Supercritical carbon dioxide technology in food processing: Insightful comprehension of the mechanisms of microbial inactivation and impacts on quality and safety aspects.

Supercritical carbon dioxide (SC-CO2) has emerged as a nonthermal technology to guarantee food safety. This review addresses the potential of SC-CO2 technology in food preservation, discussing the microbial inactivation mechanisms and the impact on food products' quality parameters and bioactive compounds. Furthermore, the main advantages and gaps are denoted. SC-CO2 technology application causes adequate microbial reductions (>5 log cfu/mL) of spoilage and pathogenic microorganisms, enzyme inactivation, and improvements in the storage stability in fruit and vegetable products (mainly fruit juices), meat products, and dairy derivatives. SC-CO2-treated products maintain the physicochemical, technological, and sensory properties, bioactive compound concentrations, and biological activity (antioxidant and angiotensin-converting enzyme-inhibitory activities) similar to the untreated products. The optimization of processing parameters (temperature, pressure, CO2 volume, and processing times) is mandatory for achieving the desired results. Further studies should consider the expansion to different food matrices, shelf-life evaluation, bioaccessibility of bioactive compounds, and in vitro and in vivo studies to prove the benefits of using SC-CO2 technology. Moreover, the impact on sensory characteristics and, mainly, the consumer perception of SC-CO2-treated foods need to be elucidated. We highlight the opportunity for studies in postbiotic production. In conclusion, SC-CO2 technology may be used for microbial inactivation to ensure food safety without losing the quality parameters.

Simultaneous Extraction of Bioactive Compounds from Olea europaea L. Leaves and Healthy Seed Oils Using Pressurized Propane.

Olive leaves (OL) are products of olive cultivation with a high commercial value because they contain valuable bioactive compounds. Chia and sesame seeds have a high functional value because of their attractive nutritional properties. When combined in the extraction process, the two products constitute a product of high quality. The use of pressurized propane in vegetable oil extraction is advantageous because it provides solvent-free oil. This study aimed to combine two high-quality products to obtain oils with a unique combination of attractive nutritional properties and high levels of bioactive compounds. The mass percentage yields of the OL extracts with chia and sesame oils were 23.4% and 24.8%, respectively. The fatty acid profiles of the pure oils and their respective OL-enriched oils were similar. There was an aggregation of the 35% and 32% (v/v) bioactive OL compounds in chia and sesame oils, respectively. OL oils exhibited superior antioxidant capacities. The induction times of the OL extracts with the sesame and chia oils increased by 73% and 4.4%, respectively. Incorporating OL active compounds in healthy edible vegetable oils using propane as a solvent promotes the reduction of lipid oxidation, improves the lipid profiles and health indices of the oils, and forms a product with attractive nutritional characteristics.

Effect of citral nanoemulsion on the inactivation of Listeria monocytogenes and sensory properties of fresh-cut melon and papaya during storage.

This study evaluated the survival of Listeria monocytogenes on fresh-cut melon and papaya treated with citral nanoemulsion (CN) during 7 days of storage at 4, 8, 12, and 16 °C. CN was prepared by catastrophic phase inversion, and fresh-cut melon and papaya were artificially inoculated, resulting in 5 log cfu/g of L. monocytogenes. Then, they were treated with 0.30 (CN-0.3) and 0.15 (CN-0.15) µL/mL of CN. CN presented droplet size below 200 nm, monodisperse distribution, and negative surface charge. CN-0.3 reduced the L. monocytogenes counts more efficiently, with counts below the detection limit (1 log cfu/g) in both fruits after 48 h at 4 °C, and 72 h at 8 °C and 12 °C. At 16 °C, L. monocytogenes counts were below the detection limit for CN-0.3 after 120 h in papaya, but it survived the other treatments for 7 days. Both CN-0.3 and CN-0.15 decreased the indigenous microbiota. Scanning electron microscopy (SEM) showed bubbles in L. monocytogenes membrane and cell disruption in fruits treated with CN-0.3. Finally, CN-0.3 treated melon and papaya showed greater brightness, herbal flavor and aroma, firmness, and juiciness, as well as lower sugar and organic acid profile changes than the control samples during storage. Results indicate citral nanoemulsion's efficiency in controlling L. monocytogenes growth on fresh-cut melon and papaya stored at refrigerated temperatures without negatively influencing the sensory parameters.

Thermal and non-thermal treatments in the processing of cagaita nectar - Eugenia dysenterica.

This work aimed to analyze cagaita nectar subjected to different thermal and non-thermal treatments regarding its quality over 30 days of storage (5°C). Ultra (U) and thermosonication (T) were the techniques used for 30 and 60 minutes of processing samples. These techniques proved to be effective to preserve physicochemical quality, regarding rheology and texture, since ultra and thermosonicated samples had their consistency increased when compared to the pasteurized sample over 30 days, a desirable factor for a fruit nectar. Samples treated more intensely with ultrasound and temperature (Pasteurized, U 25°C/60 min and T 60°C/ 30 min) showed higher soluble solids content. The sample U 25°C/60 min increased its brightness, reduced its firmness and also its consistency after 30 storage days. For all samples there was an increase in carotenoids content and a maintenance of viscosity and cohesiveness (texture) over 30 days, thus indicating that the used treatments can be feasible instead of pasteurization, maintaining the shelf life of cagaita nectar in the time evaluated.

Simultaneous extraction of sunflower oil and active compounds from olive leaves using pressurized propane.

Sunflower is grown in different parts of the world and oil from the grain has many uses, including cosmetics and food. Olive leaves are rich in active compounds with potential for industrial use. The simultaneous extraction of raw materials is an economical and sustainable way of using the same extraction process to obtain products with high added value. The aim of this work was to promote the incorporation of bioactive compounds from olive leaves in sunflower oil by two extraction techniques: pressurized propane (PRO) and Soxhlet (SOX) and to evaluate the increase in oxidative stability and antioxidant activity of oils. The techniques used were useful in producing sunflower oil incorporating olive leaf extract (SFO + OLE); 4.3% 1-octacosanol and 5.8% 1-triacontanol were incorporated, and ß-sitosterol increased by at least 90%. Also, SFO + OLE showed an increase in the induction time of 2.7 and 3.7 h compared to SFO for the PRO and SOX methods, respectively. The profile of fatty acids was maintained, with the majority in all samples being oleic and linoleic acids. Consequently, with this procedure is possible to produce SFO + OLE with better antioxidant activity and better nutritional characteristics using PRO and SOX. The scaled-up of the simultaneous extraction process via pressurized propane is economically viable according to the process simulation and economic evaluation.

Vegan probiotic products: A modern tendency or the newest challenge in functional foods.

Vegan consumers represent an attractive economic target for the food industry with demand of products with health benefits, such as probiotic products. This review aimed to explore the so called vegan probiotic products by providing an overview of the commercial and studied products and their associated in vitro/in vivo health-promoting effects, and discuss the effect of probiotics on the technological and sensory properties in a range of products. The factors that impact on the probiotic survival, the main challenges and the trends of this market niche are presented. Vegan probiotic products may improve the lipid profile and the immune system, manage the diabetes, reduce Helicobacter pylori-associated diseases, have anticarcinogenic properties, and improve the general well-being. Fermented and non-fermented beverages are the main vegan probiotic products. The survival of probiotic cultures is dependent on the processing steps, food matrix, probiotic strain and the form of incorporation into the matrix, storage conditions, and addition of prebiotic components. Probiotics may alter the chemical composition, acidity, color, and acceptance of vegan foods and beverages but products with suitable probiotic survival, physicochemical characteristics, technological properties, and sensory acceptance can be obtained. However, the source of the strain may compromise the vegan status since most of those currently available are not isolated from vegetable matrices. Therefore, short-term marketing strategies should focus not only on the vegan public but also on those consumers that want to reduce the consumption of animal-derived products, besides seeking new non-animal derived strains.

Probiotic Greek yogurt: effect of the addition of prebiotic fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance.

In this research communication we evaluate the impact of the addition of prebiotic components (inulin, polydextrose, and modified starch, 40 g/l) as fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance of probiotic (Lacticaseibacillus casei 01, 108 CFU/ml) Greek yogurts during storage (7 °C, 28 d). All formulations had probiotic counts higher than 107 CFU/ml during storage and simulated gastrointestinal conditions (SGIC). The prebiotic components increased the probiotic survival to the enteric phase of the SGIC, with inulin producing the most pronounced effect. Inulin addition resulted in products with lower pH values and consistency and higher titratable acidity during storage, with negative impact on the sensory acceptance (flavor, texture, and overall impression) at the end of the storage period. Modified starch addition impacted negatively on the acceptance of the products (appearance, flavor, texture, and overall impression). Polydextrose addition resulted in products with lower consistency, but similar sensory acceptance to the full-fat yogurt. It can be concluded that it is possible to prepare potentially synbiotic Greek yogurts by desorption technique using L. casei as probiotic culture and inulin, polydextrose or modified starch as prebiotic components, with the utilization of polydextrose being advisable.

Prebiotic frozen dessert processed with water-soluble extract of rice byproduct: Vegan and nonvegan consumers perception using preferred attribute elicitation methodology and acceptance.

The objective of this study was to assess the perceptions (using the preferred attribute elicitation [PAE] methodology) and acceptance of frozen dessert processed with water-soluble extract of rice byproduct and added with prebiotic components (long-chain inulin, medium-chain inulin, oligofructose, or polydextrose, 5 g/100 g) by vegan or nonvegan consumers. Most of the elicited attributes (9 out of 13 attributes, yellow color, brightness, creamy appearance, passion fruit aroma, sweet taste, passion fruit flavor, acid taste, sour taste, and creamy texture) were considered important for the characterization and/or acceptance of the frozen dessert formulations by both groups (vegan and nonvegan), but the order of importance was different between the groups. The sensory profile (Rv = 0.48, P = 0.03 in MFA) of the frozen dessert formulations was similar between vegan and nonvegan groups, and polydextrose contributed to increase firmness/consistency of the frozen dessert, while long-chain inulin contributed to the increase in the creaminess of the products. Finally, oligofructose and polydextrose could reduce the sour taste of the products. The consumers gave scores from 6 to 8 in a 9-point hedonic scale for the products, suggesting suitable acceptance. However, vegan consumers gave lower scores for the same products. In conclusion, PAE methodology can be used to compare the perception of different consumer groups, and vegan and nonvegan consumers have a similar perception about prebiotic frozen dessert processed with water-soluble extract of rice byproduct. Furthermore, the frozen dessert developed had suitable consumer acceptance, although vegan gave lower scores than nonvegan consumers. PRACTICAL APPLICATION: This is the first study involving the development of prebiotic frozen dessert from water-soluble extract of rice byproduct and application of PAE to assess the sensory perception of vegan and nonvegan consumers. The results are important for the industry as they indicate that the PAE methodology can be used to characterize food products, compare the perception of different consumer groups, and elicit attributes that are important for the products, suggesting that universal marketing strategies could be used and that the developed frozen dessert could serve both vegan consumers and those on conventional diets.

Spreadable goat Ricotta cheese added with Lactobacillus acidophilus La-05: Can microencapsulation improve the probiotic survival and the quality parameters?

The impact of the addition of L. acidophilus La-05 (free cells, microencapsulated with alginate [30 g/L] or microencapsulated with alginate coated with chitosan [5 g/L]) on the quality parameters of spreadable goat Ricotta cheese during storage (7 °C/7 days) was evaluated. The addition of probiotic culture resulted in products with lower hardness, gumminess, and springiness, as well as higher cohesiveness and adhesiveness. Furthermore, it increased the yield, and altered the color (higher L*, a* and b* values). The microencapsulation of the probiotic cultures resulted in higher probiotic survival (>6 log CFU/mL in product and simulated gastrointestinal conditions), and improved technological (no moisture loss, lower proteolysis and organic acid content), texture (lower gumminess and adhesiveness), and volatile (compounds with floral and fruity notes and lower "goat" aroma) properties. Chitosan coating did not improve the effects. In conclusion, microencapsulation improved the probiotic survival and the quality parameters of spreadable goat Ricotta cheese.

What to expect from different drugs used in the treatment of COVID-19: A study on applications and in vivo and in vitro results.

The end of 2019 was marked by the emergence of a new type of coronavirus (SARS-CoV-2), which has killed more than 240,000 people around the world so far. Several clinical studies are being performed to test possible drugs in response to the COVID-19 outbreak; however, there is still no treatment that is completely effective. Our goal in this paper is to bring together the results of main studies carried out with different drugs in order to help spread the knowledge about possible treatments for COVID-19 that have been suggested so far.

Mathematical modelling and kinetic study for CD production catalysed by Toruzyme® and CGTase from Bacillus firmus strain 37.

A new mathematical model was developed for the kinetics of α-, ß- and γ-cyclodextrin production, expanding an existing model that only included the production of ß- and γ-cyclodextrins, because a detailed kinetic modelling of the reactions involved allows the manipulation of the process yields. The kinetic behaviour of the commercial enzyme Toruzyme® was studied with maltodextrin as substrate at different concentrations and for CGTase from Bacillus firmus strain 37 at a concentration of 100 g L-1. The mathematical model showed a proper fit to the experimental data, within the 24-h period studied, confirming that the considered hypotheses represent the kinetic behaviour of the enzymes in the reaction medium. The kinetic parameters generated by the model allowed reproducing previous observed qualitative tendencies as it can be seen that changing experimental conditions in the reaction process such as enzyme and substrate concentrations results in large changes in the enzyme kinetics and using high substrate concentrations does not guarantee the highest conversion rates due to enzyme inhibition and reverse reactions. In addition, this new mathematical model complements previous qualitative observations enabling the manipulation of the direct and reverse reactions catalysed by the enzyme by adjusting the reaction conditions, to target quantitative results of increased productivity and better efficiency in the production of a desired cyclodextrin.

Characterization of biocatalysts prepared with Thermomyces lanuginosus lipase and different silica precursors, dried using aerogel and xerogel techniques.

The use of lipases in industrial processes can result in products with high levels of purity and at the same time reduce pollutant generation and improve both selectivity and yields. In this work, lipase from Thermomyces lanuginosus was immobilized using two different techniques. The first involves the hydrolysis/polycondensation of a silica precursor (tetramethoxysilane (TMOS)) at neutral pH and ambient temperature, and the second one uses tetraethoxysilane (TEOS) as the silica precursor, involving the hydrolysis and polycondensation of the alkoxide in appropriate solvents. After immobilization, the enzymatic preparations were dried using the aerogel and xerogel techniques and then characterized in terms of their hydrolytic activities using a titrimetric method with olive oil and by the formation of 2-phenylethyl acetate in a transesterification reaction. The morphological properties of the materials were characterized using scanning electron microscopy, measurements of the surface area and pore size and volume, thermogravimetric analysis, and exploratory differential calorimetry. The results of the work indicate that the use of different silica precursors (TEOS or TMOS) and different drying techniques (aerogel or xerogel) can significantly affect the properties of the resulting biocatalyst. Drying with supercritical CO2 provided higher enzymatic activities and pore sizes and was therefore preferable to drying, using the xerogel technique. Thermogravimetric analysis and differential scanning calorimetry analyses revealed differences in behavior between the two biocatalyst preparations due to the compounds present.