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.

Performance of cold-set binding agents in re-formed beef steaks.

Four cold-setting gel-forming binding agents were compared in preparation of re-formed steaks from strips of each of two muscles, M. triceps brachii-caput longum (TB) from the shoulder, and M. pectoralis profundus (PP) from the brisket, of steer forequarter. The binding agents, which were commercial preparations, were Activa, containing transglutaminase enzyme as active ingredient, Fibrimex, containing the blood plasma fractions fibrinogen and thrombin, Textor, containing a modified starch, and alginate, containing sodium alginate and Ca(++). Binding of the cooked steaks and of slices therefrom, was satisfactory for the first three of the above but relatively weak for the alginate agent. Colour of steaks was affected by binder, in that Activa and Textor treatments gave lighter, redder and yellower (higher L*, a*, b* values) steaks than did the other two. Overall acceptability ratings by taste panels corresponded with those for flavour in the case of TB steaks, with Activa and Fibrimex samples scoring highest (P<0.05). For the less tender PP steaks, the highest acceptability score was for the Textor samples, reflecting their scoring best for tenderness. Warner-Bratzler shear force values corresponded with tenderness ratings in that Textor samples had lowest shear values for both muscles, but the differences were not significant. The overall conclusion, considering cohesion, appearance, cooking yield and sensory quality of the products, was that the Activa binder performed best and would facilitate the production of good-quality chilled re-formed beef steaks from various low-value beef muscles, and without addition of sodium chloride if so desired.

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.

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 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 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.

The immunogenicity and safety of intradermal hepatitis B vaccine.

BACKGROUND: One of the chief barriers to a greater use of hepatitis B vaccine is the high cost of the vaccine itself. A number of small research trials have shown that an adequate immune response can be induced at a much lower cost by administering one tenth of the vaccine using an intradermal technique. The purpose of this study was to ascertain whether these results could be replicated in a larger clinical trial. METHODS: Vaccine recipients included health care providers, police officers, and firefighters. Recipients were given 0.1 mL of plasma-derived hepatitis B vaccine intradermally on days 1, 30, and 180. Antibody response was measured on day 210, with seroconversion defined as a sample-to-negative (S/N) ratio of greater than or equal to 10. Any local and systemic side effects were documented. RESULTS: Six hundred sixteen individuals completed the vaccination series, and seroconversion occurred in 534 (86.7%). The rate of seroconversion in those younger than 40 years was 91.2% and in those 40 years and older was 75.1%. The mean S/N ratio was 154.9 (range 0 to 620) and decreased with increasing age (r = -.25, P = .0001). Side effects were largely limited to local reactions. CONCLUSIONS: The results support the use of the intradermal technique as a cost-effective alternative to the intramuscular route in individuals younger than 40 years. The intradermal technique may be used in older individuals if titers are obtained to assure seroconversion. Because of the restricted availability of the plasma-derived vaccine used in this study, similar trials with recombinant vaccine should be undertaken.

Mid-molecule parathyroid hormone assay comparison.

Parathyroid hormone (PTH) assays are becoming available to clinical chemistry laboratories for in-house use. We evaluated the clinical utility of two mid-molecule PTH assays in comparison to a sensitive but technically demanding component assay. A normal reference population, and an abnormal population including cases of primary and secondary hyperparathyroidism, hypoparathyroidism, and humoral hypercalcemia of malignancy were tested. PTH determinations with each assay system and total serum calcium determinations were done on all specimens. The Endocrine Metabolic Center (EMC) kit assay and the Immuno Nuclear Corp. (INC) kit assay demonstrated adequate standard curve reproducibility and precision for clinical use. With the aid of calcium determinations each assay performed well in the separation of abnormal patient groups, and in the separation of abnormal from normal PTH-calcium homeostasis. PTH values for the reference population differed among the three assays. The component assay and the EMC assay had a negative correlation with serum calcium, but the INC assay had a positive correlation with serum calcium.

Corticosteroid production in abetalipoproteinemia: evidence for an impaired response ACTH.

The concept that an inherent absence of plasma LDLs may be associated with a reduced synthesis of steroid hormones has been evaluated in two patients with ABL. Basal production of adrenal corticosteroids, assessed by the concentrations of serum cortisol and the rates of excretion of urinary 17OHCS and 17KS and urine free cortisol, was normal in both patients with ABL. Prolonged stimulation (24 to 36 hr) with ACTH, however, disclosed an impairment in adrenal corticosteroid production in both patients with ABL (as compared to normolipidemic controls), which was manifest by lower serum cortisol levels, reduced rates of urinary excretion of 17OHCS and 17KS and a marked decrease in the excretion of urine free cortisol. These results provide in vivo evidence to support the view that plasma LDLs serve as an important source of cholesterol for adrenal corticosteroid synthesis during prolonged stimulation with ACTH but show that a total absence of LDL does not impair adrenal steroidogenesis in the basal state.

Adrenal function in heterozygous and homozygous hypobetalipoproteinemia.

Corticosteroid synthesis in the human adrenal cortex requires a supply of cholesterol which can be derived from both local synthesis and the uptake of plasma lipoproteins. Studies with cultured adrenal cells have shown that such uptake is mediated through the interaction of plasma low density lipoproteins (LDL) and a specific cellular receptor (the LDL receptor). In the present study we have examined parameters of adrenal corticosteroid production in a patient with phenotypic abetalipoproteinemia (on the basis of homozygous hypobetalipoproteinemia) and in three of her relatives with inherently low levels of LDL (heterozygous hypobetalipoproteinemia). These studies sought to determine whether the absence of LDL or an inherent reduction in their plasma concentration results in alterations in corticosteroid production both under basal conditions and in response to prolonged stimulation with iv ACTH. Our results document normal parameters of corticosteroid production under basal conditions in both heterozygous and homozygous hypobetalipoproteinemia, but an impaired response to ACTH in the latter. This was manifested by significantly lower serum concentrations of cortisol as well as by reduced rates of excretion of 17OHCS, 17-ketosteroids, and urinary free cortisol during ACTH infusion. By inference, our results provide in vivo support for the view that plasma LDL serve as an important source of cholesterol for adrenal corticosteroid synthesis under conditions of sustained stimulation with ACTH.