, which attests to an active release of hormones synthesized by the Ec-cells. During intragastric administration of the food mixture containing no fatty emulsion, the status of the Ec-cells was the most similar to that seen in control. This is suggestive of an important role of the diet fat for changes in the Ec-cells. The changes found should be taken into consideration in the assessment of the effects of parenteral and intragastric feeding on the body and intestine and in the choice of the most optimal methods of feeding.     

Gastric secretory function and the energy component of the mixtures used in parenteral feeding

Experiments on dogs with a gastric fustula and Pavlov's (miniature) isolated pouch, kept on a high-standard mixed ration evidenced that intravenous administration of various substances acts on the fundal gastric glands differently. Some of such substances stimulate the secretion of an acid gastric juice (xylitol and ethyl alcohol), while others are inert in this respect (sorbitol, 1.2-propandiol, 1.3-butandiol, fatty intralipid emulsion). Five percent solutions of glucose and fructose do not provoke any significant secretion of juice, although also lead to a short-lived pH fall in the gastric secretion. At the same time the action of the said substances is markedly less intensive than the caseine hydrolysate (TSOLIPK) has an effect on the gastric juice. In the practice of parenteral nutrition with the preparation of nutrative mixtures the ability to provoke the gastric secretion by the ethyl alcohol and xylitol an account should be taken of.     

均质压力对亚麻籽油体乳液稳定性及体外消化的影响

本实验以亚麻籽油体为研究对象,通过对其进行均质处理,得到了稳定的富含α-亚麻酸的亚麻籽油体乳液,为居民在日常膳食中提高-3不饱和脂肪酸摄入量提供了新的途径。在保持均质时间相同的条件下(3 min),对亚麻籽油体进行不同均质压力(40、80、120 MPa)与均质次数(1～3次)处理,考察均质处理对亚麻籽油体乳液的性质、环境稳定性(pH、离子强度、热、氧化稳定性)、储藏稳定性和消化特性的影响。结果表明,FOB在120 MPa下均质处理3次,电位绝对值增加,粒径显著减小(P<0.05)。均质处理后的亚麻籽油体乳液在50～90℃下热处理30 min,粒径、电位稳定,且表现出更好的氧化稳定性和储藏稳定性(P<0.05)。均质处理亚麻籽油体并不影响其对pH4～5和离子强度不稳定(P>0.05)。消化结果表明,均质处理后的亚麻籽油体乳液具有更快的脂肪酸释放速率(FFA)。综上,均质处理显著了减小亚麻籽油体乳液的粒径,增强了亚麻籽油体的储藏稳定性和氧化稳定性,且加快了脂肪酸释放速率。     

Characterisation of gelatin–fatty acid emulsion films based on blue shark (Prionace glauca) skin gelatin

Incorporation of fatty acids (stearic and oleic) into edible films based on blue shark (Prionace glauca) skin gelatin was investigated to modify properties such as water vapour barrier and flexibility due to their hydrophobicity and plasticizing effect, respectively. Addition of stearic acid from 0% to 100% of protein concentration in the film-forming solution considerably decreased water vapour permeability of gelatin–fatty acid emulsion films compared to addition of oleic acid at the same fatty acid concentration. Increasing concentrations of both fatty acids decreased tensile strength, but increased elongation at break due to their plasticizing effect. At the same concentration, oleic acid gave a greater plasticizing effect than did stearic acid. On the other hand, transparency of the gelatin–stearic acid emulsion film was lower than that of the gelatin–oleic acid emulsion film. Faster stirring speed of homogenisation improved properties of only the gelatin–stearic acid emulsion film.     

Infrared spectroscopy of the skin: influencing the stratum corneum with cosmetic products

The stratum corneum is the outermost layer of the skin and, as such, represents the decisive barrier between the body and the environment. The combination of horny cells and lamellar lipid layers prevents water loss from the body and protects it against penetration by exogenous substances. For selective investigation of the thin outermost stratum corneum layer ATR-FTIR (attenuated total reflection Fourier transform infrared) spectroscopy has proved itself in practice. It provides information about the sebum content, type of fatty substances, water content and degree of order of the lamellar lipid film in the stratum corneum. Different types of skin (dry, normal and greasy) differ mainly in their sebum content but also in the composition of their fats and the degree of order of their lipids. A comparison with model lipid mixtures shows that the stratum corneum lipids are mainly present in a fixed gel form under physiological conditions. In cleansing processes a large part of the sebum is removed from the skin. The skin reacts to the defatting process by the rapid secretion of sebum. After cleansing with a mild face cleansing emulsion the re-achievement of the same fat status takes longer than with a surfactant shower gel. Skin creams cause alterations to the skin moisture and in the degree of order of the stratum corneum lipids. A lamellar cream with a structure similar to that of the stratum corneum lipids increases the degree of order of the alkyl chains of the skin lipid film (biomimetic principle), whereas a conventional w/o cream reduces this degree of order. Skin moisture increases after the use of the creams.     

Fat assimilation and indicators of lipid metabolism in the blood of premature infants fed milk mixtures with different fat composition

The efficacy and adequacy of fat component depending on the feeding type (breast milk, Malyutka, Malyutka with a new fatty composition and Similak mixtures) were defined in the course of feeding 90 premature infants aged 33 to 37 weeks on the basis of clinical observations, determination of fat assimilation and the main indicators of lipid metabolism. All the mixtures were shown to be tolerated well. No significant differences were revealed in the mean daily weight gain and in the monthly body length gain. The children fed breast milk showed a higher assimilation of fats and an increase in the cholesterol level in the blood serum. The indicators of fat retention in children fed Similak and Malyutka with a new fatty composition mixtures were similar to those in children on natural feeding. The milk mixtures under consideration are found to be effective enough and thus can be used for feeding premature children born to mothers with hypo- and agalactia.     

Effect of a fat emulsion on the free amino acid content in the blood when administered enterally together with amino acids

The influence of an intralipid fatty emulsion on the absorbability of polyamine amino acid mixtures was studied during their administration through a tube into the duodenum of white rats. Polyamine was administered in a dose of 0.25 g of nominal protein, intralipid in a dose of 0.2 g of fat/g bw/day. It was found that polyamine administered into the small intestine was intensely absorbed during the first two hours which was evidence by an increased content of amino acids in the blood. Intralipid used simultaneously with polyamine intensified the absorption of the latter. Preliminary administration of intralipid promoted a more rapid polyamine absorption, especially of side branch chain amino acids. The results obtained have presented an experimental validation of using nitrous compounds after preliminary administration of fatty emulsions in enteral tube feeding.     

不同乳化剂对油酸和亚油酸乳状液稳定性的影响

本文以粒径、稳定性和流变为考察指标,利用激光粒度仪、食品稳定性分析仪、流变仪等研究不同种类和添加量的食品乳化剂(阿拉伯胶、酪蛋白酸钠、吐温20)对不饱和脂肪酸(油酸和亚油酸)乳状液的制备及其稳定性的影响。结果表明,三种乳化剂均可制备出稳定性较好的乳状液,不同乳化剂的质量分数不同得到乳状液的稳定性不同。较高质量分数的阿拉伯胶(4%,w/v)乳状液,具有最低的澄清指数并且具有最大粘度(0.30~0.40 Pa·s)。当酪蛋白酸钠的质量分数为2%时,制备出的乳状液较稳定,但粒径较大,贮藏稳定性较差。较低质量分数的吐温20(1%,w/v)的乳状液具有最小粒径(0.20~0.21 μm),经过贮藏后变化程度也最小。本文研究了不同食品乳化剂制备的不饱和脂肪酸乳状液及其稳定性,可为不饱和脂肪酸乳状液的制备和应用提供参考。     

亚麻籽胶对米糠油体稳定性及消化的影响

米糠油体作为天然水包油乳状液,在食品工业中具有良好的应用前景。为了进一步提高米糠油体的稳定性,本研究制备了亚麻籽胶稳定的米糠油体,探究亚麻籽胶质量分数对米糠油体稳定性及消化的影响。结果表明：亚麻籽胶质量分数为0.5%时,米糠油体平均粒径最小,zeta-电位绝对值最大,表观黏度增加,稳定性最好。体外模拟消化实验表明,米糠油体脂肪酸释放率为95%,亚麻籽胶的添加减缓了米糠油体脂肪酸的释放(89%),可以起到缓释脂肪酸的效果。本研究对于提高油体稳定性及拓宽米糠油体作为功能因子递送载体在食品加工中的应用有重要意义。     

Effects of intravenous triacylglycerol emulsions on hepatic metabolism and blood metabolites in fasted dairy cows

The objective was to determine the effects of intravenous infusion of triacylglycerol (TAG) emulsions derived from different lipid sources on energy metabolism during a 4-d fast. Six nonpregnant, nonlactating multiparous Holstein cows were randomly assigned to treatments in a replicated 3 x 3 Latin Square design. Treatments included intravenous infusion of tallow, linseed oil, or fish oil emulsions at a rate of 0.54 g of TAG/kg of body weight per day; infusions were concurrent with a 4-d fast. The emulsions were administered for 20 to 30 min every 4 h throughout the 4-d fast. Cows were fed ad libitum for 24 d between the fast/infusion periods. Infusion of tallow, linseed oil, or fish oil emulsions increased plasma concentrations of palmitic acid, linolenic acid, and eicosapentaenoic and docosahexaenoic acids, respectively. Infusion of linseed oil emulsion decreased plasma TAG concentrations compared with tallow and fish oil treatments, which were similar. Infusion of the tallow emulsion resulted in the highest concentrations of plasma nonesterified fatty acid (NEFA), insulin, and glucose, whereas the infusion derived from linseed oil had the lowest NEFA and beta-hydroxybutyric acid concentrations. The different TAG emulsions had no effect on total or peroxisomal oxidation of [1-(14C)]oleic acid in liver homogenates. Liver TAG content increased 12.0, 7.8, and 14.1 microg/microg of DNA during the fast for tallow, linseed oil, and fish oil treatments, respectively; linseed oil was different from fish oil and tended to be different from tallow.     

再生纤维素-乳清分离蛋白乳化液对乳化肠品质的影响

利用再生纤维素（regenerated cellulose,RC）-乳清分离蛋白（whey protein isolate,WPI）乳化液替代乳化肠中0%、33%、66%和100%的猪背膘,研究RC乳化液对乳化肠化学组成、颜色、蒸煮损失、质构、脂肪酸组成、脂肪氧化以及肉糜动态储存模量（G’）的影响。结果表明：随着RC-WPI乳化液含量的增加,乳化肠中脂肪含量和脂肪氧化程度显著降低（P＜0.05）,亮度值显著提高（P＜0.05）;与对照组（C）相比,替代66%（T2）组蒸煮损失显著降低（P＜0.05）;添加乳化液肉糜的动态G’高于对照组,替代33%（T1）和66%（T2）的猪背膘时,乳化肠的硬度、弹性和咀嚼性显著高于对照组（P＜0.05）;随着替代比例的增加单不饱和脂肪酸含量显著提高,饱和脂肪酸含量显著降低（P＜0.05）。结果表明,RC-WPI橄榄油乳化液替代66%猪背膘时,可以提高乳化肠品质并且改善脂肪酸组成。     

Bitter taste of unsaturated free fatty acids in emulsions: contribution to the off-flavour of soybean lecithins

The contribution of (poly-) unsaturated free fatty acids (FFAs) to the bitterness of soybean lecithins was investigated by an analytical-chemical and by a sensory approach. Standardized, hydrolyzed, deoiled, and fractionated soybean lecithins were characterized by taste profiles and their yields of FFA were quantified. Threshold tests revealed the polyunsaturated free linoleic acid (cis-9, cis-12-octadecadienoic acid) and free linolenic acid (cis-9, cis-12, cis-15-octadecatrienoic acid) as the FFAs with the lowest bitter taste thresholds in emulsion and the highest impact on the off-taste problems of soybean lecithins and their applications. These results were confirmed by sensory model mixtures. Furthermore, the relationship between FFAs and the perceived bitterness in dependency on the emulsion and the intensity of FFA bitterness in correlation to the FFA concentration were investigated.     

Potential for using a protein-based enteral feeding formula as nutrient mixtures in transintestinal nutrition

Chronic experiments on semi-fistula dogs with temporal-isolated parts of the small bowel were made to study the rate of nitrogen, glucose, lipid, sodium, potassium, calcium and water absorption from protein enteral nutrition and nutritive mixtures prepared on its basis. It was established that a nutritive mixture based on 10% protein enteral nutrition with additives in the form of fatty emulsion and sodium chloride was quite suitable for transintestinal administration. The increase of the concentration of protein enteral nutrition administered transintestinally or its preliminary hydrolysis by gastric juice resulted in the enhancement of evacuatory function of the small bowel.     

不饱和脂肪酸对猪肉蛋白质乳化特性的影响

研究不同饱和程度且不同添加量的脂肪酸对全肉盐溶性蛋白乳化特性、流变特性以及Zeta电位等影响。结果显示：脂肪酸添加量越大,乳化液的乳化活性越强,而乳化液的分层现象越严重;添加油酸和亚油酸可以明显增加乳化液的表面活性巯基;各乳化液粒度分布曲线均呈现“单峰”型,且较空白组的分布均向粒径较小的范围偏移;此外,随着剪切速率的增大,各乳化液黏度均逐渐减小,最后趋于平缓,在同一剪切速率下,添加量越大,乳化液剪切应力越大;Zeta电位值显示,荷电粒子不稳定。总之,C18的脂肪酸饱和程度越大,添加量越多,猪肉盐溶性蛋白质乳化的效果越好,在脂肪酸液滴表面形成蛋白膜的能力就会越强,使得乳化液的乳化特性越好。     

基于天然大豆油脂体-海藻酸钠的沙拉汁工艺研究

以天然大豆油脂体替代传统沙拉汁中的油脂,并利用多糖海藻酸钠(ALG)作为稳定剂制备新型沙拉汁。结果表明,通过带负电ALG与带正电油脂体的静电相互作用,提高了天然大豆油脂体在弱酸性条件下的分散性和稳定性,0.35%的ALG可在pH4.5下很好地稳定1.0%油脂体乳液。通过体外模拟小肠内油脂消化过程,发现天然大豆油脂体乳液比吐温80-大豆油乳液的游离脂肪酸释放量低10%左右,且ALG进一步延缓了大豆油脂体初期消化速度。高浓度的ALG(0.5%、0.6%、0.8%、1.0%)可分别提高高浓度油脂体乳液(10.0%、20.0%、30.0%、40.0%)的稳定性。以市售沙拉汁为对照,优化了沙拉汁配方中大豆油脂体与ALG的用量,将质量分数为60.0%的大豆油脂体-ALG的乳液(含40.0%油脂体和1.0% ALG)用于沙拉汁配方中,得到粘度与市售配方匹配,稳定性更佳的沙拉汁。新型沙拉汁配方综合了大豆油脂体和海藻酸钠的双重优点,具有含油量低、脂肪消化慢、营养素天然健康,且储存稳定的特点。     

Optimization of emulsion characteristics of beef, chicken and turkey meat mixtures in model system using mixture design

Emulsion pH (pHe), emulsion capacity (EC), emulsion stability (ES), emulsion density (ED) and apparent yield stress of emulsion (raw emulsion, AYSe) and emulsion gel (cooked emulsion, AYSg) of beef, chicken and turkey meats and their mixtures were studied using a model system.

Turkey meat homogenate was found to have higher protein concentration than chicken or beef homogenates. The highest pHe, EC and ES values and the lowest ED and AYSe values were found in chicken meat. However, the highest AYSg value was found in chicken–turkey meat mixture. Generally, the increasing amount of chicken meat in mixtures increased EC and ES, and decreased ED and AYSe values. Also, chicken–turkey meat mixtures had lower ES values than the mixtures containing only chicken or only turkey meat. With beef, the addition of chicken and turkey meats improved emulsion characteristics significantly. Optimum levels of beef, chicken and turkey meats were found to be 0–23%, 9–30% and 53–91% respectively.     

乳液体系包埋亚麻籽油研究进展

亚麻籽油富含多不饱和脂肪酸,具有多种生物活性功能,同时,亚麻籽油亦存在氧化稳定性差、水溶性低、生物利用度低等缺陷,严重限制了其在食品及其它领域的应用。利用乳液体系包埋亚麻籽油是解决这些缺陷的一种潜力方法。本文归纳总结了普通乳液、微乳液、纳米乳液、Pickering乳液、多层乳液以及乳液凝胶等不同乳液体系的特点及其包埋亚麻籽油的研究现状,分析了不同乳液体系提高亚麻籽油氧化稳定性和生物利用度的原因,对乳液体系包埋后亚麻籽油的应用现状进行综述,旨在为乳液体系的深入研究以及亚麻籽油的广泛应用提供一定理论参考。     

Effect of cooking on the chemical composition of low-salt, low-fat Wakame/olive oil added beef patties with special reference to fatty acid content

Changes in chemical composition, with special reference to fatty acids, as affected by cooking, were studied in low-salt (0.5%)/low-fat patties (10%) with added Wakame (3%) and partial or total replacement of pork backfat with olive oil-in-water emulsion. The addition of Wakame and olive oil-in-water emulsion improved (P < 0.05) the binding properties and the cooking retention values of moisture, fat, fatty acids and ash, which were close to 100%. Partial and total replacement of animal fat with olive oil-in-water emulsion reduced (P < 0.05) saturated fatty acids (SFAs), while total replacement also reduced (P < 0.05) polyunsaturated fatty acid (PUFAs) contents. The fatty acid concentration in cooked patties was affected by product formulation. Unlike the case of all animal fat patties, when olive oil was added the cooking process increased (P < 0.05) SFAs, monounsaturated fatty acids (MUFAs) and PUFA n-3 (linolenic acid) and n-6 (linoleic acid) contents. Cooked formulated patties with seaweed and partial or total replacement of pork backfat by oil-in-water emulsion and with seaweed added were less calorie-dense and had lower SFAs levels, while samples with olive oil had higher MUFAs levels.     

Tailoring fatty food simulants made from solvent mixtures (2): determining the equivalent migration behaviour of olive oil and of solvents in the case of polyolefins

It is suggested that solvent mixtures consisting of an ester and of an inert solvent can be used as fatty food simulants capable of having the same migration behaviour as olive oil with plastics. Migration tests carried out with low-density polyethylene for 20 and 48h in an 8 and 5% mixture of tert-butyl acetate in ethanol respectively gave results equivalent to those obtained with olive oil after 10 days at 40°C. The use of solvent mixtures facilitated the analysis and improved detection limits, giving good repeatability. Furthermore, the more rapid migration in solvent mixtures can be particularly useful for industrial controls as alternative test methods.