Authors:A. Piga, B. Mincione, A. Runcio, I. Pinna, M. Agabbio, and M. Poiana
Olive fruit dehydration is always done locally in non-industrial ovens. This technology poses concern about the quality and safety of the end product. Most of the problems involved in this empirical technology may be solved by a proper control of process parameters. Olive fruits of fourteen Italian cultivars underwent hot air dehydration in mild conditions in a tangential airflow cabinet dryer. At the start, at regular intervals and at the end of the process, sampling was performed to calculate dehydration curves and quality loss. Pre-treatments such as blanching in hot brine, piercing of the skin and salting after blanching were applied. The drying kinetic is strongly affected by pre-treatments and olive characteristics: fruit size, flesh to pit ratio, dry matter. Results showed that mild drying temperature led to slow drying kinetics, even if pre-treatments reduced drying timeto a certain extent. Blanched olives showed, in general, the highest polyphenols content. The fastest drying was measured in the pierced olives, but the best taste was achieved for the salted product.
Authors:R. Ágoston, Cs. Mohácsi-Farkas, and S. Pillai
The food industry utilizes a variety of stressors such as heat treatment to inactivate or prevent the multiplication of
in foods. The aim of this study was to identify the extent to which pre-exposure to sub-lethal temperatures would induce temperature tolerance to 60 °C and result in increased D values.The D value of an avirulent
strain (4ab No 10) was initially determined in Tryptic Soy Broth at 55 °C, 60 °C and 65 °C. The cells were pre-exposed to sub-lethal heat stress of 46 °C (for 30 and 60 min), 48 °C (for 30 and 60 min) and 50 °C (for 30 and 60 min). Then they were exposed to 60 °C and the D
values were calculated. The pre-treatment at sub-lethal temperatures enhanced the D
value of the strain from 3.03 min to longer times. The D
values increased as a function of pre-treatment time at 46 °C: after 30 min exposure it was 5.24 min, and 16.18 min after exposure to 60 min. Similarly, the D
value after 30 min and 60 min exposure at 48 °C was 6.72 min and 14.83 min, respectively. The D
value after 30 min and 60 min exposure at 50 °C, was 13.88 min and 11.16 min, respectively. Heat injury was found to occur in this
strain under the experimental conditions.
Preservative qualities of caraway, known from ancient times, have regained importance as 21st century food safety issues predominate. Essential oil content and its composition of annual caraway varies significantly when row spacing and nutrient supply are manipulated under experimental conditions. During 2006–2007, Carum carvi var. annua cultivar ‘SZK-1’ was sown in small plots in three replications with two factors in split plot design. The row spacings were 24 cm, 36 cm, and 48 cm, and six nutrient application rates were applied (Control, N0K80, N80K0, N80K80, N80+70K0, N80+70K80). The results show that the percentage of essential oil content is influenced by the row space. Furthermore, our data show that increased potassium level enhances the amount of d-carvone in the oil. Every treatment of potassium produced higher d-carvone levels (53.34%) than those found in the control. In 2006, the first year of the two-year study, the highest carvone level (66.25%) was measured in the treatment of N80+70K80, whereas in 2007 the highest level occurred in the N80K80 (49.216%) treatment.
Authors:M. G. Córdoba, J. J. Córdoba, and R. Jordano
In the commercial processing of croquettes a 80 °C heat treatment for 30 min is applied to the raw materials to make a semi-solid paste called „bechamel”. Since the heat treatment is not that of sterilization, some micro-organisms surviving it may proliferate in the next steps, which could introduce two microbial hazards; the presence of pathogenic bacteria and croquettes spoilage. To evaluate microbiological hazards, microbiological analysis of the bechamel cooled and stored under refrigeration following commercial processing were developed at different times of cooling. In addition a fast cooling method was assayed. Immediately after heat treatment used to obtain the bechamel, microbial counts were always under 1 log CFU g-1, except for mesophilic aerobes which were at least of 1.2 log CFU g-1. During cooling used in commercial process of croquettes, levels of most micro-organisms investigated showed high increases as compared with behamel after cooking. In this step mesophilic organisms, psychotropic organisms and yeast reached levels of around 6 log CFU g-1. Enterococci counts increased during cool storage, although always were at levels below 3.2 log CFU g-1.EnterobacteriaceaeandClostridiumsp. only slightly increased at the end of cold storage reaching levels of around 3 log CFU g-1. Although rates which could be considered as being inadmissible were reached at day 5, the use of over 1-day old bechamel could be associated with microbiological sanitary hazards or with the spoilage of the croquettes made afterwards. In contrast, the bechamel cooled at -20 °C air temperature for 12 h, only showed total aerobic counts of under 1 log CFU g-1. Cooling of bechamel is a decisive critical control point and a fast cooling should be considered in the implementation of an HACCP program in the prepared and frozen croquettes process.
Authors:É. Sárdi, É. Stefanovits-Bányai, I. Kocsis, M. Takács-Hájos, H. Fébel, and A. Blázovics
Of the twenty table beet (
ALEF.) cultivars investigated for several nutritionally important components (betaine, betanin, phenol, glucose, fructose, sucrose) formerly (Hájos
et al., 2004), cultivar Ditroit having average quality parameters was chosen for in vitro animal experiments. The hyperlipidemic rat model is suitable to study the physiological effect of table beet on the metabolic alterations and the redox homeostasis in the liver. In fatty liver, as a consequence of hyperlipidemy, the redox homeostasis is strongly injured. General biologically active compounds of table beet have indirect lipid lowering effect and antioxidant properties. Therefore, the effect of lyophilised table beet powder was studied on altered lipid metabolism and redox parameters in hyperlipidemic rats. Hyperlipidemy was induced by a fat-rich diet, and both in the control group and in the hyperlipidemic group, animals were treated with the lyophilised table beet powder (2 g bwkg
) added into rat chow for 10 days parallel with the feeding. Significant antioxidant activity of table beet was recorded in the hyperlipidemic liver. This phenomenon was expected because of the significant amount of betanin and the high total polyphenol content of the beet. Significant beneficial changes were also observed in the serum cholesterol level, alkaline phosphatase and alanine-aminotransferase activities, although a non-expected elevation was observed in the serum bilirubin level in hyperlipidemy. Non-specific H-donor activity was not changed, but protein related free SH-group concentration was decreased in the plasma. Serum triglyceride level was better after table beet treatment in normolipidemy, only. Change of redox-homeostasis was more favourable in the liver during the treatment. Diene conjugate content and the level of induced free radicals decreased during the table beet treatment in case of fatty liver. These changes were due to the bioactive components of the commercially available table beet. Consequently, table beet due to its specific qualities beneficially influences several metabolic pathways, therefore it can be considered as a functional food.
According to the European Union Water Framework Directive, the Hungarian River Basin Management Plan considers as the base of its objectives - which are to assure sustainable water use - to determine the amount of sustainably exploitable water. This study outlines the core properties of current water supply system in Hungary; the distribution of extracted water between different types of sources, where and what kind of water-treatment procedures are needed etc. and also examines the changes in these indicators. This kind of data may contribute to the development of both ecologically and economically sustainable water supply systems.
Prolamin content of buckwheat flour and processed foods was 24.2–42.1 mg/kg dry material measured by ELISA. According to in vitro results buckwheat is suitable for use in coeliac diet, although it contains some antinutritive materials, protease inhibitors and tannin. The allergenic properties of buckwheat are poorly understood. In our investigation intensity of the 24 kD protein band of buckwheat, of which allergenic activity is known has decreased, and 30–35 kD protein associations have been formed after heat treatment. Immunochemical reaction of buckwheat proteins were studied with blood specimens of coeliac and healthy persons.
The main aim of the current paper is to investigate the cyclic behavior of bracing type pure aluminum shear panels (BTPASPs) obtained through a heat treatment of the base material and stiffened by means of welded ribs. The use of the heat-treated aluminum alloy AW1050 A H24 allows to achieve a good hysteretic behavior, while the choice of equipping the plates with ribs is due to the will of shifting buckling phenomena to the plastic field. In order to examine the performances of such a device, experimental tests on two diagonally loaded bracing type pure aluminum shear panels are presented.
Authors:Stefan Varga, Silvia Patachia, and Rodica Ion
Poly (vinyl alcohol) (PVA) is a biocompatible and non-toxic polymer able to form a hydrogel network suitable for drug encapsulation and delivery. A directional controlled release device for porphyrins used in cancer therapy has been devised and implemented based on the swelling and collapse capability of the PVA-based hydrogel. An improved version of this device, having a multi-laminar design with a retarder membrane, is accomplished. The devices can function as model systems for the advanced engineering of transdermal drug-delivery devices for various therapeutic applications (photodynamic therapy, viral inactivation and treatment of psoriasis).