Papers on mycobacteria in food, feed and water, published between 1945 and 2010 and indexed in the database Web of Science (Thomson Reuters), were ranked according to authors, institutions, countries and source titles. The total number of papers on mycobacteria and food, and mycobacteria and water were 1,486 and 1,419, respectively. More than 40% of papers have been published in the last five years. In addition to publications in peer reviewed journals the archives of ProMED-mail and the Rapid Alert System for Food and Feed of the European Union were also searched. It is evident that much attention is being paid to mycobacteria in food, feed and water as they likely pose a public health risk.

To foster their competitive advantage, food firms pay an increasing attention to strategies that tend to distinguish their products from the ones supplied by their competitors, dedicating to this task most of their resources, knowledge and creativity. In such a framework, also the resource water, often seen as an homogenous product, is more and more utilized in the advertisement as an element that increases the quality of the final good. This paper aims at building a model that can explain the observed behaviour in the different food industries and that can give some insights about the future perspectives of the utilization of the water as a differentiation factor. To reach this goal, first we present a survey of the commercials of specific food industries (beverages, pasta, bread, fresh produce), in which the contribute of water to the product is shown. On the basis of empirical evidence, we argue that the propensity to use water as an element of differentiation is greater when greater are the degrees of technological knowledge, the consumers' perceptions, and the importance of the differentiation strategy in that specific industry. Since we expect that these three factors will increase over time, we also conclude that it is rational to experiment a generalized increase of the utilization of water in the commercials of food products. We also recommend to extend the analysis testing the results using a quantitative approach | Per effetto dell'aumento della competizione sui mercati nazionali e internazionali, l'industria alimentare è spinta a dedicare una crescente attenzione alle strategie di differenziazione. A tal fine, essa impiega gran parte delle risorse, delle conoscenze e della creatività a disposizione. In un tale contesto, anche l'acqua, una risorsa spesso interpretata come bene altamente omogeneo, risulta sempre più utilizzata nelle campagne promozionali dei prodotti alimentari per spiegare la maggiore qualità degli stessi. Il presente contributo ha l'intento di costruire un modello esplicativo di questi comportamenti tale da offrire, al contempo, indicazioni prospettiche circa il ruolo dell'acqua come elemento di differenziazione. Analizzando le pubblicità di alcuni specifici prodotti (bevande, pasta, pane, ortofrutta fresca), si argomenta che la propensione all'utilizzo dell'acqua come fattore di differenziazione in un determinato comparto alimentare è direttamente proporzionale al livello delle conoscenze tecnologiche, alla percezione del consumatore e alla rilevanza della strategia di differenziazione in quello stesso comparto. Considerando che, nel tempo, ciascuna delle tre determinanti è destinata a sperimentare un trend positivo, è lecito attendersi anche un crescente riferimento al contributo della risorsa acqua all'interno dei messaggi pubblicitari. L'impostazione prevalentemente teorica del presente contributo induce a considerare particolarmente interessante l'ipotesi di testare i risultati mediante un approccio prettamente quantitativo

El propósito de esta investigación fue determinar el perfil microbiológico de alimentos de baja actividad de agua (Aw) y a su vez conocer el comportamiento de Salmonella en estos productos. Frutos secos (nueces y cacahuetes), frutas deshidratadas (pasas y jitomates secados al sol) y muestras de chocolate. Se recolectaron 350 muestras de productos vendidos a granel en mercados de la ciudad de Querétaro. Se cuantificó el contenido de bacterias mesófilas aerobias (BMA), coliformes totales (CT), Escherichia coli, hongos y levaduras, así como la detección por métodos convencionales, de Salmonella enterica y Staphylococcus aureus. Adicionalmente, se realizó la estandarización de una técnica de detección molecular para norovirus en muestras de cacahuates, nueces, pasas y jitomate secado al sol. Los valores de las medianas de los microorganismos indicadores en los cinco productos oscilaron entre 3.1 a 5.2 Log UFC/g para BMA, 0.6-1.2 Log NMP/g para CT, 0.5-0.9 Log NMP/g para E. coli, 1.7-2.4 Log UFC/g para los hongos, 2.0-2.8 Log UFC/g para levaduras levaduras. En ninguna muestra se detectó S. aureus. Por el contrario la presencia de Salmonella de detectó en cacahuates (31 %), nueces (40 %), pasas (30 %), tomate secado al sol (56 %) y chocolate (26 %). El método que resultó efectivo para la detección de Norovirus Murino (MNV-1) consistió en extracción de RNA seguida por RT-PCR; se lograron detectar concentraciones de 2.6, ~0.6, <1 y <1 Log PFU/g en cacahuates, nueces, tomates secados al sol y pasas. | The purpose of this investigation was to determine the microbiological profile of low water activity food items and to know the surveillance of Salmonella in these products. Nuts (pecans and peanuts), dehydrated fruits (raisins and sun-dried tomatoes) and chocolate samples (a total of 350) sold in bulk were collected in city markets. Aerobic Plate Count (APC), Coliforms (TC), E. coli, molds and yeasts quantifications and Salmonella spp. and Staphylococcus aureus detection were carried out by conventional methods. In addition the standardization of a molecular detection technique for norovirus from peanuts, pecans, raisins and sun dried tomato samples was carried out. For the determination of indicator microorganisms the medians observed for the five products are between the values 3.1-5.2 Log CFU/g for APC, 0.6-1.2 Log MPN/g for TC, 0.5-0.9 Log MPN/g for E. coli, 1.7-2.4 Log CFU/g for molds, 2.0-2.8 Log CFU/g for yeasts; there was no detection of positive thermonuclease S. aureus in any sample. Salmonella spp was detected in all the analyzed products: peanuts 31 %, pecans 40 %, raisins 30 %, sun-dried tomato 56 %, and chocolate 26 %. RNA extraction followed by RT-PCR was able to detect the minimum MNV-1 concentrations: peanuts and pecans up to 2.6 Log PFU/g and up to ~0.6 Log PFU/g, respectively. Sun-dried tomatoes showed detection to <1 Log PFU/g and raisins to <1 Log PFU/g.

There has been developed a two-stage method for cooling jars with preserved food after sterilization. The first stage comprises cooling preserves up to t 75-80 deg. C in the air flow, the air velocities being 2.75, 3.7, 4.8, and 5.8 m/sec. The time of cooling reduced as the air velocity increases to be 11, 9, 8.5 and 8 min, respectively. The average speed of cooling gradually increases from 1.82 deg. C/min to 2.5 deg. C/min. The second stage comprises continuing cooling to apply a water film of 60-65 deg. C to the jar surface at 5-10 sec interval. During the process a jar is with a certain frequency is overturned down from the bottom to the cap. The average speed of cooling product is 3.33 deg. C/min at cooling air velocity of 2.75 m/sec and it is gradually increasing to reach 5.4 deg. C/min. Experimentally range of optimum cooling air velocities has been determined to be 4.8-5.8 m/sec, cooling time being decreased by 0.6 min only. A mathematical model has been has been developed describing the two-stage air and water vaporizing cooling time of stewed fruit jars depending on some factors. Relative error in comparing target values with experimental values did not exceed 8%. The developed method is recommended to be used at food canning industry enterprises and for designing continuously operating devices. | Разработан двухэтапный способ охлаждения банок с консервированными продуктами после стерилизации. На первом этапе (до t 75-80 град. С) охлаждение консервов производят в потоке атмосферного воздуха при различных скоростях охлаждающего воздуха – 2,75; 3,7; 4,8 и 5,8 м/с. Продолжительность охлаждения с увеличением скорости охлаждающего воздуха снижается и составляет соответственно 11,0; 9,0; 8,5 и 8,0 мин. При этом средняя скорость охлаждения продукта постепенно увеличивается с 1,82 град. С/м до 2,5 град. С/мин. На втором этапе охлаждение продолжается с нанесением на поверхность банки водяной пленки температурой 60-65 град. С с интервалом 5-10 с, при этом в процессе охлаждения банку с определенной частотой переворачивают с донышка на крышку. Средняя скорость охлаждения продукта составляет 3,33 град. С/мин при скорости охлаждающего воздуха 2,75 м/с и постепенно увеличивается, достигая 5,4 град. С/мин. Экспериментально определен интервал оптимальных скоростей охлаждающего воздуха (4,8-5,8 м/с), при котором продолжительность процесса охлаждения сокращается всего на 0,6 мин. Составлена математическая модель, описывающая продолжительность двухэтапного воздушно-водоиспарительного охлаждения банок с компотами в зависимости от ряда факторов. Относительная погрешность при сопоставлении расчетных значений с опытными не превышала 8%. Разработанный способ рекомендуется для применения на предприятиях консервной промышленности и при проектировании аппаратов непрерывного действия.