Recent Developments in Polyphenol Applications on Human Health: A Review with Current Knowledge.

Polyphenol has been used in treatment for some health disorders due to their diverse health promoting properties. These compounds can reduce the impacts of oxidation on the human body, prevent the organs and cell structure against deterioration and protect their functional integrity. The health promoting abilities are attributed to their high bioactivity imparting them high antioxidative, antihypertensive, immunomodulatory, antimicrobial, and antiviral activity, as well as anticancer properties. The application of polyphenols such as flavonoids, catechin, tannins, and phenolic acids in the food industry as bio-preservative substances for foods and beverages can exert a superb activity on the inhibition of oxidative stress via different types of mechanisms. In this review, the detailed classification of polyphenolic compunds and their important bioactivity with special focus on human health are addressed. Additionally, their ability to inhibit SARS-CoV-2 could be used as alternative therapy to treat COVID patients. Inclusions of polyphenolic compounds in various foods have demonstrated their ability to extend shelf life and they positive impacts on human health (antioxidative, antihypertensive, immunomodulatory, antimicrobial, anticancer). Additionally, their ability to inhibit the SARS-CoV-2 virus has been reported. Considering their natural occurrence and GRAS status they are highly recommended in food.

Black soybean (Glycine max (L.) Merr.): paving the way toward new nutraceutical.

Black soybean (BS) is a nutritious legume that is high in proteins, essential amino acids, dietary fiber, vitamins, minerals, anthocyanins, phenolic acids, isoflavones, and flavones. Traditional approaches for extracting BS bioactive compounds are commonly employed because they are simple and inexpensive, but they use toxic solvents and have lower yields. As a result, new extraction techniques have been developed, such as microwave, ultrasound, and enzyme-assisted extraction. Modern approaches are less harmful to the environment, are faster, and produce higher yields. The major anthocyanin in the BS seed coat was discovered as cyanidin-3-O-glucoside, accounting for nearly 75% of the total anthocyanins. BS and its seed coat also contains phenolic acids (p-hydroxybenzoic, gallic, vanillin, syringic acid), isoflavones (daidzein, glycitein and genistein), flavones, flavonols, flavanones, and flavanols. Bioactive compounds present in BS exhibit antioxidant, anti-cancerous, anti-diabetic, anti-obesity, anti-inflammatory, cardio and neuroprotective activities. The characterization and biological activity investigation of these bioactive compounds has provided researchers and food manufacturers with valuable information for developing functional food products and nutraceutical ingredients. In this review, the nutritional makeup of BS is reviewed, and the paper seeks to provide an insight of bioactive compound extraction methods as well as bioactive compounds identified by various researchers. The biological activities of BS extracts and their potential applications in food products (noodles), biodegradable films (pH sensitive film), and therapeutic applications (wound healing and anti-inflammation) are also discussed in the study. Therefore, BS have enormous potential for use in developing functional foods and nutraceutical components. This is the first review of its sort to describe and explain various extraction methodologies and characterization of bioactives, as well as their biological activity recorded in diverse works of literature, making it possible for food manufacturers and scientists to get a quick overview.

Onion (Allium cepa L.) peels: A review on bioactive compounds and biomedical activities.

Huge quantities of byproducts/wastes generated in onion processing are usually discarded, but they are excellent sources of bioactive compounds and phytochemicals. However, with growing interest in the sustainable use of resources and the circular economy to reduce adverse impacts on the environment, food processing wastes such as onion peel/skin can be extracted and employed as inputs in developing or reformulating nutrient supplements, and pharmacological drugs. This review highlights major bioactive components, especially total phenolics, total flavonoid, quercetin and its derivatives present in onion peel/skin and their therapeutic applications as cardioprotective, neuroprotective, antiobesity, antidiabetic, anticancer and antimicrobial agents. The present review emphasized that onion peel is one of the important agricultural by-products which is rich in bioactive compounds and can be utilized as health promoting ingredient especially in pharmacological and biomedical fields. Thus, with increasing burden of life style disorders/non-communicable diseases, finding suitable natural alternative for their treatment is one major concern of the researchers and onion peel and its extract can be exploited as a prime ingredient.

Use of Industrial Wastes as Sustainable Nutrient Sources for Bacterial Cellulose (BC) Production: Mechanism, Advances, and Future Perspectives.

A novel nanomaterial, bacterial cellulose (BC), has become noteworthy recently due to its better physicochemical properties and biodegradability, which are desirable for various applications. Since cost is a significant limitation in the production of cellulose, current efforts are focused on the use of industrial waste as a cost-effective substrate for the synthesis of BC or microbial cellulose. The utilization of industrial wastes and byproduct streams as fermentation media could improve the cost-competitiveness of BC production. This paper examines the feasibility of using typical wastes generated by industry sectors as sources of nutrients (carbon and nitrogen) for the commercial-scale production of BC. Numerous preliminary findings in the literature data have revealed the potential to yield a high concentration of BC from various industrial wastes. These findings indicated the need to optimize culture conditions, aiming for improved large-scale production of BC from waste streams.

Tomato (Solanum lycopersicum L.) seed: A review on bioactives and biomedical activities.

The processing of tomato fruit into puree, juices, ketchup, sauces, and dried powders generates a significant amount of waste in the form of tomato pomace, which includes seeds and skin. Tomato processing by-products, particularly seeds, are reservoirs of health-promoting macromolecules, such as proteins (bioactive peptides), carotenoids (lycopene), polysaccharides (pectin), phytochemicals (flavonoids), and vitamins (α-tocopherol). Health-promoting properties make these bioactive components suitable candidates for the development of novel food and nutraceutical products. This review comprehensively demonstrates the bioactive compounds of tomato seeds along with diverse biomedical activities of tomato seed extract (TSE) for treating cardiovascular ailments, neurological disorders, and act as antioxidant, anticancer, and antimicrobial agent. Utilization of bioactive components can improve the economic feasibility of the tomato processing industry and may help to reduce the environmental pollution generated by tomato by-products.

Beneficial Role of Antioxidant Secondary Metabolites from Medicinal Plants in Maintaining Oral Health.

Plant-derived phytochemicals have been touted as viable substitutes in a variety of diseases. All over the world, dentists have turned to natural remedies for dental cure due to the negative possessions of certain antibacterial mediators used in dentistry. Antimicrobial and other drugs are currently in use, but they show some side effects. Since ancient times, antioxidant EOs have been used for different ailments and have grown in popularity over time. Several in vitro, in vivo, and clinical trials have shown the safety and effectiveness of antioxidant essential oils (EOs) in oral health obtained from medicinal plants. The current review of literature provides a summary of secondary metabolites, more specifically EOs from 20 most commonly used medicinal plants and their applications in maintaining oral health. Dental caries and periodontal diseases are the most common and preventable global infectious diseases, with diseases of the oral cavity being considered major diseases affecting a person's health. Several clinical studies have shown a connection between oral diseases and oral microbiota. This review discusses the role of antioxidant secondary metabolites in inhibiting the growth of oral pathogens and reducing the formation of dental plaque, and as well as reducing the symptoms of oral diseases. This review article contributes a basic outline of essential oils and their healing actions.

Delineating the inherent functional descriptors and biofunctionalities of pectic polysaccharides.

Pectin is a plant-based heteropolysaccharide macromolecule predominantly found in the cell wall of plants. Pectin is commercially extracted from apple pomace, citrus peels and sugar beet pulp and is widely used in the food industry as a stabilizer, emulsifier, encapsulant, and gelling agent. This review highlights various parameters considered important for describing the inherent properties and biofunctionalities of pectins in food systems. These inherent descriptors include monosaccharide composition, galacturonic acid content, degree of esterification, molecular weight, structural morphology, functional group analysis, and functional properties, such as water and oil holding capacity, emulsification, foaming capacity, foam stability, and viscosity. In this study, we also delineate their potential as a nutraceutical, prebiotic, and carrier for bioactive compounds. The biofunctionalities of pectin as an anticancer, antioxidant, lipid-lowering, and antidiabetic agent are also conceptually elaborated in the current review. The multidimensional characteristics of pectin make it a potential candidate for use in food and biomedical science.

Solid state fermentation of fenugreek (Trigonella foenum-graecum): implications on bioactive compounds, mineral content and in vitro bioavailability.

In the present study, solid-state fermentation (SSF) of four fenugreek cultivars viz. HM-57, AFG-2, RMT-1 and RMT-303 were carried out using Aspergillus awamori and its effect on antioxidant properties, phenolic content and bioactive compounds were studied. Macro (Ca, K, and Na) as well as micro (Fe, Zn, and Cu) elements and in vitro bioavailability of the unfermented fenugreek (UFF) and Aspergillus-fermented fenugreek (AFF) samples were assessed with standard methods. On 5th day, total phenolic and condensed tannin contents showed significant (p ≤ 0.05) increase for all cultivars. Further, HPLC analysis confirmed formation of some new bioactive (vanillin, benzoic acid and catechin) compounds. Similarly, extracts from all AFF also showed an increase in the antioxidant potential such as inhibition of DPPH, hydroxyl free radical scavenging, reducing power, and total antioxidant capacity up to 5th day of SSF. Mineral in AFF were found with enhanced values when compared with respective UFF. In vitro bioavailability of Fe, Zn and Ca was also improved during SSF. Results from the present study may be helpful to food industry in developing new health foods and may provide a rational for development of functional ingredient in preparation of novel nutraceuticals.

Custard Apple (Annona squamosa L.) Leaves: Nutritional Composition, Phytochemical Profile, and Health-Promoting Biological Activities.

Annona squamosa L. (custard apple) belongs to the family Annonaceae and is an important tropical fruit cultivated in the West Indies, South and Central America, Ecuador, Peru, Brazil, India, Mexico, the Bahamas, Bermuda, and Egypt. Leaves of custard apple plants have been studied for their health benefits, which are attributed to a considerable diversity of phytochemicals. These compounds include phenol-based compounds, e.g., proanthocyanidins, comprising 18 different phenolic compounds, mainly alkaloids and flavonoids. Extracts from Annona squamosa leaves (ASLs) have been studied for their biological activities, including anticancer, antidiabetic, antioxidant, antimicrobial, antiobesity, lipid-lowering, and hepatoprotective functions. In the current article, we discussed the nutritional and phytochemical diversity of ASLs. Additionally, ASL extracts were discussed with respect to their biological activities, which were established by in vivo and in vitro experiments. A survey of the literature based on the phytochemical profile and health-promoting effects of ASLs showed that they can be used as potential ingredients for the development of pharmaceutical drugs and functional foods. Although there are sufficient findings available from in vitro and in vivo investigations, clinical trials are still needed to determine the exact effects of ASL extracts on human health.

Pearl millet grain as an emerging source of starch: A review on its structure, physicochemical properties, functionalization, and industrial applications.

Pearl millet (Pennisetum glaucum (L.) R.Br.) is a sustainable and underutilized starch source, constituting up to 70 % starch in its grain. Pearl millet could be used as a cheaper source of starch as compared to other cereals for developing functional foods. This review is mainly focused on isolation methods, and chemical composition of the pearl millet starch (PMS). Techno-functional characteristics such as; gelatinization, pasting properties, solubility, swelling power, and digestibility to infer wider application of the PMS critically highlighted in the review. Native starches have limited functionalitiesfor food applications due to the instability in developed pastes and gels. A number of modifications (physical, mechanical and enzymatic) have been developed to increase the functionality and to obtain desired characteristics of PMS thus improving its utilization in food applications. Further, the utilization of native as well as modified PMS is also discussed comprehensively. In addition, a number of recommendations to further improve its functionality and increase its application are also discussed.

Recent trends in extraction of plant bioactives using green technologies: A review.

Phenolic compounds from plant sources have significant health-promoting properties and are known to be an integral part of folk and herbal medicines. Consumption of phenolics is known to alleviate the risk of various lifestyle diseases including cancer, cardiovascular, diabetes, and Alzheimer's. In this context, numerous plant crops have been explored and characterized based on phenolic compounds for their use as supplements, nutraceutical, and pharmaceuticals. The present review highlights some important source of bioactive phenolic compounds and novel technologies for their efficient extraction. These techniques include the use of microwave, ultrasound, and supercritical methods. Besides, the review will also highlight the use of response surface methodology (RSM) as a statistical tool for optimizing the recoveries of the phenolic bioactives from plant-based matrices.

Mango (Mangifera indica L.) Leaves: Nutritional Composition, Phytochemical Profile, and Health-Promoting Bioactivities.

Mangifera indica L. belongs to the family of Anacardiaceae and is an important fruit from South and Southeast Asia. India, China, Thailand, Indonesia, Pakistan, Mexico, Brazil, Bangladesh, Nigeria, and the Philippines are among the top mango producer countries. Leaves of the mango plant have been studied for their health benefits, which are attributed to a plethora of phytochemicals such as mangiferin, followed by phenolic acids, benzophenones, and other antioxidants such as flavonoids, ascorbic acid, carotenoids, and tocopherols. The extracts from mango leaves (MLs) have been studied for their biological activities, including anti-cancer, anti-diabetic, anti-oxidant, anti-microbial, anti-obesity, lipid-lowering, hepato-protection, and anti-diarrheal. In the present review, we have elaborated on the nutritional and phytochemical profile of the MLs. Further, various bioactivities of the ML extracts are also critically discussed. Considering the phytochemical profile and beneficial effects of the MLs, they can be used as a potential ingredient for the development of functional foods and pharmaceutical drugs. However, more detailed clinical trials still needed to be conducted for establishing the actual efficacy of the ML extracts.

Rheological, thermal, and structural properties of high-pressure treated Litchi (Litchi chinensis) kernel starch.

Starch isolated from litchi kernel was subjected to high-pressure (HP) treatment at selected pressures (300, 450 and 600 MPa) for 10 min, and evaluated for its rheological, morphological, thermal and structural properties. The amylose content of native litchi kernel starch (LKS) was 17.4%, which increased significantly upon pressurization. The temperature sweep test of the untreated starch sample resulted in the peak G' and G″ values of 3417 and 283 Pa, respectively, and those values decreased after pressurization. Oscillatory rheological measurements showed the frequency dependency of tested starch pastes. Furthermore, the mechanical rigidity of the starch pastes improved with pressure treatment. Morphological studies revealed that starch granule structure remained intact after pressurization; however, pressure >450 MPa resulted in surface roughness and small cavities. HP treatment significantly influenced thermal properties of LKS, in particular at 450 and 600 MPa, where a significant drop in the transition temperatures and enthalpy values were recorded. The HP-treated starch samples exhibited distinct X-ray diffraction pattern of native LKS i.e. the blend of A- and B-type allomorphs with a predominating A-type crystalline structure. Upon pressure treatment, the disappearance of 2θ peak at 5.6° and significant changes in peak intensities confirmed the structural change in the starch matrix.

Evaluation of Cellulolytic Enzyme-Assisted Microwave Extraction of Punica granatum Peel Phenolics and Antioxidant Activity.

Conventional techniques for phenolics extraction from pomegranate (Punica granatum) peel (PP) have several insufficiencies like longer time duration, bioactive degradation, excess use of harmful chemicals and solvents. In the present study, we established the synergistic use of two non-conventional extraction strategies i.e., enzyme-assisted extraction (EAE) using a cellulolytic enzyme preparation (Viscozyme) followed by microwave-assisted extraction (MAE) for efficient recovery of phenolics from PP. This optimized method was individually compared with EAE, MAE, and conventional solvent extraction (CSE) methods for recovering PP phenolics with maximum antioxidant activity (AOA). Extracts were analyzed for AOA using ferric reducing antioxidant power (FRAP) and cupric reducing AOA (CUPRAC) methods. Response surface methodology (RSM), was used as an optimization tool to achieve maximum yield of phenolics and with highest AOA at power 443.5 W, time 131.0 min, and solvent-to-solid ratio 23.6:1. The predicted values for maximum phenolics and AOA obtained through RSM were 305 mg GAE/g, 1788 µmol TE/g (FRAP) and 2641 µmol TE/g (CUPRAC), respectively. Phenolic contents of only 94.6, 165.46, and 197.6 mg GAE/g were achieved through CSE, EAE and MAE, respectively. Here we substantiate the auxiliary role of Viscozyme and microwave treatment in achieving high phenolic content and AOA from PPs. Phenolic rich extracts are known to act as multi-target ligands that inhibit various enzymes involved in diseases like Alzheimer's, Parkinson's, and diabetes mellitus. The extract can be commercially exploited for the development of functional foods, supplements, and natural preservatives.

Kinetic, rheological and thermal studies of flaxseed (Linum usitatissiumum L.) oil and its utilization.

In present study kinetic, thermal and rheological characteristics of oil isolated from flaxseed were studied and because of high content of α-linolenic acid (essential omega-3 fatty acid), flaxseed oil was incorporated in muffins by replacing fat/shortening at different levels (10%, 20%, 30% and 40%). To evaluate rheological behaviour, the experimental data of flow behaviour for flaxseed oil was fitted to Power law model, consistency index (K) and flow behaviour index (n) and Arrhenius parameters (activation energy and frequency factor) were evaluated. The n value of the oil treated at 10, 15, 20, 25 and 30 °C were found between 0.8 to 0.9, which suggested the non-Newtonian fluid behaviour of flaxseed oil. Thermal properties of flaxseed oil was evaluated using DSC (differential scanning calorimetry). The flaxseed oil possessed three endothermic and one shoulder peak. Gas chromatography revealed the fatty acids composition qualitatively and quantitatively and flaxseed oil is dominated by unsaturated fatty acids. Saturated oil was replaced with flaxseed unsaturated fat and results showed that substituting oil with flaxseed fat at level upto 20% produced muffins possessed the better texture, colour, aroma, mouth feel and overall quality score. Practical application: Modern diet lifestyle demands of healthy natural foods represent a challenge for food manufacturers to lead towards the healthy new trends. Fats imparts lubrication, texture, flavour and acceptability therefore used as major ingredients in bakery goods. Fats contains saturated fatty and dietary intake of saturated fatty acids in excess amount leads to many health disorders. Therefore, substitution of saturated fatty acid with PUFAs (omega-3 and omega-6) for the protection against diseases and metabolic disorders may be a solution for healthy and nutritious product development.

Quantification of phenolic acids and antioxidant potential of wheat rusks as influenced by partial replacement with barley flour.

This study was investigated to evaluate the phenolic acid composition, antioxidant potential and acceptance of rusk prepared by the progressive replacement of wheat flour with barley flour. The wheat-barley blends rusks were also evaluated for their pasting and sensorial properties. The pasting characteristics of wheat flour was influenced by barley flour incorporation with a increase in peak and final viscosity values with increasing amount of barley flour. The results revealed that incorporation of barley flour into wheat flour improved the nutritional and bioactive compounds profile. The free radical scavenging activities towards DPPH and ABTS+ was found to be higher for wheat-barley blends rusk in comparison with wheat rusk. As evident from total phenolic content, total flavonoids contents and antioxidant activities, barley flour was found to be rich in bioactive compounds in comparison with wheat flour. Supplementation of rusks with 30% barley flour were suggested to be nutritionally superior with an acceptable sensory score and is a successful approach to enrich rusks with nutrients.

Enhancing the functionality of chitosan- and alginate-based active edible coatings/films for the preservation of fruits and vegetables: A review.

A number of studies have established the potential of chitosan and alginate-based edible film/coatings for preserving the quality attributes of fruits and vegetables. Findings demonstrate that these films/coatings act as a barrier on the surface of fruits and vegetables which causes higher moisture and water retention, create favourable micro-environments by optimizing the concentration of gases and delays ripening. Sincere efforts are being further made to improve the efficiency of edible films using functional additives such as phenolics, essential oils (EOs) and nano-forms. These additives have unlocked a new dimension for enhancing functional properties of alginate/chitosan-based films. These functional compounds are now emerging as an important component of edible films/coatings for prolonging shelf-life of fruits and vegetables. The present review comprehensively elaborates recent studies on functional additives and their mechanism of action. Here we also establish their proficiency in extending quality and shelf-life of various fruits including guava, pear, blueberries and vegetables like cucumber, capsicum and mushroom. Principles behind antimicrobial and antioxidant activities of additives in preventing the food spoilage are also reviewed. Competency of phenolics, EOs and nano-forms in extending the shelf-life without affecting the nutritional properties and safety aspects of the fruits and vegetables still require further attention.

Functional, thermal and rheological behavior of fenugreek (Trigonella foenum-graecum L.) gums from different cultivars: A comparative study.

Fenugreek gum (FG) was isolated from six different Indian fenugreek cultivars and studied for their functional, structural, thermal and rheological attributes. The highest yield (13.5%) was observed for cultivar RMT-365. All galactomannans depicted good water and oil holding capacities ranging from 2009 ± 5.5 to 2099.9 ± 2.5% and 523.5 ± 3.5 to 553.0 ± 2.0%, respectively. DSC thermograms of FG revealed the presence of one endothermic and one exothermic peak. For endothermic transition of gums from different cultivars, enthalpy change (Δ Ha) ranged from 234.2 to 351.8 J/g while for exothermic transition, Δ Ha values ranged from 72.0 to 102.1 J/g, much lower as compared with endothermic peak. The effect of variable shear rate on viscosity of 1% FG solutions showed their shear thinning behaviors for all the cultivars, whereby the viscosity decreased with increasing shear rate. Frequency sweep tests indicated typical viscoelastic fluid behavior for all the gum solutions. Increase in the magnitude of G' and G″ of FG solutions was observed with an increase in frequency. A detailed understanding of different chemical, functional and thermal properties of FG could surely enlarge the radius of its application and eventually aid in its utilization in different food, pharma and cosmetic products.

Effect of γ-radiation on physico-chemical, morphological and thermal characteristics of lotus seed (Nelumbo nucifera) starch.

Native and gamma (γ) irradiated lotus seed starches were studied for their physicochemical, thermal, pasting and morphological properties. Upon gamma irradiation of 5, 10, 15 and 20 kGy, amylose content of starches was decreased as the dose of irradiation was increased. Lotus seeds starch granules had bimodal size distribution varying in size from small to large. Observation under scanning electron microscope (SEM) showed that at low dose of irradiation (5, 10kGy), no significant changes were observed in shape and size. However, minor alterations were notice during treatment of 15kGy and 20 kGy, which included roughness. Irradiation significantly decreased the pasting properties (peak, trough, final and setback viscosities) of the starch. For native starch, To, Tp, and Tc of 137.44 °C, 138.29 °C and 143.21 °C and 169.51 °C, 169.72 °C, and 177.73 °C respectively was observed for first and second peak. Upon irradiation, the gelatinization temperatures were decreased. The irradiated starch showed no change in diffraction pattern compared to native lotus seed starch but a dose-dependent decrease in relative crystallinity was observed.

Oat starch: Physico-chemical, morphological, rheological characteristics and its applications - A review.

Oat starch is getting attention owing to its usefulness and potential in a number of food and non-food applications. Starch is by far the main component of oat grains and possesses some unique chemical, physical, and structural properties when compared with other cereal starches. Oat starch offers untypical properties such as small size of granules, well-developed granule surface and high lipid content. Variation in amylose and amylopectin proportion along with the properties associated with the amylopectin molecule makes diversity in composition of oat starch. The pasting and rheological properties of oat starches control food product quality. This review articles outlines the recent developments in understanding of the starch isolation, chemical composition, morphology, pasting, rheological and thermal characteristics and various application of oat starch. Potential applications of oat starches are also reviewed.