COMPARISON OF INVERTASE AND PECTINESTERASE INACTIVATION IN PROCESSED TOMATO PULP1

The heat stability of pectinesterase (PE) and invertase in tomato pulp was investigated to examine the feasibility of using invertase inactivation to predict pectinesterase inactivation. Both invertase and PE were inactivated at 80C in macerated tomato pulp. Between temperatures of 65C to 75C invertase was less heat stable than PE. Results indicate that when temperatures above 80C are reached, almost instantaneously, it would be feasible to use invertase activity as measured by sucrose level to predict PE activity.     

Limonene and Myrcene Sorption into Refillable Polyethylene Terephtalate Bottles, and Washing Effects on Removal of Sorbed Compounds

The sorption of two orange volatile compounds, myrcene and limonene, into refillable polyethylene terephtalate bottles, different types of polyethylene terephtalate strips, and polycarbonate strips, was studied. The bottles were washed with sodium hydroxide solutions and remaining aromas in the plastic were analyzed. Sorption continued during the 12 wks storage, but the major part was sorbed during the first week. Bottles stored at 25°C absorbed considerably more myrcene and limonene than bottles stored at 4°C. A simulated industrial washing procedure removed small amounts of the aromas but 50–80% remained in the packaging material. Polycarbonate absorbed flavors to a much larger extent than did polyethylene terephtalate.     

Physiological Characterization of Common Fungi Associated with Cheese.

A multivariate statistical method (PLS) was used for a physiological characterization of fungi associated with the cheese environment. The combined effects of pH, salt content, oxygen and carbon dioxide levels on growth and sporulation were studied. Significant factors affecting growth were salt content, level of carbon dioxide and temperature. Interactions between those factors were illustrated and showed that some fungi were especially sensitive to carbon dioxide levels and salt content, at low temperature. Sensitivity to the factors often was more pronounced in the early growth phase. Results may aid in eliminating unwanted fungal growth during cheese production.     

On texture formation of nickel electrodeposits

Electrodeposited nickel has been investigated by cross-sectional transmission electron microscopy and X-ray diffraction. The <100> fibre texture and fine-grained, dislocated columnar microstructure has been considered with respect to the mechanisms of growth during electrodeposition. Fine, codeposited nickel oxide hydroxide precipitates which have formed on the {111} planes appear not to have influenced texture formation. Although strong inhibition by adsorbed hydrogen or organic species is suggested from the work of others, this has not resulted in any codeposition of other species, either crystalline or amorphous.     

Non-prejudiced Detection and Characterization of Genetic Modifications

The application of gene technology is becoming widespread much thanks to the rapid increase in technology, resource, and knowledge availability. Consequently, the diversity and number of genetically modified organisms (GMOs) that may find their way into the food chain or the environment, intended or unintended, is rapidly growing. From a safety point of view the ability to detect and characterize in detail any GMO, independent of publicly available information, is fundamental. Pre-release risk assessments of GMOs are required in most jurisdictions and are usually based on application of technologies with limited ability to detect unexpected rearrangements and insertions. We present an array-based approach to address these problems and show with three examples (GTS 40-3-2 Roundup Ready and event A5547-127 soybean as well as T25 Liberty Link Maize) that the method can detect and characterize GMOs with high accuracy while making very few prior assumptions about the actual genetic modifications or constructs in question. Based on the array results, a simple polymerase chain reaction-scheme is also described that will enable the user to characterize the inserted sequences to DNA sequence level. The method may provide the biotechnology developers and risk regulators with a useful tool to improve pre-market risk assessments as well as seed producers and other food chain and environmental stakeholders with a platform to improve their ability to detect and characterize GMOs.     

Potential of anticlostridial Lactobacillus isolated from cheese to prevent blowing defects in semihard cheese

Five anticlostridial Lactobacillus strains isolated from cheese were selected for a mixed adjunct culture. Cheese with the mixed adjunct culture (experimental) and without (control) was made in triplicate and ripened as vacuum‐packed and surface‐ripened cheese. Cheese gross composition was similar. Excessive gas formation occurred only in control cheeses. In contrast to control cheeses, the experimental cheeses were dominated by the added adjunct Lactobacillus strains (repetitive‐PCR). Casein breakdown was not influenced, however, the total amount of amino acids and pH was slightly lower in the experimental cheeses. Anticlostridial nonstarter Lactobacillus strains have potential as protective adjunct cultures against blowing defects in cheese.     

Reduced Stroop Interference for Opponent Colors May Be Due to Input Factors: Evidence From Individual Differences and a Neural Network Simulation.

Sensory or input factors can influence the strength of interference in the classic Stroop color-word task. Specifically, in a single-trial computerized version of the Stroop task, when color-word pairs were incongruent, opponent color pairs (e.g., the word BLUE in yellow) showed reduced Stroop interference compared with nonopponent color pairs (e.g., BLUE in red). In addition, participants' color discrimination ability was measured by standard color vision tests (i.e., Farnsworth-Munsell 100-Hue Test and Ishihara plates). Error rates in the Farnsworth-Munsell test correlated positively with the amount of Stroop interference. Neural network simulations (variants of J. D. Cohen, K. Dunbar, & J. L. McClelland's, 1990, model) showed that only a distributed trichromatic input layer was able to simulate these findings. Thus, sensory input from the color system needs to be incorporated into current accounts of the Stroop effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PREVIOUS BACTERIAL INFECTION AFFECTS TEXTURAL QUALITY PARAMETERS OF HEAT‐TREATED FILLETS FROM RAINBOW TROUT (ONCORHYNCHUS MYKISS)

ABSTRACT

Sensory quality of fish meat is influenced by many parameters prior to slaughter. In the present study, it was examined if previous infections or damages in the muscle tissue influence product quality parameters in fish. Fillets from rainbow trout (Oncorhynchus mykiss) reared in seawater at a commercial fish farm were sensory evaluated for more than a year after recovery following physical tissue damage or infection by the bacterial pathogens Yersinia ruckeri and Vibrio anguillarum. The effect of vaccination was also included as some fish were vaccinated before bacterial challenge. The fish fillets were sensory examined as heat‐treated and cold‐smoked. Heat‐treated fillets from nonvaccinated fish previously infected by V. anguillarum had changed textural characteristics and were less flaky, had a lower oiliness and a higher toughness and fibrousness in comparison with control fish. This article was the first to describe a correlation between previous infections in fish and changes in sensory‐quality parameters.

PRACTICAL APPLICATIONS

This work contributes with knowledge about sensory‐quality parameters of fish meat after recovery from infections and physical‐tissue damage. Because the results demonstrate an influence on the texture from previous disease, the practical potentials of the results are valuable for the aquaculture industry. In order to minimize the effects of previous diseases on the sensory quality regarding the texture, these fishes should be processed as cold‐smoked instead of being sold as raw meat. The established correlation between disease history stresses the importance of disease prevention in aquaculture production, e.g., vaccination of the fish.     

THE EFFECTS OF THERMAL AND NONTHERMAL PROCESSING METHODS ON APPLE CIDER QUALITY AND CONSUMER ACCEPTABILITY

Due to increased concern about the safety of fruit, vegetable and juice products, the FDA has mandated that these must undergo a 5‐log reduction in pathogens. The development of various processing methods for juice products has caused the need to determine the effects of these methods on said products. The effect of thermal pasteurization, UV irradiation and ozone treatment on apple cider quality and consumer acceptability was studied over 21 days. Thermally pasteurized samples were different in color and less preferred in all areas of consumer acceptability. UV‐irradiated samples were lower in soluble solids for the first 7 days and showed no significant difference in consumer acceptability. Ozone‐treated cider had greater sedimentation, lower sucrose content and a decrease in soluble solids by day 21. UV irradiation allows for a more cost‐effective method to produce safe apple cider with minimal quality and consumer acceptability differences.     

Inhomogeneous plastic flow investigated by X-ray absorption microtomography of an aluminium alloy containing marker particles

By combining a synchrotron X‐ray source and the microtomography technique, the displacement gradient tensor components can be measured directly throughout the volume of a metal sample containing highly absorbing marker particles to detect material flow. The present article describes application of these techniques to compression of a rectangular Al–W specimen with a central hole. The results show that the externally imposed axial displacement gradient is accommodated mainly in two 45° shear bands passing through the hole. A simple deformation analysis provides insight into shear band formation.