Validation of hplc methods for analysis of vitamins B1, B2, B6 and niacin naturally present in cereal flours

Complex B vitamins are present in some cereal foods and the ingestion of enriched products contributes to the recommended dietary intake of these micronutrients. To adapt the label of some products, it is necessary to develop and validate the analytical methods. These methods must be reliable and with enough sensitivity to analyze complex B vitamins naturally present in food at low concentration. The purpose of this work is to evaluate, with validated methods, the content of vitamins B1, B2, B6 and niacin in five cereal flours used in food industry (oat, rice, barley, corn and wheat)

Efficiency of the FT-IR ATR spectrometry for the prediction of the physicochemical characteristics of Melipona subnitida honey and study of the temperature’s effect on those properties

The efficiency of ATR FT-IR spectrometry was compared with recommended methodologies for physicochemical parameters of eighteen samples of Melipona subnitida honey. Significant differences were found between the values obtained using those techniques for hydroxymethylfurfural, ash and electrical conductivity. The results for the other parameters did not differ significantly, suggesting that this rapid and nondestructive methodology may predict parameters usually used to assess honeys’ quality. The effects of different storage conditions (room temperature, fridge and freezer) on the quality parameters of the product stored during 12 months were studied. Darkening of the honey was observed, particularly in the fridge and freezer. However, the changes occurring in the honey kept on the fridge were not statistically different from those occurring in the product kept on the freezer, except for free acidity. The results obtained for the honey stored at room temperature, best way to preserve, differed significantly from those obtained for the honey kept under the other conditions

Stability of antioxidants vitamins in bee pollen samples

This study evaluated the stability of vitamins C, E and &#946;-carotene in six samples of bee pollen after their process, and in a one-year period of storage. After the pollen's process, there was a 67.1% increase for vitamin C (p <0.05), an 18.7% loss for vitamin E and 15.6% for &#946;-carotene. Storage in freezer was the most efficient condition for the vitamins conservation; the loss in storage at room temperature (exposed or protected from light) was similar. Vitamin E appears to be better preserved during storage when compared to vitamin C and &#946;-carotene.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Comparação de metodologias para determinação de umidade em amostras de pólen apícola desidratadas

Bee pollen moisture value is one of the quality parameters for this product. Some countries such as Argentina, Brazil, Bulgaria, Poland and Switzerland have bee pollen regulations on quality parameters, but these are not clear regarding which method should be used for moisture determination. The aim of this paper was to compare six methods of moisture determination in dried bee pollen samples. The methods were: conventional oven at 100 °C, vacuum oven at 70 °C, desiccator with sulfuric acid, drying out process with infrared light at 85 °C, lyophilization and Karl Fisher's method. Based on the results, the best methods for moisture determination of bee pollen were the drying process with infrared and the lyophilization, since these have shown lower moisture values.O teor de umidade do pólen apícola constitui um parâmetro de qualidade para este produto. Alguns países como Argentina, Brasil, Bulgária, Polônia e Suíça têm legislação específica quanto aos parâmetros de qualidade do pólen apícola, mas não são claras quanto à recomendação do método a ser utilizado na determinação de umidade. O objetivo deste trabalho foi comparar seis métodos de determinação de umidade do pólen apícola desidratado. Os métodos utilizados foram: estufa convencional a 100 °C, estufa a vácuo a 70 °C, dessecador com ácido sulfúrico, secagem por radiação infravermelha, liofilização e Karl Fisher. De acordo com os resultados obtidos, os melhores métodos para determinação de umidade do pólen apícola foram a secagem por radiação infravermelha e a liofilização, os quais apresentaram menores valores de umidade.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)"Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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

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. 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.The authors are grateful to State of S~ao Paulo Research Foundation (FAPESP) for financial support (FAPESP process 2011/51741-5) and scholarship granted to Adriane Alexandre Machado de Melo (FAPESP process 2013/ 23179-6).info:eu-repo/semantics/publishedVersio

Comparação de métodos de análise para o ácido pantotênico em alimentos

The analysis of pantothenic acid in foods is routinely performed by microbiological methods, which are very tedious and take too long time of well-trained and experienced analyst. The high performance liquid chromatography (HPLC) is an alternative technique for vitamin analysis in foods. In this paper infant formulae were analyzed by HPLC and microbiological methods and the average results obtained were compared statistically. The difference between the two methods showed no statistical difference.A análise do ácido pantotênico em alimentos é realizada de forma rotineira através do método microbiológico, o qual é trabalhoso e demorado. A cromatografia líquida de alta eficiência (CLAE ou HPLC) tem se mostrado um método alternativo para a análise de vitaminas em alimentos. Neste trabalho foram analisadas amostras de fórmulas infantis em pó pelos dois métodos e os resultados médios foram comparados. Através de análise estatística dos resultados observou-se que os dois métodos apresentaram-se equivalentes

Phenolic composition and antioxidant activity assessment of southeastern and south Brazilian propolis

Propolis is a resinous substance collected by honey bees Apis mellifera from several plant sources and used in the hive to seal the walls, to strengthen the ends of the honey comb or embalm dead invaders. The chemical specificity of propolis is directly determined by the variability of the plant origins and by geographical and climatic features of the collection site. The aim of this work was the quality assessment of 16 south and southeast Brazilian propolis samples through the identification and quantification of phenolic compounds using chromatographic and spectroscopic techniques such as HPLC and LC/DAD/ESI-MS n . Generally, the samples presented a phenolic profile related to Brazilian green propolis with origin in Baccharis spp. leaves, where the caffeoylquinic ac id derivatives as well as dihydrokaempferide and artepillin C were the main compounds. Moreover, DPPH • free radical-scavenging activity, reducing power and differential pulse voltammetry were applied to evaluate the antioxidant activity. Differential pulse voltammetry proved to be a rapid and easy tool for the quantification of the total electroactive species present in the samples. The results revealed a richer phenolic composition and higher bioactivity in Minas Gerais samples rather than the southern ones.N. Vale thanks Fundação para a Ciência e Tecnologia (FCT, Portugal) for financial support to Research Unit on Applied Molecular Biosciences, UCIBIO/REQUIMTE, through project UID/Multi/04378/2013, and also for granting Nuno Vale an “Investigador FCT” position (Ref. IF/00092/2014). Thanks to FCT for financial support given to CIMO (UID/AGR/00690/2013). Ligia B. Almeida-Muradian thanks CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) for financial support and Alexandre Bera and Renato Sousa for technical support.info:eu-repo/semantics/publishedVersio

HPLC- MS Flavonoid determination and antioxidant capacity of Brazilian dehydrated bee pollen

Bee-pollen, produced by Apis mellifera bees, is an important source of proteins, lipids, vitamins and minerals for the hive, being considered one of nature's most completely nourishing foods. Its composition may vary according to the geographical region and its quality is influenced by harvest method and processing conditions. Although it has good nutritional components, beepollen contains significant amounts of polyphenols with recognized health benefits, including antioxidant activity. The present study aimed to evaluate the flavonoid composition, using HPLC-MS technique; and the antioxidant activity, using two different methods (DPPH and ORAC), of eight dehydrated bee-pollen samples collected in different Brazilian apiaries. The sample with the highest antioxidant capacity using DPPH method was produced in Rio Grande do Sul State (110.85 mol TE/g) while the sample with the least antioxidant capacity was collected in Bahia State (9.97 mol TE/g). The same sample from Rio Grande do Sul State presented the highest antioxidant capacity using ORAC method (542.00 mol TE/g), while the lowest value was observed in a sample from Mato Grosso State (133.70 mol TE/g). The flavonoid analysis using HPLC-MS revealed the following variations: catechin (0.69 to 0.75 mg/100 g); naringenine (4.57 to 18.36 mg/100 g); rutin (3.36 to 46.80 mg/100 g); quercetin (1.86 to 67.91 mg/100 g) and kaempferol (5.50 to 44.97 mg/100 g). In the sample with the highest antioxidant capacity (Rio Grande do Sul State) was observed 40 peaks in the HPLC-MS, while the samples with the lowest antioxidant capacities the number of peaks were 25 (Mato Grosso State) and 22 (Bahia State); therefore, the variety of compounds may have influenced the antioxidant capacity of the samples.info:eu-repo/semantics/publishedVersio

Presence and stability of B complex vitamins in bee pollen using different storage conditions

This study has the objective of evaluating the stability of B complex vitamins and its vitamers, for a period of 1 year of storage. The pollen samples were stored under room temperature (with and without light) and frozen. The vitamins were quantified by HPLC with fluorescence detection. All proposed vitamins were found in the samples and the dehydration process did not interfere in vitamin content. The variations were (dry basis): 0.59–1.09 mg/100 g (B1); 1.73–2.56 (B2); 6.43–15.34 (PP) and 0.33–0.68 (B6). After 1 year of storage, it can be stated that vitamin B1 concentration remained constant, while for the others, the concentration loss was dependent on time rather than on storage conditions. All samples were considered vitamin B2 sources. The influence of the storage time in the concentrations of vitamin B6 and PP was explained mathematically, through linear regression equations of multivariate analysis