The Effects of Marination and Cooking Regimes on the Waterbinding Properties and Tenderness of Beef and Bison Top Round Roasts

ABSTRACT: The combined effect of marination and different cooking regimes on the cooking yield and palat-ability of bison and beef top round roasts was investigated. Semimembranosus (SM) muscles from beef and bison top rounds were injected with a marinade to achieve 20% extension by weight and 0.5% sodium chloride and 0.3% sodium tripolyphosphate levels and then subdivided into 4 roasts and cooked by following 4 cooking regimes: cooking at a constant temperature of 75°C (control; C); similar to the control treatment except that roasts were held at an internal temperature of 55°C for 45 min (Hold45) or 90 min (Hold90) prior to final cooking at 75°C; initial cooking at 55°C with a 5°C increase in oven temperature every hour (Step-up) until the 71°C internal temperature was achieved. Cooking yield, expressible moisture, purge, and shear force of processed roasts were determined. Marination by injection improved the yield and tenderness of beef and bison SM roasts. The cooking yield for injected samples (78%) was significantly (P < 0.05) higher compared with noninjected controls (68%). Injected SM roasts from bison had lower cooking losses than those from beef, whereas control samples from these 2 species did not differ in their cooking yields. Injected beef SM was more tender than bison SM; however, marination significantly reduced the shear force values of SM roasts for both species (i.e., shear force values of 82 N in control samples was reduced to 63 N in injected ones). The cooking regimes, Hold45, Hold90, and Step-up (which allowed a longer time at 55 to 60°C), gave products with lower ( P < 0.05) shear force values than those of the controls. Based on the cooking yield and time involved, the Hold 45 treatment performed the best.     

Algae in food: a general review

Abstract

Algae are common all over the Earth. Due to their rich chemical composition and content of bioactive substances they have been used in many fields of industry. Their gelling, thickening and stabilizing properties have led to the development of such products as agar, alginate and carrageenan. Moreover, algae are used in the food industry as food supplements and an addition to functional food. Algae are also added to meat products, such as pasty, steaks, frankfurters and sausages, as well as to fish, fish products, and oils, to improve their quality. Cereal-based products, such as pasta, flour and bread, are another group of products enriched with algae. Due to their properties algae may also be used for construction of fermented functional food. Fermented products containing algae are, most of all, dairy products, such as cheese, cream, milk deserts, yoghurt, cottage cheese, and processed cheese. Combination of fermented products offering a high content of lactic acid bacteria with algae possessing biologically active metabolites of natural origin allows not only to compose products with a high content of nutrients, but also to create a brand new segment of fermented food.     

Effect of blade tenderization and tumbling time on the processing characteristics and tenderness of injected cooked roast beef

The combined effect of blade tenderization (T, NT) and tumbling time (0, 2, 16 h) on quality characteristics of cooked beef roasts processed with 20 or 40% injection level was investigated. Properties of the beef roasts were determined by measuring processing and textural characteristics (shear force, texture profile analysis). Extended tumbling (to 16 h) favorably affected hydration properties and thermal stability, yielding lower cooking loss and purge and higher WHC for beef roasts. It also decreased shear force and hardness of beef samples by 50–60%, but was unable to increase cohesiveness. Blade tenderization prior to injection generally was found to be beneficial for textural characteristics, tended to improve cook yield, but did not influence other hydration properties. An interaction between tenderization and tumbling was observed for shear force. Blade tenderization decreased shear values by 15–20% for roasts tumbled for 0 or 2 h, but did not improve tenderness with extended tumbling.     

Use of poultry protein isolate as a food ingredient: sensory and color characteristics of low-fat Turkey bologna

The potential of using poultry protein isolate (PPI) as a food ingredient to substitute either soy protein isolate (SPI) or meat protein in turkey bologna was investigated. PPI was prepared from mechanically separated turkey meat using pH-shift technology and the prepared PPI was added to turkey bologna at 2 different concentrations (1.5% and 2% dry weight basis). Product characteristics were compared with those prepared with the addition of 2% SPI, 11% meat protein (control-1), or 13% meat protein (control-2). All the 5 treatments were subjected to sensory analysis to evaluate aroma, appearance, color, flavor, saltiness, juiciness, firmness, and overall acceptability of the turkey bologna samples using 9-point hedonic scales. A turkey bologna control sample with 11% meat protein appeared to be softer compared to other treatments as revealed by texture profile analysis while purge loss during storage in a retail display case was significantly (P < 0.05) higher compared to other treatments. Lightness (L*) value of the products decreased during 4 wk of retail storage. A turkey bologna control sample with 13% meat protein appeared to be darker and more reddish compared to other treatments. Replacing meat protein with protein isolates caused increase in yellowish color of turkey bologna. Sensory analysis concluded that 1.5% PPI and 2% PPI could be used as substitute of SPI or lean meat and the treatments could be improved by increasing saltiness and decreasing firmness. PRACTICAL APPLICATION: The study revealed that with slight modifications in saltiness, turkey bologna can be prepared with the addition of poultry protein isolates as an acceptable substitute for soy protein isolate or meat protein. This will help to avoid usage of nonmeat ingredients (as SPI substitute) and to reduce the cost of production (as meat protein substitute) of low-fat turkey bologna.     

Antimicrobial susceptibilities of Listeria monocytogenes strains isolated from food and food processing environment in Poland

A total of 471 Listeria monocytogenes isolates from different types of food and food-related sources in Poland during 2004-2010 were examined. This number includes 200 isolates from fish, 144 from fresh and frozen vegetables, 43 ready-to-eat products (deli foods, cold cuts), 13 from dairy products, 16 from raw meats, 15 from confectionery products and 40 directly from processing plants. All isolates were subjected to serotyping and lineage assays using PCR, and antimicrobial susceptibility using E-test and a broth microdilution method. Of all isolates, 256 (54.4%), 120 (25.5%), 59 (12.5%), 36 (7.6%) were identified as serotypes 1/2a (or 3a), 1/2c (or 3c), 1/2b (or 3b or 7), and 4b (or 4d or 4e), respectively. A direct correlation between the most common serotypes and three L. monocytogenes lineages was also observed. All L. monocytogenes isolates belonged to lineages I (20.2%) and II (79.8%). All strains were sensitive to ampicillin, amoxicillin, gentamicin, erythromycin, trimethoprim, rifampicin, vancomycin, chloramphenicol and sulfamethoxazol. Two of the L. monocytogenes strains (0.42%) showed phenotypic resistance. One strain was resistant to tetracycline and minocycline due to the presence of tet(M). It did not carry gene int, which may indicate that the tet(M) gene in this strain was not integrated in the transposon Tn916-Tn1545 family. The resistance of the second strain to ciprofloxacin and norfloxacin was attributed to active efflux associated with overexpression of gene lde. Our data indicate the low prevalence of antimicrobial resistance among L. monocytogenes isolates from food and food-related sources in Poland.     

Phase Transitions in Confinements: Controlling Solid to Fluid Transitions of Xenon Atoms in an On‐Surface Network

This study reports on “phase” transitions of Xe condensates in on‐surface confinements induced by temperature changes and local probe excitation. The pores of a metal‐organic network occupied with 1 up to 9 Xe atoms are investigated in their propensity to undergo “condensed solid” to “confined fluid” transitions. Different transition temperatures are identified, which depend on the number of Xe atoms in the condensate and relate to the stability of the Xe clustering in the condensed “phase.” This work reveals the feature‐rich behavior of transitions of confined planar condensates, which provide a showcase toward future “phase‐transition” storage media patterned by self‐assembly. This work is also of fundamental interest as it paves the way to real space investigations of reversible solid to fluid transitions of magic cluster condensates in an array of extremely well‐defined quantum confinements.     

Establishment of In Vitro and In Vivo Anticolorectal Cancer Efficacy of Lithocholic Acid-Based Imidazolium Salts

Imidazolium salts (IMSs) are the subject of many studies showing their anticancer activities. In this research, a series of novel imidazolium salts substituted with lithocholic acid (LCA) and alkyl chains of various lengths (S1–S10) were evaluated against colon cancer cells. A significant reduction in the viability and metabolic activity was obtained in vitro for DLD-1 and HT-29 cell lines when treated with tested salts. The results showed that the activities of tested agents are directly related to the alkyl chain length, where S6–S8 compounds were the most cytotoxic against the DLD-1 line and S4–S10 against HT-29. The research performed on the xenograft model of mice demonstrated a lower tendency of tumor growth in the group receiving compound S6, compared with the group receiving 5-fluorouracil (5-FU). Obtained results indicate the activity of S6 in the induction of apoptosis and necrosis in induced colorectal cancer. LCA-based imidazolium salts may be candidates for chemotherapeutic agents against colorectal cancer.     

Efficiency of phospholipid remodeling via acyl-CoA:lysophospholipid acyltransferases action is modified by acyl-CoAs

This study investigated the impact of different acyl-CoAs on remodeling efficiency of PC and PE via the action of acyl-CoA:lysophospholipid acyltransferases (LPLAT). Microsomal fractions from yeast ΔALE1 mutant transformed with an empty plasmid pYES2 or plasmid carrying AtLPCAT or ALE1 encoding genes were used in the experiments. In the preliminary assays, presence of 18:1-CoA in the reaction mixture increased remodeling efficiency of [¹⁴C]PC integrated with microsomal fraction of yeast overexpressing AtLPCAT compared to assays without exogenous acyl-CoA. In further experiments, the effect of five different acyl-CoAs (16:0-CoA, 18:0-CoA, 18:1-CoA, 18:2-CoA, and 18:3-CoA) on remodeling efficiency of yeast microsomal PC and PE via the action of three LPLATs (yeast SLC1 and ALE1 and Arabidopsis LPCAT2) were tested. It has been shown that acyl-CoAs used in the experiments had different effect on the remodeling intensity of PC and PE via action of the tested acyltransferases. Moreover, each acyl-CoA used had a different effect on the tested acyltransferases. Additionally, the assays with DTNB (inhibitor of the LPLAT backward reaction) showed that remodeling of PC and PE by LPLATs can also occur through reactions other than the backward reaction carried out by these enzymes, and that acyl-CoA present in the reaction mixture affected these processes.