Proportion Of Unsaturated Fatty Acids Research Articles

Exploring cellular fatty acid composition and intracellular metabolites of osmotic-tolerant mutant Lactobacillus paracasei NCBIO-M2 for highly efficient lactic acid production with high initial glucose concentration

High titer, productivity and yield are the main pre-requisites of an efficient lactic acid production process. However, the hyperosmotic stress inhibits cell metabolism in the later phase of fermentation. In this study, an osmotic-tolerant mutant named Lactobacillus paracasei NCBIO01-M2 was obtained through a high-throughput screening technology, which exhibited a higher tolerance to osmotic stress due to its more flexible regulation of the unsaturated fatty acid proportion along with the intracellular compatible solute pools. The mutant successfully consumed all 248 g/L initial glucose and produced 223.7 g/L lactic acid with a productivity of 5.53 g/L/h in a single batch fermentation by the neutralizing agent strategy. Moreover, similar fermentation performances were also achieved in the open fermentation mode without sterilization by the mutant, which suggested that the mutant would be a potential for cost-effective commercial lactic acid production.

Effect of barrel temperature and moisture content on the composition and oxidative stability of extruded palm oil in an oil-starch model system

This study aimed to evaluate changes in the fatty acid composition, oxidative stability and contents of some functional groups of palm oil (PO) during extrusion with corn starch or potato starch under two different extrusion conditions. The contents of saturated fatty acids in extracted PO ranged from 48.5 to 53.06 g/100 g of total fatty acids and were higher than that in unprocessed PO, while the proportions of unsaturated fatty acids were reduced after extrusion. Compared with extrusion at 100 °C with 22 g/100 g moisture content, extrusion at 160 °C with 16 g/100 g moisture content yielded peroxide values, conjugated diene values and p-anisidine values that were greater for extruded PO by ∼1-fold, ∼1-fold and ∼5-fold, respectively, regardless of the type of starch. Moreover, PO extruded with potato starch showed a better oxidative stability than PO extruded with corn starch. Alterations in the O-H, cis C=C, trans C=C and C=O contents in extruded PO were measured by the FTIR-based method. These results showed that extrusion conditions and the type of starch affect the quality of extruded lipids and can be used to choose a formula, determine the extrusion processing parameters and devise the package of oil-containing extruded food products.

Viability and membrane lipid composition under a 57 mT static magnetic field in Salmonella Hadar

The aim of this work is to demonstrate the effects of a static magnetic field (SMF) with an induction 12 equal to 57mT on the viability and membrane lipid composition of Salmonella Hadar. Results showed an increase in the viability of exposed bacteria compared to controls after 9h of exposure. Analysis with gas chromatography of total lipids (TLs) and different fractions of phospholipids: phosphatidylglycerols (PGs), phosphatidylethanolamines (PEs), and cardiolipins (CLs), separated by thin layer chromatography revealed changes in fatty acid levels during exposure. For TLs, the unsaturated fatty acids/saturated fatty acids ratio (UFAs/SFAs) had significantly increased after 9 h of exposure. The variation of this ratio seems to be essentially due to the increase of the proportion of unsaturated fatty acids with 18 carbons, in particular C18:1. The analyses of fatty acid composition carried out on the scale of each fraction of phospholipids showed that CLs contributed significantly to the increase of the proportion of the unsaturated fatty acids between 6 and 9h of exposure thanks to their unsaturated chains with 18 carbons (especially C18:2). CLs appear to be the main phospholipid involved in the adaptation of S. Hadar membranes to the SMF.

Adipokinetic hormone signaling determines dietary fatty acid preference through maintenance of hemolymph fatty acid composition in the cricket Gryllus bimaculatus

Adipokinetic hormone (AKH), an analog of mammalian glucagon, functions in supplying the required energy by releasing lipids and carbohydrates from the fat body into the hemolymph. Our previous study showed that AKH receptor (AKHR) knockdown in the two-spotted cricket Gryllus bimaculatus decreased hemolymph lipid levels and increased its feeding frequency. To reveal underlying mechanisms by which AKH signaling modulates lipid homeostasis, we analyzed the fatty acid composition as the lipid structure in the crickets. AKH administration significantly increased the proportion of unsaturated fatty acids (USFAs) to total fatty acids with decrease of the saturated fatty acids (SFAs) in hemolymph, while these proportions were inversely changed in RNA interference-mediated AKHR-knockdowned (AKHRRNAi) crickets. Interestingly, knockdown of hormone-sensitive lipase (Hsl) by RNAi (HslRNAi) affected the proportion of USFAs and SFAs in a similar manner to that observed in AKHRRNAi crickets. AKH administration in HslRNAi crickets did not change hemolymph fatty acid composition, indicating that AKH signaling critically altered fatty acid composition in the hemolymph through Hsl. In addition, a choice assay revealed that AKHRRNAi significantly increases the preference of USFAs. These data indicate that hemolymph lipid level and composition were modulated by AKH signaling with a complementary feeding behavior toward USFAs.

The effect of sunflower seed oil supplementation on the milk fatty acid contents of cows fed leucaena in an intensive silvopastoral system

Transvaccenic acid (TVA), c9t11 conjugated linoleic acid (CLA), and the proportion of unsaturated fatty acids (FAs) in bovine milk are associated with human health benefits. The effect of nutritional supplementation without (NSO) or with sunflower seed oil (63.3% linoleic acid and 28.3% oleic acid) at 20 g/kg (SO20) of dry matter (DM) and 40 g/kg of DM (SO40) was evaluated in milk cows foraging on Leucaena leucocephala in intensive silvopastoral systems (ISS). Two experiments were performed, the first on a specialized tropical dairy farm (STDF) and the second on a dual-purpose tropical farm (DPTF), where cattle are fed an average of 5.8 kg/d and 2.0 kg/d of concentrate, respectively, in addition to grazing on pasture. Sunflower seed oil supplementation tended to decrease forage intake but did not affect milk yield or the milk protein and lactose percentages in either experiment. The proportion of fat, total solids, and milk urea nitrogen (MUN) decreased with oil supplementation on the STDF. However, on the DPTF, these three variables did not change significantly when SO20 or SO40 were compared to NSO, but the values were higher for SO20 compared to SO40. The proportion of CLAc9t11 and TVA linearly increased with the two levels of supplementation in both experiments. Furthermore, the atherogenic FAs decreased, and the milk had greater amounts of unsaturated FAs (UFAs) and a lower atherogenic index. Supplementing cows under an ISS with sunflower seed oil increases the proportion of beneficial milk FAs. On the STDF oil supplementation produced milk with a lower fat content and a greater proportion of high-quality fatty acids, presenting an interesting possibility for fat restricted diets.

Streptomyces coelicolor strains lacking polyprenol phosphate mannose synthase and protein O-mannosyl transferase are hyper-susceptible to multiple antibiotics.

Polyprenol phosphate mannose (PPM) is a lipid-linked sugar donor used by extra-cytoplasmic glycosyl tranferases in bacteria. PPM is synthesiszed by polyprenol phosphate mannose synthase, Ppm1, and in most Actinobacteria is used as the sugar donor for protein O-mannosyl transferase, Pmt, in protein glycosylation. Ppm1 and Pmt have homologues in yeasts and humans, where they are required for protein O-mannosylation. Actinobacteria also use PPM for lipoglycan biosynthesis. Here we show that ppm1 mutants of Streptomyces coelicolor have increased susceptibility to a number of antibiotics that target cell wall biosynthesis. The pmt mutants also have mildly increased antibiotic susceptibilities, in particular to β-lactams and vancomycin. Despite normal induction of the vancomycin gene cluster, vanSRJKHAX, the pmt and ppm1 mutants remained highly vancomycin sensitive indicating that the mechanism of resistance is blocked post-transcriptionally. Differential RNA expression analysis indicated that catabolic pathways were downregulated and anabolic ones upregulated in the ppm1 mutant compared to the parent or complemented strains. Of note was the increase in expression of fatty acid biosynthetic genes in the ppm1- mutant. A change in lipid composition was confirmed using Raman spectroscopy, which showed that the ppm1- mutant had a greater relative proportion of unsaturated fatty acids compared to the parent or the complemented mutant. Taken together, these data suggest that an inability to synthesize PPM (ppm1) and loss of the glycoproteome (pmt- mutant) can detrimentally affect membrane or cell envelope functions leading to loss of intrinsic and, in the case of vancomycin, acquired antibiotic resistance.

Blood hormones, metabolic parameters and fatty acid proportion in dairy cows fed condensed tannins and oils blend

Abstract The aim of this study was to track the changes in blood parameters of mid-lactation multiparous Polish Holstein-Friesian cows in response to a diet supplemented with a mixture of fish-soybean oils blend and tannin-containing lingonberry shrub (Vaccinium vitis idaea; VVI) extract. Twelve lactating cows were randomly assigned to a crossover design of two treatments (6 cows per treatment) which consisted of a control diet containing no supplement (CON) and CON supplemented with a mixture of 99 g of VVI leaves extract and 660 g of blended fish-soybean oils (MIX) daily. The obtained results showed a significant increase in plasma glucose level, as well as C18:1t11 and n-3 fatty acids proportion. A significant decrease was also observed in insulin concentration, triglyceride and C18:0 proportion. Generally, the saturated fatty acid proportion decreased while the unsaturated fatty acid significantly increased with the MIX diet. In conclusion, using supplements of a mixture of VVI extract and fish-soybean oils blend modulated the unsaturated fatty acid proportion in blood, without affecting the dairy cows’ blood parameters which were all within the normal ranges.

Plant oil supplements reduce methane emissions and improve milk fatty acid composition in dairy cows fed grass silage-based diets without affecting milk yield

Four lipid supplements varying in chain length or degree of unsaturation were examined for their effects on milk yield and composition, ruminal CH4 emissions, rumen fermentation, nutrient utilization, and microbial ecology in lactating dairy cows. Five Nordic Red cows fitted with rumen cannulas were used in a 5 × 5 Latin square with five 28-d periods. Treatments comprised total mixed rations based on grass silage with a forage-to-concentrate ratio of 60:40 supplemented with no lipid (CO) or 50 g/kg of diet dry matter (DM) of myristic acid (MA), rapeseed oil (RO), safflower oil (SO), or linseed oil (LO). Feeding MA resulted in the lowest DM intake, and feeding RO reduced DM intake compared with CO. Feeding MA reduced the yields of milk, milk constituents, and energy-corrected milk. Plant oils did not influence yields of milk and milk constituents, but reduced milk protein content compared with CO. Treatments had no effect on rumen fermentation characteristics, other than an increase in ammonia-N concentration due to feeding MA, RO, and SO compared with CO. Lipid supplements reduced daily ruminal CH4 emission; however, the response was to some extent a result of lower feed intake. Lipids modified microbial community structure without affecting total counts of bacteria, archaea, and ciliate protozoa. Dietary treatments had no effect on the apparent total tract digestibility of organic matter, fiber, and gross energy. Treatments did not affect either energy secreted in milk as a proportion of energy intake or efficiency of dietary N utilization. All lipids lowered de novo fatty acid synthesis in the mammary gland. Plant oils increased proportions of milk fat 18:0, cis 18:1, trans and monounsaturated fatty acids, and decreased saturated fatty acids compared with CO and MA. Both SO and LO increased the proportion of total polyunsaturated fatty acids, total conjugated linolenic acid, and cis-9,trans-11 conjugated linoleic acid. Feeding MA clearly increased the Δ9 desaturation of fatty acids. Our results provide compelling evidence that plant oils supplemented to a grass silage-based diet reduce ruminal CH4 emission and milk saturated fatty acids, and increase the proportion of unsaturated fatty acids and total conjugated linoleic acid while not interfering with digestibility, rumen fermentation, rumen microbial quantities, or milk production.

Dietary Alfalfa and Calcium Salts of Long-Chain Fatty Acids Alter Protein Utilization, Microbial Populations, and Plasma Fatty Acid Profile in Holstein Freemartin Heifers.

This study presented the effects of alfalfa and calcium salts of long-chain fatty acids (CSFA) on feed intake, apparent digestibility, rumen fermentation, microbial community, plasma biochemical parameters, and fatty acid profile in Holstein freemartin heifers. Eight Holstein freemartin heifers were randomly divided into a 4 × 4 Latin Square experiment with 2 × 2 factorial diets, with or without alfalfa or CSFA. Dietary supplementation of CSFA significantly increased the apparent digestibility of dry matter, crude protein, neutral detergent fiber, organic matter, and significantly reduced N retention (P < 0.05). CSFA increased the concentration of ammonia nitrogen in the ruminal fluid (P < 0.05), but alfalfa increased the concentration of valerate and isovalerate (P < 0.05). CSFA increased the concentration of ammonia nitrogen and the relative population of Streptococcus bovis in the rumen (P < 0.05) and inhibited the relative population of Ruminococcus flavefaciens, methanogens, and protozoa (P < 0.05). Alfalfa instead of Leymus chinensis increased the relative population of Butyrivibrio fibrisolvens and Ruminobacter amylophilus in the rumen (P < 0.05) and reduced the relative population of the Ruminococcus albus and Megasphaera elsdenii (P < 0.05). Supplemental CSFA increased the concentration of cholesterol and low-density lipoprotein cholesterol in the plasma (P < 0.05). And it also altered the composition of fatty acids in the plasma, which was expressed in reducing saturated fatty acid (ΣSFA) ratio and C14-C17 fatty acids proportion except C16:0 (P < 0.05) and increasing the proportion of polyunsaturated fatty acid (ΣPUFA) and unsaturated fatty acid (ΣUFA) (P < 0.05). The results showed that alfalfa and CSFA had interaction effect on the apparent digestibility of ether extracts, plasma triglyceride concentration, isobutyrate concentration, and Ruminococcus albus relative abundance in the rumen. It was concluded that alfalfa substituting Leymus chinensis did not change the apparent digestibility of nutrients in the final stage of fattening Holstein freemartin heifers, while CSFA increased the cholesterol and the proportion of unsaturated fatty acids in plasma. Alfalfa and CSFA had mutual interaction effect on fat digestion and plasma triglycerides.

Effect of additives on fatty acid profile of high moisture alfalfa silage during ensiling and after exposure to air

The objective of present study was to investigate the changes of total fatty acid (FA) content and fatty acid composition in high moisture alfalfa (DM=229g/kg fresh weight) silage treated without (Control) or with Lactobacillus buchneri (LB), L. plantarum (LP), propionic acid additive (PA) and tea polyphenols (TP) during ensiling and after exposure to air. A 750g of alfalfa material was filled into the experimental silo (polyvinyl chloride bottle, 1000mL capacity). After ensiling for 65days at room temperature, a part of silages (200g) was sampled and the others (450g) were exposed to air for 6days. Butyric acid (>30g/kg DM) was more than lactic acid (<1g/kg DM) in the control and TP silages due to the low contents of DM and water-soluble carbohydrates, and high buffer capacity, indicating poor fermentation quality. LB, LP, and PA promoted lactic fermentation, restrained butyric fermentation and thus improved fermentation quality of silages. Unsaturated fatty acids (UFA) lipolysis and saturated fatty acids (SFA) synthesis occurred in the control silage during ensiling, mainly the lipolysis of C18:2n-6 and C18:3n-3 and synthesis of C6:0. Compared with the control, LB, LP, and PA restrained butyric fermentation and synthesis of C6:0, meanwhile LB and LP did not relieve the lipolysis of UFA while PA relieved it; TP relieved synthesis of C6:0 and had a slight lipolysis of UFA. After exposure to air for 6days, the control, LB, PA, and TP silages had better aerobic stability than LP silage, supported by higher temperature in LP silage than in the control, LB, PA, and TP silages. Like volatile FA, most of the FA composition had a positive correlation with aerobic stability. PA silage had the highest total FA content (33.8g/kg DM), the proportions of UFA, C18:2n6 and C18:3n3 due to its lower pH (<4.60) and amounts of aerobic bacteria (<5.0lgcfu/g FM) and yeasts (<2.6lgcfu/g FM) than the control, LB and LP silages, and its lower pH and aerobic bacteria number than TP silage. Therefore, PA kept silage aerobic stability and was a good additive to conserve FA of silage after exposure to air for 6days.

Snail as mini-livestock: Nutritional potential of farmed Pomacea canaliculata (Ampullariidae)

Amino acids, fatty acids and minerals were investigated in the farmed freshwater snail Pomacea canaliculata (Ampullariidae) to understand its nutritional potential as alternative livestock. Snail samples with removed gut content were collected from a local snail farm in the Republic of Korea. Almost all the essential amino acids present in the snail protein satisfied the recommended level for an ideal protein pattern, while methionine was present at a marginal level. The proportion of unsaturated fatty acids (60.5%) was higher than that of saturated fatty acids (39.5%). The ratio of polyunsaturated to monounsaturated fatty acids was 1.08, underscoring the high nutritional quality of the fat content of the species. The most abundant mineral was calcium. The high K/Na ratio (3.9) and the presence of substantial amounts of phosphorus, iron and zinc makes P. canaliculata snail meat potentially valuable. Thus, the utilization of under-appreciated nutritious food resources could be helpful in mitigating food security problems and in solving nutritional shortcomings in underprivileged parts of the world.

Degradation of Edible Oil During Deep‐Frying Process by Electron Spin Resonance Spectroscopy and Physicochemical Appreciation

During frying process of edible oil, lipid oxidation occurs, which is a complex process and involves free radical chain reactions. The impacts of oil with different fatty acid composition on free radicals were evaluated. An ESR study was performed to identify and quantify the formed radicals, along with the assessment of physicochemical parameters including peroxide value, oxidative stability, fatty acid composition, and volatile profile. Results showed an increase of formed free radicals in frying oils over frying time. Besides, frying oils with higher content of unsaturated fatty acids were more prone to be oxidized, as well as physicochemical parameters evidencing this phenomenon. Volatile compounds produced by β‐scission homolytic cleavage of peroxide group during thermal oxidation in frying oils were detected by GC‐MS/MS. Results implied major aldehyde volatile compounds were derived from hydroperoxide and oil with higher proportions of unsaturated fatty acids are more likely to produce volatile oxidation products.In order to compare the degree of lipid oxidation in deep‐fried sunflower oil (high degree of unsaturation) and palm oil (high degree of saturation), the formed free radicals based on ESR, along with the assessment of physicochemical parameters including peroxide value, oxidative stability, fatty acid composition, and volatile profile to improve comprehensive assessment of degradation in oil with different fatty acid composition are investigated.

Determination of membrane disruption and genomic DNA binding of cinnamaldehyde to Escherichia coli by use of microbiological and spectroscopic techniques

This work was aimed to investigate the antibacterial action of cinnamaldehyde (CIN) against Escherichia coli ATCC 8735 (E. coli) based on membrane fatty acid composition analysis, alterations of permeability and cell morphology as well as interaction with genomic DNA. Analysis of membrane fatty acids using gas chromatography–mass spectrometry (GC–MS) revealed that the proportion of unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were the major fatty acids in plasmic membrane, and their levels were significantly changed after exposure of E. coli to CIN at low concentrations. For example, the proportion of UFA decreased from 39.97% to 20.98%, while the relative content of SFA increased from 50.14% to 67.80% as E. coli was grown in increasing concentrations of CIN (from 0 to 0.88mM). Scanning electron microscopy (SEM) showed that the morphology of E. coli cells to be wrinkled, distorted and even lysed after exposure to CIN, which therefore decreased the cell viability. The binding of CIN to genomic DNA was probed using fluorescence, UV–Visible absorption spectra, circular dichroism, molecular modeling and atomic force microscopy (AFM). Results indicated that CIN likely bound to the minor groove of genomic DNA, and changed the secondary structure and morphology of this biomacromolecule. Therefore, CIN can be deem as a kind of natural antimicrobial agents, which influence both cell membrane and genomic DNA.

Diapause Induced by Temperature and Photoperiod Affects Fatty Acid Compositions and Cold Tolerance of Phthorimaea Operculella (Lepidoptera: Gelechiidae).

To find out the potential condition for diapause induction in the potato tuber moth Phthorimaea operculella (Zeller), combination of constant temperatures (15, 20, and 30°C) and photoperiods (8, 9, 10, 11, 12, 14, and 16 h) were employed from egg to adult emergence. In addition, changes in the total phospholipid fatty acid content and cold tolerance of non-diapausing and diapausing pupae were examined. The critical daylength for diapause induction were 12.43 h at 20°C and lower temperatures that can induce in 50% of population. Moreover, the composition of total phospholipid fatty acids in the pupae revealed seven major fatty acids in both non-diapausing and diapausing pupae: oleic (26-32%), palmitic (21-29%), linoleic (18-21%), palmitoleic (4-10%), stearic (9%), linolenic (7-8%), and pentadecanoic acids (3-5%) with an increase in proportion of unsaturated fatty acids in diapause state. In contrast to increase of oleic acid (C18:1) from 26 to 32% in non-diapausing to diapausing pupae, a decrement trend from 29 to 21% in palmitic acid (C16:0) was observed at the same state. Additionally, supercooling point was observed to be significantly lower in diapausing (-22.6°C) than in non-diapausing pupae (-18.5°C) and the fresh weight of diapausing pupae was found to be significantly higher than non-diapausing ones. The significance of these findings would allow us a better understanding of interrelationship between diapause and cold tolerance.

New insights in integrated response mechanism of Lactobacillus plantarum under excessive manganese stress

As a natural inhabitant of gastrointestinal tract, Lactobacillus plantarum is well known for its health-promoting effects, especially in heavy metal-removal function. The response mechanism integrated physiology and proteomics of Lactobacillus plantarum under excessive manganese stress was systematically performed. More extracellular polymeric substance was secreted, whereas cells preferred to aggregate for resisting manganese stress. The stability of the membrane was maintained by up-regulating the proportion of unsaturated fatty acids, especially cyclopropane fatty acids. The contents of intracellular Asp and Arg, closely related with energy metabolism, decreased under excessive manganese stress. Comparative 2-DE proteomic analysis identified 52 proteins that significantly differed under different levels of manganese stress. The differentially expressed proteins, involved in the carbohydrate, amino acid, stress response and nucleotide metabolisms, were categorized as the crucial components during resisting manganese stress. Moreover, MntH 4 and MntH 5 were identified as the functional elements in regulation of manganese transportation model. The differential expression of six key transporter proteins under different manganese stresses indicated that the MntH 1, 2 and 3 was negatively regulated by MntR, while the regulation of MntH 4 and 5 presented the contrary model. Taken altogether, the study provides new insights into the response mechanism of probiotics to similar environmental stress.

Metabolic response of Tetragenococcus halophilus under salt stress

In this study, the effect of salt stress on metabolic response of Tetragenecoccus halophilus was investigated, and the metabolic alternations were analyzed using liquid chromatography-mass spectrometry according to the metabolomics approach. A total of 81 intracellular metabolites were identified, and significant differences were observed in the levels of metabolites mainly participating in central carbon metabolism, fatty acid metabolism, and amino acid metabolism. Analysis of the membrane fatty acid distribution showed that higher proportions of unsaturated fatty acid were observed in salt-treated cells. Additionally, salt-stressed cells exhibited higher amounts of compatible solutes including proline, glycine, citrulline, and N-acetyltyrptophan, and lower amounts of branched-chain amino acids. Interestingly, higher amounts of indole, salicylic acid, and coronatine, which are regarded as signaling molecule and suggested to combat osmotic stress, were detected in salt-shocked cells compared with the untreated cells. Taken together, these results suggested that increased unsaturated membrane fatty acids, accumulation of compatible solutes, and up-regulation of signaling molecule may be potential mechanisms employed by T. halophilus during salt stress.

Feeding a concentrate rich in rapeseed oil improves fatty acid composition and flavor in Norwegian goat milk

Impaired quality due to a high content of free fatty acids (FFA) and off-flavors has caused challenges in the development of Norwegian goat milk products. The present study aimed to examine the effect of lipid-supplemented concentrates on milk fat content, fatty acid composition, FFA, lipoprotein lipase activity, sensory properties, and size of milk fat globules of goat milk. Thirty goats assigned to 3 experimental groups were fed different concentrates from 60 d in milk (DIM) until late lactation (230 DIM). The diets were (1) control concentrate (no added fat); (2) control concentrate with 8% (added on air-dry basis) hydrogenated palm oil enriched with palmitic acid (POFA); and (3) control concentrate with 8% (added on air-dry basis) rapeseed oil (RSO). The POFA group produced milk with the highest fat content, and fat content was positively correlated with the mean size of milk fat globules. Goats in the RSO group had a higher content of long-chain and unsaturated fatty acids, whereas milk from goats in the POFA group had a higher content of palmitic and palmitoleic acids (C16:0 and C16:1 cis). The control group produced milk with a higher content of short-, medium-, odd-, and branched-chain fatty acids compared with the 2 other groups. The content of FFA in milk was low in early and late lactation and peaked in mid lactation (90 DIM). A high content of FFA was correlated with poor sensory properties (tart/rancid flavor). The RSO group produced milk with lower content of FFA and off-flavors in mid lactation and a higher proportion of unsaturated fatty acids. Therefore, replacement of palm oil with rapeseed oil as a lipid source in dairy goat feed would be favorable.

Comparison of the effect of Pleurotus citrinopileatus extract and vitamin E on the stabilization properties of camellia oil

We selected Camellia tenuifolia (Hayata) seed oil to compare the effects of mushroom extract and vitamin E on its stabilization properties. Camellia tenuifolia was selected for its higher oil content, but its proportions of unsaturated fatty acids and natural antioxidants as well as its oxidation stability are lower than those of Camellia oleifera oil. Our aim was to improve the oxidation stability, thermal stability, and photodegradation of C. tenuifolia seed oil and then compare the advantages of mixing traditional antioxidant (vitamin E) and mushroom natural antioxidant components (mushroom extract) in the oil. The focus was on the analysis of the effects of Pleurotus citrinopileatus (Singer) extract and vitamin E on the stabilization properties of C. tenuifolia seed oil, which involved some degradation research, such as evaluating the thermal, oxidation, and antioxidant effects as well as the irradiative (pulsed light) stability of the original oil and oil mixed with additives for comparing the differences by differential scanning calorimetry tests and isothermal microcalorimeter (TAM Air) analyses. We determined the effects of stabilization additives vitamin E and various PC extract doses by using pulsed light irradiation (0, 30, and 60 pulses) and found that the 3 mass% PC extract had the best antiphotodegradation characteristics, and the 0.1 mass% vitamin E indicated the outstanding oxidation stability for among all of the additives in this study. Overall, we obtained the following suitable conditions to stabilize camellia oil: addition of vitamin E, addition of 3 mass% PC extract, and a nitrogen atmosphere.

Characteristics and proteomic analysis of pyrene degradation by Brevibacillus brevis in liquid medium

Polycyclic aromatic hydrocarbons (PAHs) are widely spread in various ecosystems and are of great concern due to their potential toxicity, mutagenicity and carcinogenicity. Bioremediation has been proposed as an effective approach to remove PAHs. In this study, the physiological responses and proteome of Brevibacillus brevis under exposure to pyrene, a four-ring compound from PAHs family, were investigated. The changes of cell viability of B. brevis were observed during the degradation of pyrene by means of flow cytometry. The results indicated that pyrene stimulated superoxide dismutase (SOD) activity from 93.9 to 100.6 U mg−1 prot, whereas inhibited catalase (CAT) activity from 29.1 to 20.3 U mg−1 prot. The main compositions of B. brevis changed during pyrene degradation, with the proportion of unsaturated fatty acids increased by 13.4%. In addition, we performed a proteomic approach (two-dimensional gel electrophoresis and MALDI-TOF/TOF-MS) in order to explore how B. brevis survived upon treatment with pyrene. It was showed that the expression of 13 proteins increased whereas 10 other decreased after pyrene-treatment. The differentially expressed proteins were identified and the results indicated that they were involved in multiple biological processes including energy metabolism, biosynthesis, transmembrane transport and oxidative stress. Overall, these findings offered a new insights into the cellular response strategy developed by B. brevis to overcome the pyrene stress.

Enhancing the DHA content in milk from dairy cows by feeding ALL-G-RICH™

SummaryThe objective of this study was to evaluate the effect of the dietary inclusion of 6 g/kg dry matter intake of an unextractedAurantiochytrium limacinumalgae (AURA) in mid-lactation Italian Friesian cows under commercial conditions on milk yield, milk composition and docosahexaenoic acid (DHA) content. Cows were allocated to two groups (n = 18; 108.2 ± 66.1 and 104.4 ± 54.6 days in milk, control and treated groups, respectively). Feeding AURA for 84 d had no effect on dry matter intake, body condition score or weight gain, but did improve milk yield by 1.9 kg/cow/d (+5.4%; P &lt; 0.1) over the course of the experiment. Milk fat concentration declined by 12% (P &lt; 0.0001) without any significant change in 4% fat corrected milk, protein or lactose. Supplementing AURA for 12 weeks substantially altered the fatty acid profile of milk compared with milk from CON-fed cows such that the proportion of unsaturated fatty acids increased, omega-3 fatty acid content increased by 73.1% (P &lt; 0.0001) and was accompanied by a favourable increase in the omega-3:6 fatty acid ratio by 75.0% (P &lt; 0.0001). The AURA supplement, during day 7–84, increased the DHA concentration to 0.37 g /100 g milk total fatty acids (P &lt; 0.0001) with a mean transfer efficiency of 18.1% from feed to milk. Together these results indicated that supplementing a dairy cow diet with DHA-rich microalgae is a feasible and efficient means for creating DHA-enriched milk for human consumption.