Enhancing cannabidiol bioaccessibility using ionic liquid as emulsifier to produce nanosystems: Characterization of structures, cytotoxicity assessment, and in vitro digestion.

The emulsifying potential of a biocompatible ionic liquid (IL) to produce lipid-based nanosystems developed to enhance the bioaccessibility of cannabidiol (CBD) was investigated. The IL (cholinium oleate) was evaluated at concentrations of 1 % and 2 % to produce nanoemulsions (NE-IL) and nanostructured lipid carriers (NLC-IL) loaded with CBD. The IL concentration of 1 % demonstrated to be sufficient to produce both NE-IL and NLC-IL with excellent stability properties, entrapment efficiency superior to 99 %, and CBD retention rate of 100 % during the storage period evaluated (i.e. 28 days at 25 °C). The in vitro digestion evaluation demonstrated that the NLC-IL provided a higher stability to the CBD, while the NE-IL improved the CBD bioaccessibility, which was mainly related to the composition of the lipid matrices used to obtain each nanosystem. Finally, it was observed that the CBD cytotoxicity was reduced when the compound was entrapped into both nanosystems.

Performance of ß-carotene-loaded nanostructured lipid carriers under dynamic in vitro digestion system: Influence of the emulsifier type.

A better understanding of how emulsifier type could differently influence the behavior of nanostructured lipid carriers (NLC) under the gastrointestinal digestion process, as well as at the cellular level, is of utmost importance for the NLC-based formulations' optimization and risk assessment in the food field. In this study, NLC composed by fully hydrogenated soybean and high-oleic sunflower oils were prepared using soy lecithin (NLC Lß) or Tween 80 (NLC Tß) as an emulsifier. ß-Carotene was entrapped within NLC developed as a promising strategy to overcome ß-carotene's low bioavailability and stability. The effect of emulsifier type on the digestibility of ß-carotene-loaded NLC was evaluated using an in vitro dynamic digestion model mimicking peristalsis motion. The influence of ß-carotene-loaded NLC on cell viability was assessed using Caco-2 cells in vitro. NLC Tß remained stable in the gastric compartment, presenting particle size (PS) similar to the initial NLC (PS: 245.68 and 218.18 nm, respectively), while NLC Lß showed lower stability (PS > 1000 nm) in stomach and duodenum phases. NLC Tß also provided high ß-carotene protection and delivery capacity (i.e., ß-carotene bioaccessibility increased 10-fold). Based on the results of digestion studies, NLC Tß has shown better physical stability during the passage through the in vitro dynamic gastrointestinal system than NLC Lß. Moreover, the developed NLC did not compromise cell viability up to 25 µg/mL of ß-carotene. Thus, the NLC developed proved to be a biocompatible structure and able to incorporate and protect ß-carotene for further food applications. PRACTICAL APPLICATION: The findings of this study hold significant implications for industrial applications in terms of developing nanostructured lipid carriers from natural raw materials widely available and used to produce other lipid-based products in the food industry, as an alternative to synthetic ones. In this respect, the ß-carotene-loaded NLC developed in this study would find a great industrial application in the food industry, which is in constant search to develop functional foods capable of increasing the bioavailability of bioactive compounds.

Incorporation of curcumin-loaded solid lipid nanoparticles into yogurt: Tribo-rheological properties and dynamic in vitro digestion.

The incorporation of nanostructures loaded with bioactive compounds into food matrices is a promising approach to develop new functional foods with improved nutritional, health profiles and good sensorial properties. The rheological and tribological properties of yogurt enriched with curcumin-loaded solid lipid nanoparticles (SLN) were evaluated. Also, the TCA solubility index, the bioaccessibility of curcumin and cell viability were assessed after dynamic in vitro digestion. The presence of SLN in yogurt did not affect its rheological properties; however, SLN addition increased the lubrication capability of yogurt. After in vitro digestion, yogurt with added SLN (yogurt_SLN) presented a lower TCA solubility index (22 %) than the plain yogurt (39 %). The bioaccessibility and stability of curcumin were statistically similar for yogurt_SLN (30 % and 42 %, respectively) and SLN alone (20 % and 39 %, respectively). Regarding cell viability results, the intestinal digesta filtrates of both controls (i.e., SLN alone and plain yogurt) did not affect significantly the cell viability, while the yogurt_SLN presented a possible cytotoxic effect at the concentrations tested. In general, the incorporation of SLN into yogurt seemed to promote the mouthfeel of the yogurt and did not adversely affect the bioaccessibility of curcumin. However, the interaction of SLN and yogurt matrix seemed to have a cytotoxic effect after in vitro digestion, which should be further investigated. Despite that, SLN has a high potential to be used as nanostructure in a functional food as a strategy to increase the bioactive compounds' bioaccessibility.

Development and characterization of nanostructured lipid carriers for cannabidiol delivery.

This study evaluated the physicochemical characteristics of nanostructured lipid carriers (NLCs) as a potential vehicle for cannabidiol (CBD), a lipophilic molecule with great potential to promote health benefits. NLCs were produced using hemp seed oil and fully-hydrogenated soybean oil at different proportions. The emulsifiers evaluated were soybean lecithin (SL), Tween 80 (T80) and a mixture of SL:T80 (50:50). CBD was tested in the form of CBD-rich extract or isolate CBD, to verify if it affects the NLCs characteristics. Based on particle size and polydispersity, SL was considered the most suitable emulsifier to produce the NLCs. All lipid proportions evaluated had no remarkable effect on the physicochemical characteristics of NLCs, resulting in CBD-loaded NLCs with particle size below 250 nm, high CBD entrapment efficiency and CBD retention rate of 100% for 30 days, demonstrating that NLCs are a suitable vehicle for both CBD-rich extract or isolate CBD.

Assessing the In Vitro Digestion of Lactoferrin-Curcumin Nanoparticles Using the Realistic Gastric Model.

Nanosized delivery systems have been the subject of research and discussion in the scientific community due to their unique properties and functionality. However, studies reporting the behaviour of nanodelivery systems under dynamic in vitro digestion conditions are still very scarce. To address this gap, this study aims to assess the dynamic in vitro gastric digestion of lactoferrin/curcumin nanoparticles in the realistic gastric model (RGM). For this purpose, the INFOGEST standard semi-dynamic digestion protocol was used. The nanosystems were characterized in terms of hydrodynamic size, size distribution, polydispersity index (PdI), and zeta potential using dynamic light scattering (DLS), before and during the digestion process. Confocal laser scanning microscopy (CLSM) was also used to examine particle aggregation. In addition, the release of curcumin was evaluated spectroscopically and the intrinsic fluorescence of lactoferrin was measured throughout the digestion process. The protein hydrolysis was also determined by UV-VIS-SWNIR spectroscopy to estimate, in real-time, the presence of free NH2 groups during gastric digestion. It was possible to observe that lactoferrin/curcumin nanoparticles were destabilized during the dynamic digestion process. It was also possible to conclude that low sample volumes can pose a major challenge in the application of dynamic in vitro digestion models.

Evaluating the in vitro digestion of lipids rich in medium-chain fatty acids (MCFAs) using dynamic and static protocols.

Investigating the digestion of lipids is paramount for developing new lipid-based products. This work evaluated the gastrointestinal (GI) digestion of medium-chain fatty acids (MCFAs) rich lipids. The dynamic GI in vitro system was used to simulate gastric, duodenal, jejunal, and ileal GI tract portions. Results from the dynamic protocol were compared against static in vitro assays and GC analyses were conducted to assess the FA profile of FFA released during digestion. Caprylic and capric acids released during the gastric digestion of MCT oil varied from 61-63% and 36-38% of total esterified FA, respectively. Lauric acid was the most representative FFA released (31-54%) during the gastric digestion of coconut oil samples. It was observed that the gastric digestion phase plays a crucial role in the MCFA lipolysis and the lipase activity restricted the amount of free MCFA liberated during the GI digestion, resulting in incomplete lipids hydrolysis.

Incorporation of curcumin-loaded lipid-based nano delivery systems into food: Release behavior in food simulants and a case study of application in a beverage.

Curcumin-loaded lipid-based nano delivery systems (nanoemulsions-NE, solid lipid nanoparticles-SLN and nanostructured lipid carriers-NLC) were subjected to different food simulants to evaluate curcumin's in vitro release kinetics and particlés stability. The nano delivery systems were also incorporated into a model beverage and their physicochemical properties were evaluated during storing period. Curcumin's bioaccessibility of beverages containing nano delivery systems were assessed through an in vitro digestion process. All nano delivery systems showed a higher curcumin's release and lower particle stability at 50 % ethanol (lipophilic food simulant) comparatively to hydrophilic food simulants. NLC and SLN showed a good particle's stability within the beverage during storing period, while NE presented high instability immediately after incorporation in the beverage. NLC and SLN did not affect beverage's stability relatively to pH, however the beverage with NLC was slightly more stable regarding color. Beverage with SLN presented higher curcumin bioaccessibility compared to the beverage with NLC, however it showed lower curcumin's stability.

Alginate Particles for Encapsulation of Phenolic Extract from Spirulina sp. LEB-18: Physicochemical Characterization and Assessment of In Vitro Gastrointestinal Behavior.

Encapsulation can be used as a strategy to protect and control the release of bioactive extracts. In this work, an extract from Spirulina sp. LEB-18, rich in phenolic compounds, was encapsulated in biopolymeric particles (i.e., composed of alginate) and characterized concerning their thermal behavior using differential scanning calorimetry (DSC), size, morphology, swelling index (S), and encapsulation efficiency (EE%); the release profile of the phenolic compounds at different pHs and the particle behavior under in vitro gastrointestinal digestion were also evaluated. It was shown that it is possible to encapsulate the phenolic extract from Spirulina sp. LEB-18 in alginate particles with high encapsulation efficiency (88.97%). It was also observed that the particles are amorphous and that the encapsulated phenolic compounds were released at a pH 7.2 but not at pH 1.5, which means that the alginate particles are able to protect the phenolic compounds from the harsh stomach conditions but lose their integrity under intestinal pH conditions. Regarding bioaccessibility, it was observed that the encapsulated phenolic compounds showed higher bioaccessibility compared to phenolic compounds in free form. This work increases the knowledge about the behavior of alginate particles encapsulating phenolic compounds during in vitro gastrointestinal digestion. It also provides essential information for designing biopolymeric particle formulations encapsulating phenolic compounds for application in pharmaceutical and food products.

An in vitro fermentation model to study the impact of bacteriophages targeting Shiga toxin-encoding Escherichia coli on the colonic microbiota.

Lytic bacteriophages are considered safe for human consumption as biocontrol agents against foodborne pathogens, in particular in ready-to-eat foodstuffs. Phages could, however, evolve to infect different hosts when passing through the gastrointestinal tract (GIT). This underlines the importance of understanding the impact of phages towards colonic microbiota, particularly towards bacterial families usually found in the colon such as the Enterobacteriaceae. Here we propose in vitro batch fermentation as model for initial safety screening of lytic phages targeting Shiga toxin-producing Escherichia coli (STEC). As inoculum we used faecal material of three healthy donors. To assess phage safety, we monitored fermentation parameters, including short chain fatty acid production and gas production/intake by colonic microbiota. We performed shotgun metagenomic analysis to evaluate the outcome of phage interference with colonic microbiota composition and functional potential. During the 24 h incubation, concentrations of phage and its host were also evaluated. We found the phage used in this study, named E. coli phage vB_EcoS_Ace (Ace), to be safe towards human colonic microbiota, independently of the donors' faecal content used. This suggests that individuality of donor faecal microbiota did not interfere with phage effect on the fermentations. However, the model revealed that the attenuated STEC strain used as phage host perturbed the faecal microbiota as based on metagenomic analysis, with potential differences in metabolic output. We conclude that the in vitro batch fermentation model used in this study is a reliable safety screening for lytic phages intended to be used as biocontrol agents.

Valorization of Amaranth (Amaranthus cruentus) Grain Extracts for the Development of Alginate-Based Active Films.

This research work investigates the development of alginate-based films incorporating phenolic compounds extracted from Amaranthus cruentus grain using different solvents. Alginate, glycerol, and amaranth grain phenolic compounds at various concentrations were used to produce the films. An experimental Central Composite Rotatable Design (CCRD) was used to evaluate the effect of these variables on different film's properties, i.e., water vapor permeability, hydrophobicity, moisture content, solubility, thermal, mechanical, and optical properties. This study demonstrated that high phenolic compound content and antioxidant capacity were obtained from amaranth grain using ethanol as the extraction solvent. Alginate films incorporating amaranth phenolic compounds were successfully manufactured, and this study can be used to tailor the formulation of alginate films containing amaranth phenolic compounds, depending on their final food application. For example, less flexible but more resistant and water-soluble films can be produced by increasing the alginate concentration, which was confirmed by a Principal Component Analysis (PCA) and Partial Least Squares (PLS) analysis. This study showed that active alginate films with amaranth phenolic compounds can be tailored to be used as food packaging material with potential antioxidant activity.

Emerging challenges in assessing bio-based nanosystems' behaviour under in vitro digestion focused on food applications - A critical view and future perspectives.

The current consumers' demand for high quality food products together with the growing awareness regarding the link between health and nutrition has led to the development of novel food products with added functionality. Such functionality can be modulated by adding bio-based nanosystems that can improve the bioaccessibility of bioactive compounds and facilitate nutrient absorption. However, these functional properties can be significantly affected by the adverse conditions (e.g., low pH, presence of enzymes, salts) of the gastrointestinal tract. As such, understanding the behaviour of such delivery systems under digestion conditions is of utmost importance and several analytical tools and in vitro digestion models have been used for this purpose. This review summarizes the latest updates on nanosystems' performance under in vitro digestion and provides critical insights related to important and complementary analytical tools (e.g., rheology, Raman spectroscopy, x-ray scattering) used to assess their performance throughout digestion. Furthermore, the most prominent and frequent challenges associated with such in vitro analyses are also described, together with the current trends regarding the development of in vitro digestion models and some considerations that should be undertaken for their validation. Efforts must be made towards developing reliable and standard in vitro digestion models that use sophisticated analytical techniques to further expand the knowledge regarding nanosystems' behaviour under in vitro digestion conditions.

Dry-salted cod (Gadus morhua) rehydration assisted by pulsed electric fields: modelling of mass transfer kinetics.

BACKGROUND: Dry-salted cod (Gadus morhua) must be rehydrated before consumption and this step can take up to 5 days. Desalting of cod on an industrial scale poses many problems, mainly related to the long processing times and the quality of the final product. For this reason, many researchers have focused on finding new desalting methods to improve mass transfer. The application of pulsed electric fields (PEF) has been proposed as an alternative method for improving mass transfer in many food processes. However, there is no previous literature on the use of PEF to improve animal tissue rehydration. Therefore, the present study aimed to investigate the influence of two PEF pre-treatments [PEF (1) 500 V cm-1 and PEF (2) 1000 V cm-1 ] on mass transport kinetics during the rehydration process of salted cod. The rehydration process was carried out under static conditions for 6 days, immersing dry-salted cod samples in tap water (5 ± 0.5 °C). RESULTS: The results show that the use of PEF technology increases the rate of the rehydration process of dry-salted cod and influences the redistribution of salt. In general, the samples pre-treated with PEF showed higher weight gain and lower salt loss than the control samples during the rehydration process. CONCLUSION: The application of PEF prior to rehydration of salted cod samples could be of interest to the food industry as a result of a higher process yield (higher weight gain) and the possibility to reduce the water renewal because less NaCl is lost in the wastewater. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Incorporation of Solid Lipid Nanoparticles into Stirred Yogurt: Effects in Physicochemical and Rheological Properties during Shelf-Life.

The aim of this work was to develop a yogurt fortified with curcumin. Curcumin is a lipophilic compound with a wide range of biological activities; however, it presents low water solubility and low bioavailability, and therefore it was the first to be encapsulated in solid lipid nanoparticles (SLNs). Then the influence of the incorporation of curcumin-loaded SLNs on the physicochemical (i.e., pH, titratable acidity, syneresis and color) and rheological properties of yogurt during its shelf-life (30 days at 4 °C) was evaluated. SLN incorporation into yogurt did not affect pH and titratable acidity compared to the control (i.e., plain yogurt) during shelf-life, even though the yogurt with SLNs presented lower values of pH (4.25 and 4.34) and acidity (0.74% lactic acid and 0.84% lactic acid) than the control in the end, respectively. Furthermore, the yogurt with SLNs presented slightly higher values of syneresis than the control during the shelf-life; however, it did not present visual differences in whey separation. Relative to the color, the incorporation of SLNs into the yogurt imparted a strong yellow color to the sample but did not affect color stability during shelf-life. Both samples showed flow curves with yield stress and shear-thinning behavior during shelf-life, and, regarding the viscoelastic behavior, both showed a typical weak viscoelastic gel with an elastic structure. Overall, curcumin-loaded SLNs incorporation did not affect the physicochemical and rheological stability of yogurt during shelf-life, showing a promising application for the development of new functional foods.

Lipid-based nanostructures as a strategy to enhance curcumin bioaccessibility: Behavior under digestion and cytotoxicity assessment.

The aim of this study was to evaluate the behavior of different lipid-based nanostructures during in vitro digestion, in particular on curcumin's bioaccessibility, and to access their potential toxicity. Solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) and nanoemulsions (NE) were submitted to harmonized static in vitro digestion and their cytotoxicity and cellular transport were evaluated using Caco-2 cell line. NE presented the highest curcumin's bioaccessibility followed by NLC and SLN, 71.1%, 63.7% and 53.3%, respectively. Free fatty acids percentage increased in the following order: NLC ≤ NE < SLN. Non-digested nanostructures and excipients presented no cytotoxicity; however, digested NE and NLC presented cytotoxicity due to MCT oil, which presented cytotoxicity after digestion. The apparent permeability coefficient of NLC was higher than SLN and NE. These results showed that lipid-based nanostructures' physical state and composition have a high influence on particles' behavior during digestion, and on their cytotoxicity/intestinal permeability, and highlights the importance of conducting cytotoxicity assessments after in vitro digestion. This work contributes to a better understanding of the behavior of lipid-based nanostructures under digestion/adsorption, and this knowledge will be useful in design of nanostructures that afford both safety and an increased bioactive compounds' bioavailability.

Nanoemulsions for Enhancement of Curcumin Bioavailability and Their Safety Evaluation: Effect of Emulsifier Type.

This work aimed at evaluating the effects of different emulsifiers on curcumin-loaded nanoemulsions' behavior during digestion, its safety and absorption, to develop nanoemulsions that provide safety and improved curcumin functionality. Nanoemulsions (NEs) were produced using two bio-based (lecithin (LEC) and rhamnolipids (RHAM)) and one synthetic (Tween®80 (TWE)) emulsifier at similar concentrations. Different NEs were subjected to in vitro digestion. The cytotoxicity and permeability tests were performed in Caco-2 cells. NE_TWE were stable during all phases of in vitro digestion, whereas NE_LEC and NE_RHAM were found to be unstable from the gastric phase. NE_TWE showed 100% of free fatty acids released, followed by NE_RHAM and NE_LEC. Curcumin's bioaccessibility and stability increased in the following order: NE_LEC > NE_RHAM > NE_TWE. NE_LEC and NE_TWE did not show cytotoxic effects in any of the concentrations tested, while NE_RHAM presented high cytotoxicity in all concentrations tested. The apparent permeability coefficients were determined for NE_LEC and NE_TWE; however, the results were not statistically different. These results showed that the emulsifier used has a high impact on nanoemulsions' behavior under the digestion process and on their cytotoxicity. This work contributed to the state-of-the-art's progress on the development of safer curcumin delivery systems with improved functionality, particularly regarding the proper selection of ingredients to produce said systems.

ß-lactoglobulin micro- and nanostructures as bioactive compounds vehicle: In vitro studies.

ß-Lactoglobulin (ß-Lg) is known to be capable to bind hydrophilic and hydrophobic bioactive compounds. This research aimed to assess the in vitro performance of ß-Lg micro- (diameter ranging from 200 to 300 nm) and nano (diameter < 100 nm) structures associated to hydrophilic and hydrophobic model compounds on Caco-2 cells and under simulated gastrointestinal (GI) conditions. Riboflavin and quercetin were studied as hydrophilic and hydrophobic model compounds, respectively. Cytotoxicity experiment was conducted using in vitro cellular model based on human colon carcinoma Caco-2 cells. Moreover, the digestion process was simulated using the harmonized INFOGEST in vitro digestion model, where samples were taken at each phase of digestion process - oral, gastric and intestinal - and characterized in terms of particle size, polydispersity index (PDI), surface charge by dynamic light scattering (DLS); protein hydrolysis degree by 2,4,6-trinitrobenzene sulfonic acid (TNBSA) assay and native polyacrylamide gel electrophoresis; and bioactive compound concentration. Caco-2 cell viability was not affected up to 21 × 10-3 mg mL-1 of riboflavin and 16 × 10-3 mg mL-1 quercetin on ß-Lg micro- and nanostructures. In the oral phase, ß-Lg structures' particle size, PDI and surface charge values were not changed comparing to the initial ß-Lg structures (i.e., before being subjected to in vitro GI digestion). During gastric digestion, ß-Lg structures were resistant to proteolytic enzymes and to acid environment of the stomach - confirmed by TNBSA and native gel electrophoresis. In vitro digestion results indicated that ß-Lg micro- and nanostructures protected both hydrophilic and hydrophobic compounds from gastric conditions and deliver them to target site (i.e., intestinal phase). In addition, ß-Lg structures were capable to enhance riboflavin and quercetin bioaccessibility and bioavailability potential compared to bioactive compounds in their free form. This study indicated that ß-Lg micro- and nanostructures were capable to enhance hydrophilic and hydrophobic compounds bioavailability potential and they can be used as oral delivery systems.

Rice in vitro digestion: application of INFOGEST harmonized protocol for glycemic index determination and starch morphological study.

Starch is the main sugar source present in staple foods. Understanding starch hydrolysis during digestion and the resulting glucose release can be important to strategically modulate starch digestion and glucose absorption. In vitro digestion methodologies are fundamental to evaluate starch hydrolysis length and rate, but the lack of uniformity between protocols prevent the comparison of results. In this context, three different Carolino rice varieties (i.e., Carolino white-Cw, Carolino brown-Cb and Carolino Ariete brown-CAb) were submitted to the INFOGEST harmonized in vitro digestion protocol for the evaluation of starch hydrolysis and subsequent glycemic index (GI) determination, and starch granules morphological study. Samples of Carolino rice presented total starch percentages between 64.52 (for Cb) to 71.52% (for Cw) with low amylose content (16.19-19.95%, varying in the following order Cb < Cab ≈ Cw). During digestion, between 39.43 (for CAb) to 44.48% (for Cb) of starch was hydrolyzed, classifying samples as medium GI foods (61.73-69.17). Starch hydrolysis was accompanied by a decrease of starch granules dimensions. For all samples, area decrease was higher than 59%, perimeter decrease was higher than 37%, feret diameter decrease was higher than 39% and minimum feret diameter decrease was higher than 32%. This work provides new insights to describe, both qualitatively and quantitatively, the fate of rice during digestion, and allowed establishing a comparative basis for the development of rice-based recipes with a lower GI.

Liposomes loaded with phenolic extracts of Spirulina LEB-18: Physicochemical characterization and behavior under simulated gastrointestinal conditions.

Liposomes composed of rice (RL) and soybean (SL) lecithins were produced by reverse phase evaporation and used for the encapsulation of phenolic extracts from Spirulina LEB-18 (S-RL and S-SL for liposomes of rice and soybean lechitin, respectively). Liposomes were characterized in terms of size distribution, polydispersity index, and ζ-potential; the chemical interactions between the phenolic compounds from Spirulina and liposomes were evaluated by Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to evaluate their crystallinity pattern. The release behavior of phenolic extracts was evaluated under two different pH conditions. Afterwards, in vitro digestibility of liposomes was evaluated in a dynamic gastrointestinal system. Liposomes exhibited high encapsulation efficiency (88.28% and 97.35% for S-RL and S-SL, respectively) and sizes ranging between 250 and 291 nm, showing to be good candidates for the encapsulation of phenolic extracts obtained from microalgae. Results showed that liposomes are stable at low pH values and that they are able to resist to the stomach conditions but they lose their integrity under intestinal conditions. This work increases the knowledge about the effects of in vitro gastrointestinal digestion on liposomes and provides important information for the design of liposome formulations aiming their application in pharmaceutical and food applications.

Downscale fermentation for xylooligosaccharides production by recombinant Bacillus subtilis 3610.

The global demand of prebiotics such as xylooligosaccharides (XOS) has been growing over the years, motivating the search for different production processes with increased efficiency. In this study, a cloned Bacillus subtilis 3610, containing the xylanase gene xyn2 of Trichoderma reesei coupled with an endogenous secretion tag, was selected for XOS production through direct fermentation of beechwood xylan. A mixture of XOS with a degree of polymerization ranging from 4 to 6 was obtained, presenting high stability after a static in vitro digestion (98.5 ± 0.2%). The maximum production yield expressed as total XOS per amount of xylan (306 ± 4 mg/g) was achieved after 8 h of fermentation operating under one-time impulse fed-batch. The optimal conditions found were pH 6.0 and 42.5 °C, using 2.5 g/L of initial concentration of xylan increased up to 5.0 g/L at 3 h. Xylopentaose was the major oligosaccharide produced, representing 47% of the total production yield.

Electric Field Processing: Novel Perspectives on Allergenicity of Milk Proteins.

Milk proteins are being widely used in formulated foods as a result of their excellent technological, functional, and biological properties. However, the most representative proteins from casein and whey fractions are also recognized as major allergens and responsible for the prevalence of cow's milk protein allergy in childhood. Electroheating technologies based on thermal processing of food as a result of application of moderate electric fields, also known by ohmic heating (OH) or Joule effect, are establishing a solid foothold in the food industry. Currently, the influence of OH on allergenic aspects of milk proteins is under debate but still undisclosed. The occurrence of electrical effects on the protein structure and its function has already been reported; thus, the impact of OH over allergenicity should not be overlooked. On the basis of these recent findings, it is then relevant to speculate about the impact of this emergent technology on the potential allergenicity of milk proteins.