Karolina Szulc

Effect of Agglomeration on Flowability of Baby Food Powders

The aim of this study was to investigate the influence of the wet agglomeration in a fluidized bed on flowability of agglomerated products, such as baby food powders. The agglomeration process was performed in the fluidized bed. The wetting liquid used to the process was: water, 2% lecithin solution, and 50% sugar solution. Food powders flowability was expressed as: Hausner Ratio, pouring time, angles of sliding and of repose and flow function. The composition of materials, used to prepare mixtures, has a significant influence on tested properties. The higher milk powder of the mixtures caused decreasing of their flowability. Wet agglomeration of baby food powders caused an increase in the mean diameter of particles, which made it possible to receive agglomerates with good flowability and decreased bulk density. The increase of milk powder content from 0 to 73% in the mixture before the agglomeration contributed to improve its flowability. Wet agglomeration with 2% lecithin solution and 50% sugar solution reduced particle size and bulk density, improved flowability of received agglomerates in relation to agglomerates received with water as a wetting liquid.

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.

Effect of composition on physical properties of food powders

Abstract The paper presents an influence of raw material composition and technological process applied on selected physical properties of food powders. Powdered multi-component nutrients were subjected to the process of mixing, agglomeration, coating, and drying. Wetting liquids ie water and a 15% water lactose solution, were used in agglomeration and coating. The analyzed food powders were characterized by differentiated physical properties, including especially: particle size, bulk density, wettability, and dispersibility. The raw material composition of the studied nutrients exerted a statistically significant influence on their physical properties. Agglomeration as well as coating of food powders caused a significant increase in particle size, decreased bulk density, increased apparent density and porosity, and deterioration in flowability in comparison with non-agglomerated nutrients.