Microencapsulated biofertilizer formulation: product development and effect on growth of green pepper seedlings

Aim of the study: This study aimed to formulate a novel, commercially applicable biofertilizer, to optimize the microencapsulation procedure of Bacillus subtilis NCIM 2063 and examine the stability and phytostimulatory effects of obtained formulation. Area of the study: Southestern Serbia. Material and methods: Microbial powder formulations were prepared using spray drying with maltodextrin as a carrier. The spray drying conditions were set according to Box-Benkhen experimental desing. The effect of the formulation was tested on green pepper (Capsicum annuum) seeds in controled conditions. Main results: Response surface models were developed. All of the models were statistically significant, adequately fitted and reproducible. The maximum achieved values of viability and yield in a formulation were 1.99·109 CFU/g and 96.8%, respectively, whilst the driest formulation had 1.44% moisture. The following optimum conditions were proposed for the spray drying procedure: an inlet air temperature of 133 °C, maltodextrin concentration of 50 g/L and a feed flow rate of 6.5 mL/min. The obtained microbial formulation had a high survival rate after being stored at room temperature over a 1--year period. Its application on green pepper seeds had beneficial effect on plant height, leaf dry weight and chlorophyll content of the seedlings. Research highlights: B. subtilis was successfully microencapsulated on maltodextrin as a carrier. Interaction effects between the process variables were fully explained and statistically significant models were developed. In addition to biocontrol properties formulation had a phytostimulatory effect, excellent stability and satisfactory physical properties. © 2022 CSIC

Freeze vs. Spray Drying for Dry Wild Thyme (Thymus serpyllum L.) Extract Formulations: The Impact of Gelatin as a Coating Material

Freeze drying was compared with spray drying regarding feasibility to process wild thyme drugs in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration and heat-, ultrasound-, and microwave-assisted extractions. Higher total powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% w/w) provided better TPC recovery by 70% in case of lyophilization and higher total powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53-75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation was distinguished from the others by a higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process mainly affected the position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray-dried formulations compared to freeze-dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and a higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151-223 µm) compared to small microspheres (~8 µm) in spray-dried powder

Depth from an image

Hoe zien mensen diepte in een afbeelding wanneer de scene in feite plat is gemaakt? Ons visueel systeem maakt gebruik van verschillende elementen in een afbeelding om diepte uit te rekenen. Dit is echter een complex proces, dat tot op heden geen volledige duidelijkheid biedt. Hoe kunnen we dit dan op de computer nabootsen, om automatisch diepte te kunnen afleiden? In dit proefschrift, zoeken we de grenzen op tot welke diepte berekend kan worden op basis van één afbeelding, gegeven de mogelijkheden van huidige computers en algoritmes. Eerst formuleren wij geometrische scènecategorieën, opgebouwd uit platte panelen en vergelijkbaar met scènes in theaters. Als we de computer leren een stagetype te herkennen voor elke afbeelding, kunnen we diepte benaderen in de afbeelding. Aanvullend bouwen we de kennis over diepte op uit primitieve afbeeldingselementen. We extraheren lange lijnen in een afbeelding en gebruiken kennis over perspectief om de locatie van maximale afbeeldingsdiepte te achterhalen. Tevens vinden we de randen van afbeeldingsoppervlakte en sorteren deze om te concluderen welke belangrijk zijn voor diepteanalyse. De methodes in het proefschrift en in de geraadpleegde literatuur tonen aan dat de computer goed in staat is diepte te begrijpen, ook op basis van enkele afbeelding

Stages As Models of Scene Geometry

Reconstruction of 3D scene geometry is an important element for scene understanding, autonomous vehicle and robot navigation, image retrieval, and 3D television. We propose accounting for the inherent structure of the visual world when trying to solve the scene reconstruction problem. Consequently, we identify geometric scene categorization as the first step toward robust and efficient depth estimation from single images. We introduce 15 typical 3D scene geometries called stages, each with a unique depth profile, which roughly correspond to a large majority of broadcast video frames. Stage information serves as a first approximation of global depth, narrowing down the search space in depth estimation and object localization. We propose different sets of low-level features for depth estimation, and perform stage classification on two diverse data sets of television broadcasts. Classification results demonstrate that stages can often be efficiently learned from low-dimensional image representations

Depth estimation via stage classification

We identify scene categorization as the first step towards efficient and robust depth estimation from single images. Categorizing the scene into one of the geometric classes greatly reduces the possibilities in subsequent phases. To that end, we introduce 15 typical 3D scene geometries, called stages, each having a unique depth profile and roughly corresponding to a large majority of all images. In this work, we do not attempt to derive a precise depth map, but only to decide on the appropriate stage. The subsequent phase of parameter estimation would result in a more detailed background depth profile

Stages As Models of Scene Geometry

Reconstruction of 3D scene geometry is an important element for scene understanding, autonomous vehicle and robot navigation, image retrieval, and 3D television. We propose accounting for the inherent structure of the visual world when trying to solve the scene reconstruction problem. Consequently, we identify geometric scene categorization as the first step toward robust and efficient depth estimation from single images. We introduce 15 typical 3D scene geometries called stages, each with a unique depth profile, which roughly correspond to a large majority of broadcast video frames. Stage information serves as a first approximation of global depth, narrowing down the search space in depth estimation and object localization. We propose different sets of low-level features for depth estimation, and perform stage classification on two diverse data sets of television broadcasts. Classification results demonstrate that stages can often be efficiently learned from low-dimensional image representations

Fermentation processes by immobilized cell systems in beverage production

Immobilized cell technology has been investigated and used in various bio-industries as well as in processes based on alcoholic fermentation, like beer, wine and cider fermentation processes. Some of the most important reasons that favour immobilized over suspended cell systems include faster fermentation rates, increased volumetric productivity, and possibility for continuous operation. In spite of the fact the immobilized yeast technology was paying continual attention in these industries over the last 30 years, today, this technology is well established in very limited number of cases such as secondary beer fermentation and alcoholfree and low-alcohol beer production as well as sparkling wine production. However, in some more complex processes with various side reactions that effect flavour formation and final product quality, like primary beer fermentation, wine and cider fermentation, immobilized cell technology is still under scrutiny on the lab or pilot levels. Immobilized cell phisiology control and fine-tuning of the flavour compounds formation during the long term fermentation processes remain the major challenges for successful application of immobilized cell technology on an industrial scale. This paper describes and discusses the key factors for the implementation of this technology on an industrial level, like carrier materials, immobilization technology and bioreactor design

Encapsulation Systems in the Food Industry

Encapsulation is a useful tool to improve the delivery of bioactive and living cells into foods. Encapsulation aims to preserve the stability of the active compounds during processing and storage and to prevent undesirable interactions with the food matrix. In addition, encapsulation may be used to immobilise cells or enzymes in food processing applications, such as fermentation processes and metabolite production processes. This chapter aims to provide an overview of commonly used processes to encapsulate food actives and numerous reasons for employing encapsulation technologies. The most widely used materials for the design of protective shells of encapsulates are presented (polysaccharides, their derivatives, plant exudates, marine extracts, proteins and lipids) with a special focus on requirements such as food-grade purity, biodegradability and the ability to form a barrier between the internal phase and its surroundings. A number of techniques are available for encapsulation in the food industry. Spray drying is the most extensively applied encapsulation technique on an industrial scale; the other encapsulates are prepared by, for example, spray-chilling, freeze-drying, melt extrusion, and melt injection