Effects of Sequential Induction Combining Thermal Treatment with Ultrasound or High Hydrostatic Pressure on the Physicochemical and Mechanical Properties of Pea Protein-Psyllium Hydrogels as Elderberry Extract Carriers.

Entrapping bioactive ingredients like elderberry extract in hydrogels improves their stability and functionality in food matrices. This study assessed the effect of sequential thermal treatment with ultrasound (US) or high hydrostatic pressure (HHP) and treatment duration on pea protein-psyllium hydrogels as elderberry extract carriers. Measurements included color parameters, extract entrapment efficiency, physical stability, textural properties, microrheology, FT-IR, thermal degradation (TGA), SEM images, total polyphenols content, antioxidant activity, and reducing power. The control hydrogel was obtained using only thermal induction. Both treatments impacted physical stability by affecting biopolymer aggregate structures. Thermal and US combined induction resulted in hydrogels with noticeable color changes and reduced entrapment efficiency. Conversely, thermal and HHP-combined induction, especially with extended secondary treatment (10 min), enhanced hydrogel strength, uniformity, and extract entrapment efficiency (EE = 33% for P10). FT-IR and TGA indicated no chemical structural alterations post-treatment. Sequential thermal and HHP induction preserved polyphenol content, antioxidant activity (ABTS = 5.8 mg TE/g d.m.; DPPH = 11.1 mg TE/g d.m.), and reducing power (RP = 1.08 mg TE/g d.m.) due to the dense hydrogel structure effectively enclosing the elderberry extract. Sequential thermal and HHP induction was more effective in developing pea protein-psyllium hydrogels for elderberry extract entrapment.

Influence of High-Pressure Homogenization on the Physicochemical Properties and Betalain Pigments of Red Beetroot (Beta vulgaris L.) Juice.

High-pressure homogenization (HPH) is considered an innovative and modern method of processing and preserving liquid and semi-liquid foods. The aim of this research was to examine the impact of HPH processing on the content of betalain pigments and physicochemical properties of beetroot juice. Combinations of the following HPH parameters were tested: the pressure used (50, 100, 140 MPa), the number of cycles (1 and 3) and the applied cooling or no cooling. The physicochemical analysis of the obtained beetroot juices was based on the determination of the extract, acidity, turbidity, viscosity and color values. Use of higher pressures and a greater number of cycles reduces the turbidity (NTU) of the juice. Moreover, in order to maintain the highest possible extract content and a slight color change of the beetroot juice, it was crucial to perform sample cooling after the HPH process. The quantitative and qualitative profiles of betalains have been also determined in the juices. In terms of the content of betacyanins and betaxanthins, the highest values were found in untreated juice at 75.3 mg and 24.8 mg per 100 mL, respectively. The high-pressure homogenization process resulted in a decrease in the content of betacyanins in the range of 8.5-20.2% and of betaxanthins in the range of 6.5-15.0%, depending on the parameters used. Studies have shown that that the number of cycles was irrelevant, but an increase in pressure from 50 MPa to 100 or 140 MPa had a negative effect on pigment content. Additionally, juice cooling significantly limits the degradation of betalains in beetroot juice.

Application of Optical and Rheological Techniques in Quality and Storage Assessment of the Newly Developed Colloidal-Suspension Products: Yogurt-Type Bean-Based Beverages.

The objectives of this study were to compare the properties of the yogurt-type bean-based beverages B and BG produced from the nongerminated and germinated beans, respectively, by high-pressure homogenization (HPH) and fermentation with three starter cultures. Optical techniques were used to evaluate the particle size distribution (PSD), color parameters, and instability during storage, while rheological tests were used to evaluate the shear viscosity, flow behavior, and viscoelastic properties. The BG compared to B, irrespective of the starter culture used, showed a higher mean diameter and Span of PSD (d4,3 ≈ 76.8-84.2, Span ≈ 2.24-2.35 for BG vs. d4,3 ≈ 38.2-47.0, Span ≈ 1.90-2.00 for B). The BG vs. B showed lower viscosity (0.47 Pa·s for BG vs. 0.81 Pa·s for B at shear rate 75 s-1) and slightly lower but satisfactory stability (after 21 days at 6 °C, the Turbiscan Stability Index TSI ≈ 1.3-2.0 for BG vs. TSI ≈ 0.6-0.9 for B). Both B and BG were characterized by light-yellow color and showed the characteristics of a viscoelastic fluid. The HPH and germination mainly affected the properties of the tested plant tissue, which has a direct impact on the properties of the final products.

Characteristics of Dough Rheology and the Structural, Mechanical, and Sensory Properties of Sponge Cakes with Sweeteners.

Changes in the rheological properties of dough, as well as the microstructural, mechanical, and sensory properties of sponge cakes, as a function of the substitution of sucrose in a formulation with maltitol, erythritol, and trehalose are described. Moreover, the relationship between the examined properties was investigated. The replacement of sucrose with maltitol or trehalose did not affect the consistency index, whereas erythritol caused a decrease in its value. X-ray tomography was used to obtain the 2D and 3D microstructures of sponge cakes. All studied sweeteners caused the sponge cakes to have a typical porous structure. Erythritol and maltitol resulted in about 50% of the pores being smaller than 0.019 mm2 and 50% of the pores being larger than 0.032 mm2. Trehalose resulted in a homogeneous microstructure, 98% of whose pores were similar in size (0.019 to 0.032 mm2). The sponge cakes with polyols had a higher structure index than did the trehalose and sucrose samples. There were also significant differences in color parameters (lightness and chromaticity). The crust of the sponge cake with sweeteners was lighter and had a less saturated color than the crust of the sponge cake with sucrose. The sponge cake with maltitol was the most similar to the sponge cake with sucrose, mainly due to the mechanical and sensory properties. Trehalose led to the samples having high adhesiveness, which may limit its application as a sucrose substitute in sponge cake. Sensory properties were strongly correlated to cohesiveness, adhesiveness, and springiness and did not correlate to the 2D and 3D microstructures. It was found that 100% replacement of sucrose allows for a porous structure to be obtained. These results confirm that it is not the structure, but most of all the flavor, that determines the sensory perception of the sponge cakes.

Influence of Tea Brewing Parameters on the Antioxidant Potential of Infusions and Extracts Depending on the Degree of Processing of the Leaves of Camellia sinensis.

The polyphenol content of tea depends on the growing region, harvest date, the production process used, and the brewing parameters. In this study, research was undertaken that included an analysis of the influence of the brewing process parameters on the content of total polyphenols (Folin-Ciocalteu), epigallocatechin gallate (HPLC), and antioxidant activity (against DPPH radicals) of fresh tea shrub leaves grown from Taiwan and of teas obtained from them (oolong, green in bags, and green loose from the spring and autumn harvest). The antioxidant potential was determined in the methanol and aqueous extracts, as well as in infusions that were obtained by using water at 65 or 100 °C and infusing the tea for 5 or 10 min. The highest content of total polyphenols and epigallocatechin gallate was found in green tea extracts from the spring harvest. However, in the case of infusions, the highest content of these compounds was found in green tea in bags. Steaming at 100 °C for 10 min, turned out to be the most favourable condition for the extraction. Oolong tea, brewed at 100 °C for 5 min was characterised by the highest antioxidant activity against stable DPPH radicals.

Development of a High-Fibre Multigrain Bar Technology with the Addition of Curly Kale.

The aim of this study was to find the effect of kale and dietary fibre (DF) on the physicochemical properties, nutritional value and sensory quality of multigrain bars. A recipe of multigrain bars was prepared with the addition of fresh kale (20% and 30%) and DF preparations (apple, blackcurrant, chokeberry and hibiscus). The bars were baked at 180 °C for 20 min. These snack bars, based on pumpkin seeds, sunflower seeds, flaxseed and wholegrain oatmeal, are a high-calorie product (302-367 kcal/100 g). However, the composition of the bars encourages consumption. In addition to the ability to quickly satisfy hunger, such bars are rich in many natural ingredients that are considered pro-health (high fibre content (9.1-11.6 g/100 g), protein (11.2-14.3 g/100 g), fat (17.0-21.1 g/100 g, including unsaturated fatty acids), carbohydrates (20.5-24.0 g/100 g), as well as vitamins, minerals and a large number of substances from the antioxidant group. The addition of kale caused a significant increase of water content, but reduction in the value of all texture parameters (TPA profiles) as well as calorific values. The content of polyphenols was strongly and positively correlated with the antioxidant activity (r = 0.92). In the bars with 30% addition of kale (422 mg GA/100 g d.m.), the content of polyphenols was significantly higher than based ones (334 mg GA/100 g d.m.). Bars with the addition of the DF were characterized by a higher antioxidant activity, and the content of carotenoids, chlorophyll A and B and polyphenols. High sensory quality was demonstrated for all (from 4.8 to 7.1 on a 10-point scale). The addition of fibre preparations was also related to technological aspects and allows to create attractive bars without additional chemicals.

Edible coatings as osmotic dehydration pretreatment in nutrient-enhanced fruit or vegetable snacks development: A review.

Edible coatings (ECs) are thin layers applied on food to protect it and improve quality. They are made from bio-based materials such as polysaccharides, proteins, lipids, or their composites. The incorporation of functional agents, such as bioactive compounds, vitamins, or antimicrobials into the EC, has been investigated to control the shelf life of many food products from horticulture ones to processed food. Osmotic dehydration (OD) as a mild technology may also positively impact the availability of innovative fruit snacks and consequently influence consumer health. Combination of the EC with the OD aims to remove water through the semipermeable membrane while limiting the transfer of solutes from the dehydrated tissue and in the opposite direction from the osmotic solution to the food. The development trend of the snack market is expanding, especially with health-promoting properties. Consumers pay increasing attention to quality of food and its beneficial effects on health. This review attempts to provide the advancement of recent studies on the application of the EC before the OD of different fresh or fresh-cut fruit and vegetables. A fundamental theory related to the methodology of creating the EC, their composition, and the influence on the physicochemical properties of products that are osmo-dehydrated to a medium water content or additionally dried to a low water content have been described. Efforts have been exerted to introduce hydrocolloids used in the production of the EC, including new sources of biopolymers such as agricultural waste and by-products. The perspectives of using ECs in the technology of producing pro-healthy snacks are emphasized.

Influence of Pear Variety and Drying Methods on the Quality of Dried Fruit.

In this study, the impacts of two different pear cultivars, "Conference" and "Alexander Lucas", on the kinetics and the final quality of samples dried by convection (CD) and microwave-convection (MCD) methods, were investigated. The quality of dried material was evaluated by the analysis of water activity, porosity, color, acoustic emission (AE) and mechanical and sensory properties. The required drying time to obtain 0.2 kg H2O/kg dry solid (d.s.) was longer for "Conference" than "Alexander Lucas" and was 20 min by CD and 5 min by MCD. The pear cultivar, in conjunction with the drying method (CD or MCD), affected the number of AE events and the work of breaking. The CD pear of the "Conference" cultivar was characterized by higher force, higher breaking work and stronger AE relative to the CD pear of the "Alexander Lucas" cultivar. There were no differences in taste or overall quality, but the hardness was higher for the CD "Conference" pear. A principal component analysis showed that panelists preferred dried fruit with good taste and overall quality but lower hardness. A positive correlation was found between the number of acoustic events and sensory hardness; thus, an acoustic method can be useful for effectively evaluating the texture of dried pears. These results show that the dried pear slices that generated fewer AE events upon breaking were perceived as better by the panelists.

The Use of Antioxidant Potential of Chokeberry Juice in Creating Pro-Healthy Dried Apples by Hybrid (Convection-Microwave-Vacuum) Method.

The visible trend in the development of the snack market focuses on the use of innovative technologies such as low-temperature or hybrid processes that allow the preservation of native ingredients of raw plant materials. In addition, the high antioxidant potential of, for example, chokeberry fruit can be used to support technological processes and create new products. The aim of the study was to evaluate the possibility of using chokeberry juice concentrate as a component of an osmotic solution to enrich apple samples with natural bio-ingredients and obtain dried apples with increased content of ingredients with antioxidant properties; pro-healthy apple chips. The research material consisted of apples that underwent osmotic dehydration in solutions of sucrose or sucrose and chokeberry juice concentrate and then were dried by the freeze-drying or the hybrid method. The freeze-drying was more beneficial for maintaining the vitamin C content, while the use of the hybrid method resulted in the preservation of more polyphenolic compounds. The sensory evaluation indicated the need to modify the composition of the osmoactive solution. Due to the use of chokeberry juice concentrate, the content of vitamin C, polyphenols, and the antioxidant activity of dried apples was increased.

Physical and Sensory Properties of Japanese Quince Chips Obtained by Osmotic Dehydration in Fruit Juice Concentrates and Hybrid Drying.

Japanese quince has high health value, but due to its taste and texture, it is difficult to eat raw. The use of innovative drying methods to produce dried snack foods from these fruits may be of interest to producers and consumers. The physicochemical and sensory properties of 3 mm slices of Japanese quince fruit (with skin, without seeds) obtained by osmotic pre-treatment in chokeberry and apple juice concentrates, and with the use of convection (convective drying, C-D), freeze-drying (F-D), and convection-microwave-vacuum drying (hybrid) are assessed. The methods of drying osmo-dehydrated slices do not affect the dry matter content. In most dried quince, the water activity is 0.40 or lower. Pre-osmotic dehydration and drying have a significant impact on the mechanical and acoustic properties of quince chips. Sensory attractive chips emit loud acoustic emission (AE) during the breaking test. Chips that are osmo-dehydrated in a mixture of chokeberry juice concentrate and sucrose and dried by a hybrid method are attractive. They have a dark red color given by chokeberry concentrate and a slight sweet (with a slight sour-bitter) taste. The sensory evaluation was useful for determining the quality of the chips in terms of their texture (crispness) tested by mechanical methods. Their sensory ratings (overall desirability as weight of color, taste, crispness, and flavor) are high and similar (from 3.8 to 4.1). The use of innovative drying methods with pre-osmotic treatment allows obtaining dried material with properties comparable to those obtained by the F-D method, but in a much shorter time, i.e., with lower energy and using a simple method.

Neural Image Analysis and Electron Microscopy to Detect and Describe Selected Quality Factors of Fruit and Vegetable Spray-Dried Powders-Case Study: Chokeberry Powder.

The study concentrates on researching possibilities of using computer image analysis and neural modeling in order to assess selected quality discriminants of spray-dried chokeberry powder. The aim of the paper is the quality identification of chokeberry powders on account of their highest dying power, the highest bioactivity, as well as technologically satisfying looseness of the powder. The article presents neural models with vision techniques backed up by devices such as digital cameras, as well as an electron microscope. The reduction in size of input variables with PCA has an influence on improving the processes of learning data sets, thus increasing the effectiveness of identifying chokeberry fruit powders included in digital pictures, which is shown in the results of the conducted research. The effectiveness of image recognition is presented by classifying abilities, as well as low Root Mean Square Error (RMSE), for which the best results are achieved with a typology of network type Multi-Layer Perceptron (MLP). The selected networks type MLP are characterized by the highest degree of classification at 0.99 and RMSE at 0.11 at most at the same time.

Binary Pea Protein-Psyllium Hydrogel: Insights into the Influence of pH and Ionic Strength on the Physical Stability and Mechanical Characteristics.

Food hydrogels, used as delivery systems for bioactive compounds, can be formulated with various food-grade biopolymers. Their industrial utility is largely determined by their physicochemical properties. However, comprehensive data on the properties of pea protein-psyllium binary hydrogels under different pH and ionic strength conditions are limited. The aim of this research was to evaluate the impact of pH (adjusted to 7, 4.5, and 3) and ionic strength (modified by NaCl addition to 0.15 and 0.3 M) on the physical stability, color, texture, microrheological, and viscoelastic properties of these hydrogels. Color differences were most noticeable at lower pH levels. Inducing hydrogels at pH 7 (with or without NaCl) and pH 4.5 and 3 (without NaCl) resulted in complete gel structures with low stability, low elastic and storage moduli, and low complex viscosity, making them easily spreadable. Lower pH inductions (4.5 and 3) in the absence of NaCl resulted in hydrogels with shorter linear viscoelastic regions. Hydrogels induced at pH 4.5 and 3 with NaCl had high structural stability, high G' and G" moduli, complex viscosity, and high spreadability. Among the tested induction conditions, pH 3 with 0.3 M NaCl allowed for obtaining a hydrogel with the highest elastic and storage moduli values. Adjusting pH and ionic strength during hydrogel induction allows for modifying and tailoring their properties for specific industrial applications.

The Effect of Pre-Treatment (Blanching, Ultrasound and Freezing) on Quality of Freeze-Dried Red Beets.

This paper presents the influence of blanching, ultrasonic processing and freezing conditions on selected physical properties of freeze-dried red beet, i.e., water activity, structure, porosity and shrinkage. Red beets subjected to a selected pre-treatment using its various parameters were frozen by three methods and then freeze-dried. Ultrasound reduced the water activity of samples. Blanching in water reduced shrinkage and improved porosity. In addition to the type of pre-treatment applied, the quality was also affected by freezing conditions before drying. Combined freezing resulted in the highest shrinkage and the lowest porosity and water activity. Slowly frozen samples were characterized by the best porosity.

Tapioca Dextrin as an Alternative Carrier in the Spray Drying of Fruit Juices-A Case Study of Chokeberry Powder.

This paper analyses the semi-industrial process of spray drying chokeberry juice with carbohydrate polymers used as a carrier. Tapioca dextrin (Dx) was proposed and tested as an alternative carrier and it was compared with maltodextrin carriers (MDx), which are the most common in industrial practice. The influence of selected process parameters (carrier type and content, inlet air temperature, atomiser speed) on the characteristics of dried chokeberry powder was investigated. The size and microstructure of the powder particles, the bulk and apparent density, porosity, flowability, yield and bioactive properties were analysed. In comparison with MDx, the Dx carrier improved the handling properties, yield and bioactive properties. An increase in the Dx carrier content improved the phenolic content, antioxidant capacity, flowability and resulted in greater yield of the powder. An increase in the drying temperature increased the size of particles and improved powder flowability but it also caused a greater loss of the phenolic content and antioxidant capacity. The rotary atomizer speed had the most significant effect on the bioactive properties of obtained powders, which increased along with its growth. The following conditions were the most favourable for chokeberry juice with tapioca dextrin (Dx) as the carrier: inlet air temperature, 160 °C; rotary atomizer speed, 15,000 rpm; and Dx carrier content, 60%.