Vegetable peels as natural antioxidants for processed foods – A review

2016 ◽  
Vol 37 (1) ◽  
Author(s):  
N. S. Sonia ◽  
C. Mini ◽  
P. R. Geethalekshmi

Antioxidants are substances that are able to prevent or inhibit oxidation processes in human body as well as in food products. Oxidation reactions can produce free radicals, which start chain reactions that damage cells. Antioxidants terminate these chain reactions by removing free radical intermediates and inhibit other oxidation reactions by being oxidized it selves. The protection of foods from oxygen is the basic principle upon which antioxidant protective technologies are based. Both synthetic as well as natural antioxidants are using in food industry but the application of synthetics has been reassessed due to its potential carcinogenic effects. Research is being focused on vegetable materials which are a rich source of antioxidant compounds. Various antioxidant compounds have been isolated, many of them being polyphenols. Direct relationship exists between the total phenolic contents and the antioxidant activity in fruits and vegetables. The entire tissue of fruits and vegetables are rich in bio-active compounds and in most cases the waste by-products can present similar or even higher contents of antioxidant compounds. The waste materials such as peels, seeds and stones produced from the fruit and vegetable processing unit can be successfully used as a source of phytochemicals and antioxidants. Different antioxidant sources, their mode of action, application in food industry and antioxidant activities of banana peel, watermelon peel, potato peel and cucumber peel are reviewed in this paper.

2019 ◽  
Vol 17 (1) ◽  
pp. 841-848
Author(s):  
Xiao-Fang Hu ◽  
Zong-Bao Ding ◽  
Yue Chen ◽  
Jiang-Fu Luo ◽  
Jian-Min He ◽  
...  

AbstractFlower teas are widely consumed across the world because of their beneficial health effects. The antioxidant activities of methanol extracts from ten common flower teas in China were evaluated using four antioxidant assays. The total phenolic (TPCs) and total flavonoid contents (TFCs) were also investigated. Most of these flower teas exhibited potent antioxidant effects, of which rosae rugosae flos exerted the strongest antioxidant effects in four assays. Rosae rugosae flos also exerted the highest TPC, while fragrans showed the highest TFC. Correction analysis indicated that phenolics play a key role in the antioxidant effect of flower teas, while flavonoids were poorly correlated with antioxidant activity. The results supported the consumption of flower teas as functional foods and their application as sources of natural antioxidants in the food industry.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4399
Author(s):  
Norhasnida Zawawi ◽  
Pei Juin Chong ◽  
Nurul Nadhirah Mohd Tom ◽  
Nurkhairina Solehah Saiful Anuar ◽  
Salma Malihah Mohammad ◽  
...  

Honey is a well-known natural sweetener and is rich in natural antioxidants that prevent the occurrence of oxidative stress, which is responsible for many human diseases. Some of the biochemical compounds in honey that contribute to this property are vitamins and phenolic compounds such as phenolic acids and flavonoids. However, the extent to which these molecules contribute towards the antioxidant capacity in vitro is inconsistently reported, especially with the different analytical methods used, as well as other extrinsic factors that influence these molecules’ availability. Therefore, by reviewing recently published works correlating the vitamin, total phenolic, and flavonoid content in honey with its antioxidant activities in vitro, this paper will establish a relationship between these parameters. Based on the literature, vitamins do not contribute to honey’s antioxidant capacity; however, the content of phenolic acids and flavonoids has an impact on honey’s antioxidant activity.


2013 ◽  
Vol 41 (1) ◽  
pp. 136 ◽  
Author(s):  
Violeta NOUR ◽  
Ion TRANDAFIR ◽  
Mira E. IONICA

Ten indeterminate tomato cultivars differing in fruit shape and typology, grown simultaneously in a greenhouse from Oltenia (Southwestern Romania) and harvested at red ripe stage, were investigated for the contents in ascorbic acid, lycopene, β-carotene, total phenolics, minerals (K, Na, Ca and Mg) and trace elements (Fe, Cu, Mn, Cr, Zn and B). In addition, their antioxidant activities were determined. Significant differences were found among tomato cultivars in all studied antioxidant compounds, as well as in the antioxidant activity. Ascorbic acid ranged from 91.9 to 329.7 mg kg-1 fw, lycopene ranged from 19.7 to 49.0 mg kg-1 fw, while total phenolic compounds varied between 300.2 and 557.8 mg kg-1 fw. Antioxidant activity ranged from 0.81 mmol Trolox kg-1 fw to 1.74 mmol Trolox kg-1 fw and it was significantly correlated to total phenolics content (r = 0.91; p< 0.05). The cocktail type cultivar ‘Tiger’ and the cherry type cultivar ‘Belle’ proved to be the most powerful in antioxidant activity and phenolic compounds while the rectangular plum shaped cultivar ‘Porto’ recorded the highest average lycopene content. A valuable cultivar proved to be the brownish red ‘Sacher’ which registered among the highest contents of phenolics, lycopene and ascorbic acid. Mineral and trace elements contents were also significantly affected by cultivars. Values recorded for K, Ca and Mg ranged from 2139.6 to 3056.9 mg kg-1, 137.7 to 325.8 mg kg-1 and 27.3 to 168.7 mg kg-1 respectively.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Lizbeth A. Castro-Concha ◽  
Jemina Tuyub-Che ◽  
Angel Moo-Mukul ◽  
Felipe A. Vazquez-Flota ◽  
Maria L. Miranda-Ham

In the past few years, there has been a renewed interest in studying a wide variety of food products that show beneficial effects on human health.Capsicumis an important agricultural crop, not only because its economic importance, but also for the nutritional values of its pods, mainly due to the fact that they are an excellent source of antioxidant compounds, and also of specific constituents such as the pungent capsaicinoids localized in the placental tissue. This current study was designed to evaluate the antioxidant capacity and total phenolic contents from fruits tissues of twoCapsicum chinenseaccessions, namely, Chak k’an-iik (orange) and MR8H (red), at contrasting maturation stages. Results showed that red immature placental tissue, with a Trolox equivalent antioxidant capacity (TEAC) value of 55.59 μmols TE g−1 FW, exhibited the strongest total antioxidant capacity using both the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the CUPRAC methods. Placental tissue also had the highest total phenolic content (27 g GAE 100 g−1 FW). The antioxidant capacity ofCapsicumwas directly related to the total amount of phenolic compounds detected. In particular, placentas had high levels of capsaicinoids, which might be the principal responsible for their strong antioxidant activities.


Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 174
Author(s):  
Hefei Zhao ◽  
Roberto J. Avena-Bustillos ◽  
Selina C. Wang

Olive pomace (OP) is a valuable food byproduct that contains natural phenolic compounds with health benefits related to their antioxidant activities. Few investigations have been conducted on OP from the United States while many studies on European OP have been reported. OP of Arbequina, the most common cultivar from California, was collected and extracted by water, 70% methanol and 70% ethanol, followed by purification using macroporous absorbing resin. Results showed that the extractable total phenolic content (TPC) was 36–43 mg gallic acid equivalents (GAE)/g in pitted, drum-dried defatted olive pomace (DOP), with major contributions from hydroxytyrosol, oleuropein, rutin, verbascoside, 4-hydroxyphenyl acetic acid, hydroxytyrosol-glucoside and tyrosol-glucoside. Macroporous resin purification increased TPC by 4.6 times the ethanol crude extracts of DOP, while removing 37.33% total sugar. The antioxidant activities increased 3.7 times Trolox equivalents (TrE) by DPPH and 4.7 times TrE by ferric reducing antioxidant power (FRAP) in the resin purified extracts compared to the ethanol crude extracts. This study provided a new understanding of the extraction of the bioactive compounds from OP which could lead to practical applications as natural antioxidants, preservatives and antimicrobials in clean-label foods in the US.


2020 ◽  
Vol 23 ◽  
Author(s):  
Karina Carvalho Guimarães ◽  
Derlyene Lucas Salgado ◽  
Elisângela Elena Nunes Carvalho

Abstract Phenolic compounds are natural antioxidants and can be found with abundance in fruits and vegetables. One of the first methods created for analyzing phenolic compounds was the Folin-Denis method; and hereafter, the Folin Ciocalteu method was developed and recently, one of the most recent method is the Fast Blue. Due to the importance of these compounds in food, this work aimed to determine the total phenolic compounds in three fruits, such as: Passion Fruit, “Palmer” mango and “Pera” orange. In addition, these fruits were analyzed through three different determination methods. Furthermore, the content of vitamin C, soluble solids, titratable acidity and pH of these fruits were evaluated. Based on the results, it was verified that there was no difference among the values of vitamin C, soluble solids and TA in relation to those found in the literature. When comparing the three methods (Fast Blue BB, Folin-Ciocalteu Reagent and Folin-Denis Reagent), the results showed a difference in the phenolic compounds that may be related to the distinct reagents used in each method and its different action.


Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4132 ◽  
Author(s):  
Sofia C. Lourenço ◽  
Margarida Moldão-Martins ◽  
Vítor D. Alves

In recent years, great interest has been focused on using natural antioxidants in food products, due to studies indicating possible adverse effects that may be related to the consumption of synthetic antioxidants. A variety of plant materials are known to be natural sources of antioxidants, such as herbs, spices, seeds, fruits and vegetables. The interest in these natural components is not only due to their biological value, but also to their economic impact, as most of them may be extracted from food by-products and under-exploited plant species. This article provides an overview of current knowledge on natural antioxidants: their sources, extraction methods and stabilization processes. In addition, recent studies on their applications in the food industry are also addressed; namely, as preservatives in different food products and in active films for packaging purposes and edible coatings.


Author(s):  
RASNA GUPTA ◽  
RAM LAKHAN SINGH ◽  
ANKIT GUPTA

Objective: The present study was undertaken to investigate the antioxidative activity of fruit pulp, seed and bark of T. bellerica. Methods: Methanol (70%) and water were used for the extraction, and the respective extracts were analyzed for total phenolic contents along with the antioxidant activities through different assays. Results: Amongst the tested extracts, methanolic extracts were found to be better than aqueous with the highest total phenolic contents (TPC). Methanolic fruit pulp showed lower IC50 for free radical (118.7 µg/ml), superoxide anion radical (77.65 µg/ml) and hydroxyl radical (73.76 µg/ml) scavenging activities. Methanolic fruit pulp also showed lower IC50 for lipid peroxidation (115.6 µg/ml) and ferric thiocyanate (184.98 µg/ml) assay than aqueous extracts in comparison to standard quercetin. Further, correlation between TPC and antioxidant studies revealed that phenolics are mainly responsible for antioxidant activity of T. bellerica. Conclusion: The current study suggests that the methanolic extract of T. bellerica could be a potential source of natural antioxidants for food and pharmaceutical companies.


Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 295 ◽  
Author(s):  
Hyo In Yoon ◽  
Wenjuan Zhang ◽  
Jung Eek Son

Among abiotic stresses, both drought and UV-B radiation effectively trigger the accumulation of secondary metabolites, and can be widely applied in plant factories. The objectives of this study were to investigate antioxidant accumulation under drought stress alone, or in combination with UV-B radiation near harvest, and to determine an optimal treatment time for maximum antioxidant production. Kale (Brassica oleracea L. var. acephala) plants were grown in a plant factory and harvested at 42 days after transplanting. The single and combination treatments lasted for 7 to 1 days and 4 to 2 days before harvest, respectively. The results of both Fv/Fm (maximal photochemical efficiency in photosystem II) and leaf water potential could ensure the function of photosynthesis and maintain normal leaf moisture in single drought treatments of less than 4 days. The total phenolic and flavonoid contents and antioxidant activities were significantly increased in both single and combination treatments for 3 to 4 days, compared to other treatments. The supplementary UV-B treatments showed no extra formation of antioxidants compared to the single drought treatments. As a result, drought for 3 days before harvest could achieve the highest potential value of kale as a source of natural antioxidants.


Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 405 ◽  
Author(s):  
Chunhe Gu ◽  
Kate Howell ◽  
Frank R. Dunshea ◽  
Hafiz A. R. Suleria

Polyphenols are naturally occurring compounds found largely in fruits and vegetables. The antioxidant properties of these polyphenols including total phenolic content (TPC), total flavonoid content (TFC), tannin content, 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH), 2,2′-azinobis-(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS) scavenging abilities and ferric ion reducing antioxidant power (FRAP) were measured among sixteen (16) plant foods (mango, blueberry, strawberry, black carrot, raspberry, dark grapes, garlic, ginger, onion, cherry, plum, apple, papaya, peach, pear and apricot) by modifying, standardising and translating existing antioxidant methods using a 96-well plate reader. Eighteen targeted phenolic acids and flavonoids were characterised and quantified using high-performance liquid chromatography-photometric diode array (HPLC-PDA) and verified by modifying an existing method of liquid chromatography coupled with electrospray-ionisation triple quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS). While most of these compounds were accurately detected by the HPLC-PDA at a low concentration, a few polyphenols in low concentrations could be only be characterised using the LC-ESI-QTOF/MS method. Our results showed that mango possessed the highest overall antioxidant activity, phenolic acid and flavonoid content among the selected fruits. Factor analysis (FA) and Pearson’s correlation tests showed high correlations among ABTS, DPPH, FRAP and phenolic acids, implying the comparable capabilities of scavenging the DPPH/ABTS free radicals and reducing ferric ions from the antioxidant compounds in the samples. Phenolic acids contributed significantly to the antioxidant activities, and flavonoids contributed more to tannin content based on the correlations. Overall, methods modified and standardized in this study can provide better understanding of high throughput technologies and increase the reliability of antioxidant data of different plant foods.


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