Nutritional and sensory quality of porcine raw meat, cooked ham and dry-cured shoulder as affected by dietary enrichment with docosahexaenoic acid (DHA) and α-tocopheryl acetate

The effects of dietary enrichment of pig diets with DHA from a marine source (Algatrium^®) and α-tocopheryl acetate on the nutritional and sensory characteristics of pork and pork products were evaluated. Raw and cooked hams, and dry-cured shoulders from pigs fed with three diets (control, control supplemented with 0.3% DHA plus 50 ppm α-tocopheryl acetate and control with 200 ppm α-tocopheryl acetate) were used. The treatments did not cause any significant differences in proteolytic and antioxidant enzyme activities, except on catalase (CAT) which increased significantly in raw hams from pigs fed DHA supplemented diets. Vitamin E accumulated in samples with α-tocopheryl acetate supplementation. DHA added to the diet increased the DHA level by 87% compared with the control treatment in both raw and dry-cured shoulders, and exceeded 82% in cooked hams. In consequence, the incorporation of the n − 3 source in the diet significantly reduced the n − 6/n − 3 ratio in all products. The ratio reduction ranged from 51% in dry-cured shoulders to 65% in cooked and raw hams.     

Effect of Antioxidants and Cooking on Stability of n-3 Fatty Acids in Fortified Meat Products

ABSTRACT: This study was carried out to determine the effect of processing and cooking on n-3 polyunsaturated fatty acid (PUFA) stability and to determine the efficacy of antioxidants (ANTI) to minimize lipid oxidation in cooked n-3 PUFA-fortified meat products. An emulsion of n-3 PUFAs (25% algal oil) was incorporated into ground turkey, pork sausages, or restructured hams (500 mg n-3 PUFA/110 g meat) with or without an "antioxidant cocktail" containing citrate (0.5% w/w), erythorbate (1 g/kg product), and rosemary (0.2% w/w). Ground turkey and pork sausages were frozen 2 d, then cooked to 71°C, and stored at 4°C for 2 d. Cooked, restructured hams were sliced, vacuum packaged, and stored at 4°C, or frozen and thawed with subsequent storage at 4°C. Treatments were CON (control), n-3 (n-3 PUFAs), CON + ANTI and n-3 + ANTI. Products were analyzed for color, lipid oxidation (TBARS and peroxide values), and n-3 PUFA profile. TBARS of n-3 PUFA-fortified treatments in ground turkey and pork sausages increased with storage ( P < 0.05); there were no changes in TBARS for CON + ANTI and n-3 + ANTI groups ( P > 0.05). For restructured hams nitrite curing appeared to delay lipid oxidation such that antioxidant treatment effects were unobservable ( P > 0.05). Overall recovery of n-3 PUFAs after heat processing was 69% to 85%, and there was no effect of storage on n-3 PUFA concentration in raw or cooked products ( P > 0.05). Sensory scores for n-3 treated restructured hams were lower than controls ( P < 0.05). Results suggested that cooking resulted in some losses of n-3 PUFAs in fortified meat products and that an "antioxidant cocktail" protected against lipid oxidation during subsequent storage in non-cured meat products.     

Varying the temperature of the liquid used for high-pressure processing of prerigor pork: effects on fresh pork quality, myofibrillar protein solubility, and frankfurter textural properties

The objective was to evaluate high-pressure processing (HPP) with varying liquid (water) temperatures on pork quality and textural properties of frankfurters. HPP pressurization liquid temperatures were 15.5 °C (HPP Low) and 29.4 °C (HPP Med). Analyses were conducted using paired boneless loins and paired boneless hams. Loins were evaluated for pH, purge loss, objective color, subjective color, firmness; and changes in color after a bloom period. Eight independent batches (2 batches each of HPP Low, paired untreated, HPP Med, and paired untreated) of frankfurters were manufactured from the outside portion of the ham and the knuckle. Both HPP treatments resulted in higher (P < 0.05) ultimate pH and less (P < 0.05) purge loss of the loin. Loin tenderness was not different among either HPP treatment temperature groups when compared to untreated controls except HPP Med chops were more tender (P = 0.02) than untreated controls. Salt-soluble protein extractability of inside ham muscles was lower (P < 0.05) for both HPP treatment levels when compared to untreated controls, but was not different between the 2 HPP treatment levels. Textural properties of frankfurters were not different for either HPP treatment group when compared to its respective untreated control for any parameter except springiness. HPP Low frankfurters had lower (P = 0.10) springiness values than untreated controls. Fracturability of HPP Med samples was lower (P = 0.12) than untreated controls. Overall, HPP caused higher ultimate pH and increased water-holding capacity, but did not affect tenderness of fresh meat or textural properties of frankfurters. PRACTICAL APPLICATION: HPP can be used on prerigor pork as means to improve fresh pork quality. Loins from HPP-treated pork sides had higher ultimate pH values and less package purge loss. Tenderness values were not affected positively or negatively by HPP treatment. The high pH and water-holding capabilities of treated samples have positive implications for further processing applications. Frankfurter textural properties suggest emulsified products can be made with pressurized pork without sacrifice to the textural profile.     

Quality of Restructured Hams Manufactured with PSE Pork as Affected by Water Binders

Restructured hams were made from modified food starch (MFS), kappa-carrageenan (k-c), isolated soy protein (ISP), and processed with different levels of PSE pork [100% Normal, 50% PSE/50% Normal, 100% PSE]. Hams were ground, tumbled for 2h with a brine, stuffed, and water cooked. Bind strength values decreased and expressible moisture increased with addition of PSE pork to the ISP and k-c treatments. Incorporation of MFS decreased bind strength and expressible moisture and increased yields in the 100P treatment. Results indicated MFS enhanced the water retention of PSE pork in a restructured product.     

Effect of cooking bag and netting packaging on the quality of pork ham during water cooking

As a preliminary test for combining water cooking with vacuum cooling in soup of pork ham, three package treatments were designed to study the effect of cooking bag and netting on the quality of water cooked ham, i.e. ham cooked with a cooking bag and without a cooking bag (single netting and double netting). For treatments without a cooking bag, the results indicated that there was no significant superiority of ham cooked with double netting compared with ham cooked with single netting on the processing efficiency and quality characteristics. Although the hams cooked with a bag performed better in some chemical retentions and pigment, the water contents were significantly lower than those hams cooked in single netting (P<0.05), and there was a higher shrinkage tendency compared with the hams cooked without a bag. For the processing characteristics and texture properties of pork ham, there were no significant differences observed among the treatments with and without a cooking bag in terms of the combined effect of cooking and cooling (P>0.05). By considering the safety, convenience, cost, and the recovery effect on the quality changes of ham during vacuum cooling in soup, cooking with single netting is a better choice for future research.     

Influence of PSE pork on the quality and economics of cooked, cured ham and fermented dry sausage manufacture

PSE pork (pH(1) ≤ 5·8) and non-PSE pork (5·8 < pH(1) ≤ 6·4) were used for cooked, cured ham production and, with beef, in a 48 52 mixture for fermented dry sausage manufacture. Technological yields of PSE and non-PSE hams were, respectively, 94·0 and 105·9% which corresponded to 5·0 FMK/kg loss for the PSE ham compared to the non-PSE ham. In addition, cooked PSE ham had a poorer organoleptic quality compared to non-PSE ham. However, PSE meat could be mixed with normal meat for the production of fermented dry sausage without quality defects.     

Chemical, Physical and Sensory Attributes of Pre- and Post-Chill Processed Hams and Bellies

Hams and bellies from 4 control carcasses and 12 conditioned carcasses were evaluated to determine the physical, chemical and sensory characteristics of pre- and post-chill processed hams and bellies. Processing yields, chemical analyses and sensory characteristics of the hams were not significantly affected by processing treatment. Final yields for the control, post-chill bellies were higher (P < 0.05) than those for pre-chill bellies. Except for differences in crispness, no differences in sensory attributes were noted for cooked bacon strips. Overall, hams and bellies from conditioned carcasses were comparable to cold processed hams and bellies in each variable evaluated in the study.     

Properties of Frankfurters Made From Electrically Stimulated Beef

Frankfurters (3 replications of 4.54 kg meat batches) were conventionally made. Paired sides from beef were used for control (NES) and electrically stimulated (ES) meats (clods, flanks and plates). All-beef frankfurters (100% ES beef or 100% NES beef) and beef-pork frankfurters (80% ES beef-20% pork or 80% NES beef-20% pork) were made. The pork was not electrically stimulated. Proximate composition within cut of beef (plate, flank, clod) was not affected (P > 0.05) by ES. However, ES clods had (numerically) greater percentages of expressible juice loss, greater percentages of salt-soluble protein and lower percentages of juice loss during cooking than did NES clods (not statistically different). Use of ES beef alone or in combination with 20% pork did not affect external visual color, off-flavor, overall desirability or processing shrinkage of frankfurters. ES may affect certain properties (raw and cooked muscles) as measured in the laboratory, but when these ES muscles are used to make frankfurters, no real advantages or disadvantages were suggested by this study.     

Acceptability of low-fat frankfurters as influenced by the feeding of elevated levels of monounsaturated fats to growing-finishing swine

The effects of high levels of oleic acid in the diet on the physical, chemical and sensory traits of frankfurters were examined. Frankfurters were formulated at three fat levels (10, 20 and 25%) from pork trimmings from each dietary treatment. The control frankfurters were the most springy, firm, flavorful and palatable and had the most intense flavor (P < 0·05). However, low-fat frankfurters produced from the high-oleate treatments were comparable to the control in all sensory characteristics (P > 0·05). The 10 and 25% fat frankfurters were rated highest and lowest, respectively, for juiciness, springiness, firmness, flavor, flavor intensity and overall palatability (P < 0·05). Sensory panelists detected off-flavors in the 25% fat frankfurters more frequently than in the 10% fat frankfurters (P < 0·05). 2-Thiobarbituric acid values were not affected by treatment and were acceptable after storage at 2°C for 24 weeks (P < 0·05).     

Effects of PSE on the quality of cooked hams

Meat quality comparisons were carried out on hams produced from pork legs showing evidence of PSE and normal pork legs. Quality measurements included drip loss, sliceability, cooking loss, TBARS analysis and colour evaluation (Hunter L, a, b). A total of 40 pork legs were selected from a commercial slaughtering plant, 20 from carcasses showing PSE and 20 from normal carcasses based on L, a, b, and pH values. Carcass pH taken between the third/fourth rib was measured 45 min, 90 min, and 24 h after slaughter. Using a Minolta colorimeter (Hunter L, a, b,), colour of the Longissimus dorsi muscle was measured 24 h after slaughter. PSE had an adverse effect on cooked hams in comparison to normal cooked hams with respect to driploss (P<0.01), cooking loss (P<0.01), sliceability (P<0.01), colour (P<0.05) and lipid oxidation (P<0.05). Cooked hams manufactured from severe PSE pork in this study had an estimated financial loss of 50% (IRL￡4.90) in comparison to those manufactured from normal pork (IRL￡9.80).     

Effect of salt and transglutaminase (TG) level and processing conditions on quality characteristics of phosphate-free, cooked, restructured pork shoulder

Six treatments of phosphate-free restructured cooked pork shoulder were produced with two salt levels (2% and 1%) and three transglutaminase levels (0%, 0.075% and 0.15%) under two processing conditions (72 °C/65 min and 78 °C/65 min). Salt level significantly affected (p < 0.05) the chemical composition, the cooking losses, the colour, the sensory attributes and the overall acceptability of the product. Transglutaminase level affected (p < 0.05) only the consistency and the overall acceptability. The processing conditions on the contrary, affected the moisture and the protein content, the cooking losses, the consistency and the juiciness of restructured cooked pork shoulder. Transglutaminase can be used at a level of 0.15% with reduced salt level (1%) and processing at 72 °C/65 min to produce phosphate-free restructured cooked pork shoulder with acceptable sensory attributes.     

PROCESSING CHARACTERISTICS AND YIELD OF PORK FRANKFURTERS MANUFACTURED FROM GILTS ADMINISTERED EXOGENOUS PORCINE SOMATOTROPIN

Eighteen gilts (75 kg) were injected daily with 0, 2.5, or 5 mg of porcine somatotropin (pST) for either 30 or 31 days prior to slaughter to examine the effects of dose of pST administration to swine on processing characteristics of frankfurters manufactured from pork. Frankfurters were manufactured from New York shoulders (NAMP #404) and formulated with fat from the same carcass to a final product target of 22% fat and 10% added water. Frankfurters from pST- treated gilts had lower smokehouse yields (0.9% decrease; P <.005) and greater shear force peak height (35.4% increase; P < 0.05) compared with the controls. The increased shear force required for skin failure of frankfurters manufactured from pork from pST-treated pigs was not readily explained by other differences due to treatment (e.g., cooking stability, batter proximate composition or salt soluble protein content; all P > 0.05)     

Control of Listeria monocytogenes on frankfurters and cooked pork chops by irradiation combined with modified atmosphere packaging

This study was conducted to investigate the efficacy of controlling Listeria monocytogenes on frankfurters and cooked pork chops with irradiation and modified atmosphere packaging (MAP) containing a high concentration of CO(2). Frankfurters and cooked pork chops were inoculated with a five-strain cocktail of L. monocytogenes and packaged in vacuum or high-CO(2) MAP. Irradiation was applied to each product at 0, 0.5, 1.0, or 1.5 kGy. No significant packaging effect was found for the radiation sensitivity of L. monocytogenes. Radiation D(10)-values for L. monocytogenes were 0.66 ± 0.03 and 0.70 ± 0.05 kGy on frankfurters and 0.60 ± 0.02 and 0.57 ± 0.02 kGy on cooked pork chops in vacuum and high-CO(2) MAP, respectively. High-CO(2) MAP was more effective than vacuum packaging for controlling the growth of survivors during refrigerated storage. These results indicate that irradiation and high-CO(2) MAP can be used to improve control of L. monocytogenes in ready-to-eat meats.     

PALATABILITY AND VISUAL CHARACTERISTICS OF HAMS AND LOIN CHOPS FROM SWINE TREATED WITH RACTOPAMINE HYDROCHLORIDE

This study was designed to evaluate the visual and palatability characteristics of boneless cured hams and fresh loin chops from pigs fed diets containing 0, 5, 10 or 20 ppm of the phenethanolamine, ractopamine hydrochloride (RAC). Sixty pigs were blocked by starting weight and randomly assigned to pens (four pigs/pen) within each of three blocks. Treatments were then randomly assigned to pens (six pens of the 0–ppm level and three pens each for the 5, 10 and 20 ppm RAC levels). Animals were slaughtered by weight block after approximately 48 days on trial. Fresh pork hams and loin sections (10–14th rib) were removed from the right side of the carcasses for subsequent analysis. Boneless hams were manufactured using commercial curing procedures. RAC had no effect (P > 0.05) on visual or palatability attributes of ham slices or boneless loin chops. Moisture content of the longissimus muscle from RAC treatments was lower (P < 0.05) than controls; however, this difference was small. These results indicate that RAC had no affect on the visual or palatability characteristics of boneless cured and smoked hams or fresh boneless pork loin chops.     

Physicochemical and sensory properties of healthier frankfurters as affected by walnut and fat content

This study evaluates the physicochemical and sensory properties of healthier frankfurters with 25% added walnut (WF) versus low-fat frankfurters (6% pork fat) (LF) and traditional frankfurters (18% pork fat) (NF). Results reveal that cooking losses were unaffected (p ? 0.05) by the formulation of frankfurters. The addition of walnut led to higher (p < 0.05) redness and yellowness values, while colour parameters did not differ significantly between LF and NF sausages. Frankfurters with added walnut (WF) presented higher (p < 0.05) hardness and chewiness values than LF and NF frankfurters. Differences in composition were also accompanied by changes in the microstructure of the gel/emulsions. Frankfurters with added walnut presented a flavour significantly different from meat and scored lower (p < 0.05) on texture preferences. However, all frankfurters scored the same for overall acceptability.     

EFFECTS OF AN AUTOLYZED YEAST ON PHYSICAL AND SENSORY PROPERTIES OF FRANKFURTERS

Three experiments were conducted to determine effects of autolyzed yeast on frankfurter firmness, flavor, and yields. Smokehouse yields of laboratory prepared frankfurters (Experiment #1) were not affected (P < 0.05) by addition of autolyzed yeast (1%). Commercially produced frankfurters containing 0%, 1.0%, or 1.5% yeast (Experiment #2) or 0%, 0.75% or 1.0% yeast (Experiment #3) were subjected to sensory and yield evaluations. Frankfurters from Experiment #2, with 1% autolyzed yeast were more firm (P < .10) than control frankfurters. Frankfurters from Experiment #3 with 0.75% and 1.0% autolyzed yeast were more firm (P < .01, P < .10) than controls. Vacuum packaged frankfurters containing yeast (Experiments #2 and #3), held 2, 4, or 6 weeks at 2–5°C, had less purge than their respective controls. Autolyzed yeast appeaers to enhance frankfurter flavor and firmness while reducing purge in vacuum packaged product.     

Textural Properties of Chicken Frankfurters with Added Collagen Fibers

Chicken frankfurters made with 0, 2, 4, 6, 8% added collagen fibers and 10, 15, 20, 25, 30% added water were evaluated for textural differences using a torsion test and sensory texture profile analysis. Frankfurters with high amounts of added water and low amounts of collagen fibers had lower shear stress values. Sensory analysis indicated that both collagen fibers and added water had significant influences (P<0.05) on hardness, springiness and juiciness. The addition of collagen fibers resulted in harder, springier, and less juicy frankfurters. Added water resulted in softer, less springy and juicier frankfurters. Response surface methodology demonstrated that for 2% added collagen, the optimum added water was ～20%.     

Comparison of antioxidant effects of milk mineral, butylated hydroxytoluene and sodium tripolyphosphate in raw and cooked ground pork

The antioxidant effects of 0.5-2.0% milk mineral (MM) was tested in raw and cooked ground pork stored at 2?°C or -20?°C, compared to butylated hydroxytoluene (BHT) and sodium tripolyphosphate (STP). TBA numbers were low and not different between raw meat treatments. TBA numbers were lower (P<0.01) for cooked treatments with MM or STP compared to controls or treatments with BHT. Experiments were also done to determine acceptability of pork samples with various TBA values, and to determine effect of holding time before serving on TBA values. Cooked pork patties held at 71?°C for 90 or 120 min had higher (P<0.05) TBA values than patties held for 0-60 min. Thus patties could be warmed for 60 min after cooking without significantly increasing TBA number. For paired-preference sensory testing, patties were cooked and stored at 2?°C for 0, 1, 2 and 3 days to obtain TBA numbers of 0.4, 1.5, 3.4 and 3.9 respectively. Panelists preferred (P<0.001) patties with TBA number <0.5, compared to patties with TBA numbers >1.4.     

SENSORY AND NUTRITIVE QUALITIES OF PORK STRIPS PREPARED BY THREE HOUSEHOLD COOKING TECHNIQUES1

The sensory and nutritive qualities of pork strips cooked by household broiling, microwaving, and stir-frying methods were determined. Fresh pork hams from two sources were cut into 0.5 × 2.5 × 4 cm strips having no separable fat. Pork strips were cooked by each method, three replications, to 66C internal temperature. Sensory qualities were evaluated by a 14-member trained panel consisting of lifelong Nebraska Caucasian women and men. Nutrients which Americans frequently consume in low quantities were measured. Pork strips that were cooked by stir-frying were significantly browner, more tender, and more juicy than those cooked by broiling or microwaving. Strips cooked by stir-frying were significantly more characteristic in flavor than those cooked by broiling but not microwaving. Significantly more vitamin B₆, thiamin, iron, magnesium, and zinc were retained in strips cooked by stir-frying than by the other two methods. Sensory attributes of pork strips cooked by stir-frying were generally more desirable and nutrient retention values higher than those cooked by microwaving or broiling.     

植物油预乳状液替代猪脂肪对法兰克福香肠品质特性的影响

将1 g/100 mL氧化绿原酸添加到以猪血浆蛋白水解物作为乳化剂所制备的水包油型乳状液中,以此获得高稳定性的植物油预乳状液。然后将该预乳状液以15%、30%、45%和60%的比例替代猪脂肪加入到法兰克福香肠中,探讨替代脂肪比例对香肠品质特性的影响。测定香肠的蒸煮损失、质构、色度以及水分迁移规律,同时测定肉糜的乳化稳定性和流变特性。结果表明,随着预乳状液替代比例的增加,香肠的蒸煮损失显著降低（P＜0.05）,硬度、咀嚼性、L*值和b*值显著增加（P＜0.05）,而弹性、黏结性、感官评价无显著变化（P＞0.05）。低场核磁研究结果发现,预乳状液替代比例的增加能够显著缩短香肠的弛豫时间（P＜0.05）,说明其能增强蛋白质网络对水分子的束缚能力。与此同时,随着预乳状液替代比例的增加,肉糜的乳化稳定性显著增加（P＜0.05）。另外,肉糜的流变学测定结果表明,随着预乳状液替代比例的增加能够显著提高肉糜在加热终点的储能模量（G’）和损失模量（G′′）,而且显著降低了相位角正切值（tanδ）（P＜0.05）。在法兰克福香肠的制作中猪脂肪能够被预乳状液部分替代,而且对香肠的感官无显著影响,尤其以45%的替代量为最佳。