RESUMEN
The simplest way to eliminate microorganisms in the must/wine is through sulfuration, as it allows the introduction of pure yeast varieties into the must, which guarantees a high-quality wine. However, sulfur is an allergen, and an increasing number of people are developing allergies to it. Therefore, alternative methods for microbiological stabilization of must and wine are being sought. Consequently, the aim of the experiment was to evaluate the effectiveness of ionizing radiation in eliminating microorganisms in must. The sensitivity of wine yeasts, Saccharomyces cerevisiae, S. cerevisiae var. bayanus, Brettanomyces bruxellensis, and wild yeasts to ionizing radiation was com-pared. The effects of these yeasts on wine chemistry and quality were also determined. Ionizing radiation eliminates yeast in wine. A dose of 2.5 kGy reduced the amount of yeast by more than 90% without reducing the quality of the wine. However, higher doses of radiation worsened the organoleptic properties of the wine. The breed of yeast used has a very strong influence on the quality of the wine. It is justifiable to use commercial yeast breeds to obtain standard-quality wine. The use of special strains, e.g., B. bruxellensis, is also justified when aiming to obtain a unique product during vinification. This wine was reminiscent of wine produced with wild yeast.. The wine fermented with wild yeast had a very poor chemical composition, which negatively affected its taste and aroma. The high content of 2-methylbutanol and 3-methylbutanol caused the wine to have a nail polish remover smell.
Asunto(s)
Saccharomyces cerevisiae , Vino , Humanos , Vino/análisis , Microbiología de Alimentos , Fermentación , Fitomejoramiento , AlérgenosRESUMEN
Electrons with energies of 300 keV or lower have the potential to decontaminate the surfaces of various types of food products with minimal loss of quality. The aim of the present work was to determine the thickness of the layer inhabited by microorganisms. The food samples tested were black and white pepper irradiated with 200 keV, 230 keV, 300 keV and 9 MeV beams of electron energy. To determine the depth from the surface which can be inhabited by microorganisms two approaches were tested. The methods used were based on the application of different microbiological recovery techniques and the microbial effectiveness of the irradiation process depending on the energy of the electron beam. It was observed that the layer which microorganisms may contaminate differed for the tested samples it was estimated as being below 100 µm thick for white pepper and about 200 µm for black pepper. The penetration ability was significant in experiments performed, and as a result the electron beam at the lowest levels tested (200 and 230 keV) was found to be insufficient to effectively decontaminate the black pepper samples. The beam of energy 300 keV was found to have a similar microbial inactivation effect as the high energy electron beam (9 MeV).
Asunto(s)
Bacterias/efectos de la radiación , Contaminación de Alimentos/prevención & control , Irradiación de Alimentos/métodos , Piper nigrum/microbiología , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Electrones , Contaminación de Alimentos/análisis , Irradiación de Alimentos/instrumentación , Viabilidad Microbiana/efectos de la radiación , Piper nigrum/efectos de la radiación , Verduras/microbiología , Verduras/efectos de la radiaciónRESUMEN
This study investigated the role of irradiation with a high-energy electron beam in reducing mycotoxin levels of African nutmeg powder (ANP) samples. African nutmeg was procured from a local market in Accra, Ghana, cleaned, milled, packaged and irradiated using electrons of energy 9 MeV at doses of 2, 4, 6 and 8 kGy. Un-irradiated ANP served as a control. Mycotoxin levels of the treated samples were determined using appropriate standard methods. Aflatoxins B1 (AFB1) and B2 (AFB2) as well as ochratoxin A (OTA) were detected in the nutmeg samples. Irradiation significantly (p < 0.05) reduced mycotoxin levels of the ANP with increasing doses. Aflatoxins G1 and G2 were not detected in any of the samples. A dose of 8 kGy was effective in reducing the mycotoxin levels below the permissible limit in food. This suggests that a high-energy electron beam is effective in reducing mycotoxin levels in African nutmeg powder.
RESUMEN
Nanotechnology is one of the fastest developing new areas in science and technology. Ionizing radiation is widely applied for nanostructure synthesis and nanomaterials modification. The ability to fabricate structures with nanometric precision is of fundamental importance to any exploitation of nanotechnology. Nanofabrication involves various lithographies to write extremely small structures. An interesting field of radiation nanotechnological application concerns the development of nano-ordered hydrogels for biosensors. New trends and more precise treatment technology were applied: surface curing and modification, polymer functionalization are good examples of such developments. Patents on application of ionizing radiation in nanotechnology focused on many different approaches to this topic, not only nanoparticles synthesis but also nanostructure modification or functionalization.