Effect of sampling fat location and cooking on fatty acid composition of beef steaks

To investigate the impact of sampling fat location and cooking on fatty acid composition of beef steaks, 21 raw steaks from crossbred steers were dissected to obtain outer (OSC) and inner subcutaneous fat (ISC), seam fat, marbling, and lean muscle. Twenty-one cooked steaks were dissected to obtain OSC, ISC, seam fat, surface and inner muscle. Trans-vaccenic acid and c9, t11-CLA percentages were lower (P < 0.05) in lean muscle than subcutaneous (s.c.) fat or marbling. Monounsaturated: saturated fatty acid ratios were lower (P < 0.05) in seam fat and marbling than s.c. fat or lean muscle. Linoleic and linolenic acid levels were highest in lean muscle and longer chain n−6 and n−3 fatty acids were only detected in lean muscle. Cooking did not change fatty acid composition dramatically except that n−6: n−3 ratio in s.c. and seam fat decreased after cooking (P < 0.05).     

Changes in fatty acids and polar material of restructured low-fat or walnut-added steaks pan-fried in olive oil

The study aims to determine the influence of pan-frying on the fatty acid composition and fat content and alteration of functional restructured beef steaks. Low-fat (L, 2% fat), 20% walnut-added (W, 13% fat) and medium fat (M, 13% fat) steaks were prepared and fried in extra virgin olive oil. Pan-frying increased fat in L and W steaks and decreased it in M ones. Raw L and M steaks showed similar fatty acid profiles while W ones contained a lower percentage of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) but a higher percentage of polyunsaturated fatty acids (PUFA). The fatty acid profile of fried steaks was between that of the raw steaks and olive oil. Several fatty acids (g fatty acid/100 g edible steaks) were affected (p < 0.001) by the frying × meat-formulation interaction. Linoleic and linolenic acid contents did not decrease in fried W steaks, but decreased (p < 0.05) when data were expressed on a dry matter basis.Frying increased SFA, MUFA and ω-6 PUFA contents in L samples while it decreased SFA and increased ω-6 PUFA in M steaks. Before and after frying, W steaks had atherogenic and thrombogenic indexes at least three times lower than their counterparts. Both indexes decreased in fried L samples while only the AI in M ones. Polar material content (PM) increased only in L samples. No relevant differences were found between PM of the fried steaks and that of their corresponding used oils. Results suggest that pan-frying improves the fatty acid composition of L and M steaks with minor changes in PM. The high retention of lipids observed in the W samples permits consumption of ω-3 PUFA- and ω-6 PUFA-enriched meat with a very low content of alteration compounds.     

Effect of varying salt and fat levels on the sensory quality of beef patties

The interactive effects of varying levels of salt and fat on the sensory and physiochemical properties of beef patties were investigated. Twenty beef patties with varying levels of fat (30% 40% 50% 60% w/w) and salt (0.5%, 0.75% 1.0% 1.25% 1.5% w/w) were manufactured. All samples were assessed instrumentally for colour, moisture, fat, cooking loss and texture profile analysis. Sensory consumer evaluation was conducted using 25 consumers. The consumers rated each coded product, in duplicate, in terms of colour, texture, tenderness, juiciness, salt, taste, meat flavour, off flavour and overall acceptability. The data indicate that the most consumer acceptable beef patty was that containing 40% fat with a salt level of 1%. This is a 20% decrease in fat and a 50% decrease in salt levels when compared to commercial patties available in Ireland and the UK.     

Inclusion of blended lipid solutions as functional ingredients to alter the fatty acid profile of beef patties

Beef patties formulated to contain beef fat, plant oil, and a rosemary extract to increase unsaturated fatty acid content and maintain desirable sensory attributes were compared to control beef patties formulated without plant oils. Treatment patties were formulated to a fat content of 10% or 20% by combining beef trimmings (6% fat) with 4% or 14% addition of a lipid blend. Blends contained 57% beef tallow, 0.3% rosemary extract, and 43% of high oleic safflower oil (SO), olive oil (OO), or corn oil (CO). Lipid oxidation, as measured by TBA values, of treatment patties were similar to control patties after 0 and 3 d of refrigerated (2 °C) storage and up to 56 d of frozen (-10 °C) storage. Cooked lipid blend patties having a fat content of 10% or 20% were similar to or higher than control patties for juiciness and were no different for other sensory attributes evaluated. At fat levels of 10% or 20%, oleic acid (18: 1) in cooked SO patties (46.1% and 50.3%, respectively) and OO patties (43.8% and 48.1%, respectively) was higher than the control (37.3% and 37.6%, respectively). Unsaturated to saturated fatty acid ratios at the 10% or 20% fat levels were higher in SO (1.37 and 1.60, respectively) and CO (1.40 and 1.48, respectively) patties than the control (0.97 and 0.94, respectively). Beef patties manufactured with varying lipid blends increased unsaturated fatty acid content and were similar in physical characteristics and sensory attributes of all beef patties formulated without lipid blends. PRACTICAL APPLICATION: The development of healthier beef products that will be more appealing to consumers has long been an industry goal. The authors believe that lipid blends such as the one used in this study could be used to create such products, not only in the form of beef patties, but any number of processed meat products. Because the materials and equipment used to create the lipid blends in this study are widely available, their incorporation into meat products would represent a small capital investment. This is an important factor in bringing a reasonably priced, healthier product to consumers.     

Evaluation of the quality of olive oil using fatty acid profiles by direct infusion electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry is used to predict the olive oil quality according to European Union marketing standards. Samples were 1:50 diluted in an alkaline 85:15 (v/v) propanol/methanol mixture and directly infused into the electrospray ionization source of an ion trap mass spectrometer. The establishment of ratios of the peak abundances of the free fatty acids followed by linear discriminant analysis was employed to predict the olive oil quality grade. In addition, using multiple linear regression and partial least-squares regression, the percentages of extra virgin and virgin olive oils in binary mixtures were predicted with 5–11% average prediction errors.     

Effect of lutein,sesamol, ellagic acid and olive leaf extract on the quality and shelf-life stability of packaged raw minced beef patties

The effects of lutein (100 and 200 μg/g muscle), sesamol (250 and 500 μg/g muscle), ellagic acid (300 and 600 μg/g muscle) and olive leaf extract (100 and 200 μg/g muscle) on total viable counts (TVCs), lipid oxidation (thiobarbituric acid-reactive substances, TBARS), colour, oxymyoglobin oxidation, pH, water-holding capacity (WHC), sensorial properties of raw beef patties (M. longissimus thoracis et lumborum) stored in modified atmosphere packs (80% O₂:20% CO₂) (MAP) aerobically at 4 °C for up to 8 and 12 days, respectively, were examined. All the nutraceuticals reduced (P < 0.001) TVCs. The addition of sesamol, ellagic acid and olive leaf extract reduced (P < 0.001) TBARS in raw beef patties in both packaging systems. Sesamol addition to beef resulted in lower (P < 0.01) a* redness values and increased oxymyoglobin oxidation. Conversely, lutein and olive leaf extract reduced (P < 0.001) oxymyoglobin oxidation relative to the control. The graded addition of ellagic acid and olive leaf extract improved (P < 0.001) WHC.     

Fatty acid profile of olive oil extracted from irradiated and non-irradiated olive fruits

Syrian Kaissy cv olive fruit (SKOF) was irradiated (0, 1, 2, and 3 kGy). Oils were extracted from irradiated and un-irradiated olive fruits. Fatty acid profiles of Syrian Kaissy cv olive oil (SKOO) were measured by gas chromatography immediately after irradiation and after 6, 12, 24, and 36 months of storage. Results of the study showed that composition of fatty acids of SKOO were determined as palmitic (C16:0) (14.69%), palmitoleic acid (C16:1) (1.18%), stearic (C18:0) (2.19), oleic (C18:1) (68.94%), linoleic (C18:2) (12.22%), and linolenic acid (C18:3) (0.79%). The fatty acid composition of SKOO contains a healthy mixture of all the types of saturated mono-unsaturated and poly-unsaturated fatty acids. The data showed an increase (p < 0.05) in the percentage of the total saturated fatty acids and decrease (p < 0.05) in the percentage of the total unsaturated fatty acids of SKOO during storage. In general, there were no significant (p > 0.05) differences in fatty acids compositions of both oils extracted from irradiated and un-irradiated SKOF.     

Effect of low dose gamma irradiation on beef quality and fatty acid composition of beef intramuscular lipid

Eight Chinese Yellow Cattle semitendinous muscles were irradiated using a (60)Co irradiation source (with the dose of 1.13, 2.09, or 3.17kGy) and stored (0 day or 10 days at 7°C) to estimate fatty acids change of neutral lipid (NL), polar lipid (PL) and total lipid (TL) fractions, and the beef quality change. Total saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) increased with irradiation, ratios of MUFA to SFA did not change in TL. Whilst, total polyunsaturated fatty acid (PUFA) reduced with irradiation, which resulted in PUFA to SFA ratio decreased in TL (0 day or 10 days). Purge loss and 2-thiobarbituric acid reactive substances values increased with irradiation (from 0 to 3.17kGy) at 0 day, but these values were lower with irradiation at 10 days. Total bacterial counts decreased proportionally with irradiation dose increasing from 0 to 3.17kGy. It can be concluded that fatty acid profiles in beef changed with irradiation; however, fatty acid profiles did not change much at 3.17kGy compared with 1.13 or 2.09kGy, and the beef quality were most acceptable at the dose of 3.17kGy, thus, low dose of about 3kGy gamma irradiation was recommended to apply in fresh beef preparation.     

Stability of avocado oil during heating: Comparative study to olive oil

The stability of the saponifiable and unsaponifiable fractions of avocado oil, under a drastic heating treatment, was studied and compared to that of olive oil. Avocado and olive oil were characterised and compared at time 0 h and after different times of heating process (180 °C). PUFA/SFA (0.61 at t = 0) and ω-6/ω-3 (14.05 at t = 0) were higher in avocado oil than in olive oil during the whole experiment. Avocado oil was richer than olive oil in total phytosterols at time 0 h (339.64; 228.27 mg/100 g) and at 9 h (270.44; 210.30 mg/100 g) of heating. TBARs was higher in olive oil after 3 h, reaching the maximum values in both oils at 6 h of heating treatment. Vitamin E was higher in olive oil (35.52 vs. 24.5 mg/100 g) and it disappeared earlier in avocado oil (at 4 vs. 5 h). The stability of avocado oil was similar to that of olive oil.     

Application of partial least square regression to differential scanning calorimetry data for fatty acid quantitation in olive oil

A chemometric approach based on partial least (PLS) square methodology was applied to unfolded differential scanning calorimetry data obtained by 63 samples of different vegetable oils (58 extra virgin olive oils, one olive and one pomace olive oil, three seed oils) to evaluate fatty acid composition (palmitic, stearic, oleic and linoleic acids, saturated (SFA), mono (MUFA) and polysaturated (PUFA) percentages, oleic/linoleic and unsaturated/saturated ratios).     

Effect of age and cut on cooking loss, juiciness and flavour of South African beef

The juiciness and flavour characteristics of 15 aged primal beef cuts of electrically stimulated carcasses, from three different age groups, were assessed (n=61). Cooking losses were determined and proximate analyses (moisture, fat, nitrogen and ash) were performed. Tender cuts were cooked by a dry heat method, and less tender cuts were cooked by moist heat methods. A trained panel (n=10) evaluated sensory quality characteristics including initial and sustained juiciness, aroma and flavour. Flavour intensity was the biggest discriminant between the three age groups and declined with an increase in age. Initial impression of juiciness decreased with increased age of the animal and cooking losses increased nonlinearly with age, irrespective of the muscle. In contrast sustained juiciness increased with increased age. Cuts cooked according to a dry heat cooking method were reported juicier (both initial and sustained) than those cooked by moist heat methods.     

A comprehensive study of hazelnut oil composition with comparisons to other vegetable oils,particularly olive oil.

Crude and refined hazelnut oils from different countries were characterised by major and minor compounds. Fatty acids, triacylglycerides, waxes, sterols, methyl-sterols, terpenic and aliphatic alcohols, tocopherols, tocotrienols and hydrocarbons were identified and quantified by gas chromatography and high-performance liquid chromatography. The levels of these chemical compounds in hazelnut oils together with the equivalent carbon numbers and triacylglyceride carbon numbers, were compared with the results of analyses of samples of other vegetable oils. The statistical procedure of cluster analysis was used to characterise hazelnut oils versus other edible oils.     

Classification of Turkish olive oils with respect to cultivar,geographic origin and harvest year,using fatty acid profile and mid-IR spectroscopy

Fatty acid composition and mid-infrared spectra of olive oils in combination with chemometric techniques were used in the classification of Turkish olive oils with respect to their varieties, growing location and harvest year. In particular, olive oil samples belonging to five different cultivars were obtained from the same orchard in the middle part of Aegean region and two of these varieties were also received from another orchard in northern part of the same region of Turkey in two consecutive harvest years. Evaluation of nine different fatty acid compositions with principal component analysis revealed clear differentiation with respect to variety, geographical origin and harvest year. On the other hand, mid-infrared spectra also achieved varietal and seasonal discrimination to some extent, but differentiation is not as clear as that obtained using fatty acid compositions.     

Blends of olive oil and sunflower oil: Characterisation and olive oil quantification using fatty acid composition and chemometric tools

A method capable of recognising the percentage of olive oil in a blend is required to verify whether its labelling complies with the statements set out by the Commission Regulation (EC) No. 1019/2002. In this study an analytical methodology was developed in order to define blends of olive oil and sunflower oil, which contain 50% of olive oil, compared to blends with 40% and 60% of it, respectively. Methyl esters of fatty acids were analysed by GC–FID and processed through chemometric tools (PCA, TFA, SIMCA and PLS). A strong differentiation of blends according to the amount of olive oil contained and a quantification model with a standard error of prediction of 1.51% were obtained. As this issue represents a significant analytical challenge, variability associated with the fatty acid composition of olive oil was first studied.     

Effect of sex and age on bovine muscle and adipose fatty acid composition and stearoyl-CoA desaturase mRNA expression

The objective of the study was to investigate the effects of sex and slaughter age on the fatty acid (FA) composition and stearoyl-CoA desaturase gene expression in muscle and adipose tissue. Twenty-four Charolais × Simmental crossbred bulls and heifers were raised under similar conditions and slaughtered at 14 or 18 months of age. The total amount of FA in muscle increased markedly in older animals with higher contents of monounsaturated FA (MUFA) in heifers than bulls. The proportions of MUFA and desaturation indices were higher in heifers, whereas polyunsaturated FA were higher in bulls in both muscle and subcutaneous adipose tissue. The results of this study demonstrated sex-dependent differences in the FA composition of muscle and subcutaneous adipose tissue from cattle slaughtered at different ages. The expression of the stearoyl-CoA desaturase gene was higher in the adipose tissue of heifers compared to bulls, and its variation partly contributed to sex- and age-differences in the FA composition of bovine adipose tissue.     

Effects of pan-frying in margarine and olive oil on the fatty acid composition of cod and salmon

Effects on the fatty acid composition of cod (Gadus morhua) and salmon fillets (Salmo salar) after pan-frying in margarine and olive oil were determined. The fatty acids of the margarine used were 55.5% saturated (SFA), 33.0% mono-unsaturated (MUFA) and 11.5% polyunsaturated (PUFA). The olive oil used contained 15.4% SFA, 76.1% MUFA and 8.5% PUFA. Using margarine or olive oil increased the SFA and MUFA percentages, respectively, in both species. For cod fillets (lean), pan-frying increased the fat content (0.55–4.15 g/100 g and 0.55–2.30 g/100 g before and after pan-frying, with margarine and olive oil, respectively), whereas, for salmon fillets (fat), it decreased (13.91 to 10.57 g/100 g and 15.35 to 12.95 g/100 g before and after pan-frying with margarine and olive oil, respectively). In conclusion, the culinary fat selection affects the total fatty acid content and composition of the prepared fish fillet.     

Detection of fresh palm oil adulteration with recycled cooking oil using fatty acid composition and FTIR spectral analysis

There is a growing concern over the food safety issue related to increased incidence of cooking oil adulteration with recycled cooking oil (RCO). The objective of this study was to detect fresh palm olein (FPO) adulteration with RCO using fatty acid composition (FAC) and Fourier-transform infrared spectroscopy (FTIR) spectral analyses combined with chemometrics. RCO prepared in the laboratory was mixed with FPO in the proportion ranged from 1% to 50% (v/v) to obtain the adulterated oil samples (AO). FACs for FPO, RCO, and AO were determined using gas chromatography equipped with a flame ionization detector (GC-FID). The compositions of most fatty acids in RCO lied within the normal ranges of Codex standard, except for C8:0, C10:0, C11:0, C15:0, trans C18:1, and polyunsaturated fatty acids (PUFAs), C20:5. PUFAs showed a consistent decreasing trend with increasing magnitude of change with respect to increasing adulteration level and thus might be a good indicator for detecting FPO adulteration with RCO. The evaluation parameters (coefficient of determination, root mean standard error) of the FTIR-partial least square (PLS) model of palm oil adulteration with recycled oil are R² = 0.995 and 3.25, respectively. For FTIR spectral analysis, the distinct variations in spectral regions and aberrations in characteristic bands between FPO and RCO were observed. The optimized PLS calibration model developed from normal spectral of the combined region at 3602–3398, 3016–2642, and 1845–650 cm^?1 overpredict the adulteration level. On the other hand, the discriminant analysis classification model was able to classify the FPO and AO into two distinct groups. Improvement of the principles of combined techniques in authenticating AO from fresh oil is beneficial as a guideline to detect adulteration in cooking oil.     

Effect of gamma-ray irradiation on the fatty acid profile of irradiated beef meat

The effect of γ-ray irradiation on the fatty acid profile of beef meat was examined at doses of 2.5, 5.0, 7.5, 10.0 and 15.0 kGy by means of ¹H NMR spectroscopy. NMR results revealed a clear trend toward an increase in the amount of saturated fatty acids and a decrease in the amount of polyunsaturated fatty acids in the triacylglycerol composition of the irradiated samples compared to the unirradiated sample with increasing the irradiation dose.