Extraction, characterization and immunomodulatory property of pectic polysaccharide from pomegranate peels: Enzymatic vs conventional approach

Ultrasonic depolymerization of pomegranate peel pectin: Effect of sonication time on antioxidant, α-amylase inhibitory, and prebiotic properties

This study aimed to investigate the effects of ultrasonic treatment time (5-30 min) on the structural characteristics, antioxidant, α-amylase inhibitory, and prebiotic properties of pomegranate peel pectin (PPP). The extracted PPP was rich in galacturonic acid (64.27 %) and exhibited a high degree of esterification (DE, 61.7 %), with an average molecular weight (Mw) of 135.6 kDa. The Mw, particle size, and DE of ultrasonic-treated PPPs (U-PPPs) significantly decreased compared to the PPP. FTIR analysis revealed that the intensity of the peak at ∼1730-1720 cm-1 weakened with prolonged treatment time. The total phenol content, antioxidant activity, and α-amylase inhibition of U-PPPs were enhanced compared to PPP. Both PPP and U-PPP treated for 30 min promoted the growth of Bifidobacterium longum and Lactobacillus casei, with U-PPP-30 showing a greater preference over PPP and inulin. In conclusion, ultrasonic treatment represents a promising approach to depolymerization aimed at enhancing the biological activities of pectin.

PPARγ-mediated amelioration of lipid metabolism abnormality by kaempferol

Kaempferol can exert biological functions by regulating various signaling pathways. This study evaluated the ameliorative effect of kaempferol on lipid accumulation using oleic acid and palmitic acid-treated HepG2 cells and high-fat diet mice. In vitro oil red O staining showed that kaempferol treatment improved lipid accumulation (p < 0.001 for TG content and p < 0.05 for TC content). Immunofluorescence, Western blot analysis and RT-qPCR showed that kaempferol could promote nuclear translocation of PPARγ and reduce the expression of PPARγ, C/EBPβ, and SREBP-1c. Dietary intervention with kaempferol could reduce the lipid accumulation in hepatocytes and inflammatory cell infiltration, as well as attenuated serum levels of IL-6 and TNF-α in HFD-fed mice (p < 0.001 for IL-6 and p < 0.01 for TNF-α at kaempferol 60 mg/kg/d). Meanwhile, histopathological examination revealed that there was no substantial damage or distinct inflammation lesions in organs at the experimental dose, including the heart, lung, kidney, and spleen. The aforementioned research findings can serve as references for further preclinical investigations on the potential of kaempferol to mitigate lipid accumulation.

Effect of high-pressure-homogenisation on the interaction between pomegranate peel pectin fractions and anthocyanins in acidic environment

In this study, changes in the basic composition and structural characterisation of water-soluble pectin (WSP), homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) from pomegranate peel were investigated after high-pressure-homogenisation (HPH) at 50 MPa and 300 MPa. The interactions between three pectin and anthocyanin (ACN) complex were also studied. The three pectin fractions were mainly composed of galacturonic acid (34.95%-87.69%), all with low degrees of methyl-esterification ≤41.20%. HPH at 300 MPa increased the binding ratios of ACN to three pectin fractions by 34.22%-34.59%. Changes in the structural characterisation results of pectin confirmed that the depolymerisation and breakdown of the side chains of pectin after HPH promoted electrostatic interactions, hydrogen bond and hydrophobic interaction between pectin and ACN. Correspondingly, the thermal and storage stabilities of ACN in the complex was boosted after HPH at 300 MPa. This study provides insights into the interaction between pectin and ACN under HPH.

Punica granatum L. polysaccharides: A review on extraction, structural characteristics and bioactivities

Punica granatum L., commonly known as pomegranate, is native to Afghanistan and Iran, and today widely cultivated all over the world. Pomegranate polysaccharides are one of the most important bioactive components of P. granatum, which have a wide range of beneficial biological activities, such as anticancer, immunostimulatory, hepatoprotection, anti-psoriasis and antioxidation. Hot water extraction is currently the most commonly used method to isolate pomegranate polysaccharides. The structural characteristics of pomegranate polysaccharides have been extensively investigated through various advanced modern analytical techniques. This review focuses on the extraction, purification, structural characteristics, biological activities and structure-activity relationships of polysaccharides from Punica granatum. The aim of this article is to comprehensively and systematically summarize recent information of polysaccharides from Punica granatum and to serve as a basis for further research and development as therapeutic agents and functional foods.

Polysaccharides in fruits: Biological activities, structures, and structure-activity relationships and influencing factors-A review

Fruits are a rich source of polysaccharides, and an increasing number of studies have shown that polysaccharides from fruits have a wide range of biological functions. Here, we thoroughly review recent advances in the study of the bioactivities, structures, and structure-activity relationships of fruit polysaccharides, especially highlighting the structure-activity influencing factors such as extraction methods and chemical modifications. Different extraction methods cause differences in the primary structures of polysaccharides, which in turn lead to different polysaccharide biological activities. Differences in the degree of modification, molecular weight, substitution position, and chain conformation caused by chemical modification can all affect the biological activities of fruit polysaccharides. Furthermore, we summarize the applications of fruit polysaccharides in the fields of pharmacy and medicine, foods, cosmetics, and materials. The challenges and perspectives for fruit polysaccharide research are also discussed.

Phytochemical profile, nutritional composition of pomegranate peel and peel extract as a potential source of nutraceutical: A comprehensive review

The current study focuses on Punica granatum L. (pomegranate) peel and peel extract and their use as functional foods, food additives, or physiologically active constituents in nutraceutical formulations. The pomegranate peel extract is a good source of bioactive substances needed for the biological activity of the fruit, including phenolic acids, minerals, flavonoids (anthocyanins), and hydrolyzable tannins (gallic acid). The macromolecules found in pomegranate peel and peel extract have been recommended as substitutes for synthetic nutraceuticals, food additives, and chemo-preventive agents because of their well-known ethno-medical significance and chemical properties. Moreover, considering the promises for both their health-promoting activities and chemical properties, the dietary and nutraceutical significance of pomegranate peel and pomegranate peel extract appears to be underestimated. The present review article details their nutritional composition, phytochemical profile, food applications, nutraceutical action, and health benefits.

Physicochemical, structural, and functional characterization of pectin extracted from quince and pomegranate peel: A comparative study

Pectin's physicochemical, structural, and functional characteristics vary widely depending on the source of extraction. In this study, pectins were extracted from seedless quince and pomegranate peel, and their physicochemical, structural, and functional properties were investigated. A Box-Behnken Design with three factors and three levels was applied to optimize the pectin extraction yield from each matrix. As a result, the best extraction yields for quince pectin (QP) and pomegranate peel pectin (PPP) were 11.44 and 12.08 % (w/w), respectively. Both extracted pectins exhibit a linear structure, with the homogalacturonan domain dominating the rhamnogalacturonan I. Both pectins are highly methyl-esterified (DM > 69 %) with a higher degree of acetylation for PPP than QP, with 12 and 8 %, respectively. Unlike QP, PPP has a narrow, homogenous distribution and greater molecular weight (120 kDa). Regarding functionality, 1 g of QP could retain 4.92 g of water, and both pectin emulsions were more stable at room temperature than at 4 °C. When the concentration of QP is increased, rheological measurements demonstrate that it exhibits pseudoplastic behavior. Finally, QP can be used as a thickener, whereas PPP can be utilized as starting material for chemical changes to create multifunctional pectins.

Extraction of pectin from watermelon and pomegranate peels with different methods and its application in ice cream as an emulsifier

Pectin extraction from watermelon peel (WP) and pomegranate peel (PP) was carried out using three different extraction methods: classical solvent extraction (CSE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). Extraction parameters (pH, temperature, time, and speed/amplitude/power) were optimized to target maximum crude pectin yield (CPY), while the sample-to-solvent ratio (SS) was determined to be fixed at 1:10 w/v at all experiments. CPY was increased by low pH, high temperature, and long time. The pectins obtained at optimum conditions were characterized regarding the physicochemical and rheological properties, and the pectin solutions were found to be typical pseudoplastic fluids. WP pectin extracted with MAE and PP pectin extracted with UAE were determined to have the best emulsifying properties and added to the ice cream formulations. MAE had the maximum CPY of 9.40% for WP (pH = 1.3, 6 min, 596 W) and the best emulsifying properties. UAE had the best emulsifying properties for PP and the CPY was 11.56% in conditions of pH = 1.5, a temperature of 69°C, an extraction time of 29 min, and a 32% amplitude. The use of PP pectin resulted in a significant increase in the apparent viscosity of ice cream mix and also the first dripping time and the hardness of ice cream over commercial emulsifier. Melting properties and hardness values of ice cream with WP pectin were comparatively closer to those of ice cream with commercial emulsifier. On the other hand, the first dripping time and hardness value of ice cream with PP pectin having 60.25 min and 3.84 N, respectively, were higher than those of commercial ice cream having 53.75 min and 2.14 N, respectively. Practical Application: The utilization of WP and PP, which are good sources for pectin production, benefits both a sustainable environment and a sustainable food industry. Pectin extracted from WP and PP as an emulsifier in ice cream can ensure the production of ice creams with good melting properties. Pectin can be used as a healthy, sustainable, and economical alternative emulsifier in the ice cream industry.

Pectin-like polysaccharide extracted from leaves Crataeva tapia promotes antioxidant, immunomodulatory and emulsifiers applied in therapeutic formulations

The objective of this work was to isolate a polysaccharide similar to pectin from Crataeva tapia leaves, not yet reported in the literature, and to evaluate its antioxidant, cytotoxic and immunomodulatory profile. Pectin was extracted from the leaves in three stages, organic solvent followed by acidified water and ethanol precipitation. With the pectin obtained, the physicochemical characterization of the molecule was carried out using high-performance liquid chromatography, Fourier-transform infrared spectroscopy, nuclear magnetic resonance (13C and 1H) and different thermal and elemental analysis. Furthermore, the antioxidant activities were evaluated in vitro, and using human peripheral blood mononuclear cell culture, cytotoxicity and immunostimulatory actions were investigated. Physical and chemical analyses showed characteristic signs of pectin. Antioxidant activity tests showed that pectin had moderate to low antioxidant activity. Furthermore, pectin did not affect the viability of erythrocytes and PBMC and induced an immunostimulatory state when it promoted the production of cytokines IL-6, IL-10 and TNF-α and increased the activation of CD8 + T lymphocytes. This study showed that pectin from Crataeva tapia is not cytotoxic and promoted a pro-inflammatory profile in peripheral blood mononuclear cell with application as an immunostimulating and emulsifying compound.

Current progress in valorization of food processing waste and by-products for pectin extraction

Food processing waste and by-products such as peel of citrus fruit, melon, mango, pineapple, etc. and fruit pomace can be utilized for manufacturing of several high-value products. Valorization of these waste and by-products for extraction of pectin, can help offset growing environmental concerns, facilitate value-addition of by-products and their sustainable uses. Pectin has many applications in food industries such as gelling, thickening, stabilizing, and emulsifying agent, and as a dietary fibre. This review elaborates on various conventional and advanced, sustainable pectin extraction techniques, and paints a comparative picture between them considering extraction efficiency, quality, and functionality of the pectin. Conventional acid, alkali, and chelating agents-assisted extraction have been profusely used for pectin extraction, but advanced extraction technologies e.g., enzyme, microwave, supercritical water, ultrasonication, pulse electric field and high-pressure extraction are preferred due to less energy consumption, better quality product, higher yield, and minimal or no generation of harmful effluent.

Insights into the Oxidative Stress Alleviation Potential of Enzymatically Prepared Dendrobium officinale Polysaccharides

(1) Background: The extraction parameters can dramatically alter the extraction rate and biological activity of polysaccharides. (2) Methods: Here, an enzyme-assisted extraction (EAE) was employed to extract D. officinale polysaccharides (DOPs), and its optimal extraction conditions were established by single-factor and Box-Behnken design (BBD) experiments. Further, on the basis of in vitro antioxidant capacity, the paraquat (PQ)-induced oxidative stress of Caenorhabditis elegans (C. elegans) was chosen as a research model to explore the antioxidant activity of DOPs. (3) Results: The results showed that the extraction yield of DOPs reached 48.66% ± 1.04% under the optimal condition. In vitro experiments had shown that DOPs have considerable ABTS⁺ radical scavenging capacity (EC50 = 7.27 mg/mL), hydroxyl radical scavenging capacity (EC50 = 1.61 mg/mL), and metal chelating power (EC50 = 8.31 mg/mL). Furthermore, in vivo experiments indicated that DOPs (0.25 mg/mL) significantly prolonged the lifespan, increased antioxidant enzyme activity, and upregulated the expression of daf-16 (>5.6-fold), skn-1 (>5.2-fold), and sir-2.1 (>2.3-fold) of C. elegans. (4) Conclusions: DOPs can be efficiently extracted by EAE and are effective in the reduction of oxidative stress levels in C. elegans.

Sustainable approaches on industrial food wastes to value-added products - A review on extraction methods, characterizations, and its biomedical applications

The concept of zero waste discharge has been gaining importance in recent years towards attaining a sustainable environment. Fruit processing industries generate millions of tons of byproducts like fruit peels and seeds, and their disposal poses an environmental threat. The concept of extracting value-added bioactive compounds from bio-waste is an excellent opportunity to mitigate environmental issues. To date, significant research has been carried out on the extraction of essential biomolecules, particularly polysaccharides from waste generated by fruit processing industries. In this review article, we aim to summarize the different extraction methodologies, characterization methods, and biomedical applications of polysaccharides extracted from seeds and peels of different fruit sources. The review also focuses on the general scheme of extraction of polysaccharides from fruit waste with special emphasis on various methods used in extraction. Also, the various types of polysaccharides obtained from fruit processing industrial wastes are explained in consonance with the important techniques related to the structural elucidation of polysaccharides obtained from seed and peel waste. The use of seed polysaccharides as pharmaceutical excipients and the application of peel polysaccharides possessing biological activities are also elaborated.

Novel Pectic Polysaccharides Isolated from Immature Honey Pomelo Fruit with High Immunomodulatory Activity

A novel pectic polysaccharide (HPP-1) with high immunomodulatory activity was extracted and isolated from the immature honey pomelo fruit (Citrus grandis). Characterization of its chemical structure indicated that HPP-1 had a molecular weight of 59,024 D. In addition, HPP-1 was primarily composed of rhamnose, arabinose, fucose, mannose, and galactose at a molar ratio of 1.00:11.12:2.26:0.56:6.40. Fourier-transform infrared spectroscopy, periodic acid oxidation, and Smith degradation results showed that HPP-1 had α- and β-glycosidic linkages and 1 → 2, 1 → 4, 1 → 6, and 1 → 3 glycosidic bonds. ¹³C NMR and ¹H NMR analyses revealed that the main glycogroups included 1,4-D-GalA, 1,6-β-D-Gal, 1,6-β-D-Man, 1,3-α-L-Ara, and 1,2-α-L-Rha. Immunomodulatory bioactivity analysis using a macrophage RAW264.7 model in vitro revealed that NO, TNF-α, and IL-6 secretions were all considerably increased by HPP-1. Moreover, RT-PCR results showed that HPP-1-induced iNOS, TNF-α, and IL-6 expression was significantly increased in macrophages. HPP-1-mediated activation in macrophages was due to the stimulation of the NF-κB and MAPK signaling pathways based on western blot analyses. HPP-1 extracted from immature honey pomelo fruit has potential applications as an immunomodulatory supplement.

Immunostimulatory effects of a polysaccharide from Pimpinella anisum seeds on RAW264.7 and NK-92 cells

Polysaccharides from Pimpinella anisum were isolated using water at elevated temperature and DEAE Sepharose FF chromatography to examine their chemical structure and activation capacity on immune cells. P. anisum fractions (PAF1, PAF2 and PAF3) were mainly composed of neutral sugars (84.0-98.2%) and uronic acids (2.1-11.8%) with weight average molecular weight (M_w) ranging from 186.6 to 5474.5 × 10³ g/mol. Polysaccharides induced a significant inflammatory response in RAW264.7 murine macrophage cells releasing nitric oxide and expressing TNF-α, IL-1β, IL-6 and IL-10 cytokines. The induction of NK-92 natural killer cells resulted in TNF-α and IFN-γ production and activation of GrB/perforin-, NKG2D- and FasL-mediated cytotoxicity. Polysaccharides triggered the phosphorylation of NF-κB, ERK, JNK and p38 proteins in RAW264.7 and NK-92 cells indicating the involvement of NF-κB and MAPKs signaling pathways. The most active polysaccharide was a galactoarabinan with complex structure.

Immunological Activity and Gut Microbiota Modulation of Pectin from Kiwano (Cucumis metuliferus) Peels

For developing the recycling of fruit by-products from kiwano, a polysaccharide was extracted from kiwano (Cucumis metuliferus) peels, namely Cucumis metuliferus peels polysaccharide (CMPP), with the aim of investigating the potential beneficial effects. The composition of polysaccharides was analyzed by chemical methods. RAW264.7 macrophages cells and the microbiota dynamics simulator (BFBL gut model) were used for in vitro study. The result showed that CMPP mainly consists of glucuronic acid, arabinose, galactose and rhamnose. By intervening with RAW264.7 cells, CMPP promoted cell proliferation and showed immune-enhancing activity, which significantly (p < 0.05) induced the release of nitric oxide (NO), tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) at a concentration of 50 μg/mL. In addition, CMPP had an impact on the composition of the gut bacteria, increasing the growth of Akkermansia, Bacteroides, Bifidobacterium, Feacalibacterium, and Roseburia. During the intake period, acetic, butyric and propionic acids were all increased, especially (p < 0.05) in the descending colon. Moreover, a decrease in ammonia concentration (10.17 ± 0.50 mM in the ascending colon, 13.21 ± 1.54 mM in the transverse colon and 13.62 ± 0.45 mM in the descending colon, respectively) was observed. In summary, CMPP can be considered as a pectin, showed immunological activity and function of gut microbiota modulation. This study could be the scientific basis of developing kiwano peels as beneficial to human health.

Immunomodulatory activity of Senegalia macrostachya (Reichenb. ex DC.) Kyal. & Boatwr seed polysaccharide fraction through the activation of the MAPK signaling pathway in RAW264.7 macrophages

Senegalia macrostachya (Reichenb. ex DC.) Kyal. & Boatwr seed (SMS) is a wild legume used as food and medicine in many African countries. In the current study, a novel polysaccharide (SMSP2) was extracted from SMS using hot water and purified with DEAE-52 cellulose. Its structure was characterized, and the immunomodulatory activity and possible molecular mechanism in murine macrophage RAW264.7 were explored. The results revealed that SMSP2 was a uronic acid-rich polysaccharide (51.6%, w/w) with a molecular weight of 52.07 kDa. The neutral sugars were mainly arabinose, xylose, mannose, and galactose at a molar ratio of 1.00 : 0.84 : 0.90 : 0.07. Interestingly, SMSP2 treatment markedly promoted macrophage proliferation and phagocytosis and induced the expression of inflammatory mediators, such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-10. SMSP2-induced macrophage stimulation occurs through the activation of the mitogen-activated protein kinase (MAPK) signaling pathway. Moreover, macrophage surface complement receptor 3 (CR3) might play an important role in SMSP2-induced macrophage activation. This study revealed that SMSP2 is a potent immunomodulator, which could be used as a functional food and a pharmaceutical adjuvant in treating immune-compromising diseases.

Structure–immunomodulatory activity relationships of dietary polysaccharides

Polysaccharides are usually composed of more than ten monosaccharide units, which are connected by linear or branched glycosidic bonds. The immunomodulatory effect of natural polysaccharides is one of the most important bioactive function. In this review, molecular weight, monosaccharide (including galactose, mannose, rhamnogalacturonan-I arabinogalactan and uronic acid), functional groups (namely sulfate, selenium, and acetyl groups), types of glycoside bond connection (including β-1,3-D-glucosyl, α-1,4-D-glucosyl, β-1,4-D-glucosyl, α-1,6-D-glucosyl, β-1,4-D-mannosyl, and β-1,4-D-Xylopyranosyl), conformation and the branching degrees are systematically identified as their contribution to the immunostimulatory activity of polysaccharides. At present, studies on the structure-activity relationships of polysaccharides are limited due to their low purity and high heterogeneity. However, it is an important step in providing useful guidance for dietary supplements with polysaccharides. The chemical structures and the process of immune responses induced are necessary to be discussed. Polysaccharides may bind with the cell surface receptors to modulate immune responses. This review mainly discusses the structure-activity relationship of dietary polysaccharides.

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Structure - activity relationships of polysaccharides with immune-enhancing effect are proposed.

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Polysaccharides with the higher molecular weight are helpful to improve immunity.

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Higer galactose, mannose, rhamnogalacturonan-I, arabinogalacta,n and uronic acid contents have immunoregulation.

Ongoing and potential novel trends of pomegranate fruit peel; a comprehensive review of its health benefits and future perspectives as nutraceutical

Pomegranate is an ancient shrub, globally distributed nowadays. It has been used in the middle east as a medicinal food and traditional medicine for thousands of years. Pomegranate peel (PP) constitutes about 50% of the total fruit, however, it has been previously regarded as a waste. Recent research points to PP as a rich source of phenolics (e.g., ellagitannins, flavonoids, and anthocyanins), polysaccharides, in addition to its biotransformed metabolites viz. urolithins making it a valuable waste with promising pharmacological actions. Compared to the pulp and the juice, PP exhibited stronger antioxidant and antimicrobial activities. Besides, it inhibited inflammation in several conditions, including colitis, arthritis, hepatitis, contact dermatitis, and lung inflammation. Moreover, it displayed anti-osteoporosis, anti-hyperglycemic, antidiabetic, antihypertensive, vasculoprotective, hepatoprotective, neuroprotective, and immunomodulatory effects. Additionally, it was effective as a prebiotic and in obesity control, besides it promoted wound healing. Furthermore, PP demonstrated anticancer effects against different cancer types, for example, colon, liver, thyroid, uterine, breast, bladder, prostate, leukemia, and osteosarcoma. Despite PP safety, it may interfere with the metabolism of other drugs because it inhibits cytochromes (CYP) changing their bioavailability, effectiveness, and toxicity. PP biowaste valorization not only avoids against its environmental and economic burden but can also provide a promising platform to produce novel or improved nutraceuticals. This study provides a comprehensive overview of PP biological activities with the reported action mechanisms related to its phytochemicals and further biotransformed metabolites inside the body. Future research prospects to unravel the merits of such waste and optimize its use are discussed. PRACTICAL APPLICATION: Pomegranate is widely distributed throughout the world. Although its peel was previously considered a waste, recent research regards it as a rich source of bioactive compounds with promising biological activities. Its recycling not only overcomes the bio-waste problems, but also provides a source of valuable compounds with several health benefits. In recent years, PP has been demonstrated to exhibit excellent pharmacological bioactivities, for example, antioxidant, anti-inflammatory, antimicrobial, antiosteoporosis, antihyperlipidemic, and anticancer activities. Its health-promoting power is mostly attributed to the phenolic and polysaccharide content, in addition to its amazing biotransformed metabolites. The underlying action mechanisms of such pharmacological activities are discussed and related to its chemical content. This review presents the latest research progress on the role of PP in the prevention and treatment of various chronic diseases, and its protective health effects for future research to be used in nutraceuticals.

Beneficial Effects of Polysaccharides on the Epithelial Barrier Function in Intestinal Mucositis

Intestinal mucositis is a clinically relevant side effect of anticancer therapies. It is experienced by 60–100% of patients undergoing treatment with high doses of chemotherapy, radiation therapy, and bone marrow transplantation. Intestinal mucositis can manifest as pain, weight loss, inflammation, diarrhea, rectal bleeding, and infection; affecting normal nutritional intake and intestinal function. It often impacts adherence to anticancer therapy as it frequently limits patient’s ability to tolerate treatment, causing schedule delays, interruptions, or premature discontinuation. In some cases, local and systemic secondary infections are observed, increasing the costs toward medical care and hospitalization. Several strategies for managing mucositis are available which do not always halt this condition. In this context, new therapeutic strategies are under investigation to prevent or treat intestinal mucositis. Polysaccharides from natural resources have recently become promising molecules against intestinal damage due to their ability to promote mucosal healing and their anti-inflammatory actions. These effects are associated with the protection of intestinal mucosa and regulation of microbiota and immune system. This review aims to discuss the recent advances of polysaccharides from natural resources as potential therapies for intestinal mucositis. The source, species, doses, treatment schedules, and mechanisms of action of polysaccharides will be discussed in detail.

Structural characterization of novel arabinoxylan and galactoarabinan from citron with potential antitumor and immunostimulatory activities

This study aimed to extract polysaccharides from citron and analyze their structures and potential bioactivities. Two novel polysaccharides CM-1 and CM-2 were purified from citron by DEAE-Sepharose Fast Flow and Sephadex G-100 column chromatography. Monosaccharide composition, linkage and NMR data were used to infer their sugar chains composition. The anti-breast cancer cells and immunoregulatory activities of CM-1 and CM-2 were investigated. Results indicated that CM-1 (Mw = 21,520 Da), composed of arabinose, xylose, mannose and glucose in a molar ratio of 10.78:11.53:1.00:1.70, was arabinoxylan (AX) with (1 → 4)-linked β-d-Xylp skeleton monosubstituted with α-l-Araf units at O-3 position. While CM-2 (Mw = 22,303 Da), composed of arabinose, mannose, glucose and galactose in a molar ratio of 25.46:1.45:1.00:6.57, was galactoarabinan (GA) with (1 → 5)-linked α-l-Araf backbone substituted by β-d-Galp units at O-2 and/or O-3 positions. Both polysaccharides exhibited potential inhibiting cancer and immunostimulatory activities in vitro, especially CM-1. These results provide a basis for further research on citron polysaccharides.

Pomegranate Peel as Suitable Source of High-Added Value Bioactives: Tailored Functionalized Meat Products

In the last few years, the consumer's concern with the relationship between health and diet has led to the search of foods with functional properties beyond the nutritional. In this framework, the consumption of pomegranate has increased due to their sensorial attributes and remarkable amounts of bioactive compounds, which generate, at the same time, huge amounts of by-products. A search in the Scopus database for the last 10 years has revealed the rising interest in pomegranate peel (PP), the main residue from this fruit. The meat industry is a food sector that has had to search for new alternatives to substitute the use of synthetic preservatives by new natural additives, to extend the self-life and keep the quality attributes of their processed products. This review sets out the main bioactivities of PP extracts, and their incorporation in meat products is elaborated. PP is a good source of bioactive compounds, including phenolic acids, flavonoids and hydrolyzable tannins, which have beneficial health effects. It can be concluded that the reformulation of meat products with PP extracts is a suitable strategy for enhancing their technological characteristics, in addition to conferring functional properties that make them healthier and potentially more acceptable for the consumer.

Structural characterization of polysaccharides with potential antioxidant and immunomodulatory activities from Chinese water chestnut peels

Chinese water chestnut peels are a kind of vegetable processing waste containing many active components such as polysaccharides, the structure of which remains unknown. To elucidate the structure of polysaccharides from Chinese water chestnut peels, two polysaccharides named WVP-1 and WVP-2 were isolated. WVP-1 (3.16 kDa) consisted of mannose (1.75 %), glucose (84.69 %), galactose (6.32 %), and arabinose (7.24 %), while WVP-2 (56.97 kDa) was composed of mannose (3.18 %), rhamnose (1.52 %), glucuronic acid (1.42 %), galacturonic acid (4.83 %), glucose (11.51 %), galactose (36.02 %), and arabinose (41.53 %). Linkage and NMR data indicated that WVP-1 was composed mainly of →4)-α-d-Glcp(1→ and a certain proportion of →3)-β-d-Glcp-(1→, including linear and branched polysaccharides simultaneously. WVP-2 was a pectin-like polysaccharide with →4)-α-d-GalpA6Me-(1→ units and the branch points of →3,4)-α-l-Arap-(1→, →3,6)-β-d-Galp-(1→. WVP-2 exhibited stronger potential antioxidant and immunomodulatory activities than WVP-1 in vitro. These results provide a foundation for the further study of polysaccharides from Chinese water chestnut peels.

Characterization of Arils Juice and Peel Decoction of Fifteen Varieties of Punica granatum L.: A Focus on Anthocyanins, Ellagitannins and Polysaccharides

Pomegranate is receiving renewed commercial and scientific interest, therefore a deeper knowledge of the chemical composition of the fruits of less studied varieties is required. In this work, juices from arils and decoctions from mesocarp plus exocarp were prepared from fifteen varieties. Samples were submitted to High Performance Liquid Chromatography-Diode Array Detector-Mass Spectrometry, spectrophotometric and colorimetric CIEL*a*b* analyses. Antioxidant, antiradical and metal chelating properties, inhibitory activity against tyrosinase and α-amylase enzymes were also evaluated. All varieties presented the same main phenols; anthocyanins and ellagitannins were widely variable among varieties, with the richest anthocyanin content in the juices from the Wonderful and Soft Seed Maule varieties (approx. 660 mg/L) and the highest ellagitannin content in the peel of the Black variety (approx. 133 mg/g dry matter). A good correlation was shown between the colour hue and the delphinidin/cyanidin ratio in juices (R2 = 0.885). Total polysaccharide yield ranged from 3% to 12% of the peels' dry weight, with the highest content in the Black variety. Decoctions (24.44-118.50 mg KAE/g) showed better in vitro antioxidant properties and higher inhibitory capacity against tyrosinase than juices (not active-16.56 mg KAE/g); the inhibitory capacity against α-amylase was similar and quite potent for juices and decoctions. Knowledge about the chemical composition of different pomegranate varieties will allow for a more aware use of the different parts of the fruit.

Food Applications and Potential Health Benefits of Pomegranate and its Derivatives

Pomegranate (Punica granatum L.) is an ancient fruit that is particularly cultivated in west Asia, though it is also cultivated in the Mediterranean region and other parts of the world. Since ancient years, its consumption has been associated with numerous health benefits. In recent years, several in vitro and in vivo studies have revealed its beneficial physiological activities, especially its antioxidative, antimicrobial and anti-inflammatory properties. Furthermore, human-based studies have shown promising results and have indicated pomegranate potential as a protective agent of several diseases. Following that trend and the food industry's demand for antioxidants and antimicrobials from natural sources, the application of pomegranate and its extracts (mainly as antioxidants and antimicrobials), has been studied extensively in different types of food products with satisfactory results. This review aims to present all the recent studies and trends in the applications of pomegranate in the food industry and how these trends have affected product's physicochemical characteristics and shelf-life. In addition, recent in vitro and in vivo studies are presented in order to reveal pomegranate's potential in the treatment of several diseases.

Primary Metabolites, Anthocyanins, and Hydrolyzable Tannins in the Pomegranate Fruit

Pomegranate (Punica granatum L.) is an important and interesting fruit tree that is cultivated in many parts of the world. In recent years, along with the increase in its cultivation and consumption there has been a dramatic increase in the scientific interest in its biology, methods of cultivation, adaptation to environmental cues and its health-promoting properties. Quite a large proportion of the various metabolites produced in the pomegranate were determined and their content in the bark, roots, leaves, and fruit was reported. Many reviews on polyphenolic compound content, antioxidant activity and health-promoting compounds were published recently. However, only very few recent reports were dedicated to primary metabolites, despite the fact that much work was done on organic acids, sugars, proteins, lipids, and amino acids of the pomegranate fruit. In this review, a special effort was made to present these recent studies and the review is devoted to primary metabolites. The reported data show high variation in the content of primary metabolites within the pomegranate fruit; therefore the data is presented (whenever possible) according to fruit tissues (peel, arils, and seeds), developmental stages of the fruit, environmental and climatic conditions, and genetic background. Most of the data on pomegranate is based on metabolic content and contains no genetic or molecular analysis except for work done on anthocyanins and hydrolyzable tannins. In those cases, gene assignment and genetic control studies were pointed out in the review. The recent publication of the genome sequences from several pomegranate varieties and transcriptomic data from fruits, flowers, and leaves is expected to facilitate the understanding of genetic control of metabolites in pomegranate.