Meat texture and antioxidant status are improved when carnosic acid is included in the diet of fattening lambs

Thirty-two Merino lambs fed barley straw and a concentrate alone (CONTROL group) or enriched with carnosic acid [0.6 g kg(-1) dry matter (DM), CARN006 group; 1.2 g kg(-1) DM, CARN012 group] or vitamin E (0.6 g kg(-1) DM, VITE006 group) were used to assess the effect of these antioxidant compounds on meat quality. After being fed the experimental diets for at least 5 weeks, the animals were slaughtered with the 25 kg intended body weight and the different muscles (longissimus lumborum; LL, gluteus medius; GM) were sliced and kept refrigerated under modified atmosphere packaging during 0, 7 and 14 days. The results indicate that carnosic acid seemed to be useful to delay lipid peroxidation in a medium colour-stable muscle such as GM, but this effect was lower than that observed when vitamin E was supplemented to fattening lambs. On the contrary, meat texture and protection against cholesterol oxidation were equally improved with both compounds.     

Effect of dietary carnosic acid on the fatty acid profile and flavour stability of meat from fattening lambs

Thirty-two lambs were fed with barley straw supplemented by a concentrate alone, or a concentrate enriched with either vitamin E (VITE006: 0.6 g kg⁻¹ feed concentrate) or carnosic acid (CARN006: 0.6 g kg⁻¹ feed concentrate; or CARN012: 1.2 g kg⁻¹ feed concentrate). In order to elucidate the influence of the dietary supplementation of carnosic compared with a reference diet antioxidant (vitamin E), the animals were slaughtered and the longissimus thoracis were lyophilised to determine the FAs profile and the phenolic compounds. In addition, longissimus lumborum slices were stored in a modified atmosphere package for 3 days and then grilled to determine volatile compounds. Dietary carnosic acid did not modify the FAs profile, but had a clear effect on the production of volatile compounds, in a dose-dependent manner. These results have implications for the food industry, since dietary carnosic acid seems to extend the shelf life of lamb meat.     

Carcass and meat quality characteristics and fatty acid composition of tissues from Pietrain-crossed barrows and gilts fed an elevated monounsaturated fat diet

Fifty-one (Landrace∗Large White)∗Pietrain barrows and gilts were used to compare the effect of a diet rich in oleic acid (HO) by feeding a by-product of the olive industry (Greedy-Grass OLIVA®: 1.4% growing, 3.8% finishing) or a grain and soy diet (CONTROL) on carcass characteristics, meat quality and fatty acid profile of intramuscular and subcutaneous fat. Gilts had leaner (P < 0.05) carcasses with lower fat percentage in major primal cuts, and less (P < 0.05) saturated fat compared with barrows with no interaction (P > 0.05) between dietary treatment and gender. Source of dietary fat had no effect (P > 0.05) on primal cut yields, composition of major primal cuts, or carcass and meat quality characteristics. Intramuscular fat from HO fed pigs had higher (P < 0.05) percentage of saturated (SFA) and monounsaturated (MUFA) fatty acids, and lower (P < 0.05) polyunsaturated fatty acids (PUFA) and n-6:n-3 ratio compared with CONTROL animals (37.4% vs. 36.8%, 44.7% vs. 40.1%, 17.9% vs. 23.2%, and 18.9 vs. 21.8 ratio, respectively). Subcutaneous fat from pigs fed HO had greater (P < 0.05) MUFA percentage, lower (P < 0.05) SFA and PUFA percentage, and lower (P < 0.05) n-6:n-3 ratio than pigs fed CONTROL diet (51.4% vs. 48.0%, 30.5% vs. 32.9%, 18.1% vs. 20.1%, and 9.83 vs. 11.3 ratio, respectively). Intramuscular fat had higher proportion of SFA and lower of MUFA showing a higher degree of tissue saturation compared with subcutaneous fat. Feeding Greedy-Grass increased MUFA and decreased PUFA proportions in fat depots reducing the risk of production of carcasses that are soft and oily which result in lower technological and processing quality.     

Effect of exposure to light on physico-chemical quality attributes of sliced dry-cured Iberian ham under different packaging systems

Dry-cured Iberian ham slices were stored under vacuum and under two different atmospheres (N₂ = 70% N₂ + 30% CO₂; Ar = 70% Ar + 30% CO₂) and exposed to lightness or darkness. Physico-chemical, sensory and microbial analysis was carried out throughout 60 days storage. Vacuum samples showed the highest a*-value compared to N₂ and Ar after 30 (P < 0.05) and 60 days (P < 0.05). The influence of illumination during storage was evident after 60 days of storage, L* and a*-values being lower (P < 0.01) in hams exposed to light than those kept in darkness, which can be ascribed to the lower nitrosylmioglobin content in samples exposed to light after 60 days (P = 0.001). Ham slices stored in darkness showed the lowest TBARS values (P < 0.05) and hexanal content (P < 0.05) after 60 days. Slices of ham packed in vacuum showed lower TBARS values than N₂ and Ar batches (P = 0.001), these samples being perceived as more rancid (P < 0.05). The rest of the sensory attributes were not generally affected by gas mixture or illumination (P > 0.05).     

Quercetin dietary supplementation of fattening lambs at 0.2% rate reduces discolouration and microbial growth in meat during refrigerated storage

Thirty-two Merino lambs fed barley straw and a concentrate formulated either with palm oil (CTRL group) plus quercetin (QCT group) or flaxseed (FS group) plus quercetin (FS-QCT group) were used to assess the effects of this flavonoid on meat quality attributes. The animals were slaughtered after being fed for at least 5 weeks with the experimental diets. Chemical composition of longissimus thoracis (LT) muscle was not different among treatments. The longissimus lumborum (LL) samples of QCT and FS-QCT groups revealed lower discolouration (hue angle) when compared to the CTRL and FS lambs (P < 0.05), whereas extract release volume (ERV) and microbiological data jointly suggest that flaxseed and quercetin may reduce the growth of microbial populations responsible for meat spoilage in quadriceps femoris (QF).     

Increasing omega-3 levels through dietary co-extruded flaxseed supplementation negatively affects pork palatability

To clarify the impact of feeding co-extruded flaxseed on carcass quality and pork palatability, 96 pigs (48 barrows and 48 gilts) were fed three different levels of flaxseed (0%, 5% and 10% of dietary intake) for 76 days. Carcass quality and meat quality characteristics of pure loin muscle and ground pork (20% fat) were evaluated. Fat hardness and belly firmness decreased (P < 0.001) with increasing co-extruded flaxseed. Pigs fed co-extruded flaxseed levels had higher lean yield (P = 0.045) and total lean content (P = 0.034). Loin from barrows had higher fat content compared to gilts (P < 0.001). Co-extruded flaxseed supplementation increased (P < 0.001) omega-3 content in loin and ground pork. Pork flavour intensity and off-flavour intensity scores lowered (P < 0.001) with increasing levels of co-extruded flaxseed, being more accentuated (P = 0.023) in reheated pork chops from barrows. Diet affected all texture and flavour sensory characteristics (P < 0.05) as tissue levels of omega-3 fatty acids increased, likely as a result of increased lipid oxidation.     

Influence of genetic type and level of concentrate in the finishing diet on carcass and meat quality traits in beef heifers

Carcass and meat quality traits of thirty-six feedlot beef heifers from different genetic groups (GG) fed at two concentrate levels (CL) were evaluated using 12 - Nellore (NE), 12 - ½Angus x ½Nellore (AN) and 12 - ½Simmental x ½Nellore (SN) animals. Six heifers of each GG were randomly assigned into one of two treatments: concentrate at 0.8% or 1.2% of body weight (BW). Heifers fed concentrate at 0.8% of BW had greater (P < 0.05) dressing percentage. None of the proximate analysis components of the beef were affected (P > 0.05) by either CL or GG. Heifers from the AN group had higher (P < 0.05) carcass weights, 12th rib fat thickness and lower dressing percentage (P < 0.05) compared to the other groups. NE heifers had greater WBSF values (P < 0.05) than the other genetic groups. Data suggest that the concentrate level can be reduced without compromising meat quality traits.     

Quality of fresh and seasoned fat of Cinta Senese pigs as affected by fattening with chestnut

This trial was aimed to verify the effect of fattening with chestnut on carcass characteristics and on quality traits of products of Cinta Senese breed. Thirty-three Cinta Senese pigs were allotted into three groups. One group was fed a commercial feedstuff (0-CH), the other two groups were fed chestnut for one (1-CH) or three (3-CH) months. Pigs were slaughtered at 130 kg of live weight. The 1-CH group showed significantly lower pH value at 24 h (P < 0.05). For sample joint dissection a significant effect (P < 0.05) of feeding system was found only on intermuscular fat, highest in 1-CH. A significant effect of feeding system (P < 0.05) was found on physical and chemical parameters of Longissimus lumborum: the 3-CH group showed the highest values (P < 0.05) of L*, a*, b*, drip loss, cooking loss, shear force and intramuscular fat on raw meat. The 3-CH showed significantly higher level (P < 0.05) of unsaturation for the highest percentage of MUFA and PUFA.     

Muscle changes in hard and soft shell crabs during frozen storage

Chemical and physicochemical changes of muscles from hard and soft shell mud crabs (Scylla serrata) were monitored during 12 weeks of storage at −20 °C. Ca²⁺-ATPase activity of natural actomyosin (NAM) from both crabs decreased continuously during storage, regardless of muscle types. After 8 weeks of storage, Ca²⁺-ATPase activity of NAM from lump muscle of soft shell crab decreased to a greater extent than that of hard shell crab (P < 0.05). An increase in disulfide bonds was observed with the coincidental decrease in sulfhydryl group content during extended storage (P < 0.05). Surface hydrophobicity of all samples increased up to 8 weeks, being this sampling time followed by a gradual decrease. Formaldehyde content of all samples increased throughout the storage (P < 0.05). Slightly higher formaldehyde content was found in soft shell crab muscle, compared with hard shell counterpart (P < 0.05). Claw muscle generally contained a greater amount of formaldehyde than lump counterpart (P < 0.05). Protein solubility of all samples decreased continuously throughout the 12 weeks of frozen storage (P < 0.05). Lipid oxidation took place during the extended storage as evidenced by the increase in thiobarbituric acid reactive substances. The pH of all samples generally decreased during frozen storage. Cooking loss of all crab muscles increased as storage time increased (P < 0.05) and was more pronounced in claw muscle, particularly from soft shell crab.     

Relationship between the solubility,dosage and antioxidant capacity of carnosic acid in raw and cooked ground buffalo meat patties and chicken patties

Antioxidant capacity of oil soluble and water dispersible carnosic acid (CA) extracted from dried rosemary leaves using HPLC was evaluated at two different dosages (22.5 ppm vs 130 ppm) in raw and cooked ground buffalo meat patties and chicken patties. Irrespective of total phenolic content, CA extracts reduced (p < 0.05) the thiobarbituric acid reactive substances (TBARS) by 39%–47% and 37%–40% in cooked buffalo meat and chicken patties at lower dosage (22.5 ppm) relative to control samples. However, at higher dosage (130 ppm) the TBARS values were reduced (p < 0.05) by 86%–96% and 78%–87% in cooked buffalo meat and chicken patties compared to controls. The CA extracts were also effective in inhibiting (p < 0.05) peroxide value and free fatty acids in cooked buffalo meat and chicken patties. The CA extracts when used at higher dosage, were also effective in stabilizing raw buffalo meat color.     

Behavior of Salmonella during fermentation,drying and storage of cocoa beans

Due to cocoa being considered a possible source of Salmonella contamination in chocolate, the behavior of Salmonella during some cocoa pre-processing stages (fermentation, drying and storage) was investigated. The fermentation process was carried out on a pilot scale (2 kg beans/box) for 7 days. Every day a fermentation box was inoculated with a Salmonella pool (ca. 4 log MPN/g). The results showed that Salmonella did not affect (P > 0.05) the growth of the main microorganism groups involved in cocoa fermentation. On the other hand, the pathogen was influenced (P < 0.05) by yeast, acetic acid bacteria and pH. In spite of Salmonella showing counts ≤ 1 log MPN/g in the first days, at the end of fermentation it grew in all samples, reaching counts as high as 7.49 log MPN/g. For drying and storage, cocoa beans were inoculated during the fermentation (experiment A) or during the drying (experiment B). In these stages the decline of the water activity affected the pathogen behavior. In experiment A during the drying, Salmonella count increased in most of the samples. In experiment B either a slight growth or no growth in the samples inoculated up to 48 h was observed, whereas the other samples showed reductions from the initial count. After 30 days of storage at room temperature, the water activity decreased to 0.68, and reductions of Salmonella ranged from 0.93 to 2.52 log MPN/g. Despite the reductions observed during the storage, the pathogen was detected even after 120 days. Therefore, the results showed that Salmonella growth or survival depends on when the contamination occurs.     

Effect of tannic acid and kiam wood extract on lipid oxidation and textural properties of fish emulsion sausages during refrigerated storage

Effect of tannic acid (0.02% and 0.04%) and ethanolic kiam wood extract (EKWE) (0.04% and 0.08%) on lipid oxidation and textural properties of fish emulsion sausages during 20 days of refrigerated storage was investigated. Control samples (C) had the highest peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) value up to day 16 and 8 of storage, respectively. With the addition of tannic acid and EKWE, PV and TBARS values in the sausages were retarded effectively, compared to the control (P < 0.05), especially when the tannic acid and EKWE at higher level were used. At the same level, EKWE showed the lower ability in retarding the lipid oxidation, in comparison with tannic acid. Tannic acid at both levels (0.02% and 0.04%) was also effective in retarding the formation of fishy odour in the samples throughout the storage, compared to the control and EKWE treated samples (P < 0.05). Both tannic acid and EKWE had no detrimental effect on the sensory attributes of sausages. However, EKWE treated sample had lower L^∗ and higher a^∗ and ΔE^∗ values, compared to the control samples (P < 0.05). After 20 days of storage, the sample added with 0.04% tannic acid had higher hardness, gumminess and chewiness, compared with others (P < 0.05). Samples added with 0.04% tannic acid also displayed more compact structure with no visible voids. Furthermore, oil droplets with smaller size were dispersed more uniformly, compared to others. Thus, tannic acid (0.02% and 0.04%) and EKWE (0.08%) were effective in retarding lipid oxidation and fishy odour development as well as could maintain the textural properties of fish emulsion sausages during the refrigerated storage of 20 days.     

The influence of Bifidobacterium Bb-12 and lactic acid incorporation on the properties of Minas Frescal cheese

The effects of a probiotic bacterium (Bifidobacterium Bb-12) and lactic acid on the microbiological, physicochemical, rheological and microstructural proprieties of Minas Frescal cheese were evaluated after 1 day and after 28 days of storage (5 ± 1 °C). The cheese was produced with four different treatments: with no lactic acid (C1 and C2), with lactic acid (C3 and C4) and with bifidobacteria (C2 and C3). The cheese formulations containing bifidobacteria were classified as probiotic. The addition of bifidobacteria to the cheese did not influence its yield, protein or lipid levels one day after production. Moreover, after 28 days of storage, the cheese samples with no lactic acid showed lower moisture levels compared to the samples containing lactic acid (P < 0.05). The absence of lactic acid had an influence on the rheological and microstructural behavior, making them more elastic, firm and compact, however all the cheese samples evaluated showed a higher tendency to viscosity than to elasticity. The Minas Frescal cheese with Bifidobacterium Bb-12 and lactic acid showed great potential as a functional food, with possible industrial and commercial application.     

Effects of grape seed extract on the oxidative and microbial stability of restructured mutton slices

The antioxidant and antimicrobial efficacy of grape seed extract (GSE) was studied in restructured mutton slices (RMS) under aerobic and vacuum packaging conditions during refrigerated storage. The RMS treated with grape seed extract (GSE) had significantly (P < 0.05) lower thiobarbituric acid reactive substance (TBARS) values and free fatty acids (FFA) % compared to control (C) and butylated hydroxy anisole (BHA) treated RMS during storage at 4 ± 1 °C. Addition of GSE significantly (P < 0.05) reduced the total psychrophilic and coliform counts in RMS during refrigerated storage. The GSE treated mutton slices recorded significantly (P < 0.05) superior scores of color, flavor, juiciness and overall palatability than C and BHA treated RMS. The TBARS values, FFA % and microbial counts increased significantly (P < 0.05) during storage. It can be concluded that GSE has excellent antioxidant and antimicrobial properties compared to control and BHA treated RMS during refrigerated storage under aerobic and vacuum conditions.     

Intramuscular fatty acid composition of “Galician Mountain” foals breed: Effect of sex,slaughtered age and livestock production system

The effects of sex, slaughtered age (9 vs. 12 months) and livestock production system (freedom extensive system vs. semi extensive system) of “Galician Mountain” foals breed on the fatty acid composition were studied. The sex and slaughtered age of the animals had no statistical significance in the intramuscular fatty acids. Furthermore, the livestock production system showed differences in the fatty acid profiles from the Longissimus dorsi. The feeding system showed significant differences in PUFA content (P < 0.001) higher in freedom extensive production system that semi extensive system, whereas MUFA content was significantly (P < 0.001) higher in semi extensive system. This major PUFA content in freedom extensive production showed a significant (r = 0.70, P < 0.01) correlation with C18:3n− 3 content and can be attributed to their eaten only pasture until slaughtered. The higher MUFA contents (P < 0.001) observed for semi extensive production system foals were very significant (r = 0.98, p < 0.01) correlated with C18:1cis−9 content and less significant (r = 0.81, P < 0.01) correlated with C16:1cis−9 content. In addition, the data reinforced the evidence that foals from extensive production system on wood pasture have a higher nutritional quality (mainly due to the higher levels of n−3 PUFA) when compared to concentrate-fed foals, as a result of the beneficial effects of grass on meat fatty acid profiles.     

Retardation of haemoglobin-mediated lipid oxidation of Asian sea bass muscle by tannic acid during iced storage

Lipid oxidation mediated by haemoglobin from tilapia was monitored in washed Asian sea bass mince with and without added tannic acid (200 and 400 ppm) during 10 days of iced storage. Control samples (without tannic acid) had the highest peroxide value (PV) within the first 2 days and possessed the greater amount of thiobarbituric acid-reactive substances (TBARS) throughout the storage of 10 days (p < 0.05). With addition of tannic acid, the lipid oxidation of washed Asian sea bass mince was retarded, especially when the higher level (400 ppm) was used, as evidenced by lowered PV and TBARS. The retarded formation of volatile lipid oxidation products in the samples with added 400 ppm tannic acid was found. Sensory analysis revealed that samples with added 400 ppm tannic acid possessed lower fishy odour score, compared with the control sample and that with added 200 ppm tannic acid (p < 0.05).     

Effect of dietary olive leaves and/or α-tocopheryl acetate supplementation on microbial growth and lipid oxidation of turkey breast fillets during refrigerated storage

Thirty turkeys were allocated to five groups of six birds each. One group that served as control was fed a basal diet, while the others were fed diets supplemented with olive leaves at 5 or 10 g/kg, or α-tocopheryl acetate at 150 or 300 mg/kg. Following slaughter, fillets from breast were stored at 4 °C in the dark for 12 days, and lipid oxidation and microbial growth were assessed. Results showed that the incorporation of olive leaves in turkey diets increased (P < 0.05) the oxidative stability of raw breast fillets during refrigerated storage. Dietary olive leaves at 10 g/kg were more effective (P < 0.05) in inhibiting lipid oxidation compared to 5 g/kg, but inferior to the supplementation of 300 mg α-tocopheryl acetate/kg. In turn, α-tocopheryl acetate supplementation at 150 mg/kg was equal to olive leaves at 5 g/kg but inferior to olive leaves at 10 g/kg. Total viable counts, lactic acid bacteria, Enterobacteriaceae and psychrotrophic bacteria counts were all increased (P < 0.05) in breast fillets of all groups throughout the refrigerated storage. Diet supplementation with α-tocopheryl acetate had no effect on the bacterial counts recorded in the control group, but diet supplementation with olive leaves resulted in decrease (P < 0.05) of all bacterial counts at day 2 of storage and thereafter; during this period, olive leaves at the level of 10 g/kg were more effective in inhibiting bacterial growth compared to the level of 5 g/kg.     

Enhancing pork loin quality attributes through genotype,chilling method and ageing time

The experiment was conducted to examine opportunities for enhancing pork quality through the use of post-mortem ageing when combined with different chilling regimes. Large White (LW, n = 24) and Duroc × Large White (Duroc, n = 24) barrows were slaughtered and alternate carcass sides were either conventionally or blast-chilled. The longissimus thoracis et lumborum muscle was dissected from the carcass sides (24 h post-mortem) and trimmed of cover fat. Three sections (15 cm length) were vacuum packaged and assigned to 2, 7 or 14 days of ageing (2 °C) randomized within muscle location. Blast-chilled meat had lower purge (P = 0.009) and drip (P = 0.0009) losses and higher hue (P = 0.02) than conventionally chilled meat. However chilling by conventional or blast-chilling methods had no effect on sensory characteristics (P > 0.1). When breeds were compared, meat from Duroc barrows had lower moisture (P < 0.0001) and higher intramuscular fat content (P < 0.0001), L∗ (P = 0.0003) and hue (P = 0.007) values than LW. Overall tenderness (P = 0.005), juiciness (P = 0.0007) and palatability (P < 0.0001), as well as flavour intensity (P < 0.0001) and desirability (P < 0.0001) values were higher and undesirable flavours were lower (P < 0.0001) for meat from Duroc pigs, when compared with LW. Ageing increased purge loss (P < 0.0001), L∗ (P < 0.0001), hue (P < 0.0001), chroma (P < 0.0001) and content of protein (P = 0.002), with corresponding decreases (P < 0.0001) in drip loss and moisture content. Instrumental (P < 0.0001) and sensory (initial, P < 0.0001 and overall, P < 0.0001) tenderness increased from day 2 to 14. Therefore independent of chilling method, ageing improved quality of pork loins. Moreover ageing had greater effect on tenderness, while breed had greater effect on flavour which may be related to differences in intramuscular fat content.     

Antioxidant action of ganghwayakssuk (Artemisia princeps Pamp.) in combination with ascorbic acid to increase the shelf life in raw and deep fried chicken nuggets

Raw and deep fried chicken nuggets containing various levels of ganghwayakssuk ethanolic extract (GE) in combination with ascorbic acid (Aa) were evaluated for shelf-life during refrigerated storage (4 °C). The pH and color (lightness, redness, and yellowness) values of raw and deep fried samples were significantly affected by the addition of GE (P < 0.05). All antioxidant combinations except for Aa + GE 0.01 were effective at delaying lipid oxidation (CD, POV, and TBARS) when compared to the control or Aa. Raw samples with GE 0.2 and Aa + GE 0.1 exhibited lower bacterial populations during storage. The sensory characteristics (color, juiciness, flavor, tenderness, and overall acceptability) did not differ significantly in all deep fried chicken nugget samples, except color, whereas storage time had a significant effect (P < 0.05). The results suggest the possibility of utilizing raw and deep fried chicken nuggets with a mixture of ganghwayakssuk and ascorbic acid for the increase of shelf-life and quality.     

Sulfuryl fluoride fumigation effects on the safety,volatile composition,and sensory quality of dry cured ham

A randomized complete block design with three replications was utilized to evaluate the effects (P < 0.05) of various fumigation concentrations of sulfuryl fluoride (SF) (0, 12, 24, 36 and 72 mg/L) on the fluoride, sulfuryl fluoride, and volatile flavor compound concentrations in dry cured ham. Fluoride and SF concentrations increased (P < 0.05) in dry cured hams as SF fumigation concentration increased, but all samples contained fluoride and SF concentrations below the legal limits of 20 and 0.01 ppm, respectively. Minimal differences existed (P > 0.05) in the presence and concentration of aroma active compounds, but oxidation compounds were slightly more prevalent (P < 0.05) in the 72 mg/ml treatment when compared to the control. A triangle test (n = 54) indicated that consumers could not discern (P > 0.75) between hams that were fumigated with SF at 0 and 36 mg/ml. This study revealed that there were minimal aroma/flavor differences among the ham treatments between 0 and 36 mg/ml, and that dry cured ham that was fumigated with SF was safe and met legal requirements for consumption.