Purple tea (Camellia sinensis var. assamica) leaves as a potential functional ingredient: From extraction of phenolic compounds to cell-based antioxidant/biological activities.

A statistical optimization study was used to maximize the extraction of bioactive compounds and antioxidant activity from green tea derived from purple leaves of Camellia sinensis var. assamica. Simultaneous optimization was applied, and a combination of 60 °C, 15 min, and a mass-solvent ratio of 1 g of dehydrated purple leaves to 62.3 mL of an ethanol/citric acid solution, were determined as the ideal extraction conditions. The optimized extract of purple tea leaves (OEPL) contained showed stability in relation to variations in pH, and lyophilized OEPL exerted cytotoxic and antiproliferative effects against cancerous cells (A549 and HCT8), demonstrated antimicrobial activity towards Listeria monocytogenes (ATCC 7644), Staphylococcus aureus (ATCC 13565) and Staphylococcus epidermidis (ATCC 12288), inhibition of α-amylase and α-glycosidase enzymes and reduced the release of pro-inflammatory cytokines (TNF-α, CXCL2/MIP-2, and IL-6) in lipopolysaccharides-stimulated RAW 264.7 macrophages. Thus, our results provide a broad assessment of the bioactivity of "green" extracts obtained by a simple and low-cost process using non-toxic solvents, and they have the potential to be used for technological applications.

Toxicological and bioactivity evaluation of blackcurrant press cake, sea buckthorn leaves and bark from Scots pine and Norway spruce extracts under a green integrated approach.

Aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), Scots pine bark (SP), and sea buckthorn leaves (SB) were obtained using maceration and pressurized hot water and tested for their bioactivities. Maceration provided the extraction of higher dry matter contents, including total phenolics (TPC), anthocyanins, and condensed tannins, which also impacted higher antioxidant activity. NS and SB extracts presented the highest mean values of TPC and antioxidant activity. Individually, NS extract presented high contents of proanthocyanidins, resveratrol, and some phenolic acids. In contrast, SB contained a high concentration of ellagitannins, ellagic acid, and quercetin, explaining the antioxidant activity and antibacterial effects. SP and BC extracts had the lowest TPC and antioxidant activity. However, BC had strong antiviral efficacy, whereas SP can be considered a potential ingredient to inhibit α-amylase. Except for BC, the other extracts decreased reactive oxygen species (ROS) generation in HCT8 and A549 cells. Extracts did not inhibit the production of TNF-alpha in lipopolysaccharide-stimulated THP-1 macrophages but inhibited the ROS generation during the THP-1 cell respiratory burst. The recovery of antioxidant compounds from these by-products is incentivized for high value-added applications.

Application of essential oils as antimicrobial agents against spoilage and pathogenic microorganisms in meat products.

Meat and meat products are perishable products that require the use additives to prevent the spoilage by foodborne microorganisms and pathogenic bacteria. Current trends for products without synthetic preservatives have led to the search for new sources of antimicrobial compounds. Essential oils (EOs), which has been used since ancient times, meet these goals since their effectiveness as antimicrobial agents in meat and meat products have been demonstrated. Cinnamon, clove, coriander, oregano, rosemary, sage, thyme, among others, have shown a greater potential to control and inhibit the growth of microorganisms. Although EOs are natural products, their quality must be evaluated before being used, allowing to grant the Generally Recognized as Safe (GRAS) classification. The bioactive compounds (BAC) present in their composition are linked to their activity, being the concentration and the quality of these compounds very important characteristics. Therefore, a single mechanism of action cannot be attributed to them. Extraction technique plays an important role, which has led to improve conventional techniques in favour of green emerging technologies that allow to preserve better target bioactive components, operating at lower temperatures and avoiding as much as possible the use of solvents, with more sustainable processing and reduced energy use and environmental pollution. Once extracted, these compounds display greater inhibition of gram-positive than gram-negative bacteria. Membrane disruption is the main mechanism of action involved. Their intense characteristics and the possible interaction with meat components make that their application combined with other EOs, encapsulated and being part of active film, increase their bioactivity without modifying the quality of the final product.

Black aspergilli in Brazilian onions: From field to market.

The occurrence of black aspergilli in onions has been reported as frequent, and this group of fungi harbors potentially toxigenic species. In addition, Aspergillus niger has been reported as the causative agent of black mold rot, an important postharvest disease that causes damage throughout the world. Brazil stands out as one of the world's largest onion producers. However, few studies have been conducted to investigate the mycobiota in Brazilian onions. For this reason, we investigated the mycobiota of 48 market (n = 25) and field (n = 23) onion bulb samples. Nineteen soil samples were collected from the same fields and evaluated. In field onions and soil samples, Penicillium spp. was the prevalent fungal group, whereas in market samples A. section Nigri was the most frequent group. Due to the taxonomic complexity of this group, species identification was supported by phylogenetic data (CaM gene). A. welwitschiae was the most prevalent species in market samples. Black aspergillus strains were evaluated for fumonisin B2 (FB2) and ochratoxin A (OTA) production. Overall, 53% and 2.2% of the strains produced FB2 and OTA, respectively. The occurrence of FB2 and OTA was also investigated in onion bulb samples but none showed contamination with these mycotoxins.

Antimicrobial photodynamic treatment as an alternative approach for Alicyclobacillus acidoterrestris inactivation.

Alicyclobacillus acidoterrestris is a cause of major concern for the orange juice industry due to its thermal and chemical resistance, as well as its spoilage potential. A. acidoterrestris spoilage of orange juice is due to off-flavor taints from guaiacol production and some halophenols. The present study aimed to evaluate the effectiveness of antimicrobial Photodynamic Treatment (aPDT) as an emerging technology to inactivate the spores of A. acidoterrestris. The aPDT efficiency towards A. acidoterrestris was evaluated using as photosensitizers the tetracationic porphyrin (Tetra-Py+-Me) and the phenothiazinium dye new methylene blue (NMB) in combination with white light-emitting diode (LED; 400-740 nm; 65-140 mW/cm2). The spores of A. acidoterrestris were cultured on YSG agar plates (pH 3.7 ± 0.1) at 45 °C for 28 days and submitted to the aPDT with Tetra-Py+-Me and NMB at 10 µM in phosphate-buffered saline (PBS) in combination with white light (140 mW/cm2). The use of Tetra-Py+-Me at 10 µM resulted in a 7.3 ± 0.04 log reduction of the viability of A. acidoterrestris spores. No reductions in the viability of this bacterium were observed with NMB at 10 µM. Then, the aPDT with Tetra-Py+-Me and NMB at 10 µM in orange juice (UHT; pH 3.9; 11°Brix) alone and combined with potassium iodide (KI) was evaluated. The presence of KI was able to potentiate the aPDT process in orange juice, promoting the inactivation of 5 log CFU/mL of A. acidoterrestris spores after 10 h of white light exposition (140 mW/cm2). However, in the absence of KI, both photosensitizers did not promote a significant reduction in the spore viability. The inactivation of A. acidoterrestris spores artificially inoculated in orange peels (105 spores/mL) was also assessed using Tetra-Py+-Me at 10 and 50 µM in the presence and absence of KI in combination with white light (65 mW/cm2). No significant reductions were observed (p < .05) when Tetra-Py+-Me was used at 10 µM, however at the highest concentration (50 µM) a significant spore reduction (≈ 2.8 log CFU/mL reductions) in orange peels was observed after 6 h of sunlight exposition (65 mW/cm2). Although the color, total phenolic content (TPC), and antioxidant capacity of orange juice and peel (only color evaluation) seem to have been affected by light exposition, the impact on the visual and nutritional characteristics of the products remains inconclusive so far. Besides that, the results found suggest that aPDT can be a potential method for the reduction of A. acidoterrestris spores on orange groves.

Response surface optimization of phenolic compounds extraction from camu-camu (Myrciaria dubia) seed coat based on chemical properties and bioactivity.

Food companies should comply with the requirements of a zero-waste concept to adapt to the circular economy requirements. In fruit companies, usually seeds are discarded without proper utilization and extraction of the bioactive compounds. Fruit seeds are sources of chemical compounds that can be extracted, studied, and applied in high value-added products. Thus, in this work the experimental conditions for the water extraction of phenolic compounds from camu-camu (Myrciaria dubia) seed coat were optimized using a central composite design and the desirability function. Total phenolic content (TPC), and condensed tannins (CT), DPPH radical scavenging activity, ferric reducing antioxidant capacity (FRAP), Folin-Ciocalteu reducing capacity (FCRC), and Cu2+ chelating ability were assessed. Seed coat extracted for 51.1 min using a 1:34.1 solid:liquid ratio was the optimal condition to extract 6,242 mg gallic acid equivalent (GAE)/100 g of TPC and 695 mg catechin equivalent (CE)/100 g of CT. The optimized extract displayed free-radical scavenging activity, reducing properties and ability to chelate Cu2+ , and inhibited the growth of Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella Typhimurium, Salmonella Enteritidis, Bacillus cereus, and Staphylococcus aureus. Additionally, the lyophilized water extract inhibited the in vitro activity of α-amylase, α-glucosidase, and angiotensin converting enzyme and showed cytotoxic effects towards Caco-2, A549, and HepG2 cancer cells, but no cytotoxicity towards IMR90 cells. Vescalagin, castalagin, and 3,4-dihydroxybenzoic acid were the major phenolic compounds identified in the optimized extract. In conclusion, the optimized camu-camu seed coat water extract is a rich source of phenolic compounds with antioxidant, antidiabetic, antihypertensive, and antiproliferative effects. PRACTICAL APPLICATION: Camu-camu fruit pulp and seeds have been studied for their phenolic composition and bioactivity. However, seeds are usually discarded and represent an environmental problem in South American countries. We presented a methodological overview on the extraction optimization of the phenolic compounds from camu-camu seed coat and studied the bioactivity of the optimized extract using chemical, enzymatic, and cell-based experiments. Results can be used by camu-camu processors to obtain a phenolic-rich extract for industrial applications, without any further processing.

Response surface optimization of phenolic compounds from jabuticaba (Myrciaria cauliflora [Mart.] O.Berg) seeds: Antioxidant, antimicrobial, antihyperglycemic, antihypertensive and cytotoxic assessments.

The aim of this study was to evaluate the effects of different solvents and maximize the extraction of bioactive compounds from jabuticaba (Myrciaria cauliflora) seeds. In general, the solvent system composed of water and propanone (52:48 v/v) modified the extract polarity and increased extraction yield of bioactive compounds. The optimized extract presented antioxidant capacity measured by different chemical and biological assays. The optimized extract exerted antiproliferative and cytotoxic effects against A549 and HCT8 cells, antimicrobial and antihemolytic effects, inhibited α-amylase/α-glucosidase activities and presented in vitro antihypertensive effect. Nonetheless, the optimized extract showed no cytotoxicity in a human cell model (IMR90). Vescalagin, castalagin and ellagic acid were the major phenolic compounds in the optimized extract. Our results show that jabuticaba seed may be a potential ingredient for the development of potentially functional foods.

Evaluation of fruta-do-lobo (Solanum lycocarpum St. Hill) starch on the growth of probiotic strains.

Fruta-do-lobo (Solanum lycocarpum St. Hill) is a native fruit commonly used in Brazilian folk medicine as a hypoglycemic agent. These properties are attributed to their starch, mainly its resistant fraction. Resistant starch has shown to increases the growth of Bifidobacterium and Lactobacillus in the gut, even though not being selective for these strains. In this scenario, this study aimed to investigate the potential prebiotic activity of fruta-do-lobo starch (FLS). FLS showed around 30% of resistant starch and their prebiotic potential was evaluated with five probiotic strains L. acidophilus (LA3 and LA5), L. casei (LC01) and B. animalis (BB12) and B. lactis (BLC1) in a concentration range of 1.0-2.0% of starch. In a preliminary screening, we evaluated, during 48 h, the viability of the starch with promoting growth agent. An increase in the growth of the probiotic strains tested was observed. We also evaluated the microorganism's metabolic activity by assessing the short-chain fatty acid (SCFA) production, using the best starch growth promotion conditions (2% of FLS and strains BLC1, LA5, and LC01). As expected, MRS and lactose were preferentially metabolized by BLC1, with the highest growth rates: 0.231 and 0.224 h-1, respectively. However, for this strain, the FLS growth rate (0.222 h-1) was 65% higher than FOS (0.144 h-1). Also, for LA5 FLS promoted higher growth (0.150 h-1) than FOS (0.135 h-1). Additionally, FLS promoted acetate production. These data are promising and indicate that FLS may have prebiotic potential and more studies need to be done with pathogenic microorganisms.

Clitoria ternatea L. petal bioactive compounds display antioxidant, antihemolytic and antihypertensive effects, inhibit α-amylase and α-glucosidase activities and reduce human LDL cholesterol and DNA induced oxidation.

The purpose of this study was to use a statistical approach to optimise the experimental conditions regarding the extraction of bioactive compounds, and to analyse the in vitro functional properties of crude lyophilized extracts (CLE) and partially purified (PPE) extracts of Clitoria ternatea petals. The results showed that the factors of temperature and time influenced the extraction of phenolic compounds, antioxidant activity and the physicochemical parameters. Simultaneous optimisation showed that the same levels of bioactive compounds were extracted when using temperatures from 11.7 to 68.3 °C and times from 8.47 to 51.12 min. Principal component analysis revealed the experimental conditions that provided the extraction producing the highest level of phenolic content (40 °C/30 min). The CLE showed antimicrobial activity; protective effect against hemolysis of erythrocytes; inhibition of α-amylase, α-glucosidase and angiotensin-I-converting (ACE-I) enzymes; and inhibition of lipid peroxidation. The CLE and PPE demonstrated oxygen radical absorption capacity; inhibition of DNA strand scission; inhibition of LDL cholesterol oxidation; intracellular antioxidant activity against reactive oxygen species (>100 µg/mL); and no cytotoxicity (IC50, GI50 and LC50 > 900 µg/mL) against A549, HCT8 and IMR90 cell lines.

Natural products with preservative properties for enhancing the microbiological safety and extending the shelf-life of seafood: A review.

Seafood is highly perishable, presenting a rapid loss of its quality soon after capture. Temperature is the critical parameter that impacts on seafood shelf-life reduction, allowing the growth of foodborne pathogens and spoilage microorganisms. In recent years, the search by additional methods of preserving seafood has increased, able to ensure quality and safety. Several natural preservatives have highlighted and gained considerable attention from the scientific community, consumers, industry, and health sectors as a method with broad action antimicrobial and generally economical. Natural preservatives, from different sources, have been widely studied, such as chitosan from animal sources, essential oils, and plant extracts from a plant source, lactic acid bacteria, and bacteriocins from microbiological sources and organic acid from different sources, all with great potential for use in seafood systems. This review focuses on the natural preservatives studied in seafood matrices, their forms of application, concentrations usually employed, their mechanisms of action, factors that interfere in their use and the synergistic effect of the interactions among the natural preservatives, with a focus for maintenance of quality and ensure of food safety.

Camu-camu seed (Myrciaria dubia) - From side stream to anantioxidant, antihyperglycemic, antiproliferative, antimicrobial, antihemolytic, anti-inflammatory, and antihypertensive ingredient.

Camu-camu (Myrciaria dubia) seeds are discarded without recovering the bioactive compounds. The main aim of the present work was to optimise the solvent mixture to extract higher total phenolic content and antioxidant capacity of camu-camu seeds. The optimised solvent system increased the extraction of phenolic compounds, in which vescalagin and castalagin were the main compounds. The optimised extract displayed antioxidant capacity measured by different chemical and biological assays, exerted antiproliferative and cytotoxic effects against A549 and HCT8 cancer cells, antimicrobial effects, protected human erythrocytes against hemolysis, inhibited α-amylase and α-glucosidase enzymes and presented in vitro antihypertensive effect. Additionally, the optimized extract inhibited human LDL copper-induced oxidation in vitro and reduced the TNF-α release and NF-κB activation in macrophages cell culture. Thus, the use of camu-camu seed showed to be a sustainable way to recover bioactive compounds with in vitro functional properties.

Ethnopharmacology, phytochemistry and biological activity of Erodium species: A review.

Erodium spp. is a genus that can be found in all continents that has been traditionally used in folk medicine to treat many diseases such as hemorrhage, dermatological disorders, indigestion, and inflammatory diseases. Moreover, Erodium leaves have been used for the preparation of salads, omelets, sandwiches, sauces and soups, among other food products. The objective of this review was to show the recent and relevant studies about extraction of bioactive compounds, the phytochemical characterization, the potential biological activities and toxicological evidence reported in both in vitro and in vivo studies from Erodium spp. In addition, the use of Erodium spp. as natural compounds against the development of diseases were also showed. This review highlights the traditional use of Erodium species in several countries as a therapeutic agent to treat several diseases (such as constipation, dermatological disorders, diabetes, indigestion, urinary inflammations, and as carminative agent), the factors influencing the extraction of bioactive compounds (mainly species and solvent composition on phenolic compounds) and phytochemical profile (presence of essential oils and alkaloids), the scientific evidence about its anti-inflammatory, antimicrobial (against both spoilage and pathogenic microorganisms), antiviral and other health-related activities (anti-protozoal and anti-viral activity) as well as the toxicological evidence. Erodium spp. is a relevant source of compounds with antioxidant, antimicrobial, and biological activity, which support its potential exploration in pharmacological and food area. Major efforts are necessary to advance the knowledge about Erodium genus regarding the relation between traditional use and scientific evidence, optimization of extraction conditions, the influence on biological mechanisms at animal and clinical levels, and bioaccessibility and bioavailability of bioactive compounds.

Antioxidants-rich ice cream containing herbal extracts and fructooligossaccharides: manufacture, functional and sensory properties.

This work aimed to optimize an aqueous extract rich in phenolic compounds and potential functional properties made of Ilex paraguariensis, Melissa officinalis, and Cymbopogon citratus. The lyophilized extract was used for the development of an ice cream. Total phenolics, FRAP, DPPH, Folin-Ciocalteu's reducing capacity, and total reducing capacity of different combinations of herbal extracts were tested and modeled using response surface methodology. Simultaneous optimisation was employed to maximize the bioactive compounds in the extract and the lyophilized optimum combination was added to ice cream. The lyophilized extract contained quercetin-3-rutinoside, hesperidin, isoquercetin, caffeic acid, and 5,7-dihydroxyflavone. The optimised extract, which showed antihypertensive, antidiabetic, and antioxidant activity using in vitro protocols, increased total phenolics and antioxidant activity in comparison to the control ice cream. The ice cream presented a sensory acceptance index of 83%. After 72 days of storage (-18 °C), total phenolics and antioxidant activity significantly decreased.

Influence of pitanga leaf extracts on lipid and protein oxidation of pork burger during shelf-life.

The effect of pitanga leaf extracts, as source of natural antioxidants, on physicochemical properties as well as lipid and protein oxidation of pork burgers during storage at 2 ±â€¯1 °C, packed under modified atmosphere, was assessed. Formerly, the in vitro antioxidant and antimicrobial activities as well as the phenolic profile of pitanga leaf extracts were also studied. Thereafter, five samples were prepared, including control (without antioxidants), commercial synthetic antioxidant (BHT at 200 mg/kg) and three concentrations of pitanga leaf extracts: PLL (at 250 mg/kg), PLM (at 500 mg/kg) and PLH (at 1000 mg/kg). The predominant phenolic compounds identified in pitanga leaf extracts were hydroxycinnamic acids, followed by tyrosol and other phenolics (alkylmethoxyphenols, hydroxycoumarins and hydroxyphenylpropenes). Pitanga leaf extracts showed a high antioxidant and antimicrobial in vitro activity. The addition of pitanga leaf extracts improved the redness of pork burgers during the whole display. On the other hand, the addition of natural antioxidants decreased the lipid oxidation from day 7 till the end of storage period. Burgers with antioxidant showed a similar protein oxidation level, observing an inhibition between 36% and 49% compared to control treatment. From the results, it can be concluded that pitanga leaf extract is a good alternative to commercial synthetic antioxidants to improve the quality and extend the shelf-life of pork burgers.

Guarana seed extracts as a useful strategy to extend the shelf life of pork patties: UHPLC-ESI/QTOF phenolic profile and impact on microbial inactivation, lipid and protein oxidation and antioxidant capacity.

The antioxidant and antimicrobial effects of guarana seed extracts (GSE) added to pork patties were evaluated for 18 days storage at 2 ±â€¯1 °C. Five treatments were prepared: i) without natural antioxidant [control (negative control)], ii) with BHT at 200 mg/kg (positive control), and iii) with three different concentrations: 250  mg/kg (guarana seed low dose-GSL), 500  mg/kg (guarana seed medium dose-GSM) and 1000  mg/kg (guarana seed high dose-GSH) of guarana extracts, respectively. The pH, instrumental colour (CIE L*, a*, b*), total viable counts (TVC), Pseudomonas spp. counts and lactic acid bacteria (LAB) counts, 2-thiobarbituric acid reactive substances (TBARS) and carbonyl content were determined after 0, 7, 11, 15 and 18 days of storage period. The in vitro antioxidant activity together with the phenolic profile of GSE was also studied. Microbial analysis showed that GSE had no antimicrobial activity on pork patties. The untargeted UHPLC-ESI-QTOF approach confirmed the wide phenolic composition of GSE able to explain the antioxidant power (28.2 g/kg of phenolic equivalents). Low doses (GSL) of GSE were able to preserve the values of colour parameters, obtaining higher L*, a* and b* values during storage, which is reflected in the lowest colour differences during storage (ΔE*0-18 = 4.56). TBARS and carbonyls values in GSE added samples were lower than control and BHT ones. GSL and GSM provided better results than the synthetic antioxidant (0.08 and 0.07 vs 0.18 mg MDA/kg; 2.47 and 3.13 vs 3.23 nmol/mg, for GSL and GSM vs BHT, respectively). These findings show that GSE are very effective against colour deterioration, lipid and protein oxidation in pork patties and possessing the potential to be used as natural antioxidants.

Essential oils as natural additives to prevent oxidation reactions in meat and meat products: A review.

Oxidation reactions during manufacturing, distribution, and storage of meat and meat products result in undesirable physicochemical changes and aromas, which leads to detrimental effects on the product quality. This could be translated into the consumer dissatisfaction and economic loss. One of the most common practices to overcome this issue is the incorporation of synthetic antioxidants. However, the increasing health-consciousness of consumers and their preference for natural additives leads to the search of natural alternatives to synthetic antioxidants. A number of essential oils have strong antioxidant properties and are explored as potential alternatives to chemical antioxidants in the meat industry. These compounds are classified as Generally Recognized as Safe (GRAS), and their application single or combined with other essential oils, ingredients or preservation technologies have beneficial effects on meat products. Their activity depends on several parameters including their concentrations, their possible synergistic effects, and the extraction method used to obtain them. Although steam distillation is the most common industrial technique for essential oils extraction, novel technologies have been emerged to address the drawbacks of the traditional extraction method and to obtain high-quality essential oils. This paper provides an overview of the application of essential oils as potential substitutes for synthetic antioxidants in the meat industry, exploring their mechanism of action against oxidation reactions, and the effect of extraction methods on their effectiveness.

Solid lipid microparticles loaded with cinnamon oleoresin: Characterization, stability and antimicrobial activity.

Cinnamon bark oleoresin (CO) is a natural flavoring that has several biological properties and can act as an antimicrobial agent. However, oleoresins are susceptible to degradation by light, oxygen and temperature. Thus, the objective of this work was the production and characterization of microparticles loaded with CO obtained by the spray chilling technique. Hardfat (PH) and palm oil (PO) were used as carriers in different proportions: 100:0; 80:20; 60:40, respectively. The active concentration was 1 and 2%. Solid lipid microparticles (SLM) were stored at 25 and 45°C having their polymorphism, retention capacity of the volatile compounds and antimicrobial capacity assessed over 28 days. CO presented cinnamaldehyde (Cn), O-methoxy cinnamaldehyde (OmCn) and coumarin (Co) as the major volatile components. The minimum inhibitory concentration (MIC) of the CO against molds, yeasts and Gram-negative bacteria was of 0.1% (v/v), for every microorganism. In the SLM characterization there was a significant size variation, with a mean diameter (d 0.5) in the range of 8-72 µm. Most of the formulations showed crystals in the polymorphic form ß '. The formulation containing only PH as the carrier agent and 2% CO was able to better retain the volatile compounds. During the storage period, formulations F2 and F3, containing proportions of HP and OP of 80:20 and 60:40, respectively, and 2% CO, showed the best stabilities in relation to the concentration of Cn. The antimicrobial activity of the SLM against Candida pseudointermedia and Penicillium paneum, evaluated by the diameter of inhibition zone, increased over the 28 days of storage.

Chemical study, antioxidant, anti-hypertensive, and cytotoxic/cytoprotective activities of Centaurea cyanus L. petals aqueous extract.

This study aimed to optimise the experimental conditions of extraction of the phytochemical compounds and functional properties of Centaurea cyanus petals. The following parameters were determined: the chemical composition (LC-ESI-MS/MS), the effects of pH on the stability and antioxidant activity of anthocyanins, the inhibition of lipid peroxidation, antioxidant activity, anti-hemolytic activity, antimicrobial, anti-hypertensive, and cytotoxic/cytoprotective effect, and the measurements of intracellular reactive oxygen species. Results showed that the temperature and time influenced (p ≤ 0.05) the content of flavonoids, anthocyanins, and FRAP. Only the temperature influenced the total phenolic content, non-anthocyanin flavonoids, and antioxidant activity (DPPH). The statistical approach made it possible to obtain the optimised experimental extraction conditions to increase the level of bioactive compounds. Chlorogenic, caffeic, ferulic, and p-coumaric acids, isoquercitrin, and coumarin were identified as the major compounds in the optimised extract. The optimised extract presented anti-hemolytic and anti-hypertensive activity in vitro, in addition to showing stability and reversibility of anthocyanins and antioxidant activity with pH variation. The C. cyanus petals aqueous extract exhibited high IC50 and GI50 (>900 µg/mL) values for all cell lines, meaning low cytotoxicity. Based on the stress oxidative assay, the extract exhibited pro-oxidant action (10-100 µg/mL) but did not cause damage or cell death.

Inter- and intra-species variability in heat resistance and the effect of heat treatment intensity on subsequent growth of Byssochlamys fulva and Byssochlamys nivea.

The major aims of this study were to assess inter- and intra-species variability of heat resistant moulds (HRMs), Byssochlamys fulva and Byssochlamys nivea, with regards to (i) heat resistance and (ii) effect of heat treatment intensity on subsequent outgrowth. Four-week-old ascospores were suspended in buffered glucose solution (13° Brix, pH 3.5) and heat treated in a thermal cycler adjusted at 85 °C, 90 °C and 93 °C. Two variants of the Weibull model were fitted to the survival data and the following inactivation parameters estimated: b (inactivation rate, min-1), n (curve shape) and δ (the time taken for first decimal reduction, min). In addition to the assessment of heat resistance, outgrowth of Byssochlamys sp. from ascospores heated at 70 °C, 75 °C, 80 °C, 85 °C and 90 °C for 10 min and at 93 °C for 30 and 70 s was determined at 22 °C for up to 30 days. The Baranyi and Roberts model was fitted to the growth data to estimate the radial growth rates (µmax, mm.day-1) and lag times (λ, days). Inter-species variability and significant differences (p < 0.05) were observed for both inactivation and growth estimated parameters among B. fulva and B. nivea strains. The effect of heat treatment intensity on outgrowth of B. fulva strains was more apparent at the most intense heat treatment evaluated (90 °C/10 min), which was also the condition in which greater dispersion of the estimated kinetic parameters was observed. On the other hand, B. nivea strains were more affected by heating, resulting in greater variability of growth parameters estimated at different heating intensities and in very long lag phases (up to 25 days). The results show that inter- and intra-species variability in the kinetic parameters of Byssochlamys sp. needs to be taken into account for more accurate spoilage prediction. Furthermore, the effect of thermal treatments on subsequent outgrowth from ascospores should be explored in combination with other relevant factors such as °Brix and oxygen to develop thermal processes and storage conditions which can prevent the growth of HRMs and spoilage of heat treated food products.

Optimized Camellia sinensis var. sinensis, Ilex paraguariensis, and Aspalathus linearis blend presents high antioxidant and antiproliferative activities in a beverage model.

A statistical optimization study was conducted to obtain a tea containing fermented rooibos (Aspalathus linearis), white tea (Camellia sinensis var. sinensis), and roasted mate (Ilex paraguariensis). An optimal combination of these species was proposed. This optimized tea inhibited 64% the lipoperoxidation in vitro and presented a high phenolic content, especially kaempferol, (+)-catechin, (-)-epicatechin, rutin, (-)-epigallocatechin, and (-)-epicatechin-2-O-gallate. Indeed, the antioxidant effect was confirmed by decreasing 30% the reactive oxygen species generation in human hepatoma carcinoma cells (HepG2, 100 and 240 µg/mL). In the cell viability assay, the GI50 for human colorectal adenocarcinoma epithelial cells (Caco-2) was about 547 µg/mL and 481 µg/mL for HepG2. The pasteurization process (65 °C/30 min) did not affect the total phenolic content and antioxidant activity of the optimized tea formulation. The sensory test indicated an acceptability index of 78%, showing that the analytical approach adopted was feasible to develop a phenolic-rich beverage.