Influence of level and duration of feeding polysaccharide (laminarin and fucoidan) extracts from brown seaweed (Laminaria digitata) on quality indices of fresh pork.

The effect of level (450 or 900 mg laminarin (L) and fucoidan (F) /kg feed) and duration (3 or 6 wks) of feeding a seaweed (Laminaria digitata) extract containing L/F on the quality of pork (longissimus thoracis et lumborum (LTL)) stored in modified atmosphere packs and on organ lipid stability was examined. Mechanisms of L/F antioxidant activity in LTL were evaluated. Plasma total antioxidant status, LTL pH, colour, microbiology and 'eating quality' sensory analysis were unaffected by dietary L/F. 'Visual' sensory descriptors (purchasing appeal and overall visual acceptability) were enhanced (p<0.05) in L/F450-3 LTL. Lipid oxidation was lower (p<0.05) in L/F450-3 and L/F900-3 LTL and reduced in L/F900-6 kidney homogenates. In cooked minced pork, lipid oxidation was not reduced by dietary L/F. Saturated fatty acids were lower (p<0.05) in L/F900-6 LTL. Results indicated L/F in pig diets for 3 weeks enhanced pork quality.

Influence of extraction technique on the anti-oxidative potential of hawthorn (Crataegus monogyna) extracts in bovine muscle homogenates.

Six extracts were prepared from hawthorn (Crataegus monogyna) leaves and flowers (HLF) and berries (HB) using solid-liquid [traditional (T) (HLFT, HBT), sonicated (S) (HLFS, HBS)] and supercritical fluid (C) extraction (HLFC, HBC) techniques. The antioxidant activities of HLF and HB extracts were characterised using in vitro antioxidant assays (TPC, DPPH, FRAP) and in 25% bovine muscle (longissimus lumborum) homogenates (lipid oxidation (TBARS), oxymyoglobin (% of total myoglobin)) after 24h storage at 4°C. Hawthorn extracts exhibited varying degrees of antioxidant potency. In vitro and muscle homogenate (TBARS) antioxidant activity followed the order: HLFS>HLFT and HBT>HBS. In supercritical fluid extracts, HLFC>HBC (in vitro antioxidant activity) and HLFC≈HBC (TBARS). All extracts (except HBS) reduced oxymyoglobin oxidation. The HLFS extract had the highest antioxidant activity in all test systems. Supercritical fluid extraction (SFE) exhibited potential as a technique for the manufacture of functional ingredients (antioxidants) from hawthorn for use in muscle foods.

Effect of varying the gas headspace to meat ratio on the quality and shelf-life of beef steaks packaged in high oxygen modified atmosphere packs.

Beef steaks (M. longissimus dorsi) were stored in modified atmosphere packs (MAP) (80% O2:20% CO2) with gas headspace to meat ratios of 2:1, 1:1 and 0.5:1 for 14 days at 4 °C. The pH, surface colour, texture and microbiology of beef steaks were unaffected (P>0.05) by varying the gas headspace to meat ratio. APLSR (ANOVA-partial least squares regression) and jack-knife uncertainty testing indicated that lipid oxidation (TBARS) was significantly positively correlated with days 10 (P<0.05) and 14 (P<0.001) of storage. Chemical and sensory detection of lipid oxidation in beef steaks were in agreement on day 14 of storage. The sensory quality and acceptability of beef steaks were similar in gas headspace to meat ratios of 2:1 or 1:1 and unacceptable in 0.5:1. Results indicate that pack size and gas volume can be reduced without negatively affecting fresh beef quality and shelf-life.

Effect of a brown seaweed (Laminaria digitata) extract containing laminarin and fucoidan on the quality and shelf-life of fresh and cooked minced pork patties.

A spray-dried seaweed extract containing laminarin (L, 9.3%) and fucoidan (F, 7.8%) (L/F extract) from brown seaweed (Laminaria digitata) was added directly to minced pork (M. longissimus dorsi) (LD) at levels of 0.01%, 0.1% and 0.5% (w/w). Fresh and cooked minced pork patties were stored in modified atmosphere packs containing 80% O2:20% CO2 and 70% N2:30% CO2, respectively, for up to 14 days at 4 °C. The L/F extract reduced the surface redness ('a*' values) of fresh patties as a function of concentration. The L/F extract (0.5%) exerted the greatest lipid pro-oxidant activity in fresh patties. The L/F extract (0.5%) significantly decreased (P<0.05) lipid oxidation in cooked patties. The L/F extract had no effect on the microbiological status, pH, water holding capacity (WHC) or cook loss of patties. Pork patties containing 0.01% L/F were preferred by sensory panellists. Further research will focus on the use of refined purified seaweed extracts in functional meat products.

Assessment of the ability of seaweed extracts to protect against hydrogen peroxide and tert-butyl hydroperoxide induced cellular damage in Caco-2 cells.

The ability of brown seaweed extracts, Ascophyllum nodosum, Laminaria hyperborea, Pelvetia canaliculata, Fucus vesiculosus and Fucus serratus to protect against tert-butyl hydroperoxide (tert-BOOH) induced stress in Caco-2 cells was investigated. Oxidative stress was determined by measuring alteration in the enzymatic activity of catalase (CAT) and superoxide dismutases (SOD) and cellular levels of glutathione (GSH). L. hyperborea, P. canaliculata and F. serratus significantly protected against tert-BOOH induced SOD reduction but did not protect against the reduction in CAT activity or the increased cellular levels of GSH. The ability of F. serratus and F. vesiculosus to protect against H(2)O(2) and tert-BOOH induced DNA damage was also assessed. The DNA protective effects of the two seaweed extracts was compared to those of three metal chelators; deferoxamine mesylate (DFO), 1,10-phenanthroline (o-phen) and 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (BAPTA-AM). F. serratus and F. vesiculosus significantly protected (P<0.05) against H(2)O(2) (50 µM) induced DNA damage but not tert-BOOH induced damage.

Addition of seaweed (Laminaria digitata) extracts containing laminarin and fucoidan to porcine diets: influence on the quality and shelf-life of fresh pork.

A seaweed extract containing laminarin (L) and fucoidan (F) (L/F) was manufactured from brown seaweed (Laminaria digitata) in spray-dried (L/F-SD) and wet (L/F-WS) forms. The effect of supplementation of pig diets with L/F-SD and L/F-WS (L, 500 mg/kg feed; F, 420 mg/kg feed) for 21 days pre-slaughter, on quality indices of fresh M. longissimus dorsi (LD) steaks was examined. Susceptibility of porcine liver, heart, kidney and lung tissue homogenates to iron-induced (1mM FeSO4) lipid oxidation was also investigated. Dietary supplementation with L/F did not increase plasma total antioxidant status (TAS). In LD steaks stored in modified atmosphere packs (80% O2:20% CO2) (MAP) for up to 15 days at 4 °C, muscle pH, surface colour (CIE 'L*' lightness, 'a*' redness and 'b*' yellowness values) and microbiology (psychrotrophic and mesophilic counts, log CFU/g pork) were unaffected by dietary L/F. In general, levels of lipid oxidation (TBARS, mg MDA (malondialdehyde)/kg pork) followed the order: C>LF-SD>L/F-WS. A statistically significant reduction in lipid oxidation (P<0.05) was observed in LD steaks from 75% of pigs (n=6) fed with L/F-WS compared to controls. Iron-induced lipid oxidation increased in liver, heart, kidney and lung tissue homogenates over the 24h storage period and dietary L/F-WS reduced lipid oxidation to the greatest extent in liver tissue homogenates. Results demonstrate potential for the incorporation of marine-derived bioactive antioxidant components into muscle foods via the animal's diet.

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 microg/g muscle), sesamol (250 and 500 microg/g muscle), ellagic acid (300 and 600 microg/g muscle) and olive leaf extract (100 and 200 microg/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% O(2):20% CO(2)) (MAP) aerobically at 4 degrees 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.

Evaluation of the effects of selected phytochemicals on quality indices and sensorial properties of raw and cooked pork stored in different packaging systems.

The effects of lutein (100, 200mug/g muscle), sesamol (250, 500mug/g muscle), ellagic acid (300, 600mug/g muscle) and olive leaf extract (100, 200mug/g muscle) on lipid oxidation (thiobarbituric acid-reactive substances TBARs), colour (CIE L *, a *, b *), pH, texture profile analysis (TPA), water holding capacity (WHC), cooking losses and sensorial properties of fresh and cooked pork patties were investigated. Raw and cooked minced pork (M. longissimus thoracis et lumborum) containing added lutein, sesamol, ellagic acid or olive leaf extract were stored aerobically or in modified atmosphere packs (MAP) for up to 8 and 12days, respectively. Lutein, sesamol, ellagic acid and olive leaf extract had no significant effect on microbial status, cook loss, pH or WHC. Lipid oxidation was reduced (P<0.001) in raw and cooked pork patties stored in aerobic packs and in MAP following addition of sesamol, ellagic acid and olive leaf extract. Antioxidant effectiveness in raw and cooked patties was in the order: sesamol=ellagic acid>olive leaf extract>lutein. Lutein increased (P<0.001) b * yellowness values in raw pork patties. Addition of lutein, sesamol, ellagic acid and olive leaf extract to pork had no detrimental effects on the organoleptic properties of cooked patties but altered (P<0.05) instrumental textural attributes. Results highlight the potential of using natural functional ingredients in the development of functional pork products with enhanced quality and shelf-life.

The effect of lutein, sesamol, ellagic acid and olive leaf extract on lipid oxidation and oxymyoglobin oxidation in bovine and porcine muscle model systems.

The effect of lutein (100, 200, 300µg/ml), sesamol (500, 1000, 2000µg/ml), ellagic acid (300, 600, 900µg/ml) and olive leaf extract (100, 200, 300µg/ml) on oxymyoglobin oxidation and lipid oxidation in bovine and porcine muscle model systems (25% M. longissimus thoracis et lumborum homogenates) was examined. Radical scavenging activity, using the DPPH assay, and iron-chelating activities of lutein, sesamol, ellagic acid and olive leaf extract were assessed at concentrations ranging from 200 to 1000ppm. The radical scavenging activity was of the order: ellagic acid>sesamol>olive leaf extract>lutein. None of the natural antioxidants examined exhibited iron chelating activity. Following induced lipid oxidation (FeCl(3)/sodium ascorbate addition), lipid oxidation and oxymyoglobin oxidation were measured after 24h at 4°C. In bovine and porcine muscle model systems, lipid oxidation decreased (P<0.001) following addition of each of the natural antioxidants relative to the control and antioxidant potency followed the order: sesamol>ellagic acid>olive leaf extract>lutein. Ellagic acid and olive leaf extract decreased oxymyoglobin oxidation (P<0.001) while sesamol increased oxymyoglobin oxidation in both systems. The natural antioxidants examined may have applications in the development of nutritional enhanced meat products with enhanced shelf-life characteristics.

Addition of grape seed extract and bearberry to porcine diets: Influence on quality attributes of raw and cooked pork.

The effect of supplementation of pig diets with grape seed extract (GSE) (100, 300, 700mg/kg feed) and bearberry (BB) (100, 300, 700mg/kg feed) for 56 days pre-slaughter, on the oxidative stability and quality of raw and cooked M. longissimus dorsi (LD) was examined. Susceptibility of porcine liver, kidney and heart tissue homogenates to iron-induced (1mM FeSO(4)) lipid oxidation was also investigated. In raw LD steaks, stored in modified atmosphere packs (75% O(2):25% CO(2)) (MAP) for up to 16 days at 4°C, surface lightness (CIE 'L' value), redness (CIE 'a' value), lipid stability (TBARS, mg MDA (malondialdehyde)/kg muscle) and pH were not significantly affected by supplemental GSE or BB. Similarly, the oxidative stability and sensory properties of cooked LD steaks, stored in MAP (70% N(2):30% CO(2)), for up to 28 days at 4°C, were not enhanced by dietary GSE or BB. Iron-induced lipid oxidation increased in liver, kidney and heart tissue homogenates over the 24h storage period and susceptibility to oxidation followed the order: liver>heart>kidney. Dietary GSE or BB did not significantly reduce lipid oxidation in tissue homogenates. Potential reasons for the lack of efficacy of supplemental GSE and BB on pork quality were explored.

Enhancement of the nutritional status and quality of fresh pork sausages following the addition of linseed oil, fish oil and natural antioxidants.

Fresh pork sausages (pork shoulder, pork back fat, water, rusk and seasoning) were manufactured where 15% of the pork back fat was substituted with linseed oil (LO) or fish oil (FO). Green tea catechins (GTC) and green coffee antioxidant (GCA) were added to both LO (LGTC 200 and LGCA 200) and FO (FGTC 200 and FGCA 200) substituted sausages at a level of 200mg/kg. Raw and cooked pork sausages were either over-wrapped with oxygen permeable film (aerobic storage) or stored in modified atmosphere packages (MAP) containing 80% O(2):20% CO(2) or 70% N(2):30% CO(2), respectively for 7 days at 4°C. Effects on fatty acid profiles, lipid oxidation, colour and sensorial properties were investigated. α-Linolenic acid increased from 1.34% (control) to 8.91% (LO) and up to 11.2% (LGTC 200 and LGCA 200). Addition of fish oil increased levels of EPA from 0.05% (control) to 2.83% (FO), 3.02% (FGTC 200) and 2.87% (FGCA 200) and DHA levels increased from 0.04% (control) to a maximum of 1.93% (FGTC 200). Lipid oxidation was low in raw and cooked linseed oil containing sausages. GTC (200mg/kg) significantly (P<0.05) reduced lipid oxidation in raw fish oil containing sausages after 7 days of storage. Colour parameters in raw pork sausages were unaffected by the packaging atmosphere. L(∗) lightness values were lower (P<0.05) in LGTC 200 and a(∗) redness values lower (P<0.05) in LGTC 200 and FGTC 200 after 7 days of storage. Sensory scores of cooked pork sausages were unaffected by linseed oil addition. Flavour and overall acceptability scores in cooked fish oil containing sausages were improved by GTC addition. Results obtained demonstrate potential for the production of nutritionally enhanced fresh pork sausages.

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 (log(10)CFU colony forming units/g pork) and sensorial properties of cooked pork patties was investigated. GSE (0-1000µg/g muscle) and BB (0-1000µg/g muscle) were added to raw pork (M. longissimus dorsi) patties which were stored in modified atmosphere packs (MAP) (75% O(2):25% CO(2)) for up to 12 days at 4°C. Cooked pork patties were stored in MAP (70% N(2):30% CO(2)) 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.

An assessment of dietary supplementation with tea catechins and rosemary extract on the quality of fresh beef.

The effect of supplementation of beef cattle diets with tea catechins (TC) (1000mg/animal/day) and rosemary extract (RE) (1000mg/animal/day), for 103 days preceding slaughter, on the oxidative stability of M. longissimus dorsi (LD) steaks was evaluated. Dietary supplementation with TC and RE did not increase plasma total antioxidant status (TAS), LD α-tocopherol concentrations or pH. In LD steaks stored aerobically or in modified atmosphere packs (80% O(2):20% CO(2)) (MAP) for up to 8 days at 4°C, surface redness (CIE 'a' redness value) and lipid stability (TBARS, mg MDA (malondialdehyde)/kg muscle) were not significantly improved as a result of supplementation with TC and RE. Similarly no improvement in the sensory properties and lipid stability of cooked LD slices, stored aerobically or in 30% CO(2):70% N(2) for up to 11 days at 4°C, was observed. An in vitro fermentation study demonstrated that TC and RE were not fermented to any great extent under simulated rumen conditions. Direct addition of TC (1000ppm) and RE (1000ppm) significantly (P<0.05) improved the colour and lipid stability in LD patties stored in 80% O(2):20% CO(2) for up to 8 days at 4°C, thus, demonstrating the antioxidant potential of TC and RE supplements employed in the present study.

Past, current and potential utilisation of active and intelligent packaging systems for meat and muscle-based products: A review.

Interest in the use of active and intelligent packaging systems for meat and meat products has increased in recent years. Active packaging refers to the incorporation of additives into packaging systems with the aim of maintaining or extending meat product quality and shelf-life. Active packaging systems discussed include oxygen scavengers, carbon dioxide scavengers and emitters, moisture control agents and anti-microbial packaging technologies. Intelligent packaging systems are those that monitor the condition of packaged foods to give information regarding the quality of the packaged food during transport and storage. The potential of sensor technologies, indicators (including integrity, freshness and time-temperature (TTI) indicators) and radio frequency identification (RFID) are evaluated for potential use in meat and meat products. Recognition of the benefits of active and intelligent packaging technologies by the food industry, development of economically viable packaging systems and increased consumer acceptance is necessary for commercial realisation of these packaging technologies.

Effects of dietary supplementation with vitamin E and organic selenium on the oxidative stability of beef.

The effects of supplementation of beef cattle diets with organic Se (0.3 mg/kg) and vitamin E (300 I.U. alpha-tocopheryl acetate/kg feed), for 55 d preceding slaughter, on the antioxidant status and oxidative stability of muscle was examined. Dietary vitamin E supplementation led to an increase (P < 0.05) in plasma, and longissimus muscle alpha-tocopherol levels. In minced longissimus muscle stored in 80% 02:20% CO2, lipid and oxymyoglobin oxidation were lower (P < 0.05) in muscle from vitamin E-supplemented animals compared with unsupplemented animals. Dietary Se supplementation did not significantly affect muscle Se levels, glutathione peroxidase activity, or susceptibility to lipid and oxymyoglobin oxidation in the presence or absence of vitamin E. Covariance analysis indicated that, in addition to muscle alpha-tocopherol, differences in muscle glutathione peroxidase activity, and pH could account for variation in the susceptibility of muscle to lipid and oxymyoglobin oxidation.

The effect of oxygen level and exogenous α-tocopherol on the oxidative stability of minced beef in modified atmosphere packs.

The effect of oxygen level (20, 40, 60 and 80%) in modified atmospheres on the oxymyoglobin content of intact and minced beef (M. semimembranosus, SM) was evaluated. There was no significant difference in the oxymyoglobin content of minced SM stored for up to 4 days in modified atmosphere packs containing 20, 40, 60 or 80% O(2). After 7 days, oxymyoglobin in minced SM decreased significantly (P⩽0.05) with decreasing oxygen level but by day 10 all samples had similarly low oxymyoglobin contents. Lipid oxidation increased significantly (P⩽0.05) between day 7 and 10 of storage in minced SM stored in modified atmospheres containing 40, 60 or 80% O(2). Oxymyoglobin and lipid oxidation occurred in intact SM but the extent of oxidation was lower than for minced SM. Exogenous α-tocopherol, dispersed in olive oil and added to minced SM (300 and 3000 mg α-tocopherol/kg lipid), had no significant effect on Hunter 'a' values when the samples were stored in low (20%) or high (80%) oxygen atmospheres. Exogenous α-tocopherol addition led to a significant reduction in lipid oxidation (P⩽0.05) in minced SM stored in high but not in low oxygen atmospheres.

Colour-stabilising effect of muscle vitamin E in minced beef stored in high oxygen packs.

Minced beef samples stored in high oxygen modified atmosphere packs (80% O(2):20% CO(2)) were evaluated for colour stability during refrigerated storage. The oxymyoglobin content and surface redness (Hunter 'a' value) of m. biceps femoris samples, previously frozen and minced, were significantly lower in samples with a mean vitamin E (α-tocopherol) content of 2.5 µg g(-1) compared with samples with 3.3, 3.9 or 5.5 µg g(-1) after 4, 6 and 8 days of storage at 4 °C. Lipid oxidation was significantly higher in the beef samples with the low vitamin E content compared with the other groups indicating that a likely mechanism for the colour-stabilising effect of vitamin E is through its action as a lipid antioxidant.