Mango peels as food ingredient / additive: nutritional value, processing, safety and applications

Capture of single or multiple reactive carbonyl species by mangiferin under high temperatures

Reactive carbonyl species (RCS), including acrolein (ACR), methylglyoxal (MGO), and glyoxal (GO), are typically generated in food processing and accumulate in the body for ages, triggering various chronic diseases. Here, we investigated the capture capability and reaction pathways of mangiferin one-to-one and one-to-many on RCS in high temperatures using UPLC-MS/MS. We found that mangiferin can capture ACR/MGO/GO to form their adducts, yet, the ability to capture RCS is arranged in different orders, with ACR > MGO > GO for a single RCS and MGO > ACR > GO for multiple RCS. After synthesizing and identifying the structures of the ACR- and MGO-adducts of MGF, our results indicated that MGF-ACR-MGO produced in the multiple-RCS-MGF system was formed by capturing MGO through MGF-ACR rather than through MGF-MGO capturing ACR, which resulting in higher inhibitory activity of MGF against MGO than against ACR. Then, the capture ability and path of MGF on RCS were verified in the coffee-leaves tea and cake.

Maximizing polyphenol yield: ultrasound-assisted extraction and antimicrobial potential of mango peel

This study investigated the ultrasound-assisted extraction (UAE) techniques used to enhance the polyphenols and antioxidants of mango peel extract (MPE). Additionally, it explored the bacteriostatic activity of MPE against various microorganisms. The UAE method was optimized using response surface methodology (RSM) at different times, temperatures, and ratios, with optimal conditions found to be 35 minutes, 45 °C, and a 1:35 ratio. The optimized yield results for total polyphenol content (TPC) were 17.33 ± 1.57 mg GAE/g, total flavonoid content (TFC) was 12.14 ± 0.29 mg QE/g, and radical scavenging activity (RSA) was 72.11 ± 2.19%. These response models were extremely significant with p-values less than 0.05. MPE showed selective effectiveness against Bacillus cereus, Geobacillus stearothermophilus, and Escherichia coli (E. coli). The results highlight the potential of mango peel as a sustainable source of bioactive compounds, contributing to waste reduction in the food industry and the development of natural antimicrobial agents. This study contributes to further research on the application of MPE in processed foods.

Multifunctional engineering of Mangifera indica L. peel extract-modified bacterial cellulose hydrogel: Unveiling novel strategies for enhanced heavy metal sequestration and cytotoxicity evaluation

The escalating interest in bacterial cellulose (BC) confronts a substantial obstacle due to its biologically inert properties. Hence, BC was modified with ethanolic mango peel extract (EEMP) for various industrial and medical applications of the novel nanocomposite (BC/EEMP). High-performance liquid chromatography (HPLC) delineated the phenolic composition of EEMP, revealing a repertoire of polyphenolic compounds, notably chlorogenic acid, gallic acid, catechin, and ellagic acid. EEMP exhibited broad-spectrum antimicrobial activity against Candida albicans and Staphylococcus aureus, with MIC of 0.018 mg/mL and 0.009 mg/mL, respectively. The removal mechanism of Pb2+ and Ni2+ by BC/EEMP nanocomposite membrane via SEM, EDX, FT-IR, and XRD was characterized, indicating deposition and aggregation of heavy metals with diminished porosity. Heavy metal removal optimization using the Box-Behnken design achieved maximal removal of 95.5 % and 90 % for Pb2+ and Ni2+, respectively. Moreover, BC/EEMP nanocomposite demonstrated selective dose-dependent anticancer activity toward hepatoma (HepG-2, IC50 of 208.8 μg/mL), skin carcinoma (A431, IC50 of 216.7 μg/mL), and breast carcinoma (MDA, IC50 of 197.5 μg/mL), attributed to the enhanced availability of biologically active polyphenolic compounds and physical characteristics of BC. This study underscores the remarkable potential of BC/EEMP nanocomposite for multifaceted industrial and biomedical applications, marking a pioneering contribution to the field.

Water-soluble oat extract enriched with mango peel flour: preparation, characterization and application in Greek yogurt

This study aimed to produce water-soluble oat extract enriched with mango peel flour (MPF) as a source of active compounds and to use this ingredient as a partial substitute for whole milk in Greek yogurt (GY) for its nutritional enrichment. Enriched water-soluble oat extracts (EWSOE) were produced with different concentrations of MPF (0%, 1%, 1.5% and 2%) and characterized in relation to pH, titratable acidity, soluble proteins and total phenolics. Three GY formulations were prepared by partially replacing whole milk with EWSOE and the best formulation (in relation to sensory analyzes and phenolics compounds) was selected for storage study, chemical characterization, and sensory acceptance testing. MPF addition increased soluble proteins and total phenolics in EWSOE. GY formulations prepared with EWSOE had similar sensory scores. During storage, GY prepared with EWSOE containing 2% MPF exhibited changes in pH and titratable acidity and a reduction in total phenolics. Color parameters, cholesterol, and fatty acid composition did not change over 21 days of storage. The major fatty acids in GY were oleic and palmitic acids. The selected product had low lactose content (1.2%), achieved satisfactory sensory acceptance in relation to the evaluated attributes, and had lipid (~6.19%) and protein (~3.96%) contents within regulatory requirements. Additionally, EWSOE is a valuable ingredient in GY preparation, offering beneficial nutritional and functional properties.

Mango peel extracts and mangiferin chromatographic Fourier-transform infrared correlation with antioxidant, antidiabetic, and advanced glycation end product inhibitory potentials using in silico modeling and in vitro assays

Mangifera indica peels are a rich source of diverse flavonoids and xanthonoids; however, generally these are discarded. Computational studies revealed that mangiferin significantly interacts with amino acid residues of transcriptional regulators 1IK3, 3TOP, and 4f5S. The methanolic extract of Langra variety of mangoes contained the least phenol concentrations (22.6 ± 0.32 mg/gGAE [gallic acid equivalent]) compared to the chloroform (214.8 ± 0.12 mg/gGAE) and ethyl acetate fractions (195.6 ± 0.14 mg/gGAE). Similarly, the methanolic extract of Sindhri variety contained lower phenol concentrations (42.3 ± 0.13 mg/gRUE [relative utilization efficiency]) compared with the chloroform (85.6 ± 0.15 mg/gGAE) and ethyl acetate (76.1 ± 0.32 mg/gGAE) fractions. Langra extract exhibited significant α-glucosidase inhibition (IC50 0.06 mg/mL), whereas the ethyl acetate fraction was highly active (IC50 0.12 mg/mL) in Sindhri variety. Mangiferin exhibited significant inhibition (IC50 0.026 mg/mL). A moderate inhibition of 15-LOX was observed in all samples, whereas mangiferin was least active. In advanced glycation end product inhibition assay, the chloroform fraction of Langra variety exhibited significant inhibition in nonoxidative (IC50 64.4 μg/mL) and oxidative modes (IC50 54.7 μg/mL). It was concluded that both Langra and Sindhri peel extracts and fractions possess significant antidiabetic activities. The results suggest the potential use of peel waste in the management and complications of diabetes.

Physicochemical characterization of pectin and mango peel (Mangifera indica L.) from Mexican cultivars

In Mexico, about 40 % of the mango harvest is lost due to marketing problems. Moreover, the mango industry generates peel and seed waste that ranges from 35 to 60 % of the total weight of processed fruits. This unexploited mango biomass represents a potential resource for producing value-added by-products. A market alternative is exploiting the mango peel as a source of biofunctional compounds, such as pectin. This hydrocolloid has applications in the pharmaceutical, cosmetic, and food industries. This study quantified the peel components of the Ataulfo, Panameño, Manila, and Haden cultivars. The mango peel showed a considerable input of dietary fiber (37-45 % DM), minerals (1018-2156 mg/100 g DM), phenols (2123-4851 mg gallic acid equivalent/100 g DM), flavonoids (0.74-2.7 mg quercetin equivalent/g DM) and antioxidant capacity (375-937 μM Trolox equivalent/g DM). The four cultivars presented high methoxyl pectins (66-71 %). The molecular weight of the pectins analyzed was from 957 to 4859 kDa. The Panameño cultivar showed the highest amount of pectin and viscosity concerning the peel of the other cultivars and a higher content of glucomannans (≈28.21 %). The pectin of the Haden cultivar was the only one with arabinoxylans since xylose was not detected in the pectin of the other cultivars. The chemical characteristics of the studied mango peels are promising for their industrialization.

Phenolic content of Thai Bao mango peel and its in-vitro antioxidant, anti-cholinesterase, and antidiabetic activities

Plant phenolics have been known for various biological activities. This study aims to extract and examine the presence of phenolics in Bao mango (Mangifera indica L. var.) peel ethanolic extract (MPE). Further, antioxidant, anti-diabetic (α-amylase, and α-glucosidase inhibitory activity), and anti- Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase (BACE-1) inhibitory activity) efficacy of MPE were determined. The results indicated that mangiferin (8755.89 mg/ 100 g extract) was the major phenolic compound in MPE. An antioxidant mechanism revealed that MPE had a higher radical scavenging ability (4266.70 µmol TE/g extract) compared to reducing power (FRAP) or oxygen radical absorption capacity (ORAC). Further in-vitro enzyme inhibitory assay against diabetic and AD involved enzymes showed that MPE had stronger inhibitory action against an enzyme involved in diabetes compared to their standard drug (Acarbose) (P < 0.05). While a lower IC50 value was observed against AD-involved enzymes compared to their standard drug (donepezil) (P < 0.05). The results show that Thai Bao mango peel byproduct can be a potential source of nutraceuticals to lower diabetes and improve cognitive health.

Alginate Beads with Encapsulated Bioactive Substances from Mangifera indica Peels as Promising Peroral Delivery Systems

Since various bioactive substances are unstable and can degrade in the gastrointestinal tract, their stabilization is crucial. This study aimed to encapsulate mango peel extract (MPE) into edible alginate beads using the ionotropic gelation method for the potential oral delivery of bioactive substances. Mango peels, generally discarded and environmentally harmful, are rich in health-promoting bioactive substances. The alginate beads were examined for entrapment efficiency, particle size, morphology, thermal stability, physiochemical interactions, release profile under gastrointestinal conditions, and antibacterial efficacy. The study demonstrated the successful encapsulation of MPE with an efficiency of 63.1%. The in vitro release study showed the stability of the alginate beads in simulated gastric fluid with a maximum release of 45.0%, and sustained, almost complete release (99.4%) in simulated intestinal fluid, indicating successful absorption into the human body. In both fluids, the MPE release followed first-order kinetics. Encapsulation successfully maintained the antibacterial properties of MPE, with significant inhibitory activity against pathogenic intestinal bacteria. This is the first study on MPE encapsulation in alginate beads, presenting a promising oral delivery system for high-added-value applications in the food industry for dietary supplements, functional foods, or food additives. Their production is sustainable and economical, utilizing waste material and reducing environmental pollution.

Exploring differences in the physicochemical and nutritional properties of mango flours and starches

Mangoes contain several components that are beneficial for health, in addition to being potential sources of starch for the food industry. However, a substantial amount of fruit is lost in the field because it does not meet commercial standards, resulting in food losses and environmental damage. Herein, the physicochemical properties of mango flours and starches obtained from different parts of the fruit of two cultivars were evaluated. Mango peel flours have higher levels of proteins, fibers, minerals, carotenoids, ascorbic acid, and antioxidant activity than pulp flours, in addition to a higher yellowing index and water and oil-holding capacity, and can be used as a functional flour. The pulp flours, with the higher starch content, showed characteristics that make them valuable as a potential ingredient in soft baking and gluten-free products. Mango starches have circular and oval shapes, with a bimodal distribution. All starches showed an A-type crystallinity pattern. Pulp starches showed a higher peak viscosity and breakdown, with a lower setback, and can be used as a thickening or gelling agent. The higher thermal stability of kernel starch suggests its application in sauces, baking, dairy products, and canned foods.

HPLC-DAD quantification of mangiferin, antioxidant potential and essential oil composition of the leaves of five varieties of Mangifera indica L. of North India

Mangifera indica L. (Mango), native of tropical Asia, has enormous genetic diversity. Comparative phytochemical analysis of leaves of five varieties of Mangifera indica viz. Dashahri, Chausa, Langra, Lucknow Safeda and Gola grown in North India was carried out. Mangiferin content (using HPLC) was found to vary from 0.96 g to 3.00 g per 100 g of dry leaves. Essential oil composition (through GC-MS) showed the major components of all the five varieties to be caryophyllene (4.14-46.26%), humulene (3.19-30.45%), caryophyllene oxide (2.98-17.23%) and humulene epoxide 2 (1.56-4.73%). Results indicated that there was a direct relationship between total phenolic and flavonoid contents and DPPH radical scavenging activities. Our studies indicate that M. indica leaves, which are a form of biomass waste, could be used as an economical and renewable source of antidiabetic compound mangiferin as well as other biologically active phytoconstituents having nutraceutical as well as pharmaceutical applications.

Simple one-step treatment for saccharification of mango peels using an optimized enzyme cocktail of Aspergillus niger ATCC 9642

Developing efficient microbiological methods to convert polysaccharide-rich materials into fermentable sugars, particularly monosaccharides, is vital for advancing the bioeconomy and producing renewable chemicals and energy sources. This study focused on optimizing the production conditions of an enzyme cocktail from Aspergillus niger ATCC 9642 using solid-state fermentation (SSF) and assessing its effectiveness in saccharifying mango peels through a simple, rapid, and efficient one-step process. A rotatable central composite design was employed to determine optimal conditions of moisture, time, and pH for enzyme production in SSF medium. The optimized enzyme cocktail exhibited cellulase activity (CMCase) at 6.28 U/g, filter paper activity (FPase) at 3.29 U/g, and pectinase activity at 117.02 U/g. These optimal activities were achieved with an SSF duration of 81 h, pH of 4.66, and a moisture content of 59%. The optimized enzyme cocktail effectively saccharified the mango peels without the need for chemical agents. The maximum saccharification yield reached approximately 81%, indicating efficient conversion of mango peels into sugars. The enzyme cocktail displayed consistent thermal stability within the tested temperature range of 30-60°C. Notably, the highest sugar release occurred within 36 h, with glucose, arabinose, galactose, and xylose being the primary monosaccharides released during saccharification. This study highlights the potential application of Aspergillus niger ATCC 9642 and SSF for enzymatic production, offering a simple and high-performance process for monosaccharide production. The optimized enzyme cocktail obtained through solid-state fermentation demonstrated efficient saccharification of mango peels, suggesting its suitability for industrial-scale applications.

Impact of washing and freezing on nutritional composition, bioactive compounds, antioxidant activity and microstructure of mango peels

Mango peels are widely produced and highly perishable. Disinfectant washing and freezing are among the most used methods to preserve foods. However, their impact on products' properties is conditioned by the foods' features. This study evaluated for the first time the phytochemical composition, antioxidant activity, and microstructure of mango peels washed with peracetic acid (27 mg/mL for 19 min) and frozen at -20 °C for 30 days. Washing decreased the content of vitamin C (-7%), penta-O-galloyl-β-d-glucose (-23 %), catechin (-30 %), and lutein (-24 %), but the antioxidant activity was preserved. Freezing changed mango peels' microstructure, increased free phenolic compounds, namely acid gallic (+36 %) and catechin (+51 %), but reduced bound phenolic compounds (-12 % to -87 %), bound phenolic compounds' antioxidant activity (-51 % to -72 %), and violaxanthin (-51 %). Both methods were considered adequate to conserve mango peels since fiber and the main bioactive compounds (free mangiferin, free gallic acid, and β-carotene) remained unchanged or increased.

Mango Peels as an Industrial By-Product: A Sustainable Source of Compounds with Antioxidant, Enzymatic, and Antimicrobial Activity

Plant waste materials are important sources of bioactive compounds with remarkable health-promoting benefits. In particular, industrial by-products such as mango peels are sustainable sources of bioactive substances, with antioxidant, enzymatic, and antimicrobial activity. Appropriate processing is essential to obtain highly bioactive compounds for further use in generating value-added products for the food industry. The objective of the study was to investigate and compare the biological activity of compounds from fresh and dried mango peels obtained by different conventional methods and unconventional extraction methods using supercritical fluids (SFE). The highest total phenolic content (25.0 mg GAE/g DW) and the total content of eight phenolic compounds (829.92 µg/g DW) determined by LC-MS/MS were detected in dried mango peel extract obtained by the Soxhlet process (SE). SFE gave the highest content of proanthocyanidins (0.4 mg PAC/g DW). The ethanolic ultrasonic process (UAE) provided the highest antioxidant activity of the product (82.4%) using DPPH radical scavenging activity and total protein content (2.95 mg protein/g DW). Overall, the dried mango peels were richer in bioactive compounds (caffeic acid, chlorogenic acid, gallic acid, catechin, and hesperidin/neohesperidin), indicating successful preservation during air drying. Furthermore, outstanding polyphenol oxidase, superoxide dismutase (SOD), and lipase activities were detected in mango peel extracts. This is the first study in which remarkable antibacterial activities against the growth of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) were evaluated by determining the microbial growth inhibition rate after 12 and 24 h incubation periods for mango peel extracts obtained by different methods. Ethanolic SE and UAE extracts from dried mango peels resulted in the lowest minimum inhibitory concentrations (MIC90) for all bacterial species tested. Mango peels are remarkable waste products that could contribute to the sustainable development of exceptional products with high-added value for various applications, especially as dietary supplements.

Valorization potential of Egyptian mango kernel waste product as analyzed via GC/MS metabolites profiling from different cultivars and geographical origins

Increasing attention has been given to mango (Mangifera indica) fruits owing to their characteristic taste, and rich nutritional value. Mango kernels are typically discarded as a major waste product in mango industry, though of potential economic value. The present study aims to outline the first comparison of different mango kernel cvs. originated from different localities alongside Egypt, e.g., Sharqia, Suez, Ismailia, and Giza. Gas chromatography-mass spectroscopy (GC-MS) post silylation analysis revealed that sugars were the major class being detected at 3.5-290.9 µg/mg, with some kernels originating from Sharqia province being the richest amongst other cvs. In consistency with sugar results, sugar alcohols predominated in Sharqia cvs. at 1.3-38.1 µg/mg represented by ribitol, iditol, pinitol, and myo-inositol. No major variation was observed in the fatty acids profile either based on cv. type or localities, with butyl caprylate as a major component in most cvs. identified for the first time in mango. Regarding phenolics, Sedeeq cv. represented the highest level at 18.3 µg/mg and showing distinct variation among cvs. posing phenolics as better classification markers than sugars. Multivariate data analyses (MVA) confirmed that the premium cvs "Aweis and Fons" were less enriched in sugars, i.e., fructose, talose, and glucose compared to the other cvs. Moreover, MVA of Zabdeya cv. collected from three localities revealed clear segregation to be chemically distinct. Sharqia originated mango kernels were rich in sugars (e.g., glucose and fructose), whilst sarcosine esters predominated in other origins.

Optimizing the ultrasonic extraction of polyphenols from mango peel and investigating the characteristics, antioxidant activity and storage stability of extract nanocapsules in maltodextrin/whey protein isolate

In this study, the extraction and nanoencapsulation of mango peel extract (MPE) were investigated to enhance its stability and preserve its antioxidant properties. Initially, using the central composite design (CCD)-response surface methodology (RSM), optimal conditions for the extraction of MPE via an ultrasonic system were determined to be a temperature of 10.53 °C, a time of 34.35 min, and an ethanol concentration of 26.62 %. Subsequently, the extracted extract was spray-dried and nanoencapsulated using three types of coatings: maltodextrin, whey protein isolate (WPI), and their combination. The results showed that nanoencapsulation led to a significant improvement in the stability of phenolic compounds in the extract during storage compared to free extract. Furthermore, capsules prepared with the combined coating exhibited the highest levels of phenolic compounds and antioxidant activity. Therefore, it can be concluded that nanoencapsulation can serve as an effective method for preserving the bioactive properties of MPE.

Mangifera indica L., By-Products, and Mangiferin on Cardio-Metabolic and Other Health Conditions: A Systematic Review

Mango and its by-products have traditional medicinal uses. They contain diverse bioactive compounds offering numerous health benefits, including cardioprotective and metabolic properties. This study aimed to explore the impact of mango fruit and its by-products on human health, emphasizing its metabolic syndrome components. PUBMED, EMBASE, COCHRANE, and GOOGLE SCHOLAR were searched following PRISMA guidelines, and the COCHRANE handbook was utilized to assess bias risks. In vivo and in vitro studies have shown several benefits of mango and its by-products. For this systematic review, 13 studies met the inclusion criteria. The collective findings indicated that the utilization of mango in various forms-ranging from fresh mango slices and mango puree to mango by-products, mango leaf extract, fruit powder, and mangiferin-yielded many favorable effects. These encompassed enhancements in glycemic control and improvements in plasma lipid profiles. Additionally, mango reduces food intake, elevates mood scores, augments physical performance during exercise, improves endothelial function, and decreases the incidence of respiratory tract infections. Utilizing mango by-products supports the demand for healthier products. This approach also aids in environmental conservation. Furthermore, the development of mango-derived nanomedicines aligns with sustainable goals and offers innovative solutions for healthcare challenges whilst being environmentally conscious.

Effects of gamma-radiation on microbial, nutritional, and functional properties of Katimon mango peels: A combined biochemical and in silico studies

Gamma radiation has notable impacts on the flesh of mangoes. In this research, Katimon mangoes were subjected to different levels of irradiation (0.5, 1.0, 1.5, and 2.0 kGy) using a60Co irradiator. The results showed that irradiation significantly reduced the microbial population in the mango peels, with the 1.5 kGy dose showing the most significant reduction. Irradiation also delayed ripening and extended the shelf life of the mango peels. The total fat, protein, ash, moisture, and sugar content of the mango peels were all affected by irradiation. The total protein content, ash content and moisture content increased after irradiation, while the fat content remained relatively unchanged. The sugar content increased in all samples after storage, but the non-irradiated samples had higher sugar levels than the irradiated ones. The dietary fiber content of the mango peels was not significantly affected by irradiation. The vitamin C content decreased in all samples after storage. The titratable acidity and total soluble solids content of the mango peels increased after storage, but there were no significant differences between the irradiated and non-irradiated samples. Antioxidant activity and cytotoxicity assessment highlighted the antioxidant potential and reduced toxicity of irradiated samples. Additionally, the antimicrobial effectiveness of irradiated mango peels was evaluated. The most substantial inhibitory zones (measuring 16.90 ± 0.35) against Pseudomonas sp. were observed at a radiation dose of 1.5 kGy with 150 μg/disc. To identify potential antimicrobial agents, the volatile components of mangoes irradiated with 1.5 kGy were analyzed through GC-MS. Subsequently, these compounds were subjected to in silico studies against a viable protein, TgpA, of Pseudomonas sp. (PDB ID: 6G49). Based on molecular dynamic simulations and ADMET properties, (-)-Carvone (-6.2), p-Cymene (-6.1), and Acetic acid phenylmethyl ester (-6.1) were identified as promising compounds for controlling Pseudomonas sp.

Interaction mechanism of carotenoids and polyphenols in mango peels

In this study, carotenoids and polyphenols were demonstrated to be the major active substances in the crude pigment extracts (CPE) of mango peels, accounting for 0.26 mg/g and 0.15 mg/g, respectively. The interactions between carotenoids and polyphenols in CPE was observed, as evidenced by that polyphenols significantly improved the antioxidant activity and storage stability of carotenoids in the CPE. Meanwhile, scanning electron microscopy showed that polyphenols are tightly bound to carotenoids. To further elucidate the interaction mechanism, the monomers of carotenoids and polyphenols were identified by HPLC and LC-MS analysis. Lutein (203.85 μg/g), β-carotene (41.40 μg/g), zeaxanthin (4.20 μg/g) and α-carotene (1.50 μg/g) were authenticated as the primary monomers of carotenoids. Polyphenols were mainly consisted of gallic acid (95.10 μg/g), quercetin-3-β-glucoside (29.10 μg/g), catechin (11.85 μg/g) and quercetin (11.55 μg/g). The interaction indexes between carotenoid and polyphenol monomer of CPE were calculated. The result indicated that lutein and gallic acid showed the greatest synergistic effect on the scavenging of DPPH and ABTS radical, suggesting the interaction between carotenoids and polyphenols in CPE was mainly caused by lutein and gallic acid. Molecular dynamics simulations and thermodynamic parameters analysis demonstrated that hydrogen bonding, electrostatic interactions, and van der Waals forces played dominant roles in the interaction between lutein and gallic acid, which was confirmed by Raman and X-ray diffraction. These results provided a new perspective on the interaction mechanism between carotenoids and polyphenols, which offered a novel strategy for the enhancement of the activities and stability of bioactive substances.

Using A Protoplast Transformation System to Enable Functional Studies in Mangifera indica L

Mangoes (Mangifera indica L.) are an important kind of perennial fruit tree, but their biochemical testing method and transformation technology were insufficient and had not been rigorously explored. The protoplast technology is an excellent method for creating a rapid and effective tool for transient expression and transformation assays, particularly in plants that lack an Agrobacterium-mediated plant transformation system. This study optimized the conditions of the protoplast isolation and transformation system, which can provide a lot of help in the gene expression regulation study of mango. The most beneficial protoplast isolation conditions were 150 mg/mL of cellulase R-10 and 180 mg/mL of macerozyme R-10 in the digestion solution at pH 5.6 and 12 h of digestion time. The 0.16 M and 0.08 M mannitol in wash solution (WI) and suspension for counting (MMG), respectively, were optimal for the protoplast isolation yield. The isolated leaf protoplasts (~5.4 × 105 cells/10 mL) were transfected for 30 min mediated by 40% calcium-chloride-based polyethylene glycol (PEG)-4000-CaCl2, from which 84.38% of the protoplasts were transformed. About 0.08 M and 0.12 M of mannitol concentration in MMG and transfection solutions, respectively, were optimal for protoplast viability. Under the florescence signal, GFP was seen in the transformed protoplasts. This showed that the target gene was successfully induced into the protoplast and that it can be transcribed and translated. Experimental results in this paper show that our high-efficiency protoplast isolation and PEG-mediated transformation protocols can provide excellent new methods for creating a rapid and effective tool for the molecular mechanism study of mangoes.

Recent advances in bio-based extraction processes for the recovery of bound phenolics from agro-industrial by-products and their biological activity

Usually found bound to other complex molecules (e.g., lignin, hemicellulose), phenolic compounds (PC) are widely present in agro-industrial by-products, and their extraction is challenging. In recent times, research is starting to highlight the bioactive roles played by bound phenolics (BPC) in human health. This review aims at providing a critical update on recent advances in green techniques for the recovery of BPC, focusing on enzymatic-assisted (EAE) and fermentation-assisted extraction (FAE) as well as in the combination of technologies, showing variable yield and features. The present review also summarizes the most recent biological activities attributed to BPC extracts until now. The higher antioxidant activity of BPC-compared to FPC-coupled with their affordable by-product source make them medicinally potent and economically viable, promoting their integral upcycling and generating new revenue streams, business, and employment opportunities. In addition, EAE and FAE can have a biotransformative effect on the PC itself or its moiety, leading to improved extraction outcomes. Moreover, recent research on BPC extracts has reported promising anti-cancer and anti-diabetic activity. Yet further research is needed to elucidate their biological mechanisms and exploit the true potential of their applications in terms of new food products or ingredient development for human consumption.

Modulation of growth, immune response, and immune-antioxidant related gene expression of Nile tilapia (Oreochromis niloticus) reared under biofloc system using mango peel powder

This study aimed to investigate the effects of mango peel powder (MGPP) on growth, innate immunity, and immune-antioxidant related gene expression of Nile tilapia reared under biofloc system. Three hundred Nile tilapia (average weight 14.78 ± 0.05 g) were distributed into 15 fiber tanks (300 L per tank) assigned to five treatments in triplication. Fish were fed basal diet containing different levels MGPP as follows: 0 (MGPP0: control), 6.25 (MGPP 6.25), 12.5 (MGPP 12.25), 25 (MGPP 25), and 50 (MGPP 50) g kg^-1 diet for 8 weeks. Specific growth rate (SGR), weight gain (WG), final weight (FW), feed conversion ratio (FCR), skin mucus of lysozyme (SMLA), and peroxidase activities (SMPA), serum of lysozyme (SL) and peroxidase (SP) were measured every for weeks; while immune-antioxidant-related gene expressions were determined after 8 weeks post-feeding. The results indicated that MGPP 25 diet resulted in higher SGR, WG, FW, and FCR but no significant differences among treatments were noticed. In terms of immune responses, lysozyme and peroxidase activities in mucus and serum were significantly higher in MGPP 12.5 and MGPP 25 diets against the control. Similarly, significant up-regulation of IL-1 and IL-8 gene expressions was observed in fish fed MGPP 25 against the control. However, no significant differences in LBP, GSTa, GPX, and GSR among treatments were observed. Overall, dietary inclusion of MGPP 25 significantly enhanced immune response and immune related gene expressions but not growth performance and antioxidant gene expressions. The results implied that MGPP can be potentially used as an immunostimulants in Nile tilapia culture.

Agro-Industrial Fruit Byproducts as Health-Promoting Ingredients Used to Supplement Baked Food Products

One of the biggest problems faced by food industries is the generation of large amounts of agro-industrial byproducts, such as those derived from fruit processing, as well as the negative effects of their inadequate management. Approximately 1/3 of the food produced worldwide is unused or is otherwise wasted along the chain, which represents a burden on the environment and an inefficiency of the system. Thus, there is growing interest in reintroducing agro-industrial byproducts (both from fruits and other sources) into the processing chain, either by adding them as such or utilizing them as sources of health-promoting bioactive compounds. The present work discusses recent scientific studies on the nutritional and bioactive composition of some agro-industrial byproducts derived from fruit processing, their applications as ingredients to supplement baked foods, and their main biological activities on the consumer’s health. Research shows that agro-industrial fruit byproducts can be incorporated into various baked foods, increasing their fiber content, bioactive profile, and antioxidant capacity, in addition to other positive effects such as reducing their glycemic impact and inducing satiety, all while maintaining good sensory acceptance. Using agro-industrial fruit byproducts as food ingredients avoids discarding them; it can promote some bioactivities and maintain or even improve sensory acceptance. This contributes to incorporating edible material back into the processing chain as part of a circular bioeconomy, which can significantly benefit primary producers, processing industries (particularly smaller ones), and the final consumer.

Membrane Technology for Valorization of Mango Peel Extracts

Mango peel is rich in nutritional and functional compounds, such as carbohydrates, dietary fibers, proteins, and phenolic compounds, with high potential to be applied in the food industry. Most of the investigation about recovery of bioactive compounds from fruit bioproducts involves extraction techniques and further separation of target compounds. There is still a lack of information about the potential of membrane processes to recover the nutritive/functional compounds present in aqueous extracts of those bioproducts. This research is addressed to study the performance of ultrafiltration (UF), followed by nanofiltration (NF) of UF permeates, to fractionate the compounds present in aqueous extracts of mango peel. Both UF and NF concentration processes were carried up to a volume concentration factor of 2.0. Membranes with molecular weight cut-offs of 25 kDa and 130 Da were used in the UF and NF steps, respectively. UF and NF concentrates showed antioxidant activity, attributed to the presence of phenolic compounds, with rejections of about 75% and 98.8%, respectively. UF membranes totally rejected the higher molecular weight compounds, and NF membranes almost totally concentrated the fermentable monosaccharides and disaccharides. Therefore, it is envisaged that NF concentrates can be utilized by the food industry or for bioenergy production.

Woody Canker and Shoot Blight Caused by Botryosphaeriaceae and Diaporthaceae on Mango and Litchi in Italy

In recent years, the cultivation of tropical fruit crops has increased in the Mediterranean basin, especially in southern Italy. In surveys conducted from 2014 to 2019 woody canker and shoot blight were observed on mango plants (cvs. Kent, Keitt, Sensation, Osteen, and Kensington Pride) and litchi plants (cvs. Way Chee and Kwai Mai Pink) cultivated in Sicily. Botryosphaeriaceae and Diaporthaceae were consistently isolated from symptomatic samples. Morphological characterization and multi-locus phylogenies using three genomic loci (a portion of translation elongation factor 1-α gene, a portion of the β-tubulin gene, and an internal transcribed spacer) identified these fungi as Neofusicoccum parvum, Lasiodiplodia theobromae, Botryosphaeria dothidea, Diaporthe foeniculina, and Diaporthe baccae on mango and Diaporthe foeniculina and Diaporthe rudis on litchi. Pathogenicity tests on healthy mango (cv. Kensington Pride) and litchi (cv. Way Chee) plants demonstrated the pathogenicity of the isolates used in the study, and Koch’s postulates were fulfilled for all pathogens. To our knowledge, this is the first report of L. theobromae, B. dothidea, and Diaporthe species on mango in Italy and the first report worldwide of woody canker and shoot blight caused by D. foeniculina and D. rudis on litchi plants.

Fruit peel bioactives, valorisation into nanoparticles and potential applications: A review

Nanotechnology is a rapidly growing field with profound applications in different domains, particularly in food science and technology. Nanoparticles (NPs) synthesis, an integral part of nanotechnology-based applications, is broadly classified into chemical, physical and biosynthesis methods. Chemically sensitive and energy-intensive procedures employed for NPs synthesis are some of the limits of traditional chemical approaches. Recent research has focused on developing easy, nontoxic, cost-effective, and environment-friendly NPs synthesis during the last decade. Biosynthesis approaches have been developed to achieve this goal as it is a viable alternative to existing chemical techniques for the synthesis of metallic nanomaterials. Fruit peels contain abundant bioactive compounds including phenols, flavonoids, tannins, triterpenoids, steroids, glycosides, carotenoids, anthocyanins, ellagitannins, vitamin C, and essential oils with substantial health benefits, anti-bacterial and antioxidant properties, generally discarded as byproduct or waste by the fruit processing industry. NPs synthesized using bioactive compounds from fruit peel has futuristic applications for an unrealized market potential for nutraceutical and pharmaceutical delivery. Numerous studies have been conducted for the biosynthesis of metallic NPs such as silver (AgNPs), gold (AuNPs), zinc oxide, iron, copper, palladium and titanium using fruit peel extract, and their synthesis mechanism have been reported in the present review. Additionally, NPs synthesis methods and applications of fruit peel NPs have been discussed.

Mangiferin: a review of dietary sources, absorption, metabolism, bioavailability, and safety

Mangiferin is a potential candidate for use in nutraceutical and functional food applications due to its numerous bioactivities. However, the low bioavailability of mangiferin is a major limitation for establishing efficacy for use. This review describes current information on known food sources and factors that influence mangiferin contents, absorption, and metabolism features, and recent progress that has come from research efforts to increase the bioavailability of mangiferin. We also list patents that targeted to enhance mangiferin bioavailability. Mangifera indica L. is the major dietary source for mangiferin, a xanthone that varies widely in different parts of the plant and is influenced by many factors that involve plant propagation and post-harvest processing. Mangiferin absorption occurs mostly in the small intestine by passive diffusion with varying absorption capacities in different segments of the gastrointestinal tract. Recent research has led to the development of novel technologies to encapsulate mangiferin in nano/microparticle carrier systems as well as generate mangiferin derivatives to improve solubility and bioavailability. Preclinical studies reported that mangiferin < 2000 mg/kg is generally nontoxic. The safety and the increase in bioavailability are key limiting factors for developing successful applications for mangiferin as a nutritional dietary supplement or nutraceutical.

Production of Extrudate Food with Mango By-Products (Mangifera indica): Analysis of Physical, Chemical, and Sensorial Properties

The novelty of this work is the use of two mango by-products, mango peel and kernel, to obtain an extruded food. As well as the development of this food through a design of mixtures, we conducted sensorial analysis of the food through a hedonic test, in order not only to develop an extruded food with mango by-products, but also to develop a food that will be accepted by the consumer. A simple lattice mixture design was carried out with 14 mixtures, where the components were white corn flour (WCF), mango peel flour (MPF) and mango kernel flour (MKF), both from the Tommy Atkins mango variety. Physical and chemical properties such as the expansion index (EI), hardness, water absorption index (WAI), water solubility index (WSI), total phenols, DPPH and ABTS were evaluated. An optimization region was found that included 3 design points. Mixtures 1, 6 and 12 were evaluated using a nine-point hedonic scale to determine the acceptability of the product. Appearance, taste, and texture of the extrudates was evaluated. The extrudate with the best overall acceptability and the optimum physical and chemical properties contained 58.33% white corn flour, 33.33% mango peel flour and 8.33% mango kernel flour.