Phenolic compounds constitute a group of secondary metabolites which have important functions in plants. Besides the beneficial effects on the plant host, phenolic metabolites (polyphenols) exhibit a series of biological properties that influence the human in a health-promoting manner. Evidence suggests that people can benefit from plant phenolics obtained either by the diet or through skin application, because they can alleviate symptoms and inhibit the development of various skin disorders. Due to their natural origin and low toxicity, phenolic compounds are a promising tool in eliminating the causes and effects of skin aging, skin diseases, and skin damage, including wounds and burns. Polyphenols also act protectively and help prevent or attenuate the progression of certain skin disorders, both embarrassing minor problems (e.g., wrinkles, acne) or serious, potentially life-threatening diseases such as cancer. This paper reviews the latest reports on the potential therapy of skin disorders through treatment with phenolic compounds, considering mostly a single specific compound or a combination of compounds in a plant extract.

The Potential of Plant Phenolics in Prevention and Therapy of Skin Disorders

Chlorogenic acid-mediated gel formation of oxidatively stressed myofibrillar protein.

Ultrasound assisted extraction (UAE) is widely used in recent times for its benefits, but it is difficult to find literature that comprehensively addresses the effect of UAE-specific parameters such as temperature, frequency, power, solvent type, and solvent to material ratio on extracted compounds and their functionality. There is no review done so far on the effects of all UAE parameters on polyphenol extracts to guide the design of extraction protocols. This review therefore focuses on the effects of UAE parameters on the yield and composition, as well as the effects of the UAE on the antioxidant, anticancer, and antimicrobial properties of phenolic extracts. Higher extraction temperatures above 50 °C are degradative to polyphenols in extracts; lower frequencies within the power ultrasound range below 40 kHz are most effective; polyphenol yield generally increases with increasing power, but with a threshold, beyond which no significant increase is observed; and higher ultrasound power produces free hydroxyl radicals which degrade polyphenols, especially in the presence of high water content. A comparative assessment of literature showed that, UAE does not only contribute to increased extraction yield of polyphenols, but also better preserves and increases the biological activity of polyphenol extracts compared to traditional maceration and Soxhlet extraction. A full picture of UAE is given to serve as a reference material on the control of UAE parameters for desired results and efficiency.

The effects of ultrasound assisted extraction on yield, antioxidant, anticancer and antimicrobial activity of polyphenol extracts: A review

Common beans are a staple food and the major source of iron for populations in Eastern Africa and Latin America. Bean iron concentration is high and can be further increased by biofortification. A major constraint to bean iron biofortification is low iron absorption, attributed to inhibitory compounds such as phytic acid (PA) and polyphenol(s) (PP). We have evaluated the usefulness of the common bean as a vehicle for iron biofortification. High iron concentrations and wide genetic variability have enabled plant breeders to develop high iron bean varieties (up to 10 mg/100 g). PA concentrations in beans are high and tend to increase with iron biofortification. Short-term human isotope studies indicate that iron absorption from beans is low, PA is the major inhibitor, and bean PP play a minor role. Multiple composite meal studies indicate that decreasing the PA level in the biofortified varieties substantially increases iron absorption. Fractional iron absorption from composite meals was 4%–7% in iron deficient women; thus the consumption of 100 g biofortified beans/day would provide about 30%–50% of their daily iron requirement. Beans are a good vehicle for iron biofortification, and regular high consumption would be expected to help combat iron deficiency (ID).

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Review: The Potential of the Common Bean (Phaseolus vulgaris) as a Vehicle for Iron Biofortification

Urbanization, emergence, and prominence of diseases and ailments have led to conscious and deliberate consumption of health beneficial foods. Whole grain (WG) cereals are one type of food with an array of nutritionally important and healthy constituents, including carotenoids, inulin, β-glucan, lignans, vitamin E-related compounds, tocols, phytosterols, and phenolic compounds, which are beneficial for human consumption. They not only provide nutrition, but also confer health promoting effects in food, such as anti-carcinogenic, anti-microbial, and antioxidant properties. Fermentation is a viable processing technique to transform whole grains in edible foods since it is an affordable, less complicated technique, which not only transforms whole grains but also increases nutrient bioavailability and positively alters the levels of health-promoting components (particularly antioxidants) in derived whole grain products. This review addresses the impact of fermentation on phenolic compounds and antioxidant activities with most available studies indicating an increase in these health beneficial constituents. Such increases are mostly due to breakdown of the cereal cell wall and subsequent activities of enzymes that lead to the liberation of bound phenolic compounds, which increase antioxidant activities. In addition to the improvement of these valuable constituents, increasing the consumption of fermented whole grain cereals would be vital for the world’s ever-growing population. Concerted efforts and adequate strategic synergy between concerned stakeholders (researchers, food industry, and government/policy makers) are still required in this regard to encourage consumption and dispel negative presumptions about whole grain foods.

Impact of Fermentation on the Phenolic Compounds and Antioxidant Activity of Whole Cereal Grains: A Mini Review.

Flavonoids and phenolic acids make up one of the most pervasive groups of plant phenolics. Due to their importance in plants and human health, it would be useful to have a better understanding of flavonoid concentration and biological activities that could indicate their potentials as therapeutic agents, and also for predicting and controlling the quality of medicinal herbs. Plants and herbs consumed by humans may contain thousands of different phenolic acid and flavonoid components. The effect of dietary phenolics is currently of great interest due to their antioxidative and possible anticarcinogenic activities. Phenolic acids and flavonoids also function as reducing agents, free radical scavengers, and quenchers of singlet oxygen formation. In addition, flavonoids and phenolic acids components play important roles in the control of cancer and other human diseases.

	 

	Key words: Flavonoids, phenolic acids, biological activities, antioxidative, anticarcinogenic.

/pdf/flavonoids-and-phenolic-acids-role-and-biochemical-activity-58yik48cd9.pdf

Flavonoids and phenolic acids: Role and biochemical activity in plants and human

Extracts of leaves and rhizomes of two varieties (Halia Bara and Halia Bentong) of Malaysian young ginger (Zingiber officinale) grown under different shade net (0 and 60%) were examined as potential sources of phenolics and flavonoids compounds for antioxidant activities. High performance liquid chromatography (HPLC) with UV detection was employed for the identification and quantification of the polyphenolic compounds (flavonoids and phenolic acids). Flavonoid compounds (quercetin, apigenin, luteolin, and myricetin) and phenolic acids (gallic acid, vanillic acid, ferulic acid, tannic acid and caffeic acid) were identified with different concentration in leaves and rhizomes of ginger varieties. The most abundant phenolic acid in ginger was gallic acid, and flavonoids were quercetin and apigenin. Accordingly, accumulations of flavonoids in the leaves were high under 60% shade, while most phenolic acids were observed in the rhizomes under 0% shade. Furthermore, caffeic acid was only detected from ginger grown under 0% shade, while tannic acid only accumulated in the leaves of ginger grown under 60% shade level. The results indicated phenolic acids and flavonoids absolutely light dependent and them biosynthetic rate is related to light intensity. Additionally, this study also validated Halia Bara and Halia Bentong medicinal potential based on polyphenolics compound.

	 

	Key words: High performance liquid chromatography, shade, flavonoids, phenolic acids, Halia Bentong, Halia Bara.

https://www.academicjournals.org/article/article1380712999_Ghasemzadeh and Ghasemzadeh.pdf

Effects of shading on synthesis and accumulation of polyphenolic compounds in ginger (Zingiber officinale Roscoe) varieties

In this study, the effects of some important factors such as concentration of solvent, material ratio, temperature and time was investigated on the contents of flavonoids present in the mulberry leaves. Central composite rotatable design (CCRD) was performed to optimize the extraction parameters for assessing maximum yield of total flavonoid content (TFC) from mulberry leaves. The range of the variables, namely methanol concentration (20 to 100%, v/v), extraction temperature (40 to 80°C), material/solvent ratio (1:5 to 1:25) and extraction time (1 to 3 h) were identified by a first set of single factor experiments. The actual values of the independent variables implicit at five levels were selected based on the results of single factor experiments. The optimum conditions for extraction of TFC were found to be at methanol concentration 81.36%, extraction temperature 36.4°C, extraction time 2.37 h and material/solvent ratio 1:15. Under these optimized conditions maximum yield of TFC was 3.36 mg/g dry weight, which was in close agreement with predicated values (3.382 mg/g dry weight), in consequence representing the suitability of the models developed in optimizing the extraction conditions.

	 

	Key words: Total flavonoids, mulberry (Morus alba L.) leaves, models, central composite rotatable design.

Neda Ghasemzadeh

Papers

Flavonoids and phenolic acids: Role and biochemical activity in plants and human

Effects of shading on synthesis and accumulation of polyphenolic compounds in ginger (Zingiber officinale Roscoe) varieties

Optimization of flavonoids extraction process from mulberry (Morus alba L.) leaves