For Fatty Acid Research Articles

BnaPPT1 is essential for chloroplast development and seed oil accumulation in Brassica napus

IntroductionPhosphoenolpyruvate/phosphate translocator (PPT) transports phosphoenolpyruvate from the cytosol into the plastid for fatty acid (FA) and other metabolites biosynthesis. ObjectivesThis study investigated PPTs’ functions in plant growth and seed oil biosynthesis in oilseed crop Brassica napus. MethodsWe created over-expression and mutant material of BnaPPT1. The plant development, oil content, lipids, metabolites and ultrastructure of seeds were compared to evaluate the gene function. ResultsThe plastid membrane localized BnaPPT1 was found to be required for normal growth of B. napus. The plants grew slower with yellowish leaves in BnaA08.PPT1 and BnaC08.PPT1 double mutant plants. The results of chloroplast ultrastructural observation and lipid analysis show that BnaPPT1 plays an essential role in membrane lipid synthesis and chloroplast development in leaves, thereby affecting photosynthesis. Moreover, the analysis of primary metabolites and lipids in developing seeds showed that BnaPPT1 could impact seed glycolytic metabolism and lipid level. Knockout of BnaA08.PPT1 and BnaC08.PPT1 resulted in decreasing of the seed oil content by 2.2 to 9.1%, while overexpression of BnaC08.PPT1 significantly promoted the seed oil content by 2.1 to 3.3%. ConclusionOur results suggest that BnaPPT1 is necessary for plant chloroplast development, and it plays an important role in maintaining plant growth and promoting seed oil accumulation in B. napus.

Issue Highlights

Issue Highlights

Odd- and branched-chain fatty acids in milk fat from Holstein dairy cows are influenced by physiological factors

Dairy products are the major source of odd- and branched-chain fatty acids (OBCFAs), a group of nutrients with emerging health benefits. The animal diet is known to influence milk fat OBCFAs of dairy cows; however, little is known about the effects of physiological factors. The objective of this study was to investigate the effects of parity and lactation stage on OBCFAs in milk fat of dairy cows. Holstein dairy cows (n = 157) were selected according to parity (first, second, third, or greater) and days in milk (DIM) (≤21 DIM, 21 < DIM ≤ 100, 100 < DIM ≤ 200, >200 DIM). All cows were fed the same total mixed ration for three weeks. Milk samples were collected during the last three days of each lactation stage for fatty acid (FA) analyses via gas chromatography. Results showed that first- and second-parity cows displayed significantly higher proportions and yields of iso-14:0, iso-15:0, iso-16:0, total iso-FA, and total branched-chain FA (P < 0.05) compared with other parities. The proportions of C17:0 and C17:1 cis-9 were also greater in first-parity cows (P < 0.05), while the yields of C17:0 and C17:1 cis-9 were similar among different parities (P > 0.05). The proportions of total OBCFAs were greater in first- and second-parity cows (P < 0.05), whereas the highest yield was observed in second-parity cows. Lactation dairy cows in ≤ 21 DIM group displayed lower proportions of iso-13:0, anteiso-13:0, C13:0, iso-14:0, C15:0, iso-16:0, total iso-FA, and total OBCFAs compared with that of the other groups (P < 0.05), and also lower yields of iso-14:0 and iso-16:0 (P < 0.05). In contrast, C17:0 and C17:1 cis-9 proportions and yields were higher in dairy cows with ≤ 21 DIM (P < 0.05). Iso-17:0 and anteiso-17:0 were not affected by lactation stage (P > 0.05). Taken together, our data showed that both parity and lactation stage have considerable effects on milk fat OBCFAs of dairy cows. In summary, first- and second-parity cows had higher milk OBCFAs compared with later parity cows, and OBCFAs with medium chain lengths were lower in dairy cows with ≤ 21 DIM, while C17:0 and C17:1 cis-9 were higher. These findings show that milk OBCFA contents are differentially modulated by physiological state. They will be useful in future studies that seek to alter OBCFA composition of Holstein dairy cow milk fats.

Validation of quantitative fatty acid signature analysis for estimating the diet composition of free-ranging killer whales

Accurate diet estimates are necessary to assess trophic interactions and food web dynamics in ecosystems, particularly for apex predators like cetaceans, which can regulate entire food webs. Quantitative fatty acid analysis (QFASA) has been used to estimate the diets of marine predators in the last decade but has yet to be implemented on free-ranging cetaceans, from which typically only biopsy samples containing outer blubber are available, due to a lack of empirically determined calibration coefficients (CCs) that account for fatty acid (FA) metabolism. Here, we develop and validate QFASA for killer whales using full blubber from managed-care and free-ranging individuals. First, we compute full, inner, and outer blubber CCs from the FA signatures across the blubber layers of managed-care killer whales and their long-term diet items. We then run cross-validating simulations on the managed-care individuals to evaluate the accuracy of diet estimates by comparing full-depth and depth-specific estimates to true diets. Finally, we apply these approaches to subsistence-harvested killer whales from Greenland to test the utility of the method for free-ranging killer whales, particularly for the outer blubber. Accurate diet estimates for the managed-care killer whales were only achieved using killer whale-specific and blubber-layer-specific CCs. Modeled diets for the Greenlandic killer whales largely consisted of seals (75.9 ± 4.7%) and/or fish (20.4 ± 2.4%), mainly mackerel, which was consistent with stomach content data and limited literature on this population. Given the remote habitats and below surface feeding of most cetaceans, this newly developed cetacean-specific QFASA method, which can be applied to outer-layer biopsies, offers promise to provide a significant new understanding of diet dynamics of free-ranging odontocetes and perhaps other cetacean species throughout the world’s oceans.

Maternal erythrocyte fatty acid composition as a predictive marker for pregnancy health.

Pregnancy is accompanied by a surge in demand for fatty acids (FAs) in order to support maternal health, as well as fetal growth and development. Of particular demand is essential for long-chain polyunsaturated FAs. FAs are primarily obtained from dietary sources and are distributed in the body. In comparison with the use of self-reporting approaches, measuring the FA levels within different blood compartments can present a more accurate image of nutritional, and thus tissue, FA composition. Hence, the FA profile of plasma or serum is commonly used for physiological analyses. Nevertheless, plasma and serum FAs are not yet incorporated into cell membranes, and consequently may not be a suitable reflection of the FA status of body tissues. The evaluation of erythrocyte FA levels offers a superior possibility for the following reasons: the biological fluctuation of erythrocyte FA composition is low, phospholipids account for almost all the lipid content of erythrocytes, and the FA profiles of erythrocytes represent those of tissues. Here, we elaborate on whether the status of maternal erythrocyte FAs can serve as a prognostic biomarker for reproductive health and fetomaternal complications, including embryonic and fetoplacental development, gestational length, and preeclampsia. In addition, factors with the potential of altering the maternal erythrocyte FAs such as maternal diet, lifestyle habits, genetics, and body composition are discussed.

Reduced n-3 and n-6 PUFA (DHA and AA) Concentrations in Breast Milk and Erythrocytes Phospholipids during Pregnancy and Lactation in Women with Obesity.

Obesity during pregnancy is a worrying public health problem worldwide. Maternal diet is critical for fatty acid (FA) placental transport and FA content in breast milk (BM). We evaluated FA composition in erythrocytes phospholipids (EP) and BM in pregnant women with (OBE, n = 30) and without (non-OBE, n = 31) obesity. Sixty-one healthy women were evaluated at their 20–24th gestational week and followed until 6th month of lactation. Diet was evaluated through a food frequency questionnaire. FA composition of EP and BM was assessed by gas-liquid chromatography. The OBE group showed lower diet quality, but total n-6 and n-3 polyunsaturated FA (PUFA), ALA, EPA, and DHA dietary intake was similar between groups. N-3 PUFA, ALA, DHA, and the n-6/n-3 PUFA ratio in EP were lower at the 6th lactation month in the OBE group. In BM, the arachidonic acid (AA) concentration was lower at the end of the lactation, and DHA content showed an earlier and constant decline in the OBE group compared to the non-OBE group. In conclusion, n-3 PUFA and AA and DHA levels were reduced in EP and BM in pregnant women with obesity. Strategies to increase n-3 PUFA are urgently needed during pregnancy and lactation, particularly in women with obesity.

Microbial β-oxidation of synthetic long-chain fatty acids to improve lipid biomethanation

β-oxidation is a well-known pathway for fatty acid (FA) degradation. However, the wide range of feedstocks, their intermediates, and complex microbial networks involved in anaerobic digestion (AD) make β-oxidation unclear during lipid digestion having a variety of long-chain fatty acids (LCFAs). Here, we demonstrated the detailed metabolic pathway of major bacteria and enzymes responsible for the β-oxidation of individual saturated FAs (C16:0 and C18:0) and unsaturated FAs (C18:1 and C18:2). C16:0 showed no negative impact on AD. The relative enzyme abundance and production of shorter-chain FAs (<C16) were steady with continuous biomethane production (739 mL g−1 VS). C18:0 and C18:1 demonstrated a significant AD inhibition. By contrast, C18:2 demonstrated effective degradation and biomethanation. These results indicate that β-oxidation is directly initiated from saturated C16:0 FAs. The presence of C18:0, C18:1, and C18:2 significantly reduced microbial diversity, which recovered in the presence of C16:0. The bacterial genera Clostridium sensu stricto 1, Syntrophomonas, and Sedimentibacter were found in high abundance indicating they might be responsible for most LCFA degradation that resulted in biomethane precursors. Acetoclastic and hydrogenotrophic methanogens were inhibited in the presence of C18:0, C18:1, and C18:2 FAs. Conversion of these FAs to C16 and shorter-chain FAs revived the methanogens. The level of the initiator enzyme of β-oxidation “LCFA-CoA ligase” was increased after the conversion of C18:0, C18:1, and C18:2 to C16:0. The production of other FAs (i.e., <C16) leads to a slight improvement in biomethanation.

Genetic Analysis of the Fatty Acid Profile in Gilthead Seabream (Sparus aurata L.).

Simple SummaryHumans require essential fatty acids in their diet and marine fish are a source of them, especially omega3 fatty acids that present high benefits on diverse vascular diseases and the immune system. Breeding programs in gilthead seabream usually include growth as the first criterion in the selection process of the fish. However, that could lead to fish with a higher fillet fat content and a fatty acid profile with a lower polyunsaturated fatty acids percentage. Fillet fat content and its fatty acids profile have been revealed as heritable traits. Therefore, further studies to go deeper in the selection process are advisable.The gilthead seabream is one of the most valuable species in the Mediterranean basin both for fisheries and aquaculture. Marine fish, such as gilthead seabream, are a source of n3 polyunsaturated fatty acids, highly appreciated for human food owing to their benefits on the cardiovascular and immune systems. The aim of the present study was to estimate heritability for fatty acid (FA) profile in fillet gilthead seabream to be considered as a strategy of a selective breeding program. Total of 399 fish, from a broodstock Mediterranean Sea, were analysed for growth, flesh composition and FA profile. Heritabilities for growth traits, and flesh composition (fat, protein, and moisture content) were medium. Heritability was moderate for 14:0, 16:0 and 18:1n9 and for sum of monounsaturated FA and n6/n3 ratio, and it was low for 20:1n11 and 22:6n3 and the ratio unsaturated/saturated FA. Breeding programs in gilthead seabream usually include growth as the first criterion in the selection process of the fish. However, other quality traits, such as fillet fat content and its fatty acids profile should be considered, since they are very important traits for the consumer, from a nutritional point of view and the benefits for the health.

Role of peroxisome proliferator-activated receptor gamma (PPARγ) in the regulation of fatty acid metabolism related gene expressions in testis of men with impaired spermatogenesis

Although male infertility is a multifactorial syndrome in which genetic factors are responsible for up to 15 % of cases, there are few studies of genes involved in lipid metabolism and male infertility. Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor in testis tissue. PPARγ binds to DNA and regulates the genes for fatty acid (FA) metabolism. Thus, it has a key role in male reproduction. The current study assessed the expressions of fatty acid desaturase 2 (FADS2), elongation of very‐long‐chain fatty acids‐like 2 (ELOVL2), stearoyl-CoA desaturase-1 (SCD), and lipoprotein lipase (LPL) and incorporation of PPARγ in the promoter regions of these genes in testicular tissue biopsies from 30 infertile males who underwent testicular sperm extraction. The samples were classified into three groups: obstructive azoospermia (OA), which was the positive control (n = 10); round spermatid maturation arrest (SMA, n = 10); and Sertoli cell-only syndrome (SCOS, n = 10). There were significantly lower relative mRNA expression levels of the FADS2, ELOVL2, SCD, and LPL genes in the SCOS (P < 0.01) and SMA (P < 0.01) groups compared to the OA control group. We observed a significant decrease in chromatin incorporation of PPARγ on the promoter regions of the candidate FA metabolism genes (P < 0.05). For the first time, the present study results show that PPARγ is a strong mediator for regulation of FA metabolism in human testis tissue and we confirmed its critical role in normal spermatogenesis.

Mobilizing Vacuolar Sugar Increases Vegetative Triacylglycerol Accumulation.

Photosynthetically derived sugars provide carbon skeletons for metabolism and carbon signals that favor anabolism. The amount of sugar available for fatty acid (FA) and triacylglycerol (TAG) synthesis depends on sugar compartmentation, transport, and demands from competing pathways. We are exploring the influence of sugar partitioning between the vacuole and cytoplasm on FA synthesis in Arabidopsis by building on our previous finding that reduced leaf sugar export in the sucrose-proton symporter2 (suc2) mutant, in combination with impaired starch synthesis in the ADP-glucose pyrophosphorylase (adg1) mutant, accumulates higher sugar levels and increased total FA and TAG compared to the wild type parent. Here we sought to relocalize sugar from the vacuole to the cytoplasm to drive additional FA/TAG synthesis and growth. Arabidopsis suc2 adg1 was therefore crossed with tonoplast monosaccharide transporter mutants tmt1 and tmt2 and overexpression of the sucrose/proton cotransporter SUC4 in which tmt1 tmt2 impairs sugar transport to the vacuole from the cytoplasm and SUC4 overexpression enhances sugar transport in the reverse direction from the vacuole to the cytoplasm. A resulting homozygous suc2 adg1 tmt1 tmt2 SUC4 line was used to test the hypothesis that increased intracellular carbon supply in the form of sugars would increase both FA and TAG accumulation. The data shows that relative to suc2 adg1, suc2 adg1 tmt1 tmt2 SUC4 significantly increases leaf total FA content by 1.29-fold to 10.9% of dry weight and TAG by 2.4-fold to 2.88%, supporting the hypothesis that mobilizing vacuolar sugar is a valid strategy for increasing vegetative oil accumulation.

Targeting lipid metabolism is an emerging strategy to enhance the efficacy of anti-HER2 therapies in HER2-positive breast cancer.

De novo or acquired resistance of cancer cells to currently available Human Epidermal Growth Factor Receptor 2 (HER2) inhibitors represents a clinical challenge. Several resistance mechanisms have been identified in recent years, with lipid metabolism reprogramming, a well-established hallmark of cancer, representing the last frontier of preclinical and clinical research in this field. Fatty Acid Synthase (FASN), the key enzyme required for fatty acids (FAs) biosynthesis, is frequently overexpressed/activated in HER2-positive (HER2+) breast cancer (BC), and it crucially sustains HER2+ BC cell growth, proliferation and survival. After the synthesis of new, selective and well tolerated FASN inhibitors, clinical trials have been initiated to test if these compounds are able to re-sensitize cancer cells with acquired resistance to HER2 inhibition. More recently, the upregulation of FA uptake by cancer cells has emerged as a potentially new and targetable mechanism of resistance to anti-HER2 therapies in HER2+ BC, thus opening a new era in the field of targeting metabolic reprogramming in clinical setting. Here, we review the available preclinical and clinical evidence supporting the inhibition of FA biosynthesis and uptake in combination with anti-HER2 therapies in patients with HER2+ BC, and we discuss ongoing clinical trials that are investigating these combination approaches.

Season and geography induced variation in sea cucumber (Stichopus japonicus) nutritional composition and gut microbiota

Sea cucumber (Stichopus japonicus) is considered as one of the most nutritious and luxurious seafood in Asia. This study investigated the variation in biochemical composition and gut microbes of sea cucumber related to seasons (spring and autumn) and geographical origins (Qingdao, Yantai, Weihai and Dalian) in China. In general, sea cucumber had relatively low fat and high protein. The composition variation between seasons is much more obvious than that of origins, especially for fatty acids (FA) and amino acids. Sea cucumber collected in spring contained more poly-unsaturated fatty acids (PUFA) and Asp, Glu, Leu, Phe than that of autumn. Furthermore, FA varied among origins and seasons, with the highest content of DHA found in the location of Weihai collected in spring. In addition, gut microbes changed among origins and seasons. Proteobacteria and Bacteroidetes decreased significantly from autumn to spring and Firmicutes showed the opposite trend. The variation in protein, lipid, polysaccharides, elements and gut microbes of sea cucumber between seasons and origins might be related to environmental conditions. This study may help to better understand the variation of biochemical composition and gut microbiota of sea cucumber among different origins and seasons.

Mycosis fungoides and Sézary syndrome tumor cells express epidermal fatty acid-binding protein, whose expression decreases with loss of epidermotropism.

Fatty acid binding protein (FABP) is a family of transport proteins for fatty acid (FA). Epidermal FABP (E-FABP) is highly expressed by resident memory T cells (TRM ) in the skin. It supports the uptake of exogenous FA for long-term survival of skin TRM . Mycosis fungoides (MF) is regarded as malignancy of skin TRM . In this study, we investigated E-FABP expression in psoriasis vulgaris (PV), atopic dermatitis (AD), MF, and Sézary syndrome (SS). E-FABP mRNA levels in PV were much higher than those in healthy controls. E-FABP mRNA levels in AD and MF/SS lesional skin were also significantly higher than those of normal skin. By immunohistochemical staining, E-FABP was positive in MF/SS lesional skin. Interestingly, E-FABP was stained positive in epidermotropic lymphoid cells in patch, plaque, and erythrodermic lesions of MF/SS, suggesting that a part of tumor cells expressed E-FABP. In tumorous lesions, however, most dermal tumor cells were negative for E-FABP. Immunohistochemical staining using patch/plaque lesions and tumorous lesions from the same patients also revealed that E-FABP expression decreased in tumorous lesions. Our study has suggested that MF/SS tumor cells express E-FABP, whose expression decreases with loss of epidermotropism.

The Pancreatic β-Cell: The Perfect Redox System.

Pancreatic β-cell insulin secretion, which responds to various secretagogues and hormonal regulations, is reviewed here, emphasizing the fundamental redox signaling by NADPH oxidase 4- (NOX4-) mediated H2O2 production for glucose-stimulated insulin secretion (GSIS). There is a logical summation that integrates both metabolic plus redox homeostasis because the ATP-sensitive K+ channel (KATP) can only be closed when both ATP and H2O2 are elevated. Otherwise ATP would block KATP, while H2O2 would activate any of the redox-sensitive nonspecific calcium channels (NSCCs), such as TRPM2. Notably, a 100%-closed KATP ensemble is insufficient to reach the −50 mV threshold plasma membrane depolarization required for the activation of voltage-dependent Ca2+ channels. Open synergic NSCCs or Cl− channels have to act simultaneously to reach this threshold. The resulting intermittent cytosolic Ca2+-increases lead to the pulsatile exocytosis of insulin granule vesicles (IGVs). The incretin (e.g., GLP-1) amplification of GSIS stems from receptor signaling leading to activating the phosphorylation of TRPM channels and effects on other channels to intensify integral Ca2+-influx (fortified by endoplasmic reticulum Ca2+). ATP plus H2O2 are also required for branched-chain ketoacids (BCKAs); and partly for fatty acids (FAs) to secrete insulin, while BCKA or FA β-oxidation provide redox signaling from mitochondria, which proceeds by H2O2 diffusion or hypothetical SH relay via peroxiredoxin “redox kiss” to target proteins.

Lipid Fractions, Fatty Acid Profiles, and Bioactive Compounds of Lithospermum officinale L. Seeds

AbstractSeeds of Lithospermum officinale L. from different climatic zones were analyzed for new sources of γ‐linolenic acid (GLA, 18:3n‐6) and stearidonic acid (SDA, 18:4n‐3). Cultured Borago officinalis was also analyzed for comparative purposes. Analyses were conducted for fatty acid (FA) profiles of the glyceride oils from the seeds and in the neutral and polar lipids by gas chromatography (GC); lipid classes by open column chromatography and preparative thin layer chromatography (TLC); and tocopherols, sterols, and phenolic compounds by high‐performance liquid chromatography with diode array detection (HPLC‐DAD), and the later compounds were confirmed by liquid‐chromatography‐mass spectrometry (LC–MS). L. officinale from St. Petersburg Botanical Garden showed the highest percentage of GLA (17.9% of total FA), while wild‐growing L. officinale from the Rostov region contained the highest percentage of SDA (17.2% of total FA). Total FA content ranged from 11.3 to 20.8% of seed weight. Neutral and polar lipids accounted for ~98 and 2.27%, respectively, of total lipids. Five neutral lipid classes were identified (% of NL): triterpene esters (1.3), triacylglycerols (93.1), free FA (1.8), diacylglycerols (1.4), and monoacylglycerols (2.4). The highest tocopherol content was found in samples from Chechen Republic (35.7 mg/100 g), in which the δ isomer was the main component. Samples from the Rostov region had the highest amounts of sterols (83.8 mg/100 g), and Δ5‐avenasterol was the predominant compound in all samples. L. officinale seeds contain high amounts of phenolic compounds (389.9 mg/100 g as upper limit), in which rosmarinic acid is highlighted. Overall, all data suggest the possibility of using L. officinale seed oil in pharmaceutical and cosmetic formulae and as functional food.

Expression and prognostic significance of fatty acid synthase in clear cell renal cell carcinoma

Fatty acid synthase (FASN), a key enzyme essential for fatty acid (FA) synthesis, was reportedly implicated in the initiation and progression of various cancers. However, the clinical significance of FASN in renal cell carcinoma (RCC) has not been fully elucidated yet. Here we compare the expression profile and evaluate the prognostic significance of FASN in clear cell RCC (ccRCC) patients. FASN expression was examined in 3 pairs ccRCC and their adjacent nontumor tissues by western blotting (WB) analysis, and its expression was assessed in 145 ccRCC and 13 nontumor tissues by immunohistochemistry (IHC) analysis with tissue microarrays (TMAs). The prognosis of FASN was further investigated in large-scale database using LinkedOmics (n = 537) and The Cancer Protein Atlas (TCPA, n = 445), respectively. WB detected higher FASN expression in ccRCC than normal tissues, then IHC analysis revealed that FASN expression was positively associated with histological grade, pathological stage, tumor size and metastasis status, and negatively associated with cancer-specific survival (CSS). Univariate survival analysis demonstrated that high grade, advanced stage, large tumor, metastasis, and high FASN expression were significantly associated with a shorter CSS, and multivariate analysis revealed tumor grade, stage, metastasis and FASN were identified as independent predictors for CSS in patients with ccRCC. Further LinkedOmics and TCPA analyses confirmed that high FASN expression was correlated with a poorer overall survival (OS) of ccRCC. Collectively, these findings demonstrated FASN could be a poor prognostic factor in ccRCC patients, which indicated that FA synthesis might be implicated in the tumorigenesis and progression of ccRCC.

Effects of dietary polyunsaturated fatty acid sources on expression of lipid-related genes in bovine milk somatic cells

The objective of this study was to compare the effect of contrasting sources of dietary n-6 and n-3 PUFA on expression of genes related to lipid metabolism in dairy cows. During 63 days, fifteen lactating cows were assigned to a control or basal diet containing no added lipid (n = 5 cows); and treatment diets supplemented with SO (n = 5 cows; unrefined soybean oil; 2.9% of DM) or FO (n = 5 cows; fish oil manufactured from salmon oil; 2.9% of DM). Plasma for fatty acid (FA) analysis and milk somatic cells (MSC) were obtained from all cows at the beginning of the study (day 0) and on days 21, 42 and 63. Plasma was used to determine FA transport dynamics. Compared with control and FO, plasma from SO had increased contents of C18:1 cis-9, C18:1 trans-11, C18:2 cis-9, trans-11 and total monounsaturated FA. On the other hand, compared with control and SO, FO increased plasma contents of C20:3 n-3, C20:3 n-6, C20:4 n-6, C20:5 n-3, C22:6 n-3 and total polyunsaturated FA. Moreover, plasma C18:3 n-3 and C20:5 n-3 increased over time for all diets. Compared with control, SO downregulated ACACA, INSIG1, and DGAT1, whereas FO downregulated ACACA, PPARGC1, LPIN1 and FABP3 on day 63, in MSC. At different time-points, SO and FO downregulated genes related to synthesis and intracellular transport of FA, synthesis of triglycerides, and transcription factors.

Characterisation and differentiation of geographical origin of Graviera cheeses produced in Greece based on physico-chemical, chromatographic and spectroscopic analyses, in combination with chemometrics

A total of 90 Graviera cheese samples, produced by selected local dairies in six different regions of Greece, were analysed for pH, titratable acidity, NaCl, proteins, fat on dry weight basis, ash, fatty acid composition by gas chromatography, volatile compounds by gas chromatography/mass spectrometry, and minerals by inductively coupled plasma - optical emission spectrometry, in an effort to differentiate Graviera cheeses according to geographical origin. Statistical treatment of the data included multivariate analysis of variance and linear discriminant analysis. The results showed that individual analytical parameters gave a correct classification of 46.7% for volatile compounds (VCs), 86.7% for physico-chemical parameters (PCPs), 91.1% for fatty acids (FAs) and 91.2% for minerals. Respective values for combinations of analytical parameters were 93.3% for PCPs plus FAs, 93.4% for PCPs plus FAs plus minerals, and 97.8% for FAs plus minerals.

Effect of Deep Frying on Fatty Acids Profile of Fried Chicken and Tilapia

The present study was designed to keep track of a real-life path to what happens in frying oil when meat is fried in it. It was designed to examine the fatty acid profile in the fried meat in random samples collected from the Ismailia marketplace and other homemade. Generally, there were significant difference (P<0.05) between the fried chicken samples of the market and homemade for fatty acids (FA) content. The increased content of FA was toward the market samples. trans-9 elaidic acid, could not be detected in homemade fried chicken. Repetitive use of oil at high temperature in the presence of wetness and air causes thermal degradation of oil. Deep fat frying (DFF) can lead to the formation of trans fatty acids (TFAs).

Fatty acid profile and physicochemical properties of Greek protected designation of origin cheeses, implications for authentication

Greek protected designation of origin (PDO) cheeses are well-known for their quality and nutritive value. One hundred and twelve samples from 21 Greek PDO cheeses, a non-PDO and a potential PDO were analyzed for fatty acid (FA) profile and several physicochemical parameters including moisture, fat on dry matter (FDM), protein content, pH and salt content. Analyzed hard and semi-hard cheeses were Sfela, Kefalograviera, Kasseri, Ladotyri Mytilinis, Formaella Arachovas Parnassou, Graviera Agrafon, Graviera Kritis, Metsovone, Graviera Naxou, Mastelo, Batzos and San Michali. Soft, spread and whey cheeses included Kopanisti, Xynomyzithra Kritis, White cheese, Kalathaki Limnou, Manouri, Feta, Xygalo Siteias, Galotyri, Katiki Domokou, Pichtogalo Chanion and Anevato. The profile of 37 FAs combined with physiochemical properties was utilized to discriminate cheeses by label (cheese identity), cheese type (hard, semi-hard, soft, spread and whey) and milk type (cow, goat, sheep and combinations). The study found that Sfela had the highest salinity, Manouri the highest FDM and San Michali the highest content of proteins. Regarding FAs, the dominant ones in almost all cheeses were C14:0, C16:0, C18:0 and cis-9 C18:1. For classification concerning cheese identity, the most significant parameters were moisture, fat, C18:2n-6c, pH and salt. The most significant discriminants by cheese type were pH, moisture, FDM, salt and C16:0 while C10:0, C11:0, C14:1, C18:2n-6c, C20:0, C20:3n-6 and saturated FAs were more influential to separate by milk type. Results depict the FA profile of Greek PDO cheeses and show that in combination with physicochemical characteristics can be used as authenticity markers.