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.     

Compiled by THE AMERICAN CERAMIC SOCIETY

The effect of the addition of various oxides on the mullitization of kaolinite was studied by chemical, microscopic, and X-ray methods. A comparative study of the chemical and the X-ray methods of mullite determination has shown that the chemical method (use of hydrofluoric acid) can yield only relative values. The use of X rays appears to give absolute results. The oxides of zinc, lithium, magnesium, iron, manganese, and molybdenum were found to be good mullite builders; sodium, potassium, titanium, and stannic oxides were poor; and boric oxide and calcium oxide were fair accelerators.     

Effect of cerium additive and secondary phase analysis on Ag<Subscript>0.5</Subscript>Bi<Subscript>0.5</Subscript>TiO<Subscript>3</Subscript> ceramics

Cerium-doped silver bismuth titanate—Ag_0.5Bi_0.5TiO₃ (ABT) ceramics have been synthesized by the high-temperature solid-state reaction method. The structure and elemental examination of the prepared ceramic was analysed by X-ray diffraction (XRD), Fourier transform infrared, scanning electron microscopy and energy-dispersive spectroscopy. XRD analysis showed the presence of pyrochlore structure and secondary phase when more than 5 mol% cerium was added. The impact of temperature on cerium-doped silver bismuth titanate samples was analysed by differential thermal analysis and differential scanning calorimetry. Cerium doping caused the flaky morphology comparing with undoped sample. The homogeneity of all the samples was discussed in detail by diffuse reflectance spectrum. This is the first time the reflection process is analysed for the cerium-doped ABT system to the best of our knowledge.     

Edible Methylcellulose-Based Films as Moisture-Impermeable Barriers in Sundae Ice Cream Cones

An edible bilayer film of methylcellulose and palmitic acid, 3:1 w/ w, and a pure methylcellulose film were tested as moisture-impermeable barriers in a simulated sundae ice cream cone. Circular pieces of film were arranged between the sugar cone and the chocolate layer of samples. Sugar cones of samples containing methylcellulose-palmitic acid films showed no detectable moisture increase for 10 weeks at -23°C and for 4 weeks at -12°C and only negligible increments after that. Moisture increase was greater in samples with pure methylcellulose films. Films retarded moisture transfer from ice cream to the sugar cone keeping its crispness longer than 3 months which is the commercial storage-life of the uncoated product.     

LIQUID-LIQUID EQUILIBRIUM OF THE THREE LIQUID PHASES AT EQUILIBRIUM SYSTEM WATER-PHOSFHORIC ACID-DI-ISOPROPYL ETHER AT 25 AND 40°C.

Solubility and liquid-liquid equilibrium data have been obtained for the ternary system Water-Phosproric Acid-Di-isopropyl Ether at 25 and 40^°C. This system presents a three-phase1 region at bcth temperatures. Data for the tie lines end the solubility curve in the zone above the three-phase region at 25^°C have been obtained by analyzing the phcsphcric acid and the di-isopropyl ether composition in the conjugated phases. Di-isoprcpyl ether i"as analyzed by NMR, using acetic acid as internal standard. It was impossible to apply conventional cloud point method to this zone due to the presence of an isooptic region.     

CORRELATION OF COMPLEXATION RATE CONSTANTS OF 1:1 IRON CHELATES WITH LIGAND DISSOCIATION CONSTANTS. FOOD CONSIDERATIONS

Iron which is present as a trace species in foods and drinks is very important to the young infant for normal growth and development. Nutritional status of iron may affect the metabolism of other nutrien***ts. Iron chelates have been shown to have a significant beneficial effect on metal status by increasing metal bioavailability in human diets. From a study of the complexation of iron(III) with a series of structurally similar dicarbonylic ligands in aqueous solution, thermodynamic and kinetic parameters have been obtained. The existence of an essential reaction mechanism throughout the series has been proved. The established correlation suggests that complexation rates of a structurally similar 1:1 chelate of iron(III) may be predicted from the ligand dissociation constant. Thus, an achievable objective might be to develop quantitative scales of ligand ionization degree for predicting expected behavior of complexation reactions. Since the differences observed in the rates of complex formation are not a result of steric effects but of changes in the metal‐ligand electron density, a free‐energy relationship has been obtained for the complexation reactions.     

DEVELOPMENT OF A HYBRID MODEL PREDICTING THE MOUTHFEEL OF YOGURT

Texture perception and mouthfeel are sensory variables that still need further clarification. A reliable method to describe mouthfeel quantitatively by means of physicochemical measurements is missing so far. The current study focuses on a better understanding of the texture perception of yogurt. The final aim of the study consists of the development of a novel hybrid model, which is able to predict mouthfeel sensations objectively. For this purpose, cognitive methods are used in order to merge underlying data pools with respect to process parameters and the composition of dry matter content. These employed data pools result from rheological characterizations as well as sensory analyses of yogurt and from numerical simulations of fluid flow in a simplified anatomical model of the human mouth. This paper introduces the exact procedure of the study. Furthermore, the methods for generating the underlying data pools are described, and the results are presented.

PRACTICAL APPLICATIONS

The in-mouth model is based on fluid mechanics and enables the investigation of human consumption processes that accompany fluid flow in the oral cavity. Here, it reveals mechanical stimuli, which occur because of the movement of the tongue during deglutition. Therewith, the ongoing study affords a new approach to understand factors influencing the popularity and consumer acceptance of several products as their behavior in the mouth can be clarified. Having the software development completed, this innovation represents a great potential for the food industry. While supporting future sensory analyses, it both shortens development cycles of new products and optimizes existing foodstuff.     

USE OF SEMITRAINED PANEL MEMBERS IN THE SENSORY EVALUATION OF HAKE (MERLUCCIUS MERLUCCIUS, L) ANALYZED STATISTICALLY

Abstract The main objective of this study was to evaluate the responses of semitrained sensory assessors to parameters traditionally used in the sensory analysis of hake and to compare their performance with that of trained inspectors. Appropriate statistical methods were used to validate this objective.
The study was carried out with whole gutted hake stored for 7 and 12 days in a controlled atmosphere consisting of 60%/15%/25% (CO₂/O₂/N₂), followed by conventional storage in ice. The hake stored under the CA conditions were preserved better than the control hake at 7 days and at 12 days the difference was even more in favor of the CA storage. Ten parameters evaluated in the sensory tests could be reduced to five with no loss in essential information. The evaluations of the semitrained assessors largely correlated with those of trained inspectors. A model using five parameters and semitrained assessors could be routinely used to evaluate the quality of cooked hake previously stored in ice.     

ISOLATION AND CHARACTERIZATION OF LIMA BEAN (PHASEOLUS LUNATUS) STARCH

Starch from large lima beans (Phaseolus lunatus) was isolated and some of the important characteristics determined. The yield of starch was 22% on a whole seed basis. The shape of the starch granules was round to oval to elliptical, with granules 15–36 μm diameter. Scanning electron micrographs revealed presence of smooth surfaces. Gelatinization temperature range was 70–75–80°C and amylose content was 34.5%. The starch exhibited high single stage swelling and moderate solubility in water. The x-ray diffraction pattern was of the C-type. The viscoamylographic examination on starch paste (6%, w/v) showed the absence of a peak viscosity, a high 95°C viscosity (700 BU) and a breakdown in consistency (60 BU) during the 95°C holding cycle. Scanning electron microscopy showed that native starch granules were very resistant to attack by porcine pancreatic α-amylase. However, defatting slightly increased the extent of hydrolysis. The gel showed poor stability towards refrigerated storage and freeze-thaw cycling. The starch granules were highly resistant to acidic hydrolysis.