Alicyclobacillus spp. in fruit-based products: Isolation, identification, quantitative assessment (SPME/GC-MS) of spoilage compounds and spore's resistance to thermal shocks.

Alicyclobacillus spp. is the cause of great concern for the food industry due to their spores' resistance (thermal and chemical) and the spoilage potential of some species. Despite this, not all Alicyclobacillus strains can spoil fruit juices. Thus, this study aimed to identify Alicyclobacillus spp. strains isolated from fruit-based products produced in Argentina, Brazil, and Italy by DNA sequencing. All Alicyclobacillus isolates were tested for guaiacol production by the peroxidase method. Positive strains for guaiacol production were individually inoculated at concentration of 103 CFU/mL in 10 mL of orange (pH 3.90) and apple (pH 3.50) juices adjusted to 11°Brix, following incubation at 45 °C for at least 5 days to induce the production of the following spoilage compounds: Guaiacol, 2,6-dichlorophenol (2,6-DCP) and 2,6-dibromophenol (2,6-DBP). The techniques of micro-solid phase extraction by headspace (HS-SPME) and gas-chromatography with mass spectrometry (GC-MS) were used to identify and quantify the spoilage compounds. All GC-MS data was analyzed by principal component analysis (PCA). The effects of different thermal shock conditions on the recovery of Alicyclobacillus spores inoculated in orange and apple juice (11°Brix) were also tested. A total of 484 strains were isolated from 48 brands, and the species A. acidocaldarius and A. acidoterrestris were the most found among all samples analyzed. In some samples from Argentina, the species A. vulcanalis and A. mali were also identified. The incidence of these two main species of Alicyclobacillus in this study was mainly in products from pear (n = 108; 22.3 %), peach (n = 99; 20.5 %), apple (n = 86; 17.8 %), and tomato (n = 63; 13 %). The results indicated that from the total isolates from Argentina (n = 414), Brazil (n = 54) and Italy (n = 16) were able to produce guaiacol: 107 (25.8 %), 33 (61.1 %) and 13 (81.2 %) isolates from each country, respectively. The PCA score plot indicated that the Argentina and Brazil isolates correlate with higher production of guaiacol and 2,6-DCP/2,6-DBP, respectively. Heatmaps of cell survival after heat shock demonstrated that strains with different levels of guaiacol production present different resistances according to spoilage ability. None of the Alicyclobacillus isolates survived heat shocks at 120 °C for 3 min. This work provides insights into the incidence, spoilage potential, and thermal shock resistance of Alicyclobacillus strains isolated from fruit-based products.

Large scale survey of yeasts in frozen concentrated orange juice (FCOJ): Occurrence, diversity, and resistance to peracetic acid.

This study aimed to evaluate the occurrence and diversity of yeasts in frozen concentrated orange juice (FCOJ) and assess the resistance of yeasts to peracetic acid. One thousand five hundred (n = 1500) samples of frozen concentrated orange juice (FCOJ) were analyzed, and 280 yeast strains were isolated and identified. Candida represented 37% of all isolates, and the main species identified were Candida pseudointermedia and C. orthopsilosis. Other yeasts identified were Starmerella, Wickerhamiella, Wickerhamiella, Clavispora, Kodamaea, Meyerozyma, Rhodotorula, Trichosporon, Wickerhamomyces, Kluyveromyces, Hanseniaspora, Saccharomyces, Torulaspora, and Zygosaccharomyces. The exogenous origin of the contamination in FCOJ samples analyzed was shown by the high diversity, corroborated by the Simpson (D) and Shannon (H') indices. From a total of 227 yeasts strains tested, more than 20% were able to withstand peracetic acid concentrations >200 ppm, with emphasis on W. anomalus (300 ppm), W. sergipensis (350 ppm), C. rugopelliculosa (350 ppm), K. marxianus (450 ppm), C. parapsilosis (500 ppm), C. pseudointermedia (500 ppm), W. sorbosivorans (500 ppm), C. boleticola (600 ppm), S. cerevisiae (700 ppm) and C. orthopsilosis (750 ppm). This study adds novel data regarding the occurrence and diversity of yeasts present in FCOJ and their resistance to a chemical compound commonly employed in the sanitization of processing and distribution premises and vehicles. These findings are essential to support the development of measures for proper mitigation of contamination of orange juice towards reducing the risks of spoilage by yeasts during FCOJ transportation/storage or when FCOJ is used as an ingredient.

Using extended Bigelow meta-regressions for modelling the effects of temperature, pH, °Brix on the inactivation of heat resistant moulds.

The management of Heat Resistant Moulds (HRMs) is considered a great challenge for the juice fruit industry. Neosartorya, Byssochlamys and Talaromyces are three out of the main genera isolated from fruit juices that show great resistance to heat treatments. Several inactivation parameters can be found in the literature, however all of them were carried out in specific food matrices and using diverse inactivation methods. Thus, this meta-analysis study synthesizes the thermal resistance parameters of the three HRMs by adjusting extended Bigelow-based meta-regression models to data on inactivation experiments conducted in different liquid media. The meta-analytical data, extracted from publications between 1969 and 2017, was composed of decimal reduction time (D), inactivation method, temperature of inactivation, pH, °Brix, age of spores, and type of medium (model, juice, concentrates). Pooled D* values (D at 90 °C, pH 3.5 and 12° Brix) were estimated for B. fulva (1.95 min; 95% CI: 1.21-3.11 min), Talaromyces (4.03 min; 95% CI: 3.43-4.74 min), Neosartorya (0.5.35 min; 95% CI: 4.10-7.08 min), and B. nivea (10.32 min; 95% CI: 5.81-18.4 min). It was found that increasing the soluble solids in concentrates tends to cause a lower decrease in the heat resistance of Neosartorya and Talaromyces than increasing the soluble solids in model liquid or juices (p = 0.001; 0.012). In general, the screw-capped tubes and three neck round inactivation methods render higher D* values (p < 0.05) than the thermal death tubes, the polyethylene bag and the capillary methods. Spores of Talaromyces (overall zpH = 7.56; 95% CI: 5.13-13.5) and Neosartorya (overall zpH = 7.07; 95% CI: 5.04-10.8) appear to be more thermal sensitive to a decrease in medium pH than spores of Byssochlamys (overall zpH = 4.34; 95% CI: 3.20-6.73). The meta-regression models presented in this study can be valuable for estimating pooled inactivation kinetic parameters to be used by the fruit juice industry in the management of thermal processes and in the determination of shelf-life.

Recent advances on the application of UV-LED technology for microbial inactivation: Progress and mechanism.

Conventional technologies for the inactivation of microorganisms in food products have their limitations, especially changes in quality attributes that have led to quality deterioration, low consumer acceptance, impact on the environment, and potential health hazards (carcinogens). Ultraviolet (UV) light is an emerging promising nonthermal technology employed for microbial inactivation in water, liquid, and solid food products to curtail the limitations above. This review provides an insight into UV light-emitting diodes (UV-LEDs)' potential as an alternative to the traditional UV lamps for microbial inactivation in liquid and solid media. Also, the mechanisms of inactivation of lone and combined UVA-, UVB-, and UVC-LEDs were discussed. The strategies utilized to improve the efficacy between the UV-LED treatments at various wavelengths were summarized. Combining different UV-LEDs treatments at different wavelengths have a synergistic effect and suppression of microbial cell reactivation. The UV-LED-based advanced oxidation processes (AOPs) also have high germicidal action against numerous microorganisms and are efficient for the degradation of micropollutants. Among the UV-LEDs discussed, UVC-LED has the most antimicrobial effect with the most efficient micropollutants decomposition with regards to UV-LED-based AOPs. This review has provided vital information for future application, development, and customization of UV-LED systems that can meet the food and water safety requirements and energy efficiency.

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.

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.

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.

Impact of Unit Operations From Farm to Fork on Microbial Safety and Quality of Foods.

Unit operations modify material properties aiming to produce uniform and high-quality food products with greater acceptance by the increasingly demanding consumers or with longer shelf life and better possibilities of storage and transport. Microorganisms, including bacteria, molds, viruses, and parasites, may have different susceptibilities to unit operations employed during food processing. On-farm (cleaning, selection and classification, cooling, storage, and transport) and on-factory unit operations (heating, refrigeration/freezing, dehydration, modification of atmosphere, irradiation, and physical, chemical, and microbial-based operations) are commonly employed throughout food production chain. The intensity and combination of unit operations along with food composition, packaging, and storage conditions will influence on the dominance of specific microorganisms, which can be pathogenic or responsible for spoilage. Thus, in the context of food safety objective (FSO), the knowledge and the quantification of the effects caused by each step of processing can enable to control and ensure the quality and safety of manufactured 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.

Phenolic acids and flavonoids of peanut by-products: Antioxidant capacity and antimicrobial effects.

Peanut skin (PS) and meal from dry-blanched peanuts (MDBP) were evaluated as sources of phenolic compounds. PS rendered the highest total phenolic content, antioxidant capacity towards ABTS radical cation, DPPH and hydroxyl radicals as well as reducing power. Phenolic acids were present in PS and MDBP whereas proanthocyanidins and monomeric flavonoids were found only in PS as identified by HPLC-DAD-ESI-MSn. Procyanidin-rich extracts prevented oxidation in non-irradiated and gamma-irradiated fish model system. Both extracts inhibited the growth of gram-positive (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Geobacillus stearothermophilus) and gram-negative bacteria (Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli). Regardless of the strain, phenolic acid-rich extracts showed the lowest minimum inhibitory capacity (MIC); therefore presenting higher antibacterial effect. The MIC of phenolic acid-rich extracts (24-49µgphenolics/mL) was higher but comparable to Ampicillin (10µg/mL). Thus, phenolics in PS and MDBP may serve as antioxidants and antimicrobial compounds.