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1.
Effects of Feed Fats on Quality of Animal Product At the same level of energy supply intake of fats/oils do not lead to a higher fat deposition in the carcass. Additionally, fats are carrier of fat soluble vitamins A, D, E, K and improve their absorption from the intestinal tract. The fatty acid profile of fat deposited in the organism, as for example in egg yolk is influenced by the intake of fatty acids provided by feed. This especially concerns linoleic- and linolenic acid as well as lauric- and myristic acid, High contents of polyunsaturated fatty acids negatively influence oxidative stability as well as consistency of body fat and therefore quality of animal products. An improved oxidation protection can be carried out by supplementation of antioxidants. Medium-chain, saturated fatty acids reveal positive effects on both criteria.  相似文献   

2.
Use of Feed Fats for Animal Nutrition and their Influence on the Quality of the Slaughtered Bodies For about 40 years fats have become an important feed component in rations of agricultural working animals. An increase of fat use in compound feed up to forty times was noted in the period from 1955 to 1984. But still today there are signs of uncertainty concerning quality assessment and selection of fats for feeding the various working animals. Today the quality of feed fats can be determined by analysis methods which enable a relatively quick assessment. Unfortunately there is no official control so that at last the compound feed factories have to fulfil this task. As fats have in comparison to carbohydrates an energy value which is 2.3 times higher, the energy amount of the compound feed increases by their addition. Thus the improved genetic ability of putting on weight of the working animals can completely be made use of. A greater fattiness of slaughtered bodies is not caused by fat addition in balanced rations. Because of their variety of different fatty acids and above all by their differences in the consistency and oxidation stability fats are of great influence on the performance of the animals and their slaughtered body quality. Depending on the content of polyenic acids and their oxidation degree lower increases of weight and damages in the organism are possible. High amounts of multiple unsaturated fatty acids cause a worse fat consistency in the slaughtered body and the from that produced products. Furthermore the suitability for storage declines by the lacking stability of the polymeres. Higher additions of vitamin E, Selenium or also of technical antioxidants show positive effects.  相似文献   

3.
Improvement of Bacon Quality of Pigs after Addition of Hydrogenated Marine Animal Oil to Feed The aspects of fat supplement of pigs are discussed. Hydrogenated marine oils have in Norway been used in human nutrition for a long time. Now it has been adopted in animal nutrition as well. The first experiment made 20 years ago with bacon pigs revealed that the pork fat quality was improved by adding hydrogenated marine oil to the pig feed. The recent investigations have confirmed that the quality criteria of the bacon is better by this fat supplement. The effect is explained by the resulting change in the fatty acid composition of the pork fat.  相似文献   

4.
Influence of feeding of oilseeds and byproducts from oilseeds on vitamin E concentration of animal products . In 5 feeding studies dairy cows, beef cattle and pigs were fed diets with different contents of oil seeds or oil seed expellers. Thus, the effects on vitamin E concentration in animal products were analyzed against a reference diet, which was free from these components. Dairy cows received 1 kg full fat rapeseed (430 g fat; 31 mg α-tocopherol/kg DM). Beef cattle were fed rations with 7,14 and 21% rapeseed and pigs were administered concentrates containing 10% rapeseed, 20% full fat soybeans or 5 and 10% false flax expeller. Feeding full fat oilseeds or their expellers resulted in an increased fat and α-tocopherol intake. Incorporating full fat rapeseed into the diets induced a significant increase of vitamin E-concentration in milk and other body samples. In contrary to this increase expeller feeding caused a decreased vitamin E-concentration in animal products. The fatty acids pattern of the oilseeds and the expellers have shown a clear influence on the fatty acid pattern of body fat in pigs, followed by milk and finally body fat of ruminants with an insignificant influence only. Fatty acid pattern, disposition for oxidation and vitamin E content of the various fat types influences their induction times. Feeding full fat oilseeds to ruminants, resulted in an increased induction time, in contrast, when fed to pigs the induction time decreased. Feeding expellers, the induction times of the various fat samples of both species decreased, due to the expected destruction of vitamin E.  相似文献   

5.
Production of human milk fat substitutes (HMFSs) from three types of palm stearin with palmitic acid (PA) of 91.3, 70.3 and 62.6 %, respectively, was scaled up to a kilogram scale. The physiochemical properties of these products including fatty acid profiles, triacylglycerol compositions, tocopherol contents, oxidative stability and melting and crystallization profiles were compared with those of HMFSs from lard, butterfat and tripalmitin and fats from infant formulas. Based on their chemical compositions, HMFSs from palm stearin with PA contents of 70.3 and 62.6 % produced by enzymatic acidolysis were found to have the highest degree of similarity to human milk fat, which indicated that these HMFSs were the most suitable for use in infant formulas. However, HMFSs from palm stearin with PA content of 91.3 % had the highest tocopherol contents. By investigation of the primary and secondary oxidation products during accelerated oxidation, the oxidative stability of HMFSs was found to be positively correlated to the contents of tocopherols, and the volatile oxidation compounds with the highest relative contents in HMFSs were aldehydes analyzed by solid-phase microextraction-GC–MS. All HMFSs had final melting points lower than body temperature.  相似文献   

6.
A dietary rosemary extract (DRE) containing carnosic acid and carnosol at 1:1 (w/w) for enhancing the lipid oxidative stability in cooked‐chilled lamb meat, is evaluated. Three diets for fattening lambs are tested: i) a cereal‐based concentrate (C‐diet); ii) the C‐diet plus 600 mg vitamin E per kg feed (E‐diet); and iii) the C‐diet plus 600 mg rosemary diterpenes per kg feed (R‐diet). Griddled‐chilled lamb patties are kept at 4 °C and lighting for 2 days, simulating catering conditions. Diterpenes have a lower deposition rate than vitamin E in lamb muscle and are completely degraded during cooking. DRE is thus less effective than dietary vitamin E in enhancing the oxidative stability of the patties. After 2‐day storage, the R‐diet shows lower (p < 0.01) peroxide values and thiobarbituric acid reactive substances than the C‐diet, while, in contrast to the E‐diet, it does not inhibit (p > 0.05) the formation of cholesterol oxidation products. The R‐diet increases (p < 0.05) the proportion of polyunsaturated fatty acids and decreases (p < 0.05) the n‐6/n‐3 ratio. These findings suggest antioxidant protection by dietary bioactive compounds beyond the direct radical scavenging activity that is able to stabilize lipids during the meat shelf‐life. Practical Applications: Cooked‐chilled meat lipids strongly oxidize in ready‐to‐eat dishes kept in retailing conditions, which may negatively affect their levels of polyunsaturated fatty acids (PUFA), cholesterol oxidation products (COP), and other lipid oxidation products. Dietary rosemary diterpenes can be used as a clean alternative to feed additives to enhance the oxidative stability of cooked‐chilled meat. Improved health and antioxidant status of the animal might be able to reduce oxidative spoilage during meat shelf‐life. Diterpenes provide lesser antioxidant protection than dietary vitamin E but may improve the PUFA content, with positive implications for the nutritional quality of lamb fat. The use of dietary antioxidants with different properties may contribute to improving the efficacy of animal feeds to improve meat quality.  相似文献   

7.
Influence of Feeding and Management on Quality Characteristics of Feed of Animal Origin Food of animal origin are milk and eggs as well as meat products, which are special parts of the carcass. Besides water which is the main component in most of these products, protein and fat are very important contents. The content of these main components could be influenced by regulation of the daily feed intake. For milk-composition also the type of diets, More roughages or more concentrates, is important. But these effects are also dependent on species of animals, breed and sex. Feeding systems do not affect the composition of these contents in eggs burs the weight of eggs, Which is also an important characteristic of quality.  相似文献   

8.
Milk fat was used in this work as a model to study the effects of humidity and physical properties on lipid oxidation. Although milk fat is considered a relatively stable fat because of its low content of unsaturated FA, it can oxidize significantly under certain conditions, as observed, for example, in the case, of dairy-based powders. Humidity and physical properties have a profound influence on the oxidative stability of powders, containing fat, and these factors affect the surface and encapsulated fractions of the fat differently. To examine these effects, encapsulated milk fat powders were stored under conditions of controlled relative humidity. Oxidation of the encapsulated fat as assessed by measurements of PV, losses of FA, and hexanal production increased, with increasing relative humidity (RH). At higher RH, moisture penetrates into the hydrophilic wall, interacting with and plasticizing the components, thereby making them less effective as moisture and oxygen barriers. Total oxidation of the powders was strongly influenced by the extent of oxidation in the encapsulated fraction (>98% of total lipids) although the surface fat fraction was oxidized more rapidly. Better protection against oxidation was obtained when fats were encapsulated and stored at 14 and 44% RH than at 52% RH.  相似文献   

9.
The oxidative stabilities of fish oil‐enriched milk and fish oil‐enriched drinking yoghurt were compared by following the development of lipid oxidation in plain milk, plain yoghurt and yoghurt to which ingredients present in drinking yoghurt were added one by one. All samples were enriched with 1 wt‐% fish oil. After 3 weeks of storage, development of peroxide values, volatile secondary oxidation products and fishy off‐flavors were much more pronounced in the milk compared to any of the yoghurt samples, irrespective of any added ingredients used to prepare flavored drinking yoghurt. Thus, pectin, citric acid or glucono‐delta‐lactone did not affect the oxidative stability of fish oil‐enriched yoghurt emulsions. Furthermore, the fruit preparation and added sugar did not lead to increased antioxidative activity. It is concluded that yoghurt as the dairy component in the fish oil‐enriched emulsion was responsible for the remarkably high oxidative stability and was able to protect the n‐3 PUFA against oxidative deterioration. It should be considered that this strong antioxidative effect of yoghurt might mask potential antioxidative effects of the other ingredients in the drinking yoghurt.  相似文献   

10.
Fatty acid intake of men and possibilities to influence the intake by animal nutrition. About 70% of total fat intake (≈ 100 g per person per day) are from fat of animal origin in Germany. Animal nutrition may influence fat content and fatty acid pattern in animal products. This paper summarizes the influence of feeding on fatty acid pattern of meat (pork, beef, poultry, rabbit, fish), milk and eggs. Fatty acid intake is demonstrated under consideration of fat intake of men and variation of fatty acid pattern of various fats of animal origin. Daily fat intake of men amounted to 43 g saturated, 37 g monoen and 13 g polyen fatty acids. It may vary between 38 and 46 g saturated, 33 and 45 g monoen and 11 and 17 g polyen fatty acids if variation of fatty acid pattern of animal fats is considered. By combination of lower fat intake and changed fatty acid pattern of animal products fatty acid intake may be changed to more monoen and polyen fatty acids.  相似文献   

11.
Marine phospholipids (PL) are potential ingredients for food fortification due to its numerous advantages. The main objective of this study was to investigate whether a fermented milk product fortified with a mixture of marine PL and fish oil had better oxidative stability than a fermented milk product fortified with fish oil alone. Fortification of a fermented milk product with marine PL was performed by incorporating 1 % w/w lipids, either in the form of neat oil or in the form of a pre-emulsion. Lipid oxidation was investigated in the neat emulsions and fortified products by the measurements of primary, secondary volatile oxidation products and tocopherol content upon 32 days storage at 2 °C and 28 days storage at 5 °C, respectively. Analyses of particle size distribution, viscosity and microbial growth were also performed. In addition, sensory attributes such as sour, fishy and rancid flavor/odor were evaluated in fortified products by a trained panel. The results obtained showed that incorporation of a mixture of marine PL and fish oil into fermented milk products decreased the oxidative stability and sensory quality of fortified products. The pH-dependent behavior of iron seemed to be the main factor that influenced the lipid oxidation in the marine PL emulsion and fermented milk system. In addition, both oxidative stability and sensory acceptability of fortified products varied depending on the quality of the marine PL used for fortification.  相似文献   

12.
Effects of Oxidized Fatty Acids of Mixed Feed on Interstitial Carotinoids in Egg Yolk It was the target of investigations to test whether a different degree or course of oxidation of the fat/oil contained in mixed feed influences the deposit of carotinoids in egg yolk. The results show a significant influence of fat oxidation on carotinoid deposit in egg yolk. The yolk colour decreases with increasing peroxide value and is improved at lower peroxide values. Especially oils with high contents of unsaturated fatty acids cause a diminished carotinoid deposit in egg yolk. By addition of antioxidants the fatty acid oxidation can be delayed. Basic feed components among others bad tapioca meal with high lipoxygenase activity can have an important influence too on peroxide formation and with that on yolk colouring.  相似文献   

13.
Electron Microscopic Investigations of the Influence of Temperature and Feeding Conditions on the Crystal Structure of Fat Globules in Cream Electron microscopy can provide informations on crystal formations in fat globules of cream depending on temperature and feeding conditions. When cooling cream from barn-fed animals to 15°C, frequently globules occur with and without a peripheral crystalline shell (Types 4 and 2, respectively) and with numerous crystalline aggregates and little oil in the interior. In summer cream rich in oleic acid as well as in cream from underfed cows, however, only globules without a crystalline shell (Type 2) occur more frequently. Under all feeding conditions, globules with and without a crystalline shell (Types 1 and 3, respectively) and with a completely fluid interior are less frequently observed. The simultaneous existence of different fat globule types in cream is mainly caused by super-cooling phenomena, while in bulk milk it also result partly from variations in the fatty acid composition of different globules. The abundance of the different globule types can independently of the fat composition be influenced by carefully controlling the cream ripening temperature. Thus, the spreadability and oiling-off behaviour of butter as well as the quality of whipping cream of whipped cream (plug formation and serum separation) can significantly be influenced. Quality variations in milk products caused by fat fractionation, crystal displacements, crystal nucleus formation and membrane destabilization can therefore be explained with the aid of electron microscopy.  相似文献   

14.
Recent research has shown that the oxidative stability of oil‐in‐water emulsions is affected by the type of surfactant used as emulsifier. The aim of this study was to evaluate the effect of real food emulsifiers as well as metal chelation by EDTA and pH on the oxidative stability of a 10% n‐3‐enriched oil‐in‐water emulsion. The selected food emulsifiers were Tween 80, Citrem, sodium caseinate and lecithin. Lipid oxidation was evaluated by determination of peroxide values and secondary volatile oxidation products. Moreover, the zeta potential and the droplet sizes were determined. Tween resulted in the least oxidatively stable emulsions, followed by Citrem. When iron was present, caseinate‐stabilized emulsions oxidized slower than lecithin emulsions at pH 3, whereas the opposite was the case at pH 7. Oxidation generally progressed faster at pH 3 than at pH 7, irrespective of the addition of iron. EDTA generally reduced oxidation, as evaluated by volatiles formation in all emulsions, irrespective of pH and emulsifier type, except in the lecithin and caseinate emulsions where a pro‐oxidative effect was observed for some volatiles. The different effects of the emulsifier types could be related to their ability to chelate iron, scavenge free radicals, interfere with interactions between the lipid hydroperoxides and iron as well as to form a physical barrier around the oil droplets.  相似文献   

15.
Oxidation is the major cause of fat and oil deterioration which produces rancid and unpleasant flavors that drastically reduces their quality and nutritional value. The primary oxidation products are triacylglycerols (TAG) containing unsaturated fatty acyl hydroperoxides formed by a chain process occurring through free radical intermediates. The Rancimat method is currently the gold standard for measuring the oxidative stability of oils and fats. In this report, easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is demonstrated to function as a direct (no pre-separation or sample preparation steps), fast and accurate method to monitor oils and fats oxidation, providing detailed overviews of the most immediate TAG hydroperoxide products. The EASI-MS results were compared to those obtained via the classical Rancimat test.  相似文献   

16.
Investigations on the Autoxidation of Margarine The authors investigated the influence of storage temperature, packing and of the quality of dispersion on the oxidative stability of margarine. The oxidative stability of margarine is improved with increasing fineness of the dispersion. The autoxidation can be prevented to a great extent by employing low storage temperature and suitable packing material. Packing materials containing traces of heavy metals promote the autoxidation in the upper layer of margarine.  相似文献   

17.
Investigations on the Use of Different Feeding Fats for Growing Fattening Pigs In a feeding experiment with 100 castrated male pigs (Deutsche Landrasse) two types of feeding oils (fat/fatty acid mixtures) were compared to four types of animal and vegetable fats (animal fat, soya oil, rapeseed oil and a licithine mixture). Their influence on growth, feed utilisation, quality of carcass and composition of body fat during a growing-fattening period from 20 kg-100 kg was investigated. The different types of fats were incorporated in a barley-soya-ration at a level of 4%. In addition one ration contained milled whole soya beans at a level equivalent to 4% fat. All groups were fed according to live weight the same amounts of digestible protein and metabolizable energy. During the whole growing-fattening period, the average daily gain of all groups was 0.78 kg, while the group given animal fat showed a small advantage over those given vegetable fat or feeding oils (fat/fatty acid mixtures). Feed convertion corresponded to these findings. But the differences of daily gain and feed convertion amounting to a maximum of 5% failed to reach significance. Remarkable differences of carcass quality were not detected. Fatty acid composition of backfat was strongly influenced by the type of fat in the ration. In the group fed a ration with animal fat the fatty acid composition of backfat was approximately the same as that of the control group. The groups of which the rations were supplemented with vegetable fats had an increased content of linoleic acid and linolenic acid and a decreased content of palmitic acid, stearic acid and oleic acid. Consequently, the iodine number of backfat in the groups supplemented with vegetable fats came up to 80. There was no difference observed in storage stability of backfat between the groups.  相似文献   

18.
In order to clarify the prooxidative role of carotenoids on the oxidation of unsaturated lipids this study examined the effects of β‐carotene and its oxidative breakdown product, retinal, on primary oxidation products of linoleic acid methyl ester. Formation as well as isomer distribution of methyl linoleate hydroperoxides were followed by highperformance liquid chromatography. Oxidation of methyl linoleate without or with added β‐carotene (5, 20, 200 μg/g) or retinal (7, 18, 180, 360 μg/g) was carried out in the dark under air at 40 °C. Both β‐carotene and retinal promoted the formation of hydroperoxides and thus acted as prooxidants in a concentration‐dependent way. Moreover, carotenoids also had an effect on the isomeric distribution of primary oxidation products as high contents of retinal increased the portion (%) of trans,trans‐hydroperoxides. Being thermodynamically more stable isomers than cis,trans‐isomers of hydroperoxides they are known to accumulate during later phases of oxidation or during hydroperoxide decomposition. The results showed that β‐carotene and retinal were not effective hydrogen donors. These findings raise the question that carotenoids and their oxidative breakdown products enhance the decomposition of lipid hydroperoxides and this effect partially explains the prooxidative effect of carotenoids.  相似文献   

19.
Investigations of Fat Oxidation in Feedstuffs The investigation of oxidation of feedstuffs revealed that some ingredients were more reactiv than others. Various additions or treatments to cereals had an effect. Water, soil, dust, MgO, mineral mixtures, trace element supplements, and the single minerals promoted the oxidation. It was increased in the order Zn, Mn, Cu, Fe, Co, when they were mixed in the cereal. Water soluble salts of Fe and Co were particularly effective. EDTA, though, had little influence. Antioxidative effect had heating in an autoclave, addition of melasses, methionine ester or synthetic antioxidants.  相似文献   

20.
Recent data have suggested that the fatty acid composition and molecular structure of fats in infant formulas should be as similar to human milk fat as possible to obtain optimal fat and calcium absorption from the infant formula. This work investigated the possibilities of using enzyme technology and butterfat as a material to produce a fat similar to human milk fat with respect to the above parameters. Moreover, the oxidative stability of the enzyme modified human milk fat substitute (HMFS) was compared to the fat blend used for the production of HMFS. Using a combination of enzyme technology, fractionation and batch deodorization and with butterfat in combination with soybean oil and rapeseed oil as raw materials it was possible to produce HMFS with a molecular structure and fatty acid composition that was very similar to that of human milk fat. The oxidative stability of the HMFS oil was lower than that of the reference oil with the same fatty acid composition. However, oxidation did not lead to a severe increase in rancidity scores during storage. Rather, the panel gave high intensity scores for other off-flavors such as burnt and bitter. Further optimization of the deodorization process is therefore necessary to remove these off-flavors.  相似文献   

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