Challenges and solutions of extracting value-added ingredients from fruit and vegetable by-products: a review

Chemical profiles and bioactivities of polyphenolic extracts of Lavandula stoechas L., Artemisia dracunculus L. and Ocimum basilicum L

This study assessed the chemical profiles and bioactivities of the infusions, decoctions and hydroethanolic extracts of tarragon, basil and French lavender. The extracts were chemically characterised (HPLC-DAD-ESI/MS) and their bioactivities were evaluated in vitro. All extracts revealed antimicrobial, antifungal and antioxidant properties. French lavender extracts showed higher total phenolic content, regardless of the extraction method used, and antioxidant and antitumour capacities, but no anti-inflammatory action. All basil and two of the tarragon extracts revealed anti-inflammatory power. Thus, tarragon, basil and French lavender extracts may be considered for inclusion in foods, as preservatives or functional ingredients. Nonetheless, further studies must be conducted to evaluate the pharmacokinetic parameters of the bioactive compounds.

Comparison of different drying technologies for kiwifruit pomace: Changes in physical characteristics, nutritional properties and antioxidant capacities

The objective of this study was to evaluate the impacts of different drying technologies including microwave drying (MD), vacuum microwave drying (VMD), sun drying (SD), vacuum drying (VD), hot air drying (HAD), and vacuum freeze drying (VFD) on the physical characteristics, nutritional properties and antioxidant capacities of kiwifruit pomace in order to realize by-product utilization and improve energy efficiency. Results showed that both MD and VMD significantly reduced drying time by >94.6%, compared to traditional thermal drying which took 14-48 h. MD exhibited the highest content of soluble dietary fiber (9.5%) and the lowest energy consumption. Furthermore, VMD resulted in the highest content of vitamin C (198.78 mg/100 g) and reducing sugar (73.78%), and the antioxidant capacities ranked only second to VFD. Given the financial advantages and product quality, VMD was suggested to be advantageous technology in actual industrial production.

Isolation of Extracellular Vesicles from Agri-Food Wastes: A Novel Perspective in the Valorization of Agri-Food Wastes and By-Products

Agri-food wastes generated by industrial food processing are valorized through the extraction of biomolecules to obtain value-added products useful for various industrial applications. In the present review, we describe the valuable by-products and bioactive molecules that can be obtained from agricultural wastes and propose extracellular vesicles (EVs) as innovative nutraceutical and therapeutic compounds that could be derived from agriculture residues. To support this idea, we described the general features and roles of EVs and focused on plant-derived extracellular vesicles (PDEVs) that are considered natural carriers of bioactive molecules and are involved in intercellular communication between diverse kingdoms of life. Consistently, PDEVs exert beneficial effects (anti-inflammatory, anti-tumor, and immune-modulatory) on mammalian cells. Although this research field is currently in its infancy, in the near future, the isolation of EVs and their use as nutraceutical tools could represent a new and innovative way to valorize waste from the agri-food industry in an ecofriendly way.

Intelligent and active biodegradable biopolymeric films containing carotenoids

There is growing interest in the use of natural bioactive compounds for the development of new bio-based materials for intelligent and active food packaging applications. Several beneficial effects have been associated with the antioxidant and antimicrobial potentials of carotenoid compounds. In addition, carotenoids are sensitive to pH changes and oxidation reactions, which make them useful bioindicators of food deterioration. This review summarizes the current research on the application of carotenoids as novel intelligent and active biodegradable food packaging materials. Carotenoids recovered from food processing by-products can be used in the development of active food packaging materials due to their antioxidant properties. They help maintain the stability of lipid-rich foods, such as vegetable oils. Additionally, when incorporated into films, carotenoids can monitor food oxidation, providing intelligent functionalities.

Trends and challenges of fruit by-products utilization: insights into safety, sensory, and benefits of the use for the development of innovative healthy food: a review

A significant portion of the human diet is comprised of fruits, which are consumed globally either raw or after being processed. A huge amount of waste and by-products such as skins, seeds, cores, rags, rinds, pomace, etc. are being generated in our homes and agro-processing industries every day. According to previous statistics, nearly half of the fruits are lost or discarded during the entire processing chain. The concern arises when those wastes and by-products damage the environment and simultaneously cause economic losses. There is a lot of potential in these by-products for reuse in a variety of applications, including the isolation of valuable bioactive ingredients and their application in developing healthy and functional foods. The development of novel techniques for the transformation of these materials into marketable commodities may offer a workable solution to this waste issue while also promoting sustainable economic growth from the bio-economic viewpoint. This approach can manage waste as well as add value to enterprises. The goal of this study is twofold based on this scenario. The first is to present a brief overview of the most significant bioactive substances found in those by-products. The second is to review the current status of their valorization including the trends and techniques, safety assessments, sensory attributes, and challenges. Moreover, specific attention is drawn to the future perspective, and some solutions are discussed in this report.

Development of functional noodles by encapsulating mango peel powder as a source of bioactive compounds

Antioxidant compounds such as phenolics and carotenoids scavenge reactive oxygen species and protect against degenerative diseases such as cancer and cardiovascular disease when used as food additives or supplements. Mango peel is a by-product of mango which is a good source of bioactive substances such as phytochemicals, antioxidants, and dietary fibers. Unfortunately, the study on mango peel as a potential food additive is very limited. Accordingly, the present study aimed to develop functional noodles through extrusion technology with the encapsulation of mango peel powder as a natural source of bioactive compounds. First, mango peel powder (MPP) was prepared and incorporated during the mixing of ingredients before noodles formation at three different levels (2.5, 5 and 7.5 %). Afterward, the noodles were studied to determine how the encapsulated MPP affects the proximate composition, physicochemical characteristics, polyphenols, carotenoids, anthocyanin, antioxidant and antidiabetic activity, and sensory characteristics. The noodles exhibited a dose-dependent relationship in the content of bioactive components and functional activities with the encapsulation of MPP levels. A significantly (p 0.05) higher value was noticed in 7.5 % of MPP-encapsulated noodles than in any level of MPP encapsulation in noodles. The fiber and protein contents in the MPP-encapsulated noodles were increased by about 0-1.22 % and 0-3.16 %, respectively. However, noodles' color index and water absorption index were decreased with the level of MPP encapsulation. The cooking loss of noodles increased from 4.64 to 5.17, 6.49, and 7.32 %, whereas the cooked weight decreased from 35.11 to 34.40, 33.65, and 33.23 % with 2.5, 5.0, and 7.5 % of MPP encapsulation, respectively. However, MPP was stable during storage of noodles exhibiting higher phenolic content and antioxidant activity than control samples. The sensory evaluation showed that MPP-encapsulated noodles at levels 2.5 and 5 % had approximately similar overall acceptability values with the control sample. As a result of the findings, it appears that adding MPP up to 5 % to noodles improves their nutritional quality without changing their cooking, structural, or sensory aspects. Therefore, mango peel powder can be a potential cheap source for the development of functional noodles and food ingredients.

Comprehensive Update on Carotenoid Colorants from Plants and Microalgae: Challenges and Advances from Research Laboratories to Industry

The substitution of synthetic food dyes with natural colorants continues to be assiduously pursued. The current list of natural carotenoid colorants consists of plant-derived annatto (bixin and norbixin), paprika (capsanthin and capsorubin), saffron (crocin), tomato and gac fruit lycopene, marigold lutein, and red palm oil (α- and β-carotene), along with microalgal Dunaliella β-carotene and Haematococcus astaxanthin and fungal Blakeslea trispora β-carotene and lycopene. Potential microalgal sources are being sought, especially in relation to lutein, for which commercial plant sources are lacking. Research efforts, manifested in numerous reviews and research papers published in the last decade, have been directed to green extraction, microencapsulation/nanoencapsulation, and valorization of processing by-products. Extraction is shifting from conventional extraction with organic solvents to supercritical CO2 extraction and different types of assisted extraction. Initially intended for the stabilization of the highly degradable carotenoids, additional benefits of encapsulation have been demonstrated, especially the improvement of carotenoid solubility and bioavailability. Instead of searching for new higher plant sources, enormous effort has been directed to the utilization of by-products of the fruit and vegetable processing industry, with the application of biorefinery and circular economy concepts. Amidst enormous research activities, however, the gap between research and industrial implementation remains wide.

Optimisation of Polyphenols Extraction from Wild Bilberry Leaves-Antimicrobial Properties and Stability Studies

Polyphenolic extracts from natural sources have received great interest due to their beneficial properties for human health. A method to reduce their variability is to use the design of experiments which allows a limited number of experiments to be performed while exploring the experimental space. Firstly, a 23-full factorial model was used to investigate the polyphenols extraction from wild bilberry leaves. Spectrophotometric data (the content of polyphenols, flavonoids, chlorophyll and radical scavenger activity) and extraction yield were used as responses, and six statistical models were determined depending on the two numerical factors (temperature and alcohol % of ethanol-water mixture) being significant (p < 0.05) in all cases. Numerical optimisation performed by Design Expert 13 software correlates well with the chemical profile determined by high-performance liquid chromatography and the amount of the polyphenol. Afterwards, under the optimised conditions, an extract was prepared in three extraction steps for which composition, chemical stability and antimicrobial properties were evaluated. The antimicrobial potential of the extract was compared with that of the standard compounds (rutin and chlorogenic acid), and the results supported a synergistic effect of the extract components.

Valorization of Second-Grade Date Fruit Byproducts and Nonstandard Sweet Potato Tubers to Produce Novel Biofortified Functional Jam

Byproducts of second-grade dates and sweet potato tubers of noncommercial standard are produced along with the main product and are just as important as the main product but cannot be sold in the open market, as they may not be considered acceptable by consumers. Such byproducts can be valorized through the manufacture of a wide range of functional food products with high market appeal, such as jams. The research approach of this study included measuring antioxidant activity, total flavonoids, polyphenols, physicochemical and color indices, pH, and total sugar, as well as conducting a sensory evaluation, of mixed jams composed of different ratios of date jam (DFJ) to sweet potato jam (SPJ), namely, DP1 (80:20), DP2 (70:30), DP3 (60:40), and DP4 (50:50). To date, no other studies have considered producing mixed jam from dates and sweet potato byproducts. The sensory evaluation results indicated that jam DP4 (consisting of 50% date and 50% sweet potato) had the maximum overall acceptability. This investigation reveals the potential of using mixed byproducts in jams as natural functional ingredients, suggesting the economic value of valorization byproducts as low-cost ingredients to expand the properties, nutritional value, antioxidant content, and overall acceptability of jams. The discovered optimal mixed fruit jam has significant potential for further development as a commercial product.

Polymethoxyflavones from citrus peel: advances in extraction methods, biological properties, and potential applications

Citrus peel, as an effective component of citrus by-products, contains a large number of natural active components, including pectin, vitamins, dietary fiber, essential oil, phenolic compounds, flavonoids, and so on. With the development of the circular economy, citrus peel has attracted extensive concern in the food industry. The exploitation of citrus peel would assist in excavating potential properties and alleviating the environmental burden. Polymethoxyflavones (PMFs) exist almost in citrus peel, which have remarkable biological activities including antioxidant, anti-inflammatory, anti-cancer, and anti-obesity. Therefore, PMFs from citrus peel have the potential to develop as dietary supplements in the near future. Collectively, it is essential to take action to optimize the extraction conditions of PMFs and make the most of the extracts. This review mainly compiles several extraction methods and bioactivities of PMFs from citrus peel and introduces different applications including food processing, pharmaceutical industry, and plant rhizosphere to develop better utilization of citrus PMFs.