Comparison of spray drying, freeze drying and convective hot air drying for the production of a probiotic orange powder

Multistimuli responsive microcapsules produced by the prilling/vibration technique for targeted colonic delivery of probiotics

This study aimed to microencapsulate the probiotic strain Lactiplantibacillus plantarum 4S6R (basonym Lactobacillus plantarum) in both microcapsules and microspheres by prilling/vibration technique. A specific polymeric mixture, selected for its responsiveness to parallel colonic stimuli, was individuated as a carrier of microparticles. Although the microspheres were consistent with some critical quality parameters, they showed a low encapsulation efficiency and were discarded. The microcapsules produced demonstrated high yields (97.52%) and encapsulation efficiencies (90.06%), with dimensional analysis and SEM studies confirming the desired size morphology and structure. The results of thermal stress tests indicate the ability of the microcapsules to protect the probiotic. Stability studies showed a significant advantage of the microcapsules over non-encapsulated probiotics, with greater stability over time. The release study under simulated gastrointestinal conditions demonstrated the ability of the microcapsules to protect the probiotics from gastric acid and bile salts, ensuring their viability. Examination in a simulated faecal medium revealed the ability of the microcapsules to release the bacteria into the colon, enhancing their beneficial impact on gut health. This research suggests that the selected mixture of reactive polymers holds promise for improving the survival and efficacy of probiotics in the gastrointestinal tract, paving the way for the development of advanced probiotic products.

Freeze-drying revolution: unleashing the potential of lyophilization in advancing drug delivery systems

Lyophilization also known as freeze-drying is a technique that has been employed to enhance the long-term durability of nanoparticles (NPs) that are utilized for drug delivery applications. This method is used to prevent their instability in suspension. However, this dehydration process can cause stress to the NPs, which can be alleviated by the incorporation of excipients like cryoprotectants and lyoprotectants. Nevertheless, the freeze-drying of NPs is often based on empirical principles without considering the physical-chemical properties of the formulations and the engineering principles of freeze-drying. For this reason, it is crucial to optimize the formulations and the freeze-drying cycle to obtain a good lyophilizate and ensure the preservation of NPs stability. Moreover, proper characterization of the lyophilizate and NPs is of utmost importance in achieving these goals. This review aims to update the recent advancements, including innovative formulations and novel approaches, contributing to the progress in this field, to obtain the maximum stability of formulations. Additionally, we critically analyze the limitations of lyophilization and discuss potential future directions. It addresses the challenges faced by researchers and suggests avenues for further research to overcome these limitations. In conclusion, this review is a valuable contribution to the understanding of the parameters involved in the freeze-drying of NPs. It will definitely aid future studies in obtaining lyophilized NPs with good quality and enhanced drug delivery and therapeutic benefits.

Oral delivery of probiotics using single-cell encapsulation

Adequate intake of live probiotics is beneficial to human health and wellbeing because they can help treat or prevent a variety of health conditions. However, the viability of probiotics is reduced by the harsh environments they experience during passage through the human gastrointestinal tract (GIT). Consequently, the oral delivery of viable probiotics is a significant challenge. Probiotic encapsulation provides a potential solution to this problem. However, the production methods used to create conventional encapsulation technologies often damage probiotics. Moreover, the delivery systems produced often do not have the required physicochemical attributes or robustness for food applications. Single-cell encapsulation is based on forming a protective coating around a single probiotic cell. These coatings may be biofilms or biopolymer layers designed to protect the probiotic from the harsh gastrointestinal environment, enhance their colonization, and introduce additional beneficial functions. This article reviews the factors affecting the oral delivery of probiotics, analyses the shortcomings of existing encapsulation technologies, and highlights the potential advantages of single-cell encapsulation. It also reviews the various approaches available for single-cell encapsulation of probiotics, including their implementation and the characteristics of the delivery systems they produce. In addition, the mechanisms by which single-cell encapsulation can improve the oral bioavailability and health benefits of probiotics are described. Moreover, the benefits, limitations, and safety issues of probiotic single-cell encapsulation technology for applications in food and beverages are analyzed. Finally, future directions and potential challenges to the widespread adoption of single-cell encapsulation of probiotics are highlighted.

Viability of Lactobacillus acidophilus in Thin-Film Freeze-Dried Powders Filled in Delayed-Release Vegetarian Capsules in a Simulated Gastric Fluid

Previously, we have shown that thin-film freeze-drying can be applied to prepare dry powders of bacteria such as Lactobacillus acidophilus. Herein, we tested the viability of L. acidophilus in thin-film freeze-dried powders (TFF powders) filled in delayed-release vegetarian capsules in a simulated gastric fluid (SGF) consisting of 0.1N hydrochloric acid and sodium chloride. Initially, we determined the water removal rate from frozen thin films on relatively larger scales (i.e., 10-750 g). We then prepared and characterized two TFF powders of L. acidophilus with either sucrose and maltodextrin or sucrose and hydroxypropyl methylcellulose acetate succinate (HPMC-AS), a pH-sensitive polymer, as excipients and evaluated the viability of the bacteria after the TFF powders were filled in delayed-release vegetarian capsules and the capsules were incubated in the SGF for 30 min. On 10-750 g scales and at the settings specified, water removal from frozen thin films was faster than from slow shelf-frozen bulk solids. When the L. acidophilus in sucrose and HPMC-AS TFF powder was filled into a delayed-release capsule that was placed into another delayed-release capsule, the bacterial viability reduction after incubation in the SGF can be minimized to within 1 log in colony forming unit (CFU). However, for the L. acidophilus in sucrose and maltodextrin TFF powder, even in the capsule-in-capsule dosage form, bacterial CFU reduction was > 2 logs. TFF powders of live microorganisms containing an acid-resistant material in capsule-in-capsule delayed-release vegetarian capsules have the potential for oral delivery of those microorganisms.

Comparative Analysis of Concurrent (CC), Mixed Flow (MX), and Combined Spray Drying Configurations on the Physicochemical Characteristics of Satsuma Mandarin (Citrus unshiu) Juice Powders

Satsuma mandarins are good sources of vitamin C and can be used as raw materials to produce novel plant-based food ingredients including satsuma mandarin juice powders (SJP). Food powders produced via spray drying often show thermal degradation due to the drying conditions and high drying air temperatures. The aim of this study was to evaluate the effect of using different spray drying configurations, including concurrent (CC), mixed flow (MX), and combined (CC + MX), at two inlet air temperatures (160 and 180 °C) on the physicochemical properties of SJP. Remarkably, SJP produced using the CC spray drying configuration exhibited a higher vitamin C content (3.56-4.01 mg/g) and lower moisture levels (15.18-16.35 g/100 g) than powders produced via MX or CC + MX. The vitamin C content of MX and CC + MX powders ranged from 2.88 to 3.33 mg/g. Meanwhile, all SJP had water activity values below 0.19. Furthermore, MX powders displayed the largest mean particle sizes (D50) (8.69-8.83 µm), higher agglomeration, and a rapid dissolution. Despite these differences, all SJP variants exhibited consistent color, surface area, and pore volumes. Notably, powders dried at higher inlet air temperatures (180 °C) showed less vitamin C content and increased thermal damage when compared with powders dried at 160 °C inlet air temperature. This study demonstrated the feasibility of producing high-quality SJP with an extended shelf life. SJP can be used as a novel plant-based ingredient in different food applications.

Encapsulation of betalain-rich extract from beetroot postharvest waste using a binary blend of gum Arabic and maltodextrin to promote a food circular bioeconomy

Introduction

The present study evaluated the potential of maltodextrin (MT), gum Arabic (GA), and their blends to produce functional beetroot waste extract powder (BWEP).

Methods

The beetroot waste extracts were produced using 50% ethanol and encapsulated using 10% (1:10, w/v) of the GA and MT carriers at different blending ratios, namely, GA:MT 1:0, GA:MT 0:1, GA:MT 1:1, GA:MT 2:1, and GA:MT 1:2, respectively. The BWEP were analyzed for physicochemical, technofunctional, morphological, crystallinity, and antioxidant properties.

Results

BWEP produced using either GA or MT exhibited better color, solubility, encapsulation efficiency, and betalain content. Powders from the blends of GA and MT showed better oil holding capacity and total phenolic content. On the other hand, powder yield, total soluble solids, titratable acidity, bulk density, and DPPH radical scavenging activity did not significantly differ (p > 0.05) among the powders. BWEP produced using GA and MT separately was relatively smaller and more regular compared to the powders from the blended biopolymers. All powders showed signs of agglomeration, which was more pronounced in the powders from the blended biopolymers. A total of 16 metabolites, including betalains (9), phenolic acids (2), and flavonoids (5), were tentatively identified. The majority of the metabolites were entrapped in the BWEP produced using GA and MT separately. The quantified metabolites included gallic acid (33.62-44.83 μg/g DM), (+)-catechin (32.82-35.84 μg/g DM), (-)-epicatechin (37.78-45.89 μg/g DM), and myricetin (30.07-35.84 μg/g DM), which were significantly higher in the BWEP produced from GA or MT separately.

Discussion

The study showed that although blending GA and MT has the potential to improve the quality of BWEP, using these biopolymers separately showed a promise to promote a food circular bioeconomy.

Comparison of Electrostatic Spray Drying, Spray Drying, and Freeze Drying for Lacticaseibacillus rhamnosus GG Dehydration

Spray drying (SD) is extensively used to encapsulate lactic acid bacteria in large-scale industrial applications; however, bacteria combat several harms that reduce their viability. In this study, a novel technique called electrostatic spray drying (ESD) was used to explore the benefits and disadvantages of using electrostatic charge and lower temperatures in the system. Freeze drying (FD) was used as a reference. The effect of different encapsulation agents, like maltodextrin, arabic gum, and skim milk, on the viability of Lacticaseibacillus rhamnosus GG (LGG) was investigated. The initial cell concentration, particle size distribution, aspect ratio, sphericity, scanning-electron-microscopy images, moisture content, water activity, glass transition, rehydration abilities, and survival during storage were compared. Skim milk was proven to be the best protectant for LGG, regardless of the drying process or storage time. A huge reduction in cell numbers (4.49 ± 0.06 log CFU/g) was observed with maltodextrin using SD; meanwhile, it was protected with minimum loss (8.64 ± 0.62 log CFU/g) with ESD. In general, ESD preserved more LGG cells during processing compared to SD, and provided better stability than FD and SD during storage, regardless of the applied voltage. The ESD product analysis demonstrated an efficient LGG preservation, close to FD; therefore, ESD presented to be a promising and scalable substitute for SD and FD.

Tackling the challenge of drying and redispersion of cellulose nanofibrils via membrane-facilitated liquid phase exchange

It is generally acknowledged that to advance the application of cellulose nanofibrils (CNFs) in product formulations, challenges associated with the drying and redispersion of this material must be addressed. Despite increased research efforts in this area, these interventions still involve the use of additives or conventional drying technologies, which both have the capacity to drive up the cost of the final CNF powders. Herein, we prepared dried and redispersible CNF powders with varying surface functionalities without the use of additives nor conventional drying technologies. Rapid drying in air was achieved after liquid phase exchange from water to isopropyl alcohol. The surface properties, morphology and thermal stabilities were the same for the never-dried and redispersed forms. The rheological properties of the CNFs were also unaffected after drying and redispersion of unmodified and organic acid modified materials. However, for 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-mediated oxidised CNFs with higher surface charge and longer fibrils, the storage modulus could not be recovered to the never-dried state because of the possible non-selective reduction in length upon redispersion. Nevertheless, this method provides an effective and low-cost process for the drying and redispersion of unmodified and surface modified CNFs.

Impact of Processing and Physicochemical Parameter on Hibiscus sabdariffa Calyxes Biomolecules and Antioxidant Activity: From Powder Production to Reconstitution

Hibiscus sabdariffa is a tropical plant with red calyxes whose anthocyanins, phenols, and antioxidant activity make it attractive to consumers both from a nutritional and medicinal standpoint. Its seasonality, perishability, and anthocyanin instability, led to the setup of stabilization methods comprising drying and powdering. However, its properties can often be altered during these stabilization processes. Treatments such as dehumidified-air-drying, infrared drying, and oven-drying, and their combination showed better quality preservation. Moreover, powder production enables superior biomolecule extractability which can be linked to a higher bioaccessibility. However, the required temperatures for powder production increase the bioactive molecules degradation leading to their antioxidant activity loss. To overcome this issue, ambient or cryogenic grinding could be an excellent method to improve the biomolecule bioavailability and accessibility if the processing steps are well mastered. To be sure to benefit from the final nutritional quality of the powder, such as the antioxidant activity of biomolecules, powders have to offer excellent reconstitutability which is linked to powder physicochemical properties and the reconstitution media. Typically, the finest powder granulometry and using an agitated low-temperature reconstitution media allow for improving anthocyanin extractability and stability. In this review, the relevant physicochemical and processing parameters influencing plant powder features from processing transformation to reconstitution will be presented with a focus on bioactive molecules and antioxidant activity preservation.

Assessment of drying conditions for storage of a yeast-based decolorization solution for application in textile industrial wastewater treatment plants

The textile industry produces harmful effluents that are discharged into the environment, damaging the aquatic and other ecosystems. A yeast-based solution for decolorization of textile industrial wastewater was produced and evaluated. Three yeast strains, Candida parapsilosis (HOMOGS20B), Yarrowia lipolytica (HOMOGST27AB) and Candida pseudoglaebosa (LIIIS36B), isolated from a textile wastewater treatment plant and previously selected for their dye decolorization capacity, were freeze-dried. Additionally, Yarrowia lipolytica (HOMOGST27AB) was also spray-dried. Skim milk powder and maltodextrin were used as cell protectors, and the freeze-dried products were stored at cold (4 °C) and room temperature for 210 days. The viability of the yeast cells and their decolorization capacity over time were assessed. Dried yeast cells maintained their viability, and decolorization capacity for at least 90 days of storage after spray- and freeze-drying with both cell-protecting agents. The dried yeast-based solution for decolorizing textile industrial wastewater combines stability, efficiency, and convenience of production for application in real industrial facilities.

Effects of emerging food pretreatment and drying techniques on protein structures, functional and nutritional properties: An updated review

Protein is one of the most important components of food which significantly contributes to the structure, functionality, and sensory properties which may affect consumer acceptability of processed products. Conventional thermal processing affects protein structure and induce undesirable degradation of food quality. This review provides an overview of emerging pretreatment and drying technologies (plasma treatment, ultrasound treatment, electrohydrodynamic, radio frequency, microwave, and superheated steam drying) in food processing by assessing protein structural changes to enhance functional and nutritional properties. In addition, mechanisms and principles of these modern technologies are described while challenges and opportunities for the development of these techniques in the drying process are also critically analyzed. Plasma discharges can lead to oxidative reactions and cross-linking of proteins that can change the structure of proteins. Microwave heating contributes to the occurrence of isopeptide or disulfide bonds which promotes α-helix and β-turn formation. These emerging technologies can be adopted to improve protein surface by exposing more hydrophobic groups which restrict water interaction. It is expected that these innovative processing technologies should become a preferred choice in the food industry for better food quality. Moreover, there are some limitations for industrial scale application of these emerging technologies that need to be addressed.

Comparative Analysis of the Impact of Three Drying Methods on the Properties of Citrus reticulata Blanco cv. Dahongpao Powder and Solid Drinks

Citrus reticulata Blanco cv. Dahongpao is a traditional Chinese citrus variety. Due to the high investment in storage and transport of Citrus reticulata Blanco cv. Dahongpao and the lack of market demand, the fresh fruit is wasted. The processing of fresh fruit into fruit drinks can solve the problem of storage and transport difficulties and open up new markets. Investigating the effects of different drying processes (hot air, freeze, and spray drying) on fruit powders is a crucial step in identifying a suitable production process. The experiment measured the effects of different drying methods (hot air drying, freeze drying, and spray drying) on the nutrient, bioactive substance, and physical characteristics of fruit powder. This study measured the influence of three different drying methods (hot air, freeze, and spray drying) on the nutritional, bioactive substance, and physical characteristics of fruit powder. The results showed that compared to vacuum freeze-drying at low temperature (-60 °C) and spray-drying at high temperatures (150 °C), hot air drying at 50 °C produced fruit powder with superior nutritional quality, higher levels of active substances, and better physical properties. Hot air drying produced fruit powder that had the highest content of amino acids (11.48 ± 0.08 mg/g DW), vitamin C (112.09 ± 2.86 μg/g DW), total phenols (14.78 ± 0.30 mg/g GAE DW), total flavonoids (6.45 ± 0.11 mg/g RE DW), organic acids, and antioxidant activity capacity. Additionally, this method yielded the highest amounts of zinc (8.88 ± 0.03 mg/Kg DW) and soluble sugars, low water content, high solubility, and brown coloration of the fruit powder and juice. Therefore, hot air drying is one of the best production methods for producing high-quality fruit powder in factory production.

Optimization of spray dried yogurt and its application to prepare functional cookies

Introduction

Spray-dried yogurt powder (SDYP) has shelf stability and other functional properties that improve solubility and facilitate the use, processing, packaging, and transportation of other food derivatives, such as bread and pastries on a large scale. The present research was conducted to develop SDYP and further its utilization to prepare functional cookies.

Methods

Yogurt was spray-dried by employing different outlet air temperatures (OAT) (65°C, 70°C & 75°C) and inlet air temperature (IAT) (150°C, 155°C & 160°C). Spray drying shows that increasing the temperature increases nutritional loss, whereas S. thermophilus culture shows resistance to the intensive heat approaches. On the other hand L. delbrueckii subsp. Bulgaricus culture was found to be significantly affected. A total of 4 treatments, including one control for the functional cookies development.

Results and discussion

A directly proportional relation was investigated between the increasing concentration of SDYP and baking characteristics and cookie's mineral and protein profile. Bioactive parameters like antioxidant activity of 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and total phenolic content (TPC) were also affected significantly. The sensory profile shows an incline towards T0 (0% SDYP) to T3 (10% SDYP) in all attributes but starts to decline when the concentration of SDYP reaches 15%. This study suggests that by employing a certain combination of temperatures (OAT: 60°C IAT: 150°C); maximum survival of inoculated culture can be achieved, and this powder can be utilized in the development of functional cookies with enhanced sensory as well as biochemical characteristics significantly (P< 0.05).

Improved infectious burn wound healing by applying lyophilized particles containing probiotics and prebiotics

Lactiplantibacillus plantarum cells were encapsulated in a mixture of cationic and anionic polymers, with the final composition stabilized through freeze-drying. A D-optimal design was used to examine the effects of different polymer concentrations as well as adding prebiotics on the probiotic viability and swelling behavior of the formulations. Scanning electron micrographs revealed stacked particles capable of rapidly absorbing significant amounts of water. These images corresponded to initial swelling percentages of around 2000% for the optimal formulation. The optimized formula had a viability percentage of more than 82%, with the stability studies suggesting that the powders should be stored at refrigerated temperatures. The physical characteristics of the optimized formula were examined to ensure compatibility with its application. According to antimicrobial evaluations, the difference in pathogen inhibition between formulated and fresh probiotics was less than a logarithm. The final formula was tested in vivo and showed improved wound healing indicators. The optimized formula resulted in a higher rate of wound closure and infection clearance. Furthermore, the molecular studies for oxidative stress indicated that the formula could modify wound inflammatory responses. In histological investigations, the probiotic-loaded particles functioned exactly as efficaciously as silver sulfadiazine ointment did.

Microencapsulation with Different Starch-Based Polymers for Improving Oxidative Stability of Cold-Pressed Hickory (Carya cathayensis Sarg.) Oil

Hickory (Carya cathayensis Sarg.) oil is a nutrient-dense edible woody oil, with its unsaturated fatty acids accounting for more than 90% of total ones, and liable to oxidation spoilage. To efficiently improve its stability and expand its application fields, the microencapsulation of cold-pressed hickory oil (CHO) by the molecular embedding method and freeze-drying technique was performed using malt dextrin (MD), hydroxylpropyl-β-cyclodextrin (HP-β-CD), β-cyclodextrin (β-CD), or porous starch (PS) as a wall material. Two wall materials and/or their CHO microcapsulates (CHOM) with higher encapsulation efficiencies (EE) were selected to carry out physical and chemical characterizations using laser particle size diffractometer, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, derivative thermogravimetry, and oxidative stability tests. Results indicated β-CDCHOM and PSCHOM had significantly higher EE values (80.40% and 75.52%) than MDCHOM and HP-β-CDCHOM (39.36% and 48.32%). The particle sizes of the two microcapsules selected were both widely distributed with their spans being more than 1 µm and a certain degree of polydispersity. Microstructural and chemical characterizations indicated that β-CDCHOM had comparatively stable structure and good thermal stability compared with PSCHOM. Storage performances under light, oxygen, and temperature showed that β-CDCHOM was superior to PSCHOM, especially in terms of thermal and oxidative stability. This study demonstrates that β-CD embedding can be applied to improve the oxidative stability of vegetable oils such as hickory oil and act as a means of preparing functional supplementary material.

Freeze-Drying Microencapsulation of Hop Extract: Effect of Carrier Composition on Physical, Techno-Functional, and Stability Properties

In this study, freeze-drying microencapsulation was proposed as a technology for the production of powdered hop extracts with high stability intended as additives/ingredients in innovative formulated food products. The effects of different carriers (maltodextrin, Arabic gum, and their mixture in 1:1 w/w ratio) on the physical and techno-functional properties, bitter acids content, yield and polyphenols encapsulation efficiency of the powders were assessed. Additionally, the powders' stability was evaluated for 35 days at different temperatures and compared with that of non-encapsulated extract. Coating materials influenced the moisture content, water activity, colour, flowability, microstructure, and water sorption behaviour of the microencapsulates, but not their solubility. Among the different carriers, maltodextrin showed the lowest polyphenol load yield and bitter acid content after processing but the highest encapsulation efficiency and protection of hop extracts' antioxidant compounds during storage. Irrespective of the encapsulating agent, microencapsulation did not hinder the loss of bitter acids during storage. The results of this study demonstrate the feasibility of freeze-drying encapsulation in the development of functional ingredients, offering new perspectives for hop applications in the food and non-food sectors.

Spray Drying Encapsulation of Pediococcus acidilactici at Different Inlet Air Temperatures and Wall Material Ratios

Pediococcus acidilactici has gained research and commercial interest due to its outstanding probiotic properties, yet its survival during storage and consumption requires improvement. This study aims to enhance P. acidilactici survival using spray drying encapsulation. Different inlet air temperatures (120 °C, 150 °C, and 170 °C) and whey protein isolate (WPI):gum arabic (GA) ratios (1:1, 3:1, 1:3) were tested. Cell viability was significantly (p < 0.05) affected by the inlet temperature but not the WPI:GA ratio. Increasing the inlet temperature to 170 °C significantly decreased P. acidilactici viability by 1.36 log cycles, from 8.61 log CFU/g to 7.25 log CFU/g. The inlet temperature of 150 °C resulted in a powder yield (63.12%) higher than at 120 °C (58.97%), as well as significantly (p < 0.05) lower moisture content (5.71%) and water activity (aw 0.21). Viable cell counts in all encapsulated P. acidilactici were maintained at 5.24−6.75 log CFU/g after gastrointestinal tract (GIT) simulation, with WPI:GA of 3:1 and inlet temperature 150 °C having the smallest log reduction (0.3 log cycles). All samples containing different WPI:GA ratios maintained sufficient viability (>7 log CFU/g) during the first three weeks of storage at 25 °C. These results could provide insights for further developing P. acidilactici as commercial probiotic products.

Optimization of spray drying process parameters for the food bioactive ingredients

Spray drying (SD) is one of the most important thermal processes used to produce different powders and encapsulated materials. During this process, quality degradation might happen. The main objective of applying optimization methods in SD processes is maximizing the final nutritional quality of the product besides sensory attributes. Optimization regarding economic issues might be also performed. Applying optimization approaches in line with mathematical models to predict product changes during thermal processes such as SD can be a promising method to enhance the quality of final products. In this review, the application of the response surface methodology (RSM), as the most widely used approach, is introduced along with other optimization techniques such as factorial, Taguchi, and some artificial intelligence-based methods like artificial neural networks (ANN), genetic algorithms (GA), Fuzzy logic, and adaptive neuro-fuzzy inference system (ANFIS). Also, probabilistic methods such as Monte Carlo are briefly introduced. Some recent case studies regarding the implementation of these methods in SD processes are also exemplified and discussed.

Exploring Freeze-Drying as Strategy to Enhance Viability of Faecalibacterium duncaniae DSM 17677 upon Aerobic Storage and Gastrointestinal Conditions

Faecalibacterium duncaniae is an intestinal commensal bacterium proposed as a next-generation probiotic due to its promising outcomes in the treatment and prevention of several human diseases, which demonstrate its multiple contributions to the host’s health. However, its strict anaerobic nature has created several hurdles in the development of functional foods, nutraceuticals, and biotherapeutic products. Herein, we explored freeze-dried formulations containing prebiotics, cryoprotectants, and antioxidant agents as a technological strategy to enhance the viability of F. duncaniae DSM 17677 upon aerobic storage and gastrointestinal tract conditions. Our results indicate that freeze-dried F. duncaniae in a matrix containing inulin, sucrose, cysteine, and riboflavin survived at levels higher than 106 CFU/g and around 105 CFU/g after 1 and 4 days of aerobic storage at room temperature, respectively. Thus, the freeze-dried formulation with inulin, sucrose, cysteine, and riboflavin presents as a protective strategy to improve F. duncaniae viability under aerobic environments. Nevertheless, incorporation of a suitable coating aimed at protecting F. duncaniae against the detrimental gastrointestinal passage effects is urgently required, given its high susceptibility to extreme acidic pH values and bile.

Microencapsulation of Lactobacillus plantarum LN66 and its survival potential under different packaging conditions

Microcapsules of Lactobacillus plantarum LN66 were prepared to improve the cell viability in simulated gastrointestinal and different packaging conditions. Microcapsules containing Lactobacillus plantarum LN66 were produced by complex coacervation followed by freeze drying and characterised by water activity, moisture content, size, encapsulation efficiency, SEM, FTIR, XRD, as well as the resistance of probiotics to the simulated gastrointestinal tract and storage under different packaging conditions. The microcapsules presented the particle size of 196.57 ± 1.46 μm and the encapsulation efficiency of 75.26 ± 1.95% (w/w). After simulated gastrointestinal conditions, viability of encapsulated cells was 71.33 ± 0.99% (w/w) and 70.39 ± 0.86% (w/w), separately, while that of free cells was only 45.45 ± 0.5% (w/w) and 8.59 ± 0.67% (w/w). Compared with aluminium foil, the viable cells in glass bottles at 4 °C and 25 °C was increased 1.1-fold and 1.4-fold, respectively. Complex coacervation could be considered an appropriate alternative to increase the viability of probiotics.

Impact of hydrocolloid and foaming agent on the physicochemical, microstructural and bioactive characteristics of foam-mat freeze-dried tapai (fermented black glutinous rice) powder

The aim of this study was to obtain fermented black glutinous rice (FBGR) powder using the foam-mat freeze-drying method and to evaluate the physicochemical, microstructural, and bioactive characteristics of FBGR powder. To obtain FBGR foams, maltodextrin (MD; 0%-40% w/w) and whey protein isolate (WPI; 7.5% w/w) were used. The results showed that MD concentration had a significant effect (p ≤ .05) on powder recovery and bulk density which increased from 68.9% to 80.5% and 0.46% to 0.63 g/ml, respectively. The lowest moisture content (2.17%) and water activity (0.48) were found in powders produced with 20% MD. The solubility of FBGR powders ranged from 74% to 75% and increasing MD concentration gave higher lightness (L*) and yellowness (b*) readings in color properties of powders. Although the addition of the carrier agent caused reductions in total phenolic content and anthocyanins, the retention of these bioactive compounds rose with increasing MD content from 67% to 76% and 78% to 84%, respectively. FBGR produced with 40% MD had the most superior physical and technological properties, and foam-mat freeze-drying is a promising technology for retaining the bioactive compounds in FBGR.

Micro-Encapsulation of Phytochemicals in Passion Fruit Peel Waste Generated on an Organic Farm: Effect of Carriers on the Quality of Encapsulated Powders and Potential for Value-Addition

The passion (Passiflora edulis Sims) fruit peel is rich in phenolics and other bioactive compounds and has great potential as a natural food preservative. The present study investigated the value-adding potential of passion fruit peel waste generated on an organic farm. The effect of carriers in encapsulating the peel extract to develop a polyphenolic-rich powder was investigated. The passion fruit peel extracts were prepared using 70% ethanol (1:10 w/v), and encapsulated using waxy starch (WS), gum arabic (GA), and maltodextrin (MT) before freeze-drying. The effects of carriers on the passion fruit peel powder (PFPP) production yield, physicochemical, rheological, phytochemical, and antioxidant properties were investigated. GA-and MT-encapsulated powders had better physical, phytochemical, and antioxidant properties, including yield, total soluble solids, solubility, bulk density, total phenolic content, and ferric reducing antioxidant powder. A total of 18 metabolites, including phenolic acids (10), flavonoids (6), and stilbenes (2), were tentatively identified in all the PFPP samples, with WS exhibiting a higher concentration of the compounds compared to GA and MT. Our results indicated that no single carrier was associated with all the quality attributes; therefore, better results could be produced by compositing these carriers. Nonetheless, our results highlight the potential of passion fruit peels as a source of polyphenols and functional ingredient in formulating natural food additives.

Current Trends in the Production of Probiotic Formulations

Preparations containing probiotic strains of bacteria have a beneficial effect on human and animal health. The benefits of probiotics translate into an increased interest in techniques for the preservation of microorganisms. This review compares different drying methods and their improvements, with specific reference to processing conditions, microorganisms, and protective substances. It also highlights some factors that may influence the quality and stability of the final probiotic preparations, including thermal, osmotic, oxidative, and acidic stresses, as well as dehydration and shear forces. Processing and storage result in the loss of viability and stability in probiotic formulations. Herein, the addition of protective substances, the optimization of process parameters, and the adaptation of cells to stress factors before drying are described as countermeasures to these challenges. The latest trends and developments in the fields of drying technologies and probiotic production are also discussed. These developments include novel application methods, controlled release, the use of food matrices, and the use of analytical methods to determine the viability of probiotic bacteria.

Impact of Different Drying Methods on the Acerola-Ceriguela Mixed Pulp: Physicochemical Characteristics, Bioactive Compounds, and Sensory Attributes

Fruit mixed pulp has the objective of improving the nutritional and sensorial characteristics, as well as the development of new flavours and aromas. Different methods of drying (e.g., spray-drying, spouted bed drying, and freeze-drying) can influence the quality of the final product. The objective of this study was to select the drying method that enables the production of acerola-ceriguela mixed pulp (ACMP) with higher quality. For this selection, the powder pulps were evaluated for their physicochemical characteristics (water activity, moisture, soluble solids (SS), titratable acidity (TA), SS/TA, and instrumental colour), retention of the bioactive compounds (ascorbic acid, total carotenoids, and phenolic compounds), and sensory evaluation (acceptance, check-all-that-apply (CATA), and intent to purchase). The physicochemical characteristics of the freeze-dried and spray-dried ACMP were nonsignificant $\left(p>0.05\right)$ but differed significantly $\left(p>0.05\right)$ from spouted bed powder. ACMP freeze-drying powder resulted in higher retention of ascorbic acid, total carotenoids, and phenolic compounds. The powder obtained by spray-drying showed higher retention of bioactive compounds compared to the spouted bed drying. Therefore, this study suggests that powder obtained by freeze-drying resulted in greater sensorial acceptance.

Sequential Membrane Filtration to Recover Polyphenols and Organic Acids from Red Wine Lees: The Antioxidant Properties of the Spray-Dried Concentrate

The vinification process produces a considerable amount of waste. Wine lees are the second most generated byproduct, representing around 14% of total vinification wastes. They are a valuable source of natural antioxidants, mainly polyphenols, as well as organic acids, such as tartaric acid. This paper deals with the application of an integrated, environment friendly membrane separation process to recover polyphenols and organic acids. A two-step membrane process is described, consisting of an ultra- and a nano-filtration process. The physicochemical and antioxidant properties of all the process streams were determined. High Pressure Liquid Chromatography (HPLC) was employed for identifying certain individual organic acids and polyphenols, while the antioxidant potential was determined by the 2,2′-diphenyl-1-picrylhydrazyl radical) (DPPH) radical scavenging ability and ferric reducing ability. A liquid concentrate stream containing 1351 ppm of polyphenols was produced and then spray dried. The resulting powder retained most of the polyphenols and antioxidant properties and was successfully applied to a real food system to retard lipid oxidation, followed by Thiobarbituric Acid Reactive Substances (TBARS) and the determination of oxymyoglobin content. The results show that membrane separation technology is an attractive alternative process for recovering value-added ingredients from wine lees.

Effects of Spray-Drying and Freeze-Drying on Bioactive and Volatile Compounds of Smoke Powder Food Flavouring

Transforming liquid smoke to powder form can provide convenience for use and storage. Liquid smoke was prepared by fast pyrolysis technology using a fluidised bed and converted to smoke powder by spray-drying or freeze-drying processes. Both drying processes effectively retained the bioactive compounds in the powder encapsulates with retention efficiencies up to 80%. The bioactive capacities were approximately two times higher than liquid smoke. Spray-drying did not induce thermal damage to the bioactive compounds, and the dominant compounds were retained in the powders. Gas chromatography–mass spectrometry and principal component analysis indicated that the chemical composition was not significantly changed after both drying methods, but small molecular carbonyls, furans and phenols were partially lost. The spray-dried particles had a spherical shape, while freeze-dried particles had irregular shapes because of different powder preparation methods. The particle size of spray-dried powders was in the range of 6.3 to 6.9 µm, while the value for freeze-dried powders was decreased from 580.4 to 134.7 µm by increasing the maltodextrin concentration. The freeze-dried powders performed better in terms of flowability and cohesiveness because of their relatively high density and large particle size. This study revealed that both encapsulation methods could efficiently prepare smoke powder. Spray-drying process would be suitable for large-scale production, while freeze-drying could be used to optimize the encapsulation efficiency of bioactive compounds.

Application of Pickering emulsions in probiotic encapsulation- A review

Probiotics are live microorganisms that confer health benefits to host organisms when consumed in adequate amounts and are often incorporated into foods for human consumption. However, this has negative implications on their viability as large numbers of these beneficial bacteria are deactivated when subjected to harsh conditions during processing, storage, and passage through the gastrointestinal tract. To address these issues, numerous studies on encapsulation techniques to protect probiotics have been conducted. This review focuses on emulsion technology for probiotic encapsulation, with a special focus on Pickering emulsions. Pickering emulsions are stabilized by solid particles, which adsorb strongly onto the liquid-liquid interfaces to prevent aggregation. Pickering emulsions have demonstrated enhanced stability, high encapsulation efficiency, and cost-effectiveness compared to other encapsulation techniques. Additionally, Pickering emulsions are regarded as safe and biocompatible and utilize natural materials, such as cellulose and chitosan derived from plants, shellfish, and fungi, which may also be viewed as more acceptable in food systems than common synthetic and natural molecular surfactants. This article reviews the current status of Pickering emulsion use for probiotic delivery and explores the potential of this technique for application in other fields, such as livestock farming, pet food, and aquaculture.

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Probiotics play an important role in maintaining the health of humans and animals.

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Encapsulation improves probiotic viability in harsh environments.

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Probiotics can be encapsulated by many techniques such as emulsification.

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Pickering emulsions use particles instead of molecules to stabilize emulsions.

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Natural particles are more acceptable to some consumers than synthetic emulsifiers.

Hop Leaves as an Alternative Source of Health-Active Compounds: Effect of Genotype and Drying Conditions

In hop cultivation, one-third of the crop is a valuable product (hop cones), and two-thirds is unexploited biomass, consisting mainly of leaves and stems, which, in a circular economy approach, can be recovered and, once stabilized, supplied to industrial sectors, such as cosmetics, pharmaceuticals and phytotherapy, with high added value. In this regard, this study aimed to investigate the effects of two different drying methods: oven drying (OD) at 45 °C and freeze-drying (FD), on the overall nutraceutical profile (i.e., total phenols, total flavans and total thiols), pigment content (i.e., carotenoids and chlorophylls) and the antioxidant potential of leaves from five different Humulus lupulus varieties grown in central Italy. Moreover, attenuated total reflectance infrared (ATR-FTIR) spectroscopy was applied to dried leaf powders to study the influence of both the variety and treatment on their molecular fingerprints. The spectral data were then analyzed by principal component analysis (PCA), which was able to group the samples mainly based on the applied treatment. Considering the overall phytochemical profile, FD appeared to be the most suitable drying method, while OD provided higher carotenoid retention, depending on the genotype considered. Finally, unsupervised chemometric tools (i.e., PCA and hierarchical clustering) revealed that the two main clusters contained subclusters based on the drying treatment applied; these subgroups were related to the susceptibility of the variety to the drying conditions studied.

Totipotency of Daucus carota L. Somatic Cells Microencapsulated Using Spray Drying Technology

The carrot is considered a model system in plant cell culture. Spray drying represents a widely used technology to preserve microorganisms, such as bacteria and yeasts. In germplasm conservation, the most used methods are freeze drying and cryopreservation. Therefore, the aim of this work was to evaluate the effect of spray drying on the viability and totipotency of somatic carrot cells. Leaf, root and stem explants were evaluated to induce callus with 2 mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D). Calli obtained from the stem were cultivated in a liquid medium with 1 mg/L of 2,4-D. Cell suspensions were spray dried with maltodextrin-gum Arabic and maltodextrin-xanthan gum mixtures, two outlet air temperatures (50 and 60 °C) and 120 °C inlet air temperature. Results showed that carrot cells were viable after spray drying, and this viability remained for six months at 8 °C. The totipotency of the microencapsulated cells was proven. Cells that were not spray dried regenerated 24.6 plantlets, while the spray dried cells regenerated 19 plantlets for each gram of rehydrated powder. Thus, spray drying allowed researchers to obtain viable and totipotent cells. This work is the first manuscript that reported the spray drying of plant somatic cells.

Optimization of fish gelatin drying processes and characterization of its properties

Fish skin is a raw material used for gelatin production. It can satisfy consumers with specific socio-cultural and religious needs. Different technologies have been studied for drying gelatin. Therefore, it is relevant to understand the influence of drying conditions on the final product. This study aims to optimize drying methods such as convection hot air alone and combined with infrared radiation to obtain gelatin from acoupa weakfish skin by using composite central rotational designs 22 and 23 and response surface methodology. The gelatin obtained from the optimized conditions were characterized based on their physical, chemical, technological, and functional properties. The desirability function results show the convection hot air as the most effective method when conducted at 59.14 °C for 12.35 h. Infrared radiation at 70 °C for 2.0 h and convective drying at 70 °C for 3.5 h were the best condition of the combined process. The gelatins obtained had gel strength of 298.00 and 507.33 g and emulsion activity index of 82.46 and 62.77 m2/g in the combined and convective methods, respectively, and protein content above 90%. These results indicate that the processes studied can be used to produce gelatin with suitable technological and functional properties for several applications.

Effects of drying methods and maltodextrin on vitamin C and quality of Terminalia ferdinandiana fruit powder, an emerging Australian functional food ingredient

BACKGROUND

Terminalia ferdinandiana, common name Kakadu plum (KP), fruit is a valuable source of vitamin C, and its concentration can be used as a quality index of KP products, such as dried fruit powder. The present study investigated the effects of two drying methods (freeze-drying and oven-drying) and the addition of maltodextrin (0-25%) on vitamin C, Maillard products, and overall quality of KP fruit powder.

RESULTS

Freeze-drying was a better dehydration technique than oven-drying in retaining vitamin C, reducing the formation of non-enzymatic browning and oxidation products, and improving powder colour (P < 0.05). Non-enzymatic browning products (furfural and 5-hydroxymethyl furfural) were generated in the oven-dried samples as a function of heating and high water activity. Maltodextrin acted as a vitamin C stabilizer in protecting vitamin C from oxidation, and significantly improved the colour attributes of the final dry products. Incorporation of 10-15% maltodextrin could reduce the percentage loss of vitamin C from 8.1% to 3.4% and 18.9% to 11.4% (compared with the control) during freeze-drying and oven-drying, respectively. Scanning electron micrographs revealed differences in the microstructures of the KP powder processed by the two drying methods with different levels of maltodextrin. Multivariate data analysis (principal component analysis) showed separation between the oven-dried and freeze-dried samples, and also suggested that addition of maltodextrin of 7.5-10% and 10-15% are effective for preserving vitamin C and other quality properties of the freeze- and oven-dried KP powder samples, respectively.

CONCLUSION

The results obtained are important for the KP industry, including Indigenous enterprises, in selecting the most appropriate drying method for KP fruit in terms of quality and sustainability. © 2021 Society of Chemical Industry.

Challenges associated with spray drying of lactic acid bacteria: Understanding cell viability loss

Lactic acid bacteria (LAB) cultures used in food fermentation are often dried to reduce transportation costs and facilitate handling during use. Dried LAB ferments are generally lyophilized to ensure high cell viability. Spray drying has come to the forefront as a promising technique due to its versatility and lower associated energy costs. Adverse conditions during spray drying, such as mechanical stress, dehydration, heating, and oxygen exposure, can lead to low LAB cell viability. This reduced viability has limited spray drying's industrial applications thus far. This review aims to demonstrate the operations and thermodynamic principles that govern spray drying, then correlate them to the damage suffered by LAB cells during the spray-drying process. The particularities of spray drying that might cause LAB cell death are detailed in this review, and the conclusion may enhance future studies on ways to improve cell viability.

Microencapsulation of Lactobacillus rhamnosus ATCC 7469 by spray drying using maltodextrin, whey protein concentrate and trehalose

This study aimed to microencapsulate Lactobacillus rhamnosus (L. rhamnosus) ATCC 7469 with whey protein concentrate (WPC), maltodextrin and trehalose by spray drying and to assess the impact of microencapsulation on cell viability and the properties of the dried powders. Spray-drying conditions, including inlet air temperature, air flow rate and feed pump, were fixed as independent variables, while probiotic survival, moisture content, water activity and effective yield were established as dependent variables. The survival of encapsulated L. rhamnosus by spray drying was optimized with response surface methodology, and the stability of the powder was assessed. The optimum spray-drying conditions were an inlet air temperature, air flow rate and feed pump rate of 169 °C, 33 m³·h^-1 and 16 mL·min^-1, respectively, survival of 70%, air aspiration of 84% and outlet air temperature of 52 °C, achieving an overall desirability of 0.96. The physicochemical and structural characteristics of the produced powder were acceptable for application with regard to residual water content, hygroscopicity, water activity, and particle size. The results indicated that a protein-trehalose-maltodextrin mixture is a good wall material to encapsulate L. rhamnosus, showing important thermal protection during the drying process and increasing survival. However, a decrease in this capacity is observed at an air outlet temperature of approximately 101 °C. The possible effects of the wall materials and the drying conditions on survival are also discussed.

Instant Drink Powder Development from Lotus Root with Probiotic Supplement using Foam Mat Drying Method

In this study, we developed instant drink powder of lotus root water using steviol glycoside as a non-nutritive sweetener at different concentrations (0.01, 0.03 and 0.05% w/v) and flavor (Chrysanthemum, Pandan leaves and Roselle) addition on color, pH, %TA, TSS and organoleptic quality properties. The additional of steviol glycoside did not show any effects on physicochemical properties. Results show that 0.03% steviol glycoside and Pandan leaves addition exhibited the highest score of sensorial features significantly. Moreover, this formula was made as foam-mat dried to obtain lotus root supplemented with probiotics powders. The effects of composition ratio of methylcellulose: egg albumin (1:1, 1:2, 1.5:1 and 1.5:2) on the lotus root foam properties were investigated. It was observed that increase in the concentration of methylcellulose decreased foam stability and foam density. Foams were prepared from Lactobacillus plantarum M29 and Peddiococcus pentosaceus MG12 with lotus root water by adding the different concentrations of foaming agents at a whipping time of 15 min. The composition ratio of methylcellulose: egg albumin (1.5:1) provided preferable foam characteristics. The greatest resulting foams were dried at 60 °C for 3 h. The lotus root with probiotics instant drink was able to possess the antioxidant activity and viable probiotics count (more than 7 log CFU/g) during storage at both refrigeration and room temperature for a month.

Targeted Delivery of Probiotics: Perspectives on Research and Commercialization

Considering the significance of the gut microbiota on human health, there has been ever-growing research and commercial interest in various aspects of probiotic functional foods and drugs. A probiotic food requires cautious consideration in terms of strain selection, appropriate process and storage conditions, cell viability and functionality, and effective delivery at the targeted site. To address these challenges, several technologies have been explored and some of them have been adopted for industrial applicability. Encapsulation of probiotics has been recognized as an effective way to stabilize them in their dried form. By conferring a physical barrier to protect them from adverse conditions, the encapsulation approach renders direct benefits on stability, delivery, and functionality. Various techniques have been explored to encapsulate probiotics, but it is noteworthy that the encapsulation method itself influences surface morphology, viability, and survivability of probiotics. This review focuses on the need to encapsulate probiotics, trends in various encapsulation techniques, current research and challenges in targeted delivery, the market status of encapsulated probiotics, and future directions. Specific focus has been given on various in vitro methods that have been explored to better understand their delivery and performance.

Effect of Drying on Nutritional Composition of Atlantic Sea Cucumber (Cucumaria frondosa) Viscera Derived from Newfoundland Fisheries

Cucumaria frondosa is the main sea cucumber species harvested from Newfoundland waters. During processing, the viscera of sea cucumber are usually discarded as waste. As a matter of fact, sea cucumber viscera are abundant in various nutrients and promising for valorization. In the present study, sea cucumber viscera were pretreated by air drying and freeze drying, and the nutritional compositions of the dried products were investigated, including proximate composition, lipid class, fatty acid profile, and amino acid composition. The dried viscera had similar levels of ash, lipids, and proteins compared to fresh viscera. Both air- and freeze-dried viscera had total fatty acid composition similar to fresh viscera, with high levels of omega-3 polyunsaturated fatty acids (PUFAs) (30–31%), especially eicosapentaenoic acid (27–28%), and low levels of omega-6 PUFAs (~1%). The dried samples were abundant in essential amino acids (46–51%). Compared to air-dried viscera, freeze-dried viscera contained a lower content of moisture and free fatty acids, and higher content of glycine and omega-3 PUFAs in phospholipid fraction. The high content of nutritious components in dried viscera of Cucumaria frondosa indicates their great potential for valorization into high-value products.