AN EXPERT SYSTEM FOR ACADEMIC COUNSELING

In recent years, high enrollment has greatly increased the counseling loads of academic advisors at American colleges and universities. Expert systems can assist academic counselors by solving a relatively easy class of problems which deal with the most encountered cases. In this paper, a prototype expert system, CLASS COUNSELOR, is presented. CLASS COUNSELOR recommends a set of courses after an interactive session with the student. It handles the upper division courses of the undergraduate program in the Department of Electrical Engineering, University of Florida. The program runs on IBM-AT personal computers and compatibles.     

KEEPING QUALITY OF DIFFERENT PACKAGED SALTED ATLANTIC BONITO "LAKERDA"

Quality and shelf life of salted Atlantic bonito (lakerda) packaged in brine, under vacuum and in oil conditions and stored at 4  ±  1C were studied. The sensory scores of lakerda stored in all package types at 4C were 14 weeks, respectively. The microbiological count of the vacuum-packaged lakerda was extended than that lower of other group sample. Overall results of this study showed that 9 weeks of storage of lakerda in brine was the beginning of spoilage, whereas storage of samples in oil and vacuum package delayed onset of spoilage about 2–3 weeks in terms of chemical analysis. Lakerda stored in cold storage as sensory, chemical and microbiological results for brine- and oil-packaged lakerda showed us that week 11 was the beginning of spoilage, and for vacuum-packaged lakerda, week 13 was the beginning of spoilage.

PRACTICAL APPLICATIONS

Raw fish and processed fish product is highly perishable and has a short shelf life. Packing processing is finding increasing use in the food industry because of its relative advantages versus other food processing methods in eliciting minimal changes in the flavor, microbiological and nutritional qualities of the final product. This paper illustrates the changes induced in salted fish by packaging at different types. By using oil- and vacuum-packaged treatment, shelf life of traditional-packaged (in brine) lakerda could be extended at 4C from 9 weeks to 11–13 weeks.     

Milk protein polymorphisms in Holstein cattle†

Milk samples from 203 Holstein cows were phenotyped for genetic variants α_s1‐casein, β‐casein, κ‐casein and β‐lactoglobulin using starch‐gel electrophoresis. All of the four milk protein loci exhibited polymorphism with allele frequencies of 0.862 ± 0.017 for α_s1‐casein B, 0.966 ± 0.0009 for β‐casein A, 0.712 ± 0.0224 for κ‐casein A and 0.567 ± 0.0245 for β‐lactoglobulin B. The mean heterozygosity estimated over all the four milk protein loci was 0.3015. Genetic equilibrium was observed among all of the loci investigated, except κ‐casein. Chi‐squared tests revealed that there was no significant linkage among studied milk protein phenotypes.     

AN ESTEROLYTIC ACTIVITY FROM A WILD EDIBLE MUSHROOM, LYCOPERDON PERLATUM

Lycoperdon perlatum Pers. (Lycoperdaceae, Agaricales, Agaricomycetidae, Agaricomycetes, Basidiomycota, Fungi) was evaluated for its esterolytic potential. Native electrophoresis of the crude extracts showed four bands having Rf values of 0.34, 0.39, 0.52 and 0.59. The esterase showed the highest activity toward a short-chain substrate, p -nitrophenyl acetate. Optimum reaction conditions for L. perlatum crude extract were attained at pH 8.0 and 40C. Esterolytic activity of enzyme extract was stimulated in the presence of Mn^{2 +} , Fe^{2 +} , Ca^{2 +} and Zn^{2 +} in the reaction mixture. The enzyme activity was stimulated by incubation at pH 6.0 but retained 77% of its original activity at its optimum pH after 24 h. Thermal inactivation was displayed after incubation for 20 min at various temperatures above 30C. At 1 mM final concentration, 2-mercaptoethanol, dithiothreitol, ethylenediamine tetraacetic acid and p -methylphenyl sulfonylfluoride inhibited the esterolytic reaction. These results support that the crude L. perlatum extract possesses an esterolytic activity having properties similar to other esterases.

PRACTICAL APPLICATIONS

Esterases catalyzing the cleavage and formation of ester bonds are known α/β-hydrolases (EC 3.1.1.X). Esterases are used for the synthesis of flavor esters for the food industry, modification of triglycerides for fat and oil industry and resolution of racemic mixtures used for the synthesis of fine chemicals for the pharmaceutical industry. Therefore, the search for new enzyme sources is important for the development of new enzymes and applications.     

Geotechnical properties of some organoclays

The engineering characteristics of clay are dependant on its mineral and chemical structure. When the clay soils interacted with water, their volume and shear strength and compressibility properties change gradually. Large amount of decrease in terms of the shear strength of clay soils due to swelling is observed. In order to solve these problems, the stabilization of clay soils using chemical additives is a prevalent subject of research. In view of this, previous research studies have employed surface active surfactants to modify the fundamental properties of soft clays. In this study, surfactant–clay complexes (organoclays) were developed using a raw clay modification with four surfactants and their geotechnical properties were determined in laboratory conditions. Two of the surfactants are cationic (cetyl trimethyl ammonium chloride, denoted as CTAC and quaternised ethoxylated fatty amine, denoted as QEFA) and the others are anionic (linear alkylbenzene sulphonic acid, denoted as LABSA and sodium lauryl ether sulfate, denoted as SLES). The experimental results indicated that the geotechnical properties of organoclays show significant change when compared to those of natural clay. The specific gravities, unconfined compression strengths and maximum dry densities of all organoclays were decreased. Optimum moisture content and swelling pressure values were decreased in cationic surfactant modified clays. However, the optimum moisture content and swelling pressure values of anionic surfactant clays are increased. A direct shear test was performed to determine the shear strength of organoclays. The test results also showed that the internal friction angles of organoclays were increased. Additionally, the change in the hydraulic conductivity was found to be insignificant.     

PHYSICAL CHARACTERISTICS AND ANTIOXIDANT ACTIVITIES OF ORGANIC GRAPES

Studies on antioxidative activities of fruits have focused mainly on grapes, which have been reported to inhibit oxidation of human low‐density lipoprotein (LDL) at a level comparable to wine. With regard to consumer attitude on the health benefits of the product, organic grapes were selected for study. Organic grapes of Vitis vinifera origin var. Semillon, Columbard, Cabernet sauvignon, Merlot, Grenache and Carignan produced under the control of International Nutrition and Agriculture Certification Company in Kemalpasa/Ulucak were studied. The order of grape varieties concerning grape cluster, stem and number (100) values from the highest to the lowest was determined as: Semillon > Merlot > Cabernet sauvignon > Carignan > Columbard > Grenache. Positive correlation was determined between antioxidant activities (AOA) and total phenols (r = 0.845; P = 0.034). The highest AOA were determined in Merlot (86.55%) and Cabernet sauvignon (83.60%) varieties. Considering LDL, low‐density lipoprotein‐diene values for Cabernet sauvignon and Merlot varieties were 82.73 and 65.48%, respectively. The values of low‐density lipoprotein‐malondialdehyde were different, with the highest percentage found for Semillon (80%). The highest value of total phenols was found in Merlot (4,200 mg/L gallic acid equivalents) variety. Evaluating all analyzed parameters, principal component analysis results demonstrated the similarities between Carignan and Grenache, between Merlot and Cabernet sauvignon and between Columbard and Semillon grape varieties.