The content- and odor-advantaged volatile compounds and the visualized characteristic odor profile of n-3 PUFA-rich fried pork meat obtained from finishing pigs fed a diet enriched with linseed oil and selenomethionine.

We hypothesized that the polyunsaturated fatty acids of the butterfly were probably derived from the diet and that there might be a great loss of body fat during metamorphosis. To substantiate these hypotheses, we analyzed the fatty acid composition and content of the diet, the larva, and the butterfly Morpho peleides. Both the diet and the tissues of the larva and butterfly had a high concentration of polyunsaturated fatty acids. In the diet, linolenic acid accounted for 19% and linoleic acid for 8% of total fatty acids. In the larva, almost 60% of the total fatty acids were polyunsaturated: linolenic acid predominated at 42% of total fatty acids, and linoleic acid was at 17%. In the butterfly, linolenic acid represented 36% and linoleic acid represented 11% of total fatty acids. The larva had a much higher total fatty acid content than the butterfly (20.2 vs. 6.9 mg). Our data indicate that the transformation from larva to butterfly during metamorphosis drastically decreased the total fatty acid content. There was bioenhancement of polyunsaturated fatty acids from the diet to the larva and butterfly. This polyunsaturation of membranes may have functional importance in providing membrane fluidity useful in flight.

Thioesterase activity is typically required for the release of products from polyketide synthase enzymes, but no such enzyme has been characterized in deep-sea bacteria associated with the production of polyunsaturated fatty acids. In this work, we have expressed and purified the Orf6 thioesterase from Photobacterium profundum. Enzyme assays revealed that Orf6 has a higher specific activity toward long-chain fatty acyl-CoA substrates (palmitoyl-CoA and eicosapentaenoyl-CoA) than toward short-chain or aromatic acyl-CoA substrates. We determined a high resolution (1.05 Å) structure of Orf6 that reveals a hotdog hydrolase fold arranged as a dimer of dimers. The putative active site of this structure is occupied by additional electron density not accounted for by the protein sequence, consistent with the presence of an elongated compound. A second crystal structure (1.40 Å) was obtained from a crystal that was grown in the presence of Mg(2+), which reveals the presence of a binding site for divalent cations at a crystal contact. The Mg(2+)-bound structure shows localized conformational changes (root mean square deviation of 1.63 Å), and its active site is unoccupied, suggesting a mechanism to open the active site for substrate entry or product release. These findings reveal a new thioesterase enzyme with a preference for long-chain CoA substrates in a deep-sea bacterium whose potential range of applications includes bioremediation and the production of biofuels.

Macadamia is a subtropical tree originating from Australia. The kernels are rich in monounsaturated fatty acids and may reduce serum cholesterol when included in the diet. It can be assumed that this is due to a particularly high oleic acid content of the nut oil. In general, an average ratio of unsaturated to saturated fatty acids in macadamia nuts is 5.5:1. High content of unsaturated fatty acid leads to oxidative reactions and results in rancidity which decreases quality of macadamia nuts. Moreover, processing methods and storage can have a major impact on changes in quality of macadamia nuts. Therefore, the proposed research aims at investigating the changes of flavour and lipid composition during macadamia nut processing. The latter includes drying, roasting and storage of macadamia nuts. Two methods of drying were employed in this study. Hot air drying (HA) (30°C for 7 days, 40°C for 7 days, 60°C for 3 days) and heat pump drying (HP) (38 °C,1 day, 8% wb) followed by tunnel dryer (TD) (55°C, 2 days) were used to dry macadamia nuts until their moisture content came down to 1.5% wb. This was followed by roasting at 125 °C for 20 minutes until the kernel moisture content reached 1% wb. The final phase of the experiment was storage at 4°C for 3 months. After each processing stage the quality of macadamia nuts was assessed in terms of fatty acid content, volatile compounds, colour, peroxide value, free fatty acids and moisture content. The result showed a decrease of fatty acid content (p[is less than or equal to]0.05) among unsaturated fatty acids such as C16:1, C18:1 and saturated fatty acids such as C14:0, C18:0, C20:0 and C22:0 after drying with HA drying as well as the decreasing of fatty acid content (p[is less than or equal to]0.05) among unsaturated fatty acids such as C18:1 and saturated fatty acids such as C12:0 and C22:0 after drying with HP+TD drying. The decomposition of fatty acids contributed to an increase in the level of total aldehydes, total alcohols and total hydrocarbons. Moreover, free fatty acids and peroxide value increased significantly (p[is less than or equal to]0.05) after drying. HP + TD drying can reduce decomposition of fatty acids during drying more than HA drying. Final content of oleic acid decreased from 59.3 to 45.5 and 62.3 to 57.3 mg/100 g db after HA and HP + TD drying, respectively. The increasing values of hexanal, total alcohols, aldehydes and hydrocarbons after HA drying were more pronounced than after HP + TD drying. The degradation of fatty acids continued during roasting and storage. In addition to that, a small degradation was found during roasting and storage of macadamia nuts at low moisture content after roasting (1% wb). It can be concluded that HP + TD drying showed benefit of time saving and natural quality preservation of the macadamia nuts vs. than HA drying. Although, the changes of fatty acids, volatile compounds, colour and rancidity after drying and roasting continued during storage of macadamia nuts, they occurred at a slow rate. The final values of peroxide value, free fatty acid and colour were within acceptable limits after three months of storage.

Omega-3 Fatty Acids for Maintenance of Remission of Crohn's Disease

The epidemiological studies of Kromann and Green1 on the low mortality rate of Greenland Inuits from ischemic heart disease led to the suggestion by Bang et al2 that despite the high total fat intake of the Eskimos, this low mortality rate was due to the abundance of n-3 fatty acids from seafood in their diet. This hypothesis initiated research by many investigators into possible antiatherogenic effects of n-3 PUFAs. Much has been learned regarding physiological and biochemical changes induced by this class of essential fatty acids that could have potential antiatherogenic effects; nevertheless, controversy persists in the current literature regarding the clinical evidence for beneficial effects from fish ingestion (the major dietary source of n-3 fatty acids) on the development of coronary heart disease.3 4 Studies seeking a resolution to the potential antiatherogenic effects of n-3 PUFA will undoubtedly continue.5 Meanwhile, on the basis of earlier sporadic suggestions that n-3 PUFA might possess antiarrhythmic effects,6 7 McLennan and coworkers8 9 pursued this possibility. They showed in feeding studies in rats that when saturated fats or olive oil is the major dietary fat, a high incidence of fatal, irreversible VF occurs from experimental coronary artery ligation, which was significantly reduced when the dietary fat was vegetable oil but was essentially abolished by fish oil. They have confirmed their basic finding in marmosets.10 It is not our purpose in this brief review to discuss possible antiatherogenic effects of n-3 PUFA or the role of coronary heart disease in causing malignant ventricular arrhythmias. Clearly, coronary heart disease is the major clinical setting in which malignant ventricular arrhythmias occur today, and myocardial ischemia is the most common trigger eliciting such arrhythmias. Rather, we will focus on our recent studies on the mechanism of the apparent antiarrhythmic actions …

The selectivity and efficiency of urea complex (UC) formation‐based fractionation of free fatty acids (FFA) were examined. A rapid, simple, and inexpensive procedure recently developed for urea fractionation was applied to lipid mixtures containing various polyunsaturated and hydroxy FFA species. Urea treatment proved useful for isolating polyunsaturated FFA (PUFA) from FFA derived from fish, borage, and linseed oils by removal of saturated and monounsaturated FFA, but was not effective for isolating hydroxy FFA from the FFA derived from castor, Lesquerella, and Dimorphotheca oils. In situations where FFA within the crystalline or UC phase were rich in PUFA, the urea/FFA mole ratio of the UC was relatively higher, with lower recovery of FFA in this phase. The distribution of urea between the crystalline phase and the solvent was not significantly affected by the FFA composition of feed nor the overall ratio of FFA to urea. It was strongly dependent on the overall mass fraction of solvent. Phospholipids and mono‐, di‐, and triacylglycerols were poor templates for UC formation relative to FFA. Their inclusion in acylglycerol mixtures containing FFA reduced UC formation.

Acute grazer toxicity of freshwater diatom biofilms was determined using Thamnocephalus platyurus Packard, an anostracan grazer, as the bioassay organism. The diatoms exhibited toxicity when the cells of the biofilm were freeze–thawed before the assay. The toxicity could be extracted from the biofilms with methanol and acetone, and only minimal toxicity was left in the insoluble residue. Bioassay‐guided HPLC separation of the methanolic extract was performed to trace the most toxic components. Analysis by UV spectrometry, gas chromatography, and mass spectrometry showed that 5,8,11,14,17‐eicosapentaenoic acid was responsible for most grazer toxicity. The 24‐h LC50 of this polyunsaturated fatty acid was 34 μM in the Thamnocephalus platyurus bioassay. The concentrations of other free fatty acids were not high enough to contribute significantly to the toxicity. Procedures that affected the integrity of the cells (e.g. solvent extraction, freezing and thawing, osmotic stress by addition of 20% NaCl, or grinding the cells in a mortar) were taken as model reactions for grazing and had the common effect of resulting in a dramatic increase of free polyunsaturated and saturated fatty acids. Under these conditions, about 30% of the total fatty acids of the diatoms was transformed from the bound into the free form. The time necessary for liberation was very short. With the exception of 5,8,11,14,17‐eicosapentaenoic acid, which continued to be liberated, the hydrolysis of the other fatty acids was terminated less than 1 min after initiating the reaction. The classical extraction procedures using methanol and other solvents led to the appearance of a high percentage of free fatty acids in live cells. Treatment of biofilms with these solvents did not stop the hydrolysis of lipids initiated by the disintegration of the cells. However, boiling acetone completely suppressed the hydrolytic reactions, and free polyunsaturated fatty acids were not detected in live biofilm organisms, although nontoxic saturated fatty acids were present in moderate concentrations. These results were interpreted as an indication that the frequently reported existence of free polyunsaturated fatty acids in live biomass is an analytical artifact.

Despite the dietary utilization of the coconut crab Birgus latro throughout history, little is known about its nutritional composition and quality. This study assessed the differences between male and female coconut crabs caught in Okinawa, southwest Japan, in meat yield and compositions of free amino acids (FAA), nucleotide-related compounds (NRC), and fatty acids in muscle and hepatopancreas. The ratios of edible muscle and hepatopancreas to whole body weight were similar in males and females. Although concentrations of histidine and tryptophan in muscle and AMP in hepatopancreas differed in males and females, these differences were small, as were taste activities and equivalent umami concentrations, suggesting that the tastes of these tissues in males and females would be nearly identical. Fatty acid composition in muscle differed lightly between the sexes, with amounts of the 20:5n-3 and 22:6n-3 being significantly greater in males. However, the ratio of n-3 to n-6 polyunsaturated fatty acids and atherogenic and thrombogenic indices suggested that all lipids from both males and females are healthy for humans. There were no noticeable differences between the sexes in meat yield; FAA, NRC and fatty acid compositions; or nutritional qualities.

The effect of thermal times of circulating non-fried roast technique on the formation of (non)volatile compounds in roasted mutton by multi-chromatography techniques and heat transfer analysis

The purpose of this investigation was to determine whether diets supplemented with oils from three different marine sources, all of which contain high proportions of long-chain n-3 polyunsaturated fatty acids (PUFA), result in qualitatively distinct lipid and fatty acid profiles in guinea pig heart. Albino guinea pigs (14 days old) were fed standard, nonpurified guinea pig diets (NP) or NP supplemented with menhaden fish oil (MO), harp seal oil (SLO) or porbeagle shark liver oil (PLO) (10%, w/w) for 4-5 weeks. An n-6 PUFA control group was fed NP supplemented with corn oil (CO). All animals appeared healthy, with weight gains marginally lower in animals fed the marine oils. Comparison of relative organ weights indicated that only the livers responded to the diets, and that they were heavier only in the marine-oil fed guinea pigs. Heart total cholesterol levels were unaffected by supplementing NP with any of the oils, whereas all increased the triacylglycerol (TAG) content. The fatty-acid profiles of total phospholipid (TPL), TAG and free fatty acid (FFA) fractions of heart lipids showed that feeding n-3 PUFA significantly altered the proportions of specific fatty-acid classes. For example, all marine-oil-rich diets were associated with increases in total monounsaturated fatty acids in TPL (p < 0.05), and with decreases in total saturates in TAG (p < 0.05). Predictably, the n-3 PUFA enriched regimens significantly increased the cardiac content of n-3 PUFA and decreased that of n-6 PUFA, although the extent varied among the diets. As a result, n-6/n-3 ratios were significantly lower in all myocardial lipid classes of marine-oil-fed guinea pigs. Analyses of the profiles of individual PUFA indicated that quantitatively, the fatty acids of the three marine oils were metabolized and/or incorporated into TPL, TAG and FFA in a diet-specific manner. In animals fed MO-enriched diets in which eicosapentaenoic acid (EPA) > docosahexacnoic acid (DHA), ratios of DHA/EPA in the hearts were 1.2, 2.2 and 1.5 in TPL, TAG and FFA, respectively. In SLO-fed guinea pigs in which dietary EPA approximately DHA, ratios of DHA/EPA were 0.9, 3.4 and 2.1 in TPL, TAG and FFA, respectively. Feeding NP + PLO (DHA/EPA = 4.8), resulted in values for DHA/EPA in cardiac tissue of 2.1, 10.6 and 2.9 in TPL, TAG and FFA, respectively. In the TAG and FFA, proportions of n-3 docosapentaenoic acid (n-3 DPA) were equal to or higher than EPA in the SLO- and PLO-fed animals. The latter group exhibited the greatest difference between the DHA/n-3 DPA ratio in the diet and in cardiac TAG and FFA fractions (7, 3.4 and 3.1, respectively). Quantitative analysis indicated that > or = 85% of the n-3 PUFA were in TPL, 7-11% were in TAG, and 2-6% were FFA. Specific patterns of distribution of EPA, DPA and DHA depended on the dietary oil. Both the qualitative and quantitative results of this study demonstrated that in guinea pigs, n-3 PUFA in different marine oils are metabolized and/or incorporated into cardiac lipids in distinct manners. In support of the concept that the diet-induced alterations reflect changes specifically in cardiomyocytes, we observed that direct supplementation of cultured guinea pig myocytes for 2-3 weeks with EPA or DHA produced changes in the PUFA profiles of their TPL that were qualitatively similar to those observed in tissue from the dietary study. The factors that regulate specific deposition of n-3 PUFA from either dietary oils or individual PUFA are not yet known, however the differences that we observed could in some manner be related to cardiac function and thus their relative potentials as health-promoting dietary fats.

Chapter 106 - Mutagenic Activity in Meat Samples after Deep-frying in Olive Oil: Comparison with other Oils

Relations between compositional traits and sensory qualities of French dry-cured ham

The primary aim of this study was to investigate volatile constituents for the differentiation of Chinese marinated pork hocks from four local brands, Dahongmen (DHM), Daoxiangcun (DXC), Henghuitong (HHT) and Tianfuhao (TFH). To this end the volatile constituents were evaluated by gas chromatography-mass spectrometry/olfactometry (GC-MS/O), electronic nose (E-nose) and chemometrics. A total of 62 volatile compounds were identified and quantified in all pork hocks, and 24 of them were considered as odour-active compounds because their odour activity values (OAVs) were greater than 1. Hexanal (OAV at 3.6–20.3), octanal (OAV at 30.3–47.5), nonanal (OAV at 68.6–166.3), 1,8-cineole (OAV at 36.4–133.3), anethole (OAV at 5.9–28.3) and 2-pentylfuran (OAV at 3.5–29.7) were the key odour-active compounds contributing to the integral flavour of the marinated pork hocks. According to principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) of GC-MS/O and E-nose data, the results showed that the marinated pork hocks were clearly separated into three groups: DHM, HHT, and DXC-TFH. Nine odour-active compounds, heptanal, nonanal, 3-carene, d-limonene, β-phellandrene, p-cymene, eugenol, 2-ethylfuran and 2-pentylfuran, were determined to represent potential flavour markers for the discrimination of marinated pork hocks. This study indicated the feasibility of using GC-MS/O coupled with the E-nose method for the differentiation of the volatile profile in different brands of marinated pork hocks.

This study investigated the differences in key volatile organic compounds (VOCs) and flavor characteristics between essential oils (CEOs) from cinnamon bark and leaf. The volatile compounds of essential oils extracted from Cinnamomum cassia (Xijiang) bark (CEOP) and leaf (CEOY) by hydrodistillation were identified using GC-MS. The results showed that the extraction rates of CEOP and CEOY were 1.56% ± 0.02 and 0.83% ± 0.01 (n = 3), respectively. CEOP and CEOY consisted of 45 and 50 compounds, respectively. Odor activity value (OAV) analysis indicated that cinnamaldehyde (OAV = 935), α-caryophyllene (OAV = 77), and borneol (OAV = 4) played key roles in shaping the aroma of CEOP. Meanwhile, cinnamaldehyde (OAV = 849), nerolidol (OAV = 107), and α-caryophyllene (OAV = 58) were the major contributors to the flavor of CEOY. Electronic nose (E-nose) analysis revealed that sensors W5S and W1W were important for detecting aromatic compounds. Sensory evaluation showed that CEOs differed significantly in spicy, floral, and grassy aromas. These differences may be related to the concentrations of compounds such as cinnamaldehyde, α-caryophyllene, and nerolidol, as well as their interactions with olfactory receptors such as OR2W1 and OR1D2. Cinnamaldehyde activates TRPA1 and TRPV1 to elicit the perception of spiciness. Thus, CEOP may be suitable for baked goods, and CEOY may be suitable for ice cream and beverages. In conclusion, this study provides a theoretical foundation for the precise application of CEOs as condiments in food.

As a wine-producing region in China, Xinjiang’s ecological conditions endow grapes with distinctive flavor potential. However, systematic research on volatile compounds in wines from Vitis amurensis Rupr. varieties in this region remains limited. Therefore, wines from four Xinjiang Vitis amurensis varieties (‘Shuanghong’, ‘Zuoyouhong’, ‘Xuelanhong’, and ‘Beibinghong’) were analyzed using high-performance liquid chromatography (HPLC), headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS), electronic nose (E-nose), odor activity value (OAV) calculation, and multivariate analysis. Physicochemical parameters, organic acids, volatile organic compounds (VOCs), and OAVs were determined. Results showed significant differences in physicochemical properties among the varieties, potentially correlating with wine mouthfeel. Beibinghong wine contained the highest total VOC concentration. Among 64 identified VOCs, 37 had OAVs ≥ 1. Multivariate analysis identified 14 key differential volatile compounds (VIP ≥ 1, p < 0.05) responsible for flavor differences between varieties, with each variety exhibiting distinct key compounds. E-nose analysis effectively distinguished the aroma profiles of the four wines. This study elucidates the chemical and volatile compound characteristics of wines from Xinjiang Vitis amurensis varieties, providing a theoretical foundation for research on their flavor profiles. It also aids in selecting Vitis amurensis varieties for cultivation and supports the development of distinctive regional wines in Xinjiang.