scholarly journals Study of polyphenols, antioxidant capacity and minerals for the valorisation of ancient apple cultivars from Northeast Italy

Author(s):  
Raffaella Preti ◽  
Anna Maria Tarola

Abstract Nutritional properties and quality of apple fruits can be related to presence of secondary metabolite contents such as phytochemicals and mineral elements. In this paper, eight polyphenols, four major minerals (Na, K, Mg, Ca), total phenolic content and antioxidant capacity were determined in fourteen ancient apple cultivars grown in Friuli Venezia Giulia (Northeast Italy) to highlight their nutraceutical properties. Both apple peel and pulp were examined separately and results were compared to those of six widespread commercial cultivars using principal component analysis. Ancient apples had much higher content in healthful compounds with respect to commercial varieties, particularly in the peel. Ancient cultivars showed a superior antioxidant capacity in peel (3- to 9- fold) and in pulp (2- to 5-fold) compared to commercial cultivars, with a good correlation with total phenolic content (R = 0.83 in peel and 0.69 in pulp). The polyphenols that mostly characterized the ancient apples pulp were catechins and flavonols. Regarding macro elements, K and Mg content were higher in ancient cultivars, while Na and Ca showed no significant differences. In the perspective of a sustainable economic and social development of local agricultural realities, these results contribute to the valorisation of ancient local apple cultivars as invaluable reservoir of genetic biodiversity to be promoted as functional food or exploited in breeding novel apple hybrids with high nutraceutical properties and better resistance to parasites.

2013 ◽  
Vol 16 (4) ◽  
pp. 301-309 ◽  
Author(s):  
Clináscia Rodrigues Rocha Araújo ◽  
Thiago de Mello Silva ◽  
Monica Lopes ◽  
Paula Villela ◽  
Antônio Flávio de Carvalho Alcântara ◽  
...  

The in vitro antioxidant capacity, total phenolic content and mineral elements of the fruit peel of Myrciaria cauliflora were investigated. The antioxidant capacity was analyzed by the diphenylpicrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP) and β-carotene methods. The assays based on the DPPH (EC50 = 3.18 g sample/g DPPH), ABTS•+ (1017 μmol Trolox/g sample), FRAP (1676 µM Fe2SO4/g sample) and β-carotene/linoleic acid (70% of oxidation inhibition) methods indicated a high antioxidant capacity of the fruit peel extract of the plant. The Folin-Denis method was more efficient in determining the total phenolic compound contents in the different solvents than the Folin-Ciocalteu one. Extractions made with 4:1 methanol-water, 4:1 ethanol-water, 3:2 ethanol-water and 3:2 acetone-water solutions using the Folin-Denis method exhibited high contents of phenolic compounds (18.95, 14.06, 12.93 and 11.99 mg GAE/g, respectively). Potassium was the major element found in the fruit peel, followed by phosphorus, calcium, magnesium and iron, in that order. As a result, the fruit peel of M. cauliflora can be considered as an important source of natural antioxidants and essential elements of easy access for the population and for application in the food industry.


2013 ◽  
Vol 19 (3-4) ◽  
Author(s):  
N. Papp ◽  
T. Szabó ◽  
Z. Szabó ◽  
J. Nyéki ◽  
A. Hegedűs

Fruits of twelve quince (Cydonia oblonga Mill.) commercial cultivars and selections were compared in the ferric reducing antioxidant power (FRAP) and total phenolic content (TPC) of intact and peeled fruits. The antioxidant capacity and total phenolic content ranged between 5.99 and 63.10 mmol AA/100 g FW, and 3.92 and 12.83 g GA/100 g FW, respectively. These ranges cover an almost 8-times variation among the tested genotypes in case of antioxidant capacity and also declares two-times variation for total polyphenolic content. Cultivars ‘Aromate’ and ‘Bereczki’ possessed the lowest antioxidant capacity and ‘Román portugál’ and ‘Bereczki’ had the lowest polyphenolic contents. In contrast, cultivars ‘Champion’ and ‘Konstantinápolyi’ possessed the highest antioxidant capacity and ‘Mezôtúri’ and ‘De Husi’ had the highest polyphenolic contents. The Pearson’s coeffi cient was relatively moderate but signifi cant (r=0.51) indicating a weak interdependence between FRAP and TPC values of quince fruits. Our results led us to the conclusion that quince might be considered as a valuable source of antioxidants and polyphenolics.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Raffaella Preti ◽  
Anna Maria Tarola

PurposeUrban beekeeping is spreading as an answer to promote bee conservation and to develop local economies. This study aims to highlight nutritional properties of polyfloral honeys produced in urban landscape and to compare them to the countryside counterparts.Design/methodology/approachThis research has examined polyfloral urban honeys from a restricted area in Central Italy, for antioxidant capacity, total phenolic content and 15 polyphenols profile. Physicochemical parameters have been also determined to assess the overall quality of the samples. Results were compared with polyfloral honeys produced in surrounding countryside and monitored in two harvest years, 2018 and 2019. Principal component analysis was applied to the data to disclose significant differences among honeys and harvest years.FindingsUrban honeys revealed up to threefold higher total amount of polyphenols with respect to rural honeys, and in the 2019 harvest, despite water scarcity that affected the national production, demonstrated 50% higher antioxidant capacity and total phenolic content. The majority of the 15 polyphenols studied resulted in more abundant urban honeys, in particular in the 2019 harvest. The multivariate analysis evidenced how honeys could be successfully separated according to their production area and harvest year by their different polyphenols profile.Originality/valueLimited data are available on nutritional properties of urban honeys and on their content in antioxidants. The present results suggest that the cultivated urban environment, with its large floral biodiversity, can provide extra nutrition for bees, resulting in the production of a honey rich in nutraceutical compounds.


2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1255
Author(s):  
Sofia C. Lourenço ◽  
Débora A. Campos ◽  
Ricardo Gómez-García ◽  
Manuela Pintado ◽  
M. Conceição Oliveira ◽  
...  

Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80–20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.


Foods ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 281 ◽  
Author(s):  
Saleha Akter ◽  
Michael E. Netzel ◽  
Ujang Tinggi ◽  
Simone A. Osborne ◽  
Mary T. Fletcher ◽  
...  

Terminalia ferdinandiana (Kakadu plum) is a native Australian plant containing phytochemicals with antioxidant capacity. In the search for alternatives to synthetic preservatives, antioxidants from plants and herbs are increasingly being investigated for the preservation of food. In this study, extracts were prepared from Terminalia ferdinandiana fruit, leaves, seedcoats, and bark using different solvents. Hydrolysable and condensed tannin contents in the extracts were determined, as well as antioxidant capacity, by measuring the total phenolic content (TPC) and free radical scavenging activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. Total phenolic content was higher in the fruits and barks with methanol extracts, containing the highest TPC, hydrolysable tannins, and DPPH-free radical scavenging capacity (12.2 ± 2.8 g/100 g dry weight (DW), 55 ± 2 mg/100 g DW, and 93% respectively). Saponins and condensed tannins were highest in bark extracts (7.0 ± 0.2 and 6.5 ± 0.7 g/100 g DW). The antimicrobial activity of extracts from fruit and leaves showed larger zones of inhibition, compared to seedcoats and barks, against the foodborne bacteria Listeria monocytogenes, Bacillus cereus, Methicillin resistant Staphylococcus aureus, and clinical isolates of Pseudomonas aeruginosa. The minimum inhibitory concentration and minimum bactericidal concentration in response to the different extracts ranged from 1.0 to 3.0 mg/mL. Scanning electron microscopy images of the treated bacteria showed morphological changes, leading to cell death. These results suggest that antioxidant rich extracts of Terminalia ferdinandiana fruits and leaves have potential applications as natural antimicrobials in food preservation.


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