Microbiological characteristics of pork chops and ground pork from swine fed a high monosaturated fat diet

Twelve percent high-oleic acid sunflower oil (HOSO) was included in a swine diet to increase the ratio of monounsaturated fatty acids to saturated fatty acids in pork chops and ground pork patties. Aerobic plate counts (APCs) of pork chops prepared from animals on control and HOSO diets did not differ (P >0·05) and no specific pattern of differences in the microflora of pork chops or ground pork patties could be attributed to diet. However, after 4 days of refrigerated storage, APCs of ground pork patties from animals fed the HOSO diet were lower (P<0·05) than those of comparable patties prepared from animals fed the control diet.     

Characteristics of pork products from Swine Fed a high monounsaturated fat diet: Part 1-Whole muscle products

Twelve percent of high-oleic sunflower oil (HOSO) was incorporated into a swine diet to replace substantial amounts of saturated fatty acids (S) in pork by monounsaturated fatty acids (M). Pork loin chops (longissimus dorsi), cooked to 74°C, and eye of round roasts (semitendinosus), cooked to 77°C, from animals on the HOSO diet were 49% and 66%, respectively, higher in the M/S ratio as compared to their counterparts from animals on the control diet. Cooking had little effect on relative differences in the M/S ratio between HOSO and control samples. Cooking loss and sensory properties were not adversely affected by the changes in fatty acid composition. However, cooked chops and roasts from the HOSO group had lower thiobarbituric acid values during storage at 4°C.     

Characteristics of pork products from swine fed a high monounsaturated fat diet: Part 3-A high-fat cured product

Fresh pork bellies from animals fed a control sorghum-soybean diet and a similar diet containing 12% high-oleic sunflower oil (HOSO) were cured and processed in a smokehouse to an internal temperature of 55·6°C. Cooking losses were not significantly different (p < 0·05) between bacon strips from animals on the control diet and those from animals on the HOSO diet. The ratio of monounsaturated fatty acids to saturated fatty acids for the cooked rasher from the HOSO group was 1·84 times that for the cooked rasher from the control group (2·48 versus 1·35). The cooked rasher had a slightly lower (p < 0·05) percentage of total monosaturates that uncooked bacon strips within each diet group. When considering stearic acid as a fatty acid that does not raise the plasma cholesterol level in the human, along with all unsaturated fatty acids, only 16·83% and 12·26% of total fatty acids in the cooked rasher and the drip, respectively, from the HOSO group were fatty acids (C14:0 and C16:0) which may raise the plasma cholesterol level. The residual nitrite level in the raw and cooked bacon was higher (P < 0·05) for samples from the HOSO group than for those from the control group, probably due to binding of nitrite to the double bonds in unsaturated fatty acids that were higher for samples from the HOSO group. The extent of the accumulation of thiobarbituric acid-reactive substances during frozen storage was not affected (P > 0·05) by the inclusion of 12% HOSO in the animal diet, regardless of the packaging method.     

Effect of dietary high-oleic sunflower oil on pork carcass traits and fatty acid profiles of raw tissues

Ten gilts were randomly assigned to either a control sorghum-soybean diet or a similar diet containing 12% high-oleic sunflower oil (HOSO). No significant differences between the two groups were found in feedlot performance, carcass muscling and marbling score, but animals fed the HOSO diet had softer carcass fat and oilier carcasses than those fed the control diet. The ratio of monounsaturated fatty acids to saturated fatty acids (M/S) for subcutaneous fat increased from 1·58 in the control group to 3·76 in the HOSO group (138% increase); the M/S ratio for muscles (longissimus dorsi, semimembranosus and semitendinosus) increased from 0·96–1·19 to 1·84–1·88 (73% increase on an average). The percentage of polyunsaturated fatty acids in both adipose or muscle tissue was generally similar between the two diet treatments.     

Fatty acid content and composition of english beef, lamb and pork at retail

We have determined the fatty acid content and composition of retail samples of meat and assessed them with respect to UK dietary recommendations. Fifty beef sirloin steaks, pork chops and lamb chops were purchased from four supermarkets on separate occasions. The percentage of muscle (boneless basis) in the samples was 84.4 ± 4.3, 69.8 ± 7.7 and 78.9 ± 7.1 for beef, lamb and pork, respectively, with fatty acid contents of 3.84 ± 1.3, 4.73 ± 1.66 and 2.26 ± 0.7 g per 100 g muscle, respectively. Adipose tissue fatty acid contents were 70.0 ± 8.2, 70.6 ± 8.6 and 65.3 ± 9.4 g per 100 g tissue. A range of C20 and C22 polyunsaturated fatty acids (PUFA) was present in the muscle of all three species and pork adipose tissue but their concentrations in lamb and beef adipose tissue were too low to measure. The mean P:S ratios for beef, lamb and pork muscle were (adipose tissue values in parentheses): 0.11 (0.05); 0.15 (0.09) and 0.58 (0.61), and the n−6:n−3 ratios were 2.1 (2.3), 1.3 (1.4) and 7.2 (7.6). We conclude that the muscles of red meat species are a valuable source of PUFA, particularly the C20 and C22 n−3 fatty acids, in the human diet and that, considered as part of a varied diet, the low P:S ratio of the ruminant muscle, the high n−6:n−3 ratio of pork and the total fatty acid contents do not detract significantly from the nutritional value of lean meat.     

Oxidative stability of frozen-stored raw pork chops, chill-stored pre-frozen raw pork chops, and frozen-stored pre-cooked sausages in relation to dietary CuSO4, rapeseed oil and vitamin E

 Danish Landrace× Danish Yorkshire female pigs were fed either a standard diet or a standard diet enriched with 6% rapeseed oil and supplemented with increasing amounts of vitamin E (0, 100 or 200 mg all-rac-α-tocopheryl acetate/kg feed) and copper (0, 35 or 175 mg CuSO₄/kg feed), and the effect of dietary regimen on the oxidative stability of (1) frozen-stored raw pork chops packed in atmospheric air, (2) chill-stored pre-frozen pork chops packed in atmospheric air, and (3) freezer-stored, vacuum-packed pre-cooked sausages was investigated. The addition of 6% rapeseed oil did not influence the oxidative stability of the pork chops negatively, whereas the oxidative stability of a product such as the pre-cooked sausages (Danish dinner sausages) with a higher fat content (15%) decreased as a result of rapeseed oil feeding. Inclusion of rapeseed oil in the diets increased the amount of monounsaturated fatty acids and polyunsaturated fatty acids (PUFAs) in the meat and fat for the production of sausages at the expense of the content of the saturated fatty acids, and the higher content of PUFAs readily explains the decreased oxidative stability of the pre-cooked sausages. Feeding pigs 100 mg or 200 mg all-rac-α-tocopheryl acetate/kg feed significantly increased the oxidative stability of the pork chops and the detrimental effect of rapeseed oil observed in the pre-cooked sausages was effectively neutralised by both levels of vitamin E supplementation. Supplementation with copper did not affect the oxidative stability of any of the products. The presented results show that it is possible to produce pork products with a nutritionally improved fatty acid profile by inclusion of 6% rapeseed oil, without affecting the oxidative stability of the products negatively, through the protection provided by dietary vitamin E. Received: 23 March 1998 / Revised version: 28 May 1998     

Low-fat Frankfurters with Elevated Levels of Water and Oleic Acid

The effects of simultaneous incorporation of maximum allowable levels of water and high-oleic sunflower oil (HOSO) on frankfurter properties were investigated. The formulation changes generally had little effect on processing yield. Frankfurters formulated with HOSO were 180-241% higher in the ratio of total monounsaturated fatty acids to total saturated fatty acids when compared to control products with similar total fat levels. Consumer-panel sensory data and instrumental texture profile data indicated that low-fat (14-16%), high-water, HOSO frankfurters- were as acceptable as control frankfurters with 28% fat (all-animal fat) and did not have the texture problems observed previously with low-fat, HOSO frankfurters without extra added water.     

Effect of cooking on the chemical composition of low-salt, low-fat Wakame/olive oil added beef patties with special reference to fatty acid content

Changes in chemical composition, with special reference to fatty acids, as affected by cooking, were studied in low-salt (0.5%)/low-fat patties (10%) with added Wakame (3%) and partial or total replacement of pork backfat with olive oil-in-water emulsion. The addition of Wakame and olive oil-in-water emulsion improved (P < 0.05) the binding properties and the cooking retention values of moisture, fat, fatty acids and ash, which were close to 100%. Partial and total replacement of animal fat with olive oil-in-water emulsion reduced (P < 0.05) saturated fatty acids (SFAs), while total replacement also reduced (P < 0.05) polyunsaturated fatty acid (PUFAs) contents. The fatty acid concentration in cooked patties was affected by product formulation. Unlike the case of all animal fat patties, when olive oil was added the cooking process increased (P < 0.05) SFAs, monounsaturated fatty acids (MUFAs) and PUFA n-3 (linolenic acid) and n-6 (linoleic acid) contents. Cooked formulated patties with seaweed and partial or total replacement of pork backfat by oil-in-water emulsion and with seaweed added were less calorie-dense and had lower SFAs levels, while samples with olive oil had higher MUFAs levels.     

ANCM bibliography

Changes in fatty acid profiles of pork loin chops fried in different culinary fats (olive oil, sunflower oil, butter and pig lard) during 10 days of refrigerated storage were studied. Olive oil-fried loin chops (OOLC) were significantly highest in monounsaturated fatty acids (MUFA) and C18:1. Sunflower oil-fried loin chops (SOLC) showed the highest polyunsaturated fatty acid (PUFA) proportions, mainly due to C18:2 contents. Butter-fried loin chops (BTLC) were significantly richer in saturated fatty acids (SFA), such as C12:0, C14:0 and C16:0, while pig lard-fried loin chops (PLLC) contained moderate proportions of SFA, MUFA and PUFA. Fatty acid profiles of neutral lipids (NL), free fatty acids (FFA) and polar lipids (PL) were slightly changed after refrigerated storage. After 10 days of refrigerated storage, differences among samples fried in different culinary fats were maintained or increased. NL from OOLC had the significantly largest percentages of C18:1 and MUFA, while SOLC had the significantly largest percentages of C18:2 and PUFA. The highest percentages of C12:0, C14:0, C16:0 and SFA were characteristic for pork loin chops fried in butter at the end of the storage period. Refrigerated pork loin chops fried in pig lard showed intermediate percentages of SFA, MUFA and PUFA. OOLC had a more desirable nutritional value than other fried pork loin chops after and before the refrigerated storage.     

INFLUENCE OF FEED FAT SOURCE ON FATTY ACID COMPOSITION, UNSATURATION AND LIPID OXIDATION OF BACKFAT AND SENSORY QUALITY OF PORK

The effect of different fats in a 9% fishmeal feed on backfat fatty acid composition, oxidation and pork sensory attributes was studied. The hydrogenated fish oil group (HFO) had significantly increased uptake of certain fatty acids in contrast to the other groups. Iodine values were highest in the fish oil group, followed by the lamb tallow group (LT) with the control group, containing no added fat, tailing. Backfat from the HFO group had more polyunsaturated fatty acids compared to the other groups and stearic/linoleic acid ratio suggested more oxidative problems with this group. The HFO group led the LT group in oxidation with the control group being most stable. Sensory traits of fresh and frozen pork chops correlated with the oxidation results. Fat from pigs fed hydrogenated fish oil in their diet are therefore more susceptible towards oxidation possibly due to more polyunsaturated fatty acids and oxidation products in the backfat.     

Effect of Salt Concentration on Quality of Restructured Pork Chops

Restructured pork chops containing approximately 15% fat were manufactured from fresh hams and boston butts taken from sows. The effects of salt level (0%, 0.5%, 1.0%, and 1.5%) and freezer storage time (0 and 30 days) on quality attributes of restructured pork chops were studied with three replications. Triangle test differences were significant for all comparisons except 1.0% and 1.5% salt groups stored for 30 days. 2-Thiobarbituric acid (TBA) values increased linearly with increasing salt levels for both 0 and 30 days storage. Salt addition also linearly increased Instron slicing strength values, and improved flavor, juiciness, and textural properties. The addition of salt decreased raw color evaluations, Instron shearing values and cooking losses. Following 30 days freezer storage, treatments containing salt had higher TBA values and lower color scores than the control treatment containing 0% salt. Salt addition at levels between 0.5 and 1.0% is recommended for restructured pork chops.     

Effects of Dietary Antioxidants and Oxidized Oil on Membranal Lipid Stability and Pork Product Quality

The effects of dietary tocopherol and oxidized oil on the oxidative stability of membranal lipids in pig muscles and on the oxidative stability of pork products during refrigerated and frozen storage were evaluated. Membrane-bound α-tocopherol stabilized the membranal lipids and reduced the extent of lipid oxidation occurring in pork patties and pork chops during storage. Oxidized dietary oil had an adverse effect on the stability of both the membranal lipids and pork products. The addition of salt to the pork patties accelerated the oxidative process when the patties were stored under fluorescent light and in the dark.     

Color and Bind Strength of Restructured Pork Chops: Effect of Calcium Carbonate and Sodium Alginate Concentration

The effects of calcium carbonate concentration (0.00-0.26%) and sodium alginate concentration (0.0-1.4%) on the amount of discoloration and the raw- and cooked bind-strength of restructured pork chops were investigated. Alginate slightly increased and calcium carbonate decreased the amount of discoloration in the restructured chops. The beneficial effect calcium carbonate had on discoloration did not appear to be due to increased pH. Restructured chops prepared with alginate were more discolored (P<0.05) than restructured chops prepared with salt and phosphate. The optimum concentration of calcium carbonate and alginate required for minimum discoloration and maximum raw-and cooked bind-strength was 0.13% and 0.7%, respectively.     

Evaluation of the antioxidant potential of grape seed and bearberry extracts in raw and cooked pork

The effect of grape seed extract (GSE) and bearberry (BB), on lipid oxidation (TBARS, mg malondialdehyde (MDA)/kg muscle), colour (CIE ‘a’ redness value), pH, microbial status (log₁₀CFU colony forming units/g pork) and sensorial properties of cooked pork patties was investigated. GSE (0–1000 μg/g muscle) and BB (0–1000 μg/g muscle) were added to raw pork (M. longissimus dorsi) patties which were stored in modified atmosphere packs (MAP) (75% O₂:25% CO₂) for up to 12 days at 4 °C. Cooked pork patties were stored in MAP (70% N₂:30% CO₂) for up to 4 days at 4 °C. Mesophilic plate counts and pork pH were unaffected by GSE and BB. GSE and BB addition decreased (P < 0.05) lipid oxidation (TBARS) in raw pork patties on days 9 and 12 of storage, relative to controls. Antioxidant activity of GSE and BB was observed in cooked pork patties demonstrating the thermal stability of GSE and BB. The ‘a’ redness values of raw and cooked pork patties marginally increased with increasing GSE concentration. The sensory properties of cooked pork patties were unaffected by GSE and BB addition. Results obtained demonstrate the potential for using health promoting nutraceuticals in meat and meat products.     

Effects of dietary soybean oil on lipid and protein oxidation in pork patties during chill storage

The effect of dietary soybean oil on lipid and protein oxidation in low and high fat pork patties made from quadriceps femoris during chill storage in a high oxygen atmosphere packaging (80% O(2)/20% CO(2)) in the dark for 7 days was investigated. Pigs were fed either a standard diet or a diet added 2% soybean oil. After slaughter high fat pork patties were prepared for both feeding regimes by addition of back fat from pigs fed the same diet whereas low fat pork patties were prepared without addition of back fat. The 2% soybean diet increased the amount of unsaturated fat in the pork. Secondary lipid oxidation products determined as thiobarbituric acid reactive substances (TBARS) were found to increase in the pork patties with increased unsaturated fat. Increased unsaturated fat in the pork patties had no effect on protein oxidation determined as free protein thiol content and protein carbonyl content. A small, but significant increase in protein oxidation was found in the high fat pork patties independent on dietary fat. In conclusion, protein oxidation is unaffected by dietary fat in pork patties during chill storage for periods normally used in retail trade, and lipid and protein oxidation are not coupled under these conditions.     

Properties of Low-Fat Frankfurters Containing Monounsaturated and Omega-3 Polyunsaturated Oils

Properties of low-fat (<18%) frankfurters containing high-oleic acid sunflower oil (HOSO) and fish oil were studied. Replacement of animal fats by the oils had little effect on emulsion stability. Frankfurters with 5% fish oil had very low sensory scores due to undesirable fish flavor. Incorporation of maximum amounts of HOSO into low-fat beef/pork and all-beef frankfurters increased oleic acid by 34% and 62%, respectively, and the monounsaturated/saturated fatty acid ratio by 178% and 468%, respectively, compared to a regular (30% fat) product containing only animal fats. Sensory evaluation and instrumental texture profile analysis showed that the reduction in total fat caused texture problems, especially increased firmness and springiness and decreased juiciness.     

Antioxidative Fat Replacer and High-Monounsaturated Oil Used for Pork Fat in Precooked Sausage

One high-fat and four low-fat pork sausage formulations were made: P30 with 30% pork fat (P); P11-W with 11% P and 10% added water (W); P11-WC with 11% P, 9.5% W and 0.5% carrageenan (C); Pso11-WC with 6% P plus 5% high-oleic sunflower oil (So), 9.5% W and 0.5% C; and Pso11-WGcf with 6% P plus 5% So, 7.0% W and 3% defatted glandless cottonseed flour (Gcf). Sausage patty cooking yield was highest for P11-WC and Pso11-WGcf. TBA values for refrigerated precooked patties were lowest for Pso11-WGcf, whereas carrageenan had a prooxidant effect in low-fat patties made with all-pork fat. The oil had no adverse effects on lipid oxidation and sensory properties of low-fat patties with C. The monounsaturated to saturated fatty acid ratio increased by 53–71% in the So-containing low-fat patties when compared to P11-W and P11-WC patties.     

Fatty acids, cholesterol and protein content of nutria (Myocastor coypus) meat from an intensive production system in Uruguay

This study describes the total lipids, protein and fatty acids in the meat, liver, brain and adipose tissue of five male and five female nutria (Myocastor coypus). The animals were reared on a specialized farm in Uruguay. Total lipid content was between 1.41% and 1.84% in males and females. Total cholesterol content was between 70.1 mg and 72.7 mg/100 g of wet tissue. The protein content was between 19.56% and 22.34% in males and females. No significant differences (P > 0.05) were detected between males and females for total lipid, cholesterol or protein. Total, saturated, monounsaturated and polyunsaturated fatty acid values were higher (P < 0.001) in female than in male thigh muscle. Pectoral muscle had more (P < 0.05) saturated and monounsaturated fatty acids in females than in males. Subcutaneous adipose tissue from females had the highest (P < 0.01) total, saturated and monounsaturated but not polyunsaturated fatty acids while abdominal adipose tissue from males had more polyunsaturated fatty.