Dose-Dependent Changes of Chemical Attributes in Irradiated Sausages

To determine the effects of irradiation on the chemical attributes of sausages, TBARS values, volatile compounds, gas compounds, and hydrocarbons of vacuum-packaged sausages were analyzed during 60 d of refrigerated storage. A sulfur-containing volatile compound (dimethyl disulfide), a gas compound (methane), and radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane) were mainly detected in irradiated sausages, and the concentrations of the compounds were irradiation dosedependent. Especially methane and a few hydrocarbons were detected only in irradiated sausages and their amounts were dose-dependent. On the other hand, TBARS values, other off-odor volatiles (carbon disulfide, hexanal), and gas compounds (carbon monoxide, carbon dioxide) were found both in irradiated and nonirradiated sausages. Therefore, it is suggested that irradiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane), dimethyl disulfide, and methane can be used as markers for irradiated sausages

Evaluation of Radiation-induced Compounds in Irradiated Raw or Cooked Chicken Meat during Storage

The concentrations of hydrocarbons, 2-alkylcyclobutanones, and sulfur volatiles in irradiated (0, 5 kGy) chicken meats (raw, pre-cooked, and irradiatedcooked) were analyzed after 0 and 6 months of frozen storage (-40°C) under oxygen permeable packaging conditions. Two hydrocarbons [8-heptadecene (C17:1) and 6,9-heptadecadiene (C17:2)], two 2-alkylcyclobutanones [2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB)], and dimethyl disulfide were determined as radiation-induced detection markers in the irradiated raw and cooked chicken meats. Although, irradiated-cooked samples produced less hydrocarbons and 2-alkylcyclobutanones than pre-cooked irradiated ones, the amount of individual hydrocarbons or 2-alkylcyclobutanones was still sufficient enough to detectradiation treatment even after 6 months of storage at -40°C. Among sulfur volatiles, only dimethyl disulfide were found in meat after 6 months of storage indicating it has potential to be used an irradiation detection marker for frozen-stored meats under oxygen permeable packaging conditions

Catalytic Mechanisms of Metmyoglobin on the Oxidation of Lipids in Liposome Model System

The catalytic mechanism of metmyoglobin (metMb) on the development of lipid oxidation in a phospholipid liposome model system was studied. Liposome model system was prepared with metMb solutions (2.0, 1.0, 0.5, and 0.25 mg metMb / mL) containing none, diethylenetriamine pentaacetic acid (DTPA), desferrioxamine (DFO), or ferric chloride and lipid oxidation was determined at 0, 15, 30, 60, and 90 min of incubation at 37 °C. Metmyoglobin catalyzed lipid oxidation in the liposome system, but the rate of lipid oxidation decreased as the concentration of metMb increased. The amount of free ionic iron in the liposome solution increased as the concentration of metMb increased, but the rate of metMb degradation was increased as the concentration of metMb decreased. The released free ionic iron was not involved in the lipid oxidation of model system because ferric iron has no catalytic effect without reducing agents. Both DFO and DTPA showed antioxidant effects, but DFO was more efficient than DTPA because of its multifunctional antioxidant ability as an iron and hematin chelator and an electron donor. The antioxidant activity of DTPA in liposome solution containing 0.25 mg metMb/mL was two times greater than that with 2 mg metMb/mL due to the increased prooxidant activity of DTPA-chelatable compounds. It was concluded that ferrylmyoglobin and DTPA-chelatable hematin generated from the interaction of metMb and LOOH, rather than free ionic iron, were the major catalysts in metMb-induced lipid oxidation in phospholipid liposome model system.</p

The colour of poultry meat: understanding, measuring and maintaining product quality

Colour is a crucial criterion that determines the consumer acceptance of meat products. Consumers can rapidly assess the visual appearance of fresh meat, and colour causes an immediate positive or negative psychological response (Nanke et al., 1998). Consumers know what fresh or processed meat colour should look like and relate the colour to the product quality, safety and storage history (Kropf, 1980; Seideman et al., 1984; Allen et al., 1997, 1998). In case of U.S. beef industry, about 15% of retail beef is discounted in price due to discolouration, which can be estimated to annual revenue losses of 1 billion dollars (Liu et al., 1995; Mancini and Hunt, 2005). Despite no available estimation of economic losses for poultry meat, the cost reduction caused by surface discolouration in poultry meat is likely to be considerable (Kuttappan et al., 2012). This chapter reviews the fundamentals of meat pigments; the colour of fresh, cooked, cured and irradiated poultry meats; the mechanism and prevention of discolouration and methods for colour measurement.This chapter is published as Nam, K. C., Lee, E. J., and Ahn, D. U. (2016). Chap. 14. The colour of poultry meat: understanding, measuring and maintaining product quality in Achieving Sustainable Production of Poultry Meat Volume 1: Safety, quality and sustainability. S. Ricke (Ed). Burleigh Dodds Science Publishing, Cambridge, UK. Posted with permission.</p

Effect of Electron Beam Irradiation and Storage on the Quality Attributes of Sausages with Different Fat Contents

The 2-thiobarbituric acid reactive substances (TBARS) value of sausages was not affected by fat content, but increased after irradiation (5 kGy). Storage for 60 days increased the TBARS of nonirradiated sausages (P < 0.05), but had no effect on irradiated ones. The numbers of volatile compounds and the amounts of total volatiles increased by irradiation in both high-fat (29% fat) and low-fat (16% fat) sausages. Dimethyl sulfide was detected only in irradiated sausages regardless of fat content (P < 0.05), but disappeared after 60 days of storage. Pentane and 1-heptene were detected only in irradiated samples after 60 days of storage. Low-fat sausages had higher L*-value, but had lower a*- and b*-values than high fat sausages. Irradiation and storage had little effects on both the exterior and interior color (L*-, a*-, and b*-values) of sausages. Fat content had no effect on the sensory parameters of sausages regardless irradiation and storage. However, irradiated sausages had significantly stronger off-odor and off-taste than nonirradiated ones regardless of fat contents (P < 0.05). This indicated that fat content in sausages had minimal effects on the quality of irradiated sausages during storage.</p

Dose-Dependent Changes of Chemical Attributes in Irradiated Sausages

To determine the effects of irradiation on the chemical attributes of sausages, TBARS values, volatile compounds, gas compounds, and hydrocarbons of vacuum-packaged sausages were analyzed during 60 d of refrigerated storage. A sulfur-containing volatile compound (dimethyl disulfide), a gas compound (methane), and radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane) were mainly detected in irradiated sausages, and the concentrations of the compounds were irradiation dosedependent. Especially methane and a few hydrocarbons were detected only in irradiated sausages and their amounts were dose-dependent. On the other hand, TBARS values, other off-odor volatiles (carbon disulfide, hexanal), and gas compounds (carbon monoxide, carbon dioxide) were found both in irradiated and nonirradiated sausages. Therefore, it is suggested that irradiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane), dimethyl disulfide, and methane can be used as markers for irradiated sausages.</p

Evaluation of Radiation-induced Compounds in Irradiated Raw or Cooked Chicken Meat during Storage

The concentrations of hydrocarbons, 2-alkylcyclobutanones, and sulfur volatiles in irradiated (0, 5 kGy) chicken meats (raw, pre-cooked, and irradiatedcooked) were analyzed after 0 and 6 months of frozen storage (-40°C) under oxygen permeable packaging conditions. Two hydrocarbons [8-heptadecene (C17:1) and 6,9-heptadecadiene (C17:2)], two 2-alkylcyclobutanones [2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB)], and dimethyl disulfide were determined as radiation-induced detection markers in the irradiated raw and cooked chicken meats. Although, irradiated-cooked samples produced less hydrocarbons and 2-alkylcyclobutanones than pre-cooked irradiated ones, the amount of individual hydrocarbons or 2-alkylcyclobutanones was still sufficient enough to detectradiation treatment even after 6 months of storage at -40°C. Among sulfur volatiles, only dimethyl disulfide were found in meat after 6 months of storage indicating it has potential to be used an irradiation detection marker for frozen-stored meats under oxygen permeable packaging conditions.</p

Plant- and Animal-Based Antioxidants’ Structure, Efficacy, Mechanisms, and Applications: A Review

Antioxidants are compounds that normally prevent lipid and protein oxidation. They play a major role in preventing many adverse conditions in the human body, including inflammation and cancer. Synthetic antioxidants are widely used in the food industry to prevent the production of adverse compounds that harm humans. However, plant- and animal-based antioxidants are more appealing to consumers than synthetic antioxidants. Plant-based antioxidants are mainly phenolic compounds, carotenoids, and vitamins, while animal-based antioxidants are mainly whole protein or the peptides of meat, fish, egg, milk, and plant proteins. Plant-based antioxidants mainly consist of aromatic rings, while animal-based antioxidants mainly consist of amino acids. The phenolic compounds and peptides act differently in preventing oxidation and can be used in the food and pharmaceutical industries. Therefore, compared with animal-based antioxidants, plant-based compounds are more practical in the food industry. Even though plant-based antioxidant compounds are good sources of antioxidants, animal-based peptides (individual peptides) cannot be considered antioxidant compounds to add to food. However, they can be considered an ingredient that will enhance the antioxidant capacity. This review mainly compares plant- and animal-based antioxidants’ structure, efficacy, mechanisms, and applications