J.E. Hayes

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.

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.

The effect of enhancement with salt, phosphate and milk proteins on the physical and sensory properties of pork loin

Pork loins were pumped to 110% of original weight with solutions containing 5.5% salt and 3.3% sodium tripolyphosphate, 5.5% salt and 3.3% β-lactoglobulin (β-lg) enriched fraction or 5.5% salt and 3.3% whey protein concentrate 80% (WPC80) for comparison with non-enhanced control loins. The enhancement of pork loins significantly increased (p<0.001) the tenderness and juiciness. Warner-Bratzler shear force values were lower (p<0.001) in enhanced then in non-enhanced control chops. The enhanced pork chops had a slightly higher overall flavour and overall acceptability to the control pork chops. Sensory analysis showed that β-lg enriched fraction and WPC80 can be used as replacement ingredients to reduce the amount of phosphate used in enhancement solutions, as they were comparable to salt/sodium tripolyphosphate (salt/STPP) enhancement solution. Consumers rated the tenderness, juiciness and taste of the enhanced chops significantly (p<0.001) higher then the control chops.

The effect of whey protein-enriched fractions on the physical and sensory properties of frankfurters

Four Beta-lactoglobulin (β-lg) enriched fractions containing different mineral contents were prepared and evaluated in frankfurters. Frankfurters were assessed for cook loss, water holding capacity (WHC), textural and sensory characteristics. The addition of the β-lg fractions reduced the cook loss (p<0.001) in comparison to the control (6.63% vs 3.98%). The fractions (β-lg 1 and 2) with the lowest calcium level significantly reduced WHC (p<0.01). The β-lg fractions had no detrimental effect on the sensory characteristics (p>0.05). All of the fractions increased the TPA value of hardness in comparison to the control (p<0.001) while the springiness decreased in the fractions (p<0.001) with the lowest mineral level. This study showed that the mineral composition of the β-lactoglobulin fractions affected cook loss, tenderness and hardness (TPA) of the frankfurters and the addition of the β-lactoglobulin enriched fraction did not affect the organoleptic quality of frankfurters in comparison to the control. This study shows the potential for next generation whey protein fractions and their application in meat products.

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.

Development of a modified dry curing process for beef

The development of a dry curing process using physical treatments to promote the diffusion of the cure ingredients was studied. Vacuum pulsing with and without tumbling, continuous vacuum, and tumbling only treatments were compared with a conventional static dry cure control method on beef M. supraspinatus. Vacuum tumble and tumble only treatments gave highest core salt content after 7 days conditioning (3.3% and 3.1%, respectively). All test treatments resulted in higher colour uniformity and lower % cook loss in comparison to control (P<0.001). The control and vacuum pulsed samples were tougher (P<0.001). Vacuum tumble and tumble only treatments gave higher acceptability (P<0.001). Based on these findings for M. supraspinatus, indicating that the vacuum tumble treatments gave the best results, further testing of this method was conducted using the M. biceps femoris in addition to the M. supraspinatus. Cured beef slices were stored in modified atmosphere packs (MAP) (80%N(2):20%CO(2)) for up to 28 day at 4°C. Redness (a(∗), P<0.001) decreased over storage time in M. biceps femoris. Vacuum tumble treatment increased (P<0.05) redness in M. supraspinatus. Results obtained demonstrate the benefits of vacuum tumbling over the other physical treatments as a method for accelerating the dry curing process, producing dry cured beef products with enhanced organoleptic quality and increased yields.

The effect of hot-boning and reduced added phosphate on the processing and sensory properties of cured beef prepared from two forequarter muscles

The functionality of pre-rigor beef was investigated in terms of the effects of phosphate reduction and curing of hot-boned meat on the processing and sensory properties of relatively low-value muscles, M. infraspinatus (IS) and M. pectoralis profundus (PP), from the forequarter. Muscles were excised within 90 min post-mortem (HB) or, from chilled carcasses, 24 h post-mortem (CB), and were injected to 115% of green weight with brine containing phosphate and were vacuum tumbled continuously for 2 h. Hot-boning gave lower total yield of cooked meat for both muscles. Hot-boned PP joints had slightly higher (P<0.05) cook loss than cold-boned. Reduction of added phosphate (from sodium tri-polyphosphate) from 0.3% to 0.15% of cured meat had detrimental effects on colour; joints containing the conventional 0.3% were lighter (P<0.001) and redder for both muscles. Hot-boning gave PP joints which were rated less tender by sensory panels, corresponding with higher (P<0.001) hardness TPA values, higher (P<0.05) Warner-Bratzler shear force (WBSF) values and shorter (P<0.05) sarcomere lengths. Effects of phosphate level and boning method were less in IS joints. In these, hot-boning gave products that were rated by sensory panel as slightly more tender but there was no effect on TPA or WBSF values. Furthermore, total yields from hot-boned products did not reflect the expected increase in functionality and reducing added phosphate during processing had a detrimental effect in binding and forming of joints.

Effects of organic tomato pulp powder and nitrite level on the physicochemical, textural and sensory properties of pork luncheon roll

Nine treatments of pork luncheon roll produced with three sodium nitrite levels (0, 0.05 and 0.1%) and three tomato pulp powder (TPP) levels (0, 1.5 and 3%) were assessed at three storage times (2, 7 and 14d). The effects of enrichment with TPP on composition (protein, fat, moisture and ash), pH, colour (CIE L*, a*, b*), nitrosomyoglobin (NOMb) content, lipid oxidation (TBARS), residual nitrite content, total viable count (TVC) texture profile analysis (TPA) and sensory analysis of cooked pork luncheon roll were investigated. Decreasing the level of nitrite increased (p<0.001) the pH, the NOMb value (p<0.001), lipid oxidation (p<0.001) and the residual nitrite content (p<0.001) and affected the colour of the cooked product. The reduction in nitrites had no effect on the composition and texture of the pork luncheon rolls. Adding TPP reduced (p<0.001) the pH and increased (p<0.001) the colour parameters a* and b* of both the raw luncheon roll formulation and the cooked luncheon roll product. TPP, particularly at 3% had a detrimental effect on the texture of pork luncheon rolls by decreasing hardness (p<0.001), gumminess (p<0.001) and chewiness (p<0.001) and increasing cohesiveness (p<0.001). The TBA value increased (p<0.01) with the three main factors (nitrite, TPP, day) but was in all cases well below the 2mg MDA/kg threshold. TVCs for all treatments and storage days were below the TVC limit for this type of cooked product. The pork luncheon roll formulated with 50mg nitrite and 1.5% TPP had similar or enhanced sensory attributes compared to the luncheon roll containing no TPP and a nitrite level of 100mg/kg of product.