USING CAPACITIVE (RADIO FREQUENCY) DIELECTRIC HEATING IN FOOD PROCESSING AND PRESERVATION – A REVIEW

Capacitive (Radio Frequency) dielectric heating has great potential for achieving rapid and uniform heating patterns in foods, providing safe, high quality food products. This review describes and discusses the major technology behind capacitive (RF) dielectric heating in food processing and preservation, the current applications of the technology in the industry, the potential use of mathematical modeling for heating system design, and the major challenges facing the use of this technology in food processing. A vast amount of work is still necessary to further understand the dielectric properties of both food and packaging materials in order to refine system design and maximize performance of this technology in the field of packaged food products. Various economic studies will also play an important role in understanding the overall cost and viability of commercial application of this technology in food processing.     

Non-substituted fused bis-tetracene based thin-film transistor with self-assembled monolayer hybrid dielectrics

Polycyclic aromatic hydrocarbons with zigzag peripheries are high perspective candidates for organic electronics. However, large fused acenes are still poorly studied due to the tedious synthesis. Herein we report a non-substituted fused bistetracene DBATT (2.3,8.9-dibenzanthanthrene) as the semiconductor on low-voltage-driven organic thin-film transistors. The systematic studies of thin-film growth on various self-assembled monolayer (SAM) modified gate dielectrics and the electrical performances were carried out. The sub-monolayer of the semiconductor film shows larger island domains on the alkyl chain SAM. This device exhibits the hole mobility of 0.011 cm²·V⁻¹·s⁻¹ with a current ratio of I_on/I_off above 10⁵.     

A Capillary GC Determination of Cyclopropenoid Fatty Acids in Cottonseed Oils

A capillary gas chromatography (GC) method was studied for direct analysis for cyclopropenoid fatty acids (CPEFAs) as methyl esters. No thermal alterations were indicated in CPEFA methyl esters on a Supelcowax 10 or a DB-5 capillary column like other fatty acid methyl esters (FAMES), which obviated a second derivatization. GC conditions are described for a complete separation and quantitation of CPEFAs in cottonseed oils. CPEFAs of cottonseed oils from various refining steps were analyzed by the method. The reliability of the method was demonstrated with over 95% recoveries of CPEFA methyl esters diluted in corn oil FAMES at various levels as low as 0.017%.     

NEURAL NETWORK WITH PRINCIPAL COMPONENT ANALYSIS FOR POULTRY CARCASS CLASSIFICATION

This paper reports the results of applying principal component analyses (PCA) of spectral reflectance data to reduce the number of input nodes for neural networks for classification of wholesome and unwholesome poultry carcasses. The results showed that the models with PCA pretreatment of input data performed better than those models without pretreatment. When sensing moving poultry carcasses in an environment without room light with a visible/near-infrared spectrophotometer, the neural network classification models with PCA pretreatment achieved 100% accuracies for training, validating, and testing. For carcasses moving at 60 birds/min, 50 factors were required for perfect classification, while for 90 birds/min 30 factors were required. When sensing in room light, the best model was generated with 30 factors for a shackle speed of 60 birds/min, with a test set accuracy of 95.8%. For 90 birds/min, the best model with a test set accuracy of 96.8% was obtained when 15 factors were used. This study showed that PCA reduced the number of input nodes to the neural network classifiers and, in most cases, improved the model's classification accuracy. It also required fewer training samples and reduced training time.     

Evaluation of epoxy underfill materials for solder flip-chip technology

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Comparison of Four Procedures of Cheese Meltability Evaluation

Two traditional cheese meltability tests, the Schreiber and Arnott, as well as two microwave modifications thereof were compared on a variety of mild and sharp cheddar, process American, and mozzarella cheeses and various process cheese products. There was a marked lack of correlation between the Schreiber and Arnott results indicating that at least two material properties control meltability. The effects of variations in heating time and oven temperature in the nonmicrowave tests and heating time in the microwave tests were determined. Differential scanning calorimetry did not reveal differences useful in predicting melting behavior.     

Effect of Breed, Sex and Tissues on Concentrations of Macrominerals in Goat Meat

Macromineral concentrations in liver, Longissimus dorsi (LD) and Biceps femoris (BF) muscles of doelings and bucks from 2 breeds of goat were determined to study effects of breed, sex, tissue and their interactions on the levels of P, S, K, Ca, Mg and Na in caprine meat. Effects of breed and sex were minimal, but breed x sex interaction had significant influence on levels of K and Mg. Tissue effect was most prominant except for S content. Liver had significantly greater P, Ca and Na contents than skeletal muscles, whereas the former had slightly lower S and significantly lower K and Mg than the latter. Correlations among the levels of the minerals for the liver were different from those for the skeletal muscles.