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1.
Physical properties of fats are affected by the reduction of saturated fatty acids. One method for retaining desired properties is the use of high-intensity ultrasound (HIU). The aim of this study was to investigate the influence of HIU power levels, pulse time, and position on the physical properties of a low-saturated palm-based fat crystallized in a scraped surface heat exchanger (SSHE). The sample was crystallized in a SSHE at 26 °C, using a 11 L hour−1 flow rate, and agitation of 344 rpm in the barrels and 208 rpm in the pin worker. HIU was applied using a 12.7 mm tip coupled to a water jacketed (26 °C) flow cell that was placed at the end of the SSHE process. Sonication conditions were 20%, 50%, or 80% amplitude using pulses (5 and 10 s) or continuous sonication. After choosing the best HIU condition, the position of the flow cell was changed to different positions within the SSHE: before the first barrel (HIU-0), between the two barrels (HIU-1), between the second barrel and the pin worker (HIU-2), and after the pin worker (HIU-3). The best sonication condition from the first set of experiments was when HIU was applied using 50% amplitude and 10 s pulses. This condition resulted in higher oil binding capacity (OBC) and storage modulus (G') compared to the non-sonicated sample (OBC: 77% against 69.5%; G':154 kPa against 108 kPa). The best HIU position was HIU-3 since no further agitation was applied. The lack of agitation after sonication induced secondary nucleation and generated a strong crystalline network.  相似文献   

2.
Re-esterified palm oils are obtained from the chemical esterification of palm acid oils (rich in free fatty acids) with glycerol, both economically interesting by-products from oil refining and biodiesel industries, respectively. Thus, re-esterified palm oils could be an economically interesting alternative to native palm oil in broiler chick diets. However, because they may have different physicochemical properties than have their corresponding native oil, we assessed the effect of fatty acid (FA) positional distribution within acylglycerol molecules and the effect of acylglycerol composition on FA apparent absorption, and their possible consequences on the evolution of postprandial lipemia and growth performance in broiler chicks. Seventy-two 1-day-old female broiler chicks were randomly distributed into 18 cages. The three treatments used were the result of a basal diet supplemented with 6 wt% of native palm oil (N-TAG), re-esterified palm oil (E-TAG), or re-esterified palm oil high in mono- and diacylglycerols (E-MDAG). Chemical esterification raised the fraction of palmitic acid at the sn-2 position from 9.63 mol% in N-TAG oil to 17.9 mol% in E-TAG oil. Furthermore, E-MDAG oil presented a high proportion of mono- (23.1 wt%) and diacylglycerols (51.2 wt%), with FA mainly located at the sn-1,3 positions, which resulted in a lower gross-energy content and an increased solid-fat index at the chicken’s body temperature. However, re-esterified palm oils did not alter fat absorption, postprandial lipemia, or growth performance, compared to native palm oil, so they can be used as alternative fat sources in broiler chick diets.  相似文献   

3.
Enzyme catalyzed interesterification (EIE) of pine seed oil (PSO) and a fully hydrogenated soybean oil (FHSBO) were studied in batch reactors in solvent-free media to prepare different semisolid fats rich in polyunsaturated fatty acids (PUFA). Optimal operation conditions found were: 10 % (w/w) enzyme loading, 75 °C and magnetic agitation at 300 rpm. Quasi-equilibrium conditions were reached after 2, 3 and 6 h, when immobilized lipases from Thermomyces lanuginosus (Lipozyme® TL IM), Candida antarctica B. (Novozym® 435) and Rhizomucor miehei (Lipozyme® RM IM) from Novozymes A/S (Bagsvaerd, Denmark) were employed, respectively. Similar distributions of unsaturated to saturated fatty acid (UFA/SFA) residues along the glycerol backbone of the fat products were obtained with both non-selective and sn-1(3) regioselective lipases due to significant spontaneous acyl migration during the reaction. The products had higher UFA/SFA ratios at the sn-2 position (2.4–2.5, 1.4–1.7, and 0.5–0.8 for the trials involving 20, 40 and 70 % FHSBO, w/w, respectively) than the corresponding physical blends (0.8, 0.4 and 0.5, respectively). Fat products containing 3.1–11.6 % (w/w) pinolenic acid (Pn) and 16.1–35.7 % (w/w) linoleic acid (L) at the sn-2 position were prepared. The free acid contents of EIE products prepared with Lipozyme® TL IM and Novozym® 435 were 6.1–6.4 and 2.5–2.6, respectively. Residual activities of Lipozyme® TL IM and Novozym® 435 diminish by ca. 20 % after 9 reaction cycles.  相似文献   

4.
In recent decades, fertility traits in humans as well as in farm animals have decreased worldwide. As such, it is imperative to know more about the genetics and physiology of increased or high fertility. However, most of the current animal models with reproductive phenotypes describe lower fertility or even infertility (around 99%). The “Dummerstorf high-fertility lines” (FL1 and FL2) are two unique mouse lines selected for higher reproductive performances, more specifically for higher number of pups per litter. We recently described how those superfertile mice managed to increase their reproductive phenotype by doubling the ovulation rate and consequently the litter size compared to the unselected mice of the same founder population. FLs show an unusual estrous cycle length and atypical levels of hormones that link reproduction and metabolism, such as insulin in FL1 and leptin in FL2. Moreover, we described that their higher ovulation rate is mostly due to a higher quality of their oocytes rather than their sheer quantity, as they are characterized by a higher quantity of high-quality oocytes in antral follicles, but the quantity of follicles per ovary is not dissimilar compared to the control. In the present study, we aimed to analyze the lipid composition of the fertility lines from plasma to the gonads, as they can connect the higher reproductive performances with their metabolic atypicalities. As such, we analyzed the fat content of FLs and fatty acid composition in plasma, liver, fat, oocytes of different quality, and granulosa cells. We demonstrated that those mice show higher body weight and increased body fat content, but at the same time, they manage to decrease the lipid content in the ovarian fat compared to the abdominal fat, which could contribute to explaining their ovarian quality. In addition, we illustrate the differences in fatty acid composition in those tissues, especially a lower level of saturated fatty acids in plasma and a different lipid microenvironment of the ovary. Our ongoing and future research may be informative for farm animal biology as well as human reproductive medicine, mostly with cases that present characteristics of lower fertility that could be reversed following the way-of-managing of Dummerstorf high-fertility lines.  相似文献   

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