Health benefits of conjugated linoleic acid (CLA)

Bioconversion of conjugated linoleic acid by Lactobacillus plantarum CGMCC8198 supplemented with Acer truncatum bunge seeds oil

Conjugated linoleic acid (CLA) isomers, c9, t11-CLA and t10, c12-CLA, have been proved to exhibit excellent biomedical properties for potential use in anti-cancer applications and in reducing obesity. Acer truncatum Bunge (ATB), which is rich in unsaturated fatty acids, including oleic acid, linoleic acid, and nervonic acid, is a new resource for edible oil. In the present study, we developed a new method for producing two CLA isomers from ATB-seed oil by fermentation using Lactobacillus plantarum CGMCC8198 (LP8198), a novel probiotics strain. Polymerase chain reaction results showed that there was a conserved linoleate isomerase (LIase) gene in LP8198, and its transcription could be induced by ATB-seed oil. Analyses by gas chromatography-mass spectrometry showed that the concentration of c9, t11-CLA and t10, c12-CLA in ATB-seed oil could be increased by about 9- and 2.25-fold, respectively, after being fermented by LP8198.

Fatty Acid Profiles of In Vitro Digested Processed Milk

Digestion of milkfat releases some long-chain (18-carbon) fatty acids (FAs) that can provide health benefits to the consumer, yet because they are found in small amounts and can be difficult to identify, there is limited information on the effects that common fluid milk processing may have on the digestibility of these FAs. This study provides FA profiles for raw and combinations of homogenized and/or heat-treated (high and ultra-high temperature pasteurization) milk, before and after in vitro digestion, in order to determine the effects of processing on the digestibility of these healthy fatty acids. Use of a highly sensitive separation column resulted in improved FA profiles that showed that, when milk was subjected to both pasteurization and homogenization, the release of the 18-carbon FAs, oleic acid, linoleic acid (an omega-6 FA), rumenic acid (a conjugated linoleic acid, CLA), and linolenic acid (an omega-3 FA) tended to be higher than with either pasteurization or homogenization, or with no treatment. Milk is noted for containing the omega-3 FAs and CLAs, which are associated with positive health benefits. Determining how processing factors may impact the components in milk will aid in understanding the release of healthy FAs when milk and dairy foods are consumed.

Application of Response Surface Methodology to Study the Effects of Brisket Fat, Soy Protein Isolate, and Cornstarch on Nutritional and Textural Properties of Rabbit Sausages

The effects of brisket fat, soy protein isolate, and cornstarch on chemical and textural properties of rabbit sausages were studied using surface response methodology. Sausage samples were prepared using a five-level three-variable Central Composite Rotatable Design with 16 combinations, including two replicates of the center point, carried out in random order. The level of brisket fat (BF), soy protein isolate (SPI), and cornstarch (CS) in the sausage formulation ranged within 8.3–16.7%, 0.7–2.3%, and 1.3–4.7%, respectively. Increasing BF decreased moisture and ash contents but increased protein and fat contents of the sausages (p < 0.05). Increasing SPI increased moisture content but decreased ash and carbohydrate contents of the sausages (p < 0.05). Increasing CS increased carbohydrate content (p < 0.05). Increasing BF increased hardness, adhesiveness, cohesiveness, and chewiness but decreased springiness (p < 0.05). SPI addition increased springiness but decreased adhesiveness, cohesiveness, and chewiness (p < 0.05). In conclusion, varying the levels of BF and SPI had a more significant effect on chemical and textural properties of rabbit sausages than CS.

Factors affecting human colostrum fatty acid profile: A case study

The role of maternal colostrum to infant development has been extensively studied and presented. Among the main factors which contribute to breast milk composition are maternal diet, age and body mass index, parity, duration of pregnancy and stage of lactation. This study aims to investigate the potential impact of several factors including demographic (i.e. maternal age and nationality) on the colostrum fatty acid profile. Colostrum was collected the third day postpartum in a Greek maternity hospital. Certain lipid quality indices and fatty acid ratios were estimated and results were statistically processed. The main identified fatty acids were palmitic (C16:0), oleic (C18:1ω-9), and linoleic (C18:2ω-6) acids. Among fatty acids, saturated fatty acids predominated (47.61%), followed by monounsaturated fatty acids (39.26%), while polyunsaturated fatty acids had the lowest proportion (13.13%). Values of lipid quality indices were within the reported in the literature ranges. Maternal body mass index, nationality, age, mode of delivery, gender and fetal weight percentile were studied in respect to their potential influence on the fatty acid profile of colostrum fat. Results suggest that colostrum fatty acid profile was mainly dependent on maternal nationality and age rather than mode of delivery and maternal BMI. Regarding the effect of maternal nationality, significant differences were found for saturated and monounsaturated fatty acids. Of the most interesting findings is that colostrum fat from older (≥35 years) mothers had less saturated fat and more appropriate LQIs values. Finally, a reversed correlation was observed between the customized centile of the infants and the colostrum fat content.

Revealing ruthenium and basicity synergetic effects in Ru–MgAl catalysts for isomerization of linoleic acid to conjugated linoleic acid

Ru–MgAl catalysts were prepared by co-precipitation at different pH values, with the aim of investigating their catalytic performance for isomerization of linoleic acid and of understanding the relationship of basicity site and Ru activity site.

Quality characteristics, chemical composition, and sensory properties of butter from cows on pasture versus indoor feeding systems

This study evaluated the effects of 3 widely practiced cow feeding systems in the United States, Europe, and Southern Hemisphere regions on the characteristics, quality, and consumer perception of sweet cream butter. Fifty-four multiparous and primiparous Friesian cows were divided into 3 groups (n=18) for an entire lactation. Group 1 was housed indoors and fed a total mixed ration diet (TMR) of grass silage, maize silage, and concentrates; group 2 was maintained outdoors on perennial ryegrass-only pasture (GRS); and group 3 was maintained outdoors on a perennial ryegrass/white clover pasture (CLV). Mid-lactation butter was manufactured in triplicate with milk from each group in June 2015 (137±7d in milk) and was analyzed over a 6-mo storage period at 5°C for textural and thermal properties, fatty acid composition, sensory properties, and volatile compounds. The nutritional value of butters was improved by pasture feeding, and butter from pasture-fed cows had significantly lower thrombogenicity index scores compared with butters from TMR-fed cows. In line with these results, pasture-derived milks (GRS and CLV) produced butter with significantly higher concentrations of conjugated linoleic acid (cis-9,trans-11) and trans-β-carotene than TMR butter. Alterations in the fatty acid composition of butter contributed to significant differences in textural and thermal properties of the butters. Total mixed ration-derived butters had significantly higher hardness scores at room temperature than those of GRS and CLV. Onset of crystallization for TMR butters also occurred at significantly higher temperatures compared with pasture butters. Volatile analysis of butter by gas chromatography-mass spectrometry identified 25 compounds present in each of the butters, 5 of which differed significantly based on feeding system, including acetone, 2-butanone, 1-pentenol, toluene, and β-pinene. Toluene was very significantly correlated with pasture-derived butter. Sensory analysis revealed significantly higher scores for GRS-derived butter in several attributes including "liking" of appearance, flavor, and color over those of TMR butter. Partial least square regression plots of fatty acid profiles showed clear separation of butter derived from grazed pasture-based perennial ryegrass or perennial rye/white clover diets from that of a TMR system, offering further insight into the ability of fatty acid profiling to verify such pasture-derived dairy products.

Effect of pasture versus indoor feeding systems on raw milk composition and quality over an entire lactation

The aim of this study was to investigate the effects of different feeding systems on milk quality and composition. Fifty-four multiparous and primiparous Friesian lactating cows were divided into 3 groups (n=18) to study the effects of 3 feeding systems over a full lactation. Group 1 was housed indoors and offered a total mixed ration diet (TMR), group 2 was maintained outdoors on a perennial ryegrass pasture (referred to as grass), and group 3 was also grazed outdoors on a perennial ryegrass/white clover pasture (referred to as clover). Bulk milk samples were collected from each group at morning and afternoon milkings once weekly from March 11 to October 28 in 2015. Milk from pasture-fed cows (grass and clover) had significantly higher concentrations of fat, protein, true protein, and casein. The pasture feeding systems induced significantly higher concentrations of saturated fatty acids C11:0, C13:0, C15:0, C17:0, C23:0, and unsaturated fatty acids C18:2n-6 trans, C18:3n-3, C20:1, and C20:4n-6 and a greater than 2-fold increase in the conjugated linoleic acid C18:2 cis-9,trans-11 content of milk compared with that of the TMR feeding system. The TMR feeding system resulted in milks with increased concentrations of C16:0, C18:2n-6 cis, C18:3n-6 cis, C22:0 C22:1n-9, and C18:2 cis-10,trans-12. Principal component analysis of average fatty acid profiles showed clear separation of milks from the grazed pasture-based diets to that of a TMR system throughout lactation, offering further insight into the ability to verify pasture-derived milk by fatty acid profiling.

Incorporation and effects of punicic acid on muscle and adipose tissues of rats

BACKGROUND

This study evaluated the effect of pomegranate seed oil (PSO) supplementation, rich in punicic acid (55 %/C18:3-9c,11 t,13c/CLNA), on the lipid profile and on the biochemical and oxidative parameters in the gastrocnemius muscle and adipose tissues of healthy rats. Linseed oil (LO), rich in linolenic acid (52 %/C18:3-9c12c15c/LNA) was used for comparison.

METHODS

Male Wistar rats (n = 56) were distributed in seven groups: control (water); LNA 1 %, 2 % and 4 % (treated with LO); CLNA 1 %, 2 % and 4 % (treated with PSO), po for 40 days. The percentages were compared to the daily feed intake. Fatty acid profile were performed by gas chromatography, antioxidant enzymes activity by spectrophotometer and the adipocytes were isolated by collagenase tissue digestion. Analysis of variance (ANOVA) was applied to check for differences between the groups (control, LNAs and CLNAs) and principal component analysis (PCA) was used to project the groups in the factor-place (PC1 vs PC2) based on the biochemical responses assessed in the study.

RESULTS

The fatty acids profile of tissues showed that the LNA percentages were higher in the animals that were fed LO. However, PA was only detected in the adipose tissues. Conjugated linoleic acid (CLA) was present in all the tissues of the animals supplemented with PSO, in a dose dependent manner, and 9c11t-CLA was the predominant isomer. Nevertheless there were no changes in the total weight gain of the animals, the weights of the tissues, and the oxidative stress parameters in the muscle. In addition, there was an increase in the size of the epididymal fat cells in the groups treated with PSO. Principal component analysis (PCA) showed that the CLNAs groups were arranged separately with a cumulative variance of 68.47 %.

CONCLUSIONS

The results show that PSO can be used as a source of CLAs but that it does not cause changes in body modulation and does not interfere in the antioxidant activity of healthy rats.

Short communication: A nanoemulsified form of oil blends positively affects the fatty acid proportion in ruminal batch cultures

Two consecutive rumen batch cultures were used to study the effect of nanoemulsified oils as a new type of supplement, on the in vitro fatty acid proportion and vaccenic acid formation. Three levels (3, 5, and 7%) of 2 different oil blends [soybean:fish oil (SF) or rapeseed-fish oil (RF)] were used. Both oil blends were used either in the raw form (SF or RF, respectively) or in the nanoemulsified form (NSF or NRF, respectively). The diets were the control (0%), which consisted of a dry total mixed ration without any supplements, the control plus 3, 5, or 7% of the SF or RF oil blend in appropriate form (raw or nanoemulsified). For each treatment, 6 incubation vessels were used. Each batch culture was incubated for 24h and conducted twice in 2 consecutive days. All supplements were calculated as a percentage of the substrate dry matter (400mg). Nanoemulsified supplements were recalculated to make sure the oil amount was equal to the raw oil supplementation levels. The results from both experiments indicated that the proportions of vaccenic acid and cis-9,trans-11 C18:2 increased when a raw oil blend was supplemented; on the other hand, no influence of nanoemulsified form of oil blend was observed on the proportion cis-9,trans-11 C18:2. Generally, supplementation with the nanoemulsified oil blends had less effect on biohydrogenation intermediates than the raw form of oil blends. However, the nanoemulsified form had a greater effect on the increase of n-3 and n-6 fatty acids. Nanoemulsified oil blends had a positive effect on decreasing the transformation rate of polyunsaturated fatty acids to saturated fatty acids in the biohydrogenation environment. Supplements of nanoemulsified oil blends tended to be more effective than supplements of raw oils in preserving a greater proportion of polyunsaturated fatty acids in the fermentation culture.

Exploring the heat-induced structural changes of β-lactoglobulin -linoleic acid complex by fluorescence spectroscopy and molecular modeling techniques

Linoleic acid (LA) is the precursor of bioactive oxidized linoleic acid metabolites and arachidonic acid, therefore is essential for human growth and plays an important role in good health in general. Because of the low water solubility and sensitivity to oxidation, new ways of LA delivery without compromising the sensory attributes of the enriched products are to be identified. The major whey protein, β-lactoglobulin (β-Lg), is a natural carrier for hydrophobic molecules. The thermal induced changes of the β-Lg-LA complex were investigated in the temperature range from 25 to 85 °C using fluorescence spectroscopy techniques in combination with molecular modeling study and the results were compared with those obtained for β-Lg. Experimental results indicated that, regardless of LA binding, the polypeptide chain rearrangements at temperatures higher than 75 °C lead to higher exposure of hydrophobic residues causing the increase of fluorescence intensity. Phase diagram indicated an all or none transition between two conformations. The LA surface involved in the interaction with β-Lg was about 497 Ǻ(2), indicating a good affinity between those two components even at high temperatures. Results obtained in this study provide important details about heat-induced changes in the conformation of β-Lg-LA complex. The thermal treatment at high temperature does not affect the LA binding and carrier functions of β-Lg.