Thermal inactivation of Alicyclobacillus acidoterrestris spores in fruit product processing

Alicyclobacillus acidoterrestris spores were recently proposed to be used as design criterion for thermal processes of acid fruit products. This microorganism has been found in commercial pasteurized acid fruit juices, such as orange and apple. Although being non-pathogenic and not easy to detect visually, it is responsible for off-flavours development. On the other hand, the first thermal inactivation kinetic studies confirmed that these spores are much more resistant than the usual spoilage microorganisms in acid foods. Therefore, in 2000 it was firstly proposed to be used in the design of hot-filling and continuous pasteurization conditions of a tropical fruit pulp and juice, respectively. This work presents a critical review on inactivation kinetics of Alicyclobacillus acidoterrestris spores. The available studies were obtained under thermal treatments, and studied the effects of temperature, pH and soluble solids. Those effects were quantified in terms of decimal reduction time (first order model) and z-values (Bigelow model). Furthermore, they were obtained under isothermal conditions. Future challenges in this field are to quantify the inactivation kinetics behaviour under dynamic conditions, using thermal and non-thermal treatments, such as ozonation, ultrasonication or high pressure. These alternative treatments have the advantage of minimizing quality attributes degradation and improving products. Moreover, predictive microbiology skills are suggested as a valuable tool for process design and optimization

Calcific uraemic arteriolopathy - A mini-review

Calcific Uraemic Arteriolopathy (CUA) or calciphylaxis, is a thrombotic disorder of skin and subcutaneous tissue which typically presents with painful purpuric nodules that may progress to necrotic ulcers, and is a severe, life-threatening condition. CUA is an uncommon clinical entity that affects mostly haemodialysis (HD) patients. Although the process of vascular calcification was initially thought to be the result of a passive deposition of calcium-phosphate crystals, current knowledge suggests a distinct mechanism, including cellular activity with differentiation of vascular smooth muscle cells (VSMCs) into chondrocyte as well as osteoblast-like cellular phenotypes and deficiencies in calcification inhibitors. Although multiple studies suggest a potential relationship between warfarin and CUA, larger prospective studies are needed in order to better evaluate this association, and randomised controlled trials are needed to assess the benefit of distinct interventions in this setting. In this article the topic of CUA is reviewed based on a clinical case of a 65-year-old man undergoing haemodialysis, who underwent an aortic valve replacement one year earlier, receiving a mechanical heart valve, and who has been under warfarin therapy since the

Listeriosis during pregnancy: a public health concern

Listeria was first described in 1926 by Murray, Webb, and Swann, who discovered it while investigating an epidemic infection among laboratory rabbits and guinea pigs. The role of Listeria monocytogenes as a foodborne pathogen was definitively recognized during the 1980s. This recognition was the consequence of a number of epidemic human outbreaks due to the consumption of contaminated foods, in Canada, in the USA and in Europe. Listeriosis is especially severe in immunocompromised individuals such as pregnant women. The disease has a low incidence of infection, although this is undeniably increasing, with a high fatality rate amongst those infected. In pregnant women listeriosis may cause abortion, fetal death, or neonatal morbidity in the form of septicemia and meningitis. Improved education concerning the disease, its transmission, and prevention measures for immunocompromised individuals and pregnant women has been identified as a pressing need.info:eu-repo/semantics/publishedVersio

Inactivation of Alicyclobacillu acidoterrestris in apple juice under ultraviolet irradiation treatments

Heat processing is the most commonly used treatment for microbial inactivation. However, temperature may have adverse effects on sensory and nutritional attributes of foods. Non-thermal technologies have received increasing attention for preservation of beverages, due to their potential for inactivating spoilage and pathogenic microorganisms. In addition, they can help minimizing quality losses, namely flavour, colour and nutritional value. Ultraviolet-C radiation (UV-C) is widely used as an alternative strategy to control microorganism in food products. Alicyclobacillus acidoterrestris is a thermo-acidophilic, non-pathogenic and spore-forming bacterium, able to grow at low pH (3.0–3.5) and high temperatures (50–70 °C). It has been considered a new type of spoilage bacterium, with important potential spoilage concern for hot-fill fruit and fruit juices. The main objective of this work was to study the influence of UV-C radiation treatments with seven different intensities (0.32, 0.86, 2.59, 5.59, 8.45, 11.50 and 13.44 W/m2) on A. acidoterrestris inactivation in apple juices. Commercial juices were artificially inoculated with bacterium, with initial loads around 107 CFU/mL. They were then exposed to UV-C radiation and the treatment impact on microbial loads was assessed throughout exposure times. Results showed that the log-survival of A. acidoterrestris decreased linearly with treatment time, for all intensities tested. A decimal reduction time at a given UV-C intensity was estimated by fitting a first order kinetic model to experimental data. When the most severe intensity was used (i.e., 13.44 W/m2), the number of spores decreased drastically (around 5-log reduction, which attains US Food and Drug Administration requirements) after 8 min of treatment. For the remaining UV-C intensities, this inactivation was achieved for higher exposure times. Overall it can be concluded that UV-C radiation is a promising treatment with a drastic impact on the loads of A. acidoterrestris in apple juices, especially when high intensities are used