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Abstract
Membrane filtration has a promising advantage in the processing of egg products. In this study, liquid egg whites (LEW) were separately concentrated by using reverse osmosis (RO) and ultrafiltration (UF) techniques. The first aim of this research was to determine the effects of the concentration pre-treatments on the physico-chemical quality criteria (pH, relative whipping capacity, foaming stability, water holding capacity-WHC, colour) and the rheological behaviour (viscosity, oscillation) of LEW samples. The second aim of this research was to investigate the impact of the membrane pre-treatment on meringue's functional quality attributes such as meringue batter density and meringue batter colour values (L*, a*, b*). The average dry matter of LEW was increased from 12% to 23% by the concentration pre-treatment process (RO and UF), and water was removed from the LEW. In addition, the batter density of meringue cookie samples was 0.37 ± 0.01 g mL−1 in UF and RO. The differences between the pH and dry matter values of the ultrafiltration and reverse osmosis treated groups were found to be statistically similar, and it was observed that the elastic modulus (G′) increased with the increase in frequency in the rheological measurements. It has been determined that G′ is higher than G″ in all samples. An elastic/solid-like (G′ > G″) structural behaviour was determined while increasing the frequency value. It was determined that the WHC of LEW treated with RO was higher than of the group treated with UF. The results of the study showed that while reducing transportation and storage costs, the water content of >80% of LEW (raw material-the treated liquid egg white) removed by UF and RO applications can be suitable to produce meringue batter cookies (semi-finished product).
Abstract
For a long time, olive oil has been considered for formulation of biopharmaceuticals and received a prestigious place in cuisine for its unique organoleptic and nutritional properties. Nevertheless, oxidation of fatty acids in olive oil provides short shelf-life and undesirable organoleptic properties. Thus, microencapsulation of olive oil is a considerable promising approach to maintain its quality and biological activities. The objective of this investigation was to prepare extra virgin olive oil microcapsule by sequential technologies, such as water emulsification of olive oil with wall material (matrix) and freeze drying of emulsion. The effect of wall material composition was examined to prepare microcapsule of extra virgin olive oil. Different ratios of wall materials such as maltodextrin (MD), carboxymethyl cellulose (CMC), and gum arabic (GA) were used. Furthermore, effects of emulsification technologies, such as homogenisation with rotor–stator homogeniser (RSH) and cross-flow membrane emulsification (CFME) were investigated. The stability of emulsion was higher when emulsion was prepared by RSH; however, the droplet mean diameter (D32) was lower in case of RSH compared to CFME. The highest encapsulation efficiency (EE) was found as 68.96 ± 2.6% when CFME was adopted and composition of wall materials was 15 g MD, 15 g GA, and 5 g CMC.
Abstract
Rye is an important raw material of bread due to tradition and its favourable nutritional and technological qualities. Despite the beneficial fibre composition, a special group of short-chain carbohydrates, the so called FODMAPs (fermentable oligo-, di-, monosaccharides and polyols) may cause problems for patients with irritable bowel syndrome. The aim of our work was to investigate the non-starch carbohydrate (dietary fibre compounds, short-chain carbohydrates) composition of rye varieties, and of their novel milling fractions obtained from industrial milling trials and test loaves made from them. Regarding fibre and short chain carbohydrate composition, rye varieties did not show significant differences. In new subfractions, fibre and FODMAP composition were described, among profiles most of them differ from commonly used flours, independently from variety. The yeast fermentation and baking caused a decrease in water-extractable arabinoxylan content, at the same time increased the substitution pattern of water-extractable arabinoxylans. Furthermore, breadmaking process decreased the fructan content, and therefore increased the fructose level, thus modifying the short-chain carbohydrate composition. Based on our knowledge, this research is among the first ones investigating the fibre and short-chain composition of rye from the seeds to the consumable final products.
Abstract
Coatings of rice flour (RF), reinforced or not with rosemary essential oil (ROS), were used to evaluate changes in the internal quality of quail eggs stored at room temperature. Quality parameters [egg weight loss (EWL, %), Haugh unit (HU), yolk index (YI), albumen and yolk pH], microbiological (counts of total aerobic mesophilic bacteria and Enterobacteriaceae) and sensory (colour, aroma, odour, texture, taste, and general acceptability) parameters were evaluated during the experiment. Compared to the number of total aerobic mesophilic bacteria on the shell of uncoated eggs (2.02 ± 0.49; 1.78 ± 0.20 log10 CFU mL−1), RF/ROS exhibited significant inhibition effects for these bacteria on 0. (1.16 ± 0.25 log10 CFU mL−1) and 21. (0.84 ± 0.11 log10 CFU mL−1) days of storage at room temperature. On days 7, 14, and 21, RF had no effect on HU (P > 0.05), but eggs coated with RF/ROS had significantly higher HU (P < 0.05) than uncoated eggs from day 14, maintaining grade AA (73.88 ± 2.67) on day 21, while uncoated eggs had grade A (68.90 ± 1.55) at that time. The RF coating reinforced with ROS was a bioactive, efficient, and safe formulation for application based on internal quality, microbiological and sensorial aspects of quail eggs.
Abstract
Flagellation is one of the major virulence factors of Campylobacter jejuni (C. jejuni), enabling bacterial cells to swarm in rather high viscous fluids. The aim of this study was to determine the impact of the surrounding viscosity on the expression of motility related genes of C. jejuni. Therefore, bacterial RNA was extracted from liquid cultures as well as from bacterial cells recovered from the edge and the center of a swarming halo from high viscous media. The expression pattern of selected flagellar and chemotaxis related genes was investigated by RT-PCR. Higher mRNA levels of class 1 and lower levels of class 2 and 3 flagellar assembly genes were detected in cells derived from the edge of a swarming halo than in cells from the center. This indicates different growth states at both locations within the swarming halo. Furthermore, higher mRNA levels for energy taxis and motor complex monomer genes were detected in high viscous media compared to liquid culture, indicating higher demand of energy if C. jejuni cells were cultivated in high viscous media. The impact of the surrounding viscosity should be considered in future studies regarding motility related questions.
Abstract
Pectobacteriaceae are plant pathogens responsible for serious diseases on many crops of interest including potato. Currently, regarding the several disadvantages of conventional control by chemicals, the application of bio-agents as alternatives is increasingly being explored. The present investigation was conducted in order to evaluate the antibacterial activity of the fungal strain Trichoderma asperellum T34 as an antagonist against phytopathogen Dickeya solani on tubers of three potato varieties (Agata, Monalisa, and Picobello). For this, half-tubers were inoculated by T34 suspension with concentrations of 103 and 105 cells mL−1 at 6, 9, and 12 h before bacterial infection (D. solani at concentrations of 107 and 108 cfu mL−1). The results of infection assays without the antagonist indicated that Picobello variety was the least sensitive to soft rot, Monalisa and Agata varieties showed medium and high sensitivity, respectively. The antagonism assays revealed strong antibacterial activities, manifested by the regression of softened tissues gradually with the time of preincubation with T34, leading to a complete disappearance of disease symptoms using 12 h. Hence, the application of antagonistic Trichoderma strains as antimicrobial agents in the control of harmful plant pathogens is a subject of great interest and can be considered a promising strategy to handle soft rot diseases.
Abstract
Germalus kozari sp. nov. (Hemiptera: Heteroptera: Lygaeoidea: Geocoridae) is now described. Comparative notes, keys, diagnoses, and distribution data to allied Indomalayan species is provided. Germalus greeni is reported for the first time from outside of India and Sri Lanka.
Abstract
Nemoura kozari sp. n. is described on the basis of morphology of male adults collected in the Eastern Carpathians. The new species is classified as a member of the Nemoura marginata species group. It was found in medium elevations of the Krasna Mts, Ukraine, and the Rodna Mts, Romania, inhabiting slowly flowing, small brooks. New diagnosis of the marginata group and enumeration of its members are provided.