Effect of storage conditions on lipid components and color of Mugil cephalus processed roes

The salted and semidried mullet (Mugil cephalus) ovary product (bottarga) is proposed as an important source of the long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid, and docosahexaenoic acid. In this work, we investigated the extent of lipid oxidation and browning of grated bottarga samples during 7 mo of storage at -20 °C, 2 to 3 °C in the absence of light, and at room temperature in the presence or absence of light. Modifications of the levels of total choline (as index of phospholipid breakdown), total sugars, and free amino acids such as lysine, methionine, and tryptophan (involved in nonenzymatic browning) were also studied at different storage conditions. Storage of bottarga did not significantly affect the n-3 PUFA and cholesterol levels with respect to the control; nevertheless, a significant hydroperoxide increase was observed during 7 mo in bottarga samples at all the storage conditions, while low malondialdeyde levels were measured. Samples placed at room temperature in the absence and in the presence of light showed over time a marked browning process, lipid breakdown, a sensible decrease in the levels of total sugars, tryptophan, and methionine with respect to control and samples stored at -20 °C and 2 to 3 °C. The resistance against the oxidation of the isolated bottarga lipids was also assessed in dry state at several temperatures (37, 75, and 140 °C). PRACTICAL APPLICATION: We evaluated the change in lipid compounds and color of dried and salted mullet roes under different storage conditions. The obtained results suggest the importance of the low temperatures to preserve the nutritional properties of this fish product during long storage.     

Lipid components and water soluble metabolites in salted and dried tuna (Thunnus thynnus L.) roes

The salted and dried product of tuna roe (bottarga) is a seafood characteristic of the Mediterranean area and exported all over the world. Samples of bottarga from bluefin tunas (Thunnus thynnus, L.) caught in the southwest Mediterranean sea were analysed. The samples were characterised by high content of marine wax esters (55–67 mol% of lipid classes), of docosahexaenoic (22:6 n-3, 25 w%) and oleic (18:1 n-9, 19 w%) fatty acids. Cholesterol was detected as 7–9 w% of lipids. Free fatty acids, index of lipid hydrolysis, represented 32–39 mol% over total fatty acids. Among metabolites, nutrients as taurine, nicotinamide and β-alanine, were found. The microflora comprised staphylococci, enterococci (2.2 log₁₀ CFU/g) and lactic acid bacteria (3 log₁₀ CFU/g). The food-borne pathogens Staphylococcus aureus, Listeria monocytogenes and Salmonella spp. were not detected. These findings indicate tuna bottarga as valuable source of nutrients.     

Effects of high pressure treatment and temperature on lipid oxidation and fatty acid composition of yak (Poephagus grunniens) body fat

Effects of high-pressure treatment (100 MPa to 600 MPa) on lipid oxidation and composition of fatty acids in yak body fat at 4 °C and 15 °C were investigated for up to 20 days storage. 400 and 600 MPa treatments increase the level of thiobarbituric acid-reactive substances (TBARS) 335% and 400% (p < 0.05), respectively. Composition analysis shows that 600 MPa treatment induces a lower (p < 0.05) percentage of polyunsaturated fatty acids, and C22:6 decreased significantly. A significant decrease in PUFA/SFA and n-6/n-3 PUFA values was observed at the end of storage. Samples treated at the lower pressures gave good sensory acceptability. It is concluded that a higher-pressure treatment is important in catalyzing lipid oxidation and the evolution of fatty acids in pressure-treated yak body fat.     

Colour,lipid and protein stability of Rhea americana meat during air- and vacuum-packaged storage: Influence of muscle on oxidative processes

Physicochemical characteristics and oxidative stability during storage were determined in Gastrocnemius pars interna (GN) and Iliofiburalis (IF) muscles of Rhea americana. Glycolytic potential (GP) and pH decline of muscles were measured within the first 24 h post mortem. Colour, lipid and protein stability were determined during storage of meat, i.e. 5 days under air-packaging at 4 °C, or 28 days under vacuum-packaging at 4 °C. In parallel, anti-oxidant status of muscles was estimated by measuring α-tocopherol content and anti-oxidant enzyme activities (superoxide dismutase and catalase), while pro-oxidant status was evaluated by determining haeminic iron and long chain fatty acids (especially polyunsaturated fatty acids). The ultimate pH was similar in both muscles, but the GP value was significantly higher in IF than in GN muscle. Haeminic iron and alpha-tocopherol content differed between muscles, with 30% more haeminic iron (p < 0.05) and 134% more alpha-tocopherol (p < 0.001) in IF than GN muscle. The IF muscle presented higher lipid content and lower PUFA/SFA ratio (polyunsaturated fatty acids/saturated fatty acids) than GN muscle. With storage under air-packaging, lipid and protein oxidation of rhea muscles increased up to 275% and 30%, respectively. This increase was more rapidly and marked in IF muscle. The IF also showed high level of metmyoglobin accumulation after 3 days of storage (47%) and was rejected by 1 consumer out of 2 in sensorial analysis. Under vacuum-packaging, both muscles showed a high stability of colour and no oxidation of lipids and proteins.     

The effects of gender,age and region on macro- and micronutrient contents and fatty acid profiles in the muscles of roe deer and wild boar in Mecklenburg-Western Pomerania (Germany)

Samples of M. longissimus were collected from a total of 203 feral roe deer (n = 118) and wild boar (n = 85) in two regions of Mecklenburg-Western Pomerania (Germany). The muscle lipid saturated fatty acid proportions of roe deer and wild boar ranged between 33 and 49 g/100 g total fatty acids and 31 and 35 g/100 g total fatty acids, respectively. The total n − 3 PUFA proportions in roe deer muscle varied between 8.0 and 14 g/100 g fatty acids, and in wild boar muscle between 2.6 and 6.0 g/100 g fatty acids. The major vitamin E homologue, α-tocopherol, was determined to be between 5.8 and 13.1 mg/kg in roe deer muscles. Lower levels between 1.2 and 4.7 mg/kg were measured in wild boar muscles. The iron and zinc concentrations in roe deer and wild boar muscle ranged from 26.3 to 33.9 mg/kg and from 17.0 to 21.7 mg/kg, and from 13.6 to 39.3 mg/kg and 18.1 to 31.9 mg/kg, respectively.     

Effect of processing on amine formation and the lipid profile of cod (Gadus morhua) roe

The processing of fish roe leads to changes in its chemical composition, the extent of which depends on the techniques and additives employed. This study aimed to investigate the effects of ripening temperature and the use of sodium benzoate and citric acid on the quality of ripened cod roe, with respect to the contents of volatile base nitrogen (VBN), trimethylamine (TMA), biogenic amines (BA) and on the lipid composition. In comparison with fresh roes, ripened roes presented higher contents of VBN, TMA, BA and the proportion of free fatty acids regardless of the temperature and additives used during the ripening process. The greatest increases were observed in the samples ripened at 17 °C without additives, in which histamine was detected at 8.8 mg/100 g. A low ripening temperature was the main factor responsible for minimising changes in the cod roe composition. The addition of sodium benzoate as a preservative or citric acid to decrease the pH value had a significant effect in maintaining the quality of the cod roes, mainly at high ripening temperature.     

Characterization of lipid oxidation products in quinoa (Chenopodium quinoa)

The oxidative stability of lipids in processed quinoa was investigated in this study. Ground quinoa was subjected to accelerated aging for 30 days at 25, 35, 45, and 55 °C. Three samples were removed from each temperature treatment every 3 days. Free fatty acids, conjugated diene hydroperoxides, and hexanal were used as indicators of lipid oxidation. Storage time and temperature had significant effects (p ? 0.05) on all three parameters, while the interaction between storage time and temperature was not significant for conjugated diene hydroperoxides produced. The results from these tests suggest that quinoa lipids are stable for the period of time studied. With vitamin E as a naturally antioxidant occurring abundantly in quinoa, the potential for quinoa to be a new oilseed could be enhanced. This study provided some preliminary information on the oxidative stability of quinoa.     

Impact of free fatty acid concentration and structure on lipid oxidation in oil-in-water emulsions

Free fatty acids are strong prooxidants in both bulk and emulsified oils. Addition of oleic acid to an oil-in-water emulsions increased lipid hydroperoxide and hexanal formation at free fatty acid concentrations as low as 0.1% of the lipid. The prooxidant effect of free fatty acids was dependent on fatty acid type with lipid oxidation rates being in the order of linolenic < linoleic < oleic. There were no significant differences in lipid oxidation rates when free fatty acid isomers with cis or trans double bonds were compared. The prooxidant activity of the free fatty acids was postulated to be due to their ability to attract prooxidant metals as well as co-oxidise the triacylglycerol in the oil. Overall, these results show that the oxidative stability of oil-in-water emulsions is strongly linked to both the concentration and type of free fatty acids present.     

Fatty acid composition of minced meat,longissimus muscle and omental fat from Small East African goats finished on different levels of concentrate supplementation

Effects of supplementing Small East African (SEA) goats with concentrate diets on fatty acids composition of minced meat, M. longissimus dorsi (LD) and omental fat were assessed using 23 animals (14.5 months old and 20.1 kg body weight). Goats were subjected to four levels of concentrate supplementation: ad libitum concentrate allowance (T100), 66% (T66), 33% (T33) and 0% (T0) of ad libitum concentrate allowance. All goats were slaughtered after 90 days of experimental period. Minced meat from concentrate-supplemented goats had higher (P < 0.05) proportions of unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA) and desirable fatty acid (DFA) than that of non-supplemented ones (T0). Minced meat from T00 and T66 goats had similar proportions of polyunsaturated fatty acids (PUFA) and n-6 PUFA that were higher (P < 0.05) than that of other dietary groups. There was limited variation in fatty acids composition of LD attributable to concentrate supplementation. Trans-vaccenic and linoleic acids were in higher (P < 0.05) proportion in omental fat from concentrate-supplemented goats whereas margaric and arachidonic acids were in higher (P < 0.05) proportion in omental fat from non-supplemented goats. Overall, LD was associated with PUFA, omental fat with saturated fatty acids (SFA), minced meat with MUFA. It is concluded that finishing SEA goats on concentrate diets will increase the proportion of DFA in meat from them. In addition, the proportion of PUFA in meat from such goats will peak at concentrate supplementation equivalent to 66% of their ad libitum intake. Consumers should avoid high intake of internal fat due to their richness in SFA.     

Effect of a supplementation of Euphorbia heterophylla on nutritional meat quality of Guinea pig (Cavia porcellus L.)

The aim of the present work was to study the effect of dietary supplementation of Euphorbia heterophylla on the quality of the Guinea pig meat. Forty guinea pigs were divided into two groups fed ad libitum during 46 days a Panicum maximum diet (Panicum diet) or a mixed diet (75% Panicum maximum + 25% Euphorbia heterophylla) (Paneuphorbia diet) to compare their effects on performances and on the composition of guinea pig tissues and carcass. Daily weight gain, liver weight, carcass yield, and the lipid content of both the carcass and the perirenal fat were significantly increased by the Paneuphorbia diet. Feeding Paneuphorbia diet increased (P < 0.05) the n-3 PUFA content in perirenal fat, muscle, liver and in the carcass and decreased (P < 0.05) the n-6/n-3 ratios in all these tissues and the carcass. In conclusion, this study shows that Euphorbia heterophylla is a source of n-3 fatty acids which can improve significantly the n-3 PUFA content of Guinea pig meat and carcass.     

Composition and antioxidant capacity of low-salt meat emulsion model systems containing edible seaweeds

The study was designed to determine the influence of the addition of edible seaweeds, Sea Spaghetti (Himanthalia elongata), Wakame (Undaria pinnatifida), and Nori (Porphyra umbilicalis), on fatty acid composition, amino acid profile, protein score, mineral content and antioxidant capacity in low-salt meat emulsion model systems. The addition of seaweeds caused an increase (P < 0.05) in n-3 polyunsaturated fatty acids (PUFA) and a decrease (P < 0.05) in the n-6/n-3 PUFA ratio. The thrombogenic index significantly decreased (P < 0.05) in Nori and Wakame meat samples. Meat systems made with added seaweeds had lower (P < 0.05) sodium contents than control samples. In general, addition of seaweeds to products increased (P < 0.05) the concentrations of K, Ca, Mg and Mn. The presence of Nori caused an increase (P < 0.05) in levels of serine, glycine, alanine, valine, tyrosine, phenylalanine and arginine, whereas Wakame and Sea Spaghetti produced no significant changes in amino acid profiles in the model systems. The inclusion of Sea Spaghetti increased the sulphur amino acid score by 20%. The added seaweeds supplied the meat samples with soluble polyphenolic compounds, which increased the antioxidant capacity of the systems. The polyphenol supply and antioxidant increase were greatest (P < 0.05) in the samples containing Sea Spaghetti.     

Chemical and sensory quality changes of fish fingers,made from mirror carp (Cyprinus carpio L., 1758), during frozen storage (−18 °C)

The effects of frozen storage at −18 °C on the chemical and sensory qualities of fish fingers produced from unwashed and washed mirror carp (Cyprinus carpio) mince were investigated. The amounts of moisture, crude protein, lipid, crude ash, ω3 polyunsaturated fatty acids (PUFA ω3), and ω6 polyunsaturated fatty acids (PUFA ω6) in fish fingers produced from unwashed mince (UWF) were found to be 68.50%, 15.5%, 6.00%, 2.20% 2.31%, and 55.2%, respectively, while they were found to be 70.23%, 10.8%, 2.14%, 1.80%, 2.28%, and 54.6%, respectively, in carp fingers produced from washed mince (WF). The thiobarbituric acid value (TBA, mg malonaldehyde/kg) was found to be significantly higher in mince of WF than in mince of UWF and increased significantly during frozen storage in both the mince of UWF and WF (p < 0.05). A significant decrease in pH was obtained throughout the washing treatment (p < 0.05). There were no significant differences of pH in either the mince of UWF or WF between the beginning and end of the storage periods (p > 0.05), whereas a sharp increase was observed in the fourth month in both groups. The protein solubilities of the mince of both UWF and WF decreased significantly throughout the storage periods (p < 0.05). Sensory parameters of colour, odour, flavour, and general acceptability for both groups decreased during the frozen storage period (p < 0.05) but were still within acceptable limits. It was also concluded that mirror carp was a good source for fish fingers and that product could be stored for five months in a frozen state without undesirable changes of sensory and chemical qualities.     

Effect of cooking methods on fatty acids,conjugated isomers of linoleic acid and nutritional quality of beef intramuscular fat

The effect of boiling, microwaving and grilling on the composition and nutritional quality of beef intramuscular fat from cattle fed with two diets was investigated. Longissimus lumborum muscle from 15 Alentejano young bulls fed on concentrate or pasture was analyzed. Cooking losses and, consequently, total lipids, increased directly with the cooking time and internal temperature reached by meat (microwaving > boiling > grilling). The major changes in fatty acid composition, which implicated 16 out of 34 fatty acids, resulted in higher percentages in cooked beef of SFA and MUFA and lower proportions of PUFA, relative to raw meat, while conjugated linoleic acid (CLA) isomers revealed a great stability to thermal processes. Heating decreased the PUFA/SFA ratio of meat but did not change its n−6/n−3 index. Thermal procedures induced only slight oxidative changes in meat immediately after treatment but hardly affected the true retention values of its individual fatty acids (72–168%), including CLA isomers (81–128%).     

Evaluation of lipid oxidation in spaghetti pasta enriched with long chain n−3 polyunsaturated fatty acids under different storage conditions

This study investigated lipid oxidation in spaghetti enriched in long chain n−3 polyunsaturated fatty acids (LC n−3 PUFA) by the addition to semolina of an integrator containing eicosapentaenoic acid and docosahexaenoic acid. Two oxidative parameters were evaluated: peroxide value (PV), to assess primary oxidation and oxidised fatty acids to quantify secondary oxidation products. Functional spaghetti had a shelf life comparable to control pasta. LC n−3 PUFA were not significantly implicated in the onset of oxidation in spaghetti stored under daylight and accelerated oxidation in a laboratory heater. Storage decidedly affected shelf life: PV in functional spaghetti increased from 7.1 to 43.4 meq O₂/kg of fat under light exposure over 12 months, and from 7.1 to 16.2 meq O₂/kg under accelerated ageing at 55 °C for 27 days, reproducing about 18 months at room temperature. Oxidised fatty acids increased in fortified spaghetti from 4.8 to 13.8 g/100 g of fat under light exposure over 12 months and from 4.8 to 7.8 g/100 g of fat at 55 °C in 27 days. The high sensitivity of spectrophotometric and chromatographic analytical methods permitted the evaluation of primary and secondary oxidative derivatives in small amounts of fat.     

Dietary olive cake reduces the oxidation of lipids,including cholesterol,in lamb meat enriched in polyunsaturated fatty acids

Over 40 days, lambs were fed: concentrate (C), concentrate containing 20% linseed (L), concentrate containing 35% olive cake (OC), or concentrate containing 10% linseed and 17% olive cake (OCL). The polyunsaturated fatty acids (PUFA) and peroxidation index (PI) in phospholipids were increased by the L and OCL treatments (P = 0.007 and P = 0.003, respectively). The OC and OCL diets increased the concentration of tocopherol in muscle (P < 0.001). Compared to the OC and OCL diet, the L diet increased fatty acid oxidation, measured as conjugated dienes (CD; P = 0.003), peroxides (PV; P < 0.001) and TBARS (P = 0.002) in minced muscle over 11 days of storage in high-oxygen atmosphere. Also, the L diet increased (P < 0.001) the levels cholesterol oxidation products (COPs). In conclusion, feeding olive cake improved the oxidative stability of lamb meat and the combination of olive cake and linseed improved the fatty acid composition of meat without compromising its oxidative stability.     

The effect of replacing dietary fish oil with canola oil on fatty acid composition and expression of desaturase and elongase genes in Jade Tiger hybrid abalone

This study investigates the effect of graded substitution of dietary fish oil (FO) with canola oil (CO) on fatty acid composition and expression of Δ-6 desaturase and elongase 2 genes in the muscle of Jade Tiger hybrid abalone. The control diet contained 1.5% FO supplement (0% CO). Four other diets contained FO/CO in ratios of 3:1 (CO 25%), 1:1 (CO 50%), 1:3 (CO 75%) and 100% CO. The result demonstrated that abalone fed the diets supplemented with 25% and 50% CO showed similarly high levels of total omega-3 polyunsaturated fatty acid (n-3 PUFA), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) (P < 0.05) as the 0% CO group. The highest levels of total PUFA and total monounsaturated fatty acids were found in the 100% CO group (P < 0.05). The results also showed that Δ-6 desaturase and elongase 2 gene expression was increased in a graded manner by increasing dietary CO (P < 0.05). It was concluded that replacement of FO by CO at the levels of 25-50% can improve the contents of health-benefiting EPA and DHA in abalone.     

Variations in lipid and fatty acid contents in different body parts of Black Sea whiting,Merlangius merlangus euxinus (Nordmann, 1840)

Whiting is a commercially important fish species of the world. This study demonstrates monthly variations in lipid and fatty acid (FA) contents of muscle, liver and roes of Black Sea whiting, Merlangius merlangus euxinus. Significant changes occurred in lipid contents between months (P < 0.05) with the highest values representing in liver 33.8–64.5%. Total polyunsaturated fatty acids (PUFA) in all groups were higher than total saturated and monounsaturated FAs with significant variations between months (P < 0.05). The highest PUFA of muscles, livers and roes were 60.0, 45.9 and 50.9%, respectively. The main FA was docosahexaenoic acid (DHA) of muscle tissue and roes, while oleic acid was the major FA in livers. Although about 164–357 g in muscle tissue or 224–392 g of whiting roe are necessary to consume to cover 1 g day^?1 of eicosapentaenoic acid (EPA)+DHA for a healthy diet, only as low as 5.5–10.0 g of liver would be enough to cover the same amount of daily EPA+DHA requirement. The results indicated that whiting livers constitute a rich and underexploited source of polyunsatured FAs. Furthermore, the results may aid further research on the nutritional studies, the physiology and stock management of whiting species.     

Changes in lipid composition,fatty acid profile and lipid oxidative stability during Cantonese sausage processing

Lipid composition, fatty acid profile and lipid oxidative stability were evaluated during Cantonese sausage processing. Free fatty acids increased with concomitant decrease of phospholipids. Total content of free fatty acids at 72 h in muscle and adipose tissue was 7.341 mg/g and 3.067 mg/g, respectively. Total amount of saturated, monounsaturated and polyunsaturated fatty acids (SFA, MUFA, and PUFA) in neutral lipid exhibited a little change during processing, while the proportion of PUFA significantly decreased in the PL fraction. The main triacylglycerols were POO + SLO + OOO, PSO (P = palmitic acid, O = oleic acid, L = linoleic acid, S = stearic acid), and a preferential hydrolysis of palmitic, oleic and linoleic acid was observed. Phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the main components of phospholipids and PE exhibited the most significant degradation during processing. Thiobarbituric acid values (TBARS) increased while peroxide values and hexanal contents varied during processing.     

Volatile compounds and fatty acid profiles in commercial milk-based infant formulae by static headspace gas chromatography: Evolution after opening the packet

The evolution of the volatile compounds propanal, pentanal and hexanal, and fatty acid profiles were examined in 20 infant formula (IF) milk powders during storage at 25 °C for 70 days after their packaging was opened. Few changes were observed in the fatty acid content during storage, but significant losses were found in C18:2 n − 6 and C18:3 n − 3 for some formulae. All three volatiles increased during storage in all formulae, confirming oxidative stability decreases once packets were opened. Significant correlation (p < 0.05) was detected between hexanal content and oxidation of n − 6 PUFA, specifically C18:2 n − 6 losses, and between propanal content and oxidation of n − 3 PUFA, specifically from C18:3 n − 3 losses.     

Influence of heat processing and calcium ions on the ability of EDTA to inhibit lipid oxidation in oil-in-water emulsions containing omega-3 fatty acids

The nutritional benefits of ω-3 fatty acids make them excellent candidates as functional food ingredients if problems with oxidative rancidity can be overcome. Oil-in-water emulsions were prepared with 2% salmon oil, stabilized by 0.2% Brij 35 at pH 7. To determine the effects of heating (50–90 °C), ethylenediaminetetraacetic acid (EDTA), and calcium on the oxidative and physical stability of salmon oil-in-water emulsions, particle size, thiobarbituric acid reactive substances (TBARS), and lipid hydroperoxides were measured. The heat-processed emulsions showed no significant difference, in particle size, TBARS or hydroperoxides during storage, from unheated emulsions. Above 2.5 μM, EDTA dramatically decreased lipid oxidation in all samples. Addition of calcium to emulsions containing 7.5 μM EDTA significantly increased both TBARS and hydroperoxide formation when calcium concentrations were 2-fold greater than EDTA concentrations. These results indicate that heat-processed salmon oil-in-water emulsions with high physical and oxidative stability could be produced in the presence of EDTA.