A diagnosis of the microbiological quality of dehydrated bee-pollen produced in Brazil.

UNLABELLED: Bee-pollen is an apicultural product with potential for medical and nutritional applications; therefore, its microbiology quality should be monitored. In this context, the objective of this study was to diagnose the microbiological quality of 45 dehydrated bee-pollen samples collected from November 2011 to December 2013 in nine Brazilian States. All the samples were negative for sulphite-reducing Clostridium spores, Salmonella, coagulase-positive Staphylococcus and Escherichia coli, which are micro-organisms of public health concern. Total aerobic mesophilic micro-organism counts ranged from <10 to 1·10 × 10(4) CFU g(-1) , with psychrotroph counts ranging from <10 to 1·12 × 10(3) CFU g(-1) and total coliforms from <10 to 2·80 × 10(3) CFU g(-1) , while the values for yeasts and moulds were between <10 to 7·67 × 10(3) CFU g(-1) . According to the literature, the microbiota observed in this study were typical; however, it is important to consider that these micro-organisms may cause spoilage and diminish shelf life, reason by which quality control programs should be implemented. SIGNIFICANCE AND IMPACT OF THE STUDY: Contamination of bee-pollen can occur during production, collection and processing, but there are few studies of the microbiological quality of this product. Brazil is an important producer of dehydrated bee-pollen, therefore, a diagnosis of the microbiological status is important to ensure the safety of many consumers. Salmonella sp., genus Clostridium, coagulase-positive Staphylococcus, Escherichia coli and even some yeast species are micro-organisms of public health concern and their presence must be monitored. Furthermore, the determination of spoilage micro-organisms indicates whether the production and the processing practices carried out by beekeepers and warehouses were adequate.

Determination of provitamin A of green leafy vegetables by high performance liquid chromatography and open column chromatography.

The purpose of study was to determine the provitamin A value through beta-carotene analysis of five Brazilian leafy vegetables: carrot leaves (Daucus carota L.), beet leaves (Beta vulgaris L.) "serralha" (Sonchus oleracea L.), mint (Mentha piperita LL.) and celery leaves (Aplum graveolens. L.). Two analysis methods were used: open-column chromatography (OCC) and high performance liquid chromatography (HPLC). Two analysis methods were used: open-column chromatography (OCC) and high performance liquid chromatography (HPLC). Recovery tests were done for both methods and 92% of recovery was obtained for OCC and for HPLC 102%. The provitamin A value obtained for these leaves, using OCC were: 491 RE/100 g for carrot, 1097 for beet, 1390 for "serralha", 1016 for mint and 911 for celery. The results obtained using HPLC were 495 RE/100 g for carrot leaves, 1095 for beet leaves, 1472 for "serralha" leaves, 940 for mint leaves and 908 for celery leaves. We concluded that both methods presented good recoveries, are similar for determination of provitamin A in the leaves and they can be used for routine analysis. These five leaves can be as an inexpensive and easily obtained sources of provitamin A in Brazil.

A comparison of beta-carotene and vitamin A effects on a hepatocarcinogenesis model.

The effects of beta-carotene (beta C) or vitamin A (VA) administration for 8 consecutive weeks were compared in male Wistar rats submitted to the resistant hepatocyte model (RH model) of hepatocarcinogenesis. Animals treated with corn oil (CO), instead of carotenoid or retinoid, served as controls. At the end of the study, beta C treatment resulted in a substantial reduction in the hepatocyte nodule incidence, total number of nodules and in the nodule multiplicity, as well as in the number and size of hepatic gamma-glutamyltranspeptidase (gamma GT)-positive foci. In contrast, animals administered with VA presented a 100% nodule incidence and only a moderate decrease in the total number of hepatocyte nodules. These showed to be in the great majority larger than nodules observed after beta C treatment. Moreover, VA administration resulted in similar number and size of gamma GT-positive foci than controls. In addition, the hepatic concentrations of total VA increased in both, beta C and VA treated animals. However, as expected, increases in the hepatic carotenoid concentrations could be only observed after beta C application. Therefore, changes in the hepatic levels of beta C, and not of VA, resulted in appreciable inhibitory effects on preneoplastic lesions of the liver. The evidence implies that the chemopreventive property of beta C is unrelated to its provitamin A activity.