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We investigate the phase behavior of model ternary triacylglycerol blends, comprising triolein (C57H104O6, OOO), tripalmitin (C51H98O6, PPP) and tristearin (C57H110O6, SSS), building upon extensive characterisation of single and binary mixtures, in order to rigorously map the thermal transitions of model natural ‘fats’. A combination of calorimetry, X-ray diffraction, and FTIR spectroscopy is employed to determine crystallisation and melting temperatures and identify the corresponding phases in the complex ternary system. We recover the eutectic behaviour of SSS-PPP blends and the invariability of OOO neat transitions, and resolve the complex β′ + β ternary surface, reflecting the roles of unsaturation and polymorphism of its constituents. Our results provide a representation of the OOO:PPP:SSS:temperature phase behaviour into a triangular prism, consistent with binary pair-wise data, which can inform a range of food science, cosmetic, pharmaceutical and cleaning applications that depend strongly on the physical-chemistry of such multicomponent ‘triglycerides’.

Milk fat is an important nutrient for young animals and humans, and its composition [fatty acids (FA)] may vary broadly. The objective of this study was to describe the development of global FA models for high-throughput Fourier transform infrared milk analysers. The developed models for major FA, FA grouped by chain length, by degree of unsaturation and by their origin, showed good accuracy, repeatability and correlation to gas chromatography. Moderate performance was obtained for low concentration FA (short chain, polyunsaturated and trans). Possible practical applications could be to enhance dairy products, optimise milk processing and/or optimise dairy cow performance through improved feeding and management.

Immediate and short-term changes in diet composition can support individualized, real-time interventions in precision dairy production systems, and might increase feed efficiency (FE) of dairy cattle in the short-term. The objective of this study was to determine immediate and short-term effects of changes in diet composition on production parameters of dairy cattle fed varying amounts of top dressed commodities. A 4 × 4 replicated Latin square design was used to evaluate responses of twenty-four Holstein cows fed either no top dress (Control) or increasing amounts of: corn grain (CG), soybean meal (SBM), or chopped mixed grass hay (GH) top dressed on a total mixed ration (TMR) over four, 9-day periods. Throughout each period, top dressed commodities were incrementally increased, providing 0% to 20% of calculated net energy of lactation (NEL ) intake. Measured production responses were analyzed for each 9-d period using a mixed-effects model considering two different time ranges. Samples collected from d 3 and 4 and from d 7 and 8 of each period were averaged and used to reflect “immediate” vs. “short-term” responses, respectively. In the immediate response time frame, control fed cows had lower milk yield, milk fat yield, and milk true protein yield than CG and SBM supplemented animals but similar responses to GH supplemented animals. Milk fat and protein percentages were not affected by top dress type in the immediate term. In the short-term response time-frame, GH supplemented animals had lower DMI and milk fat yield than all other groups. Control and GH supplemented cows had lower milk yield than CG and SBM fed cows. In the immediate response time frame, FE of SBM supplemented cows was superior to other groups. In the short-term time frame, FE of GH and SBM groups was improved over the control group. Results suggest that lactating dairy cows show rapid performance responses to small (

In this study, effects of different cooling rates (0.5,3.3,4.7 and 6.9 degrees C/min) on the crystallization behavior of palm-kernel-stearin (PKS) were studied by low-field NMR relaxometry. According to results, solid fat content (SFC), longitudinal relaxation time (T1), second moment (M2) and degree of crystallinity (%) of the samples increased with increase in cooling rate from 0.5 to 6.9 degrees C/min. In contrast, transverse relaxation time (T2) demonstrated an opposite behavior with respect to T1 and decreased when the cooling rate increased. Additionally, effects of cooling rate on the changes of polymorph structures were detected by X-ray measurements. Degree of crystallinity showed high Pearson correlation values (alpha

Background: The fatty acid (FA) composition of adipose tissue influences the nutritional quality of meat products. The unsaturation level of FAs is determined by fatty acid desaturases such as stearoyl- CoA desaturases (SCDs), which are under control of the tianscription factor sterol regulatory element binding protein (SREBP). Differences in SCD genotype may thus confer variations in lipid metabolism and FA content among cattle breeds. This study investigated correlations between FA composition and lipogenic gene expression levels in the subcutaneous adipose tissue of beef cattle breeds of different gender from the Basque region of northern Spain. Pirenaica is the most important beef cattle breed in northern Spain, while Salers cattle and Holstein Friesian cull cows are also an integral part of the regional beef supply. Results: Pirenaica heifers showed higher monounsaturated FA (MUFA) and conjugated linoleic acid (CLA) contents in subcutaneous adipose tissue than other breeds (P< 0.001). Alternatively, Salers bulls produced the highest oleic acid content, followed by Pirenaica heifers (P< 0.001) There was substantial variability in SCD gene expression among breeds, consistent with these differences in MUFA and CLA content. Correlations between SCD1 expression and most FA desaturation indexes (DIs) were positive in Salers (P< 0.05) and Pirenaica bulls, while, in general, SCD5 expression showed few significant correlations with DIs. There was a significant linear correlation between SCD1 and SRBEP1 in all breeds, suggesting strong regulation of SCD 1 expression by SRBEP1. Pirenaica heifers showed a stronger correlation between SCD1 and SREBP1 than Pirenaica bulls. We also observed a opposite relationship between SCD1 and SCD5 expression levels and opposite associations of isoform expression levels with the Delta 9 desaturation indexes. Conclusions: These results suggest that the relationships between FA composition and lipogenic gene expression are influenced by bleed and sex The opposite relationship between SCD isoforms suggests a compensatory regulation of total SCD activity, while opposite relationships between SCD isoforms and desaturation indexes, specially 9c-14:1 Dl, previously reported as an indicator of SCD activity, may reflect distinct activities of SCD1 and SCD5 in regulation of FA content. These findings may be useful for beef/dairy breeding and feeding programs to supply nutritionally favorable products. Department of Economic Development & Competitiveness of the Basque Government supported the doctoral fellowship of D.G. and A.L. The Spanish Ministry of Economy & Competitiveness and the UPV/EHU for 'Ramon y Cajal (RYC-2011-08593)' research contract of N.A. This work was supported by grants from the Dept. of Education, Universities & Research of the Basque Government (IT766-13 & IT833-13).

Background Bacteria involved in ruminal formation of trans-10 intermediates are unclear. Therefore, this study aimed at identifying rumen bacteria that produce trans-10 intermediates from 18-carbon unsaturated fatty acids. Results Pure cultures of 28 rumen bacterial species were incubated individually in the presence of 40 μg/mL 18:3n-3, 18:2n-6 or trans-11 18:1 under control or lactate-enriched (200 mM Na lactate) conditions for 24 h. Of the 28 strains, Cutibacterium acnes (formerly Propionibacterium acnes) was the only bacterium found to produce trans-10 intermediates from 18:3n-3 and 18:2n-6, irrespective of the growth condition. To further assess the potential importance of this species in the trans-11 to trans-10 shift, different biomass ratios of Butyrivibrio fibrisolvens (as a trans-11 producer) and C. acnes were incubated in different growth media (control, low pH and 22:6n-3 enriched media) containing 40 μg/mL 18:2n-6. Under control conditions, a trans-10 shift, defined in the current study as trans-10/trans-11 ≥ 0.9, occurred when the biomass of C. acnes represented between 90 and 98% of the inoculum. A low pH or addition of 22:6n-3 inhibited cis-9, trans-11 CLA and trans-10, cis-12 CLA formation by B. fibrisolvens and C. acnes, respectively, whereby C. acnes seemed to be more tolerant. This resulted in a decreased biomass of C. acnes required at inoculation to induce a trans-10 shift to 50% (low pH) and 90% (22:6n-3 addition). Conclusions Among the bacterial species studied, C. acnes was the only bacterium that have the metabolic ability to produce trans-10 intermediates from 18:3n-3 and 18:2n-6. Nevertheless, this experiment revealed that it is unlikely that C. acnes is the only or predominant species involved in the trans-11 to trans-10 shift in vivo.

The aim of the present study was to investigate how maternal diet can influence the adipose tissue of goat kids. Omental adipose tissue proteomes of goat-kids from mothers fed with diet enriched with stearic acid (ST-kids), fish oil (FO-kids) and standard diets (CTRL) were determined by quantitative iTRAQ 2D-LC-MS/MS analysis. Twenty proteins were found to be differentially expressed in suckling kids' omental adipose tissue. Stearic acid induces changes in a higher number of proteins when compared to fish oil. Eleven proteins, namely AARS, ECl1, PMSC2, CP, HSPA8, GPD1, RPL7, OGDH, RPL24, FGA and RPL5 were decreased in ST-kids only. Four proteins, namely DLST, EEF1G, BCAP31 and RALA were decreased in FO-kids only, and one, NUCKS1, was increased. Four proteins, namely PMSC1, PPIB, TUB5 x 2 and EIF5A1, were be less abundant in both ST- and FO- kids. Most of the protein whose abundance was decreased in ST kids (10 out of 15) are involved in protein metabolism and catabolism pathways. Qualitative gene expression analysis confirmed that all the proteins identified by mass spectrometry, with the exception of FGA, were produced by adipose tissue. Quantitative gene expression analysis demonstrated that two proteins, namely CP, a minor acute phase protein, and ECl1, involved in fatty acid beta oxidation, were downregulated at mRNA level as well. ECl1 gene expression was downregulated in ST-kids AT as compared to Ctrl-kids and CP was downregulated in both ST- and FO-kids. The present results demonstrate that it is possible to influence adipose goat-kid proteome by modifying the maternal diet.

Dairy fat intake, reflected by the biomarkers C14:0, C15:0, C17:0, trans-C16:1 (n-7), trans-C18:1 (n-7) and CLA, may have beneficial effects on cardiovascular health. It has, however, been questioned whether this association is genuine, since C15:0 and C17:0 are also biomarkers from fish. We investigated whether the above biomarkers are reliable markers for dairy fat intake in 864 healthy subjects. Subsequently, we explored the association between these biomarkers and cardiovascular risk factors. Intakes of dairy and fish were determined by Food Frequency Questionnaires FFQs. Fatty acids were analyzed in plasma triglycerides (TG) and phospholipids (PL). Median intakes of dairy and fish fat were 12.3 (8.4&ndash, 17.4) g/day and 1.14 (0.53&ndash, 1.75) g/day. All fatty acids, except TG C17:0, were associated with dairy fat (std.&beta, range TG: 0.12 for C14:0 till 0.25 for C15:0 and Trans-C18:1 (n-7), and std.&beta, range PL: 0.12 for C17:0 and Trans-C16:1 (n-7) till 0.24 for Trans-C18:1 (n-7) and CLA, p &lt, 0.001). TG C17:0 was associated with fish fat (std.&beta, = 0.08, p = 0.03), whereas PL C17:0 was not. Associations remained after adjustment for fish/dairy fat intake. Strongest inverse associations with biological variables were found with PL C17:0 and Trans-C18:1 (n-7) (Std.&beta, s: waist circumference: &minus, 0.18, p &lt, 0.001 and &minus, 0.10, p &lt, 0.05, BMI: &minus, 0.17, p &lt, 0.001, &minus, 0.11, p &lt, 0.01, glucose: &minus, 0.01 and &minus, 0.08, p &lt, high sensitive C-reactive protein (hs-CRP): &minus, 0.22, p &lt, 0.16, p &lt, uric acid: &minus, 0.27, p &lt, 0.24, p &lt, 0.001). In conclusion, fatty acid biomarkers, except plasma TG C17:0, were associated with dairy fat intake, independent of fish fat intake. PL C17:0 and trans-C18:1 (n-7) were inversely associated with adiposity, diabetes, inflammation and uric acid.

To investigate the metabolic (.11, !I:2.es in the adipose tissue (AT) of dairy cows under milk fat depression (MFD), 30 cows were randomly allocated to a control diet, a conjugated linoleic acid (CLA)-supplemented diet, or a high-starch diet supplemented with a mixture of sunflower and fish oil (2:1; as HSO diet) from 1 to 112 d in milk. Performance of animals, milk yield, milk composition, energy balance, and blood metabolites were measured during lactation. Quantitative PCR analyses were conducted on the AT samples collected at wk 3 and 15 of lactation. The CLA and HSO diets considerably depressed milk fat yield and milk fat content at both wk 3 and 15 in the absence of significant changes in milk protein and lactose contents. In addition, the HSO diet lowered milk yield at wk 15 and decreased dry matter intake of cows from wk 3 to 15. Compared with the control, both CLA and HSO groups showed reduced body weight loss, improved energy balance, and decreased plasma concentrations of nonesterified fatty acids and beta-hydroxybutyrate at early lactation. The gene expression analyses reflected suppressed lipolysis in AT of the CLA and HSO groups compared with the control at wk 3, as suggested by the downregulation of hormone-sensitive lipase and fatty acid binding protein 4 and the upregulation of perilipin 2. In addition, the HSO diet promoted lipogenesis in AT at wk 15 through the upregulation of 1-acylglycerol-3-phosphate O-acyltransferase 2, mitochondria' glycerol-3-phosphate acyltransferase, perilipin 2, and peroxisome proliferator-activated receptor gamma. The CLA diet likely regulated insulin sensitivity in AT as it upregulated the transcription of various genes involved in insulin signaling, inflammatory responses, and ceramide metabolism, including protein kinase B2, nuclear factor kappa B1, toll-like receptor 4, caveolin 1, serine palmitoyltransferase long chain base subunit 1, and N-acylsphingosine amidohydrolase 1. In contrast, the HSO diet resulted in little or no change in the pathways relevant to insulin sensitivity. In conclusion, the CLA and HSO diets induced a shift in energy partitioning toward AT instead of mammary gland during lactation through the regulation of different pathways.

Context: Cheese may affect lipids and lipoproteins differently than other high-fat dairy foods. Objective: The present systematic review and meta-analysis was performed to evaluate randomized controlled trials that examined the effect of cheese consumption compared with another food product on blood lipids and lipoproteins. Data Sources: A systematic literature search of the MEDLINE, Embase, Scopus, CAB Abstracts, the Cochrane Controlled Trials Register, and the clinicaltrials.gov website was performed. Study Selection: A total of 12 randomized controlled trials (RCTs) were identified that examined the effect of cheese consumption on blood lipids and lipoproteins in healthy adults. Data Extraction : A meta-analysis of 5 RCTs that compared the effects of hard cheese and butter, both of which had a similar ratio of polyunsaturated fatty acids to saturated fatty acids (P/S ratio), was performed. Data Synthesis: Compared with butter intake, cheese intake (weighted mean difference: 145.0 g/d) reduced low-density lipoprotein cholesterol (LDL-C) by 6.5% (−0.22 mmol/l; 95%CI: −0.29 to −0.14) and high-density lipoprotein cholesterol (HDL-C) by 3.9% (−0.05 mmol/l; 95%CI: −0.09 to −0.02) but had no effect on triglycerides. Compared with intake of tofu or fat-modified cheese, cheese intake increased total cholesterol or LDL-C, as was expected on the basis of the P/S ratio of the diets. There was insufficient data to compare intake of cheese with intake of other foods. Conclusion: Despite the similar P/S ratios of hard cheese and butter, consumption of hard cheese lowers LDL-C and HDL-C when compared with consumption of butter. Whether these findings can be attributed to calcium, specific types of saturated fatty acids, or the food matrix of cheese warrants further research.

Background: The Vascular lifestyle-Intervention and Screening in phArmacies (VISA) study investigates diet and lifestyle factors associated with risk of cardiovascular disease (CVD). As part of the study methodology, a short Food Frequency Questionnaire (FFQ), the VISA-FFQ, was adapted from the Norwegian NORDIET-FFQ. Objective: The aim of this study was to evaluate the VISA-FFQ and its ability to estimate intakes of foods and lifestyle factors in screening for elevated risk of CVD. The evaluation included assessment of relative validity of intake of milk fat and assessment of reproducibility of several foods and lifestyle factors. Design: Relative validity of milk fat estimated from the VISA-FFQ was assessed in 307 participants by comparing estimated dietary intake of the fatty acids pentadecanoic acid (15:0) and heptadecanoic acid (17:0), from milk fat with whole blood biomarkers 15:0 and 17:0. Reproducibility was evaluated in 122 participants by comparing consistency in intakes of different foods and lifestyle factors reported by the VISA-FFQ and administered twice with a 4-week interval. Results: Dietary 15:0 milk fat estimated from the VISA-FFQ correlated positively with whole blood 15:0 (r = 0.32, P < 0.05). Men presented higher correlations than women did. Acceptable and consistent reproducibility (r = 0.44–0.94 and no large difference between test and retest) was observed for most beverages, milk products, spreads on bread and meat (all of which included food items categorised into at least two fat categories) and also for eggs, fruits and vegetables, nuts, pasta and rice, dessert/sweets, smoking and physical activity. Reproducibility did not consistently meet a satisfactory standard (r ≤ 0.41 or large difference between test and retest) for unsweetened cereals, fatty fish, cakes, oils, white-, bread, crispbread and rice. Conclusion: The validity of the VISA-FFQ was acceptable for intake of milk fat, and there was an overall satisfactory, though variable, reproducibility for intake of several foods and lifestyle factors in the VISA-FFQ.

International audience; An experiment was conducted to evaluate the ability of two spectroscopy methods to distinguish between pasture and preserved-forage cheeses. The reflectance spectra of 308 fresh and freeze-dried samples of cow's milk cheeses were recorded at wavelengths in the range of the visible, using a portable MINOLTA CM-2002 spectrophotometer. The reflectance spectra of the same samples were also measured in near infrared range using a non-portable laboratory monochromator NIRSystem 6500. The proportion of cheeses correctly classified by NIRS and visible spectra was respectively 0.96 and 0.91 for pasture samples, and 0.96 and 0.79 for preserved-forage samples. No significant differences were found when fresh and freeze-dried cheeses were compared. We conclude that NIRS is able to classify cheese samples from different regimes (here, pasture vs. preserved-forage). (c) 2013 Elsevier Ltd. All rights reserved.

International audience; The aim of this study was to determine the effects of supplementing unprotected dietary unsaturated fatty acids (UFAs) from different plant oils on gene expression in the mammary gland of grazing dairy cows. A total of 28 Holstein-Friesian dairy cows in mid-lactation were blocked according to parity, days in milk, milk yield and fat percentage. The cows were then randomly assigned to four UFA sources based on rapeseed, soybean, linseed or a mixture of the three oils for 23 days, after which, all 28 cows were switched to a control diet for an additional 28 days. On the last day of both periods, mammary gland biopsies were taken to study genome-wide differences in gene expression on Affymetrix GeneChip® Bovine Genome Arrays (no. 900493) by ServiceXS (Leiden, The Netherlands). Supplementation with UFAs resulted in increased milk yield but decreased milk fat and protein percentages. Furthermore, the proportion of de novo fatty acids (FAs) in the milk was reduced, whereas that of long-chain FAs increased. Applying a statistical cut-off of false discovery rate of q-values

Multiple demands are placed on farming systems today. Society, national legislation and market forces seek what could be seen as conflicting outcomes from our agricultural systems, e.g. food quality, affordable prices, a healthy environmental, consideration of animal welfare, biodiversity etc., Many of these demands, or desirable outcomes, are interrelated, so reaching one goal may often compromise another and, importantly, pose a risk to the economic viability of the farm. SIMS DAIRY , a farm-scale model, was used to explore this complexity for dairy farm systems. SIMS DAIRY integrates existing approaches to simulate the effect of interactions between farm management, climate and soil characteristics on losses of nitrogen, phosphorus and carbon. The effects on farm profitability and attributes of biodiversity, milk quality, soil quality and animal welfare are also included. SIMS DAIRY can also be used to optimise fertiliser N. In this paper we discuss some limitations and strengths of using SIMS DAIRY compared to other modelling approaches and propose some potential improvements. Using the model we evaluated the sustainability of organic dairy systems compared with conventional dairy farms under non-optimised and optimised fertiliser N use. Model outputs showed for example, that organic dairy systems based on grass-clover swards and maize silage resulted in much smaller total GHG emissions per l of milk and slightly smaller losses of NO 3 leaching and NO x emissions per l of milk compared with the grassland/maize-based conventional systems. These differences were essentially because the conventional systems rely on indirect energy use for ‘fixing’ N compared with biological N fixation for the organic systems. SIMS DAIRY runs also showed some other potential benefits from the organic systems compared with conventional systems in terms of financial performance and soil quality and biodiversity scores. Optimisation of fertiliser N timings and rates showed a considerable scope to reduce the (GHG emissions per l milk too).

International audience; Seven- to 10-month-old calves are the typical production of Galician Blond (GB), the most important bovine local beef breed in Spain. As meat lipid repercussions on human health depend on their fatty acid (FA) profile, this study aimed at analysing the individual FA at weaning and at the end of the feeding finishing period, especially trans and cis 18:1 isomers in total lipids of the Longissimus thoracis muscle in GB male calves. Distribution of main FA in veal lipids was characterized by gas-liquid chromatography (GLC) analysis on a high polar glass capillary column. Total trans and cis 18:1 isomers were purified, from total FA (TFA) methyl esters, by preparative reversed-phase high-performance liquid chromatography, to allow subsequent specific analysis of their different isomers by GLC. Calves stayed with their mothers at pasture for 2 or 5 months in intensive or semi-extensive systems, followed by an indoor feeding period. The weaned (W) group was finished on concentrate and hay, whereas the non-weaned (NW) group was finished on concentrate and hay and it continued suckling until slaughter. The studied effects did not present interactions. The duration of the indoor finishing period hardly had a significant influence on the parameters analysed. Compared to W calves, NW calves had higher proportions (% TFA) of 18:3n-3 (+38%, P < 0.0001), 20:5n-3 (+22%, P = 0.005), 22:5n-3 (+13%, P = 0.042), cis monounsaturated FA (MUFA; 18%, P = 0.032), total MUFA (18%, P = 0.013), n-3 polyunsaturated FA (PUFA; +25%, P = 0.0001) and conjugated linoleic acid (CLA; +48%, P < 0.0001) to the detriment of 18:0 (-10%, P = 0.002), 18:2n-6 (-25%, P = 0.004) and n-6 PUFA (-20%, P = 0.011). With regard to cis and trans 18:1 isomers, NW calves had higher proportions (% total cis or trans 18:1) of Delta 11trans and Delta 16trans (+25% and +22%, respectively, P < 0.01) and Delta 13 + 14trans (+13%, P < 0.05) and lower proportions of Delta 6 to 8 and Delta 10trans (-28% and 58%, respectively, P < 0.001). NW calves' meat might be more suitable for human health than W calves' meat due to the increase of anti-atherogenous FA such as n-3 PUFA, CLA and 18:1 Delta 11trans.

Despite the fact that the ruminant diet is rich in polyunsaturated fatty acids (PUFA), ruminant products - meat, milk and dairy - contain mainly saturated fatty acids (SFA) because of bacterial lipolysis and subsequent biohydrogenation of ingested PUFA in the rumen. The link between SFA consumption by man and coronary heart disease is well established. In contrast, ruminant products also contain fatty acids that are known to be beneficial to human health, namely conjugated linoleic acids (CLAs). The aims of research in this field have been to understand the microbial ecology of lipolysis and biohydrogenation and to find ways of manipulating ruminal microbes to increase the flow of PUFA and CLA from the rumen into meat and milk. This review describes our present understanding of the microbial ecology of ruminal lipid metabolism, including some apparently anomalous and paradoxical observations, and the status of how the metabolism may be manipulated and the possible consequential effects on other aspects of ruminal digestion. Intuitively, it may appear that inhibiting the ruminal lipase would cause more dietary PUFA to reach the mammary gland. However, lipolysis releases the non-esterified fatty acids that form the substrates for biohydrogenation, but which can, if they accumulate, inhibit the whole process. Thus, increasing lipase activity could be beneficial if the increased release of non-esterified PUFA inhibited the metabolism of CLA. Rumen ciliate protozoa do not carry out biohydrogenation, yet protozoal lipids are much more highly enriched in CLA than bacterial lipids. How could this happen if protozoa do not metabolise PUFA? The answer seems to lie in the ingestion of plant organelles, particularly chloroplasts, and the partial metabolism of the fatty acids by contaminating bacteria. Bacteria related to Butyrivibrio fibrisolvens are by far the most active and numerous biohydrogenating bacteria isolated from the rumen. But do we misunderstand the role of different bacterial species in biohydrogenation because there are uncultivated species that we need to understand and include in the analysis? Manipulation methods include dietary vegetable and fish oils and plant-derived chemicals. Their usefulness, efficacy and possible effects on fatty acid metabolism and on ruminal microorganisms and other areas of their metabolism are described, and areas of opportunity identified.

Conjugated linoleic acid (CLA) exhibits isomer-specific effects on transepithelial calcium (Ca) transport as well as on cell growth in human intestinal-like Caco-2 cells. However, the molecular mechanisms of action are still unclear. Therefore, this study used a transcriptomic approach to help elucidate the molecular mechanisms underlying such isomer-specific effects. Caco-2 cells were treated with 80 µmol/L linoleic acid (control), 80 µmol/L trans-10, cis-12 CLA, or 80 µmol/L cis-9, trans-11 CLA for 12 d. Ca transport was measured radio-isotopically. RNA was isolated from the cells, labeled, and hybridized to the Affymetrix U133 2.0 Plus arrays (n = 3). Data and functional analysis was preformed using Bioconductor. Using a minimum fold-change criterion of 1.6 and a false discovery rate criterion of P-value 0.05, trans-10, cis-12 CLA altered the expression of 918 genes, whereas, cis-9, trans-11 CLA had no effect on gene expression. Gene ontology analysis revealed that trans-10, cis-12 CLA strongly modulated a number of processes inherently related to carcinogenesis, such as cell cycle, cell proliferation, and DNA metabolism. Trans-10, cis-12 CLA, but not cis-9, trans-11 CLA, increased transepithelial Ca transport in Caco-2 cells, which corresponded to changes in molecular mediators of paracellular (including claudin 2 and 4) and transcellular (calbindin D9k and vitamin D receptor) Ca transport. This microarray-based study highlighted a number of gene expression patterns of relevance to 2 important intestinal processes (carcinogenesis and Ca transport), which were modulated by trans-10, cis-12 CLA. These may help our mechanistic understanding of the role of CLA in promoting gut function and health.

Increasing the availability of glucogenic nutrients relative to lipogenic nutrients has been hypothesized to decrease the production of milk fat, to improve the energy balance (EB), and to decrease the incidence and severity of metabolic and reproductive disorders in dairy cows in early lactation. Therefore, our objective was to evaluate the effects of a glucogenic, lipogenic, or mixed diet on EB, plasma metabolites and metabolic hormones, liver triacylglycerides (TAG), and reproductive variables in high-producing dairy cows in early lactation. Cows (n = 114) were randomly assigned to 1 of 3 diets and were fed either a mainly lipogenic diet, a mainly glucogenic diet, or a mixture of both diets (50:50 dry matter basis) from wk 3 before the expected calving date until 9 wk postpartum. Diets were isocaloric (net energy basis) and equal in intestinal digestible protein. Dry matter intake, net energy intake, milk yield, and milk protein percentage did not differ among diets. Milk lactose percentage was less for cows fed the lipogenic diet. Milk fat percentage was less for multiparous cows fed the glucogenic diet compared with cows fed the mixed or lipogenic diet (3.69 vs. 4.02 vs. 4.22 +/- 0.07%, respectively). The calculated EB was less negative for multiparous cows fed the glucogenic diet compared with cows fed the mixed or lipogenic diet [-33 vs. -125 vs. -89 +/- 21 kJ/(kg(0.75) x d), respectively]. Postpartum, the glucogenic diet decreased plasma nonesterified fatty acids, beta-hydroxybutyrate, and liver TAG concentrations and increased insulin concentration in multiparous cows. The glucogenic diet tended to decrease the number of days until first milk progesterone rise in multiparous cows compared with the mixed or lipogenic diet (20.4 vs. 24.4 vs. 26.4 +/- 2.1 d, respectively). Diet had no effect on any of the above-mentioned variables in primiparous cows, except that milk lactose percentage was greater for primiparous cows fed the glucogenic diet. We concluded that the glucogenic diet was effective in improving the calculated EB and decreasing plasma beta-hydroxybutyrate and liver TAG concentrations, suggesting a reduced risk of metabolic disorders in multiparous dairy cows fed a glucogenic diet.

The objective of this study was to investigate the influence of commercially available monoacylglycerol (M), polyglycerol esters (P), and sunflower lecithin (L) on the onset of crystallization of bulk fat as a function of the added concentration. Not only a single type of emulsifier, but also binary and ternary mixtures of M, P, and L were added to the two different “host” fats using a statistically sound mixture design. The obtained mixtures were analyzed for their non-isothermal crystallization behavior by differential scanning calorimetry. If a single type of emulsifier was added, the nucleation was accelerated when adding M or P, while L addition had no significant effect. Furthermore, it was shown that the minimum concentration necessary to provoke a nucleation accelerating effect is lower for P than for M. Antagonistic effects between M and L (and not between P and L) were suggested by the coefficient estimates of the special cubic model. Practical applications: Palm oil (PO) is one of the most consumed vegetable oils in the world because of its unique physical properties. It imparts a very high stability to the β′ crystal form, yielding relatively small crystals which give a smooth texture to e.g., margarines and shortenings. Because PO is semi-solid at room temperature, it forms an ideal hard stock to be used in trans free food products. However, PO has a slow crystallization rate and an unusually long α-lifetime. These disadvantages can be overcome by the addition of an emulsifier acting as crystallization modifier (e.g., monoacylglycerols and diacylglycerols) [1]. Furthermore, from a nutritional point of view, the saturated fatty acids present in PO [2], are among the factors contributing to cardio-vascular diseases [3]. When using more unsaturated fats as hard stock, the use of additives in order to avoid compromising the functionality of the food product should be further investigated. This study investigated the influence of commercially available monoacylglycerol (M), polyglycerol esters (P), and sunflower lecithin (L) on the onset of crystallization of bulk fat as a function of the added concentration. Not only a single type of emulsifier, but also binary and ternary mixtures of M, P, and L were added to the two different “host” fats using a statistically sound mixture design. The total amount of emulsifiers in each blend was set to 1.5%. The obtained mixtures were analyzed for their non-isothermal crystallization behavior by differential scanning calorimetry. It was shown that the effect on the onset of crystallization of the bulk fat depends on the type and the concentration of emulsifier.

Stearoyl-CoA desaturase (SCD) in the bovine mammary gland introduces a cis-double bond at the ¿9 position in a wide range of fatty acids (FA). Several long-chain polyunsaturated fatty acids (PUFA) inhibit expression of SCD, but information on the effect of short-chain fatty acids on mammary SCD expression is scarce. We used a bovine mammary cell line (MAC-T) to assess the effect of acetic acid (Ac) and ß-hydroxybutyric acid (BHBA) in comparison with the effect of various long-chain fatty acids on the mRNA expression of the lipogenic enzymes SCD, acetyl-CoA carboxylase (ACACA), fatty acid synthase (FASN) and their associated gene regulatory proteins sterol regulatory element binding transcription factor 1 (SREBF1), insulin-induced gene 1 protein (INSIG1) and peroxisome proliferator-activated receptor alpha (PPARA)and peroxisome proliferator-activated receptor delta (PPARD) by quantitative real-time PCR. MAC-T cells were treated for 12 h without FA additions (CON) or with either 5 mM Ac, 5 mM BHBA, a combination of 5 mM Ac + 5 mM BHBA, 100 µM C16:0, 100 µM C18:0, 100 µM C18:1 cis-9, 100 µM C18:1 trans-11, 100 µM C18:2 cis-9,12 or 100 µM C18:3 cis-9,12,15. Compared with control, mRNA expression of SCD1 was increased by Ac (+61%) and reduced by C18:1 cis-9 (-61%), C18:2 cis-9,12 (-84%) and C18:3 cis-9,12,15 (-88%). In contrast to native bovine mammary gland tissue, MAC-T cells did not express SCD5. Expression of ACACA was increased by Ac (+44%) and reduced by C18:2 cis-9,12 (-48%) and C18:3 cis-9,12,15 (-49%). Compared with control, FASN expression was not significantly affected by the treatments. The mRNA level of SREBF1 was not affected by Ac or BHBA, but was reduced by C18:1 cis-9 (-44%), C18:1 trans-11 (-42%), C18:2 cis-9,12 (-62%) and C18:3 cis-9,12,15 (-68%) compared with control. Expression of INSIG1 was downregulated by C18:0 (-37%), C18:1 cis-9 (-63%), C18:1 trans-11 (-53%), C18:2 cis-9,12 (-81%) and C18:3 cis-9,12,15 (-91%). Both PPARA and PPARD expression were not significantly affected by the treatments. Our results show that Ac upregulated mRNA expression of SCD1 and ACACA in MAC-T cells. The opposite effect of the PUFA C18:2 cis-9,12 and C18:3 cis-9,12,15 on the these genes and the failure of Ac to mimic the PUFA-inhibited SREBF1 and INSIG1 mRNA expression, suggest that Ac can stimulate mammary lipogenesis via a transcriptional regulatory mechanism different from PUFA.

International audience; Forages, through the amount and composition of their fatty acids (FA), and because they represent a major part of ruminant diets, can help improve the nutritional quality of milk and meat. However, no comprehensive dataset is available to estimate fat and FA content and composition of forages. This study used the available data on fat and FA content and composition of forages to (i) compute mean composition values for the main forages, and (ii) estimate the influence of forage conservation, cultivation and harvest conditions on fat and FA content and composition. We report mean values for the main forage species in the form of fresh forage, silage or hay. The main factor influencing fat and FA composition was vegetation stage of forage at harvest (estimated by the month of harvest or regrowth interval). Compared with fresh forage at harvest, wilting or drying forages (especially in bad drying conditions) altered their FA, whereas unwilted silage, the use of ensiling additives and N fertilization had only minor effects. The differences between grass (except corn) and legume species were lower than those induced by vegetation stage and wilting or drying. We gave equations to estimate the effects of these factors and thus refine the estimation of the FA content and composition of the forages. Total FA content and proportion of linolenic acid were positively related to crude protein, and negatively related to fiber content of the forages. (C) 2013 Elsevier B.V. All rights reserved.

Background: Dairy product intake may be inversely associated with risk of type 2 diabetes, but the evidence is inconclusive for total dairy products and sparse for types of dairy products. Objective: The objective was to investigate the prospective association of total dairy products and different dairy subtypes with incidence of diabetes in populations with marked variation of intake of these food groups. Design: A nested case-cohort within 8 European countries of the European Prospective Investigation into Cancer and Nutrition Study (n = 340,234; 3.99 million person-years of follow-up) included a random subcohort (n = 16,835) and incident diabetes cases (n = 12,403). Baseline dairy product intake was assessed by using dietary questionnaires. Country-specific Prentice-weighted Cox regression HRs were calculated and pooled by using a random-effects meta-analysis. Results: Intake of total dairy products was not associated with diabetes (HR for the comparison of the highest with the lowest quintile of total dairy products: 1.01; 95% CI: 0.83, 1.34; P-trend = 0.92) in an analysis adjusted for age, sex, BMI, diabetes risk factors, education, and dietary factors. Of the dairy subtypes, cheese intake tended to have an inverse association with diabetes (HR: 0.88; 95% CI: 0.76, 1.02; P-trend = 0.01), and a higher combined intake of fermented dairy products (cheese, yogurt, and thick fermented milk) was inversely associated with diabetes (HR: 0.88; 95% CI: 0.78, 0.99; P-trend = 0.02) in adjusted analyses that compared extreme quintiles. Conclusions: This large prospective study found no association between total dairy product intake and diabetes risk. An inverse association of cheese intake and combined fermented dairy product intake with diabetes is suggested, which merits further study.

Kay-Tee Khaw and colleagues analyze data from a prospective cohort study and show associations between plasma concentrations of saturated phospholipid fatty acids and risk of coronary heart disease, and an inverse association between omega-6 polyunsaturated phospholipid fatty acids and risk of coronary heart disease., Background The lack of association found in several cohort studies between dietary saturated fat and coronary heart disease (CHD) risk has renewed debate over the link between dietary fats and CHD. Methods and Findings We assessed the relationship between plasma phospholipid fatty acid (PFA) concentration and incident CHD using a nested case control design within a prospective study (EPIC-Norfolk) of 25,639 individuals aged 40–79 years examined in 1993–1997 and followed up to 2009. Plasma PFA concentrations were measured by gas chromatography in baseline samples retrieved from frozen storage. In 2,424 men and women with incident CHD compared with 4,930 controls alive and free of cardiovascular disease, mean follow-up 13 years, saturated PFA (14:0, 16:0,18:0) plasma concentrations were significantly associated with increased CHD risk (odds ratio [OR] 1.75, 95% CI 1.27–2.41, p, Editors' Summary Background Coronary heart disease (CHD) is a condition caused by a build-up of fatty deposits on the inner walls of the blood vessels that supply the heart, causing the affected person to experience pain, usually on exertion (angina). A complete occlusion of the vessel by deposits causes a heart attack (myocardial infarction). Lifestyle factors, such as diet (particularly one high in fat), contribute to causing CHD. There are different types of fat, some of which are thought to increase risk of CHD, such as saturated fat, typically found in meat and dairy foods. However, others, such as unsaturated fats (polyunsaturated and monounsaturated fats) found in foods such as vegetable oils, fish, and nuts, may actually help prevent this condition. Why Was This Study Done? Although there have been many studies investigating the role of different types of dietary fat in coronary heart disease, it is still not clear whether coronary heart disease can be prevented by changing the type of dietary fat consumed from saturated to unsaturated fats or by lowering all types of dietary fat. Furthermore, many of these studies have relied on participants recalling their dietary intake in questionnaires, which is an unreliable method for different fats. So in this study, the researchers used an established UK cohort to measure the levels of different types of fatty acids in blood to investigate whether a diet high in saturated fatty acids and low in unsaturated fatty acids increases CHD risk. What Did the Researchers Do and Find? The researchers used a selection of 10,000 participants (all men and women aged 40–79 years) from the prospective European Prospective Investigation into Cancer (EPIC)-Norfolk cohort. Blood samples from the selected participants taken at the start of the study in 1993–1997 were analyzed to determine levels of specific fatty acids. Participants were followed up till 2011. The researchers identified 2,424 participants who were subsequently diagnosed with CHD using death certificates and hospital discharge data and matched these with 4,930 controls who were still alive and free of known coronary disease. The researchers grouped the type of blood fatty acids identified in the blood samples into six families (even chain saturated fatty acid, odd chain saturated fatty acid, omega-6 polyunsaturated fatty acid, omega-3 polyunsaturated fatty acid, monounsaturated fatty acid, and trans-fatty acid), which represented saturated and unsaturated fatty acids. Using statistical methods, the researchers then compared the risks of developing CHD between cases and controls by the concentration of fatty acid families after adjusting for age and sex and other factors, such as body mass index, physical activity, and smoking. Using these methods, the researchers found that there was no overall significant relationship between total blood fatty acid concentration and CHD but there was a positive association with increasing blood saturated fatty acid concentration after adjusting for other fatty acid concentrations, with an odds ratio of 1.83 comparing higher versus lower concentrations. This risk was attenuated after adjusting for cholesterol levels, indicating that much of the association between saturated fatty acid and CHD is likely to be mediated through blood cholesterol levels. In contrast, blood omega-6 poly-unsaturated fatty acid concentrations were associated with lower CHD risk. Blood monounsaturated fatty acids, omega-3 poly-unsaturated fatty acids, and trans-fatty acids were not consistently associated with CHD risk. The authors also noted that within families of fatty acids, individual fatty acids related differently to CHD risk. What Do These Findings Mean? These findings suggest that plasma concentrations of saturated fatty acids are associated with increased risk of CHD and that concentrations of omega-6 poly-unsaturated fatty acids are associated with decreased risk of CHD. These findings are consistent with other studies and with current dietary advice for preventing CHD, which encourages substituting foods high in saturated fat with n-6 polyunsaturated fats. The results also suggest that different fatty acids may relate differently to CHD risk and that the overall balance between different fatty acids is important. However, there are limitations to this study, such as that factors other than diet (genetic differences in metabolism, for example) may cause changes to blood fatty acid levels so a major question is to identify what factors influence blood fatty acid concentrations. Nevertheless, these findings suggest that individual fatty acids play a role in increasing or decreasing risks of CHD. Additional Information Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001255. Information about the EPIC-Norfolk study is available The American Heart Foundation provides patient-friendly information about different dietary fats as does Medline The British Heart Foundation also provides patient-friendly information on heart conditions

International audience; Research has recently focused on pasture species intake by ruminants due to their influence on animal product quality. A field-applicable method which investigates species intake and selection, was tested on two dairy cow grazing systems: continuous grazing on a highly-biodiverse pasture (C) and rotational grazing on a moderately-diverse sward (R). In addition to the grazed class method, which evaluates the percentage of grazed dry matter (DM) per species according to the residual height of the plant grazed, further measurements were introduced to quantify DM consumption and selection index per species. Six and four representative species were studied in the C and R systems respectively. We found an exponential regression between the presence of a species and its contribution to the cattle's daily intake (P

Rumen biohydrogenation kinetics of C18:3n-3 from several chemically or technologically treated linseed products and docosahexaenoic acid (DHA; C22:6n-3) addition to linseed oil were evaluated in vitro. Linseed products evaluated were linseed oil, crushed linseed, formaldehyde treated crushed linseed, sodium hydroxide/formaldehyde treated crushed linseed, extruded whole linseed (2 processing variants), extruded crushed linseed (2 processing variants), micronized crushed linseed, commercially available extruded linseed, lipid encapsulated linseed oil, and DHA addition to linseed oil. Each product was incubated with rumen liquid using equal amounts of supplemented C18:3n-3 and fermentable substrate (freeze-dried total mixed ration) for 0, 0.5, 1, 2, 4, 6, 12, and 24 h using a batch culture technique. Disappearance of C18:3n-3 was measured to estimate the fractional biohydrogenation rate and lag time according to an exponential model and to calculate effective biohydrogenation of C18:3n-3, assuming a fractional passage rate of 0.060/h. Treatments showed no differences in rumen fermentation parameters, including gas production rate and volatile fatty acid concentration. Technological pretreatment (crushing) followed by chemical treatment applied as formaldehyde of linseed resulted in effective protection of C18:3n-3 against biohydrogenation. Additional chemical pretreatment (sodium hydroxide) before applying formaldehyde treatment did not further improve the effectiveness of protection. Extrusion of whole linseed compared with extrusion of crushed linseed was effective in reducing C18:3n-3 biohydrogenation, whereas the processing variants were not different in C18:3n-3 biohydrogenation. Crushed linseed, micronized crushed linseed, lipid encapsulated linseed oil, and DHA addition to linseed oil did not reduce C18:3n-3 biohydrogenation. Compared with the other treatments, docosahexaenoic acid addition to linseed oil resulted in a comparable trans11, cis15-C18:2 biohydrogenation but a lesser trans10+11-C18:1 biohydrogenation. This suggests that addition of DHA in combination with linseed oil was effective only in inhibiting the last step of biohydrogenation from trans10+11-C18:1 to C18:0.

The aim of the present study was to evaluate the use of beta-cyclodextrin (beta-CD) with pasteurized whole milk in an industrial process after churning the cream for making low cholesterol butter with the purpose of manufacturing commercial reduced cholesterol butter. Fatty acids and chemical gross composition (total fat, lactose, protein and total solids) of the untreated and 0.6% beta-cyclodextrin (beta-CD) treated butter were determined. Gas chromatography of the individual methyl esters fatty acids (saturated, monounsaturated and polyunsaturated acids) showed no significant effect by the addition of P-CD. Cholesterol reduction of the commercial butter was 95.53 +/- 2.81% with a residual content of beta-CD of 0.04 +/- 0.01%. The rest of beta-CD remains in the whey during the churning of the cream and in the skim milk. This process provides a considerable reduction of cholesterol in butter without altering the fatty acid composition of the milk fat.

This study analyzed the effect of propionate (C3) and casein (CN) on whole-body and mammary metabolism of energetic nutrients. Three multiparous Holstein cows fitted with both duodenal and ruminal cannulas were used in 2 replicated Youden squares with 14-d periods. Effects of CN (743 g/d in the duodenum) and C3 (1,042 g/d in the rumen) infusions, either separately or in combination as supplements to a grass silage diet, were tested in a factorial arrangement. The control diet provided 97% of energy and protein requirements. Within each period, blood samples were taken (d 11) from the carotid artery and the right mammary vein to determine net uptake of energetic nutrients. Plasma blood flow was calculated using the Fick principle (based on Phe and Tyr). On d 13, [6,6-(2)H(2)]glucose was infused in the jugular vein to determine whole-body glucose rate of appearance (Ra) based on enrichments in arterial plasma. Both C3 and CN treatments increased whole-body Ra (17% and 13%, respectively) but only CN increased milk (18%) and lactose (14%) yields, suggesting no direct link between whole-body Ra and milk yield. When CN was infused alone, the apparent ratio of conversion of CN carbon into glucose carbon was 0.31 but, when allowance was made for the CN required to support the extra milk protein output, the ratio increased to 0.40, closer to the theoretical ratio (0.48). This may relate to the observed increases in arterial glucagon concentrations for CN alone. Conversely, the apparent conversion of infused C3 carbon alone to glucose was low (0.31). With C3, mammary plasma flow increased as did uptakes of lactate, Ala, and Glu whereas the uptake for beta-hydroxybutyrate (BHBA) decreased. Mammary net carbon balance suggested an increase with C3 treatment in glucose, lactate, Ala, and Glu oxidation within the mammary gland. Mammary glucose uptake did not increase with CN treatment, despite an increase in glucose arteriovenous difference and extraction rate, because plasma flow decreased (-17%). Whereas CN, alone or in combination with C3, increased both lactose and protein yields, only mammary AA (and BHBA in CN alone) uptake increased because plasma flow decreased (-17%). These data suggest that the observed variations of milk lactose yield (and other milk components) are linked to metabolic interchanges between several energetic nutrients at both the whole-body and mammary levels and are not explained by increases in whole-body glucose availability.

International audience; Visible-near-infrared reflectance spectroscopy was used to predict the fatty acid (FA) composition of 445 cows' and goats' fresh and freeze-dried cheeses. The FA composition of samples was analysed by reference method. Samples were scanned (400-2500 nm) and predictive equations were developed using modified partial least squares with both cross-validation and external validation. The coefficient of determination in external validation ((RV)-V-2) and residual predictive deviation in the validation set (RPDV) were good for total saturated (0.89, 2.84), monounsaturated (0.90, 2.90), polyunsaturated (0.88, 2.54), trans (0.92, 3.24) FA, butyric (0.84, 2.43), capric (0.92, 2.96), myristic (0.89, 2.94), palmitic (0.91, 3.32), vaccenic (0.88, 2.63), and rumenic (0.90, 2.70) acids in fresh cheeses. Approximate or poor predictions were obtained for caproic, caprylic, lauric, stearic, oleic, linoleic, and linolenic acids ((RV)-V-2

Lactones are fat-derived aroma compounds, but the formation mechanism of these compounds during ripening of Gouda cheese is unknown. Both enzymatic and chemical formation pathways were investigated in this study. Lactone formation from milk triglycerides or free fatty acids by lactic acid bacteria enzymatic activity was not observed. Instead, the mechanism of the lactone formation in cheese was a one-step, non-enzymatic reaction, where a hydroxy fatty acid, esterified in a triglyceride undergoes trans-esterification to release the lactone directly. The lactone reaction potential was determined for all major γ- and δ-lactones by controlled heating of the fat. The chemical formation of lactones was temperature-dependent and the Arrhenius parameters of the formation reaction were estimated for each of the lactones. The kinetics of the reaction were first-order, and could be used to explain the formation of lactones in ripening Gouda cheese up to about 40 weeks.

Conjugated linoleic acid (CLA) exhibits isomer-specific effects on transepithelial calcium (Ca) transport as well as on cell growth in human intestinal-like Caco-2 cells. However, the molecular mechanisms of action are still unclear. Therefore, this study used a transcriptomic approach to help elucidate the molecular mechanisms underlying such isomer-specific effects. Caco-2 cells were treated with 80 µmol/L linoleic acid (control), 80 µmol/L trans-10, cis-12 CLA, or 80 µmol/L cis-9, trans-11 CLA for 12 d. Ca transport was measured radio-isotopically. RNA was isolated from the cells, labeled, and hybridized to the Affymetrix U133 2.0 Plus arrays (n = 3). Data and functional analysis was preformed using Bioconductor. Using a minimum fold-change criterion of 1.6 and a false discovery rate criterion of P-value 0.05, trans-10, cis-12 CLA altered the expression of 918 genes, whereas, cis-9, trans-11 CLA had no effect on gene expression. Gene ontology analysis revealed that trans-10, cis-12 CLA strongly modulated a number of processes inherently related to carcinogenesis, such as cell cycle, cell proliferation, and DNA metabolism. Trans-10, cis-12 CLA, but not cis-9, trans-11 CLA, increased transepithelial Ca transport in Caco-2 cells, which corresponded to changes in molecular mediators of paracellular (including claudin 2 and 4) and transcellular (calbindin D9k and vitamin D receptor) Ca transport. This microarray-based study highlighted a number of gene expression patterns of relevance to 2 important intestinal processes (carcinogenesis and Ca transport), which were modulated by trans-10, cis-12 CLA. These may help our mechanistic understanding of the role of CLA in promoting gut function and health.

International audience

The purpose of this research was to evaluate the texture of regular (12%), low fat (6%), and fat-free vanilla (0.5%) ice creams by sensory and instrumental analyses. The low fat and fat free ice cream were prepared using a whey protein based fat replacer (Simplesse (R) 100) as the fat replacement ingredient. Two processing trials with continuous commercial-like process conditions were undertaken. Sensory analyses disclosed that ice creams containing 6% of fat replacer in place of or with milk fat had no demonstrable effect on vanillin flavour. While the sensory attributes of the low fat samples were comparable to the regular vanilla ice cream, the trained sensory panel rated the fat free ice cream to have lower viscosity, smoothness and mouth coating properties. Instrumentally determined apparent viscosity data supported the sensory data. Compared with the fat replacer, milk fat significantly increased the fresh milk and cream flavours of the ice cream. Results emphasized the importance of fat as a flavour modifier and the improvement of texture by addition of Simplesse (R) 100.

Cis 9, trans 11 (c9, t11)-18:2 and trans 10, cis 12 (t10, c12)-18:2 are the major conjugated linoleic acid (CLA) isomers in dietary supplements which reduce milk fat content in nursing women. The present study evaluated the effects of each CLA isomer or vaccenic acid on body composition and tissue fatty acids during lactation in mice. Dams were fed 30 g rapeseed oil (control)/kg diet or 20 g control plus 10 g 18: 0, trans 11-18: 1 (t11-18 : 1), c 9, t1 1-18: 2, or t10, c12-18: 2. Dietary t10, c12-18: 2 reduced food intake by 18 % and carcass fat weight of the dams by 49 % compared with the other treatments. Milk fat percentage ranked by treatment was 18: 0 > t1 1-18: 1 = c 9, t11-18:2 > t10, c12-18:2. The sum of saturated 12:0 to 16:0 in milk fat was lower when c9, t11-18:2 was fed compared with the control, 18:0, or t11-18: 1 treatments. Dietary t10, c12-18:2 caused further reductions in milk fat 12:0 to 16:0. The proportion of CLA isomers was 3-fold greater in milk fat than in the carcasses of the dams. The pups nursing from the dams fed t10, c12-18:2 had the lowest body weights and carcass fat, protein, and ash contents. Nursing from the dams fed c9, t1 l-18:2 also resulted in lower carcass fat compared with the 18:0 or t1 l-18 : 1 treatments. The ratios of cis 9-16: 1:16:0 or cis 9-18: 1:18:0, proxies for Delta(9)-desaturase activity, were markedly lower in the carcasses of the dams and pups fed t10, c12-18: 2. The ratio of 20: 4n-6:18: 2n-6, a proxy for Delta(6)- and Delta(5)-desaturase and elongase activity, in the liver of the dams and pups fed t10, c12-18: 2 also was lower. Dietary t1 l-18 : 1 enhanced the content of c9, t1 l-18 : 2 in milk fat and carcasses. As in previous studies, the reduction in food intake by t10, c12-18: 2 could not entirely account for the marked decrease in carcass fat content and milk fat concentration. T10, c12-18: 2 probably had a negative effect on Delta(9)-desaturase and mammary de novo fatty acid synthesis. Although these effects need to be confirmed in lactating women, the results suggest that the consumption of supplements containing t10, c12-18: 2 should be avoided during the nursing period.