Joanna Bryś

Determination of lipid and phenolic fraction in two hazelnut (Corylus avellana L.) cultivars grown in Poland

The fatty acid, tocopherol, sterol, phospholipid and phenolic compositions of Polish hazelnuts (Kataloński and Webba Cenny) were examined. Particularly, free+esterified and bound tocopherol, sterol and phenolic compounds were determined. The major fatty acids found in hazelnuts were oleic and linoleic acids. α-Tocopherol was the most abundant tocopherol accounting for 90-92% of the total content. Bound tocopherols represented 45.5% and 21.7% of total tocopherols in Kataloński and Webba Cenny cultivar, respectively. Total free+esterified sterols were between 62.0% and 75.7% of total sterols and β-sitosterol was the first sterol in the two samples. Phosphatidylcholine was the most common phospholipid, accounting for 72.2% for Kataloński and 67.5% Webba Cenny, respectively. The most abundant fatty acids in the phospholipid fraction were oleic equally with palmitic acids. Twelve free and six bound phenolic compounds were identified and quantified in hazelnut kernel, instead nine free and six bound phenolic compounds were determined in hard shell.

Oxidative stability and triacylglycerols structure of lipid fraction from cookies for infants

The aim of this research was to analyse the quality of the lipid fraction extracted from commercially available cookies intended for infants. The composition, fatty acid distribution and oxidative stability of fats, interpreted as the resistance of fats against autooxidation, were studied. In addition, the kinetic parameters of the oxidation process, such as activation energies (Ea), pre-exponential factors (Z) and reaction rate constants (k) for fat oxidation under the differential scanning calorimetry tests conditions were calculated using the Ozawa–Flynn–Wall method and the Arrhenius equation. The distribution of fatty acids in the tested cookies is similar to that present in most of infant formulas, but differs significantly from that in human milk. Based on the results obtained, high oxidative stability of tested fats can be observed. The Ea values ranged from 86.22 to 116.13 kJ/mol; Z from 1.95 × 109 to 1.05 × 1013; and k values ranged from 5.70 × 10− 4 min− 1 at 100°C to 2.12 × 10− 1 min− 1 at 170°C.

The influence of trehalose–maltodextrin and lactose–maltodextrin matrices on thermal and sorption properties of spray-dried β-lactoglobulin–vitamin D3 complexes

In the study, the effect of lactose–maltodextrin and trehalose–maltodextrin matrices on the glass transition temperatures and moisture sorption characteristics of spray-dried β-lactoglobulin–vitamin D3 complexes was investigated. Incorporation of sugars into complexes can influence the thermal properties and moisture sorption characteristics of powders. The glass transition temperature as an important physiochemical parameter that determines the processing conditions, product quality and stability of the final product was studied with the use of modulated differential scanning calorimetry method. Moisture sorption isotherms, water activity and moisture content as parameters related to sorption properties, were also investigated. Additionally, particle size, wettability and insolubility index were studied to characterise newly synthesized products. For the samples tested, two well-separated glass transitions were found. The dominant effect of maltodextrin on the glass transition temperatures was observed. An increase in the percentage of maltodextrin added resulted in increasing Tg value of studied complexes. At low water activity all powdered complexes showed typical sorption behaviour of food systems. Trehalose as a carbohydrate component of powdered complexes, in comparison to lactose, delayed the occurrence of crystallization.

Effect of composition and drying method on glass transition temperature, water sorption characteristics and surface morphology of newly designed β-lactoglobulin/retinyl palmitate/disaccharides systems

In the study, MDSC method was used to evaluate thermal properties of β-lactoglobulin–retinyl palmitate products enriched in disaccharides. Additionally, sorption behavior of powders was determined to define their stability. The obtained powders were also examined and visualized with scanning electron microscopy to find the relationship between food processing conditions and morphological changes in products. For the samples tested, a single glass transition was observed. The results have shown the impact of the composition of studied samples on the glass transition temperatures. The carbohydrate- β-lactoglobulin systems were characterized by higher Tg values than disaccharides alone. At low water activity, all powdered complexes showed typical sorption behavior of food systems with the sigmoidal shape of the curve. The present study has shown that spray-dried and freeze-dried powdered products with lactose or trehalose have different time-dependent crystallization behavior. Trehalose as a carbohydrate component of samples, in comparison with lactose, delayed the occurrence of crystallization. The obtained images presented the dependence of the shape of the particles on the drying method used. Spray-dried powders were characterized by a spherical or close to spherical structure with the surface of larger particles often deformed. In the case of freeze-dried particles, irregular structures were observed.

Torulene and torularhodin: “new” fungal carotenoids for industry?

Torulene and torularhodin represent the group of carotenoids and are synthesized by yeasts and fungi. The most important producers of these two compounds include yeasts of Rhodotorula and Sporobolomyces genera. The first reports confirming the presence of torulene and torularhodin in the cells of microorganisms date to the 1930s and 1940s; however, only in the past few years, the number of works describing the properties of these compounds increased. These compounds have strong anti-oxidative and anti-microbial properties, and thus may be successfully used as food, feedstock, and cosmetics additives. In addition, tests performed on rats and mice showed that both torulene and torularhodin have anti-cancerous properties. In order to commercialize the production of these two carotenoids, it is necessary to obtain highly efficient yeast strains, for example, via mutagenization and optimization of cultivation conditions. Further studies on the activity of torulene and torularhodin on the human body are also needed.

Analysis of Potential Related to Grass-Derived Biomass for Energetic Purposes

According to the climate energy package of the EU, biomass is and will be the most important source of energy of all renewable resources of energy (RRE). Experts from the European Association of Biomass estimate that it will be caused by tree-fold increase in demand for this source of energy (Gradziuk in Gospodarcze znaczenie i mozliwości wykorzystania slomy na cele energetyczne w Polsce. Wyd. Instytut Uprawy Nawozenia i Gleboznawstwa - Panstwowy Instytut Badawczy w Pulawach, 2015, [1]). In Poland, the wastelands cover 475,000 ha (Central Statistical Office of Poland. Statistical Yearbook of Agriculture, 2016, [2]), and could be used as a source of biomass, e.g. for biogas plants or for briquette production. Waste grass from green areas such as parks, gardens, garden plots, and biomass from roadsides (motorways and highways) should also be taken into account. The amount of waste changes annually as it depends on vegetation, weather, method of green areas and gardens nurturing. Green waste is mainly produced from spring till autumn, and the amount produced during these seasons is much higher than in winter (Jedrczak, Biologiczne przetwarzania odpadow. Wydawnictwo Naukowe PWN, Warszawa, 2007, [3]). Therefore, grass briquetting is desirable as briquetted grass may be used throughout the year. One of the most important stages of briquette production is drying raw material, i.e. grass.