Agar-Gel Immunodiffusion Test for Rapid Identification of Pollock Surimi in Raw Meat Products

A test for the rapid identification of raw pollock surimi (TRIPS) was developed. This was an adaptation of previously developed field screening agar-gel immunodiffusion tests for speciation of meat products. It was specific for Alaska pollock surimi at 2% concentration and other surimis at higher concentrations, showed detectable sensitivity to surimi in meat at 2–4%, and was 100% accurate in detection in laboratory trials.     

Optimal adjustment strategies for a process with run-to-run variation and 0–1 quality loss

As short run manufacturing becomes more prevalent, run-to-run components of variation, such as that contributed by set-up error, have greater potential to crucially affect product quality. While efforts should be made to eliminate such between-run variance contributing factors, some will always be present. Here, we assume there is one such factor which we envisage as set-up error that, unless the process is adjusted, remains fixed throughout a run. We develop a single adjustment strategy based on taking a sample of fixed size from the process. If a significant set-up error is indicated, a single compensatory adjustment, equal to the predicted process offset, is executed. The actual procedure depends on process parameters, including adjustment error, run size, and adjustment and sampling costs. The procedure not only specifies the adjustment amount, if any, but the time during the run at which to adjust. The procedure is, optimal among all fixed sample size procedures for the chosen cost function. Besides incorporating adjustment and sampling costs, the cost function is based on a 0-1 loss criterion, where the loss is 0 (1) units per item produced if the process offset caused by set-up error is less than or equal to (greater than) a specified amount. Tables are provided, with examples, illustrating the procedure for representative values of process parameters, costs, and run sizes.     

A Rapid Method for the Evaluation of Emulsion Stability of Non-Dairy Creamers

A rapid method based on the Lowry protein assay was developed for the determination of the emulsion stability of nondairy creamers in a model system. The method used the detergent and crystallization properties of the anionic surfactant sodium dodecyl sulfate to solubilize the casein present in the creamers. Increasing concentrations of the divalent cations Ca⁺⁺ and Mg⁺⁺ resulted in an increasing degree of emulsion breakdown in a commercial nondairy creamer. Significant differences in the emulsion stability of five commercial nondairy creamers were also demonstrated with this method.     

INCIDENCE OF AFLATOXIGENIC ISOLATES OF ASPERGILLUS FLAVUS/PARASITICUS OBTAINED FROM GEORGIA CORN PROCESSING PLANTS

Two corn processing facilities within Georgia were evaluated in order to determine the incidence of Aspergillus flavus or A. parasiticus within the plant and in corn harvested and processed in 1984 and 1985. Conidia of A. flavus/parasiticus were found in all corn samples evaluated as well as in settled dust samples taken within these processing facilities. Isolates were obtained by using the differential/selective medium Aspergillus flavus/parasiticus agar. Upon subsequent culture only 55% of the selected isolates were confirmed as belonging to A. flavus/parasiticus group. Some of these isolates were randomly chosen and their ability to produce aflatoxins B₁, B₂, G₁, or G₂ evaluated. Thirty-two percent of the A. flavus/parasiticus isolates cultured for aflatoxin production were found to be aflatoxigenic.     

BIOFUMIGANT COMPOUNDS RELEASED BY FIELD PENNYCRESS (<Emphasis Type="Italic">Thlaspi arvense</Emphasis>) SEEDMEAL

Defatted field pennycress (Thlaspi arvense L.) seedmeal was found to completely inhibit seedling germination/emergence when added to a sandy loam soil containing wheat (Triticum aestivum L.) and arugula [Eruca vesicaria (L.) Cav. subsp. sativa (Mill.) Thell.] seeds at levels of 1.0% w/w or higher. Covering the pots with Petri dishes containing the soil-seedmeal mixture decreased germination of both species at the lowest application rate (0.5% w/w), suggesting that the some of the phytotoxins were volatile. CH₂Cl₂, MeOH, and water extracts of the wetted seedmeal were bioassayed against wheat and sicklepod (Senna obtusifolia (L.) H. S. Irwin & Barneby) radicle elongation. Only the CH₂Cl₂ extract was strongly inhibitory to both species. Fractionation of the CH₂Cl₂ extract yielded two major phytotoxins, identified by gas chromatography–mass spectrometry and NMR as 2-propen-1-yl (allyl) isothiocyanate (AITC) and allyl thiocyanate (ATC), which constituted 80.9 and 18.8%, respectively, of the active fraction. When seeds of wheat, arugula and sicklepod were exposed to volatilized AITC and ATC, germination of all three species was completely inhibited by both compounds at concentrations of 5 ppm or less. In field studies, where seedmeal was applied at 0.50, 1.25, and 2.50 kg/m² and tarped with black plastic mulch, all of the treatments significantly reduced dry weight of bioassay plants compared to the tarped control, with the highest seedmeal rate decreasing dry matter to less than 10% of the control 30 d after seedmeal application. Field pennycress seedmeal appears to offer excellent potential as a biofumigant for high-value horticultural crops for both conventional and organic growers.Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Refractories for Copper Production

Abstract

The furnaces used for producing molten copper from concentrates and scrap - flash: smelters, converters, and anode and fire-refining furnaces - present a unique combination of challenges to refractory life. Highly aggressive slags, mechanical stresses, batch operation, and increasingly higher operating temperatures all combine to destroy most refractory materials. Over the past generation, copper producers have adopted refractory materials biased on the MgO-Cr₂O₃ system to meet these challenges, to the point where ‘mag-chrome’ brick is used almost exclusively in the industry. However, recent environmental imperatives have created a need to develop chrome-free alternative refractories for copper smelters, converters and refining furnaces. Some possible alternative materials are introduced, and speculation is made about the locations where they might be used most advantageously.     

FRIENDS AND NEIGHBORS: HOMEOWNERSHIP AND SOCIAL CAPITAL AMONG LOW‐ TO MODERATE‐INCOME FAMILIES

ABSTRACT: This research explores whether homeownership leads to increased individual social capital among low‐ to moderate‐income families. Social capital refers to social resources a person can access through contacts with others in his or her social networks. We theorize that homeownership can motivate interactions with others in one's neighborhood and therefore build social capital. Using a sample of low‐ and moderate‐income homeowners and a matched sample of renters, we collect data on overall social resources and neighborhood‐specific social resources. We find that homeowners have more total social capital resources and more neighborhood social capital resources than renters. Neighborhood group involvement has an indirect effect on social capital, but explains only a small amount of the influence of homeownership. These findings hold when controlling for household‐level and neighborhood‐level sociodemographic variables, as well as when using statistical models that account for endogeneity. Based on this evidence, we conclude that homeownership gives people access to social capital via increased social ties to others. We discuss the implications of this finding for housing policy and suggest new directions for research on social capital.     

CHEMICAL ANALYSIS OF CENTROSEMA PUBESCENCE LEGUME SEEDS

The amino acid and fatty acid compositions of the seeds of the wild Nigerian legume Centrosema pubescence have been determined, along with proximate composition and levels of selected inorganic ions. Total unsaturation of the lipid extract amounted to about 59% with oleic acid being not only the dominant unsaturated fatty acid, but also the overall single dominant fatty acid. The first limiting amino acid was methionine. Lysine was present at a level higher than in the reference egg protein. The proximate composition was characterized by high protein and crude fiber contents (21 and 9.7%, respectively) and by low crude fat (about 2.3%) and ash contents (about 3.5%). Varying levels of selected inorganic ions were also detected .