STORAGE OF RETORT POUCH BEEFSTEAK AND BEEF STEW PACKED UNDER FOUR HEADSPACE LEVELS

Changes in specific physico-chemical and sensory attributes as well as acceptability of beefsteak and beef stew Meal-Ready-to-Eat (MRE) components packed under different headspace levels (10, 20, 30 and 40 cm³) and stored at selected temperatures of 4, 27 and 38C (40, 80 and 100F) were evaluated over a six month period. No significant changes in microbial counts, pH, residual oxygen, color, hardness and oxidation occurred in retort-packed beefsteak or beef stew. Unlike beefsteak, beef stew received acceptable scores by consumers during all six months of analysis. Consumers' lack of familiarity with beefsteak may have negatively influenced product acceptability. Beefsteak and beef stew acceptability and specific attributes, particularly moistness and firmness, were detrimentally affected by high storage temperatures. Headspace may be increased to 40 cm³ without significant detrimental effects on product quality and acceptability of beefsteak or beef stew.     

A COMPARISON OF PROCEDURES FOR MEASUREMENT OF PIGMENT CONCENTRATION IN PORK

Pigment concentration of pork with known quality defects was evaluated using different methods. In Experiment 1, protein denaturation (induced by postmortem incubation at 5-35C) did not affect the pigment values. However, all methods yielded different absolute pigment values. When using the various procedures on a myoglobin standard, the alkaline haematin method and haematin-chloride method yielded similar results. In Experiment 2, loin samples identified as either PSE (Pale Soft Exudative), RSE (Red Soft Exudative), RFN (Red Firm Non-exudative) and DFD (Dark Firm Dry) based upon drip losses, L-values and ultimate pH, were analyzed for pigment concentration. The methods yielded different absolute pigment values. Moreover, depending on the method, the pigment concentration of meat from these four quality groups was either similar or significantly different. It is concluded that the lower pigment concentration reported for PSE pork may be due to the method used.     

A high-temperature solid-state potentiometric sensor for nitrogen based on ceramic LaAl12O18N

The nitrogen-sensing properties of LaAl12O18N are described for the first time. Positive e.m.f. measurements at high temperature across the cells -Nb (N), -Nb2N, -Al2O3, LaAl12O18NLaAl11O18 (or LaAl12O18N)LaAl12O18N, -Al2O3, -Nb2N, -Nb4N3, were in agreement with PN2(-Nb2N, -Nb4N3)>PN2(-Nb(N), -Nb2N) for the idealized stoichiometric cell reaction -Nb4N3+2-Nb(N)3-Nb2N, thus demonstrating the nitrogen-sensing property of these cells. The e.m.f. for a variety of cells with electrodes containing -V2N, -Nb2N, -Ta2N and Ti2N, were consistent with the predicted equilibrium nitrogen partial pressures.     

Processing Corn Distillers' Grains to Improve Flavor: Storage Stability in Corn-Soy-Milk Blends

Fermentation flavors of corn distillers’ grains (CDG) were removed more completely by extraction with hexane:ethanol (82:18 v/v) azeotrope (HEA) than with hexane (H). Desolventizing included air drying followed by heating to 101°C for 10 min with agitated steam injection. Enriched corn-soy-milk (CSM) blends were formulated with up to 10% HEA- or H-extracted CDG. Color was slightly darker in CSM with CDG. Initial flavor of CSM with up to 7.5% HEA-extracted CDG did not differ significantly from standard CSM. After storage at 25° to 49°C, flavor and lipid stability was satisfactory in CSM with up to 7.5% extracted CDG.     

Characterization of a Caffeine-Resistant Mutant of Aspergillus parasiticus: Role of Amino Acid Metabolism

Aspergillus parasiticus BCRI, a caffeine-resistant mutant of A. parasiticus NRRL 2999, produced abundant amounts of aflatoxins (AF) in yeast extract-sucrose broth only when the medium was supplemented with caffeine. However, little AF production occurred in glucose-mineral salts medium (GMS) regardless of the level of caffeine supplementation. Caffeine-dependent AF production was restored if GMS were fortified with peptone or some other source of amino acids. Subsequent studies indicated that this effect could be achieved by supplementing GMS with specific amino acids, particularly proline, alanine, methionine, arginine or asparagine. Restoration of caffeine-dependent AF synthesis did not occur when GMS was supplemented with purine bases or nucleotides. The results indicated that caffeine-dependent AF production in BCRI was dependent on amino acid catabolism.     

SURVEY OF APPLE GROWING, HARVESTING, AND CIDER MANUFACTURING PRACTICES IN WISCONSIN: IMPLICATIONS FOR SAFETY

To evaluate the safety of current apple growing, harvesting and cider manufacturing practices in Wisconsin, cider manufacturers were contacted in a three-phase survey. Results revealed that seasonal, small-scale production was characteristic of the industry. Most cider mills produced less than 5,000 gal/year; only 6% produced more than 20,000 gal/year. Most cider makers used only tree picked apples (86%), inspected apples before washing (94%), washed (93%) and brushed (87%) apples, but only 16% of mills sanitized washed apples. Most mills (92%) sanitized cider making equipment after each use; however, only a few sanitized between custom pressing apples from different customers. Respondents reported that they strived to improve cider safety by pasteurization (43% of all cider), UV light treatment (4%), use of preservatives (30%), and HACCP (17%). For 31% of all cider, however, processors relied solely on refrigeration and/or freezing. These results show that most cider mills practice many steps believed to enhance cider safety, but results also identify procedures that must be addressed to further improve cider safety.     

MANAGING COMPETITION IN CITY SERVICES: THE CASE OF BARCELONA

ABSTRACT: “Clean and safe” strategies are part of urban regeneration in the entrepreneurial city. These strategies are often characterized by privatization and public–private partnerships that enhance investment and create a city space more amenable to tourists and consumers. While such approaches promote increased investment, and differentiate services by district, they raise challenges of competition, cost escalation, and public participation. Barcelona's solid waste management strategy is presented to show the importance of a strong public coordination role when using competition to promote technological innovation and improved quality in city service delivery.