ACCEPTABILITY OF VARIOUS GROUND BEEF AND PORK PRODUCTS EXTENDED WITH MECHANICALLY SEPARATED BEEF

Six blends of ground beef and six blends of ground pork containing 0, 15, 30, 45, 60 or 75% mechanically separated beef (MSB) were prepared. Also five batches of fermented sausage and spiced luncheon loaf containing 0, 5, 10, 15 and 20% MSB were formulated. Level of MSB was not related to juiciness rating or mealiness scores of cooked beef/MSB or pork/MSB patties. The level of MSB significantly affected overall eating satisfaction ratings for each blend of MSB patties. MSB at levels of 15% or more had a negative effect on flavor acceptability of cooked ground beef or pork. Fermented sausage products could be extended with only 5% MSB without creating defects in visual appearance or sensory properties. However, the inclusion of 20% MSB yielded a spiced luncheon loaf which was higher in eating quality than an all-beef control. The beef/MSB patties, fermented sausage, and spiced luncheon loaves containing 15% MSB were acceptable for visual appearance. Based on this study, MSB produced from a press type machine, can be blended up to 15% with ground beef, ground pork and sausage products without significantly decreasing raw appearance, sensory properties or storage life. Since MSB is a red meat product available at a similar low cost as textured vegetable protein, the red meat industry would benefit from expanded use of this high protein extender.     

DETECTION OF SPECIES ADULTERATION IN PORK PRODUCTS USING AGAR-GEL IMMUNODIFFUSION AND ENZYME-LINKED IMMUNOSORBENT ASSAY

Mixing undeclared species in meat products is illegal under food labeling regulations. This study compared the conventional agar-gel immunodiffusion (AGID) with the Enzyme-Linked Immunosorbent Assay (ELISA) for detecting species adulteration and assessed the species adulteration problem in raw ground pork products in Alabama retail markets. Forty-two ground pork and 87 fresh pork sausage samples collected throughout Alabama were examined by AGID and ELISA for four species: pork, beef, poultry and sheep. Using ELISA, 91 % of the ground pork samples were found to contain other meats while 71 % were found to be contaminated using AGID. Using ELISA, 54% of the sausage samples were found to contain undeclared species while none were found to be contaminated using AGID. The major adulterating species in the pork products was beef followed by poultry and sheep. Reliable analytical methods, such as ELISA, must be used as a regulatory tool to discourage the meat species adulteration problem in retail markets.     

EFFECT OF HIDE COLLAGEN ON THE AMINO ACID COMPOSITION OF BEEF PATTIES AND PORK SAUSAGE

Comminuted wet collagen from cattle hide was used to replace lean meat in a ground beef patty formulation at the 0,10 or 20% level and at the same level in a pork sausage formulation. The products were analyzed for amino acid composition by High Performance Liquid Chromatography. The products with collagen at all replacement levels showed a slight decrease in the essential amino acids but still retained approximately 75 to 85% of the total essential amino acids. Therefore, it was concluded that collagen from cattle hide may be used to replace a portion of the lean meat or fat meat in ground beef patties or pork sausage up to a 20% level while still providing much of the required dietary nutrition.     

SELECTED SENSORY AND CHEMICAL ATTRIBUTES OF CHICKEN BREAKFAST SAUSAGES FROM DIFFERENT ANIMAL FAT SOURCES

Four breakfast sausage formulations were prepared to contain: (1) chicken lean + chicken fat (CF), (2) chicken lean + beef fat (BF), (3) chicken lean + pork fat (PF), or (4) chicken lean + high-oleic pork fat (PO). Formulations were targeted to contain 15% fat. Acceptability, tenderness, juiciness and flavor scores for each of the formulations as measured by a consumer taste panel (n = 71), were not different (P> 0.05). Sausages prepared with CF had a higher (P < 0.05) cooking loss and lower fat content than those prepared with BF. Thibarbituric acid (TBA) values for PO were significantly lower than those containing BF, PF, or CF. Sausage products containing chicken fat exhibited the highest TBA values during 9 days of storage at 4°C. These results suggested that chicken, beef, pork or high-oleic fats can be used as the fat source in low-fat chicken breakfast sausages without affecting the product acceptability.     

Physical and Sensory Characteristics of Low-Fat Fresh Pork Sausage Processed with Various Levels of Added Water

The acceptability of low-fat pork sausage, formulated by replacing fat with added water, was studied. Six sausage blends, consisting of three fat levels (15, 25 and 35%) and two levels of added water (3 and 13%) were stratified across two packaging treatments, chubpacks or mechanically formed patties. Increased amounts of added water in low-fat sausage resulted in cooking losses, color and textural characteristics similar to control sausage. Sensory panel ratings did not differ between sausage formulated to contain 35% fat (3% added water) and those containing 15% fat. Acceptable lower fat pork sausage may be produced with 15% fat if water is used for the replacement of fat.     

FLAVOR ADJUNCTS FOR RESTRUCTURED PORK

Boneless prerigor pork shoulders were processed to restructured pork chops and formulated with 1% NaCl and .25% sodium tripolyphosphate (STP). Formulations included (1) 100% pork (C), (2) 95% pork - 5% rehydrated dried apples (A), (3) 95% pork - 5 % mushroom slurry (M), and (4) 99.98% pork -.02% liquid smoke extract (S). All samples were stored at -20°C until evaluation at 0, 14 and 42 days after packaging. Although the C chops received higher initial color scores, color of the A samples remained more stable during storage. The Hunter ‘a’ values followed a similar trend. Flavor enhancers and storage times that were evaluated had a minimal effect on product cohesiveness and tenderness. Rehydrated dried apples and the mushroom slurry appeared to be potential flavor enhancers; whereas, liquid smoke appeared to be a flavor protector by retarding oxidative rancidity development after frozen storage for 42 days.     

SODIUM LACTATE EFFECTS ON MICROBIAL, SENSORY, AND PHYSICAL CHARACTERISTICS OF VACUUM-PACKAGED PORK SAUSAGE

Vacuum-packaged fresh meat products held at refrigeration temperatures have limited shelf-life expectancies, often due to growth of anaerobic lactic acid-producing bacteria. Agents that can suppress the growth of this group are beneficial. Fresh pork sausage, formulated to contain 0%, 1%, 2%, or 3% sodium lactate (SL), was vacuum packaged and stored at 4C for 0, 10, 17, 24, and 31 days. A trained sensory panel evaluated pork, salty, sour, and bitter flavors. Aerobic total plate counts (APC), anaerobic total plate counts (AnPC), aerobic lactic acid producers (ALC), anaerobic lactic acid producers (AnLC), TBA values, and pH were determined. SL depressed APC, AnPC, and AnLC. Addition of 1% SL extended shelf-life of vacuum-packaged fresh pork sausage by 1 week compared to controls; samples containing 2% and 3% SL had not reached spoilage level (log₁₀ 7.0 CFU/g) at the conclusion of this study. Addition of SL increased salty taste and prevented loss of pork flavor over time, but had no effect on sour or bitter flavors.     

THE EFFECT OF FAT CONTENT AND FLAVOR ENHANCERS ON THE PERCEIVED SALTINESS OF COOKED 'BOLOGNA-TYPE' SAUSAGES

The effect of varying fat content (8, 12, 16, 20, 24 and 28%) on sausage perceived saltiness was studied using two different formulations, each with 1.2 and 2.0% NaCl. The formulations were made either by varying the proportions of lean pork and pork fat (Series 1) or by replacing water with pork fat on an equal weight basis (Series 2). The replacement of lean pork with pork fat increased the perceived saltiness of the sausages. When water was replaced with pork fat on an equal weight basis the perceived saltiness of the sausage, however, did not change. There was a strong negative correlation (P<0.01) between perceived saltiness and protein content thus suggesting a causative link between these factors. The flavor-enhancing properties of monosodium glutamate (MSG) and Ribotide (monosodium glutamate and 5'-ribonucleotides IMP and GMP) were also studied. MSG only slightly improved the sensory properties of the cooked sausages.     

PROCESSING PARAMETER EFFECTS ON TEXTURAL CHARACTERISTICS OF REDUCED-FAT PORK SAUSAGE

The objective of this study was to evaluate the effects of fat (10, 20, and 30%, postrigor; 10 and 30% pre-rigor), rigor state, plate size (3 and 5 mm), and mixing time (2 and 5 min) on cooking loss and instrumental texture characteristics of reduced-fat pork sausage. High-fat products exhibited greater cook loss and lower breaking force than low-fat products. Rigor state of raw materials had no effect on the characteristics evaluated. Increasing plate size and mixing time increased initial force required to compress a 2.5 cm core to 20% of its original height but had no effect on other characteristics. Reduction of fat content can be accomplished without addition of nonmeat ingredients by limiting plate size to 3 mm and mixing time to 2 min.     

FLAVOR ENHANCEMENT OF RESTRUCTURED PORK

Restructured pork chops were formulated using boneless pork shoulders, 1% NaCl and .25% sodium tripolyphosphate (STP). Experimental treatment included (1) 90% pork—10% dried apples (A), (2) 100% pork (C), (3) 90% pork—10% corn crumbs (CC), and (4) 90% pork—10% mushrooms (M). All samples were stored at —20°C until evaluation at 10 or 70d. Corn crumbs appeared to have less potential as an enhancer due to their adverse effect on color, overall appearance, texture, tenderness and flavor. Dried apples appeared to impair product cohesion more than overall product and color stability. Mushrooms appeared to be a viable source for flavor and appearance enhancement. Among nonmeat ingredients evaluated, none enhanced texture. Storage time had minimal effect on product tenderness.     

Effect of antioxidants on stabilization of meat products fortified with n-3 fatty acids

The effects of an n-3 oil emulsion, with and without added antioxidants, on lipid oxidation in n-3 polyunsaturated fatty acid (PUFA)-fortified meat products were studied. An emulsion of n-3 PUFAs was prepared (25% algal oil, 2.5% whey protein isolates, 10mM sodium citrate, 0.2% potassium sorbate, 500ppm of 70% mixed tocopherols, 100μM EDTA, pH 3, pasteurized at 75°C for 30min) and incorporated into fresh ground turkey, and fresh pork sausage (20% fat) to achieve a concentration of 500mg n-3 PUFA/110g meat. An antioxidant combination containing rosemary (0.2% w/w; radical quencher), citrate (0.5% w/w; sequestrant) and erythorbate (1g/kg product; reductant) was prepared and incorporated into ground turkey patties (5cm dia, 1.5cm thick) or fresh pork sausages (5cm dia, 1.5cm thick). Meat products were stored at 4°C or -18°C and analyzed for color (L*, a*, b* values), lipid oxidation (TBARS and lipid hydroperoxides) and n-3 PUFA profile. a* Values of refrigerated ground turkey patties decreased with storage, and an antioxidant combination effect was observed after 4 days (P<0.05). For fresh pork sausages at 4°C, control+antioxidant (CON+ANTI), and n-3+antioxidant (n-3+ANTI) groups showed greater a* values than controls (CON) indicating that the antioxidant combination stabilized meat color. TBARS and lipid hydroperoxides of both n-3 PUFA-enhanced meat products increased with storage (P<0.05); there were no significant changes in TBARS or lipid hydroperoxides for treatments containing the antioxidant combination (P<0.05). The actual level of n-3 PUFA incorporation in both meat products was greater than 87%; n-3 PUFA concentrations did not change within any treatment during storage (P>0.05). These results provide support for including antioxidant protection in n-3 PUFA fortified meat products.     

Effect of fat quality on sausage processing,texture, and sensory characteristics

Fresh pork sausage was manufactured to determine the effects of animal diet (unsaturated or control) and inclusion of corn oil during processing (0% and 14% fat replacement). Bologna was manufactured to investigate only diet effects. Processing, textural, sensory, visual, and storage characteristics were evaluated. Processing yield was improved 2.9 percentage units in fresh sausage but reduced 1.8 units in bologna in unsaturated compared with control diets. Break strength of fresh sausage was reduced 0.6 kg by oil inclusion. Both unsaturated fat and including oil during processing resulted in softer texture of fresh sausage, while increased unsaturation in bologna resulted in firmer or unchanged textural properties. Fresh sausage with oil was lighter colored (5.3 L* units increased) with more fat smearing. In fresh sausage, lipid oxidation remained below 1 mg/kg MDA during 12 weeks frozen storage. Overall, changes in fat quality minimally affected sausage quality, likely providing acceptable products to consumers.     

Free Amino Acids of Raw and Cooked Ground Beef and Pork

Ground beef and ground pork were cooked for 15 min on an electric griddle heated to a surface temperature of 121°C. Cooking reduced the total free amino acid (FAA) content from 25.23 to 17.60 mg/25g fresh weight in pork and from 32.77 to 30.09 mg/25g fresh weight in beef. Sixteen FAA were detected in both beef and pork; most individual FAA decreased during heating. Residues remaining after extraction of FAA from raw pork, when rehydrated (70% moisture) and heated (121°C, 15 min), contained only trace amounts of FAA. Free amino acids apparently were not produced under the cooking conditions employed in this study.     

Spray Dried Soymilk Used in Reduced Fat Pork Sausage Patties

Spray-dried soymilks (SDSM) prepared from standard and lipoxygenase-null soybeans were incorporated into reduced fat pork sausage (PS). Comparisons of fat content, tenderness and consumer acceptance of SDSM PS with cooked regular (～30% fat), lean (～13% fat) and car-rageenan (0.4%) formulations were made. SDSM mixtures had 50-60% less fat and 41% lower caloric content than regular PS. Protein content and cooking yield were higher in SDSM PS than in regular PS. Texture of lean PS was improved by addition of SDSM, without alteration of flavor. No differences in PS flavor were noted between SDSMs or among formulations.     

INFLUENCE OF FAT CONTENT AND PRESERVATIVES ON THE BEHAVIOR OF LISTERIA MONOCYTOGENES IN BEAKER SAUSAGE

Behavior of Listeria monocytogenes Scott A in pork liver sausage containing 22–67% fat, and antilisterial activities of sodium lactate, sorbic acid, potassium sorbate and sodium propionate were studied during storage at 4C and 10C. Commercial pork liver sausage batter (22% fat), alone and with additions of lard (15, 30, and 45% by weight) were tested. Concentrations of 1.8% sodium lactate, 0.1% sorbate as the acid or the potassium salt, and 0.2% sodium propionate were tested in heat sterilized sausage inoculated with a 24 h culture of the organism (10⁴ CFU/g). Fat content alone caused small reductions in cell numbers by the end of the storage periods: from log CFU/g of 9.9 to 9.4 after 14 days at 10C, and from 7.3 to 6.5 after 50 days at 4C in the basic sausage formulation and with 45% added fat, respectively. The inhibitory activities of lactate and propionate increased with increase in fat content, and were more pronounced at 4C, where the effects were listericidal. Inhibition by sorbic acid was least influenced by the fat content, and the potassium salt was less antilisterial than the acid.     

ADDITION OF CORN GLUTEN MEAL AND ZEIN TO GROUND PORK OF VARIOUS FAT PERCENTAGES1

Corn gluten meal and zein at levels of 0, 2.5 and 5% were added to ground pork of three fat percentages. Raw patties were analyzed for fat, moisture, protein contents and color. Selected patties, broiled to 77°C, were evaluated for proximate composition, total cooking loss, color and Instron compression. Five percent zein added to ground pork reduced cooking loss 4.2% when compared with ground pork without zein. Addition of corn gluten meal to pork did not influence yield. Instron compression values increased with the addition of zein and corn gluten meal. Increased fat altered the hue (increased hue angle due to increased b) of the interior of the cooked pork patties. Zein addition also increased the lightness of cooked pork patties. The addition of zein to ground pork patties decreased sensory tenderness and pork flavor intensity and increased off-flavor intensity.     

Low-fat meat products-technological problems with processing

Diet and health advice serve as a driving force to redirect the types of foods considered to be most beneficial in terms of improved health and quality of life for Americans. Although meat cuts have become leaner, products such as ground beef, fresh pork sausage, coarse ground sausages and emulsified sausages traditionally have higher levels of fat. However, these products offer the greatest opportunity for fat reduction by reformulation with fat substitutes. Fat replacements should contribute a minimum of calories to a product and should not be detrimental to organoleptic qualities. Most substitutes can be categorized as: leaner meats, added water, protein-based substitutes, carbohydrate-based substitutes and synthetic compounds, Reducing the fat content to ～10% often results in cooked ground beef that is bland and dry with a hard, rubbery or mealy texture. Reformulation with fat substitutes can cause a reduction in particle binding, darker product color, lack of beef flavor, reduced browning reactions and shorter microbiological shelf-life. Other problems that occur with low-fat (5-10%) fresh or cooked/smoked sausages are reduced cook yields, soft mushy interiors, rubbery skin formation, excessive purge in vacuum packages, shorter shelf-life and changes in sensory qualities after cooking or reheating. However, some combinations of fat replacements that mimic the mouthfeel and textural characteristics of fat offer potential for development of low-fat meat products.     

Low-Fat Fresh Pork Sausage Patty Stability in Refrigerated Storage with Potassiunn Lactate

Typical pork sausage patties (40% fat), low-fat (8%) control patties, and low-fat (8%) patties with 20% added water and 0.4% carrageenan were compared to identical treatments containing 2% potassium lactate. The lactate had no effect on percent discoloration or lean color during refrigerated aerobic storage. Sensory properties of pork sausage treatments were not affected by the lactate salt (P<0.05). Bacterial populations of low-fat pork sausage patties did not differ (P>0.05); however, the typical patties with 2% potassium lactate had lower (P<0.05) microbial numbers during refrigerated storage than typical fresh pork sausage. TBARS,‘L’,‘a’and‘b’values were unaffected by the potassium lactate (P>0.05).     

Amorphous cellulose gel as a fat substitute in fermented sausages

Fermented sausages were produced with 25%, 50%, 75% or 100% of their pork back fat content replaced by amorphous cellulose gel. The sausage production was monitored with physical, chemical and microbiological analyses. The final products were submitted to a consumer study, and the volatile compounds of the final products were extracted by solid-phase microextraction and analyzed by GC/MS. The reformulated fermented sausages had significant reductions in fat and cholesterol, and the volatile compounds derived from lipid oxidation were also reduced in the final products. These results suggest that the substitution of up to 50% of the pork back fat content by amorphous cellulose gel can be accomplished without a loss of product quality, enabling the production of fermented sausages with the levels of fat and cholesterol decreased by approximately 45% and 15%, respectively.