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At least 865 records · Page 48Linked to original sources
PubMed1996

Nutritional implications of pectins in chicks in relation to esterification and origin of pectins.

An experiment was conducted to examine the effect of feeding high-methylated (HM) and low-methylated (LM) pectin on performance and physiological characteristics in broiler chicks. Two levels each (1.5 and 3%) of HM citrus pectin (HMC), LM citrus pectin (LMC), or HM sugar beet pectin (HMS) were added to a semi-purified basal diet. The experiment was conducted in battery brooders, and chicks received the diets as pellets from 6 to 27 d of age. The inclusion of LMC or HMS in the diet had little or no effect on the performance of chicks; however, when HMC was added to the diet growth and feed utilization were reduced significantly (P < 0.05). Water intake and water:feed ratio were increased (P < 0.05) after inclusion of all three pectin products in the diet. The effect on water consumption was more pronounced in the HMC-containing diets than in the LMC or HMS diets, and was dose-dependent. In vitro viscosity was increased significantly by incorporating HMC or LMC into the diet, whereas HMS had no effect on this parameter. Waterholding capacity of the diets and the excreta were increased significantly by including one (P < 0.05) of the three pectin products in the diet. The concentration of some of volatile fatty acids (VFA) in the cecal chyme was markedly decreased (P < 0.05) by feeding HMC, whereas LMC had no effect (P > 0.05) on the concentration of VFA. In contrast, inclusion of HMS in the diet significantly increased the concentration of VFA in the cecal content (P < 0.05) dose-dependently. Based on the results of the present study, it can be concluded that the effect of dietary pectin on chick performance is dependent on the degree of carboxyl groups that is esterified, the origin of the pectin product, and the amount added to the diet.

Animal Nutritional Physiological Phenomena↗
PubMed2000

Bis(monoacylglycerol) phosphate in rat uterine stromal cells: structural characterization and specific esterification of docosahexaenoic acid.

In rat uterine stromal cells (U(III) cells), docosahexaenoic acid (DHA) was esterified extensively in alkenylacyl-glycerophosphoethanolamine and in an unknown phospholipid accounting for only 0.7% of the total phospholipid. The latter was identified as a bis(monoacylglycerol) phosphate (BMP) using MS. Incorporation studies using C(18:3)n-3 and C(20:5)n-3 demonstrated that BMP had a high specificity to incorporate DHA and C(22) polyunsaturated fatty acids of the (n-3) series. By contrast, polyunsaturated fatty acids of the (n-6) series were never incorporated into BMP. Incubation of U(III) cells with 5 microM DHA for 24 h increased the DHA content of BMP from 36 to 71% of the total acyl chains. [(3)H]DHA-labelled BMP purified as a single TLC spot was resolved into three peaks using HPLC. These peaks were also observed when cells were labelled with [(3)H]phosphatidylglycerol, an exogenous BMP precursor, and with [(33)P]P(i). Electrospray MS of BMP from control cells showed that the first two peaks contained the same molecular species (mainly C(22:6)n-3/C(22:6)n-3 and C(18:1)n-9/C(22:6)n-3) while the third peak mainly contained the C(18:1)n-9/C(18:1)n-9 species. The stereoconfiguration analysis of the compounds revealed an sn-glycero-3-phospho-1'-sn-glycerol configuration for the first peak and sn-glycero-1-phospho-1'-sn-glycerol configurations for the other two. BMP from rat testis was used to establish the positions of the acyl groups. More than 70% of its acyl chains were C(22:5) n-6. It was separated on HPLC into three peaks that co-migrated with the three peaks of BMP from U(III) cells. Lipase activity and NMR analysis of the second peak showed that fatty acids esterified the primary alcohol group on each glycerol moiety. We conclude that the three peaks are stereoisomeric compounds with different acyl-chain locations and may be the result of different metabolic fates depending on subcellular localization.

Animals↗
PubMed1975

[Automation of fluorometric enzymatic determination of free and total cholesterol. Application to the determination of the esterification rate].

A fluorimetric, authomatical method for determination of free and total cholesterol in serum is described. Cholesterol esters are splitted into free cholesterol and fatty acids by cholesterol esterase. In the presence of oxygen free cholesterol will be transformed by cholesterol oxydase in delta 4 cholestenone with formation of hydrogen peroxyde. Hydrogen peroxyde oxidizes in the presence of catalase inethanol to formaldehyde which gives with ammonium ions and acetylacetone 3-5 diacetyl 1-4 dihydrolutidine measured by fluorimetry. Withour cholesterol esterase, the reaction allows a measurement of free cholesterol in plasma. So the ratio of ester to total cholesterol is determined by the two steps. Accuracy and precision are very good. Results are well correlated with those obtained with reference methods.

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