Papers by Elisabeta Botez
A new probiotic product named ROSALACT was obtained from pasteurized milk with medicinal plants e... more A new probiotic product named ROSALACT was obtained from pasteurized milk with medicinal plants extracts (rosehip extract and liquorice extract) using a mixed culture of probiotic bacteria ABT 5, supplied by Chr. Hansen (Copenhagen, Denmark). The probiotic dairy product ROSALACT followed to combine the beneficial effects of probiotic bacteria with the therapeutic virtues of medicinal herbs. The aim of the present study was to characterize from sensorial and rheological stand point the probiotic product ROSALACT. The novel product was appreciated by the panelists (especially taste, appearance, texture and aftertaste), and rheological measurements show the ROSALACT product is a non-Newtonian fluid, with characteristics independent of time.
The aim of this study was the identification and the analysis of the weight losses, structure, te... more The aim of this study was the identification and the analysis of the weight losses, structure, texture and microbiota changes appeared in thermic treated chicken breast. The experiment was structured as a comparison between the effects of cooking meat using two kinds of heating medium -water and oil. The chicken breast water boiling treatment has been developed at various temperatures and periods 70, 80, 90˚C/5, 10, 15 minutes and the sunflower oil frying process has performed at 100, 105, 110˚C/1, 3, 5 minutes). The technological loses for frying (110˚C/5' were 17.45%) denote that this is more suitable for the chicken breast than the boiling (90˚C/15' were 34.40%) in order to maintain the cellular juice and the nutrient compounds into the product. The meat with the best texture is the boiled one at 80˚C/10 minutes. The microbiota of the thermic treated meat was inactivated under the standards inferior limits or it was absent.
The main purpose of the study was to determine an optimal technological variant for obtaining a n... more The main purpose of the study was to determine an optimal technological variant for obtaining a new product, yoghurt with added walnuts and strawberries jam. Designing the product derived from several considerations: diversification of yoghurts on the Romanian market, adapting the nutrients of yoghurt to the needs of some consumers, by improving milk fat with vegetal fat from walnuts, enriching the yoghurt with antioxidants from strawberry jam. There have been manufactured two variants of product and a blank sample. The analyses regarded physico-chemical properties (total solids, acidity, minerals content, fat content, viscosity), sensorial properties and stability. The obtained data were statistically analysed. All the analysed parameters accomplished to the limits stipulated by standards.
Due to the importance of milk in the human diet, it is essential to increase milk production and ... more Due to the importance of milk in the human diet, it is essential to increase milk production and to improve its quality. In order to obtain a complex image of milk quality in Galati county there was made a study based on analyzing raw milk, from January until December 2010, taking into account the influences of animals feeding and conditions of transport and storage (including summer period, when the milk production is maximum, and autumn period, when milk production decreases). To determine the quality and safety of raw milk in Galati county there have been concerned: determinations of physical and chemical characteristics (density, protein content, lactose content, fat content, freezing point) and determinations of microbiological characteristics (total number of mesophyllic germs (NTG) and number of somatic cells (NCS)).
Food Chemistry, 2015
This study was carried to determine the influence of hot air drying process and combined methods ... more This study was carried to determine the influence of hot air drying process and combined methods on physicochemical properties of pumpkin (Cucurbita moschata) samples. The experiments in hot air chamber were lead at 50, 60 and 70°C. The combined method consists of a triple combination of the main drying techniques. Thus, in first stage the samples were dried in hot air convection at 60°C followed by hot air ventilation at 40°C simultaneous with microwave. The time required to reduce the moisture content to any given level was highly dependent on the drying conditions. So, the highest value of drying time in hot air has been 540min at 50°C, while the lowest time has been 189min in hot air combined by microwave at 40°C and a power of 315W. The samples dried by hot air shows a higher rehydration capacity than samples dried by combined method.
A total of 108 raw milk samples were collected from tankers arriving at processing facilities fro... more A total of 108 raw milk samples were collected from tankers arriving at processing facilities from rural areas in eastern and northern regions of Romania from January to December 2010. Concentrations of As, Cu, Zn and Pb in the samples were performed using an atomic absorption spectrophotometer. Detection and measurement of the organochlorine pesticides residues (α +β-HCH, γ-HCH and total DDT) were achieved by using a gas chromatograph equipped with a 63Ni electron capture detector. Pb contents in all samples corresponded to tolerance level (0.1 mg kg-1) and in 98% of these samples were below 0.05 mg kg-1. All samples examined for residues of Cu, Zn and As were completely acceptable as well. Residue levels of organochlorine pesticides in all analysed samples were far below tolerance levels, too. In 93.5% of samples α + β-HCH and in 85% of samples γ-HCH was below the limit of detection (0.008 mg kg-1). In 85% of samples total DDT residues were between < 0.005 and 0.0068 mg kg-1. I...
The purpose of this study was to determine from the three different varieties of apple (Golden De... more The purpose of this study was to determine from the three different varieties of apple (Golden Delicious, Jonathan and Starkrimson), which is best suited to storage at refrigeration temperature in constant conditions (5 °C and 85% relative humidity). In this order, the apples were stored in three variants of packages as bulk, packed in LDPE foil and alimentary paper for 23 days in a professional refrigerator. In this period, some textural and structural tests based on penetration and microstructure analyses were carried out with a 7-day frequency. As a conclusion of these tests the maximum values for mechanical determination are for Starkrimson variety 69.54 N at 4 mm depth for 15 days of storage while the minimum one is 24.34 N at 3 mm for Jonathan variety. The good part of the storage by refrigeration is the bulk variants there were no significant changes including quality damage, even the Starkrimson variety microstructure modification during refrigeration was the most affected.
The aim of this research was to investigate the effect of a cyanobacterial (Spirulina platensis) ... more The aim of this research was to investigate the effect of a cyanobacterial (Spirulina platensis) biomass on the microflora of a probiotic fermented dairy product during incubation and storage time. Spirulina-enriched and control fermented milks were produced using pasteurized milk, powder milk and two starter culture BB12 and LA-5. During incubation and storage time there were followed parameters as: the titratable acidity, the pH, the syneresis, the water holding capacity, the dynamic viscosity and the lactic bacteria number. The final product was stored at 5 ± 1°C for 15 days. The results showed that the Spirulina platensis biomass had a beneficial effect on the survival of the BB12 and LA-5 starter bacteria during the entire storage period. The abundance of bioactive substances in Spirulina platensis have great importance from a nutritional point of view because the cyanobacterial biomass provides a new opportunity for the production of functional dairy foods.
In this study there were analyzed three different varieties of apple Golden Delicious, Jonathan a... more In this study there were analyzed three different varieties of apple Golden Delicious, Jonathan and Starkrimson, which were stored by refrigeration in three variants (bulk, packed in LDPE foil and ordinary paper) in a professional refrigerator for 24 days. The penetration tests were lead to determine the mechanical properties including penetration force and the textural one as microstructure. The determinations were unrolled with a 7 days frequency. The values for penetration force associated with the sensorial attribute – firmness, applied to apple varieties range from 20.49 N for bulk Jonathan in the 7th day of refrigeration storage to 69.54 N for Starkrimson LDPE foil packed at the 14 th day. In case of textural modifications there were some sensitive differences between the three varieties, but the most affected structure was those for Starkrimson and even at the bulk storage there weren't quality deficiency, the packed apples were less influenced by refrigeration.
The study intends to determine the temperature variation of the apple puree treated by ohmic heat... more The study intends to determine the temperature variation of the apple puree treated by ohmic heating, the necessary time to reach the final purpose of the heating and the apple puree viscosity before and after ohmic heating, which has the role to facilitate some rheological parameters calculation. For heating, it was used a batch ohmic installation. The heating process has been driven at different voltage gradients from 15 to 20 V/cm; it was also observed the bubbling moment, which concurred with the finish of the ohmic heating process. Therefore, bubbling was observed in all cases above 60°C and the processing time depends on the voltage gradient. There were calculated also the correlation coefficients with the Statistica 8.0.
The objective of this research was to use Multiple Correspondence Analysis (MCA) for the design o... more The objective of this research was to use Multiple Correspondence Analysis (MCA) for the design of Cheese is the most complex and dynamic food products. By mixing fresh cheese with flavours or salt and other spices it could obtained fresh dairy appetiser type. Supplements used for the study were: dill, bunch onion, red pepper thinly minced (supplements were included in the coagulum). Fresh cow cheese was analysed by physico-chemical, rheological and sensorial point of view. The rheologic analysis of the starter type cheese that was produced aimed at establishing the variation of the dynamic viscosity depending on the share rate, as well as the variation of the share stress depending on the share rate. The variation of these parameters determined the rheologic behaviour of the starter-type cheese. During the sensorial analysis of the fresh cow cheese and supplements were taken into consideration the following characteristics: taste, scent, colour, consistency and the appearance.
Food Science and Biotechnology, 2015
ABSTRACT Inactivation of pectin methyl esterase was evaluated using thermal and ohmic treatments.... more ABSTRACT Inactivation of pectin methyl esterase was evaluated using thermal and ohmic treatments. Kinetics of enzyme inactivation in crude extracts during thermal treatment was described by a first order model yielding an activation energy of 202.52±25.86 kJ/mol. Pectin methylesterase was inactivated more rapidly by an ohmic treatment than by heating. A gradient of 25 V/cm was used to evaluate ohmic induced changes in color, reducing sugar concentrations, mineral and total polyphenolic contents, and rheological and morphological properties. A pseudo-plastic behavior was observed and the Power law was considered adequate to describe apple puree behavior. Minimal changes in physico-chemical parameters occurred. Ohmic treatment can be used in food processing and bioengineering for inactivation of quality-degrading enzymes and retention of health-related compounds and extension of the shelf-life.
Journal of Food Science and Technology, 2014
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014
Heat-induced structural changes of Aspergillus oryzae pectin methylesterase (PME) were studied by... more Heat-induced structural changes of Aspergillus oryzae pectin methylesterase (PME) were studied by means of fluorescence spectroscopy and molecular modeling, whereas the functional enzyme stability was monitored by inactivation studies. The fluorescence spectroscopy experiments were performed at two pH value (4.5 and 7.0). At both pH values, the phase diagrams were linear, indicating the presence of two molecular species induced by thermal treatment. A red shift of 7 nm was observed at neutral pH by increasing temperature up to 60°C, followed by a blue shift of 4 nm at 70°C, suggesting significant conformational rearrangements. The quenching experiments using acrylamide and iodide demonstrate a more flexible conformation of enzyme with increasing temperature, especially at neutral pH. The experimental results were complemented with atomic level observations on PME model behavior after performing molecular dynamics simulations at different temperatures. The inactivation kinetics of PME in buffer solutions was fitted using a first-order kinetics model, resulting in activation energy of 241.4±7.51 kJ mol(-1).
The Annals of the …, 2009
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Papers by Elisabeta Botez