The bioactivity of modified pectin fragments

Novel role of homogalacturonan region of pectin in disrupting the interaction between fibronectin and integrin β1

Pectin interacts with fibronectin (FN), a modular protein in the extracellular matrix. This interaction is significant as FN plays a pivotal role by binding to the receptor integrin α5β1. However, the molecular mechanism underlying the pectin-FN interaction and its impact on integrin binding remains unknown. In this study, water-soluble pectins (WSPs) were extracted from three different pectin sources and subsequently characterized. These included Citrus WSP, which primarily comprises the homogalacturonan region, and Kaki and Yuzu WSPs, both of which are rich in rhamnogalacturonan regions. We investigated the molecular interactions between these WSPs and two FN fragments, Anastellin and RetroNectin, using surface plasmon resonance analysis. Citrus WSP exhibited a notable binding affinity to FN, with a dissociation constant (KD) of approximately 10-7 M. In contrast, Kaki and Yuzu WSPs displayed comparatively weaker or negligible binding affinities. The binding reactivity of Citrus WSP with FN was notably diminished following the enzymatic removal of its methyl-ester groups. Additionally, Citrus WSP disrupted the binding of integrin β1 to RetroNectin without altering the affinity, despite its minimal direct binding to integrin itself. This study furthers our understanding of the intricate pectin-FN interaction and sheds light on their potential physiological relevance and impact on cellular responses.

Comparative analysis of pectin and prebiotics on human microbiota modulation in early life stages and adults

The gut microbiota is essential in human health, influencing various physiological processes ranging from digestion and metabolism to immune function and mental health. Dietary fiber pectins and prebiotics have emerged as key modulators of gut microbiota composition and function, offering potential therapeutic implications for promoting gut health and preventing intestinal inflammatory diseases. In this review, we explore the modulation of gut microbiota by dietary fiber pectins and prebiotics in infants and adults. We begin with an overview of the gut microbiota composition and function in different age groups, highlighting the factors in shaping microbial communities in both age groups, especially the effect of diet. We then delve into the impact of dietary fiber pectins and prebiotics on gut microbiota composition and function, examining their effects on digestive health, intestinal barrier integrity, immune function, metabolic health, and mental health across different life stages. We further compare how aging affects the gut function and immune system, and we discuss the main health outcomes associated with dietary fiber intake and prebiotics, including the impact on digestive health, improvement in immune function, improvement in cholesterol and glucose metabolism, weight management, mental health, and prevention of diseases. Finally, we highlight the challenges and future directions for research. By advancing the understanding of gut microbiota dynamics and translating scientific insights into clinical practice, it could harness the full potential of dietary fiber pectins and prebiotics to optimize gut health, improve overall well-being across the lifespan, and increase longevity.

Pectin as a biofunctional food: comprehensive overview of its therapeutic effects and antidiabetic-associated mechanisms

Pectin is a complex polysaccharide found in a variety of fruits and vegetables. It has been shown to have potential antidiabetic activity along with other biological activities, including cholesterol-lowering properties, antioxidant activity, anti-inflammatory and immune-modulatory effects, augmented healing of diabetic foot ulcers and other health benefits. There are several pectin-associated antidiabetic mechanisms, such as the regulation of glucose metabolism, reduction of oxidative stress, increased insulin sensitivity, appetite suppression and modulation of the gut microbiome. Studies have shown that pectin supplementation has antidiabetic effects in different animal models and in vitro. In human studies, pectin has been found to have a positive effect on blood glucose control, particularly in individuals with type 2 diabetes. Pectin also shows synergistic effects by enhancing the potency and efficacy of antidiabetic drugs when taken together. In conclusion, pectin has the potential to be an effective antidiabetic agent. However, further research is needed to fully understand its detailed molecular mechanisms in various animal models, functional food formulations and safety profiles for the treatment and management of diabetes and associated complications in humans. The current study was carried out to provide the critical approach towards therapeutical potential, anti-diabetic potential and underlying molecular mechanisms on the basis of existing knowledge.

Anticancer Mechanism of Astragalus Polysaccharide and Its Application in Cancer Immunotherapy

Astragalus polysaccharide (APS) derived from A. membranaceus plays a crucial role in traditional Chinese medicine. These polysaccharides have shown antitumor effects and are considered safe. Thus, they have become increasingly important in cancer immunotherapy. APS can limit the spread of cancer by influencing immune cells, promoting cell death, triggering cancer cell autophagy, and impacting the tumor microenvironment. When used in combination with other therapies, APS can enhance treatment outcomes and reduce toxicity and side effects. APS combined with immune checkpoint inhibitors, relay cellular immunotherapy, and cancer vaccines have broadened the application of cancer immunotherapy and enhanced treatment effectiveness. By summarizing the research on APS in cancer immunotherapy over the past two decades, this review elaborates on the anticancer mechanism of APS and its use in cancer immunotherapy and clinical trials. Considering the multiple roles of APS, this review emphasizes the importance of using APS as an adjunct to cancer immunotherapy and compares other polysaccharides with APS. This discussion provides insights into the specific mechanism of action of APS, reveals the molecular targets of APS for developing effective clinical strategies, and highlights the wide application of APS in clinical cancer therapy in the future.

Ripe papaya pectins inhibit the proliferation of colon cancer spheroids and the formation of chemically induced aberrant crypts in rats colons

Pectins are a class of soluble polysaccharides that can have anticancer properties through several mechanisms. This study aimed to characterize the molecular structure of water-soluble fractions (WSF) derived from ripe and unripe papayas and assess their biological effects in two models: the 3D colon cancer spheroids to measure cell viability and cytotoxicity, and the in vivo model to investigate the inhibition of preneoplastic lesions in rats. WSF yield was slightly higher in ripe papaya, and both samples mainly consisted of pectin. Both pectins inhibited the growth of colon cancer HT29 and HCT116 spheroids. Unripe pectin disturbed HT29/NIH3T3 spheroid formation, decreased HCT116 spheroid viability, and increased spheroid cytotoxicity. Ripe pectin had a more substantial effect on the reduction of spheroid viability for HT29 spheroids. Furthermore, in vivo experiments on a rat model revealed a decrease in aberrant crypt foci (ACF) formation for both pectins and increased apoptosis in colonocytes for ripe papaya pectins. The results suggest potential anticancer properties of papaya pectin, with ripe pectin showing a higher potency.

Insights into the impact of modification methods on the structural characteristics and health functions of pectin: A comprehensive review

Pectin is a complex polysaccharide that is widely present in plant cells and has multiple physiological functions. However, most pectin exists in the form of protopectin, which has a large molecular weight and cannot be fully absorbed and utilized in the human gut to exert its effects. The significant differences in the structure of different sources of pectin also limited their application in the food and medical fields. In order to achieve greater development and utilization of pectin functions, this paper reviewed several commonly used methods for pectin modification from physical, chemical, and biological perspectives, and elaborated on the relationship between these modification methods and the structure and functional properties of pectin. At the same time, the functional characteristics of modified pectin and its application in medical health, such as regulating intestinal health, anticancer, anti-inflammatory, and drug transport, were reviewed, so as to provide a theoretical basis for targeted modification of pectin and the development of new modified pectin products.

Dietary fiber pectin: challenges and potential anti-inflammatory benefits for preterms and newborns

Pectins, a class of dietary fibers abundant in vegetables and fruits, have drawn considerable interest due to their potential anti-inflammatory properties. Numerous studies have indicated that incorporating pectins into infant formula could be a safe strategy for alleviating infant regurgitation and diarrhea. Moreover, pectins have been shown to modulate cytokine production, macrophage activity, and NF-kB expression, all contributing to their anti-inflammatory effects. Despite this promising evidence, the exact mechanisms through which pectins exert these functions and how their structural characteristics influence these processes remain largely unexplored. This knowledge is particularly significant in the context of gut inflammation in developing preterm babies, a critical aspect of necrotizing enterocolitis (NEC), and in children and adults dealing with inflammatory bowel disease (IBD). Our mini review aims to provide an up-to-date compilation of relevant research on the effects of pectin on gut immune responses, specifically focusing on preterms and newborns. By shedding light on the underlying mechanisms and implications of pectin-mediated anti-inflammatory properties, this review seeks to advance our knowledge in this area and pave the way for future research and potential therapeutic interventions.

Modification methods, biological activities and applications of pectin: A review

Pectin is a complex and functionally rich natural plant polysaccharide that is widely used in food, medical, and cosmetic industries. It can be modified to improve its properties and expand its applications. Modification methods for natural pectin can be divided into physical, chemical, enzymatic, and compound methods. Different modification methods can result in modified pectins (MPs) exhibiting different physicochemical properties and biological activities. The objectives of this paper were to review the various pectin modification methods explored over the last decade, compare their differences, summarize the impact of different modification methods on the biological activity and physicochemical properties of pectin, and describe the applications of MPs in food and pharmaceutical fields. Finally, suggestions and perspectives for the development of MPs are discussed. This review offers a theoretical reference for the rational and efficient processing of pectin and the expansion of its applications.

A novel Stauntonia leucantha fruits arabinogalactan: and structural characterization

Polysaccharides were the key ingredients of many herbal medicines, and were responsible for multiple pharmacological activities. In this study, a novel polysaccharide fraction, named SLP-2, was isolated from Stauntonia leucantha fruits, and purified by DEAE-52 and Sephadex G-100 column chromatography. Furthermore, SLP-2 was identified by congo red, methylation, partial acid hydrolysis and NMR. The results indicated that the backbone of SLP-2 was composed of →4)-β-D-Galp-(1 → 4)-β-D-Galp-(1→ substituted at C-6 with 1,5-linked arabinan. SLP-2 had good anti-oxidation ability in vitro. Surprisingly, we found that reduction of carboxyl groups and methylation of hydroxyl groups enhanced the ability to scavenge 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and inhibit lipid peroxidation, and weakened the activity to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reduce ferric iron.

The Preparation and Potential Bioactivities of Modified Pectins: A Review

Pectins are complex polysaccharides that are widely found in plant cells and have a variety of bioactivities. However, the high molecular weights (M_w) and complex structures of natural pectins mean that they are difficult for organisms to absorb and utilize, limiting their beneficial effects. The modification of pectins is considered to be an effective method for improving the structural characteristics and promoting the bioactivities of pectins, and even adding new bioactivities to natural pectins. This article reviews the modification methods, including chemical, physical, and enzymatic methods, for natural pectins from the perspective of their basic information, influencing factors, and product identification. Furthermore, the changes caused by modifications to the bioactivities of pectins are elucidated, including their anti-coagulant, anti-oxidant, anti-tumor, immunomodulatory, anti-inflammatory, hypoglycemic, and anti-bacterial activities and the ability to regulate the intestinal environment. Finally, suggestions and perspectives regarding the development of pectin modification are provided.

Advances and Innovations of 3D Bioprinting Skin

Three-dimensional (3D) bioprinted skin equivalents are highlighted as the new gold standard for alternative models to animal testing, as well as full-thickness wound healing. In this review, we focus on the advances and innovations of 3D bioprinting skin for skin regeneration, within the last five years. After a brief introduction to skin anatomy, 3D bioprinting methods and the remarkable features of recent studies are classified as advances in materials, structures, and functions. We will discuss several ways to improve the clinical potential of 3D bioprinted skin, with state-of-the-art printing technology and novel biomaterials. After the breakthrough in the bottleneck of the current studies, highly developed skin can be fabricated, comprising stratified epidermis, dermis, and hypodermis with blood vessels, nerves, muscles, and skin appendages. We hope that this review will be priming water for future research and clinical applications, that will guide us to break new ground for the next generation of skin regeneration.

Pectin: A Bioactive Food Polysaccharide with Cancer Preventive Potential

Pectin is an acidic heteropolysaccharide found in the cell walls and the primary and middle lamella of land plants. To be authorized as a food additive, industrial pectins must meet strict guidelines set forth by the Food and Agricultural Organization and must contain at least 65% polygalacturonic acid to achieve the E440 level. Fruit pectin derived from oranges or apples is commonly used in the food industry to gel or thicken foods and to stabilize acid-based milk beverages. It is a naturally occurring component and can be ingested by dietary consumption of fruit and vegetables. Preventing long-term chronic diseases like diabetes and heart disease is an important role of dietary carbohydrates. Colon and breast cancer are among the diseases for which data suggest that modified pectin (MP), specifically modified citrus pectin (MCP), has beneficial effects on the development and spread of malignancies, in addition to its benefits as a soluble dietary fiber. Cellular and animal studies and human clinical trials have provided corroborating data. Although pectin has many diverse functional qualities, this review focuses on various modifications used to develop MP and its benefits for cancer prevention, bioavailability, clinical trials, and toxicity studies. This review concludes that pectin has anti-cancer characteristics that have been found to inhibit tumor development and proliferation in a wide variety of cancer cells. Nevertheless, further clinical and basic research is required to confirm the chemopreventive or therapeutic role of specific dietary carbohydrate molecules.

Effects of pectins on colorectal cancer: targeting hallmarks as a support for future clinical trials

The intake of dietary fibers has been associated with a reduction in the risk of colorectal cancer.

Recent advances in utilization of pectins in biomedical applications: a review focusing on molecular structure-directing health-promoting properties

The numerous health benefits of pectins justify their inclusion in human diets and biomedical products. This review provides an overview of pectin extraction and modification methods, their physico-chemical characteristics, health-promoting properties, and pharmaceutical/biomedical applications. Pectins, as readily available and versatile biomolecules, can be tailored to possess specific functionalities for food, pharmaceutical and biomedical applications, through judicious selection of appropriate extraction and modification technologies/processes based on green chemistry principles. Pectin's structural and physicochemical characteristics dictate their effects on digestion and bioavailability of nutrients, as well as health-promoting properties including anticancer, immunomodulatory, anti-inflammatory, intestinal microflora-regulating, immune barrier-strengthening, hypercholesterolemia-/arteriosclerosis-preventing, anti-diabetic, anti-obesity, antitussive, analgesic, anticoagulant, and wound healing effects. HG, RG-I, RG-II, molecular weight, side chain pattern, and degrees of methylation, acetylation, amidation and branching are critical structural elements responsible for optimizing these health benefits. The physicochemical characteristics, health functionalities, biocompatibility and biodegradability of pectins enable the construction of pectin-based composites with distinct properties for targeted applications in bioactive/drug delivery, edible films/coatings, nano-/micro-encapsulation, wound dressings and biological tissue engineering. Achieving beneficial synergies among the green extraction and modification processes during pectin production, and between pectin and other composite components in biomedical products, should be key foci for future research.

Structural and Biological Properties of Water Soluble Polysaccharides from Lotus Leaves: Effects of Drying Techniques

In the present study, the influence of five drying techniques on the structural and biological properties of polysaccharides from lotus leaves (LLPs) was investigated. Results revealed that the yields, contents of basic chemical components, molecular weights, and molar ratios of compositional monosaccharides of LLPs varied by different drying technologies. Low molecular weight distributions were observed in polysaccharides obtained from lotus leaves by hot air drying (LLP-H), microwave drying (LLP-M), and radio frequency drying (LLP-RF), respectively. The high contents of bound polyphenolics were measured in LLP-H and LLP-M, as well as polysaccharides obtained from lotus leaves by vacuum drying (LLP-V). Furthermore, both Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectra of LLPs were similar, indicating that drying technologies did not change their basic chemical structures. Besides, all LLPs exhibited obvious biological properties, including in vitro antioxidant capacities, antiglycation activities, and inhibitory effects on α-glucosidase. Indeed, LLP-H exhibited higher 2,2-azidobisphenol (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability (IC₅₀ values, LLP-H, 0.176 ± 0.004 mg/mL; vitamin C, 0.043 ± 0.002 mg/mL) and 2,2-diphenyl-1-(2,4,6-trinitrate phenyl) hydrazine radical scavenging ability (IC₅₀ values, LLP-H, 0.241 ± 0.007 mg/mL; butylated hydroxytoluene, 0.366 ± 0.010 mg/mL) than others, and LLP-M exerted stronger antiglycation (IC₅₀ values, LLP-M, 1.023 ± 0.053 mg/mL; aminoguanidine, 1.744 ± 0.080 mg/mL) and inhibitory effects on α-glucosidase (IC₅₀ values, LLP-M, 1.90 ± 0.02 μg/mL; acarbose, 724.98 ± 16.93 μg/mL) than others. These findings indicate that both hot air drying and microwave drying can be potential drying techniques for the pre-processing of lotus leaves for industrial applications.

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.

Apple pomaces derived from mono-varietal Asturian ciders production are potential source of pectins with appealing functional properties

Comprehensive chemical characterization of nine mono-varietal apple pomaces obtained from the production of ciders with PDO is described. They were rich in essential minerals, fibers (35-52.9 %), and polyphenols. High levels in GalA (11.8-21.6 %), revealed the suitability of these apple pomaces as efficient sources of pectins. Extracted pectins showed high variability in monomer composition, with degrees of methylesterification, strongly associated with pectins functional properties, ranging from 58 to 88 %. For a subset of apple pomace varieties, pectin extraction was accomplished by conventional acid heat treatment or ultrasound. Despite ultrasound-assisted extraction did not improve pectin yield, it minimized levels of "non-pectin" components as revealed by the low content of Glc/Man, leading to the obtainment of high-purity pectin. Our work highlights the key role played by the selection of the apple variety to streamline the potential food applications (gelling/thickening agents or prebiotics) of the extracted pectins that largely depend on their structural features.

In vitro digestion of polysaccharides: InfoGest protocol and use of small intestinal extract from rat

Starch, dextran, pectin and modified citrus pectin were subjected to intestinal digestion following InfoGest protocol and a rat small intestine extract (RSIE) treatment. Gastric stage did not show any modification in the structure of the carbohydrates, except for modified pectin. Regarding intestinal phases, starch was hydrolyzed by different ways, resulting in a complementary behavior between InfoGest and RSIE. Contrarily, digestion of dextran was only observed using RSIE. Similar situation occurred in the case of pectins with RSIE, obtaining a partial hydrolysis, especially in the modified citrus pectin. However, citrus pectin was the less prone to hydrolysis by enzymes. The results demonstrated that InfoGest method underestimates the significance of the carbohydrates hydrolysis at the small intestine, thus indicating that RSIE is a very reliable and useful method for a more realistic study of polysaccharides digestion.

Behaviour of citrus pectin and modified citrus pectin in an azoxymethane/dextran sodium sulfate (AOM/DSS)-induced rat colorectal carcinogenesis model

Large intestine cancer is one of the most relevant chronic diseases taking place at present. Despite therapies have evolved very positively, this pathology is still under deep investigation. One of the recent approaches is the prevention by natural compounds such as pectin. In this paper, we have assessed the impact of citrus pectin and modified citrus pectin on colorectal cancer in rats (Rattus norvegicus F344) to which azoxymethane and DSS were supplied. The lowest intake of food and body weight were detected in animals fed with citrus pectin, together with an increase in the caecum weight, probably due to the viscosity, water retention capacity and bulking properties of pectin. The most striking feature was that, neither citrus pectin nor modified citrus pectin gave rise to a tumorigenesis prevention. Moreover, in both, more than 50% of rats with cancer died, probably ascribed to a severe dysbiosis state in the gut, as shown by the metabolism and metagenomics studies carried out. This was related to a decrease of pH in caecum lumen and increase in acetate and lactic acid levels together with the absence of propionic and butyric acids. A relevant increase in Proteobacteria (Enterobacteriaceae) were thought to be one of the reasons for enteric infection that could have provoked the death of rats and the lack of cancer prevention. However, a reduction of blood glucose and triacylglycerides level and an increase of Bifidobacterium and Lactobacillaceae were found in animals that intake pectin, as compared to universal and modified citrus pectin feeding.

Polysaccharides from dandelion (Taraxacum mongolicum) leaves: Insights into innovative drying techniques on their structural characteristics and biological activities

The aim of this study was to well understand the impacts of innovative drying techniques (radio frequency drying and microwave drying) and traditional drying techniques (vacuum drying, freezing drying, and hot air drying) on the structural characteristics and bioactivities of polysaccharides from dandelion leaves (DLPs). Five different DLPs were obtained from dandelion leaves dried by abovementioned drying techniques. Results showed that the structural characteristics and bioactivities of DLPs varied with different drying techniques. The molecular weights, apparent viscosities, molar ratios of constituent monosaccharide, contents of uronic acids, and contents of bonded polyphenolics in DLPs obtained by different drying techniques had noticeable variations, while the types of constituent monosaccharides and the major glycosidic linkages in DLPs were similar. In addition, results showed that DLPs, especially DLP-RF obtained by the radio frequency drying, exhibited remarkable antioxidant activities (ABTS, DPPH, and NO radical scavenging activities), excellent in vitro antiglycation activity, and obvious in vitro inhibitory activity on α-glucosidase. Results from this study suggest that the radio frequency drying can be used as a potential drying technique before extracting DLPs for applications in the functional food and medicine industries.

Modified citrus pectins by UV/H2O2 oxidation at acidic and basic conditions: Structures and in vitro anti-inflammatory, anti-proliferative activities

Two modified citrus pectins, MCP4 and MCP10, were prepared by UV/H₂O₂ treatment at pH 4 and pH 10, respectively, and their structures were characterized. MCP10 had a rhamnogalacturonan-I (RG-I) enriched backbone with a high degree of branching (DB ∼61 %) and a low methoxylation degree (24 %). MCP4 had a homogalacturonan enriched backbone with a high degree (46 %) of methoxylation and a low DB (∼41 %) of RG-I branches. MCP10 exhibited a higher anti-inflammatory activity than MCP4 in suppressing the NF-κB expression and the production of pro-inflammatory factors TNF-α and IL-1β of THP-1 cells stimulated by lipopolysaccharide. MCP10 also showed a stronger inhibitory effect on Caco-2 cell proliferation. The stronger bioactivities of MCP10 may be attributable to the abundant branches and the proper length of terminal galactan residues attached to the RG-I domain.

Transport, metabolism and remedial potential of functional food extracts (FFEs) in Caco-2 cells monolayer: A review

Caco-2, a human intestinal carcinoma cell line, has been used to test the absorption and transport mechanism of functional foods and drugs across the intestinal epithelium in order to study their antioxidant, anticancer and anti-inflammatory activities. Caco-2 cells represent the morphological and functional characteristics of small intestinal cells and capable of expressing brush borders, tight junctions, intestinal efflux and uptake transporters which regulate permeation of drugs and functional food extracts from intestinal lumen to systemic circulation. The integrity of the Caco-2 monolayer is controlled by establishing the TEER between 200 and 1000 O per cm². FFEs affect intestinal permeability by adjusting the tight junction proteins between the cells in order to maintain the epithelial barrier function. Because of the side effects of medicines, there is an increased interest in functional food extracts (FFEs) as drug substitutes. Functional foods undergo intricate transport processes and biotransformation after oral administration. Metabolism and transport studies of FFEs in Caco-2 cells are very important for determining their bioavailability. Functional foods and their constituents produce anti-proliferative and anti-cancer effects through apoptosis, cell cycle arrest and inhibition of various signal transduction pathways across Caco-2 cell lines. The current review has summarized the anti-inflammation, anticancer, antioxidant and cholesterol lowering potential of FFEs using Caco-2 cells through reducing local inflammatory signals, production of ROS and lipid accumulation. The transport, bioavailability, metabolism, mechanisms of actions, cellular pathways adopted by FFEs across Caco-2 cell lines are predominantly affected by their molecular weight, structures and physicochemical properties. These studies are beneficial for investigating the different mechanisms of action of FFEs in the human body.

Bioactives From Agri-Food Wastes: Present Insights and Future Challenges

Sustainable utilization of agri-food wastes and by-products for producing value-added products (for cosmetic, pharmaceutical or food industrial applications) provides an opportunity for earning additional income for the dependent industrial sector. Besides, effective valorisation of wastes/by-products can efficiently help in reducing environmental stress by decreasing unwarranted pollution. The major focus of this review is to provide comprehensive information on valorisation of agri-food wastes and by-products with focus laid on bioactive compounds and bioactivity. The review covers the bioactives identified from wastes and by-products of plants (fruits, exotic fruits, vegetables and seeds), animals (dairy and meat) and marine (fish, shellfish seaweeds) resources. Further, insights on the present status and future challenges of sustainably utilizing agri-food wastes/by-products for value addition will be highlighted.

Plant-derived saccharides and their inhibitory potential on metastasis associated cellular processes of pancreatic ductal adenocarcinoma cells

This study intends to investigate the inhibitory potential of different plant derived saccharides on cell migration and adhesion of pancreatic ductal adenocarcinoma (PDAC) cells to microvascular liver endothelium, particularly considering the role of transmembranous galectin-3. PDAC cell lines PancTu1 and Panc1 were characterized by considerable (transmembranous) galectin-3 (Gal3) expression. SiRNA mediated Gal3 knockdown as well as treatment with differentially processed pectins and arabinogalactan-proteins (AGPs) did not impact on cell migration of either PDAC cell line. In contrast, Gal3 knockdown reduced adhesion of PDAC cells to the liver endothelial cell line TMNK-1 being more pronounced in Panc1 cells. Similarly, plant derived substances did not impact cell adhesion of PancTu1 cells while partially hydrolyzed citrus pectin (MCP), pectinase-treated MCP (MCP_Pec) and partially hydrolized AGP (AGP_TFA) clearly diminished adhesive properties of Panc1 cells. MCP_Pec or AGP_TFA could not further intensify the adhesion reducing effect of galectin-3 knockdown, indicating that these plant derived polysaccharides are able to inhibit PDAC cell adhesion to liver endothelial cells in a galectin-3 dependent manner. Overall, these data suggest an inhibitory potential of plant derived processed saccharides which have undergone chemical modification in impairing PDAC cell adhesion to liver endothelium.

Migration and proliferation of cancer cells in culture are differentially affected by molecular size of modified citrus pectin

While chemically and thermally modified citrus pectin (MCP) has already been studied for health benefits, it is unknown how size-fractionated oligo- and polysaccharides differentially affect cancer cell behavior. We produced thermally MCP and fractionated it by molecular size to evaluate the effect these polymers have on cancer cells. MCP30/10 (between 30 and 10 kDa) had more esterified homogalacturonans (HG) and fewer rhamnogalacturonans (RG-I) than MCP and MCP30 (higher than 30 kDa), while MCP10/3 (between 10 and 3 kDa) showed higher amounts of type I arabinogalactans (AGI) and lower amounts of RG-I. MCP3 (smaller than 3 kDa) presented less esterified HG and the lowest amount of AGI and RG-I. Our data indicate that the enrichment of de-esterified HG oligomers and the AGI and RG-I depletions in MCP3, or the increase of AGI and loss of RGI in MCP30/10, enhance the anticancer behaviors by inhibiting migration, aggregation, and proliferation of cancer cells.

Pectin-rich extracts from olives inhibit proliferation of Caco-2 and THP-1 cells

Pectin-rich olive extracts from a by-product of olive oil production inhibits proliferation of Caco-2 and THP-1 cells, and hemagglutination by galectin-3. Activation of caspase-3 indicates induction of apoptosis.

Biological Activity and Pharmacological Application of Pectic Polysaccharides: A Review

Pectin is a polymer with a core of alternating α-1,4-linked d-galacturonic acid and α-1,2-l-rhamnose units, as well as a variety of neutral sugars such as arabinose, galactose, and lesser amounts of other sugars. Currently, native pectins have been compared to modified ones due to the development of natural medicines and health products. In this review, the results of a study of the bioactivity of pectic polysaccharides, including its various pharmacological applications, such as its immunoregulatory, anti-inflammatory, hypoglycemic, antibacterial, antioxidant and antitumor activities, have been summarized. The potential of pectins to contribute to the enhancement of drug delivery systems has been observed.

Ripening-induced chemical modifications of papaya pectin inhibit cancer cell proliferation

Papaya (Carica papaya L.) is a fleshy fruit with a rapid pulp softening during ripening. Ripening events are accompanied by gradual depolymerization of pectic polysaccharides, including homogalacturonans, rhamnogalacturonans, arabinogalactans, and their modified forms. During intermediate phases of papaya ripening, partial depolymerization of pectin to small size with decreased branching had enhanced pectin anti-cancer properties. These properties were lost with continued decomposition at later phases of ripening. Pectin extracted from intermediate phases of papaya ripening markedly decreased cell viability, induced necroptosis, and delayed culture wound closing in three types of immortalized cancer cell lines. The possible explanation for these observations is that papaya pectins extracted from the third day after harvesting have disrupted interaction between cancer cells and the extracellular matrix proteins, enhancing cell detachment and promoting apoptosis/necroptosis. The anticancer activity of papaya pectin is dependent on the presence and the branch of arabinogalactan type II (AGII) structure. These are first reports of AGII in papaya pulp and the first reports of an in vitro biological activity of papaya pectins that were modified by natural action of ripening-induced pectinolytic enzymes. Identification of the specific pectin branching structures presents a biological route to enhancing anti-cancer properties in papaya and other climacteric fruits.

Recovery of pectic hydrocolloids and phenolics from huanglongbing related dropped citrus fruit

BACKGROUND

Citrus pre-harvest fruit drop, caused by huanglongbing infection, has increased dramatically concomitant with declining tree health and crop harvest size. This loss of harvestable fruit is damaging to both growers and juice processors. Recovering and converting this fruit to alternative value added products would benefit the citrus industry. Therefore, we have explored the potential of using this fruit as a feedstock in our newly developed pilot scale continuous steam explosion process.

RESULTS

Whole fruits were converted to steam-exploded biomass using a continuous pilot scale process. The sugar composition of raw fruit and steam-exploded biomass was determined. Recovered pectic hydrocolloids and phenolic compounds were characterized. Pectic hydrocolloids comprised 78 g kg^-1 of the dry material in the dropped fruit. Following the steam explosion process almost all of the pectic hydrocolloids were recoverable with a water wash. They could be functionalized in situ or separated from the milieu. Additionally, approximately 40% of the polymethoxylated flavones, 10% of the flavanone glycosides, 85% of the limonoids and almost 100% of hydroxycinnamates were simultaneously recovered.

CONCLUSION

The continuous steam explosion of pre-harvest dropped citrus fruit provides an enhanced, environmentally friendly method for the release and recovery of valuable coproducts from wasted biomass. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Modification of citrus and apple pectin by power ultrasound: Effects of acid and enzymatic treatment

Pectin-derived oligosaccharides are emerging as a new generation of functional ingredients with new or improved technological and/or bioactive properties as compared to pectin. This work addresses the impact of power ultrasound (US) on the structure of citrus and apple pectin under different experimental conditions of power, amplitude and pectin concentration in aqueous and acid media, as well as in the presence of a pectinase. Results indicated that depolymerisation of both pectin increased with time and intensity of US in aqueous media and their polydispersity decreased. In general, a higher depolymerisation was observed in pectin treated by US in the presence of nitric and citric acids than in water, and hardly any difference was detected between both types of acids. Most of the assays gave rise to high-methoxylated pectin with a degree of esterification above 50%, pointing out their suitability for potential gelling agents. Finally, US did not have any impact in assisted enzymatic hydrolysis on the degree and/or rate of depolymerisation at low and medium levels of pectin concentration (0.5 and 2%), whereas a higher diversity of pectin fragments was found at 5% which could be indicative of a more controlled depolymerisation. These findings highlight the importance of the selection of appropriate US processing conditions to diversify the applications of modified pectin, as well as the potential of US as a prospective alternative to currently used depolymerisation techniques.

Bioactives from fruit processing wastes: Green approaches to valuable chemicals

Fruit processing industries contribute more than 0.5billion tonnes of waste worldwide. The global availability of this feedstock and its untapped potential has encouraged researchers to perform detailed studies on value-addition potential of fruit processing waste (FPW). Compared to general food or other biomass derived waste, FPW are found to be selective and concentrated in nature. The peels, pomace and seed fractions of FPW could potentially be a good feedstock for recovery of bioactive compounds such as pectin, lipids, flavonoids, dietary fibres etc. A novel bio-refinery approach would aim to produce a wider range of valuable chemicals from FPW. The wastes from majority of the extraction processes may further be used as renewable sources for production of biofuels. The literature on value addition to fruit derived waste is diverse. This paper presents a review of fruit waste derived bioactives. The financial challenges encountered in existing methods are also discussed.

Structure characterization, chemical and enzymatic degradation, and chain conformation of an acidic polysaccharide from Lycium barbarum L

An acidic polysaccharide, named as p-LBP, was isolated from Lycium barbarum L. by water extraction and purified by decoloration, ion exchange chromatography, dialysis and gel chromatography, successively. The primary structure analysis was determined by HPAEC-PAD, HPSEC, FT-IR, GC-MS, and NMR. The results showed p-LBP was a homogeneous heteropolysaccharide as a pectin molecule with an average molecular weight of 64kDa p-LBP was an approximately 87nm hollow sphere in 0.05mol/L sodium sulfate solution determined by HPSEC-MALLS, DLS and TEM. A discussion of degradation patterns gave the detailed structural information of p-LBP. Therefore, the results from degraded fragments elucidated that the backbone of p-LBP was formed by →4-α-GalpA-(1→, repeatedly. Partial region was connected by →4-α-GalpA-(1→ and →2-α-Rhap-(1→, alternatively. On the C-4 of partial →2-α-Rhap-(1→ residues existed branches forming by →4-β-Galp-(1→, →3-β-Galp-(1→ or →5-α-Araf-(1→, while on the C-6 of partial →3-β-Galp-(1→ residues existed secondary branches forming by terminal-α-Araf, terminal-β-Galp or →3-α-Araf-(1→.