Effects of Ascorbic Acid and Antioxidants on Color, Lipid Oxidation and Volatiles of Irradiated Ground Beef

Irradiation significantly decreased the redness of ground beef, and the visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had significantly lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During the aerobic storage, the S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol + α-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol + tocopherol in irradiated ground beef was superior to that of ascorbic acid

Antioxidant Properties of Far Infrared-Treated Rice Hull Extract in Irradiated Raw and Cooked Turkey Breast

The antioxidant effect of far-infrared-treated rice hull (FRH) extracts in irradiated turkey breast meat was compared with that of sesamol and rosemary oleoresin. FRH significantly decreased TBARS values and volatile aldehydes (hexanal, pentanal, and propanal) and was effective in reducing the production of dimethyl disulfide responsible for irradiation off-odor in irradiated raw and cooked turkey meat during aerobic storage. The antioxidant activity of FRH (0.1%, w/w) was as effective as that of rosemary oleoresin (0.1%). However, the addition of FRH increased red and yellow color intensities and produced an off-odor characteristic to rice hull in raw and cooked meat, and cannot be used in meat without further refining process to remove off-color and off-odor compounds

Automated Dynamic Headspace/GC-MS Analyses Affects the Repeatability of Volatiles in Irradiated Turkey

The amounts of dimethyl disulfide and dimethyl trisulfide decreased as sample holding time in an autosampler (4 °C) before purge increased, whereas those of aldehdyes increased as holding time increased due to lipid oxidation. Helium flush of sample vials before sample loading on an autosampler retarded lipid oxidation and minimized the changes of sulfur volatiles in raw meat, but was not enough to prevent oxidative changes in cooked meat. Although DH/GC-MS is a powerful method for automatic analysis of volatiles in meat samples, the number of samples that can be loaded in an autosampler at a time should be limited within the range that can permit reasonable repeatabilities for target volatile compounds

Volatile Production of Irradiated Normal, PSE, and DFD Pork

With both aerobic and vacuum packaging, irradiation increased the production of sulfur-containing volatiles in all three pork types (normal, PSE, DFD) at day 0, but did not increase hexanal - the major indicator volatile of lipid oxidation. PSE pork produced the lowest amount of total sulfur-containing volatiles in both aerobically and vacuum-packaged pork at day 0. Majority of sulfurcontaining volatiles produced in meat by irradiation evaporated during the 10-day storage period under aerobic packaging conditions. With vacuum packaging, however, the all the volatiles produced by irradiation remained in the packaging bag during storage. Irradiation had no relationship with lipid oxidation-related volatiles (e.g., hexanal) in both aerobic and vacuum-packaged raw pork. DFD muscle was very stable and resistant to oxidative changes in both irradiated and nonirradiated pork during storage, suggesting that irradiation can significantly increase the use of raw DFD pork and greatly benefit pork industry

Quality Characteristics of Aerobically Packaged and Irradiated Normal, PSE, and DFD Pork

Irradiation and storage increased lipid oxidation of normal and pale-soft-exudative (PSE) muscles, whereas dark-firm-dry (DFD) muscle was very stable and resistant to oxidative changes. Irradiation increased redness regardless of pork-quality type, and the increases were proportional to irradiation dose. Irradiation increased the production of sulfurcontaining volatiles, but not lipid oxidation products. The total volatiles produced in normal and PSE pork were higher than that in the DFD pork. Some volatiles produced in meat by irradiation evaporated during storage under aerobic packaging conditions. Nonirradiated normal and DFD pork had higher odor preference scores than the nonirradiated PSE, but irradiation reduced the preference scores of all three pork-quality types. This suggests that irradiation can significantly increase the use of DFD pork, and can greatly benefit pork and beef industries

Quality Characteristics of Vacuum-Packaged, Irradiated Normal, PSE, and DFD Pork

Irradiation increased the redness of vacuum-packaged pork loins regardless of meat type. Irradiation and storage time had no effect on the 2-thiobarbituric acid reactive substances (TBARS) values of normal, PSE and DFD pork. Irradiation increased the production of sulfur (S)-containing volatile compounds and total volatiles in all three pork types. Normal pork had more values of total and S-containing volatile compounds on irradiation than the PSE and DFD pork. The volatiles produced by irradiation remained in the packaging bag during storage. The odor acceptance of the three meat types was not different, but panelists could distinguish irradiated meat from the nonirradiated. Irradiation and storage of meat in vacuum packaging may be desirable for long-term storage, but may reduce the acceptance of irradiated meat. Double packaging—individual packaging of meat with oxygen permeable film and repackaging multiple individual packages in large vacuum-packaging bags for irradiation and storage—and opening the outside vacuum packaging bag 1–2 days before sale, is recommended to reduce irradiation odor

Factors Affecting Cooked Chicken Meat Flavour: A Review

Flavour, one of the most important factors affecting consumers’ meat-buying behaviour and preferences, comprises mainly of taste and aroma. The cooked meat flavour, that is important from the producer and consumer point of view, is affected by several pre- and post-slaughter factors, including breed, diet, post-mortem ageing, and method of cooking. Moreover, chicken meat is prone to the development of off-flavours through lipid oxidation, which reduce the quality of the chicken meat. The aim of this review is to discuss the main factors affecting cooked chicken meat flavour which helps producers and consumers to produce the most flavoured and consistent product possible. Cooked chicken meat flavour is thermally derived via the Maillard reaction, the degradation of lipids, and interaction between these two reactions. Factors affecting the flavour of cooked chicken meat were identified as breed/strain of the chicken, diet of the bird, presence of free amino acids and nucleotides, irradiation, high pressure treatment, cooking, antioxidants, pH, and ageing

Functional properties of tooth pulp neurons responding to thermal stimulation

ManuscriptThe response properties of tooth pulp neurons that respond to noxious thermal stimulation of the dental pulp have been not well studied. The present study was designed to characterize the response properties of tooth pulp neurons to noxious thermal stimulation of the dental pulp. Experiments were conducted on 25 male ferrets and heat stimulation was applied by a computer-controlled thermode. Only 15% of tooth pulp neurons (n=39) responded to noxious thermal stimulation of tooth. Tooth pulp neurons were found in both the superficial and deep nuclear regions of the subnucleus caudalis (Vc) and in the interface between nucleus caudalis and interpolaris (Vc/Vi). Thirty-seven neurons had cutaneous receptive fields and were classified as either NS (16) or WDR (21) neurons. Repeated heat stimulation of the dental pulp sensitized and increased the number of electrically evoked potentials of tooth pulp neurons. These results provide evidence that both the Vc and Vc/Vi region contain neurons that respond to noxious thermal stimulation of the dental pulp and that these cells may contribute to the sensitization process associated with symptomatic pulpitis

Quality Characteristics of Irradiated Chicken Breast Rolls from Broilers Fed Different Levels of Conjugated Linoleic Acid

Dietary CLA treatment reduced color a*- and b*-values of cooked chicken breast rolls. Sensory panels rated the color of cooked chicken rolls with CLA treatments darker than the control. The production of CO in cooked chicken rolls increased dramatically after irradiation and was correlated with the increased redness of cooked chicken rolls after irradiation. Irradiation greatly increased volatile production and induced a metallic off-flavor in chicken rolls. The hardness of chicken rolls increased and juiciness decreased as the dietary level of CLA increased, and consumer preferred the color of cooked chicken rolls after irradiation to the nonirradiated ones. Although dietary CLA was somewhat positive in reducing pinkness, but negatively influenced to the eating quality of irradiated cooked chicken rolls

Prevention of Pinking, Off-Odor, and Lipid Oxidation in Irradiated Pork Loin Using Double-Packaging

Lipid oxidation, color, volatiles, and sensory evaluation of double-packaged pork loin were determined to establish a modified packaging method that can improve the quality of irradiated pork loins. Vacuum-packaged irradiated samples produced dimethyl sulfide and dimethyl disulfide responsible for irradiation off-odor, whereas lipid oxidation was promoted under aerobic conditions. Exposing doublepackaged irradiated pork to aerobic conditions for 1 to 3 d was effective in controlling both lipid oxidation and irradiation off-odor, regardless of packaging sequence. Sensory panels could distinguish the decrease in irradiation off-odor intensities by modifying packaging method. However, carbon monoxide-heme pigments, responsible for the increased redness by irradiation, were not effectively controlled by double packaging alone