Antioxidant pectin enriched fractions obtained from discarded carrots (Daucus carota L.) by ultrasound-enzyme assisted extraction

Antioxidant polysaccharide-enriched fractions obtained from olive leaves by ultrasound-assisted extraction with α-amylase inhibition, and antiproliferative activities

Polysaccharide-rich materials were extracted from the alcohol-insoluble solids of Olea europaea l. **leaves. Structural characteristics were determined by colorimetric techniques, FT-IR, GC-MS, SEC/MALS/VD/DRI, and NMR (1H,13C). The extract and its main macromolecular components were characterized to assess their ability toward antioxidant, α-amylase inhibition, and antiproliferative activities. Results revealed that the ultrasound olive leave extract comprises polysaccharides with uronic acid, galactose, arabinose, and glucose in molar percentages of 11.7%, 11.3%, 7.5%, and 4.9% respectively, constituting 41% of the total mass. In addition, polyphenols (21%) and proteins (9%) are associated with these polysaccharides. Further, the extract showed noticeable ORAC and free radical scavenging abilities, in addition to high in vitro antiproliferative activity against Caco-2 colon carcinoma cell lines. Similarly, the extract exhibited a strong, uncompetitive inhibition of α-amylase by 75% in the presence of the extract with 0.75 µg/mL of concentration. This research concludes that ultrasound extraction method can be used for the extraction of polysaccharide-polyphenol-protein complexes. These conjugates exhibit the potential for combined biological activities resulting from a synergistic effect of its compounds, making them promising ingredients for the development of functional food.

The way forward to produce nutraceuticals from agri-food processing residues: obstacle, solution, and possibility

Food matrices contain bioactive compounds that have health benefits beyond nutritional value. The bulk of bioactive chemicals are still present in agro-industrial by-products as food matrices. Throughout the food production chain, there is a lot of agro-industrial waste that, if not managed effectively, could harm the environment, company, and how nutritiously and adequately people eat. It's important to establish processes that maximise the use of agro-industrial by-products, such as biological technologies that improve the extraction and acquisition of bioactive compounds for the food and pharmaceutical industries. As opposed to nonbiological processes, biological procedures provide high-quality, bioactive extracts with minimum toxicity and environmental impact. Fermentation and enzymatic treatment are biological processes for obtaining bioactive compounds from agro-industrial waste. In this context, this article summarises the principal bioactive components in agro-industrial byproducts and the biological methods employed to extract them. In this review efficient utilization of bioactive compounds from agro-industrial waste more effectively in food and pharmaceutical industries has been described.

Bioactive Potential of Carrot-Based Products Enriched with Lactobacillus plantarum

The primary goal of this study was to generate different kinds of functional products based on carrots that were supplemented with lactic acid bacteria. The fact that carrots (Daucus carota sp.) rank among the most popular vegetables in our country led to the convergence of the research aim. Their abundance of bioactive compounds, primarily polyphenols, flavonoids, and carotenoids, offers numerous health benefits. Among the obtained products, the freeze-dried carrot powder (FDCP) variation presented the highest concentrations of total carotenoids (TCs) and β-carotene (BC) of 26.977 ± 0.13 mg/g DW and 22.075 ± 0.14 mg/g DW, respectively. The amount of total carotenoids and β-carotene significantly increased with the addition of the selected lactic acid bacteria (LAB) for most of the samples. In addition, a slight increase in the antioxidant activity compared with the control sample for the FDCP variant, with the highest value of 91.74%, was observed in these functional food products. The content of polyphenolic compounds varied from 0.044 to 0.091 mg/g DW, while the content of total flavonoids varied from 0.03 to 0.66 mg/g DW. The processing method had an impact on the population of L. plantarum that survived, as indicated by the viability of bacterial cells in all the analyzed products. The chromatographic analysis through UHPLC-MS/MS further confirmed the abundance of the bioactive compounds and their corresponding derivatives by revealing 19 different compounds. The digestibility study indicated that carotenoid compounds from carrots followed a rather controlled release. The carrot-based products enriched with Lactobacillus plantarum can be considered newly functional developed products based on their high content of biologically active compounds with beneficial effects upon the human body. Furthermore, these types of products could represent innovative products for every related industry such as the food, pharmaceutical, and cosmeceutical industries, thus converging a new strategy to improve the health of consumers or patients.

Ultrasound-Assisted Enzymatic Protein Hydrolysis in Food Processing: Mechanism and Parameters

Ultrasound has been widely used as a green and efficient non-thermal processing technique to assist with enzymatic hydrolysis. Compared with traditional enzymatic hydrolysis, ultrasonic-pretreatment-assisted enzymatic hydrolysis can significantly improve the efficiency of enzymatic hydrolysis and enhance the biological activity of substrates. At present, this technology is mainly used for the extraction of bioactive substances and the degradation of biological macromolecules. This review is focused on the mechanism of enzymatic hydrolysis assisted by ultrasonic pretreatment, including the effects of ultrasonic pretreatment on the enzyme structure, substrate structure, enzymatic hydrolysis kinetics, and thermodynamics and the effects of the ultrasonic conditions on the enzymatic hydrolysis results. The development status of ultrasonic devices and the application of ultrasonic-assisted enzymatic hydrolysis in the food industry are briefly described in this study. In the future, more attention should be paid to research on ultrasound-assisted enzymatic hydrolysis devices to promote the expansion of production and improve production efficiency.

Sustainable Isolation of Bioactive Compounds and Proteins from Plant-Based Food (and Byproducts)

Plant-based food produces significantly less greenhouse gases, and due to its wealth of bioactive components and/or plant-based protein, it becomes an alternative in a sustainable food system. However, the processing and production of products from plant sources creates byproducts, which can be waste or a source of useful substances that can be reused. The waste produced during the production and processing of food is essentially nutrient- and energy-rich, and it is recognized as an excellent source of secondary raw materials that could be repurposed in the process of manufacturing and preparing food, or as feed for livestock. This review offers an overview of the sources and techniques of the sustainable isolation of bioactive substances and proteins from various sources that might represent waste in the preparation or production of food of plant origin. The aim is to uncover novel approaches to use waste and byproducts from the process of making food to provide this waste food an additional benefit, not forgetting the expectations of the end user, the consumer. For the successful isolation of bioactive ingredients and proteins from food of plant origin, it is crucial to develop more eco-friendly and efficient extraction techniques with a low CO2 footprint while considering the economic aspects.

Carrot Discard as a Promising Feedstock to Produce 2,3-Butanediol by Fermentation with P. polymyxa DSM 365

The valorization of fruit and vegetable residues (such as carrot discard) and their microbial conversion into 2,3-butanediol (BDO) can be considered as a very interesting way to reduce food waste and sustainably originate high value-added products. This work analyzes the valorization of carrot discard as feedstock for 2,3-butanediol (BDO) production by Paenibacillus polymyxa DSM 365. The influences of stirring and the presence of tryptone (nitrogen source) are studied. Furthermore, in order to evaluate the influence of the pre-culture medium (nitrogen source, nutrients, and pH) and the substrate, fermentation assays in simple and mixture semi-defined media (glucose, fructose, and/or galactose) were also carried out. As a result, 18.8 g/L BDO, with a BDO yield of 0.43 g/g (86% of its theoretical value), could be obtained from carrot discard enzymatic hydrolysate at 100 rpm, no tryptone, and pre-culture Häßler medium. No hydrothermal pre-treatment was necessary for BDO production from carrot discard, which increases the profitability of the process. Therefore, 18.8 g BDO, as well as 2.5 g ethanol and 2.1 g acetoin by-products, could be obtained from 100 g of carrot discard (dry matter).

Enzymatic synthesis of fructooligosaccharides: From carrot discards to prebiotic juice

A great volume of carrots is discarded daily worldwide because they do not meet the required shape and size standards. However, they have the same nutritional characteristics as those commercialized, and can be used in different food products. Carrot juice is an excellent matrix for the development of functional foods with prebiotic compounds, such as fructooligosaccharides (FOS). In this work, the production of FOS in situ in carrot juice was evaluated using a fructosyltransferase from Aspergillus niger, produced by solid-state fermentation on carrot bagasse. The enzyme was partially purified 12.5-fold with a total yield of 93 %, and specific activity of 59 U/mg of protein by Sephadex G-105 molecular exclusion chromatography. It was identified by nano LC-MS/MS as a β-fructofuranosidase with a 63.6 kDa MW and it allowed obtaining a FOS yield of 31.6 % in carrot juice. The result was a prebiotic juice with a final concentration of 32.4 mg/mL of FOS. Using the commercial enzyme Viscozyme L a higher yield of FOS (39.8 %) was obtained in carrot juice, corresponding to a total amount of FOS of 54.6 mg/mL. This circular economy scheme allowed the obtention of a functional juice, that may contribute to improve health of consumers.

Antidiabetic activity of Armillaria mellea polysaccharides: Joint ultrasonic and enzyme assisted extraction

Armillaria mellea polysaccharides (AMPs) were obtained by ultrasonic assisted extraction (U), enzyme assisted extraction (E) and ultrasonic-enzyme assisted extraction (UE), respectively. The yield of UE-AMPs (6.32 ± 0.14%) was 1.64 times higher than that of U-AMPs (3.86 ± 0.11%) and 1.21 times higher than that of E-AMPs (5.21 ± 0.09%); meanwhile, the highest total sugar content and the lowest protein content were found in UE-AMPs. AMPs obtained from the three extraction methods had the same monosaccharide composition but in different proportions, allowing UE-AMPs to have the most potent antioxidant activity. The antidiabetic activity of UE-AMPs was investigated in streptozotocin (STZ)-induced diabetic mice. UE-AMPs, when given by gavage, greatly prevented weight loss, increased water intake, and considerably decreased blood glucose levels in diabetic mice, which were dose-dependent (P < 0.05). In addition, UE-AMPs also had a positive effect on the reduction of lipid levels in the blood, oxidative damage and liver function impairment. The pathological observation by hematoxylin-eosin staining (HE) revealed that UE-AMPs protected the organs of mice from diabetic complications (liver disease and nephropathy). Hence, our findings demonstrate that UE-AMPs are a suitable choice for improving diabetes and its complications and have great application prospects in the fields of natural medicine and functional food.

Persistence and remote sensing of agri-food wastes in the environment: Current state and perspectives

Food demand is expected to increase globally by 60-110% from 2005 to 2050 due to diet shifts and population growth. This growth in food demand leads to the generation of enormous agri-food wastes (AFWs), which could be classified into pre-consumption and post-consumption. The AFW represents economic losses for all stakeholders along food supply chains, including consumers. It is reported that the direct financial, social, and environmental costs of food waste are 1, 0.9, and 0.7 trillion USD/year, respectively. Diverse conventional AFW management approaches are employed at the different life cycle levels (entre supply chain). The review indicates that inadequate transportation, erroneous packaging, improper storage, losses during processing, contamination, issues with handling, and expiry dates are the main reason for the generation of AFWs in the supply chain. Further, various variables such as cultural, societal, personal, and behavioral factors contribute to the AFW generation. The selection of a specific valorization technology is based on multiple physicochemical and biological parameters. Furthermore, other factors like heterogeneity of the AFWs, preferable energy carriers, by-products management, cost, end-usage applications, and environmental legislative and disposal processes also play a crucial role in adopting suitable technology. Valorization of AFW could significantly impact both economy and the environment. AFWs have been widely investigated for the development of engineered added-value biomaterials and renewable energy production. Considering this, this study has been carried out to highlight the significance of AFW cost, aggregation, quantification, and membrane-based strategies for its management. The study also explored the satellite remote sensing data for Spatio-temporal monitoring, mapping, optimization, and management of AFW management. Along with this, the study also explained the most recent strategies for AFW valorization and outlined the detailed policy recommendation along with opportunities and challenges. The review suggested that AFW should be managed using a triple-bottom-line strategy (economic, social, and environmental sustainability).

Preparation of branched RG-I-rich pectin from red dragon fruit peel and the characterization of its probiotic properties

Red dragon fruit peel is a pectin-rich fruit waste that is a potential source of prebiotics and whose different sources and structures will influence its prebiotic function. Thus, we compared the effects of three extraction methods on the structure and prebiotic function of red dragon fruit pectin, the results showed that the citric acid extracted pectin produced a high Rhamnogalacturonan-I (RG-I) region (66.59 mol%) and more side-chains of Rhamnogalacturonan-I ((Ara + Gal)/Rha = 1.25), which can promote bacterial proliferation significantly. The side-chains of Rhamnogalacturonan-I may be an important factor in that pectin can promote the proliferation of B. animalis. Our results provide a theoretical basis for the prebiotic application of red dragon fruit peel.

Jabuticaba (Plinia sp.) Peel as a Source of Pectin: Characterization and Effect of Different Extraction Methods

The peel of jabuticaba, a small fruit native to Brazil, has been shown to be a potential source of antioxidants and soluble dietary fibers. In this study, flours prepared from these peels were evaluated as a source of pectin. Different extraction methods were employed: ultrasound (US) extraction followed by low temperature heating (40 °C); in a microwave (MW) without (method 1) or with cellulase (method 2) or hemicellulase (method 3); or in a water bath (method 4). Pectin yields ranged from approximately 18% for methods 1 and 4 up to 22% for enzyme-assisted extractions (methods 2 and 3). Methods that did not employ enzymes resulted in low amounts of methoxyl pectins, as opposed to high amounts of methoxyl pectins obtained after enzyme treatment. Cyanidin-3-O-glucoside (C3G) and ellagic acid were the main phenolic compounds found in jabuticaba peel pectins, with higher C3G levels obtained with enzyme-free extraction (methods 1 and 4). All pectins from jabuticaba peel presented a reddish tone, good emulsifying properties and high swelling capacity. The pectin extracted using US+MW+cellulase (method 2) presented better emulsifying performance (higher values of emulsifying activity and emulsion stability), more effective than commercially available citrus pectin.

Current Challenges in the Sustainable Valorisation of Agri-Food Wastes: A Review

In the upcoming years, the world will face societal challenges arising, in particular, from the impact of climate change and the inefficient use of natural resources, in addition to an exponential growth of the world population, which according to the United Nations (UN) estimations will be 9.8 billion in 2050. This increasing trend requires optimized management of natural resources with the use of value-added waste and a significant reduction in food loss and food waste. Moreover, the recent pandemic situation, COVID-19, has contributed indisputably. Along with the agri-food supply chain, several amounts of waste or by-products are generated. In most cases, these biomass wastes cause serious environmental concerns and high costs to enterprises. The valorisation of the agri-food loss and food industry wastes emerged as a useful strategy to produce certain value-added compounds with several potential applications, namely in the food, health, pharmaceutical, cosmetic, and environmental fields. Therefore, in this review, some of the crucial sustainable challenges with impacts on the valorisation of agri-food loss/wastes and by-products are discussed and identified, in addition to several opportunities, trends and innovations. Potential applications and usages of the most important compounds found in food loss/waste will be highlighted, with a focus on the food industry, pharmaceutical industry, and the environment.

Agri-Food Surplus, Waste and Loss as Sustainable Biobased Ingredients: A Review

Ensuring a sustainable supply of food for the world’s fast growing population is a major challenge in today’s economy, as modern lifestyle and increasing consumer concern with maintaining a balanced and nutritious diet is an important challenge for the agricultural sector worldwide. This market niche for healthier products, especially fruits and vegetables, has increased their production, consequently resulting in increased amounts of agri-food surplus, waste, and loss (SWL) generated during crop production, transportation, storage, and processing. Although many of these materials are not utilized, negatively affecting the environmental, economic, and social segments, they are a rich source of valuable compounds that could be used for different purposes, thus preventing the losses of natural resources and boosting a circular economy. This review aimed to give insights on the efficient management of agri-food SWL, considering conventional and emerging recovery and reuse techniques. Particularly, we explored and summarized the chemical composition of three worldwide cultivated and consumed vegetables (carrots, broccoli and lettuce) and evaluate the potential of their residues as a sustainable alternative for extracting value-added ingredients for the development of new biodynamic products.

A review of sugar beet pectin-stabilized emulsion: extraction, structure, interfacial self-assembly and emulsion stability

In recent years, sugar beet pectin as a natural emulsifier has shown great potential in food and pharmaceutical fields. However, the emulsification performance depends on the molecular structure of sugar beet pectin, and the molecular structure is closely related to the extraction method. This review summarizes the extraction methods of pectin, structure characterization methods and the current research status of sugar beet pectin-stabilized emulsions. The structural characteristics of sugar beet pectin (such as degree of methylation, degree of acetylation, degree of blockiness, molecular weight, ferulic acid content, protein content, neutral sugar side chains, etc.) are of great significance to the emulsifying activity and stability of sugar beet pectin. Compared with traditional hot acid extraction method, ultrasonic-assisted extraction, microwave-assisted extraction, subcritical water-assisted extraction, induced electric field-assisted extraction and enzyme-assisted extraction can improve the yield of sugar beet pectin. At the same time, compared with harsh extraction conditions (too high temperature, too strong acidity, too long extraction time, etc.), mild extraction conditions can better preserve these emulsifying groups in sugar beet pectin molecules, which are beneficial to improve the emulsifying properties of sugar beet pectin. In addition, the interfacial self-assembly behavior of sugar beet pectin induced by the molecular structure is crucial to the long-term stability of the emulsion. This review provides a direction for extracting or modifying sugar beet pectin with specific structure and function, which is instructive for finding alternatives to gum arabic.

Application of Enzyme-Assisted Extraction for the Recovery of Natural Bioactive Compounds for Nutraceutical and Pharmaceutical Applications

Enzyme-assisted extraction (EAE) involves the use of hydrolytic enzymes for the degradation of the cell wall or other cell components. This supports the diffusion of the solvent into the plant or fungal material, leading to easier elution of its metabolites. This technique has been gaining increasing attention, as it is considered an eco-friendly and cost-effective improvement on classical or modern extraction methods. Its promising application in improving the recovery of different classes of bioactive metabolites (e.g., polyphenols, carotenoids, polysaccharides, proteins, components of essential oil, and terpenes) has been reported by many scientific papers. This review summarises information on the theoretical aspects of EAE (e.g., the components of the cell walls and the types of enzymes used) and the most recent discoveries in the effective involvement of enzyme-assisted extraction of natural products (plants, mushrooms, and animals) for nutraceutical and pharmaceutical applications.

By-Products Revalorization with Non-Thermal Treatments to Enhance Phytochemical Compounds of Fruit and Vegetables Derived Products: A Review

The aim of this review is to provide comprehensive information about non-thermal technologies applied in fruit and vegetables (F&V) by-products to enhance their phytochemicals and to obtain pectin. Moreover, the potential use of such compounds for food supplementation will also be of particular interest as a relevant and sustainable strategy to increase functional properties. The thermal instability of bioactive compounds, which induces a reduction of the content, has led to research and development during recent decades of non-thermal innovative technologies to preserve such nutraceuticals. Therefore, ultrasounds, light stresses, enzyme assisted treatment, fermentation, electro-technologies and high pressure, among others, have been developed and improved. Scientific evidence of F&V by-products application in food, pharmacologic and cosmetic products, and packaging materials were also found. Among food applications, it could be mentioned as enriched minimally processed fruits, beverages and purees fortification, healthier and "clean label" bakery and confectionary products, intelligent food packaging, and edible coatings. Future investigations should be focused on the optimization of 'green' non-thermal and sustainable-technologies on the F&V by-products' key compounds for the full-utilization of raw material in the food industry.

The use of ultrasound in the South Cone region. Advances in organic and inorganic synthesis and in analytical methods

In organic and inorganic synthesis and in analytical methods, an external conventional heat source is usually applied to carry out a chemical reaction at a high temperature, or an extraction procedure. In the last decades, the use of ultrasound as an alternative energy source has become an interesting field of research in these topics in the South Cone region (Argentina, Chile, Uruguay, Southern Brazil and Paraguay). For this reason, the present review, covering the period 2009 to mid-2021, is a compilation of ultrasound-assisted synthetic and analytical methodologies.

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.

Pectins and Olive Pectins: From Biotechnology to Human Health

Simple Summary

Pectins comprise complex polysaccharides rich in galacturonic acid, that exert many functions in higher plants as components of the cell walls, together with cellulose or lignin. The food industry has traditionally used pectins as an additive due to their gelling or thickening properties. Pharmaceutical research is also taking advantage of pectin bioactivity, providing evidence of the role of these polysaccharides as health promoters. Fruits and vegetables are natural sources of pectins that can be obtained as by-products during food or beverage production. In line with this, the aim of our study is gathering data on the current methods to extract pectins from fruit or vegetable wastes, optimizing yield and environmentally friendly protocols. Updated information about pectin applications in food or non-food industries are provided. We also point to olives as novel source of pectins that strengthen the evidence that this fruit is as remarkably healthy part of the Mediterranean diet. This work exhibits the need to explore natural bioactive components of our daily intake to improve our health, or prevent or treat chronical diseases present in our society.

Abstract

Pectins are a component of the complex heteropolysaccharide mixture present in the cell wall of higher plants. Structurally, the pectin backbone includes galacturonic acid to which neutral sugars are attached, resulting in functional regions in which the esterification of residues is crucial. Pectins influence many physiological processes in plants and are used industrially for both food and non-food applications. Pectin-based compounds are also a promising natural source of health-beneficial bioactive molecules. The properties of pectins have generated interest in the extraction of these polysaccharides from natural sources using environmentally friendly protocols that maintain the native pectin structure. Many fruit by-products are sources of pectins; however, owing to the wide range of applications in various fields, novel plants are now being explored as potential sources. Olives, the fruit of the olive tree, are consumed as part of the healthy Mediterranean diet or processed into olive oil. Pectins from olives have recently emerged as promising compounds with health-beneficial effects. This review details the current knowledge on the structure of pectins and describes the conventional and novel techniques of pectin extraction. The versatile properties of pectins, which make them promising bioactive compounds for industry and health promotion, are also considered.

Effects of Different Chenopodium formosanum Parts on Antioxidant Capacity and Optimal Extraction Analysis by Taguchi Method

Chenopodium formosanum (CF), rich in nutrients and antioxidants, is a native plant in Taiwan. During the harvest, the seeds are collected, while the roots, stems, and leaves remain on the field as agricultural waste. In this study, di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) radical scavenging ability and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability experiments of seeds, leaves, stems, and roots were designed using the Taguchi method (TM) under three conditions: Ethanol concentration (0-100%), temperature (25-65 °C), and extraction time (30-150 min). The result demonstrates that seeds and leaves have higher radical scavenging ability than stems and roots. Many studies focused on CF seeds. Therefore, this study selected CF leaves and optimized DPPH, ABTS, total phenol content (TPC), total flavonoid content (TFC), and reducing power (RP) through TM, showing that the predicted value of the leaf is close to the actual value. The optimized results of CF leaves were DPPH 85.22%, ABTS 46.51%, TPC 116.54 µg GAE/mL, TFC 143.46 µg QE/mL, and RP 23.29 µg VCE (vitamin C equivalent)/mL. The DPPH and ABTS of CF leaves were second only to the results of CF seeds. It can be seen that CF leaves have the potential as a source of antioxidants and help in waste reduction.

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.

Enzyme-Assisted Aqueous Extraction of Cobia Liver Oil and Protein Hydrolysates with Antioxidant Activity

Cobia, Rachycentron canadum, is a medium-size marine fish with emerging global potential for offshore aquaculture. The processing waste, cobia liver, is a raw material rich in polyunsaturated fatty acid oils. In this study, an environmentally friendly green process, aqueous extraction (AE), was used to extract the cobia liver oil. The effect of cooking time and substrate water ratio on the oil extractability was investigated herein. The cooking time of 15 min, and substrate water ratio of 1:2 obtained the highest extraction efficiency. However, the oil extractability was only 18.8%. Thus, enzyme-assisted aqueous extraction (EAAE) was used to increase oil extractability and recovery of protein hydrolysates. The commercial proteases—including alcalase, papain, trypsin, and pepsin—were employed in pretreated cobia liver in order to increase oil release during AE. The EAAE results showed that maximum oil extractability was 38% by papain pretreatment. EAAE greatly improved the extraction efficiency; the oil extractability was double than that of AE (18.8%). The fatty acid profiles revealed that ω-3 polyunsaturated fatty acid contents of extracted oil obtained from AE and EAAE were 21.3% and 19.5%, respectively. Besides, the cobia liver hydrolysates obtained from EAAE by alcalase, papain, pepsin, and trypsin pretreatment showed scavenge DPPH radical activity with EC50 values of 0.92, 1.03, 0.83, and 0.53 mg, respectively. After in vitro simulated gastrointestinal digestion, the protein hydrolysates exhibited scavenge DPPH radical activity with EC50 values of 1.15, 1.55, 0.98, and 0.76 mg for alcalase, papain, pepsin, and trypsin, respectively. The study showed that the EAAE process can be used for extracting fish oil from fish waste while simultaneously obtaining the protein hydrolysates with antioxidant activity.

Papaya by-products for providing stability and antioxidant activity to oil in water emulsions

The consumption of food with health benefits is growing today worldwide. This study was designed in order to incorporate papaya dietary fibre concentrates (DFCs) from peel and pulp dehydrated with the use of microwave (MW), or convection with hot air (CV) in oil-in- water emulsions. Results of studies indicated that Pulp DFC produced more stability to creaming (18 weeks) than Peel DFC (6 weeks). It was found that peel DFCs exerted up to 30% reduction in lipid peroxidation in comparison to the reference system during storage. Rheological analysis showed a similar behaviour when emulsions were mixed with pulp DFCs either dehydrated by MW or CV, while the dressing with peel DFCs had a much lower consistency than the former. The analysis of the emulsions micro-structure showed a polydisperse system of oil droplets and fiber structures trapping oil. Finally, emulsions with pulp DFCs showed a better consumer´s acceptance. These results also suggested that the use of DFCs may have high industrial potential in contributing to dietary fibre enrichment through technological intervention of emulsion formulation by papaya pulp and peel, increasing antioxidant property, consistency and stability during storage.

Ultrasound-, subcritical water- and ultrasound assisted subcritical water-derived Tartary buckwheat polyphenols show superior antioxidant activity and cytotoxicity in human liver carcinoma cells

The effects of ultrasound-assisted (UAE), subcritical water (SWE) and ultrasound assisted-subcritical water (UA-SWE) treatments on tartary buckwheat polyphenol yield, composition, antioxidant activity and cytotoxicity in human liver carcinoma cells were studied. Folin Ciocalteu assay was used to measure total free phenol content (TFPC), and ABTS, DPPH, FRAP and TEAC assays were used to measure antioxidant activity (AA). Polyphenol characterization was done by LC-MS and cell antioxidant activity (CAA) and cytotoxicity were done using the 2,2'-Azobis-(2-amidinopropane) dihydrochloride [ABAP] and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide [MTT] assays respectively. The highest polyphenol yield was obtained by SWE (53.3 mg g^-1), followed by UA-SWE (31.8 mg g^-1), UAE (19.3 mg g^-1) and HWE (4.2 mg g^-1). Also, SWE had the highest TFPC (7.9 mgGAE/gdw). UAE and UA-SWE showed no differences with TFPC being 6.6 and 6.8 mgGAE/gdw, respectively. The control method (HWE) had the largest number of phenolic compounds identified (25), followed by UAE, SWE and UA-SWE which had 20, 13 and 11 phenolics respectively. Beside phenolic acids, all treatments extracted a number of flavonoids such as flavan-3-ols (catechin-7-O-glucoside, epigallocatechin-3-gallate, epigallocatechin, epicatechin), flavonols (kaempferol-3-O-glucoside, kaempferol, kaempferol-3-rutinoside, rutin, quercetin, quercetin-3-O-glucuronide hyperin), flavones (vitexin, isovitexin, orientin, isoorientin) and anthocyanins (cyanidin-3-O-rutinoside, Cyanidin 3-O-galactoside, cyanidin-3-O-glucoside). SWE gave the highest AA for all tests. However, the AA of those obtained by UAE and UA-SWE did not vary (P < 0.05), but were higher than HWE. Different extracts had best AA at different concentrations (HWE, 300; UAE, 250; SWE, 150; UA-SWE, 200 μg/mL). The IC₅₀ of AA were 270.8 ± 21.3, 198.1 ± 16.0, 97.9 ± 13.5, and 150.4 ± 12.8 μg/mL, respectively for HWE, UAE, SWE and UA-SWE. Generally, SWE and UA-SWE showed the highest cytotoxic activities, followed by UAE, with HWE being the lowest. IC₅₀ of cytotoxicity were 76.1 ± 3.3, 79.5 ± 7.0 and 92.6 ± 4.9 µg/mL for SWE, UA-SWE and UAE, respectively. SWE is a promising method for polyphenol extraction and its combination with ultrasound should be optimized for high yield and conservation of bioactivity.

High Hydrostatic Pressure Assisted by Celluclast® Releases Oligosaccharides from Apple By-Product

A novel and green procedure consisting of high hydrostatic pressure (HHP) aided by a commercial cellulase (Celluclast^®) has been applied to valorise the apple by-product, a valuable source of dietary fibre but mainly composed by insoluble fibre. Optimal conditions for solubilisation of dietary fibre were first determined at atmospheric pressure as 2% (w/v) of substrate concentration and 20 Endo-Glucanase Units of cellulase. Monitoring of polysaccharides and oligosaccharides released from apple by-product was carried out by means of a newly validated HPLC method with refractive index detector. A synergistic effect was observed when the combined HHP plus cellulase treatment was used. Thus, the application of 200 MPa at 50 °C for 15 min enabled a significant increase in the release of water-soluble polysaccharides (1.8-fold) and oligosaccharides (3.8-fold), as well as a considerable decrease in the time required (up to 120-fold), compared to control at 0.1 MPa. Therefore, this technology could be a promising alternative approach to transform an industrial by-product into a novel rich-in-oligosaccharide food ingredient and a step forward into shaping the world of prebiotics.

Extraction of Low Methoxyl Pectin from Fresh Sunflower Heads by Subcritical Water Extraction

Subcritical water extraction (SWE) of pectin from fresh sunflower heads was optimized using the response surface methodology (RSM). The optimal conditions for the maximum yield of pectin (6.57 ± 0.6%) were found to be a pressure of 8 bar, temperature of 120 °C, time of 20 min, and liquid-solid ratio (LSR) of 7 mL/g. The degree of esterification (DE) of pectin was analyzed by titrimetry and Fourier transform infrared (FTIR) methods, which was low methoxyl pectin. The molecular weight (M _w), galacturonic acid (GalA) content, and surface tension of pectin were 11.50 kDa, 82%, and 45.38 mN/m (1.5% w/v), respectively. Moreover, thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis confirmed that pectin had excellent thermal stability. FTIR and ¹H NMR spectra confirmed its structure. This study demonstrated that SWE could be used as a productive and environmentally friendly method for extracting pectin from fresh sunflower heads.

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.

Green Chemistry Extractions of Carotenoids from Daucus carota L.-Supercritical Carbon Dioxide and Enzyme-Assisted Methods

Multiple reviews have been published on various aspects of carotenoid extraction. Nevertheless, none of them focused on the discussion of recent green chemistry extraction protocols, especially for the carotenoids extraction from Daucus carota L. This group of bioactive compounds has been chosen for this review since most of the scientific papers proved their antioxidant properties relevant for inflammation, stress-related disorders, cancer, or neurological and neurodegenerative diseases, such as stroke and Alzheimer's Disease. Besides, carrots constitute one of the most popular sources of carotenoids. In the presented review emphasis has been placed on the supercritical carbon dioxide and enzyme-assisted extraction techniques for the relevant tetraterpenoids. The detailed descriptions of these methods, as well as practical examples, are provided. In addition, the pros and cons of each method and comparison with the standard solvent extraction have been discussed.

Bioactive potential of fruit and vegetable wastes

Fruits and vegetables are essential for human nutrition, delivering a substantial proportion of vitamins, minerals, and fibers in our daily diet. Unfortunately, half the fruits and vegetables produced worldwide end up as wastes, generating environmental issues caused mainly by microbial degradation. Most wastes are generated by industrial processing, the so-called by-products. These by-products still contain many bioactive compounds post-processing, such as macronutrients (proteins and carbohydrates) and phytochemicals (polyphenols and carotenoids). Recently, the recovery of these bioactive compounds from industry by-products has received significant attention, mainly due to their possible health benefits for humans. This chapter focuses on the bioactive potential of fruit and vegetable by-products with possible applications in the food industry (functional foods) and in the health sector (nutraceuticals).