Antioxidant compounds, antioxidant activity and phenolic content in peel from three tropical fruits from Yucatan, Mexico

An Overview of Plant Phenolic Compounds and Their Importance in Human Nutrition and Management of Type 2 Diabetes

In this paper, the biosynthesis process of phenolic compounds in plants is summarized, which include the shikimate, pentose phosphate and phenylpropanoid pathways. Plant phenolic compounds can act as antioxidants, structural polymers (lignin), attractants (flavonoids and carotenoids), UV screens (flavonoids), signal compounds (salicylic acid, flavonoids) and defense response chemicals (tannins, phytoalexins). From a human physiological standpoint, phenolic compounds are vital in defense responses, such as anti-aging, anti-inflammatory, antioxidant and anti-proliferative activities. Therefore, it is beneficial to eat such plant foods that have a high antioxidant compound content, which will cut down the incidence of certain chronic diseases, for instance diabetes, cancers and cardiovascular diseases, through the management of oxidative stress. Furthermore, berries and other fruits with low-amylase and high-glucosidase inhibitory activities could be thought of as candidate food items in the control of the early stages of hyperglycemia associated with type 2 diabetes.

A New Age for Quercus spp. Fruits: Review on Nutritional and Phytochemical Composition and Related Biological Activities of Acorns

The current global food system must adapt to the expected growth of world population (about 9 billion individuals by 2050). This adaptation will probably include an increased consumption of edible wild foods, due to their richness in micronutrients and bioactive compounds, besides providing a cost-effective and sustainable way of improving caloric food security. A striking example of such natural matrices is the Quercus genus, which has the additional advantage of being widespread throughout the Northern Hemisphere. In a traditional sense, Quercus fruits (acorns) were mainly used in animal feeding, despite their potentially important role on the rural economy. But this preconception is changing. In fact, their nutritional value, high contents in phytochemical compounds, biological activity (such as antioxidant, anticarcinogenic, and cardioprotective properties) and use in the treatment of specific diseases (such as atherosclerosis, diabetes, or Alzheimer's disease) have raised the interest in integrating acorns into the human diet. Accordingly, this comprehensive overview was designed to provide an evidence-based review of the literature, with the objective to achieve useful conclusions regarding the nutritional properties, methodologies of extraction, identification, and characterization of a wide variety of bioactive compounds and scientifically validated bioactivities in Quercus species worldwide. The industrial by-products from acorn oil extraction or flour production are also included. Data regarding the analytical techniques, individual compounds, and their bioactivities, are organized in tables. The reported data are discussed and directions for further investigations are suggested, highlighting the use of acorns in food, nutraceutical, and pharmaceutical applications.

Influence of Yellow Light-Emitting Diodes at 590 nm on Storage of Apple, Tomato and Bell Pepper Fruit

The objective of this study is to investigate the effects of irradiation from light-emitting diodes (LEDs) on several fruits during storage. To improve storage and increase the contents of some bioactive compounds, apple, tomato and red bell pepper fruits were exposed to yellow light emitted from the diodes at 590 nm. The contents of ascorbic acid, total phenolics, total flavonoids and several pigments were investigated, along with the antioxidant potential. The colour parameters (L*, a* and b*) and firmness of the fruit were also determined. After 7 days of LED light irradiation, there was significantly higher total phenolic content and antioxidant potential in apple peel extracts. The irradiated fruit of tomato had significantly higher levels of total phenolic compounds, and the fruit of red bell pepper had significantly higher antioxidant potential. LED light had no effects on the colour parameters, although there was a tendency to accelerate colour development. Apple fruit irradiated with LED light was significantly less firm. Among twelve analysed pigments, significantly more β-carotene was detected in LED light-irradiated apple and bell pepper fruit, more α-tocopherol and γ-tocopherol in bell pepper fruit, and more lutein in apple peel and bell pepper fruit. The applied LED light slightly accelerated the ripening of the studied fruit, and affected the synthesis of some of the secondary metabolites.

The antioxidant activity and their major antioxidant compounds from Acanthopanax senticosus and A. koreanum

The antioxidant activity and chlorogenic acid and caffeic acid contents were investigated from different parts of Acanthopanax senticosus and A. koreanum. Antioxidant activity was assessed by various in vitro assays such as DPPH, ABTS, FRAP, reducing power assays and ORAC, and the chlorogenic acid and caffeic acid were validated by HPLC chromatography. Among the various extracts, the fruit extracts of A. senticosus and A. koreanum exhibited strongest antioxidant activities including ABTS, FRAP, reducing power and ORAC, however, strongest DPPH radical scavenging activity was observed from the leaf extract of A. senticosus. In addition, the antioxidant activities of various extracts were correlated with total phenolic and proanthocyanidin contents. The major phenolic contents from various parts of these plants observed that leaf extract of A. senticosus expressed higher levels of chlorogenic acid (14.86 mg/dry weigh g) and caffeic acid (3.09 mg/dry weigh g) than other parts. Therefore, these results suggest that the leaf of A. senticosus may be an excellent natural source for functional foods and pharmaceutical agents, and the validated method was useful for the quality control of A. senticosus.

Evaluation of toxic, cytotoxic, mutagenic, and antimutagenic activities of natural and technical cashew nut shell liquids using the Allium cepa and Artemia salina bioassays

The cashew nut releases a substance that is known as cashew nut shell liquid (CNSL). There are both natural (iCNSL) and technical (tCNSL) cashew nut shell liquids. This study used an Artemia salina bioassay to evaluate the toxic effects of iCNSL and tCNSL cashew nut shell liquids. It also evaluated the toxicity, cytotoxicity, and mutagenicity of CNSL and its effects on the damage induced by copper sulfate (CuSO4·5H2O) on the meristems' root of Allium cepa. Effects of the damage induced by CuSO4·5H2O were evaluated before (pre-), during (co-), and after (post-) treatments. The iCNSL contained 94.5% anacardic acid, and the tCNSL contained 91.3% cardanol. The liquids were toxic to A. salina. Toxicity, cytotoxicity, and mutagenicity were observed with iCNSL compared with the negative control. Similarly, iCNSL failed to inhibit the toxicity and cytotoxicity of CuSO4·5H2O. The tCNSL was not toxic, cytotoxic, or mutagenic in any of the concentrations. However, the lowest iCNSL concentrations and all of the tCNSL concentrations had preventive, antimutagenic, and reparative effects on micronuclei and on chromosomal aberrations in the A. cepa. Therefore, protective, modulating, and reparative effects may be observed in the A. cepa, depending on the concentration and type of CNSL used.

Antioxidant properties can be tuned in the presence of an external electric field: accurate computation of O–H BDE with range-separated density functionals

The effect of external electric field on the antioxidant properties of gallic and caffeic acids is studied. The performance of range-separated functionals in reproducing the O–H BDE is tested in the presence of an external electric field.

Phenolic compounds in edible species of the Anacardiaceae family – a review

Members of the Anacardiaceae (cashew family) are of economic importance and contain a diverse range of phenolic compounds.