Isolation and identification of allergens and biogenic amines of Prosopis juliflora genotypes

Background: Prosopis, or mesquite (Prosopis juliflora (Sw.) DC.), was introduced in Saudi Arabia several decades ago and is heavily used in street, roadside, and park plantations. It shows great adaptation to the prevailing climatic conditions such as high temperature, severe drought, and salinity and spreads naturally in many parts of the Kingdom. This research was conducted to isolate allergen proteins and biogenic amines from the pollen grains of P. juliflora genotypes in Saudi Arabia from two regions, namely Al-Qassim and Eastern regions. Results: The results showed that 18 different allergen proteins were detected in P. juliflora genotypes, with molecular weight ranging from 14 to 97 kDa. Moreover, P. juliflora genotypes from the two studied regions contained eight biogenic amines, namely histamine, tyramine, tryptamine, ß-phenylethylamine, butricine, codapherine, spermidine, and spermine. All genotypes from the Al-Qassim region were found to contain all eight amines, while in the Eastern region, histamine was absent in three genotypes, spermine was absent in six genotypes, and spermidine was absent in three genotypes. Genotypes B23, E20, and E21 had the lowest biogenic amine quantity. Conclusions: All identified proteins from mesquite trees from both regions (Eastern and Al-Qassim) cause allergies in patients who are sensitive to pollen grains. Bioamines, except histamine and tyramine, were recorded at varying concentrations in different genotypes.

Histamina em queijos tipo Minas padräo e prato / Histamine in pratoi and Minas cheeses

Foram avaliados os níveis de histidina livre e histamina em um total de 40 amostras de queijos comerciais dos tipos Prato e Minas padräo, coletado em 4 épocas diversas ao longo de um período de 12 meses. Os resultados revelaram níveis máximos de histidina livre de 46,25 e 33,76mg/100g nos queijos Prato e Minas padräo, respectivamente, enquanto os teores de histamina foram muito reduzidos, com valores máximos de 1,41 e 1,75mg/100g, respectivamente. Bactérias histamina positivas foram isoladas em números reduzidos a partir das amostras, sendo caracterizadas como bactérias lácticas. Cultura pura de linhagem histamina positiva foi inoculada em amostras homogeinizadas e esterilizadas de queijos Prato e Minas padräo, seguido de inoculaçäo a 15º e 30ºC por períodos de 5 e 12 dias. Os resultados, quando comparados aos tratamento-controle, näo revelaram produçäo acentuada de histamina que alcançou níveis máximos de 2,34 e 1,77mg/100g nos queijos Prato e Minas padräo, respectivamente. Conclui-se que estes tipos de queijos oferecem risco muito reduzido de acúmulo de histamina em níveis potencialmente tóxicos ao homem