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.

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% ß-lactoglobulin (ß-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 ß-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.

Effect of pelvic suspension and cooking method on the processing and sensory properties of hams prepared from two pork muscles.

The effect of two hanging methods (Achilles and aitch-bone) and two cooking methods (normal and Delta-T (ΔT)) on the quality of cooked hams produced from two muscles, M. semimembranosus (topside) and M. biceps femoris (silverside) was examined. Pork sides were hung by the Achilles tendon (conventional) or the aitch-bone (pelvic suspension) 1 h post-slaughter and chilled for 24 h at 1 °C. The hams were steam-cooked using a 'normal' cooking cycle (cooked at 85 °C to a core temperature of 72 °C) or a 'ΔT' cycle (maintaining a constant difference, of 35 °C, between oven and core temperatures until the oven reaches 85 °C, whereupon the core is allowed to come up to 72 °C). Pelvic suspension increased (P⩽0.01) the brine uptake of silverside hams, by 2.6%, but not of topside. The ΔT cooking method had a significant effect (P⩽0.05) for both muscles, reducing cook losses by 2.3% units in the topside hams and 3.3% in the silverside hams, compared to the normal continuous cook. Pelvic suspension resulted in slightly (P⩽0.05) more tender and juicy hams from silverside but not from topside. Both hanging method (Achilles and Aitch-bone) and cooking method (normal and ΔT) affected silverside ham more than topside ham. The overall result was that a combination of pelvic suspension and ΔT cooking had a positive effect on the quality of cooked hams, particularly hams produced from the silverside.

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

Four Beta-lactoglobulin (ß-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 ß-lg fractions reduced the cook loss (p<0.001) in comparison to the control (6.63% vs 3.98%). The fractions (ß-lg 1 and 2) with the lowest calcium level significantly reduced WHC (p<0.01). The ß-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 ß-lactoglobulin fractions affected cook loss, tenderness and hardness (TPA) of the frankfurters and the addition of the ß-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.

Long-term effects of ad libitum low-fat, high-carbohydrate diets on body weight and serum lipids in overweight subjects with metabolic syndrome.

BACKGROUND: Overweight individuals with metabolic syndrome are at increased risk of type 2 diabetes and coronary vascular disease. Weight gain and features of the syndrome may be ameliorated by dietary intervention. OBJECTIVE: We investigated the effects of replacing one-quarter of daily fat intake by complex or simple carbohydrate on body weight and intermediary metabolism. DESIGN: Forty-six subjects with > or =3 metabolic syndrome risk factors were randomly assigned to receive a control diet; a low-fat, complex carbohydrate diet (LF-CC); or a low-fat, simple carbohydrate diet (LF-SC) for 6 mo. Thirty-nine subjects completed the trial. About 60% of daily dietary intake was provided free of charge through a grocery store. Energy intake was ad libitum. Body weight, body mass index (BMI), blood pressure, and blood lipids were measured at months 0, 2, 4, and 6. RESULTS: There was a significant diet x time interaction on body weight and BMI (P < 0.001). Weight loss was greatest with the LF-CC diet [change in body weight: control diet, 1.03 kg (NS); LF-CC diet, -4.25 kg (P < 0.01); LF-SC diet, -0.28 kg (NS)]. Total cholesterol decreased by 0.33 mmol/L, 0.63 mmol/L, and 0.06 mmol/L in subjects consuming the control, LF-CC, and LF-SC diets, respectively (difference between the LF-CC and LF-SC groups: P < 0.05). There were no significant changes in LDL cholesterol, whereas HDL cholesterol decreased over time in all 3 groups (P < 0.0001). Triacylglycerol concentrations were higher in the LF-SC group than in the other 2 groups (P < 0.05). CONCLUSIONS: A low-fat, high-polysaccharide diet in overweight individuals with abnormal intermediary metabolism led to moderate weight loss and some improvement in serum cholesterol. Increasing simple carbohydrates did not promote weight gain, but nor was there improvement in body weight or lipid profile.

The effect of injection level and cooling method on the quality of cooked ham joints.

The effect of cooling method and injection level on cooling rate, weight loss and quality of large cooked ham joints was investigated. Two cooling methods, vacuum (VC) and conventional (CC) and two injection levels (20 and 30%) were examined. VC reduced the cooling rate (70 °C to 4 °C) significantly in comparison to the CC (2.5 h vs. 12.5 h). Under these test conditions, VC conformed to recent safety guidelines for cooked meat joints of a reduction in temperature to 5 °C inside 10 h in comparison to CC. The injection rate had no affect on the cooling rate. Increased weight loss due to vacuum cooling was off-set by increasing the level of brine injection in pork legs from 20 to 30% and getting a yield after VC similar to that for CC hams injected at 20%. Injection rate had no affect on the sensory attributes but cooling method did; VC hams were slightly tougher (P<0.05) and drier (P<0.01) than CC hams. While VC hams injected to a 30% rate were less tender and juicy than CC hams injected at a 20% rate, as indicated by sensory scores and some instrumental texture parameters, they were similar in shear value and in overall acceptability.

Effect of some fat replacers on the release of volatile aroma compounds from low-fat meat products.

The effect of fat content and carbohydrate fat-replacers on the release of volatile odor compounds from beefburger, salami, and frankfurter has been investigated. The reduction in fat content in any of the three meat products studied resulted in a tendency toward an increase in the quantities of volatiles released in the headspace. Tapioca starch and maltodextrin appear to delay the release of certain classes of compounds selectively; for instance, tapioca starch appears to slow the release of some Maillard products while maltodextrin has a similar effect on terpenes. In contrast, oat fiber decreases the release of most of the compounds analyzed. Thus, the addition of carbohydrate fat-replacers to low-fat meat products could assist the flavor qualities of low-fat meat products by slowing down the release of odor compounds.

Effect of rapid and conventional cooling methods on the quality of cooked ham joints.

Three cooling regimes, vacuum (VC), blast (BC) and slow cooling (SC), were compared for their effect on cooling rate, weight loss and quality of large cooked ham joints. Vacuum cooling reduced the cooling rate (70-4°C) significantly (P<0.05) in comparison to the other methods; mean cooling times for cooked hams (5-6 kg) were 1.9 h for VC, 11.7 for BC and 14.3 for SC. However, VC gave an increased chill loss (P<0.05) of ca. 11% compared to ca. 4% for the other methods due to evaporative moisture loss. Sensory panels found that VC hams were tougher and less juicy (P<0.05). Shear force measurements and texture profile analysis also showed the vacuum cooling to have a toughening effect on the cooked ham. While vacuum cooling had an adverse effect on quality and yield, it was the only one that conformed to recent safety guidelines for cooked meat joints of a reduction in temperature to 5°C inside 10 h. The cooling conditions used do not reproduce full-scale industrial practice, however, the effects found serve as an indicator of the potential benefits and drawbacks of vacuum cooling for cooked meat joints.

Preparation of surimi-like extract from beef hearts and its utilisation in frankfurters.

Surimi-like material was prepared from beef heart and evaluated in commercial frankfurter (30% fat) recipes at levels of 3, 7 10 and 15% by weight replacing lean meat. The addition of the heart surimi at a 15% level reduced (p < 0.05) cook loss compared with the control (6.4% vs 7.5%). Shear force measurements on frankfurters showed that the control had the highest value (20.4 N(-1) g) and the 15% surimi treatment the lowest (p < 0.05) value (13.9 N(-1) g). Correspondingly, sensory analysis indicated that as the surimi-type material was added the tenderness increased (p < 0.05). Panellists found no off-flavours and all the treatments scored similarly to the control in terms of overall flavour. In terms of 'overall acceptability' panellists found treatments containing 7 and 10% heart surimi were preferable to the control. Surimi-type material from hearts can be used in frankfurter formulations up to 15% without impairing texture or flavour.