VALORIZAÇÃO DE RESÍDUOS DA INDÚSTRIA FRUTÍCOLA

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A multivariate approach based on physicochemical parameters and biological potential for the botanical and geographical discrimination of Brazilian bee pollen

Publication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Freitas, Alex da Silva; Barth, Ortrud M.; Almeida-Muradian, Ligia Bicudo

Fifty six Brazilian bee pollen samples were characterised, and their botanical and geographical origins were studied. The samples were also classiﬁed based on physicochemical and biological properties. The characterisation was done using Soxhlet extraction and micro-Kjeldahl methods, ashing at 550°C, transmittance, microscopy, spectrophotometry, inductively coupled plasma optical emission spectrometry and high-performance liquid chromatography. As expected, the values of proteins (7.9–32.2g/100g), lipids (3.2–13.5g/100g), ash (1.9–3.6g/100g), carbohydrates (54.9–82.8g/100g), K (3.4–9.8g/kg), Ca (0.9–4.1g/kg), Mg (0.6–2.4g/kg), Fe (46–1180mg/kg), Na (20–374mg/kg), Mn (25–215mg/kg), Zn (30–101mg/kg), Cu (7.4–19.7mg/kg), total phenolics (6.5–29.2mgGAE/g)and ﬂavonoids(0.3–17.5mgQE/g)as well as the phenolic proﬁles varied among the samples. In general, the products had high antioxidant capacity (ORAC: 133–563 μmol TE/g; DPPH: 9.4–155μmolTE/g) and the antimicrobial capacity varied according to the sample and microorganism tested. The instrumental colour parameters could be used as indicators of some minerals. Based on multivariate approaches, bee pollen from Southern Brazil seemed to have a higher biological potential, whereas products from the Northeast region had higher calcium and magnesium levels. Similarities were identiﬁed in bee pollen containing C. nucifera or Brassica, and monoﬂoral bee pollen seemed to have higher mineral content than heteroﬂoral bee pollen.

2018Journal article

Open access

Potential of Portuguese vine shoot wastes as natural resources of bioactive compounds

Publication . Moreira, Manuela M.; Barroso, M. Fátima; Porto, João Vasconcellos; Ramalhosa, M.J.; Švarc-Gajić, Jaroslava; Estevinho, Leticia M.; Morais, Simone; Delerue-Matos, Cristina

Since annually a high amount of wastes is produced in vine pruning, the aimof this studywas to evaluate the potential of vine shoots fromtwo Portuguese grape varieties (Touriga Nacional - TNand Tinta Roriz - TR) to be used as a natural source of phenolic compounds. To reach this goal, three techniques were explored, namely microwave-assisted extraction (MAE), subcritical water extraction (SWE) and conventional extraction (CE). The phenolic composition of the extracts, antioxidant and biological activities were evaluated by spectrophotometry and chromatography. MAE and SWE produced the highest concentrated extracts. TR vine shoot variety had the highest antioxidant activity and total phenolic (32.1±0.9mggallic acid equivalents/g dry sample), as well as flavonoid content (18.7±1.2mg epicatechin equivalents/g dry sample). For the first time, the biological activity of the vine shoot extracts was tested. Results demonstrated that all of them had antimicrobial potential against different bacteria and yeasts, and the ability of inhibiting α-amylase and acetylcholinesterase enzymes, with MAE TR extracts being the most efficient. HPLC analysis enabled the identification of different phenolic compounds, with gallic acid, catechin, myricetin and kaempferol-3-O-rutinoside being the main contributors to the phenolic composition. Portuguese vine shootwastes could serve as easily accessible source of natural antioxidants for the food or pharmaceutical industries.

2018Journal article

Open access

Phenolic profile and antioxidant capacity from 56 brazilian dehydrated bee-pollen

Publication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Almeida-Muradian, Ligia Bicudo

Bee-pollen is a food produced by bees from the flower pollen, to be a source of proteins, lipids, vitamins and minerals for the hive [1]. Its composition varies according to the region where it is produced, and its quality is influenced by the collection and processing conditions [2, 3]. Besides nutritional substances, bee-pollen contains significant amounts of polyphenols with recognized health benefits, including antioxidant activity [4]. The present study aimed to evaluate the polyphenolic profile and antioxidant activity of 56 dehydrated bee-pollen samples by high performance liquid chromatography and in vitro assays. Bee-pollens samples, collected during November 2011 to December 2013 from apiaries located in different Brazilian regions, were extracted with stirring for 30 minutes with ethanol 70% at 70 ºC and analyzed. The total phenolic content ranged from 6.5 ± 0.2 to 29.2 ± 0.3 mg gallic acid equivalent/g dry sample and flavonoid content ranged from 0.35 ± 0.01 to 17.5 ± 0.1 mg quercetin equivalent/g dry sample. The antioxidant activity assays, with values of 9.4 ± 0.4 to 155 ± 5 mol Trolox equivalent/g dry sample for DPPH and 133 ± 2 to 563 ± 15 mol TE/g for ORAC methods, revealed the antioxidant capacity of bee-pollen extracts. Regarding, the characterization of the phenolic composition from the several extracts by HPLC-PAD it was possible to observe that rutin, quercetin and vanillic acid were the main phenolic compounds found in the Brazilian dehydrated bee-pollen analyzed. On the other hand, caffeic acid was found in less amounts in the majority of samples studied. Among the identified polyphenols, only quercetin seems to have influenced positively in the antioxidant capacity of the samples. The Pearson’s Correlation analysis indicated high correlation between quercetin and ORAC values (r=0.6570, p=0.000) and medium correlation between quercetin and DPPH values (r=0.4873, p=0.000). In conclusion, bee-pollen characteristics vary according to the botanical origin and the Brazilian region where the sample was produced. This is a product with high antioxidant potential, therefore other tests, especially bioavailability assays, should be performed.

2015Conference object

Open access