A Novel Process for the Recovery of Betalains from Unsold Red Beets by Low-Temperature Enzyme-Assisted Extraction

Green technologies for extracting plant waste functional ingredients and new food formulation: A review

Nowadays, there is a growing interest in food waste recovery by both consumers and companies. Food waste of plant origin is a source of bioactive compounds, such as phenolic acids, anthocyanins, flavonoids, phytosterols, carotenoids, and tocopherols, with well-known antioxidant, anti-glycemic, and antimicrobial properties. The use of green and sustainable technologies to recover bioactive compounds from food waste is a possible solution to valorize waste following the principles of green chemistry. Furthermore, today's consumers are more attracted, informed, and aware of the benefits associated with the consumption of functional foods, and with this in mind, the use of extracts rich in beneficial compounds obtained by green technologies from food waste can be a valid alternative to prepare functional foods. In this review, the recovery of polyphenols and fibers with green technologies from food waste for the formulation of functional foods was presented.

Natural Pigments Recovery from Food By-Products: Health Benefits towards the Food Industry

Given the health risks associated with synthetic colorants, natural pigments have emerged as a promising alternative. These renewable choices not only provide health benefits but also offer valuable technical and sensory properties to food systems. The effective application of natural colorants, however, requires the optimization of processing conditions, exploration of new sources, and development of novel formulations to ensure stability and maintain their inherent qualities. Several natural pigment sources have been explored to achieve the broad color range desired by consumers. The purpose of this review is to explore the current advances in the obtention and utilization of natural pigments derived from by-products, which possess health-enhancing properties and are extracted through environmentally friendly methods. Moreover, this review provides new insights into the extraction processes, applications, and bioactivities of different types of pigments.

Natural Sources of Food Colorants as Potential Substitutes for Artificial Additives

In recent years, the demand of healthier food products and products made with natural ingredients has increased overwhelmingly, led by the awareness of human beings of the influence of food on their health, as well as by the evidence of side effects generated by different ingredients such as some additives. This is the case for several artificial colorants, especially azo colorants, which have been related to the development of allergic reactions, attention deficit and hyperactivity disorder. All the above has focused the attention of researchers on obtaining colorants from natural sources that do not present a risk for consumption and, on the contrary, show biological activity. The most representative compounds that present colorant capacity found in nature are anthocyanins, anthraquinones, betalains, carotenoids and chlorophylls. Therefore, the present review summarizes research published in the last 15 years (2008-2023) in different databases (PubMed, Scopus, Web of Science and ScienceDirect) encompassing various natural sources of these colorant compounds, referring to their obtention, identification, some of the efforts made for improvements in their stability and their incorporation in different food matrices. In this way, this review evidences the promising path of development of natural colorants for the replacement of their artificial counterparts.

Enzyme-Assisted Extraction for the Recovery of Food-Grade Chlorophyll-Based Green Colorant

The aim of the study was to develop a biotechnological approach for the green recovery of chlorophyll from spinach, to be used as a natural food colorant. The plant matrix was characterized in terms of cell wall polysaccharide composition, and a tailored enzymatic mix based on cellulase (40%) xylanase (41%) and polygalacturonase (19%) was formulated. The process variables (temperature (°C), time (h), enzyme mix dose (U/g), zinc concentration (ppm), and buffer/substrate ratio (B/S)) and their interactions were studied by response surface methodology. The overlay plot made it possible to identify the process conditions (T: 25 °C, Zn: 150 ppm e B/S: 17.5, t: <2 h and enzyme mix dose between 12 and 45 U/g) to maximize the amount of chlorophyll, and concurrently, the quality of the green color of the extract. Finally, the novel colorant was applied in the production of a real food.

A comprehensive review of recent development in extraction and encapsulation techniques of betalains

Betalains are attractive natural pigments with potent antioxidant activity, mainly extracted from the roots, tubers, leaves, flowers, and fruits of certain plants and some fungi. They constitute a reliable alternative to synthetic dyes used in the food industry and are considered toxic for consumers. In addition, there is convincing evidence of their health benefits for consumers. However, betalains are highly unstable to environment factors, such as light, heat, oxygen, water activity, and pH change which can be degraded during food processing, handling, storage, or delivery. Therefore, newly developed extraction methods and micro/nano-encapsulation techniques are currently applied to enhance the extraction yield, solve their instability problems, and improve their application in the food industry. This article aims to summarize the new advanced extraction methods of betalains, discussing the recent encapsulation techniques concerning the different encapsulating materials utilization. Betalains, natural pigments with potent antioxidant activity, are increasingly extracted from the roots, tubers, leaves, flowers, and fruits of certain plants and some fungi as safe alternatives to synthetic food dyes used in the food industry. However, their susceptibility to degradation during food processing, storage, and delivery poses challenges. Recent developments in extraction methods (e.g., supercritical fluid, pressurized liquid, ultrasound- and microwave-assisted, and enzyme-assisted) enhance betalain recovery, minimizing degradation. Encapsulation techniques using biopolymers, proteins, lipids, and nanoparticles protect betalains from environmental factors, extending shelf life and enabling controlled release. These advancements offer improved extraction efficiency, reduced solvent use, shorter processing times, and enhanced stability. Integration of these techniques in the food industry presents opportunities for incorporating betalains into various products, including functional foods, beverages, and dietary supplements. By addressing stability challenges, these developments support the production of innovative, healthier food items enriched with betalains. This article provides an overview of recent advancements in betalain extraction and encapsulation, highlighting their potential applications in the food industry.

Progress on the Extraction, Separation, Biological Activity, and Delivery of Natural Plant Pigments

Natural plant pigments are safe and have low toxicity, with various nutrients and biological activities. However, the extraction, preservation, and application of pigments are limited due to the instability of natural pigments. Therefore, it is necessary to examine the extraction and application processes of natural plant pigments in detail. This review discusses the classification, extraction methods, biological activities, and modification methods that could improve the stability of various pigments from plants, providing a reference for applying natural plant pigments in the industry and the cosmetics, food, and pharmaceutical industries.

Complexation of anthocyanins, betalains and carotenoids with biopolymers: An approach to complexation techniques and evaluation of binding parameters

Natural pigments are bioactive compounds that can present health-promoting bioactivities in the human body. Due to their strong coloring properties, these compounds have been widely used as color additives as an alternative to artificial colorants. However, since these pigments are unstable under certain conditions, such as the presence of light, oxygen, and heat, the use of complexation and encapsulation techniques with biopolymers is in demand. Moreover, some functional properties can be achieved by using natural pigments-biopolymers complexes in food matrices. The complexation and encapsulation of natural pigments with biopolymers consist of forming a complex with the aim to make these compounds less susceptible to oxidative and degrading agents, and can also be used to improve their solubility in different media. This review aims to discuss different techniques that have been used over the last years to create natural pigment-biopolymers complexes, as well as the recent advances, limitations, effects, and possible applications of these complexes in foods. Moreover, the understanding of thermodynamic parameters between natural pigments and biopolymers is very important regarding the complex formation and their use in food systems. In this sense, thermodynamic techniques that can be used to determine binding parameters between natural pigments and potential wall materials, as well as their applications, advantages, and limitations are presented in this work. Several studies have shown an improvement in many aspects regarding the use of these complexes, including increased thermal and storage stability. Nonetheless, data regarding the biological effects on the human body and the sensory acceptance of natural pigments-biopolymers complexes in food systems are scarce in the literature.

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.

Biocolorants in food: Sources, extraction, applications and future prospects

Color of a food is one of the major factors influencing its acceptance by consumers. At presently synthetic dyes are the most commonly used food colorant in food industry by providing more esthetically appearance and as a means to quality control. However, the growing concern about health and environmental due to associated toxicity with synthetic food colorants has accelerated the global efforts to replace them with safer and healthy food colorants obtained from natural resources (plants, microorganisms, and animals). Further, many of these biocolorants not only provide myriad of colors to the food but also exert biological properties, thus they can be used as nutraceuticals in foods and beverages. In order to understand the importance of nature-derived pigments as food colorants, this review provides a thorough discussion on the natural origin of food colorants. Following this, different extraction methods for isolating biocolorants from plants and microbes were also discussed. Many of these biocolorants not only provide color, but also have many health promoting properties, for this reason their physicochemical and biological properties were also reviewed. Finally, current trends on the use of biocolorants in foods, and the challenges faced by the biocolorants in their effective utilization by food industry and possible solutions to these challenges were discussed.

Agri-Food Waste from Apple, Pear, and Sugar Beet as a Source of Protective Bioactive Molecules for Endothelial Dysfunction and Its Major Complications

Endothelial damage is recognized as the initial step that precedes several cardiovascular diseases (CVD), such as atherosclerosis, hypertension, and coronary artery disease. It has been demonstrated that the best treatment for CVD is prevention, and, in the frame of a healthy lifestyle, the consumption of vegetables, rich in bioactive molecules, appears effective at reducing the risk of CVD. In this context, the large amount of agri-food industry waste, considered a global problem due to its environmental and economic impact, represents an unexplored source of bioactive compounds. This review provides a summary regarding the possible exploitation of waste or by-products derived by the processing of three traditional Italian crops-apple, pear, and sugar beet-as a source of bioactive molecules to protect endothelial function. Particular attention has been given to the bioactive chemical profile of these pomaces and their efficacy in various pathological conditions related to endothelial dysfunction. The waste matrices of apple, pear, and sugar beet crops can represent promising starting material for producing "upcycled" products with functional applications, such as the prevention of endothelial dysfunction linked to cardiovascular diseases.

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.

Biological Approaches for Extraction of Bioactive Compounds From Agro-industrial By-products: A Review

Bioactive compounds can provide health benefits beyond the nutritional value and are originally present or added to food matrices. However, because they are part of the food matrices, most bioactive compounds remain in agroindustrial by-products. Agro-industrial by-products are generated in large quantities throughout the food production chain and can—when not properly treated—affect the environment, the profit, and the proper and nutritional distribution of food to people. Thus, it is important to adopt processes that increase the use of these agroindustrial by-products, including biological approaches, which can enhance the extraction and obtention of bioactive compounds, which enables their application in food and pharmaceutical industries. Biological processes have several advantages compared to nonbiological processes, including the provision of extracts with high quality and bioactivity, as well as extracts that present low toxicity and environmental impact. Among biological approaches, extraction from enzymes and fermentation stand out as tools for obtaining bioactive compounds from various agro-industrial wastes. In this sense, this article provides an overview of the main bioactive components found in agroindustrial by-products and the biological strategies for their extraction. We also provide information to enhance the use of these bioactive compounds, especially for the food and pharmaceutical industries.

Betalain plant sources, biosynthesis, extraction, stability enhancement methods, bioactivity, and applications

Betalains are plant pigments with functional properties used mainly as food dyes. However, they have been shown to be unstable to different environmental factors. This paper provides a review of (1) Betalain plant sources within several plant families such as Amaranthaceae, Basellaceae, Cactaceae, Portulacaceae, and Nyctaginaceae, (2) The biosynthesis pathway of betalains for both betacyanins and betaxanthins, (3) Betalain extraction process, including non-conventional technologies like microwave-assisted, ultrasound-assisted, and pulsed electrical field extraction, (4) Factors affecting their stability, mainly temperature, water activity, light incidence, as well as oxygen concentration, metals, and the presence of antioxidants, as well as activation energy as a mean to assess stability, and novel food-processing technologies able to prevent betalain degradation, (5) Methods to increase shelf life, mainly encapsulation by spray drying, freeze-drying, double emulsions, ionic gelation, nanoliposomes, hydrogels, co-crystallization, and unexplored methods such as complex coacervation and electrospraying, (6) Biological properties of betalains such as their antioxidant, hepatoprotective, antitumoral, and anti-inflammatory activities, among others, and (7) Applications in foods and other products such as cosmetics, textiles and solar cells, among others. Additionally, study perspectives for further research are provided for each section.

Betalain Extracts from Beetroot as Food Colorants: Effect of Temperature and UV-Light on Storability

Beetroot is a good source of natural food colorants given that it contains significant amount of betalain pigments. This study investigates the three-months storage stability of betalain extracts recovered from unsold beetroot by a specific enzymatic mix. The extract storability was evaluated by the kinetic degradation model of betacyanins and betaxanthins, as well as by pigment color attributes (CIELa*b* parameters) under dark and UV-light exposure at different temperatures (4, 25 and 40 °C). Considering all the tested storage conditions, betaxanthins appeared to be more stable than betacyanins in terms of degradation rate constant, half-life time and activation energy. The effect of UV-light was negligible if the pigment was not exposed to temperatures higher than the room one, since no relevant differences were found between the parameters studied at 4 and 25 °C. Taking into account the visual color, all the investigated color indexes (total color difference, chroma and hue) were mainly affected by temperature, even if mildly high (40 °C), and to a lesser extent by UV-light exposure.

Impact of Cold Storage on Bioactive Compounds and Their Stability of 36 Organically Grown Beetroot Genotypes

In order to exploit the functional properties of fresh beetroot all year round, maintaining the health-benefiting compounds is the key factor. Thirty-six beetroot genotypes were evaluated regarding their content of total dry matter, total phenolic compounds, betalain, nitrate, and total soluble sugars directly after harvest and after cold storage periods of one and four months. Samples were collected from two field experiments, which were conducted under organic conditions in Southwestern Germany in 2017 and 2018. The outcome of this study revealed a significant influence of genotype (p < 0.05) on all measured compounds. Furthermore, significant impacts were shown for storage period on total dry matter content, nitrate, and total phenolic compounds. The medians of nitrate content based on the genotypes studied within the experiment ranged between 4179 ± 1267-20,489 ± 2988 mg kg^-1 DW (dry weight), and that for the total phenolic compounds varied between 201.45 ± 13.13 mg GAE 100 g^-1 DW and 612.39 ± 40.58 mg GAE 100 g^-1 DW (milligrams of gallic acid equivalents per 100 g of dry weight). According to the significant influence of the interactions of storage period and genotype on total soluble sugars and betalain, the decrease or increase in the content of the assessed compounds during the cold storage noted to be genotype-specific. Therefore, to benefit beetroots with retained quality for an extended time after harvest, selection of the suitable genotype based on the intended final use is recommended.