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- Impact of processing approach and storage time on bioactive and biological properties of rocket, spinach and watercress byproductsPublication . Araújo-Rodrigues, Helena; Santos, Diva; Campos, Débora A.; Guerreiro, Suse; Ratinho, Modesta; Rodrigues, Ivo M.; Pintado, Manuela E.The high nutritional value of vegetables is well recognized, but their short shelf life and seasonal nature result in massive losses and wastes. Vegetable’s byproducts are an opportunity to develop value-added ingredients, increasing food system efficiency and environmental sustainability. In the present work, pulps and powders of byproducts from rocket and spinach leaves and watercress were developed and stored for six months under freezing and vacuum conditions, respectively. After processing and storage, microbiological quality, bioactive compounds (polyphenols, carotenoids and tocopherols profiles), antioxidant capacity, and pulps viscosity were analyzed. Generally, the developed vegetable’s pulps and powders were considered microbiologically safe. Although some variations after processing and storage were verified, the antioxidant activity was preserved or improved. A rich phenolic composition was also registered and maintained. During freezing, the quantitative carotenoid profile was significantly improved (mainly in rocket and spinach), while after drying, there was a significant decrease. A positive effect was verified in the vitamin E level. Both processing and storage conditions resulted in products with relevant phenolics, carotenoids and tocopherol levels, contributing to the antioxidant activity registered. Thus, this study demonstrates the potential of vegetable byproducts valorization through developing these functional ingredients bringing economic and environmental value into the food chain.
- Development of frozen pulps and powders from carrot and tomato by-products: impact of processing and storage time on bioactive and biological propertiesPublication . Araújo-Rodrigues, Helena; Santos, Diva; Campos, Débora A.; Ratinho, Modesta; Rodrigues, Ivo M.; Pintado, Manuela E.Vegetables and fruits have an interesting nutritional profile, rich in bioactive metabolites, holding a high antioxidant potential and health associated benefits. However, their functional properties, the shorter shelf-life due to their high-water content, and their seasonality nature lead to extensive food losses and waste. The valorization of vegetables and fruits by-products through the development of value-added products and the application of preservation methods is of utmost importance to prevent food losses and waste. In this study, based on a circular economy approach, pulps and powders of baby carrot and cherry tomato by-products were prepared. Freezing, hot air drying and storage time impact on antioxidant activity and bioactive compounds were studied. Microbiological quality and pulps viscosity were also monitored for 6 months. During the freezing storage, TPC and antioxidant capacity by ABTS and ORAC assays decreased. The antioxidant capacity by DPPH method and carotenoid content increased during the first months of freezing, but then decreased. The drying process negatively affected the antioxidant capacity as well as carotenoid and polyphenolic content compared with the fresh vegetables. Both processing methodologies positively impacted the vitamin E content. During drying storage, there were no key variations in antioxidant capacity and bioactive content.
- Characterization of the aroma and colour profiles of fortified Muscat wines: comparison of Muscat Blanc “à petit grains” grape variety with Red MuscatPublication . Jesus, Diva; Campos, Francisco M.; Ferreira, Miguel; Couto, José A.Although Muscat Blanc “à petit grains” and Red Muscat grape varieties are both cultivated in the Douro Demarcated Region (Portugal), only Muscat Blanc is currently authorized for the production of the fortified wine “Moscatel do Douro”. The aim of this study was to evaluate the potential of the Red Muscat grape variety to be employed in the winemaking of Douro Muscat wines. Wines of both grape varieties were produced from the 2013 and 2014 harvests, and were chemically and sensory analysed 12 and 3 months after stopping the alcoholic fermentation, respectively. The Muscat Blanc “à petit grains” variety produced musts with higher sugar content than the red variety, but the final levels of sugar and ethanol were similar in all wines owing to the control of the fermentation time. Red Muscat wines presented higher concentrations of rose oxide and nerol than Muscat Blanc “à petit grains”; however, these differences were only significant in the youngest wines. Linalool and α-terpineol were found at higher levels in the 2013 Muscat Blanc “à petit grains” wines. No significant differences were found for the ester compounds, except for 2-phenylethanol, which was higher in the Red Muscat wines. The 12 months old wines presented a higher total concentration of esters than the younger wines. No significant differences were found for the higher alcohols composition between the two grape varieties. The chromatic analysis showed that, besides having a redder tone, Red Muscat wines had a higher colour intensity and a more pure/saturated colour than Muscat Blanc “à petit grains” wines. The sensory analysis did not detect significant differences in the aromatic and gustatory profiles between the two grape varieties. The Red Muscat grape variety shows great potential to be employed in the production of Muscat fortified wine either as monovarietal or in blends with Muscat Blanc “à petit grains”.
- Chlorogenic acids composition and the impact of in vitro gastrointestinal digestion on espresso coffee from single-dose capsulePublication . Vilas-Boas, Armando; Oliveira, Ana; Jesus, Diva; Rodrigues, Carla; Figueira, Cláudia; Gomes, Ana; Pintado, ManuelaThe single-dose coffee capsule is the most successful technology used to prepare espresso coffee (EC). However, the characterization of ECs extracted using this technology, regarding chlorogenic acids (CGAs) composition, antioxidant activity and stability during gastrointestinal digestion (GID), are still limited. The aim of this research work was: (i) to characterize the phenolic profile and antioxidant activity of 11 commercial ECs from single-dose capsule system and (ii) to evaluate the impact of the in vitro GID on the stability of CGAs. Within all the ECs analysed it was detected the presence of 4 caffeoylquinic acids (CQAs), 1 feruloylquinic acids, 2 caffeoylshikimic acids and 3 diCaffeoylquinic acids (di-CQAs). The major compound in all ECs was 5-CQA, followed by 4-CQA and 3-CQA. The di-CQAs were found in lower concentration than CQAs (4,5-diCQA > 3,4-diCQA > 3,5-diCQA). The total CQAs and diCQAs content of the ECs analyzed ranged from 1.86 ± 0.19 to 2.42 ± 0.28 and 0.26 ± 0.02 to 0.42 ± 0.06 mg/mL of EC, respectively. The high antioxidant activity of the ECs is related with the high CGAs concentration, which ranged from 4.92 ± 0.29 to 7.28 ± 0.25 mg AAE/mL of EC and from 6.13 ± 0.37 to 10.07 ± 0.17 mg TE/mL of EC for ABTS° and DPPH° methods, respectively. The principal component analysis showed that the coffee variety used in ECs preparation explained 74.8% of the results’ variation and that 6 of the total number of ECs were related with high CGAs contents and antioxidant activity. The GID induced a decrease in most CGAs, which had a direct impact on the antioxidant activity, therefore concerning EC ingestion the CGAs bioaccessible concentration decreased in comparison with a non-digested EC. Nevertheless, the CGAs concentration available after GID is still sufficiently high to exert antioxidant activity (measured in vitro) that may exert a potential beneficial effect on humans health.