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- Effect of modified atmosphere on phytochemical profile of pasteurized peach puréesPublication . Oliveira, Ana; Coelho, Marta; Alexandre, Elisabete; Gomes, Maria Helena; Almeida, Domingos P. F.; Pintado, ManuelaPeach phytochemical profile was analysed during 90 days storage under three different gas mixtures: 10 kPa O2+90 kPa N2, 100 kPa N2 and air (78 kPa N2+21 kPa O2+0.03 kPa CO2) for both 4 and 23 °C. The antioxidant activity increased when peach purée was stored under air at 4 °C and 100 kPa N2 at 23 °C, while total phenolic content was not affected by atmospheres. Total carotenoids were more stable for 100 kPa N2, where it decreases 48 and 58% respectively for 4 and 23 °C. The content of (+)-catechin decreased 42% for 10 kPa O2 at 4°C, remaining constant in other atmospheres. Chlorogenic and neochlorogenic acids were well preserved in atmospheres containing oxygen, presenting an increase of 14 and 24% for 10 kPa O2 at 4°C. The higher content of carotenoids was obtained for 100 kPa N2 at 23 °C. Principal component analysis shows that atmospheres variance was associated with carotenoids while storage time was more related with total phenolics and total antioxidant capacity.
- Polyphenol extraction by different techniques for valorisation of non-compliant portuguese sweet cherries towards a novel antioxidant extractPublication . Vilas-Boas, Ana A.; Campos, Débora A.; Nunes, Catarina; Ribeiro, Sónia; Nunes, João; Oliveira, Ana; Pintado, ManuelaCurrently, there is special interest in the recovery of polyphenols from non-compliant fruits that have no market value; e orts to find value-added solutions for these food areas are a key option for a sustainable bio-economy. Saco cherries are a traditional Portuguese cherry variety, and although they are a nutritionally important food, rich in powerful dietary polyphenols, significant amounts of these cherries are not sold due to their small size. In this context, this work aimed to select the best method to produce novel antioxidant polyphenol-rich extracts from low calibre and non-compliant Saco cherries. Based on the results, microwaves-assisted extraction (MAE) allowed us to obtain a polyphenol-rich extract with a high antioxidant capacity (50.46 + 1.58 mg Trolox equivalent (TE)/g dry extract (DE) by oxygen radical absorbance capacity (ORAC), 10.88 + 0.38 mg ascorbic acid equivalent (AA)/g DE by 2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and 9.58 + 0.42 mg TE/g DE by 2,2-diphenyl-1-picrylhydrazyl (DPPH)) and a high content of polyphenols, namely, hydroxycinnamic acids (neochlorogenic and p-coumaric acids) and anthocyanins (cyanidin-3-rutinoside and cyanidin-3-glucoside), compared with those of conventional extractions with low and high temperature and ultrasound-assisted extraction. The antioxidant extract produced from MAE could be a new alternative for the valorisation of non-compliant cherries since these extracts proved to be a functional ingredient due to the high content of antioxidants, which are linked to the prevention of diseases.
- Simulated digestion of an olive pomace water-soluble ingredient: relationship between the bioaccessibility of compounds and their potential health benefitsPublication . Ribeiro, Tânia B.; Oliveira, Ana; Campos, Débora; Nunes, João; Vicente, António A.; Pintado, ManuelaOlive pomace is a semisolid by-product with great potential as a source of bioactive compounds. Using its soluble fraction, a liquid-enriched powder (LOPP) was obtained, exhibiting a rich composition in sugars, polyphenols and minerals, with potential antioxidant, antihypertensive and antidiabetic health benefits. To validate the potential of LOPP as a functional ingredient the effect of the gastrointestinal tract on its bioactive composition and bioactivities was examined. Polyphenols and minerals were the most affected compounds; however, a significant bioaccessibility of potassium and hydroxytyrosol was verified (≥57%). As a consequence, the LOPP bioactivities were only moderately affected (losses around 50%). For example, 57.82 ± 1.27% of the recovered antioxidant activity by ORAC was serum-available. From an initial α-glucosidase inhibition activity of 87.11 ± 1.04%, at least 50% of the initial potential was retained (43.82 ± 1.14%). Regarding the initial ACE inhibitory activity (91.98 ± 3.24%), after gastrointestinal tract losses, significant antihypertensive activity was retained in the serum-available fraction (43.4 ± 3.65%). The colon-available fraction also exhibited an abundant composition in phenolics and minerals. LOPP showed to be a potential functional ingredient not only with potential benefits in preventing cardiovascular diseases but also in gut health.
- Impact of extraction process in non-compliant ‘Bravo de Esmolfe’ apples towards the development of natural antioxidant extractsPublication . Vilas-Boas, Ana A.; Oliveira, Ana; Ribeiro, Tânia B.; Ribeiro, Sónia; Nunes, Catarina; Gómez-García, Ricardo; Nunes, João; Pintado, ManuelaThe ‘Bravo de Esmolfe’ apple (BE) is rich in antioxidants and represents one of the most important traditional cultivars in Portugal. A large amount of non-compliant BE, with no market value, it is generated every year. Thus, an effort to find value-added solutions is of utmost importance. For the first time, green extraction (microwave-assisted-extraction (MAE) and ultrasound-assisted-extraction (UAE)) were compared against conventional extraction (with (CET) and without temperature (CE)) to select the most efficient process to produce a natural antioxidant extract from non-compliant BE. The results showed that MAE and CET are good methodologies for developing a BE antioxidant extract. However, MAE is more sustainable than CET, requiring less time to reach high temperatures. The MAE-extract showed great antioxidant activity (14.80 ± 0.70 mg TE/g DE by ORAC, 3.92 ± 0.25 mg AAE/g DE by ABTS, and 5.11 ± 0.13 mg TE/g DE by DPPH). This extract revealed high amount of chlorogenic acid (0.48 ± 0.07 mg/g DE), (-)-epicatechin (0.30 ± 0.02 mg/g DE) and phloridzin (0.13 ± 0.01 mg/g DE). This study shows that non-compliant BE is a useful source of antioxidants, being a sustainable way for the recovery of value-added compounds from the rejected fruit in line with sustainable and circular bioeconomy principles.
- Simulated digestion of olive pomace water-soluble ingredient : relationship between the compounds bioaccessibility and their potential health benefitsPublication . Ribeiro, Tânia; Oliveira, Ana; Campos, Débora; Nunes, João; Vicente, António A.; Pintado, ManuelaOlive pomace is a semisolid by-product with a great potential as a source of bioactive compounds. Using its soluble fraction, a liquid-enriched powder (LOPP) was obtained, exhibiting a rich composition in sugars, polyphenols and minerals, with potential antioxidant, antihypertensive and antidiabetic health benefits. To validate LOPP potential as a functional ingredient the effect of the gastrointestinal tract on its bioactive composition and bioactivities was examined. Polyphenols and minerals were the most affected compounds, however, a significant bioaccessibility of potassium and hydroxytyrosol was verified (> 57 %). As a consequence, the LOPP bioactivities were only moderately affected (losses around 50%). For example, 57.82 ± 1.27 % of the recovered antioxidant activity by ORAC was serum - available. From an initial a-glucosidase inhibition activity of 87.11 ± 1.04 %, at least 50% of the initial potential was kept (43.82 ± 1.14 %). Regarding initial ACE inhibitory activity (91.98 ± 3.24 %), after gastrointestinal tract losses, significant antihypertensive activity was retained in the serum-available fraction (43.4 ± 3.65 %). The colon-available fraction also exhibited an abundant composition in phenolics and minerals. LOPP showed to be a potential functional ingredient not only with potential benefits in preventing cardiovascular diseases but also in gut health.