OXIDATIVE STABILITY OF PORK PEPPERONI DURING PROCESSING AND DIFFERENT PACKING AND STORAGE CONDITIONS AS INFLUENCED BY FAT SOURCE

Pepperoni made from pigs fed diets containing fishmeal and different fat sources was studied for changes in fatty acid composition, oxidation and sensory characteristics during ripening and different storage condition. Fatty acid composition did not change during processing and ripening. Oxidation was low for all groups after processing and ripening, and vacuum and MAP packing kept oxidation low at 6C. Pepperoni from pigs fed lamb tallow (LT) and hydrogenated fish oil (HFO) had, however, developed unacceptable flavor changes at 6C. Oxidation proceeded rapidly at 23C with the HFO group leading. Lower storage quality of the HFO group pepperoni could be from more polyunsaturated fatty acids. Inclusion of HFO and LT at 5% into pig feed was determined unacceptable but 9% high quality fishmeal without any added fat sources appears acceptable. Measured oxidation values (peroxide and p-anisidine values) may not be good indicators of flavor changes of pepperoni during storage.     

INFLUENCE OF LOW FAT FISHMEAL ON FATTY ACID COMPOSITION AND SENSORY QUALITY OF PORK

Four groups of growing-finishing pigs, were fed low fat fishmeal together with an increased level of fish oil. Additional fish oil increased the content of long-chain n-3 fatty acids in subcutaneous fat and muscle when feeding up to 9 g fish oil kg^-1 diet. Sensory quality of fresh meat was not affected by the increased level of fish oil in diets but the intensity of off-flavor/odor and rancid flavor/odor of fat increased after six months of frozen storage. Partial least square regression of rancid flavor/odor after six months of frozen storage using the significant variables C20:1, C20:5 (EPA), C22:5 (DPA) and C22:6 (DHA) in subcutaneous fat gave correlation coefficients as high as 0.92. Based on these results, the use of low fat fishmeal is acceptable but the content of fish oil should be limited to 3 g fish oil kg^-1 diet for growing-finishing pigs.     

Functional Characteristics, Fatty Acid Composition, and Palatability of Bacon from Pigs Fed Canola

Thirty-six pigs were fed diets containing 20% intact canola (IC), 20% ground canola (GC) or 0% canola (C). Processing yields and proximate composition of bacon were not affected by diet. Bacon from pigs fed GC had less saturated fatty acids and more monounsaturated fatty acids than bacon from pigs fed the IC or C diets. Bacon from pigs fed the C diet had less polyunsaturated fatty acids than bacon from pigs fed the IC or GC diets. Palatability of bacon from C, IC or GC treatments after 0 or 4 weeks storage was not different. After 8 weeks of storage, panelists tended to prefer control bacon over bacon from pigs fed the GC diet. Bacon from pigs fed the GC diet had higher 2-thiobarbituric acid values than bacon from pigs fed the IC or C diets.     

Effect of sugarcane diets and a high fibre commercial diet on fresh meat and dry-cured ham quality in local Caribbean pigs

The effects sugar cane (SC) diets and a milling by product diet on meat quality characteristics of fresh meat and dry-cured ham were studied on a total of 48 Creole (CR) pigs. Pigs were fed with a control soya-bean meal corn diet (C1), a soya-bean meal wheat diet (C2), a SC fresh juice diet (SC-J), or a ground cane diet (SC-G). Average BW gain was 657, 530, 546, and 200 g/d for diets C1, C2, SC-J and SC-G, respectively. Lean cuts (i.e., ham and loin) were significantly higher in SC-G than in C1 pigs (472 vs. 424 g/kg; P < 0.01); intermediate values were found for C2 and SC-J pigs (427 and 412 g/kg, respectively). The ultimate pH in LD muscle was lower in SC-J than the other groups (5.44 vs. 5.65; P < 0.01). The intra muscular fat (IMF) content in LD was significantly higher in SC-J diet and lower in SC-G diet (1.9% and 1.0%, respectively); intermediates values were found for C1 and C2 diets (1.4% on average). Ham weight losses during 6 months drying period were lower for SC-G fed pigs (9.7% vs. 12.4%; P < 0.05) whereas weight losses during the 12 months drying period were not affected by diet. The TBA value in dry-cured ham was not affected by diet (P > 0.05) whereas the fatty acids profiles of subcutaneous fat in SC-J and SC-G pigs contained more mono-unsaturated and less polyunsaturated fatty acids than in C1 and C2 groups. Significant effects of dietary treatment were found for dry-cured ham sensory quality parameters.     

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.     

Influence of the oxidative quality of dietary oil on broiler meat storage stability

Broilers were fed a high fat diet containing 11% oil (9% rapeseed oil, 2% soya bean oil) and the oil was given either as fresh (peroxide value of 1 meqv. O₂kg⁻¹ oil) or as highly oxidised (peroxide value of 156 meqv. O₂kg⁻¹ oil). Diets were supplemented with 46 mg all-rac--tocopheryl acetate kg⁻¹ diet, resulting in a tocopherol content of 80.8 mg -tocopherol and 58.6 mg γ-tocopherol per kg diet in the fresh oil diet and of 44.0 mg -tocopherol and 18.3 mg γ-tocopherol per kg diet in the oxidised oil diet, respectively, reflecting the degradation of the natural occurring tocopherols in the oxidised diet. Only minor differences were seen with respect to fatty acid composition in muscles from birds fed the two diets. The oxidation of the dietary oil lowered lipid stability significantly (p < 0.01) in both raw and precooked meats during chill storage, whereas only minor effects on the stability of frozen meat were seen. Tocopherol levels were significantly lower (p < 0.01) in muscles from birds fed the oxidised oil diet, explaining the decreased lipid stability of meat from these birds. Thigh meat was more susceptible to lipid oxidation during storage than breast meat, regardless of dietary treatment, although thigh meat had markedly higher tocopherol levels than breast meat. The molar ratio of PUFA > 18:2 (polyunsaturated fatty acids with three or more double bonds) to -tocopherol was significantly (p < 0.01) higher in thigh meat compared with breast meat, explaining the lower stability of the former during storage.     

The effect of olive leaves supplementation on the feed digestibility, growth performances of pigs and quality of pork meat

The influence of olive leaves supplementation on feed digestibility, growth performance of pigs and pork meat quality was investigated. Pigs fed diets with olive leaves at 5% (OL5) and 10% (OL10) levels had lower daily weight gain (DG) and daily feed intake (DFI) than pigs fed a conventional diet (OL0) but differences were not observed between groups fed with the different quantities of leaves. Additionally, pigs fed diets with leaves had the worst feed:gain ratio and showed a decrease in overall backfat. Chops from pigs fed the leaf diets had lower peroxide (PV) and conjugated diene (CD) contents than chops from pigs fed conventional diets. Moreover, chops from pigs fed with the higher quantity of leaves also showed a lower drip loss. After a storage period of 8 days at 4 °C, meat obtained from both OL5 and OL10 animals also differed (P < 0.05) in PV and %CD values from those fed a conventional diet. Since the fatty acid composition of the longissimus muscles was not different, differences in oxidative stability could only be explained by the significantly higher α-tocopherol concentration in intramuscular fat and backfat in pigs fed with olive leaf diets.     

Nutritive value of meat meals. 3. Value of meat meals as supplements to a cereal basal diet: limiting amino acids in these diets

When fed to rats and pigs as supplements to a cereal-based diet, meat meals were of significantly lower quality than fishmeal. The order of amino acid limitation in the meat meal-plus-cereal diet was first lysine and equal second methionine and threonine. Supplementation of meat meal with these three amino acids gave performance approximately equal to that obtained with fishmeal. Results obtained with the two species were very similar.     

Effect of oxidized dietary lipid and vitamin E on the colour stability of pork chops

The effect of oxidized corn oil and vitamin E (α-tocopheryl acetate) in pig diets on the oxidative stability of muscle lipids and on the surface colour characteristics of fresh and previously frozen pork chops in refrigerated storage was investigated. Lipid oxidation (TBARS values) and surface redness (Hunter 'a' values) were significantly influenced (P < 0·01) by dietary α-tocopheryl acetate levels but not by degree of oxidation of dietary corn oil. Lipid oxidation and colour deterioration during refrigerated storage were greater in previously frozen chops compared to fresh chops. TBARS values were lower and Hunter 'a' values higher in pork chops from pigs fed 100 and 200 mg α-tocopheryl acetate/kg diet compared to pigs fed 10 mg/kg diet after 2, 4, 6 and 8 days of refrigerated storage. Hunter 'a' values were significantly correlated (P < 0·01) with the logarithm of TBARS values. The results suggest that oxidation of myoglobin precedes oxidation of muscle lipids in pork chops stored at 4°C.     

Features of secondary immune response and status of nonspecific resistance of the rat, fed rations with mare's milk, rich in essential fatty acids

The influence of essential fatty acids of mare's milk fat on the immunocompetent system and nonspecific resistance was investigated after 6 and 8 weeks of feeding. Rats were fed with isocaloric purified diets containing 15% of test fat (combination of lard and sunflower oil--in control) which provide the ratio of omega-6/omega-3 fatty acids equal to 0.76. After 6 weeks of feeding an increase of immune responsiveness and nonspecific resistance in the group fed with the diet with mare's milk fat on the 6th day a single immunization of the animals with 5% sheep erythrocyte suspension was noted but that increase of secondary immune responsiveness was not noted after 8 weeks of feeding, an increase of nonspecific resistance is kept.     

Effect of redfish meal enriched diets on the taste and n-3 pufa of 42-day-old broiler chickens

Broiler chickens were fed diets supplemented with redfish meal at levels of 4,8 and 12 %. A control group was fed with an all-vegetable protein diet. After 42 days the birds were slaughtered and edible tissues (white, dark and skin) were analysed for lipid content and composition. The white and dark meats were tasted organoleptically for the possible presence of ‘fishy’ off-flavours. There was no change in the content or class composition of the lipids with diet or sex of the bird, but in meats an increase in fish meal in the diet caused an increase in the level of n-3 polyunsaturated fatty acids present, especially 20: 5n-3 eicosapentaenoic acid, 22: 5n-3 docosapentaenoic acid and 22: 6n-3 docosahexaenoic acid at the expense of n-6 fatty acids. The enrichment was most pronounced in white meat of both male and female birds and could make a contribution of n-3 polyunsaturated fatty acids to the human diet quantitatively similar to that of an equal portion of lean white fish. Taste panel results showed that there was no significant difference in flavour or taste among any of the samples. There was a tendency for the 12% dietary group birds to be the least preferred, but no panelist detected ‘fishy’ flavours or objected to the taste of the meat.     

Feeding supplemental fat and undegraded intake protein to early lactation dairy cows.

Forty-eight Holstein cows (16 primiparous) were fed alfalfa silage-based TMR containing 18% CP with 33 or 36% of the CP as undegraded intake protein and with 0 or 2.8% supplemental fat (DM basis). Expeller soybean meal replaced solvent soybean meal to vary undegraded intake protein, and sodium alginate-treated tallow was used as the fat source. A standard diet containing solvent soybean meal without fat was fed during the first 21 d postpartum for covariate adjustment of milk production. A continuous lactation design with 2 x 2 factorial arrangement of treatments was used with supplemental fat and undegraded intake protein as main effects. Feeding supplemental fat increased actual milk (32.9 vs. 31.7 kg/d) but decreased milk protein concentration. Cows fed supplemental fat also had higher BW, and weight gain was significant with time. Increasing undegraded intake protein did not affect milk yield, composition, or component yield. There were no significant interactions between supplemental fat and undegraded intake protein on milk yield or composition. Milk fatty acid composition was not altered by addition of undegraded intake protein, but C6 to C14 fatty acids were reduced by adding supplemental fat. Results do not support the strategy of increasing levels of undegraded intake protein when supplemental fat is fed. Variation in undegraded intake protein content of feed-stuffs appears to be of more importance in ration formulation than interactions between supplemental fat and protein.     

High Dietary Vitamin E Affects Storage Stability of Frozen-refrigerated Trout Fillets

Fillets were processed from trout fed a diet containing either 200 (low vitamin E [LVE] diet) or 5000 (high vitamin E [HVE] diet) mg a‐tocopheryl acetate/kg for 0, 4, and 9 wk. These fillets were evaluated fresh and after 6 mo of frozen storage. Frozen fillets were thawed and stored 3 d at 1 °C before analyses. Muscle α‐tocopherol of fish fed the HVE diet continuously increased through 9 wk of feeding. Reduced muscle α‐tocopherol and moisture, and increased muscle redness and fat were observed in frozen‐refrigerated fillets compared with fresh fillets. Thiobarbituric acid‐reactive substances were lower in frozen‐refrigerated fillets produced from fish fed the HVE diet. Proportion of unsaturated fatty acids and omega‐3 fatty acids increased as feeding duration increased from 0 to 9 wk.     

Effects of feeding elevated concentrations of monounsaturated fatty acids and vitamin E to swine on characteristics of dry cured hams

Thirty Large White×Great York gilts were fed six experimental diets containing three levels of poly and monounsaturated fatty acids. Within each dietary fat treatment, one group was fed a basal level of vitamin E (20 mg α-tocopheryl acetate/kg diet) and the other group received a supplemented level (200 mg α-tocopheryl acetate/kg diet). Concentration of α-tocopherol was significantly higher in hams from pigs fed supplemented dietary levels of vitamin E (P<0.0001), but no significant effect of dietary fat was observed. Dietary vitamin E supplementation reduced the concentration of thiobarbituric acid reactive substances after 9 days storage of sliced samples (P<0.0001), while dietary fat source showed no significant effect. Significantly lower oxidation was observed in ham homogenates from pigs fed higher concentrations of monounsaturated fatty acids after 120 min of incubation under pro-oxidant conditions (P=0.013). No effect of dietary treatment was observed in ham volatile aldehyde profile. No significant effect of dietary vitamin E was observed on surface redness during storage, but a significant effect was observed for luminosity after 7 days of storage (P=0.033). Hams from pigs fed diets enriched in monounsaturated fatty acid showed higher ‘a’ values (P=0.040) in stored sliced samples. Sensory evaluation revealed a significant effect of dietary vitamin E on redness of ham slices (P<0.001). Dietary supplementation with vitamin E also produced a significantly higher odour and flavour intensity (P=0.006 and P=0.01 respectively). Dry cured ham samples from pigs fed higher amounts of monounsaturated fatty acids showed a significantly higher consistency fat than those from pigs fed polyunsaturated fatty acids.     

Incorporation of dietary polyunsaturated fatty acids in pork tissues and its implications for the quality of the end products

One hundred and ten fattening pigs of a Piétrain × Hybrid cross-barrows and gilts in equal numbers-were distributed over five feeding formulas, containing increasing amounts of polyunsaturated fatty acids (PUFA), in the form of rapeseed. The aim of the study was to evaluate the maximum admissible amount of PUFA in the pig diet before problems-in terms of backfat consistency and storage stability-occur and to investigate the incorporation of dietary PUFA in intramuscular fat as well. A tendency towards reduced feed (energy) intake was obvious from the 7% rapeseed inclusion level, apparently resulting in a somewhat thinner backfat layer. None of the backfat samples showed a visible yellow discolouration instead thin backfat layers appeared as pink. Backfat consistency was lower for gilts and decreased with increasing dietary PUFA levels. PUFAs in the feed and in backfat were very well correlated (0.8-0.9) as expected; correction for de novo fat synthesis (by means of backfat thickness) did not alter the correlations within one sex group. Thresholds for PUFA in feed-15 g PUFA/kg feed-and for PUFA in back-fat-iodine value of 70 or 15% PUFA-were all surpassed in this experiment: 18 g PUFA/ kg feed resulted in maximally 22% PUFA in the outer backfat layer. The backfat PUFA limit was reached at relatively low feed PUFA levels. This might be explained by thin and hence more unsaturated backfat layers in lean or underweight pigs. Oxidative stability of the backfat after storage for 1 year in the freezer was satisfactory. The total intramuscular fat (IMF) content showed no obvious relationship with diet, in contrast with sex: barrows had more IMF than gilts. IMF consisted in 80% apolar phase and 20% polar fraction. The apolar fraction showed similar feed and sex tendencies as backfat, although correlations between feed and apolar fraction PUFAs were higher for gilts than for barrows. The amount of phospholipid was invariable throughout all treatments. Only linoleic acid-the major fatty acid-showed some feed and sex influence. In view ofthf results obtained the threshold for feed and backfat PUFA can be as high as, respectively, 18 g PUFA/kg feed and 22% PUFA in backfat, without deterioration of fresh and frozen backfat. However, for meat processing, demands could be more severe.     

Effects of RN genotype and silage feed on fat content and fatty acid composition of fresh and cooked pork loin

This study aimed to establish effects of RN genotype and feed (red clover silage) on intra muscular fat content (IMF) and fatty acid composition (FA) of fresh and cooked pork loin (M. longissimus dorsi). Raw loins from silage-fed pigs compared with those from conventionally fed pigs had lower IMF, lower relative levels (rel.%) of saturated (SAFA) and monounsaturated (MUFA) fatty acids, and higher rel.% of polyunsaturated fatty acids (PUFA, ω6, ω3). Cooked loins, from silage-fed pigs compared with those of conventionally fed pigs, had higher rel.% of ω3, and lower ω6/ω3 ratios. IMF and cooking influenced FA concentrations in a pork portion. The differences in concentrations of SAFA, MUFA, PUFA and ω6 between raw loins of silage-fed pigs and conventionally fed pigs did not remain in cooked loins. The ω6/ω3 ratio, however, remained low, and thus more beneficial in loins from silage-fed pigs after cooking.     

Milk production and composition from cows fed wet corn distillers grains

Twelve lactating Holstein cows were utilized in a repeated switchback design to evaluate milk production and milk fat composition responses to wet corn distillers grains. Total mixed diets consisted of 31.4% corn silage, 18.4% alfalfa hay, and either 50.2% of a concentrate mix that contained mostly corn and soybean meal or 19.4% of a concentrate mix that contained mostly corn and 31.2% wet corn distillers grains. The first 4 wk of each 6-wk period were for adaptation to diets; data were collected during wk 5 and 6 of each period. Although dry matter intake (22.1 vs. 19.7 kg/d) was lower when cows were fed the wet corn distillers grains diet, milk production (30.7 vs. 30.8 kg/d) was similar for cows fed both diets. Milk fat (3.60 vs. 3.85%) was slightly higher, and protein (3.06 vs. 2.84%) was lower, when cows were fed the wet corn distillers grains diet. Milk fat from cows fed wet corn distillers grains contained lower concentrations of saturated fatty acids and higher concentrations of long-chain and unsaturated fatty acids. The feeding of wet corn distillers grains increased the proportion of unsaturated fatty acids in milk fat without changing milk production.     

Effects of fish meal protein supplementation on milk yield and composition and blood constituents of dairy cows

Ten holstein and 10 Ayrshire cows were fed diets containing undegradable intake protein from either fish meal or corn gluten meal. Cows were introduced to diets 10 d before projected calving date and individually fed blended rations until 60 d postpartum. Diets were balanced for NE1, CP, and degradable and undegradable protein. Source of undegradable protein did not affect total or FCM yields, DM intake, or milk protein percentage. Cows on fish meal diets tended to lose less BW than those on the corn gluten meal supplement (5.3 vs. 10.3% loss of initial BW). Fish meal supplementation resulted in decreased milk fat and SNF percentage (3.2 vs. 4.2% and 8.37 vs. 8.65%, respectively), but diet did not affect total milk fat, protein, or SNF yield. Plasma nonesterified fatty acids decreased and serum insulin increased with increasing weeks postpartum but were not affected by diet. In this study, no significant advantage was found to using fish meal as a source of undegradable intake protein and feed cost was higher when it was used.     

The effect of the essential fatty acids in mare's milk on the function of the immune system and of nonspecific resistance in rats]

The influence of essential fatty acids of mare's milk fat on the immunocompetent system and nonspecific resistance of male rats weighing 135-145 g was investigated after 6 weeks of feeding. Rats were fed with isocaloric purified diets containing 15% of test fat (in control--combination of lard and sunflower oil) which provide the ratio of omega-6/omega-3 fatty acids equal to 0.76. An increase of immune responsiveness and nonspecific resistance in the group fed with the diet with mare's milk fat on day 6 after a single immunization of the animals with 5% sheep erythrocyte suspension was noted.     

Characteristics of Milk and Butter from Cows Fed Sunflower Seeds

Composition of milk and butter was evaluated from cows fed either control or experimental diets containing added fat of partially unsaturated fatty acid composition. The control diet concentrate mix consisted mainly of corn and soybean meal. The two experimental diets substituted either 20% high oleic sunflower seeds (>79% of fatty acids as oleic acid) or 20% regular sunflower seeds (>67% of fatty acids as linoleic acid) for part of the corn and soybean meal in the concentrate mix. Feeding lactating dairy cattle sunflower seeds resulted in lower concentrations of short and medium chain and higher concentrations of long-chain fatty acids in milk fat and butter. Milk unsaturated fatty acid concentrations were (28.9, 38.8, 45.6%), and butter unsaturated fatty acid concentrations were (29.6, 38.1, 44.3%) for control, high oleic sunflower seed, and regular sunflower seed treatment milk, respectively. Organoleptic evaluation indicated the high oleic sunflower seed and regular sunflower seed treatment butters were equal or superior in flavor to the control butter. The high oleic sunflower seed and regular sunflower seed treatment butters were softer, more unsaturated, and exhibited acceptable flavor, manufacturing, and storage characteristics.