Effects of Processing on Aflatoxin Levels and on Mutagenic Potential of Tortillas made from Naturally Contaminated Corn

Naturally contaminated corn containing 127 μ total aflatoxin per kg was divided into kg samples and treated with Ca(OH)2 for making tortillas. The treatments varied in % Ca(OH)2, boiling time, and holding time. Samples were taken after each processing step. Afla-toxin levels and mutagenic activity of acetone extractions of alka-line and reacidified products were measured. All treatments caused a decrease of aflatoxin (up to 46%); however, acidifying products prior to analysis caused reformation of much of the original aflatoxin. All treatments also effected a decrease in the mutagenic potential of the products, except for that of the acidified tortillas which was higher than that of the control corn. The tortilla manufacturing process may not be as effective in aflatoxin destruction as originally surmised.     

Identification of Topical Entities in Discourse: a Connectionist Approach to Attentional Mechanisms in Language

This paper describes a connectionist network which uses surface features and minimal semantic information to identify topic entities within the framework of a simplified representation of the nominal expressions in written narrative discourse. This process is seen as an attentional function critical for interpreting subsequent text and understanding the discourse as a whole. The model also addresses pronoun resolution as a function of attentional state. Since topic entity selection depends heavily on sequentially presented semantic, syntactic and contextual information from the preceding narrative, the model develops an internal representation which incorporates the relevant features of past events in addition to useful features of the current input.     

NUTRITIVE CONTENT OF CANNED TOMATO JUICE AND WHOLE KERNEL CORN

Most of the information on the nutritive value of canned foods in the technical literature was obtained 25–30 years ago. A resurvey of the nutrient content of canned tomato juice and canned whole kernel corn has been carried out on a nation-wide basis with sampling methods directly comparable to the older survey procedures. Although there have been extensive changes in varietal types and processing methods during the past 30 yr the mean nutritional values for these products have changed very little. Comparison of the nutrient values for these products listed in USDA Handbook No. 8 reveals no differences that could not be attributed to seasonal variations. A possible exception is the ascorbic acid content of tomato juice, which for the 1969 season was found to be somewhat lower than the listed value. While sample-to-sample variation is small in terms of the RDA of most nutrients, it can be critical in terms of the regulatory requirements proposed for nutritional labeling. Under this proposal canners would have to grossly "under declare" some nutrients such as ascorbic acid in order to ensure compliance. The indication is that mean values derived from adequate sampling programs are relatively stable although the population may encompass wide ranges of variability. For this reason, nutrient labeling declarations based upon properly constituted average values provide the most practicable solution to the inherent technical problems in the proposed nutritional labeling regulation     

EDUCATIONAL FACILITIES AND FINANCIAL ASSISTANCE FOR GRADUATE STUDENTS IN PSYCHOLOGY: 1967-68.

BASIC INFORMATION IS PRESENTED CONCERNING PSYCHOLOGY GRADUATE PROGRAMS, COSTS, AND FINANCIAL ASSISTANCE AT 221 UNITED STATES AND CANADIAN INSTITUTIONS. A 4-PAGE TABLE INDICATING ADMISSION REQUIREMENTS IS PROVIDED. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequence Analysis of the Candida albicans ADE2 Gene and Physical Separation of the Two Functionally Distinct Domains of the Phosphoribosylaminoimidazole Carboxylase

An ADE2 genomic clone from the pathogenic fungus, Candida albicans, was isolated by complementation of an Escherichia coli purK mutant and the gene was analysed by DNA sequencing. A 1707 bp open reading frame was identified encoding a polypeptide of 569 amino acids with significant homology to all the known yeast ADE2 genes. Sequence homology to both the E. coli purE and purK genes suggests that the C. albicans ADE2 gene is the result of an evolutionary fusion. The amino-acid sequence comparison showed that the N-terminal domain of the Ade2 protein has a 52·5% identity to PurK, whereas the C-terminal domain has a distinct 64·3% identity to PurE. In order to establish the functional relationship of these two regions, deletion mutants of the Ade2 protein were prepared by recombinant expression of the functional domains, which were tested by complementation of their respective E. coli auxotrophs. The sequence described in this paper has been deposited in the EMBL data library under the Accession Number U69606. © 1997 John Wiley & Sons, Ltd.     

EFFECT OF MILK PROTEINS AND STABILIZER ON ICE MILK QUALITY

Ice milk mixes were made with and without stabilizer/emulsifier as well as with and without milk protein isolate (sodium caseinate or whey protein isolate). The mixes were evaluated for rheological, freezing, melting, and sensory properties. Adding a stabilizer/emulsifier blend to ice milk changed its physical properties more than adding milk protein isolates. The mixes with stabilizer/emulsifier exhibited increased viscosity and chewiness and decreased drainage rate, iciness, and vanilla flavor intensity. The mixes with added caseinate exhibited increased viscosity compared with those with added whey protein isolate. Overall, the quality of ice milk mix was more dependent on stabilizer/emulsifier addition than on milk protein isolate addition.     

Maillard Reaction in Glassy Low-Moisture Solids as Affected by Buffer Type and Concentration

This study's objectives were to investigate the effects of buffer type and concentration on the kinetics of the Maillard reaction in low-moisture solids. Glucose loss and brown pigment formation were evaluated in low-moisture glassy systems obtained by lyophilizing solutions containing various concentrations of phosphate or citrate buffer at pH 7 and 25°C. Rate constants for glucose loss decreased as buffer concentration increased, suggesting that a change in the system pH had occurred. Rate constants for browning increased with increasing phosphate buffer concentration and decreased with increasing citrate concentration. Phosphate buffer appeared to catalyze later pathways of the Maillard reaction.     

Water Concentration/Activity and Loss of Vitamins B1 and E in Pork Due to Gamma Radiation

When irradiated, increasing the water content of pork by partial rehydration of freeze-dried L. dorsi muscle resulted in increasing rate of thiamin loss from zero in dry tissue to ca 6%/kGy of irradiation in tissue with 70% water. Conversely, the rate of loss of α-tocopherol decreased, from 44%/kGy at 0% to 32%/kGy at 70% water. Decreasing water activity in buffers or in ground or freeze-dried pork by salt or sucrose had no effect on rate of loss of either vitamin following irradiation. Salt decreased the loss of both vitamins in pork due to competition for the hydroxyl radical by chloride ions.     

EFFECTS OF CONJUGATED LINOLEIC ACID ISOMERS ON SERUM TUMOR NECROSIS FACTOR-A CONCENTRATION IN MICE

In previously studies, we showed that tumor necrosis factor‐α (TNF‐α), a cytokine involved in a variety of biologically important events, is partially involved in the effects of conjugated linoleic acid (CLA). In this report, we further tested the effects of individual CLA isomers on serum TNF‐α concentration along with other biological markers in mice. The animals were fed experimental diets (control, 0.5% CLA‐mixed isomer, 0.25% cis‐9,trans‐11 CLA or 0.25% trans‐10,cis‐12 CLA) for 5 days and were then challenged with endotoxin. Both cis‐9,trans‐11 and trans‐10,cis‐12 CLA isomers reduced serum TNF‐α levels compared to control. CLA had no effect on the other biological markers examined. These results suggest possible early involvement of CLA in immune and/or inflammatory responses, followed by reduction of body fat. Its effect on TNF‐α helps explain in part how CLA modulates other biological functions such as immune response, insulin responses, atherosclerosis and cancer.