Optimal concentration of organic solvents to be used in the broth microdilution method to determine the antimicrobial activity of natural products against Paenibacillus larvae

American Foulbrood (AFB) is a bacterial disease, caused by Paenibacillus larvae, that affects honeybees (Apis mellifera). Alternative strategies to control AFB are based on the treatment of the beehives with antimicrobial natural substances such as extracts, essential oils and/or pure compounds from plants, honey by-products, bacteria and moulds. The broth microdilution method is currently one of the most widely used methods to determine the minimum inhibitory concentration (MIC) of a substance. In this regard, the fact that most natural products, due to their lipophilic nature, must be dissolved in organic solvents or their aqueous mixtures is an issue of major concern because the organic solvent becomes part of the dilution in the incubation medium, and therefore, can interfere with bacterial viability depending on its nature and concentration. A systematic study was carried out to determine by the broth microdilution method the MIC and the maximum non inhibitory concentration (MNIC) against P. larvae of the most common organic solvents used to extract or dissolve natural products, i.e. ethanol, methanol, acetonitrile, n-butanol, dimethylsulfoxide, and acidified hydromethanolic solutions. From the MIC and MNIC for each organic solvent, recommended maximum concentrations in contact with P. larvae were established: DMSO 5% (v/v), acetonitrile 7.5% (v/v), ethanol 7.5% (v/v), methanol 12% (v/v), n-butanol 1% (v/v), and methanol-water-acetic acid (1.25:98.71:0.04, v/v/v).Fil: Cugnata, Noelia Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Guaspari, Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Pellegrini, María Celeste. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Fuselli, Sandra Rosa. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Alonso Salces, Rosa Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentin

Prevention and Control of American Foulbrood in South America with Essential Oils: Review

American foulbrood (AFB) is the most severe bacterial disease that affects honey bees, having a nearly cosmopolitan distribution. AFB’s causative agent is Paenibacillus larvae. AFB kills infected honey bee larvae; however, it eventually leads to the collapse of the entire colony when left untreated. The infection takes place by the ingestion of the spores with the food provided by adult worker bees to the larvae. In South America (SA) the disease was first described in 1989 in Argentina, constituting the first sanitary challenge for beekeepers to overcome. Prevention and control measures of AFB in SA countries generally include vigilance for early diagnosis, isolation of apiaries with cases of AFB, and multiplication of healthy colonies with hygienic queens, among others. The extensive use of tetracycline hydrochloride in Argentina has led to the development of resistant P. larvae isolates. In this context, the development of alternative and effective methods for the control and prevention of AFB disease is crucial. Currently, alternative strategies for the prevention and treatment of AFB are being studied, mainly based on essential oils

Detection of virgin olive oil adulteration using low field unilateral NMR

The detection of adulteration in edible oils is a concern in the food industry, especially for the higher priced virgin olive oils. This article presents a low field unilateral nuclear magnetic resonance (NMR) method for the detection of the adulteration of virgin olive oil that can be performed through sealed bottles providing a non-destructive screening technique. Adulterations of an extra virgin olive oil with different percentages of sunflower oil and red palm oil were measured with a commercial unilateral instrument, the profile NMR-Mouse. The NMR signal was processed using a 2-dimensional Inverse Laplace transformation to analyze the transverse relaxation and self-diffusion behaviors of different oils. The obtained results demonstrated the feasibility of detecting adulterations of olive oil with percentages of at least 10% of sunflower and red palm oils

Tempranillo grape extract in transfersomes: A nanoproduct with antioxidant activity

Polyphenols are gaining increasing interest due to their beneficial properties to human health. Grape pomace, the by-product of wine production, is a source of these bioactive compounds. An extract from Tempranillo grape pomace was obtained and characterized qualitatively and quantitatively. The major components found were anthocyanins, flavan-3-ols, and flavonols. To improve the bioavailability of these compounds, the extract was formulated in phospholipid vesicles, namely transfersomes. Spherical unilamellar vesicles around 100 nm each were obtained. The antioxidant activity of both the extract and the transfersomes was evaluated by using colorimetric assays (i.e., DPPH, FRAP, and Folin–Ciocalteu). The cells’ viability and the antioxidant activity were assessed in keratinocytes. The results showed that the extract and the transfersomes had no cytotoxic effects and exerted remarkable antioxidant activity, which was more evident in a vesicle formulation. These findings highlighted the potential of the Tempranillo grape pomace extract and the efficacy of the incorporation into phospholipid vesicles.Fil: Asensio Regalado, Carlos. Universidad del País Vasco; EspañaFil: Alonso Salces, Rosa Maria. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Gallo, Blanca. Universidad del País Vasco; EspañaFil: Berrueta, Luis A.. Universidad del País Vasco; EspañaFil: Era, Benedetta. Università Degli Studi Di Cagliari.; ItaliaFil: Pintus, Francesca. Università Degli Studi Di Cagliari.; ItaliaFil: Caddeo, Carla. Università Degli Studi Di Cagliari.; Itali

Honeys from the Argentine Phytogeographic Provinces Chaqueña and Monte in Catamarca and La Rioja

The characterization of Argentinean honeys from the vegetation units (VUs) of the phytogeographical provinces located in Catamarca and La Rioja was performed with the analysis used for honey quality control: sugar profile, free acidity, pH, electrical conductivity (EC), color and contents of moisture, ash, total soluble solids, and hydroxymethylfurfural (HMF). Honeys were authentic and traceable, and complied with the specifications of national and/or international standards, verifying their blossom origin, high quality, good maturity, and freshness. Honeys from VU-9 and VU-23 presented significantly distinctive physicochemical parameters, evidencing the influence of the flora and pedoclimatic conditions of these VUs. Honeys from VU-23 presented significantly higher contents of glucose and total reducing sugars (F + G), and lower EC, ash contents, fructose/glucose ratio, and concentrations of turanose and maltose than those from VU-9. Honeys from VU-23 in La Rioja also exhibited characteristic lighter colors and lower pH and ºBrix values and turanose amounts; and honeys from VU-9 in La Rioja exhibited highest pH values. Catamarca honeys were characterized by high free acidity and high amounts of turanose, regardless of the VUs. The contents of sugars and total soluble solids, moisture, pH, EC, and color of honeys from Catamarca and La Rioja are published here for the first time. This study contributes to the typification of honeys from these provinces, which will provide them an added value and allow them to access newer markets.Fil: Poliero, Aimará Ayelen. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química. Grupo de Investigación en Ingeniería en Alimentos; ArgentinaFil: Aubone, Ines. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Amadei Enghelmayer, Marisa. Nexco, S.a.; ArgentinaFil: Rosso, Valeria Soledad. Nexco, S.a.; ArgentinaFil: Fuselli, Sandra Rosa. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones en Sanidad Producción y Ambiente. - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Investigaciones en Sanidad Producción y Ambiente; ArgentinaFil: Alonso Salces, Rosa Maria. Universidad Nacional de Mar del Plata. Instituto de Investigaciones En Produccion, Sanidad y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones En Produccion, Sanidad y Ambiente.; Argentin

Vibrational Spectroscopy Coupled to a Multivariate Analysis Tiered Approach for Argentinean Honey Provenance Confirmation

In the present work, the provenance discrimination of Argentinian honeys was used as case study to compare the capabilities of three spectroscopic techniques as fast screening platforms for honey authentication purposes. Multifloral honeys were collected among three main honey-producing regions of Argentina over four harvesting seasons. Each sample was fingerprinted by FT-MIR, NIR and FT-Raman spectroscopy. The spectroscopic platforms were compared on the basis of the classification performance achieved under a supervised chemometric approach. Furthermore, low- mid- and high-level data fusion were attempted in order to enhance the classification results. Finally, the best-performing solution underwent to SIMCA modelling with the purpose of reproducing a food authentication scenario. All the developed classification models underwent to a “year-by-year” validation strategy, enabling a sound assessment of their long-term robustness and excluding any issue of model overfitting. Excellent classification scores were achieved by all the technologies and nearly perfect classification was provided by FT-MIR. All the data fusion strategies provided satisfying outcomes, with the mid- and high-level approaches outperforming the low-level data fusion. However, no significant advantage over the FT-MIR alone was obtained. SIMCA modelling of FT-MIR data produced highly sensitive and specific models and an overall prediction ability improvement was achieved when more harvesting seasons were used for the model calibration (86.7% sensitivity and 91.1% specificity). The results obtained in the present work suggested the major potential of FT-MIR for fingerprinting-based honey authentication and demonstrated that accuracy levels that may be commercially useful can be reached. On the other hand, the combination of multiple vibrational spectroscopic fingerprints represents a choice that should be carefully evaluated from a cost/benefit standpoint within the industrial context.Fil: Damiani, Tito. Universita Degli Studi Di Parma. Departamento de Alimentos y Drogas; ItaliaFil: Alonso Salces, Rosa Maria. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aubone, Inés. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Baeten, Vincent. Walloon Agricultural Research Centre; BélgicaFil: Arnould, Quentin. Walloon Agricultural Research Centre; BélgicaFil: Dall'Asta, Chiara. Universita Degli Studi Di Parma. Departamento de Alimentos y Drogas; ItaliaFil: Fuselli, Sandra Rosa. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Fernández Pierna, Juan Antonio. Walloon Agricultural Research Centre; Bélgic

A Liposomal Formulation to Exploit the Bioactive Potential of an Extract from Graciano Grape Pomace

Antioxidant compounds with health benefits can be found in food processing residues, such as grape pomace. In this study, antioxidants were identified and quantified in an extract obtained from Graciano red grape pomace via a green process. The antioxidant activity of the extract was assessed by the DPPH and FRAP tests, and the phenolic content by the Folin–Ciocalteu test. Furthermore, nanotechnologies were employed to produce a safe and effective formulation that would exploit the antioxidant potential of the extract for skin applications. Anthocyanins, flavan-3-ols and flavanols were the main constituents of the grape pomace extract. Phospholipid vesicles, namely liposomes, were prepared and characterized. Cryo-TEM images showed that the extract-loaded liposomes were predominantly spherical/elongated, small, unilamellar vesicles. Light scattering results revealed that the liposomes were small (~100 nm), homogeneously dispersed, and stable during storage. The non-toxicity of the liposomal formulation was demonstrated in vitro in skin cells, suggesting its possible safe use. These findings indicate that an extract with antioxidant properties can be obtained from food processing residues, and a liposomal formulation can be developed to exploit its bioactive value, resulting in a promising healthy product

Characterization of Argentinian Honeys Based on their Sugar Profiles and Quality Parameters

The honeys from the Argentinian provinces of Buenos Aires, La Rioja,Catamarca and Misiones were characterised by the sugar profile (fructose, glucose,sucrose, turanose, maltose and erlose) and the physicochemical parameters (freeacidity, pH, electrical conductivity (EC), colour and contents of moisture, ash,total soluble solids and hydroxymethylfurfural (HMF)) used for honey qualitycontrol. Authentic and traceable honey samples (n = 572) collected along fiveharvests were analysed using the official analytical methods. All honeys met thespecifications of the national and/or international standards for the evaluatedparameters, which denoted the blossom origin of most honeys, and confirmedtheir high quality, good maturity and freshness. The influence of the flora andthe pedoclimatic conditions of each phytogeographical region on the physicaland chemical properties of honey allowed its characterization. Thus, BuenosAires produced typical lighter honeys, and Misiones and Catamarca, darker ones.Buenos Aires honeys presented particular lower values of pH, EC, ash, HMF andmaltose, and higher concentrations of erlose. Misiones honeys exhibited highervalues of moisture, free acidity, EC and turanose amounts, and lower contentsof fructose, glucose and total soluble solids. La Rioja honeys showed higherpH and ºBrix values; and Catamarca honeys, higher sucrose contents. To theauthors? knowledge, the sugar profiles and several quality parameters of honeysfrom Misiones and Catamarca are here reported for the first time, as well as anyphysical and chemical data on La Rioja honeys.Fil: Poliero, Aimará Ayelen. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Aubone, Ines. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Amadei Enghelmayer, Marisa. No especifíca;Fil: Rosso, Valeria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Müller, Pablo Fernando. Instituto Nuestra Señora de Itatí. Profesorado en Ciencias Agrarias y Protección Ambiental; ArgentinaFil: Fuselli, Sandra Rosa. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Alonso Salces, Rosa Maria. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentin

Vibrational spectroscopy coupled to a multivariate analysis tiered approach for argentinean honey provenance confirmation

In the present work, the provenance discrimination of Argentinian honeys was used as case study to compare the capabilities of three spectroscopic techniques as fast screening platforms for honey authentication purposes. Multifloral honeys were collected among three main honey-producing regions of Argentina over four harvesting seasons. Each sample was fingerprinted by FT-MIR, NIR and FT-Raman spectroscopy. The spectroscopic platforms were compared on the basis of the classification performance achieved under a supervised chemometric approach. Furthermore, low- mid- and high-level data fusion were attempted in order to enhance the classification results. Finally, the best-performing solution underwent to SIMCA modelling with the purpose of reproducing a food authentication scenario. All the developed classification models underwent to a “year-by-year” validation strategy, enabling a sound assessment of their long-term robustness and excluding any issue of model overfitting. Excellent classification scores were achieved by all the technologies and nearly perfect classification was provided by FT-MIR. All the data fusion strategies provided satisfying outcomes, with the mid- and high-level approaches outperforming the low-level data fusion. However, no significant advantage over the FT-MIR alone was obtained. SIMCA modelling of FT-MIR data produced highly sensitive and specific models and an overall prediction ability improvement was achieved when more harvesting seasons were used for the model calibration (86.7% sensitivity and 91.1% specificity). The results obtained in the present work suggested the major potential of FT-MIR for fingerprinting-based honey authentication and demonstrated that accuracy levels that may be commercially useful can be reached. On the other hand, the combination of multiple vibrational spectroscopic fingerprints represents a choice that should be carefully evaluated from a cost/benefit standpoint within the industrial context