Chemical Composition of Volatile and Extractive Components of Canary (Tenerife) Propolis.

The vegetation of the Canary Islands is characterized by a large number of endemic species confined to different altitudinal levels. It can be assumed that these circumstances determine the characteristic features of the chemical composition of local beekeeping products, including propolis. We report, for the first time, the chemical composition of propolis from Tenerife (Canary Islands). The volatile emissions of three propolis samples collected from different apiaries are represented by 162 C1-C20 compounds, of which 144 were identified using the HS-SPME/GC-MS technique. The main group of volatiles, consisting of 72 compounds, is formed by terpenoids, which account for 42-68% of the total ion current (TIC) of the chromatograms. The next most numerous groups are formed by C6-C17 alkanes and alkenes (6-32% TIC) and aliphatic C3-C11 carbonyl compounds (7-20% TIC). The volatile emissions also contain C1-C6 aliphatic acids and C2-C8 alcohols, as well as their esters. Peaks of 138 organic C3-C34 compounds were recorded in the chromatograms of the ether extracts of the studied propolis. Terpene compounds form the most numerous group, but their number and content in different samples is within very wide limits (9-63% TIC), which is probably due to the origin of the samples from apiaries located at different altitudes. A peculiarity of the chemical composition of the extractive substances is the almost complete absence of phenylcarboxylic acids and flavonoids, characteristic of Apis mellifera propolis from different regions of Eurasia and North America. Aromatic compounds of propolis from Tenerife are represented by a group of nine isomeric furofuranoid lignans, as well as alkyl- and alkenyl-substituted derivatives of salicylic acid and resorcinol.

Genetic algorithm applied to simultaneous parameter estimation in bacterial growth.

Several mathematical models have been developed to understand the interactions of microorganisms in foods and predict their growth. The resulting model equations for the growth of interacting cells include several parameters that must be determined for the specific conditions to be modeled. In this study, these parameters were determined by using inverse engineering and a multi-objective optimization procedure that allows fitting more than one experimental growth curve simultaneously. A genetic algorithm was applied to obtain the best parameter values of a model that permit the construction of the front of Pareto with 50 individuals or phenotypes. The method was applied to three experimental data sets of simultaneous growth of lactic acid bacteria (LAB) and Listeria monocytogenes (LM). Then, the proposed method was compared with a conventional mono-objective sequential fit. We concluded that the multi-objective fit by the genetic algorithm gives superior results with more parameter identifiability than the conventional sequential approach.

Mechanistically Inspired Kinetic Approach to Describe Interactions During Co-Culture Growth of Carnobacterium maltaromaticum and Listeria monocytogenes.

Lactic acid bacteria and Listeria monocytogenes are psychotropic organisms that can grow and compete in food such as lightly preserved fishery products. Predictive microbiology is nowadays one of the leading tools to assess the behavior of bacteria in food and to predict food spoilage. Mathematical models can be used to predict the growth, inactivation or growth probability of bacteria. Currently, the efforts in microbial modeling are oriented towards extrapolation of results beyond experiments in order to predict the growth of interacting microorganisms and develop new food preservation processes. In the present work, a model combining both heterogeneous population and quasi-chemical approaches to describe the different phases of the bacterial growth curve is presented. The model was applied to both monoculture and co-culture cases of lactic acid bacteria, Carnobacterium maltaromaticum H-17, and two Listeria monocytogenes strains in a raw fish extract. It is a highlight that our model includes novel inhibition reactions due to the accumulation of metabolites, and a general equation to take into account the effect of chemical compounds during the lag or physiological adaptation phase of the cells. Our results show that the proposed model can accurately describe the experimental data when the curve shape is a sigmoid, and when it presents a maximum. Besides, the parameters have biological interpretability since the model is mechanistically inspired.

Microbiological and physicochemical analysis of yateí (Tetragonisca angustula) honey for assessing quality standards and commercialization / Análisis microbiológico y fisicoquímico de la miel de yateí (Tetragonisca angustula) para la evaluación de estándares de calidad y comercialización

Due to the interest in the production and trading of yateí (Tetragonisca angustula) honey in the province of Misiones, Argentina, in this work we assessed microbiological and physicochemical parameters in order to contribute to the elaboration of standards for quality control and promote commercialization. Results showed that yateí honey samples had significantly different microbiological and physicochemical characteristics in comparison to established quality standards for Apis mellifera honey. Thus, we observed that values for pH (3.72), glucose (19.01 g/100 g) and fructose (23.74 g/100 g) were lower than A. mellifera quality standards, while acidity (79.42 meq/kg), moisture (24%), and mould and yeast count (MY) (3.02 log CFU/g) were higher. The acid content was correlated with glucose (R²=0.75) and fructose (R²=0.68) content, and also with mould and yeast counts (R²=0.45) to a lesser extent. The incidence of microorganisms in yateí honey samples reached 42.85% and 39% for Clostridium sulfite-reducers and Bacillus spp., respectively. No C. botulinum or B. cereus cells were detected. Enterococcus spp. and Staphylococcus spp. incidence was similar (ca. 7.14%), whereas Escherichia coli and Salmonella spp. were not detected. We conclude that the microbiological and physicochemical properties of yateí honey are different from those of A. mellifera honey; hence, different quality standards could be implemented to promote its commercialization.

Debido al interés en la producción y comercialización de la miel de yateí (Tetragonisca angustula) en la provincia de Misiones, Argentina, en este trabajo se evaluaron parámetros microbiológicos y fisicoquímicos con el fin de contribuir con la elaboración de normas para el control de calidad y promover su comercialización. Los resultados demostraron que los parámetros analizados en esta miel (n = 28) diferían significativamente de los valores aceptables establecidos para la miel de Apis mellífera. En comparación, se observó que los valores de pH (3,72) y de concentración de glucosa (19,01 g/100 g) y fructosa (23,74 g/100 g) eran más bajos, mientras que los valores de acidez (79,42 meq/kg) y humedad (24 %), al igual que el recuento de hongos y levaduras (HyL) (3,02 log UFC/g), eran más altos. La acidez mostró una correlación inversamente proporcional con el contenido de glucosa (R² = 0,75) y fructosa (R² = 0,68), y directamente proporcional con el recuento de HyL, aunque en este caso la correlación fue menor (R² = 0,45). En lo que respecta a los parámetros microbiológicos, se observó 42,85 % de Clostridium sulfito-reductores y 39 % de Bacillus spp., y no se detectó presencia de C. botulinum ni de B. cereus. Enterococcus spp. y Staphylococcus spp. se encontraron en una proporción similar (ca. 7,14 %), mientras que Escherichia coli y Salmonella spp. no fueron detectados. Concluimos que las propiedades microbiológicas y fisicoquímicas de la miel de yateí difieren de las de la miel de A. mellifera, por lo cual sería oportuno establecer normas de calidad diferentes para facilitar su comercialización.

Microbiological and physicochemical analysis of yateí (Tetragonisca angustula) honey for assessing quality standards and commercialization / Análisis microbiológico y fisicoquímico de la miel de yateí (Tetragonisca angustula) para la evaluación de estándares de calidad y comercialización

Due to the interest in the production and trading of yateí (Tetragonisca angustula) honey in the province of Misiones, Argentina, in this work we assessed microbiological and physicochemical parameters in order to contribute to the elaboration of standards for quality control and promote commercialization. Results showed that yateí honey samples had significantly different microbiological and physicochemical characteristics in comparison to established quality standards for Apis mellifera honey. Thus, we observed that values for pH (3.72), glucose (19.01 g/100 g) and fructose (23.74 g/100 g) were lower than A. mellifera quality standards, while acidity (79.42 meq/kg), moisture (24%), and mould and yeast count (MY) (3.02 log CFU/g) were higher. The acid content was correlated with glucose (R²=0.75) and fructose (R²=0.68) content, and also with mould and yeast counts (R²=0.45) to a lesser extent. The incidence of microorganisms in yateí honey samples reached 42.85% and 39% for Clostridium sulfite-reducers and Bacillus spp., respectively. No C. botulinum or B. cereus cells were detected. Enterococcus spp. and Staphylococcus spp. incidence was similar (ca. 7.14%), whereas Escherichia coli and Salmonella spp. were not detected. We conclude that the microbiological and physicochemical properties of yateí honey are different from those of A. mellifera honey; hence, different quality standards could be implemented to promote its commercialization.(AU)

Debido al interés en la producción y comercialización de la miel de yateí (Tetragonisca angustula) en la provincia de Misiones, Argentina, en este trabajo se evaluaron parámetros microbiológicos y fisicoquímicos con el fin de contribuir con la elaboración de normas para el control de calidad y promover su comercialización. Los resultados demostraron que los parámetros analizados en esta miel (n = 28) diferían significativamente de los valores aceptables establecidos para la miel de Apis mellífera. En comparación, se observó que los valores de pH (3,72) y de concentración de glucosa (19,01 g/100 g) y fructosa (23,74 g/100 g) eran más bajos, mientras que los valores de acidez (79,42 meq/kg) y humedad (24 %), al igual que el recuento de hongos y levaduras (HyL) (3,02 log UFC/g), eran más altos. La acidez mostró una correlación inversamente proporcional con el contenido de glucosa (R² = 0,75) y fructosa (R² = 0,68), y directamente proporcional con el recuento de HyL, aunque en este caso la correlación fue menor (R² = 0,45). En lo que respecta a los parámetros microbiológicos, se observó 42,85 % de Clostridium sulfito-reductores y 39 % de Bacillus spp., y no se detectó presencia de C. botulinum ni de B. cereus. Enterococcus spp. y Staphylococcus spp. se encontraron en una proporción similar (ca. 7,14 %), mientras que Escherichia coli y Salmonella spp. no fueron detectados. Concluimos que las propiedades microbiológicas y fisicoquímicas de la miel de yateí difieren de las de la miel de A. mellifera, por lo cual sería oportuno establecer normas de calidad diferentes para facilitar su comercialización.(AU)

Microbiological and physicochemical analysis of yateí (Tetragonisca angustula) honey for assessing quality standards and commercialization.

Due to the interest in the production and trading of yateí (Tetragonisca angustula) honey in the province of Misiones, Argentina, in this work we assessed microbiological and physicochemical parameters in order to contribute to the elaboration of standards for quality control and promote commercialization. Results showed that yateí honey samples had significantly different microbiological and physicochemical characteristics in comparison to established quality standards for Apis mellifera honey. Thus, we observed that values for pH (3.72), glucose (19.01 g/100g) and fructose (23.74 g/100g) were lower than A. mellifera quality standards, while acidity (79.42 meq/kg), moisture (24%), and mould and yeast count (MY) (3.02 log CFU/g) were higher. The acid content was correlated with glucose (R2=0.75) and fructose (R2=0.68) content, and also with mould and yeast counts (R2=0.45) to a lesser extent. The incidence of microorganisms in yateí honey samples reached 42.85% and 39% for Clostridium sulfite-reducers and Bacillus spp., respectively. No C. botulinum or B. cereus cells were detected. Enterococcus spp. and Staphylococcus spp. incidence was similar (ca. 7.14%), whereas Escherichia coli and Salmonella spp. were not detected. We conclude that the microbiological and physicochemical properties of yateí honey are different from those of A. mellifera honey; hence, different quality standards could be implemented to promote its commercialization.

Microbiological and physicochemical analysis of yateí (Tetragonisca angustula) honey for assessing quality standards and commercialization. / Microbiological and physicochemical analysis of yateí (Tetragonisca angustula) honey for assessing quality standards and commercialization.

Due to the interest in the production and trading of yateí (Tetragonisca angustula) honey in the province of Misiones, Argentina, in this work we assessed microbiological and physicochemical parameters in order to contribute to the elaboration of standards for quality control and promote commercialization. Results showed that yateí honey samples had significantly different microbiological and physicochemical characteristics in comparison to established quality standards for Apis mellifera honey. Thus, we observed that values for pH (3.72), glucose (19.01 g/100g) and fructose (23.74 g/100g) were lower than A. mellifera quality standards, while acidity (79.42 meq/kg), moisture (24

), and mould and yeast count (MY) (3.02 log CFU/g) were higher. The acid content was correlated with glucose (R2=0.75) and fructose (R2=0.68) content, and also with mould and yeast counts (R2=0.45) to a lesser extent. The incidence of microorganisms in yateí honey samples reached 42.85

and 39

for Clostridium sulfite-reducers and Bacillus spp., respectively. No C. botulinum or B. cereus cells were detected. Enterococcus spp. and Staphylococcus spp. incidence was similar (ca. 7.14

), whereas Escherichia coli and Salmonella spp. were not detected. We conclude that the microbiological and physicochemical properties of yateí honey are different from those of A. mellifera honey; hence, different quality standards could be implemented to promote its commercialization.