Issues Related to the Use of Blood in Food and Animal Feed

Blood has traditionally been used as a high protein ingredient in both human food and animal feed, with resulting economic, environmental and nutritional benefits. However, potentially serious health and safety issues related to blood consumption, particularly the risk of pathogenic or harmful metabolic materials, the infectivity of prion diseases, and the presence of identified allergens such as bovine serum albumin (BSA), are causing many consumers to shy away from any product containing either animal blood or ingredients derived from animal blood. Thus, despite the significant volumes of blood produced by slaughterhouses, blood is currently underutilized as a food ingredient. This article reviews the use of animal blood as an ingredient in food intended for human consumption or for animal feed and discusses the related consumer concerns.     

Sensitive Monoclonal Antibody-based Sandwich ELISA for the Detection of Porcine Skeletal Muscle in Meat and Feed Products

A monoclonal antibody‐based sandwich enzyme‐linked immunosorbent assay (ELISA) was developed for the sensitive detection of porcine skeletal muscle in raw and heat‐processed meat and feed products. Heat treatment of meat samples up to 132 °C for 2 h did not affect the assay performance. The assay uses a pair of monoclonal antibodies (MAbs 8F10 and 5H9) specific to skeletal muscle troponin I (TnI). MAb 8F10, reacting to mammalian TnI, is the capture antibody and the biotin‐conjugated MAb 5H9, specific to porcine TnI, the detection antibody. The sandwich ELISA is able to detect 0.05% (w/w) of laboratory‐adulterated pork in chicken, 0.1% (w/w) pork in beef mixtures, 0.05% (w/w) pork meal in soy‐based feed, and 1% commercial meat and bone meal (MBM), containing an unknown amount of pork, in soy‐based feed. This new assay provides a rapid and reliable means to detect the contamination of meat and feed products with trace amounts of porcine muscle tissue to ensure product quality and safety.     

TiO2-grafted multi-walled carbon nanotubes for dye-sensitized solar cells

Dye-Sensitized Solar Cells (DSSCs) comprised of TiO2 porous films with multi-walled carbon nanotubes (MWNT) were prepared at low temperature (150 degrees C). MWNT were incorporated to facilitate the fast electron transport resulting from metallic properties of carbon nanotubes. In order to enhance the effect of MWNT incorporation, TiO2-grafted MWNT (TiO2-MWNT) was synthesized which can increase the electron transport rate further due to proximity of TiO2 to MWNT The presence of TiO2 nanoparticles on the surface of MWNT was confirmed by electron microscopy and energy dispersive X-ray spectroscopy. As in the DSSCs prepared through high temperature sintering of photoanodes, the maximum content of MWNT incorporated into TiO2 was limited to 0.01 wt% relative to TiO2. TiO2 photoanodes including TiO2-grafted MWNT (TiO2-MWNT/P25) enhanced the cell efficiencies by ca. 28% and 14%, relative to TiO2 photoanodes without and with MWNT respectively, reaching the efficiency of 5.0%. Electrochemical impedance spectroscopy (EIS) was utilized to examine the effect of incorporation of TiO2 nanoparticles grafted to MWNT on the cell performance.     

Speciation of animal fat: Needs and challenges

The use of pork fat is a concern for Muslims and Jews, who for religious reasons avoid consuming anything that is pig-derived. The use of bovine materials, including beef fat, is prohibited in Hinduism and may also pose a risk of carrying the infectious agent for bovine spongiform encephalopathy. Vegetable oils are sometimes adulterated with animal fat or pork fat with beef fat for economic gain. The development of methods to determine the species origin of fat has therefore become a priority due to the complex and global nature of the food trade, which creates opportunities for the fraudulent use of these animal fats as food ingredients. However, determining the species origin of fats in processed foods or composite blends is an arduous task as the adulterant has a composition that is very similar to that of the original fat or oil. This review examines some of the methods that have been developed for fat speciation, including both fat-based and DNA-based methods, their shortcomings, and the need for additional alternatives. Protein-based methods, specifically immunoassays targeting residual proteins in adipose tissue, that are being explored by researchers as a new tool for fat speciation will also be discussed.     

Spectral properties of Eu-activated yttrium oxysulfide red phosphor

The effects of Eu on the spectral properties of Y₂O₂S have been investigated. The Y₂O₂S:Eu phosphor powders were prepared with a flux fusion method and electrophoretically deposited on an ITO-coated glass substrate to form a thin layer. Both cathodoluminescence and photoluminescence emission spectra of Y₂O₂S:Eu were measured. The highly intense emission lines at 616 and 626 nm are attributed to the transition from ⁵D₀ to ⁷F₂ levels. The color of Y₂O₂S:Eu phosphor varies from orange to red as the Eu concentration increases from Eu/Y=0.025 (molar ratio) to 0.06. The luminescence decay times are shorter than 1.1 ms for Eu concentrations ranging from 0.025 to 0.06 (Eu/Y molar ratio). The luminescent color becomes redder but less bright as the Eu concentration is increased.     

Synthesis of selenopheno[3,2-c]thiophene derivatives and (opto)electrochemical properties of new low bandgap conjugated polymers

Various selenopheno[3,2-c]thiophene (STh) derivatives functionalized by 4-n-butylphenyl, 4-n-pentylphenyl, 4-tert-butylphenyl, and n-octyl were newly synthesized in a concise and efficient way. Electrochemical and optical properties of polymers were examined by cyclic voltammetry and visible-near infrared (Vis-NIR) spectrophotometry. When compared with polymers of thieno[3,4-b]thiophene, poly(selenopheno[3,2-c]thiophene) (PSTh) was more easily oxidized by ca. 0.2 V (higher HOMO). On the other hand, the bandgap of electrochemically prepared PSTh varied with substituents, but showed similar values to those of poly(thieno[3,4-b]thiophene). While the resonance effect of phenyl substituents slightly lowered HOMO, the combination of resonance and inductive effects decreased LUMO more effectively, resulting in the lowest bandgap of 0.91 eV for 4-tert-butylphenyl functionalized PSTh.     

Monoclonal Antibody-Based Sandwich ELISA for Reliable Identification of Imported Pangasius Catfish

ABSTRACT:  Pangasius catfish, primarily tra  (Pangasius hypophthalmus ) and basa ( Pangasius bocourti ), are farm-raised catfish imported from Asia and have become a common substitute for domestic catfish, grouper, and other high-valued fish in restaurant-served dishes in the United States. This article reports on the development of a monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (ELISA) for the identification of cooked Pangasius fish, basa, and tra. The assay uses a pair of monoclonal antibodies (MAbs F7B8 and T7E10) specific to a heat-stable 36-kDa protein present in a saline extraction of the fish muscle; MAb F7B8, which cross-reacts to all fish species, is the capture antibody and the biotin-conjugated MAb T7E10, which is specific to Pangasius fish, is the detection antibody. This sandwich ELISA reliably identified fully cooked basa and tra from more than 70 common finfish, shellfish, land animal species, and other protein materials tested. It can also sensitively detect 0.5% of adulterated basa or 0.1% tra in a mixed crabmeat products with low intra-assay (%CV: 2.59 to 4.14) and inter-assay (%CV: 3.36 to 3.71) variabilities. The new assay provides a rapid and reliable means of distinguishing fish in the Pangasiidae family from other common food fish and nonfish species and will greatly assist efforts to discourage the illegal practice of substituting high-value popular fish species by the cheaper farm-raised imported Pangasius fish at the retail and restaurant levels.     

Competitive enzyme-linked immunosorbent assay for quantitative detection of bovine blood in heat-processed meat and feed

Animal blood is widely used as a functional additive in food and as a protein supplement in animal feed. Effective analytical methods are therefore needed to enforce labeling regulations for product quality control, as well as to address safety concerns. This study developed a monoclonal antibody (MAb)-based competitive enzyme-linked immunosorbent assay (ELISA) for quantitative detection of ruminant (bovine and ovine) blood in heat-processed meat and feedstuff. MAb BblH9 immunoglobulin G1, which recognizes a 12-kDa, thermostable, ruminant blood protein, was used as the detecting agent in the competitive ELISA. The immunoreactivity of MAb Bb1H9 was confirmed in both an indirect noncompetitive ELISA and a competitive ELISA, in which antigens are presented in immobilized form and free form, respectively. The competitive ELISA was optimized, and three spiked samples adulterated at 0 to 10% were tested to determine the detection limits of the optimized assay. Results showed that MAb Bb1H9 is specific to ruminant blood protein, with no cross-reaction with nonblood samples tested. The optimized competitive ELISA quantitatively detected heat-processed bovine blood over the tested range. The detection limit of the assay for bovine blood in beef (P < 0.001), bovine blood in porcine blood (P < 0.01), and bovine blood meal in soybean meal (P < 0.01) was found to be 0.5% in all cases. This MAb-based competitive ELISA is thus suitable for the sensitive and quantitative detection of ruminant blood proteins in heat processed meat and feed products.     

Quantitative Detection of Poultry in Cooked Meat Products

ABSTRACT: There is a growing awareness of perceived harm from meat species adulteration, both intentional and accidental. The present study developed a monoclonal antibody (Mab)-based enzyme-linked immunosorbent assay (ELISA) for the quantitative detection of chicken and turkey meat adulterated in cooked (100 °C, 15 min) mammalian meat. The specificity of Mab 5D2 to different species (pork, beef, lamb, deer, horse, duck, chicken, and turkey) and tissues (serum, gizzard, heart, and liver) was studied by noncompetitive ELISA. The detection of cooked chicken in beef, and turkey in pork was accomplished by competitive and noncompetitive ELISAs. Both ELISAs were optimized to quantify cooked poultry in red meats. The new Mab-based ELISAs enabled the detection of cooked poultry in red meats at levels as low as 1% (v/v) or better. The correlation ( r > 0.994) between chicken or turkey concentrations and ELISA signals permitted the quantification of poultry adulterants in cooked non-poultry meats.     

Characterization of a 12 kDa thermal-stable antigenic protein in bovine blood

We have previously developed an immunoassay based on monoclonal antibody (MAb) Bb1H9 for quantitative detection of ruminant blood in processed food and feedstuffs. The purpose of this study was to characterize the unknown 12 kDa thermal-stable ruminant-specific antigenic protein recognized by MAb Bb1H9 in order to better define the application scope of the developed assay. Extracts obtained from raw and heat-treated bovine blood-derived products were analyzed with indirect ELISA and Western blot. Target proteins resolved by 2D electrophoresis were subjected to N-terminal sequencing. Results indicated that the 12 kDa protein is a monomer of the tetrameric hemoglobin molecule (64.5 kDa) and that the heme group is not required for its binding with MAb Bb1H9. This MAb can be utilized as a probe for red blood cell derived products of ruminant origin in raw or processed food and feedstuffs to enforce labeling regulations and to address consumer concerns. PRACTICAL APPLICATION: MAb Bb1H9 represents the first antibody with the capacity to recognize bovine hemoglobin both in the absence and presence of the heme group, regardless of the heat treatment. MAb Bb1H9 can therefore be utilized in immunoassays by manufacturers and regulators to detect any ingredients containing hemoglobin or globin (hemoglobin without the heme group) in both raw and processed food and feed materials for product quality control and labeling law enforcement.