Effects of sporulation media and strain on thermal resistance of Bacillus cereus spores

Spores of Bacillus cereus strains ATCC 7004, ATCC 4342 and ATCC 9818 were produced in four sporulation media (Nutrient Agar supplemented with 1 ppm Mn²⁺, Fortified Nutrient Agar, Angelotti Medium and Milk Agar) and their percentages of sporulation and heat resistance parameters obtained in a wide temperature range were compared. In all conditions studied, high rates of sporulation were obtained. Clear differences among D-values for spores produced in the four media were observed. the medium which yielded the most resistant spores and the magnitude with which the sporulation medium affected D-values was different for each strain. z-Values of the three strains were not influenced by the medium used to obtain spores.     

Viability of microencapsulated Bifidobacterium animalis ssp. lactis BB12 in kefir during refrigerated storage

The viability of free and immobilized cells of Bifidobacterium animalis ssp. lactis BB12 incorporated into kefir was studied for 28 days during refrigerated storage. The immobilized bifidobacteria were added directly to previously prepared kefir. Titratable acidity, pH, ethanol, fat, protein and lactose were evaluated in the kefir with bifidobacteria after the storage. The survival of the free and microencapsulated bifidobacteria was evaluated during the storage period and in simulated gastric juice. The pH of kefirs ranged from 4.3 to 4.6. Encapsulation improved significantly the survival of bifidobacteria during exposure to nisin, during the storage period and in simulated gastric juice.     

Cellulose, Hemicellulose and Lignin Content of Raw and Cooked Processed Vegetables

The NDF, ADF, cellulose, hemicellulose and lignin contents of five frozen vegetables (raw and boiled) and five canned vegetables (two of them fried) have been studied. In general, it was observed that boiling resulted in an increase in the NDF, ADF and cellulose content. There was also a slight increase in hemicellulose values. The lignin contents of most vegetables did not change upon boiling. When the cooking process was frying, a drastic decrease of NDF, ADF, cellulose, and lignin contents occurred, while the amount of hemicellulose changed slightly in the vegetables analyzed.     

Application of two forms of silicon and their impact on the postharvest and the content of bioactive compounds in cucumber (<i>Cucumis sativus</i> L.) fruits

The metabolic activity of the fruits continues even after harvest, which results in the loss of bioactive compounds, a decrease in the quality of the fruits, softening and browning, among other negative effects. The use of certain elements such as silicon can improve postharvest quality, since it is involved in the metabolic, physiological and structural activity of plants, moreover can increase the quality of the fruits. In addition, nanotechnology has had a positive impact on crop yield, nutritional value, fruit quality and can improve antioxidant activity. For these reasons, the use of beneficial elements such as silicon in the form of nanoparticles can be a viable option to improve the characteristics of the fruits. In the present study was evaluated the application of potassium silicate (125, 250 and 500 mg L⁻¹) and SiO₂ nanoparticles (125, 250 and 500 mg L⁻¹) during the development of the crop. The results showed that the application of silicon (potassium silicate and silicon nanoparticles) increased the content of total soluble solids (up to 15.6% higher than control), titratable acidity (up to 38.8% higher than control), vitamin C (up to 78.2% higher than control), phenols (up to 22% higher than control), flavonoids (up to 64.6% higher than control), and antioxidant activity in lipophilic compounds (up to 56.2% higher than control). This study suggests that the use of silicon can be a good option to increase the content of bioactive compounds in cucumber fruits when they are applied during the development of the crop.     

PHYSICAL, CHEMICAL, FLAVOR AND SENSORY CHARACTERISTICS OF TWO SWEET CHERRY VARIETIES GROWN IN 'VALLE DEL JERTE' (SPAIN)

Volatile compounds and physical, chemical and sensory characteristics of two sweet cherry varieties autochthonous from ‘Valle del Jerte’, in the Southwest of Spain, during 1995 and 1996 seasons were investigated. ‘Pico Colorado’ had higher values of lightness, chroma, hue, firmness and Brix/acid ratio than     

Dietary Fiber in Spanish Fruits

The dietary fiber, cellulose, hemicellulose, lignin and pectic substances of 21 fruits have been determined. For some of these fruits several varieties and different degrees of ripeness have been considered. The contents of these compounds ranged between 0.2– 2.75% for dietary fiber, 0.06–1.8% for cellulose, 0.00–0.86% for hemicellulose, 0.06–0.5% for lignin and 0.12–1.28% for pectic substances. In some cases the dietary fiber can be affected by the fruit variety. Plantain increased in dietary fiber, hemicellulose and pectic substances content with increased ripening, while no change in cellulose and a decrease of lignin content were observed.     

Strain mapping accuracy improvement using super‐resolution techniques

Super‐resolution (SR) software‐based techniques aim at generating a final image by combining several noisy frames with lower resolution from the same scene. A comparative study on high‐resolution high‐angle annular dark field images of InAs/GaAs QDs has been carried out in order to evaluate the performance of the SR technique. The obtained SR images present enhanced resolution and higher signal‐to‐noise (SNR) ratio and sharpness regarding the experimental images. In addition, SR is also applied in the field of strain analysis using digital image processing applications such as geometrical phase analysis and peak pairs analysis. The precision of the strain mappings can be improved when SR methodologies are applied to experimental images.     

MULTI-AGENT SYSTEMS FOR DECISION SUPPORT: A CASE STUDY IN THE TRANSPORTATION MANAGEMENT DOMAIN

This article describes how agent and knowledge technology can be used to build advanced software systems that support operational decision making in complex domains. In particular, we present an abstract architecture and design guidelines for agent-based decision support systems. We illustrate our approach with a case study in the transportation management domain.     

EFFECT OF TIME AND STORAGE CONDITIONS ON MAJOR VOLATILE COMPOUNDS OF ZALEMA WHITE WINE

ABSTRACT

Changes in quality attributes during bottled storage of white wine were studied. Different storage conditions, temperature, bottle position and exposure to light were studied over 1 year and their effects on major volatile compounds were evaluated. Ethyl lactate and diethyl succinate contents increased after 12 months of storage, whereas isoamyl acetate decreased over this period. The analysis of variance revealed that the temperature had a statistically significant effect on most volatile compounds studied. Multivariate statistical techniques (specifically principal component analysis and linear discriminant analysis) confirmed that temperature is the most important factor, so the samples were distributed into two groups according to storage temperature. A rough differentiation among wines according to the length of storage was also obtained using linear discriminant analysis.

PRACTICAL APPLICATIONS

Aroma is one of the main factors contributing to the quality of wines and their acceptance by consumers. However during bottle storage, young white wines lose their fresh and fruity flavor and suffer a browning process. Among other factors, the time it takes a wine to spoil depends on the wine composition and on storage conditions. Knowledge of the bottle storage stability of Zalema young white wines could allows us to predict their shelf life and establish the best commercial storage conditions to retain their organoleptic characteristics for longer periods.