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Abstract: Vapor contact is an alternative when essential oils (EO''s) and microorganisms are placed separately in some sealed environment. The aim of this study was to compare the antifungal efficacy of orange peel EO at selected concentrations, applied either by vapor exposure or direct addition on the growth of Aspergillus flavus. Orange peel EO was obtained from fresh oranges (Citrus sinensis var. Valencia). EO was obtained by vapor distillation, analyzed by means of GC–MS chromatography, and applied to potato-dextrose agar inoculated with A. flavus, using the techniques of direct addition to the agar or by generating EO vapors in airtight containers. Radial growth rate and lag phase were calculated using the Gompertz equation. Main compounds identified in the orange peel EO were: limonene, β-myrcene, β-pinene, α-pinene, as well as citral Z and E; of which, limonene represented 96.62%. The minimum inhibitory concentration for the growth of A. flavus by direct addition was 16,000 mg l−1, while for the vapor contact was 8000 mg of EO l−1 of air. For both studied methods A. flavus growth decreased when increasing EO concentration. Although the effect of orange peel EO direct addition was faster, orange peel EO vapors were more effective, since lower concentrations were required to achieve the same antifungal effect. [Copyright &y& Elsevier]

Abstract: Antimicrobial agents can be incorporated into edible films to provide microbiological stability, since films can be used as carriers of a variety of additives to extend product shelf life and reduce the risk of microbial growth on food surfaces. Addition of antimicrobial agents to edible films offers advantages such as the use of small antimicrobial concentrations and low diffusion rates. The aim of this study was to evaluate inhibition by vapor contact of Aspergillus niger and Penicillium digitatum by selected concentrations of Mexican oregano (Lippia berlandieri Schauer), cinnamon (Cinnamomum verum) or lemongrass (Cymbopogon citratus) essential oils (EOs) added to amaranth, chitosan, or starch edible films. Essential oils were characterized by gas chromatography–mass spectrometry (GC/MS) analysis. Amaranth, chitosan and starch edible films were formulated with essential oil concentrations of 0.00, 0.25, 0.50, 0.75, 1.00, 2.00, or 4.00%. Antifungal activity was evaluated by determining the mold radial growth on agar media inoculated with A. niger and P. digitatum after exposure to vapors arising from essential oils added to amaranth, chitosan or starch films using the inverted lid technique. The modified Gompertz model adequately described mold growth curves (mean coefficient of determination 0.991±0.05). Chitosan films exhibited better antifungal effectiveness (inhibition of A. niger with 0.25% of Mexican oregano and cinnamon EO; inhibition of P. digitatum with 0.50% EOs) than amaranth films (2.00 and 4.00% of cinnamon and Mexican oregano EO were needed to inhibit the studied molds, respectively). For chitosan and amaranth films a significant increase (p<0.05) of lag phase was observed among film concentrations while a significant decrease (p<0.05) of maximum specific growth was determined. Chitosan edible films incorporating Mexican oregano or cinnamon essential oil could improve the quality of foods by the action of the volatile compounds on surface growth of molds. [Copyright &y& Elsevier]

Hurdle technology combining an emerging preservation technique such as low-frequency ultrasound is an alternative for processing juices that are susceptible to suffer a loss of quality due to traditional heat treatments. Predictive microbiology allows evaluation of the effectiveness of preservation techniques and its combinations in order to enhance both food quality and safety. Listeria innocua inactivation by thermo-sonication along with vanillin was investigated. Fermi model ( R= 0.970 ± 0.02) and surface response methodology ( p < 0.05) were utilized in order to evaluate the survival of L. innocua to a multi-target treatment and to predict the interactions of studied techniques, high-intensity/low-frequency ultrasound (20 kHz/400 W) at selected wave amplitudes (60, 75, or 90 μm), temperature (40, 50, or 60 °C), and vanillin (200, 350, or 500 mg/kg). A combination of ultrasound, vanillin, and temperature enhanced L. innocua inactivation as described by Fermi parameters a and t, which decreased as the studied effects increased. A multi-target inactivation effect was observed for a temperature range of 45-55 °C. [ABSTRACT FROM AUTHOR]

The fungal plant infection caused by Colletotrichum gloeosporioides known as anthracnose, affects tropical fruits thus causing low yield and poor fruit quality. The antifungal activity of ethanol and chloroform extracts of different Mexican plants jarilla ( Baccharis salicifolia), tepozan ( Buddleia americana), nanche ( Byrsonima cordata), cinco negritos ( Lantana camara), Mexican oregano ( Lippia berlandieri var. Scanner), and pericon ( Tagetes lucida) against C. gloeosporioides were evaluated by determining the minimum inhibitory concentration (MIC) of the ethanol and chloroform extracts. Subsequently, an antifungal assay was carried out by determining the inhibition of radial growth in PDA plates added with plant extracts. Jarilla, oregano, and pericon MIC values were 400 mg/L for ethanol extracts and 200 mg/L for chloroform extracts. Tepozan, nanche, and cinco negritos showed no antifungal effect. Concerning the inhibition of radial growth, pericon ethanol extract showed an 84% inhibition; chloroform extracts of jarilla, oregano, and pericon showed 88%, 90%, and 95% inhibition, respectively. The ethanol extracts of oregano and jarilla demonstrated to be inhibitory at the reproductive phase of C. gloeosporioides, while their chloroform extracts have a fungistatic effect. [ABSTRACT FROM AUTHOR]

Antimicrobial activity of fractions obtained from Mexican oregano ( Lippia berlandieri Schauer) chloroform extract was tested by growth inhibition against Escherichia coli, Staphylococcus aureus and Bacillus cereus, and antioxidant capacity was tested by inhibition of linoleic acid oxidation. Fractions were obtained by differences in polarity or structure (phenolic and non-phenolic fraction). Gram-positive organisms were more susceptible to Mexican oregano extracts. Fraction 3 (by polarity) and phenolic fractions I, II, III, IV and V were the extracts with higher antimicrobial activity. The non-phenolic fraction had effect against B. cereus. Polarity fraction 5 and phenolic Fraction II had a high antioxidant capacity; a 0.08% concentration of fraction 5 had a similar effect as butylated hydroxytoluene at 0.01% concentration. Fractions of Mexican oregano with different polarity and functional groups had antioxidant and antimicrobial activity and can be used in a variety of applications. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of low-dosage treatment with ultraviolet-C light (19.75 J L-1 for 5 min), mild thermal treatment (40 °C for 5 min), or their combination on the native microflora (mesophiles and moulds plus yeast) and consumer acceptance of orange juice at the beginning and after storage (5 or 22 °C). Results indicated that UV-C light and mild thermal treatments reduce 0.19 ± 0.03 and 0.25 ± 0.02 log cycles (both kinds of microorganisms), respectively. The combination of treatments displays an additive effect against mesophiles (0.47 ± 0.01 log) and moulds plus yeasts (0.42 ± 0.02 log). After 9 days of storage at 5 °C, combined treatment did not present any microbial increases (P > 0.05), while consumer acceptance was similar (P > 0.05) to the fresh orange juice. Although several studies about the use of hurdle technology using UV-C light in orange juice have to be conducted, the results obtained in this study are promising, and they can be used for further studies. [ABSTRACT FROM AUTHOR]

The addition of red cactus pear peel and its mucilage on color, bioactive compounds and antioxidant capacity (AC) of yogurt was investigated. Peel and its mucilage were dried and used for the formulation of different yogurt blends following a constrained mixture design. Color, total phenolic compounds, total flavonoids, total betalains and AC were evaluated in formulated yogurts. An optimization process was conducted thereafter, and the bioactive compounds and AC of this yogurt were evaluated before and after gastrointestinal simulation. Results indicated that cactus pear peel and its mucilage give a nice magenta color to the yogurts, and also increase the bioactive compounds and AC of them. Optimization procedure indicates that yogurt formulated with 5.5% of cactus pear peel and 7.5% of mucilage displays the highest bioactive compounds and AC; moreover, they were significantly increased (p < 0.05) by the simulated gastrointestinal process. [ABSTRACT FROM AUTHOR]

Habanero pepper is a good source of bioactive compounds with antioxidant capacity; however, up to now, some factors for increasing their extraction have not been investigated yet. This research aimed to evaluate the effect of solid‐to‐solvent ratio (1:250, 1:45, and 1:25 w/V), temperature (20, 35, and 50°C), and time (6, 15, and 24 hr) on the extraction of bioactive compounds and antioxidant capacity from habanero pepper following a Box–Behnken design. The optimal extract was evaluated in its capsaicinoids content by HPLC and as an antimicrobial against two foodborne pathogens. The response surface models adequately adjusted (R2 >.75) experimental data of bioactive compounds extraction from habanero pepper in the ranges of the variables proposed. Extract obtained under the optimal conditions (1:250 w/V, 50°C, and 24 hr) contains 1,617.9 mg/100 g and 628.0 mg/100 g of capsaicin and dihydrocapsaicin, respectively, showing a reduction of 1.23 ± 0.14 and 2.37 ± 0.10 log cycles for S. Typhimurium and S. aureus, respectively. Novelty impact statement: Extraction of bioactive compounds from natural sources is currently on the rise. However, regardless the use of traditional or novel extraction technologies is necessary for the evaluation of factors that may affect the yield of bioactive compounds extraction. Habanero pepper is a well‐known source of bioactive compounds with antimicrobial and antioxidant properties. However, until the moment, the effect of factors, such as temperature, time, solid‐to‐solvent ratio, etc., has been scarcely studied. Thus, this study may be a good starting point for future research on the extraction of bioactive compounds from the habanero pepper and find potential applications in food, biotechnological, pharmaceutical, among other industries. [ABSTRACT FROM AUTHOR]

Saffron is derived from the stigmas of the flower Crocus sativus L. The drying process is the most important post-harvest step for converting C. sativus stigmas into saffron. The aim of this review is to evaluate saffron's post-harvest conditions in the development of volatile compounds and its aroma descriptors. It describes saffron's compound generation by enzymatic pathways and degradation reactions. Saffron quality is described by their metabolite's solubility and the determination of picrocrocin, crocins, and safranal. The drying process induce various modifications in terms of color, flavor and aroma, which take place in the spice. It affects the aromatic species chemical profile. In the food industry, saffron is employed for its sensory attributes, such as coloring, related mainly to crocins (mono-glycosyl esters or di-glycosyl polyene). [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the structural, physical, and antifungal characteristics of starch edible films added with nanocomposites and Mexican oregano (Lippia berlandieri Schauer) essential oil (EO). Starch edible films were formulated with Mexican oregano EO (0%, 1%, or 2% v/v) and bentonite or halloysite (2%). Physical properties such as L* (luminosity), hue, film thickness, and O2 and CO2 permeability were determined. Structural analysis was carried out via atomic force microscopy (AFM). Antifungal activity against Aspergillus niger, Fusarium spp., and Rhizopus spp. was evaluated. The addition of EO and nanocomposites reduced luminosity, providing color to the edible films. Film thickness increased through the addition of EO concentration. O2 and CO2 permeability was increased by bentonite/EO films, and for halloysite films, CO2 permeability decreased as EO concentration increased. The addition of EO with both nanocomposites shows an evident morphological change in film structure, decreasing pore density and increasing pore size. In general, Mexican oregano EO added to edible starch films has an adequate fungicidal effect. The most sensitive microorganism tested was A. niger. Edible films added with Mexican oregano EO and nanocomposites show better physical and antifungal properties due to an adequate structural change in the biopolymer matrix. [ABSTRACT FROM AUTHOR]