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The paper presents a new method for the reduction of waste production during juice processing through the reformulation of cloudy juices by ultrafiltration (UF), resulting in simultaneous production of a new type of cloudy juice of reduced sugar content. In contrast to the traditional juice production process, the final product was UF retentate. During UF, sugars were partially removed, while fibre and other macromolecular components present in a cloudy fraction, with health-promoting properties, were retained. Such treatment gives the possibility to reduce waste production during juice processing, because in the traditional approach, the cloudy fraction is usually treated as a waste after the clarification step. After UF in apple cloudy juice, the total content of soluble solids and sugars decreased from the initial values 11.0% and 10.4% to 9.2% and 8.8%, respectively; while in apple-beetroot cloudy juice, it reduced from 11.4% and 8.2% to 8.7% and 5.8%, respectively. At the same time, the cloudy fraction was retained and concentrated. The retention of soluble solids and sugars after the UF of apple juice was 66% and 67%, respectively, that is, 34% of soluble solids and 33% of the sugars were removed to the permeate. In apple-beetroot juice, 68% and 71% of soluble solids and sugars was retained, respectively.

BACKGROUND: Sour cherry juice concentrate powder can serve as a modern, easy‐to‐handle, phenolics‐rich merchandise; however, its transformation into powdered form requires the addition of carriers. In line with the latest trends in food technology, this study valorizes the use of dairy by‐products (whey protein concentrate, whey, buttermilk, and mixes with maltodextrin) as carriers. A new multiple approach for higher drying yield, phenolics retention (phenolic acids, flavonols and anthocyanins) and antioxidant capacity of powders were tested as an effect of simultaneous decrease of drying temperature due to the drying air dehumidification and lower carrier content. RESULTS: Dairy‐based carriers were effective for spray drying of sour cherry‐juice concentrate. The drying yield was increased and retention of phenolics was higher when compared with maltodextrin. The application of dehumidified air, which enabled the drying temperature to be reduced, affected drying yield positively, and also affected particle morphology and retention of phenolics (the phenolic content was approximately 30% higher than with spray drying). CONCLUSIONS: The study proved that it is possible to apply dairy‐based by‐products to produce sour cherry juice concentrate powders profitably, lowering the spray‐drying temperature and changing the carrier content. Dehumidified air spray drying can be recommended for the production of fruit juice concentrate powders with improved physicochemical properties. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Spray drying of sugar-rich foods causes problems, related mainly to low glass transition temperature, which is manifested by high stickiness, lower drying efficiency, and yield. Thus, a number of research papers have been published recently on this topic. This study summarizes the obtained results and indicates possible future directions. The most popular method to overcome the stickiness problem is still the application of carriers. However, in addition to conventional carriers like maltodextrin and gum Arabic, novel carriers are also being tested. The carriers with additional health-promoting properties are the most interesting group. In the material-science approach the application of proteins as anti-stickiness agents can also be mentioned. Moreover, the raw materials can be modified by membrane techniques to reduce sugar content and increase glass transition temperature. In the process-based approach, the main efforts are mostly focused on decreasing of drying temperature. Currently, the use of dehumidified air has been successfully verified as a possible way to reduce drying temperature. The reduction of stickiness achieved by this method allows to minimize the amounts of carriers added into the feed before spray drying. [ABSTRACT FROM AUTHOR]

Summary: Alcea flower (as a natural source of antioxidants and colour) polyphenols might be easily deteriorated during processing and preservation. So, encapsulation is a suitable approach to overcome this problem. In this study, Alcea flower extract (AFE) was encapsulated using different carriers (maltodextrin (MD) and MD with gum arabic (GA), whey protein concentrate (WPC), and GA‐WPC). The production yield (~70%) was higher when MD‐WPC mixture or MD alone were used. The moisture content, water activity (aw), and wettability time of samples containing MD were less than other samples while their solubility was higher. Bulk and tapped density and also hygroscopicity were lowest in the samples produced using MD‐WPC, with improved flowability. The morphological characteristics of particles (matrix‐type particles with smooth and spherical surfaces in MD samples and wrinkled and indented in protein carriers) were affected by the carrier composition. Chemical structure evaluation (FTIR) indicated the successful coating of polyphenols in the carrier matrix. Generally, TPC (0.93 mg GAE mL−1) and retention of DPPH (82.4%), ABTS (94.1%), hydroxyl radical scavenging (77.2%) and reducing power (87.5%) of the samples produced with MD‐WPC were higher than other carriers. [ABSTRACT FROM AUTHOR]

The application of low-temperature, dehumidified air-assisted spray drying was evaluated as a method to produce carrierfree powders of selected sugar-rich and acid-rich food materials: blackcurrant juice concentrate, mango puree, purple carrot juice concentrate, sauerkraut juice, kiwiberry pulp, and tomato pulp. As a consequence of decreased drying air humidity, inlet/outlet air temperature was lowered to 80/55°C. In order to validate this new approach, the conventional spray drying was conducted as well at 180/80°C inlet/outlet air temperature. The powder recovery, physical properties and color parameters of powders were determined. For blackcurrant juice concentrate, mango puree, purple carrot juice concentrate and sauerkraut juice it was possible to obtain carrier-free powders only by low-temperature drying, while for kiwiberry pulp and tomato pulp both variants of spray drying were effective. Decreased drying temperature positively influenced some properties of powders; i.e., median particle size diameter and hygroscopicity of the powders obtained by spray drying with dehumidified air were lower compared to those of the powders dried by conventional spray drying. Carrier-free powders of some raw materials (blackcurrant juice concentrate, mango puree, purple carrot juice concentrate, sauerkraut juice) were spray dried solely with dehumidified air, underlining its importance in the production of "clean label" products. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the possibility of honey spray drying with addition of maltodextrin and gum Arabic as drying agents. The influence of the concentration of the solution subjected to drying, the type and content of the drying agents upon the physical properties of obtained powders was examined. An attempt was undertaken to obtain powder with a honey content of more than 50% d.b. Spray drying of multifloral honey with the addition of maltodextrin and gum Arabic was carried out at inlet air temperature of 180°C, feed rate of 1 mL/s and rotational speed of a disc atomizer of 39,000 rpm. The properties of obtained powders were quantified in terms of moisture content, bulk density, Hausner ratio, apparent density, hygroscopicity and wettability. Using gum Arabic it was possible to obtain a product with a higher content of honey (67% solids) than in the case of maltodextrin (50% d.b.). However, the powders obtained with gum Arabic were characterised by worse physical properties: higher hygroscopicity and cohesion, and longer wetting time.

Spray drying of sour cherry juice concentrate was performed by conventional high temperature method (180 °C/80 °C, inlet/outlet air), as well as by innovative approach with dehumidified air and low drying temperature (80 °C/45 °C, inlet/outlet air). Moreover, the possibility to apply pea protein as an alternative carrier to partially replaced maltodextrin was tested. Due to lower drying temperature and reduced stickiness the carrier content was reduced from 50% down to 30% solids to enhance powders physiochemical properties (lower stickiness, hygroscopicity, better color, better bioaccessibility), although some parameters of variants produced with the addition of pea protein had poorer quality in comparison to powders with only maltodextrin (moisture content, water activity, particles morphology and size, glass transition temperature). Increased bioaccessibility of phenolics and antioxidant potential of pea protein-enriched samples indicated the potentially possible application in functional food. [ABSTRACT FROM AUTHOR]