Browsing by Author "Dias, Teresa"
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- Application of FTIR-ATR spectroscopy on the bee pollen characterizationPublication . Anjos, O.; Santos, António J.; Dias, Teresa; Estevinho, Letícia M.Bee pollen contains almost all nutrients required by the human organism as well as diverse health-promoting substances. However, its composition and nutritional value greatly depend on the botanical origin. As such, it is importante to develop a rapid and non-expensive methodology that allows studying its characteristics, making labelling more objective and easier. The FTIR-ATR technique was used to predict some nutritional parameters in 126 bee pollen samples. FTIR-ATR spectrum obtained in the region between 4000 and 400 cm−1 with PLS Regression models were used to correlate spectral information with the data obtained using reference methods. In this first approach with pollen samples, good correlation models with appropriate accuracy were obtained for the evaluated parameters with r2 varying from 74.8 to 97% and residual prediction deviation between 2.0 and 5.8. These results suggest that FTIR-ATR may be a useful technique for assessing bee pollen’s composition.
- Influence of the storage conditions (frozen vs dried) in health‐related lipid indexes and antioxidants of bee pollenPublication . Estevinho, Letícia M.; Dias, Teresa; Anjos, O.Following harvest, bee pollen must be submitted to processing in order to maintain properties for consumers’ health insurance. In this study, the changes on the lipid profile, contents of vitamin C, β‐carotene and lycopene of bee pollen samples submitted to two conservation methods (freezing and drying) are evaluated. Eleven fatty acids, eight saturated, one monounsaturated, and two polyunsaturated are quantified. The PUFA/SFA ratio ranges from 1.18 to 3.95 g 100−1 g−1 and is significantly higher in the frozen extracts. On the other hand, the ratio n6:n3 (ranging between 0.36 and 0.86 g 100−1 g−1) did not differ among processing methodologies, for most of the cases. The atherogenicity (AI) and thrombogenecity (TI) indexes are similar among preservation processes and coherent with the found on other health‐promoting foods. The contents of vitamin C, β‐carotene and lycopene are, for all samples, significantly superior in the frozen bee pollen.
- Variation of lipids indexes in pollen with its botanical originPublication . Anjos, O.; Campos, Maria da Graça; Dias, Teresa; Estevinho, Letícia M.Bee pollen is one of nature's healthful food products with promising nutritional and therapeutic properties due to its chemical composition, particularly its protein content, which includes almost all the essential amino acids. Nevertheless the composition in lipids it is not completely known and supposedly will be highly variable depending on the floral origin. As such, this parameter must be ascertained in line with the research for bioactivity [1]. The aim of this work was to evaluate some health-related lipid indexes of bee pollen, namely omega-6/omega-3 fatty acid ratio (n-6/n-3); polyunsaturated fatty acid/saturated fatty acid ratio (PUFA/SAT), atherogenic index (AI) and thrombogenic index (TI) in samples harvested in Portugal. The selected parameters were calculated from the Fatty-Acid Profile, which was determined as previously reported by Bárbara et al. [3]. Bee pollen samples, after harvest, were cleaned and frozen at -20 oC and were codified according the predominant pollen. Figure 1 associates the lipid indexes of the different samples with their botanical origins. n-6/n-3 and PUFA/SAT ratios were in within the limits recommended by World Health Organization (below 4.0 and above 0.45, respectively), suggesting that bee pollen is a good product with the nutritional point of view, with potential beneficial effects for the consumer's health. Also, both AI and TI indexes of this natural product were low, even though this effect depended on bee pollen's botanical origin (Figure 1).