Effects of ascorbic and citric acid on beef lumbar vertebrae marrow colour.

Citric acid was evaluated as a way of improving ascorbic acid's ability to stabilize beef lumbar vertebrae colour in high-oxygen packaging (MAP; 80% O(2)/20% CO(2)). Vertebrae were treated with citric acid (1%, 3%, or 10%), ascorbic acid (1%, 3%, or 10%), or a combination of both. Citric acid demonstrated no positive effects (P>0.05), compared with ascorbic acid, which inhibited (P<0.05) discolouration throughout the 7d display. Although ascorbic acid inhibited discolouration (visual colour and a(∗); P<0.05), 3% and 10% ascorbic acid were most effective. However, if vertebrae are displayed for less than 7d, there may be no significant colour-stabilizing advantages associated with increasing ascorbic acid from 3 to 10%. The significant oxidizing effects of citric acid at 10% were reversed (P<0.05) by ascorbic acid. Combining citric and ascorbic acid had no synergistic affect (P>0.05) on vertebrae colour.

Comparison of ascorbic acid and sodium erythorbate: Effects on the 24h display colour of beef lumbar vertebrae and longissimus lumborum packaged in high-oxygen modified atmospheres.

Sodium erythorbate and ascorbic acid were compared as a means to stabilize surface colour of bone-in beef steaks in high-oxygen modified atmosphere (80% oxygen and 20% carbon dioxide). Bone-in strip loins (n=8) were fabricated into 1.9-cm thick steaks, of which both the lumbar vertebrae and longissimus lumborum were topically treated with either ascorbic acid or sodium erythorbate (0, 0.05, 0.1, 0.5, 1.0, or 1.5%, wt/wt basis). Colour (L(∗)a(∗)b(∗)) was evaluated before treatment and 24h after packaging (display at 1°C). Sodium erythorbate was as effective as ascorbic acid for inhibiting vertebrae discolouration (P>0.05). Either reducing agent at 0.5, 1.0, or 1.5% improved (P<0.05) vertebrae redness (compared with 0%, 0.05% and 0.1%). No detrimental effects on muscle colour were observed. When selecting antioxidants intended for bone-in beef steaks displayed in high-oxygen packaging, sodium erythorbate may be a cost effective substitute for ascorbic acid.

Effects of total iron, myoglobin, hemoglobin, and lipid oxidation of uncooked muscles on livery flavor development and volatiles of cooked beef steaks.

Infraspinatus (IN), gluteus medius (GM), and psoas major (PM) steaks were obtained from A- and B-maturity carcasses with either high (⩾6.0) or normal (⩽5.7) pH, and either Slight or Small marbling. Steaks were vacuum aged either 7, 14, 21, or 35d postmortem, and were broiled and served to a highly trained, flavor-profile sensory panel. Steaks with livery flavor were analyzed by gas chromatography/mass spectrometry for flavor compounds. Steaks aged 7 or 35d postmortem were analyzed for myoglobin (Mb) and hemoglobin (Hb) concentrations and for total iron (Fe) (35 d steaks only). The IN had greater Fe (P<0.05) than did the GM or PM. Livery flavor increased (P<0.05) and beef flavor identification decreased (P<0.05) in the GM as Fe increased. The PM had the lowest (P<0.05) Mb/Fe ratios and highest (P<0.05) Hb/Fe ratios. Several statistically significant, but relatively low correlations between 16-, 17-, and 18-carbon chain fatty acids and livery flavor resulted. Thirteen volatile compounds had higher concentrations in steaks with livery flavor than in those without livery flavor. Livery flavor development is a complex trait that can be affected by concentrations of total Fe, Mb, and fatty acids, but the relationships are relatively low.

Flavor characterization of top-blade, top-sirloin, and tenderloin steaks as affected by pH, maturity, and marbling.

Little information is available in the literature on the interrelationships and interactions among pH, aging time, marbling, and maturity on the flavor profile of some beef muscles commonly used for steaks. To investigate these effects on beef flavor, the infraspinatus (top-blade steak) from the chuck clod, the gluteus medius (top-sirloin steak) from the sirloin, and the psoas major (tenderloin steak) from the loin were obtained from A- (n = 80) and B-maturity (n = 60) carcasses with either Slight (n = 68) or Small (n = 72) marbling, and with either normal (< or = 5.7; n = 80) or high (> or = 6.0; n = 60) pH. Muscles were selected from two commercial processing plants at six different sampling times to evaluate factors that affect the flavor profile of cooked beef steaks. Muscles were vacuum-aged for 7, 14, 21, or 35 d, and a highly trained, flavor-profile sensory panel evaluated charbroiled steaks from these muscles. Numerous statistical interactions (P < 0.05) were detected for flavor attributes of the different muscles. In general, muscles from high pH (dark cutting) carcasses had less typical beef flavor identity and less brown-roasted flavor than those from carcasses with normal pH. Aging longer than 21 d generally decreased beef flavor identity. Top-blade steaks generally had less intense beef flavor identity and more intense bloody/serumy flavor than did top-sirloin and tenderloin steaks. Tenderloin and top-sirloin steaks of normal pH generally had the most brown-roasted flavor, especially when aged 21 d or less. Small degree of marbling generally resulted in a more rancid flavor compared with Slight marbling, but marbling had no other appreciable effects on the flavor profile. Aging steaks for 35 d increased (P < 0.05) the metallic flavor compared with aging for only 7 or 14 d. Top-sirloin steaks had a more intense (P < 0.05) sour flavor than did top-blade steaks, and steaks from carcasses with a high pH were more rancid (P < 0.05) than steaks from carcasses with normal pH. Vacuum-aging top-blade, top-sirloin, and tenderloin steaks to 21 or 35 d postmortem generally increased metallic and rancid flavors and increased sour flavor in top-sirloin steaks that were high in pH.

Beef quadriceps hot boning and modified-atmosphere packaging influence properties of injection-enhanced beef round muscles.

Two experiments were conducted to examine the effects of hot boning, modified atmosphere packaging, and injection enhancement on the oxidative and sensory properties of beef round muscles. The beef knuckle (quadriceps muscles) was partially hot boned within 1.5 h postmortem from one randomly selected side of each beef carcass (n = 14), whereas the quadriceps on the opposite side remained intact throughout a 48-h chilling period. At 5 d postmortem, biceps femoris, semimembranosus, vastus lateralis, and rectus femoris muscles from both hot- and cold-boned sides were injected with an enhancement solution consisting of water, salt, phosphate, and natural flavorings (rosemary) at either 6 (Exp. 1) or 10% (Exp. 2) of fresh muscle weight. Enhanced muscles were then processed into 2.54-cm-thick steaks, which were allotted randomly to high-oxygen (HiOx; 80% O2:20% CO2) or ultra-low oxygen (LoOx; 80% N2:20% CO2) modified atmosphere packaging. Regardless of hot boning or enhancement, steaks packaged in LoOx had lower thiobarbituric acid-reactive substances values (P < 0.05), more beef flavor intensity (P < 0.05), fewer off flavors (P < 0.05), and were more tender (P < 0.05) than steaks packaged in HiOx. Hot boning the knuckle had no effect on oxidative (P > or = 0.99) and sensory properties (P > or = 0.85). Increasing the level of injection enhancement from 6 to 10% introduced more rosemary and phosphate into the muscles, thereby decreasing the extent of oxidation, but also imparting a nontypical beef flavor. Packaging in LoOx atmosphere offered the optimal result of decreased oxidation and improved tenderness, without detriment to flavor. Injection enhancement (both 6 and 10%) created off-flavors attributable to the enhancement solution; however, the 10% injection seemed to offer more resistance to lipid oxidation.

Exclusion of oxygen from modified atmosphere packages limits beef rib and lumbar vertebrae marrow discoloration during display and storage.

Visual and instrumental color (L*a*b* and reflectance from 400 to 700 nm) were used to evaluate packaging atmosphere as a way of minimizing beef marrow discoloration. In experiment 1, rib ends (n=24) packaged in 80% O(2)/20% CO(2) discolored more than ribs packaged in 100% N(2), which resulted in a relatively stable purplish marrow color through a 7-day display at 1 °C. In experiment 2, lumbar vertebrae (n=10) packaged in 80% O(2)/20% CO(2) had a rapid and significant discoloration within 24 h after packaging, likely because of the formation of methemoglobin. Conversely, vertebrae packaged in 80% N(2)/20% CO(2) and 0.4% CO/30% CO(2)/69.6% N(2) remained color stable during 2 and 6 weeks of storage at 4 °C, respectively. Exclusion of oxygen from MAP packages and the addition of low concentrations of CO minimized beef rib and lumbar vertebrae discoloration compared with high-oxygen MAP.

Accelerated chilling and modified atmosphere packaging affect colour and colour stability of injection-enhanced beef round muscles.

Beef knuckles were partially hot-boned within 1.5 h postmortem. Biceps femoris (BF), semimembranosus (SM), vastus lateralis (VL), and rectus femoris (RF) muscles were injection enhanced at 6% (experiment 1) or 10% (experiment 2) of non-injected weight and packaged in a high- (HiOx; 80% oxygen and 20% carbon dioxide) or ultra-low oxygen (LoOx; 80% nitrogen and 20% carbon dioxide) modified atmosphere. Hot boning accelerated chilling in all beef round muscles investigated. This resulted in a darker initial beef colour and darker visual colour during display for the BF, RF, and VL, as well as more uniform BF and knuckle steak colour. RF and VL, in experiments 1 and 2, respectively, had the most improved colour and colour stability. Steaks in HiOx MAP had longer colour life in display than steaks that had been in LoOx. Partially removing the beef knuckle early postmortem is a practical process that will improve colour and colour stability of beef round muscles.

Ascorbic acid minimizes lumbar vertebrae discoloration.

Ascorbic acid was evaluated as a way of preventing bone discoloration. In experiment 1, beef bone-in t-bone steaks (lumbar vertebrae and longissimus) were treated with 0%, 0.05%, 0.1%, 0.5%, 1.0%, or 1.5% ascorbic acid (n=10). Vertebrae and muscle color (L(*)a(*)b(*)) were evaluated initially and after 24 h in 80% O(2)/20% CO(2). Vertebrae treated with 0%, 0.05%, or 0.1% ascorbic acid significantly discolored while the longissimus maintained a bright-red appearance. Ascorbic acid treatments 0.5%, 1.0%, and 1.5% significantly minimized vertebrae discoloration and neither induced nor prevented longissimus discoloration. In experiment 2, lumbar vertebrae were treated with 0%, 0.05%, 1.5%, or 2.5% ascorbic acid (n=15), packaged in 80% O(2)/20% CO(2), and displayed for five days (1 °C). Visual color was evaluated daily by a trained panel. Ascorbic acid treatment at 1.5% or 2.5% minimized lumbar vertebrae surface discoloration. Through a five-day display at 1 °C, lumbar vertebrae with 2.5% ascorbic acid had the least bone discoloration.

Thermal and rheological properties and textural attributes of reduced-fat turkey batters.

Currently, modified potato and tapioca starches are used as functional additives in formulating reduced- and low-fat frankfurters. However, cornstarches may serve as alternative sources for comminuted meat systems. Meat batters formulated with ground turkey, 2% sodium chloride, 25% distilled-deionized water (ice), and 4% starch, including acid-thinned dent corn (ATDC), cross-linked waxy maize (XLWM), cross-linked dent corn (XLDC), modified potato (MP), acid-thinned dent corn with xanthan gum (ATDCG), or modified tapioca (MT) were compared. Thermal and structural properties of the batters were evaluated using differential scanning calorimetry (DSC) and dynamic rheological testing. Cooking loss, reheating loss, and texture profile analysis (TPA) were determined for cooked turkey batters. The DSC peak temperatures ranged from 57.5 to 74.9 C, which correlated positively to onset temperatures of the storage moduli (G') for XLWM starch. Incorporation of XLWM, XLDC, MT, or MP starch into turkey batters resulted in significant reductions in cooking and reheating losses. The TPA results showed that 9.42, 8.57, and 8.48 kg of force were required for 75% compression of cooked batter segments containing MP, XLDC, and XLWM starches, respectively. Segments prepared with ATDCG starch were the least firm and most springy of all starch-containing segments.

Comparison between irradiated and thermally pasteurized liquid egg white on functional, physical, and microbiological properties.

A comparative study was undertaken to determine the effect of irradiation and thermal pasteurization on the functional, physical, and microbiological properties of liquid egg white (LEW). The LEW was irradiated or thermally pasteurized then stored at 4 C for 3 mo. Both treatments destroyed the inoculum, Salmonella typhimurium. The microbial growth rate was slower in the irradiated LEW than in the thermally pasteurized treatment. Irradiated samples had 47% lower foam drainage and more stable viscosity than samples that were thermally pasteurized. Volume of angel food cake prepared with irradiated or pasteurized LEW decreased 48 and 57%, respectively, after 90 d. Color did not differ between treatments. Ionizing radiation is an alternative processing method that inhibits microbial growth and helps maintain functionality of LEW.

Tempeh: a mold-modified indigenous fermented food made from soybeans and/or cereal grains.

A variety of indigenous fermented foods exist today; however, tempeh has been one of the most widely accepted and researched mold-modified fermented products. Tempeh is a traditional fermented food made from soaked and cooked soybeans inoculated with a mold, usually of the genus Rhizopus. After fermentation has occurred, the soybeans are bound together into a compact cake by dense cottony mycelium. An important function of the mold in the fermentation process is the synthesis of enzymes, which hydrolyze soybean constituents and contribute to the development of a desirable texture, flavor, and aroma of the product. Enzymatic hydrolysis also may decrease or eliminate antinutritional constituents; consequently, the nutritional quality of the fermented product may be improved. Current technology and new scientific advancements have enabled researchers to examine specific strains of Rhizopus and new substrates such as cereal grains. Because Kansas produces numerous cereal grains, production of a fermented tempeh-like product using wheat, sorghum (milo), oats, rye, barley, corn, and triticale is a definite possibility for generating a Kansas Value-Added Product. In this study, several different tempeh-like products were produced using various cereal grains inoculated with Rhizopus oligosporus NRRL 2549 or R. oligosporus NRRL 2710. Grains used included hard red winter wheat, triticale, yellow sorghum (milo), and red sorghum (milo). The grain source as well as the strain of R. oligosporus used influenced the product's appearance, flavor, and patty integrity. Results showed that R. oligosporus NRRL 2549 produced more mycelium at a more rapid rate than did the R. oligosporus NRRL 2710 strain. The combination of red sorghum and R. oligosporus NRRL 2549 yielded a product with good patty texture, aroma, and appearance. Furthermore, the red sorghum fermented product was well suited for slicing. On the other hand, yellow sorghum inoculated with either R. oligosporus NRRL 2549 or R. oligosporus NRRL 2710 failed to produce an organoleptically suitable product. Triticale also was found to be an unacceptable substrate for the production of a tempeh-like product. Although the fermented wheat product had a desirable aroma and flavor, it lacked patty integrity and crumbled when sliced. Further research is needed to evaluate the economic significance and industrial applications of these tempeh-like products.