Ingrid Bauman

Rehydration ratio of fluid bed-dried vegetables

Fluid-bed drying of vegetable pieces has been investigated. The vegetables used have been potatoes, parsley roots, celery roots and carrots of various dimensions. Starting water content was: potatoes 78%, parsley roots 85.1%, celery roots 93.6%, and carrots 88.6%. Temperatures of fluidisation have varied from 60‡ to 100‡C at velocities of 0.71 ms-1. The goal has been to obtain dry vegetables with 6% to 10% water content and of good rehydration quality. Experimental data (bed height, gas temperature and velocity, pressure drop over the bed, drying time) have been measured and relevant values have been calculated. The results have shown that drying of vegetables in a fluidized bed produces dry vegetable pieces of excellent quality in a much shorter time than in continuous belt-dryers which are generally used

Flow Properties of Commonly Used Food Powders and Their Mixtures

The aim of this study was to get an insight on flow properties of five different food powders and their mixtures frequently used in industrial production of foodstuffs and in households. The studied food powders were flour, maize semolina, sugar, cocoa, and skim milk powder together with their mixtures. Based on cohesion index, samples were categorized as follows: easy flowing—sugar powder, skim milk powder, maize semolina, and mixture 3 (wheat flour and sugar powder); cohesive—flour and mixture 1 (wheat flour and maize semolina); very cohesive—mixture 4 (wheat flour, cocoa, and sugar powder), and extremely cohesive—cocoa powder and mixture 2 (cocoa, sugar, and skim milk powder). Based on powder flow speed dependency test, positive multiple correlations were found between four powder mixtures and their basic components at all speeds. Flour, maize semolina, and mixtures 1 and 3 did not show any susceptibility to caking, while sugar, skim milk powder, cocoa powder, and mixtures 2 and 4 showed an increasing cake height ratio indicating their susceptibility to caking.

Time and speed of fruit drying on batch fluid-beds

Drying of particles (pieces) in a fluidized bed affords better quality of end products, especially for better product structure and its shorter reconstitution time. Fluid-bed drying of different fruit particles has been investigated. Starting water content varies from grape berries 81.5% and peach 87.7% to apricot 86.9%. The temperature of fluidization varies from 70°C to 100°C at air velocities from 0.98 ms−1 to 5.2 ms−1. The product should be dried fruit with 10% to 14% of water content with good rehydration quality that varies from 8 to 20. Experimental data have been measured, relevant values have been calculated and a mathematical model introduced. The results have shown that drying of fruit in a fluidized bed produces dry fruit particles of improved quality in a much shorter time, with improved rehydration times and qualities, than in continuous belt-driers that are generally used.

Physical Properties of Non-Agglomerated Cocoa Drink Powder Mixtures Containing Various Types of Sugar and Sweetener

Characterization of flow properties represents a crucial step in the production of powdered composite mixtures. Mixing of cocoa powders with different sugars is the first step in the production of this type of beverages, which leads to a change in the mixtures flow properties. The objective of this work was firstly to determine the physical properties of non-agglomerated powdered cocoa and sugar mixtures and, after that, to determine which physical properties of cocoa powders are influenced by sugar addition and in what way they are influenced by sugars. Mixtures were formulated by two cocoa powders containing different amounts of fat and 11 different kinds of sugar or sweetener. A significant change was found in the median diameter, poured bulk density, compression and decompression force of the mixtures compared to the sole components’ physical properties. All the mixtures display a decreasing compaction coefficient with increase of flow speed, which indicates that these powder mixtures flow more freely at higher transport speeds. An increase of cake height ratio was detected in all the mixtures, indicating that all the mixtures were susceptible to caking and that they formed a strong cake. Insolubility of the mixtures was influenced significantly by the median diameter of the sugar particles added to the mixture. Addition of sugars and sweeteners to the cocoa powder reduced the red and yellow colour components, but the type of sugar or sweetener did not produce a considerable difference in the colour of the cocoa drink mixtures.

Assessment of Drying Characteristics and Texture in Relation with Micromorphological Traits of Carob Pods and Seeds (Ceratonia silliqua L.)

Carob tree (Ceratonia siliqua L.) is a perennial leguminous evergreen tree native to the coastal regions of the Mediterranean basin and is considered to be an important component of vegetation for economic and environmental reasons. Two constituents of the pod, pulp and seeds, can be used as feed or in food production. In this study, drying characteristics, texture and microstructure of carob pods were studied. Three different carob samples were prepared: whole carob pod, carob pod parts and carob seed. The drying experiments and the modelling showed that carob seeds had the highest drying rate, followed by pod parts and the whole, intact carob fruit. Texture studies showed that the maximum compression force depended on the area of the carob fruit on which compression tests were performed. The seeds showed the highest compression force, followed by the stem zone, the tip and the centre of the fruit. Differences in drying behaviour and texture of carob pods can successfully be interpreted by the micromorphology of the carob pods and seeds. Determining the drying rate, maximum compressive force and micromorphological traits is of great importance for further carob processing (e.g. milling, sieving, carob bean gum production or usage in food or feed products).

Flow properties and chemical composition of carob (Ceratonia siliqua L.) flours as related to particle size and seed presence

Due to abundance in carbohydrates, dietary fibres and bioactive compounds, as well as for its outspread and low prices, carob (Ceratonia siliqua L.) flour has a great potential of use as a functional ingredient. The aim of this study was to analyse this potential by physical and chemical properties assessment of different particle sizes of carob flour with and without seeds. The influence of seed presence on physical and chemical properties of flour was also investigated. Seed presence in carob flour led to higher cohesivity and cake strength. It also affected the extraction efficiency of polyphenols, which was confirmed by the ranking of samples according to their procyanidin and tannins contents. With regard to the carbohydrate content, significant differences (P<0.05) between the contents of fructose and glucose was established in samples differing by the presence of carob seeds. Spearman rank order correlations revealed a significant difference (P<0.05) between physical and chemical properties of carob flours. These findings confirm the importance of understanding physical and chemical properties of carob flours in order to use them efficiently as a functional food ingredient.

Fortification of instant coffee beverages - influence of functional ingredients, packaging material and storage time on physical properties of newly formulated, enriched instant coffee powders.

BACKGROUND Consumer demands for healthy, functional foods are growing rapidly nowadays. Coffee, as one of the most widespread commodities, represents an interesting aspect for enrichment, since it is consumed by millions of people on a daily basis. The aim of this study was to formulate enriched instant coffee powders with the purpose of estimating the influence of storage time, functional ingredients and packaging material on physical and sensory properties of the mixtures. RESULTS Storage time of 6 months significantly (P <0.05) influenced moisture content of the mixtures, which rose linearly with an increase in storage time. Packaging material proved to be an important variable affecting moisture content, particle size, colour and cohesion index. Functional ingredients (vitamins A and C, iron, inulin and oligofructose) influenced particle size, dispersibility, wettability and, in terms of sensory analysis, grades for aftertaste, chemical taste and overall acceptability. CONCLUSION Addition of functional ingredients significantly influenced some particle size distribution parameters and reconstitution properties, causing an increase in wettability and dispersibility times. Furthermore, in sensory terms, it influenced aftertaste and chemical taste grades. Packaging material significantly influenced moisture content, some particle size distribution parameters, colour and cohesion index.

Classification and Processing Optimization of Barley Milk Production Using NIR Spectroscopy, Particle Size, and Total Dissolved Solids Analysis

Barley is a grain whose consumption has a significant nutritional benefit for human health as a very good source of dietary fibre, minerals, vitamins, and phenolic and phytic acids. Nowadays, it is more and more often used in the production of plant milk, which is used to replace cow milk in the diet by an increasing number of consumers. The aim of the study was to classify barley milk and determine the optimal processing conditions in barley milk production based on NIR spectra, particle size, and total dissolved solids analysis. Standard recipe for barley milk was used without added additives. Barley grain was ground and mixed in a blender for 15, 30, 45, and 60 seconds. The samples were filtered and particle size of the grains was determined by laser diffraction particle sizing. The plant milk was also analysed using near infrared spectroscopy (NIRS), in the range from 904 to 1699 nm. Furthermore, conductivity of each sample was determined and microphotographs were taken in order to identify the structure of fat globules and particles in the barley milk. NIR spectra, particle size distribution, and conductivity results all point to 45 seconds as the optimal blending time, since further blending results in the saturation of the samples.

Assessment of Drying Characteristics and Texture in Relation with Micromorphological Traits of Carob (Ceratonia silliqua L.) Pods and Seeds.

Carob tree (Ceratonia siliqua L.) is a perennial leguminous evergreen tree native to the coastal regions of the Mediterranean basin and is considered to be an important component of vegetation for economic and environmental reasons. Two constituents of the pod, pulp and seeds, can be used as feed or in food production. In this study, drying characteristics, texture and microstructure of carob pods were studied. Three different carob samples were prepared: whole carob pod, carob pod parts and carob seed. The drying experiments and the modelling showed that carob seeds had the highest drying rate, followed by pod parts and the whole, intact carob fruit. Texture studies showed that the maximum compression force depended on the area of the carob fruit on which compression tests were performed. The seeds showed the highest compression force, followed by the stem zone, the tip and the centre of the fruit. Differences in drying behaviour and texture of carob pods can successfully be interpreted by the micromorphology of the carob pods and seeds. Determining the drying rate, maximum compressive force and micromorphological traits is of great importance for further carob processing (e.g. milling, sieving, carob bean gum production or usage in food or feed products).

Analiza utjecaja mikromorfoloških obilježja plodova i sjemenki na karakteristike sušenja i teksturu rogača (Ceratonia siliqua L.)

Carob tree (Ceratonia siliqua L.) is a perennial leguminous evergreen tree native to the coastal regions of the Mediterranean basin and is considered to be an important component of vegetation for economic and environmental reasons. Two constituents of the pod, pulp and seeds, can be used as feed or in food production. In this study, drying characteristics, texture and microstructure of carob pods were studied. Three different carob samples were prepared: whole carob pod, carob pod parts and carob seed. The drying experiments and the modelling showed that carob seeds had the highest drying rate, followed by pod parts and the whole, intact carob fruit. Texture studies showed that the maximum compression force depended on the area of the carob fruit on which compression tests were performed. The seeds showed the highest compression force, followed by the stem zone, the tip and the centre of the fruit. Differences in drying behaviour and texture of carob pods can successfully be interpreted by the micromorphology of the carob pods and seeds. Determining the drying rate, maximum compressive force and micromorphological traits is of great importance for further carob processing (e.g. milling, sieving, carob bean gum production or usage in food or feed products).