Effects of Sodium Chloride Reduction and Polyphosphate Addition on Clostridium Botulinum Toxin Production in Turkey Frankfurters

Mechanically deboned turkey meat emulsions were made with 1.0, 1.5, 2.0, 2.5, or 3.0% salt (NaCl), or with combinations of 1.5% or 2.0% salt with 0.4% sodium tripolyphosphate (TPP), sodium hexametaphosphate (HMP), or sodium acid pyrophosphate (SAPP). Sodium nitrite levels were constant at 150 ppm. Emulsions were inoculated with a mixture of 10 strains of C. botulinum (10³/g) and incubated at 27°C. Increasing NaCl content from 1.0% to 3.0% delayed toxin production by 3 days on the average. Toxin production was detected earlier when TPP was added, HMP had no effect, and SAPP delayed toxin production.     

Enhancement of confocal microscopy images using Mueller-matrix polarimetry

A simplified procedure based on Mueller-matrix polarimetry has recently been reported as a method of retinal image improvement in a confocal ophthalmoscope [J. M. Bueno et al ., J. Opt. Soc. Am. A 24, 1337 (2007)]. Here, we have applied the technique to imaging static samples providing well-defined reflection properties. The method uses a generator of polarization states in the illumination pathway of a confocal scanning laser system. From the calculated four elements of the Mueller matrix of any sample and instrument combination, the best images defined by different metrics were constructed. For samples with specular, diffuse and mixed reflections, the best-constructed images showed an enhancement in both objective and subjective image quality compared to the original images and those obtained from frame averaging. This technique could improve microscopic imaging in many diverse fields, particularly in biomedical imaging.     

A COMPARISON OF THE EFFECTS OF TEMPERATURE,ENZYME SOURCE,AND SEQUENCE OF DIGESTION ON NEUTRAL DETERGENT FIBER1

ABSTRACT A number of methods for determining dietary fiber have been suggested. Thus, ten modifications of the neutral detergent fiber (NDF) procedure were compared using spinach, bread, and parsnips. Use of Bacillus subtilis alpha amylase resulted in lower (p < .01) NDF values than did porcine pancreatic amylase. Amylase obtained from B. subtilis may contain other enzymes such as hemicellulase and cellulase in small amounts. These enzymes would be undesirable since they may remove some of the fiber fraction, hence the reported NDF would be lower. Temperature of incubation, 21°C or 37°C, did not significantly affect fiber values. Samples predigested with amylase had higher (p < .01) fiber values in a high starch food than samples in which amylase incubation occurred after detergent digestion. NDF values may have been higher because starch was less available for enzymatic hydrolysis before the detergent digestion. When amylase was added directly to the detergent solution after refluxing, NDF was not significantly different (p < .05) from that quantified by the official AACC method or most of the other treatments. Implications of these findings are discussed with respect to their significance in practical applications.