Tangerine, banana and pomegranate peels valorisation for sustainable environment: A review

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.

Transforming plant-based waste and by-products into valuable products using various "Food Industry 4.0" enabling technologies: A literature review

The last several years have seen unprecedented strain on food systems as a result of pandemics, climate change, population growth, and urbanization. Thus, academic and scientific communities now view global food security as a critical issue. However, food loss and waste are a major challenge when adopting food security and sustainability strategies, since a large proportion of food is lost or wasted along the food supply chain. In order to use resources efficiently and enhance food security and sustainability, food waste and by-products must be reduced and properly valorized. Plant-based food production generates various by-products which are generally rich in nutrients and bioactive compounds. Emerging technologies have been effectively employed to extract these valuable compounds with health benefits. Recently, Industry 4.0 technologies such as artificial intelligence, the Internet of Things, blockchain, robotics, smart sensors, 3D printing, and digital twins have a great deal of potential for waste reduction and by-products valorization in food industry. Reducing food waste not only benefits the environment, but also reduces greenhouse gas emissions and thus contributes to sustainable resource management. This review provides up-to-date information on the potential of Industry 4.0 for converting plant-based waste and by-products into valuable products. Recent studies showed that innovations in Industry 4.0 provide attractive opportunities to increase the effectiveness of manufacturing operations and improve food quality, safety and traceability. By leveraging Food Industry 4.0, companies can transform plant-based waste and by-products into valuable products and contribute to a more sustainable and efficient food production system.

Synthesis, characterization of hydroxyapatite from pomegranate fruit peel for Cr (VI) adsorption: Process modelling, kinetic and isotherm studies

The present work focuses on preparation of hydroxyapatite from pomegranate peels by precipitation method. The hydroxyapatite derived from pomegranate fruit peels (HA-PP) was characterized by XRD, FT-IR, SEM-EDS and BET techniques. The HA-PP has mesoporous in structure and had an area of 99.021 m2/g. Further HA-PP was used as adsorbent for the removal of Cr (VI) ion particles from K2Cr2O7. The adsorption trials were executed and found the optimized solution using response surface methodology (RSM). The experiments included parameters like pH 2, initial chromium concentration 200 mg/L, adsorbent loading 0.8 g, and contact time 60 min, respectively. Cr (VI) removal was 89.4 % at the optimum combination of these process parameters. A mathematical and statistical optimizing technique response surface methodology (RSM) was applied to verify the interactive effects of various parameters on the adsorption capacity. The analysis of variance (ANOVA) was used to predict the adequacy of the model (F 82.16) shows developed model is valid with R2 value 0.987, and p-value (>0.1). In this the Langmuir adsorption isotherm and the pseudo-second-order kinetic model are well explained for Cr (VI) adsorption onto HA-PP. This reaction is spontaneous and endothermic, as indicated by the negative change in the standard free energy (ΔG0 = -0.1732) and ΔH0 (+4.71) value at the selected temperature. The ΔS0 (+15.89) further confirms that the randomness increased at the solid-solution interface during adsorption.

Enhanced Cellulose Extraction from Banana Pseudostem Waste: A Comparative Analysis Using Chemical Methods Assisted by Conventional and Focused Ultrasound

This study investigates the effectiveness of various chemical methods, both ultrasound-assisted and non-assisted, for extracting cellulose from banana pseudostem (BPS) waste, comparing the results with commercial pine and eucalyptus cellulose fibers. Delignification treatments with NaOH (25% and 30%) and H2O2 (8%) were evaluated, applied with both conventional and focused sonication. Ultrasound-assisted methods, particularly with NaOH, achieved cellulose percentages as high as 99.5%. X-ray diffraction (XRD) analysis revealed that NaOH treatments significantly increased the cellulose crystallinity index, reaching up to 67.9%, surpassing commercial fibers. Scanning electron microscopy (SEM) results showed that NaOH treatments, especially at 30%, improved fiber morphology and exposure. Thermogravimetric analysis (TGA) indicated that methods using NaOH and focused sonication enhanced the thermal stability of the cellulose. Compared to commercial fibers, some samples obtained with the proposed methods demonstrated higher purity, yield, and thermal stability, highlighting the effectiveness of ultrasound-assisted and NaOH methods.

Enhancement in Bacterial Cellulolytic Enzyme Production Using Acid-Pretreated Banana Peel Waste: A Comparative Evaluation

Banana peel waste is one of the major contributors in the issue raised from solid waste, however, it can be valorized effectively due to high content of cellulose and hemicellulose. Significant conversion of banana waste includes cellulolytic enzymes and bioenergy production. In the present study, bacterial cellulase was produced using raw banana peel and ripe banana peel under SSF. Additionally, impact of acid pretreatment was investigated as one of strategy to improve cellulolytic enzyme production. A comparative evaluation of raw and ripe banana peels showed that ripe banana peels showed better enzyme production after pretreatment with 0.5% dilute HCl acid. In the series of enhancement of the enzyme production, temperature and pH of the SSF medium were also investigated, and found temperature 35 °C and pH 6.0 were optimum to produce maximum 3.5-U/ml FPA, 39-U/ml BGL, and 54-U/ml EG in 18-h SSF incubation. The study presented eco-friendly waste management to produce industrial enzyme for its promising application in waste valorization and biorefinery area.

OrangeExpDB: an integrative gene expression database for Citrus spp

BACKGROUND

Citrus is a major fruit crop, and RNA-sequencing (RNA-seq) data can be utilized to investigate its gene functions, heredity, evolution, development, and the detection of genes linked to essential traits or resistance to pathogens. However, it is challenging to use the public RNA-seq datasets for researchers without bioinformatics training, and expertise.

RESULTS

OrangeExpDB is a web-based database that integrates transcriptome data of various Citrus spp., including C. limon (L.) Burm., C. maxima (Burm.) Merr., C. reticulata Blanco, C. sinensis (L.) Osbeck, and Poncirus trifoliata (L.) Raf., downloaded from the NCBI SRA database. It features a blast tool for browsing and searching, enabling quick download of expression matrices for different transcriptome samples. Expression of genes of interest can be easily generated by searching gene IDs or sequence similarity. Expression data in text format can be downloaded and presented as a heatmap, with additional sample information provided at the bottom of the webpage.

CONCLUSIONS

Researchers can utilize OrangeExpDB to facilitate functional genomic analysis and identify key candidate genes, leveraging publicly available citrus RNA-seq datasets. OrangeExpDB can be accessed at http://www.orangeexpdb.com/ .

The Impact of Food Waste Compost, Vermicompost, and Chemical Fertilizers on the Growth Measurement of Red Radish (Raphanus sativus): A Sustainability Perspective in the United Arab Emirates

The pressing need for sustainable agricultural practices, especially with the increasing population, has directed attention towards alternative fertilizers that enhance crop yield while preserving soil integrity and reducing food loss. The current study investigated the comparative efficacy of food waste compost (FOWC), vermicompost, and chemical fertilizers on the growth of red radish. The present work used a systematic experimental design to evaluate plant growth parameters, including radish weight and height. The soil quality was determined by measuring the pH and electrical conductivity for all soil samples. The results indicated a significant variation in red radish fresh weight among different treatments. For example, the 25% vegetable and fruit waste compost (VFWC) treatment demonstrated a relatively high mean fresh weight, while the 50% mixed compost (MC) treatment yielded a much lower mean fresh weight. These numbers underscore the potential efficacy of specific food waste treatments in enhancing plant growth, with vermicompost at 50% and VFWC at 25% showing considerable promise in increasing crop yield. The current study concluded that FOWC and vermicompost significantly improved plant growth, advocating for their use as sustainable and environmentally friendly alternatives to chemical fertilizers. The current findings emphasized the importance of selecting appropriate fertilizer types and concentrations to optimize agricultural productivity and environmental sustainability, supporting the incorporation of food waste into agricultural systems as a beneficial resource.

Recovery of Ellagic Acid from Pomegranate Peels with the Aid of Ultrasound-Assisted Alkaline Hydrolysis

The pomegranate processing industry generates worldwide enormous amounts of by-products, such as pomegranate peels (PPs), which constitute a rich source of phenolic compounds. In this view, PPs could be exploited as a sustainable source of ellagic acid, which is a compound that possesses various biological actions. The present study aimed at the liberation of ellagic acid from its bound forms via ultrasound-assisted alkaline hydrolysis, which was optimized using response surface methodology. The effects of duration of sonication, solvent:solid ratio, and NaOH concentration on total phenol content (TPC), antioxidant activity, and punicalagin and ellagic acid content were investigated. Using the optimum hydrolysis conditions (i.e., 32 min, 1:48 v/w, 1.5 mol/L NaOH), the experimental responses were found to be TCP: 4230 ± 190 mg GAE/100 g dry PPs; AABTS: 32,398 ± 1817 µmol Trolox/100 g dry PPs; ACUPRAC: 29,816 ± 1955 µmol Trolox/100 g dry PPs; 59 ± 3 mg punicalagin/100 g dry PPs; and 1457 ± 71 mg ellagic acid/100 g dry PPs. LC-QTOF-MS and GC-MS analysis of the obtained PP extract revealed the presence of various phenolic compounds (e.g., ellagic acid), organic acids (e.g., citric acid), sugars (e.g., fructose) and amino acids (e.g., glycine). The proposed methodology could be of use for food, pharmaceutical, and cosmetics applications, thus reinforcing local economies.

Utilization of some fruit rinds in small ruminant feeding: nutritional characteristics determination

Every year, thousands of tons of fruit wastes are produced worldwide while most of them remain unused and are released into the environment. Incorporation of these wastes to feedstuffs reduces competition between food and feed, and reduces environmental risks or methane yield in ruminants. Nevertheless, no comprehensive research was available on the nutritional properties of rinds of different fruits in small ruminant feeding. Hence, this research investigates the nutritional potential of some fruit's rinds (Kiwi, Tangerine, Grapefruit, Sweet lemon, Sour lemon, Banana, Mango, Orange, Apple, Peach, and Persimmon) by in vitro ruminal-microbial and standard laboratory methods. Persimmon rind had the higher total phenolic contents (TPC, 22 mg gallic acid equivalents/g dry matter: DM) than the other treatments (P < 0.0001). The ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash contents of banana rind were greater (P < 0.0001), however its DM, relative feed value (RFV), and non-fiber carbohydrates (NFC) were lower than the other treatments (P < 0.0001). A different range of minerals was observed among fruit rinds along with a higher content of potassium (42.5 g/kg DM) and manganese (49 mg/kg DM) in banana rind (P < 0.0001). Persimmon (45.7 ml/200 mg DM) and sweet lemon (75.7 ml/200 mg DM) rinds recorded the lowest and highest potential gas production, respectively (P < 0.0001). Persimmon exhibited a lower percentage of methane (11.5%) rather than other rinds (P < 0.0001). The total volatile fatty acids (TVFA) and metabolizable energy (ME) in sweet lemon, and dry matter digestibility (DMD) and organic matter digestibility (OMD) in tangerine were greater compared with other rinds. The rind of the banana exhibited the highest amounts of titratable acidity (283 mEq×10- 3), acid-buffering capacity (200 mEq×10- 3), and acid-base buffering capacity (260 mEq×10- 3) (P < 0.0001). In conclusion, the present rinds differed in chemical-nutritional characteristics. These rinds may feed as a substitute for conventional forages in the diets of small ruminants on a large scale throughout the year; however, these in vitro findings need to be scientifically validated under in vivo experiments.

Development of a functional cake with probiotics and micro-encapsulated essential oils: Evaluation of nutritional properties, liver protection, and immune boosting

This study used probiotics and micro-encapsulated clove and cinnamon oils to develop a functional cream-stuffed cake based on sweet potatoes flour and rice flour instead of wheat flour. The cake was evaluated for its physical, chemical, and sensory properties and its antioxidant capacity. The protective effect of the cake against liver injury and immunosuppression induced by thioacetamide injection in male rats was also evaluated. The study found that eugenol and cinnamaldehyde were the majority of volatile compounds in the essential oils used in the cake, with values of 78.73 % and 81.57 %, respectively, as determined by GC-MS analysis. The viable counts of added probiotics in the cake ranged from 13.15 to 11.21 log CFU/g and were still above the threshold for health benefits. The cake had an increased dietary fiber and protein content while containing a low-fat percentage compared to a commercial cake sample. The innovative cake also contained higher levels of water-soluble and fat-soluble vitamins and minerals such as iron, calcium, potassium, and zinc. The antioxidant capacity of the cake was evaluated, and it was found to contain 1827.23 mg GAE/100 g of total phenols and 97.13 mg QE/100 g of flavonoids. The cake was also found to have antioxidant activity and was effective in protecting the liver from oxidative stress and inflammation and reducing immunodeficiency associated with liver damage.

Best Combination of Vegetable By-Products for the Shelf-Life Extension of Fresh Pasta

A combination of by-products was studied in fresh handmade pasta. Pomegranate peels and olive oil by-products were used in the range 0-6% (w/w) and properly combined in a total of nine combinations with an equal amount of broccoli by-products (10% w/w). The broccoli by-products were added to improve the sensory acceptance, which was compromised when the two above by-products were added to the dough. To verify the synergic effects, among these by-products, on tagliatelle shelf life, microbiological quality based on the main spoilage groups, sensory properties, appearance of visible molds, pH and moisture content were monitored in all the packaged samples stored at 4 °C. In addition to fortified pasta samples, control tagliatelle was also investigated. A mathematical approach was used to fit experimental data and calculate pasta shelf life. In addition, a mathematical model was also proposed to describe the dependence of the shelf life from each by-product percentage added to the formulation. Results showed that while the control fresh pasta lasted about 3 days for the undesired proliferation of yeasts and coliforms, all fortified samples maintained acceptable quality for at least one week. Depending on the by-product combination, shelf-life values could reach more than 13 days. The best combination of by-products calculated based on the mathematical model, that reached the highest shelf life (13.30 days), corresponded to 10% broccoli by-products combined with 6% olive oil by-products and 6% pomegranate peels.

Dietary Bioactive Compounds: Implications for Oxidative Stress and Inflammation

Nowadays, it has been amply demonstrated how an appropriate diet and lifestyle are essential for preserving wellbeing and preventing illnesses [...].

A comprehensive overview of eco-friendly bio-fertilizers extracted from living organisms

Currently, sustainable agriculture involves ecofriendly techniques, which include biofertilization. Biofertilizers increase plant productivity by improving soil fertility and nutrient content. A wide range of living organisms can be applied as biofertilizers and increase soil fertility without causing pollution due to their biodegradability. The organisms can be microorganisms like bacteria, microalgae, and micro fungi or macro organisms like macroalgae, macro fungi, and higher plants. Biofertilizers extracted from living organisms or their residues will be increasingly used rather than chemical fertilizers, which cause heavy metal accumulation in soil. Biofertilizer use aims for sustainable development in agriculture by maintaining the soil. This will mitigate climate change and related impacts and will also lower many serious diseases resulting from pollution such as cancer, liver and renal failure, and immune diseases. This review is a comprehensive overview of biofertilizers extracted from a range of living organisms from the Kingdoms Monera to Plantae and included bacteria, algae, fungi, and higher plants. Organisms that play a vital role in elevating soil nutrients in a safe, cheap, and ecofriendly manner are included in the review to promote their potential commercial application.

Pomegranate Peel Phytochemistry, Pharmacological Properties, Methods of Extraction, and Its Application: A Comprehensive Review

Pomegranate peel, derived from the processing of Punica granatum L. (pomegranate), has traditionally been considered agricultural waste. However, recent studies have revealed its potential as a rich source of bioactive compounds with diverse pharmacological effects. Pomegranate peel is a rich reservoir of antioxidants, polyphenols, dietary fiber, and vitamins, which contribute to its remarkable bioactivity. Studies have demonstrated the anti-inflammatory, cardioprotective, wound healing, anticancer, and antimicrobial properties of pomegranate peel owing to the presence of phytochemicals, such as gallic acid, ellagic acid, and punicalagin. The extraction of bioactive compounds from pomegranate peel requires a careful selection of techniques to maximize the yield and quality. Green extraction methods, including pressurized liquid extraction (PLE), ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and enzyme-assisted extraction (EAE), offer efficient and sustainable alternatives to traditional methods. Furthermore, pomegranate peel has been utilized in the food industry, where it can significantly enhance the nutritional value, organoleptic characteristics, and shelf life of food products. Pomegranate peel has the potential to be used to develop innovative functional foods, nutraceuticals, and other value-added products, providing new opportunities for the pharmaceutical, cosmetic, and food industries.

Application of carbon from pomegranate husk for the removal of ibuprofen, cadmium and methylene blue from water

The presence of pharmaceutical products, dyes, and toxic metal ions in water is a major problem worldwide. This work developed low-cost pomegranate-based materials to uptake ibuprofen, cadmium and methylene blue from water. Pomegranate husks (PPH) were carbonized at 400 °C to form carbonized pomegranate husk (CPH), and nanoparticles were loaded into the carbon surface (NPH) by co-precipitation. SEM micrographs showed that the morphology of carbon was highly porous compared to pristine pomegranate husk. The data for BET revealed that CPH and NPH, had about a 20-fold increase in surface area of 142 m2/g and 190 m2/g respectively compared with 9.27 m2/g for PPH. The composites exhibited larger pore sizes and volumes. TEM images confirmed the loading of nanoparticles. The FTIR results showed that the materials had on their surface oxygenated groups such as -OH, -C]O, -COC and other groups like -NH and -C]C which are anticipated to play an essential role in the sorption of the pollutants. It was found that removal efficiency increased when there was a progressive increase in pollutant concentration for all adsorbents. The best pH value of the solution for the sorption processes was pH 8. The recorded adsorption capacities at pH 8 for Cd(II), IBU and MB were 92.85, 39.77 and 95.89 mg/g for NPH, 72.60, 32.58 and 80.59 mg/g for CPH and 32.78, 16.12 and 40.79 mg/g for PPH. Contact time studies showed three sorption steps. Step 1: rapid increase at the initial stage. Step 2: marginal uptake. Step 3: plateau. The trends indicated that sorption was influenced by temperature variation. The data for the thermodynamic parameter △Ho suggest that all the sorption processes were endothermic; the obtained positive values indicate this. The △Ho for PPH was between (64.33-69.08 kJ/mol), 82.84-86.03 kJ/mol for CPH and 87.17-88.96 kJ/mol for NPH. For PPH, molecular interactions were physisorption, and chemisorption for CPH and NPH. The △So has positive values, showing increased freedom during the sorption. The adsorbents followed PSO based on uptake processes involving syngenetic mechanisms.

Fortification of Chlorella vulgaris with citrus peel amino acid for improvement biomass and protein quality

The amino acid extract (protein hydrolysate) from various citrus peels was employed as an organic nutrition source for the culture of Chlorella to investigate their effects on the biomass and protein quality of the microalgae. The major amino acids in citrus peels included proline, asparagine, aspartate, alanine, serine, and arginine. The most plentiful amino acids in the Chlorella were alanine, glutamic acid, aspartic acid, glycine, serine, threonine, leucine, proline, lysine, and arginine. Adding the citrus peel amino acid extracts to the Chlorella medium enhanced overall microalgal biomass (more than two folds p < 0.05) and protein content (more than 1.25 fold, p < 0.05). Citrus peel amino acids increase essential amino acids and decrease the non-protein amino acid of Chlorella (p > 0.05). The present research shows that citrus peels have good nutritional quality and could be used for the inexpensive cultivation of Chlorella biomass with potential utility for food application.

Preparation of chitosan/gelatin-based functional films integrated with carbon dots from banana peel for active packaging application

Carbon dots (CDs) were manufactured with banana peels using a hydrothermal method (200 °C for 6 h). The synthesized CDs were spherical particles with a size of 1-3 nm having carboxyl groups and amine groups on the surface. CDs have been impregnated into chitosan/gelatin films to synthesize multifunctional packaging films. The composite film showed a slight decrease in transparency but a significant increase in UV protection properties. The fabricated film displayed strong antioxidant efficacy showing >74 % DPPH and 99 % ABTS radical scavenging potential. The film also unveiled substantial antibacterial activity against the foodborne pathogenic bacteria, Listeria monocytogenes, fully eliminating the growth of these bacteria within 6 h of exposure. The chitosan/gelatin film containing CD was used for minced meat packaging, and the film delayed bacterial growth (< 1 Log CFU/g after 24 h) and maintained the meat color even after 24 h of storage at 20 °C. The CD-added chitosan/gelatin functional film has a high probability of application in active food packaging, especially for extending the shelf life of packaged meat and maintaining its aesthetic quality.

Development of chicken tender pops by utilizing pomegranate peel powder

Pomegranate peel powder (PPP) is a rich source of many bioactive components particularly polyphenols that are interlinked to various technological and functional properties. In the present study, chicken tender pops were developed with incorporation of PPP, and its effect on quality attributes and storage stability of the product were evaluated. The treatments were formulated using 0%, 3%, 6%, and 9% PPP in replacement of chicken. The physicochemical properties, texture profile, instrumental color, sensory attributes, and storage stability were assessed for 21 days at refrigeration temperature, at a regular interval of 7 days. The results indicated that the inclusion of PPP significantly (p < .05) increased the dietary fiber from 0.25% in T0 to 1.45% in T3 at Day 0 and WHC 43.60% ± 0.02 in T0 to 49.36% ± 0.02 in T3 at Day 0, whereas the moisture content significantly reduced from 60.05% ± 0.03 in T0 to 55.08% ± 0.01 in T3 at the start of the study. In addition, the values of TBARS were significantly (p < .05) reduced for treated samples 0.72 mg MDA/Kg in T3 as compared to control 1.17 mg MDA/Kg on the 21st day of storage, whereas a significant increase (p < .05) in TPC from 0.90 mg GAE/g to 3.87 mg GAE/g in T0 to T3 was observed at the start of the study. For TPA, a significant (p < .05) increase was noticed in hardness, chewiness, and gumminess, whereas cohesiveness and springiness showed a non-significant (p > .05) change in treated samples in relation to control, and the instrumental color (L* and a*) decreased significantly. However, pH, crude fiber, fat, ash, and protein content showed non-significant (p > .05) variations over time. The sensory evaluation suggested that chicken tender pops supplemented with 6% PPP (T2) presented high overall acceptability and balanced organoleptic properties. Hence, it can be concluded that PPP can be effectively utilized as a natural fiber source, antioxidant, and antimicrobial agent in novel functional foods.

Pomegranate Peel Powder: In Vitro Efficacy and Application to Contaminated Liquid Foods

In this study the recycling of pomegranate peel powder (PPP) was proposed. In particular, the use of powder loaded in a silk fibroin polymeric matrix to create an active pad was tested. For the sake of comparison, the powder alone was also analysed. Both powder and active pad efficacy was assessed in two different food systems, soymilk (rich in proteins), preliminarily contaminated with Pseudomonas spp. and yeasts, and apple juice (rich in carbohydrates), preliminarily contaminated with Alyciclobacillus acidoterrestris. Three different concentrations of powder alone and powder in the pad were tested (5%, 7.5% and 10% w/v) in both types of beverages. To assess a possible dependence of the efficacy on the powder granulometry, different powder sizes were preliminarily analysed on Pseudomonas spp. and yeasts using an in vitro test. PPP was effective on both Pseudomonas spp. and yeasts. No significant differences appeared among the tested granulometries and therefore in the subsequent tests powder with an average diameter of 250 µm was used. Results recorded with soymilk and apple juice were different. When applied to the soymilk, the activity of PPP in the pad was less effective than that recorded when the powder was directly added to the beverage. With the two highest powder concentrations directly added to food, more than four log cycle reductions in Pseudomonas spp. and yeast cells were recorded, compared to soymilk without any powder. Compared to the control sample, all the soymilk samples either with PPP or with the active pad showed a delayed microbial and fungal growth. When applied to apple juice, both powder and pad were effective at completely inhibiting the proliferation of A. acidoterrestris (<102 CFU/g).

The phenolics, antioxidant activity and in vitro digestion of pomegranate (Punica granatum L.) peels: an investigation of steam explosion pre-treatment

Pomegranate peels, the main byproduct of pomegranate production, are rich in phenolic compounds that are known for their effective antioxidant properties and have vast application prospects. In this study, steam explosion, an environmentally friendly technique, was applied to pretreat pomegranate peels for phenol extraction. We investigated the effects of explosion pressure, duration, and particle size on the content of total and individual phenolics, and antioxidant activity of pomegranate peels before and after in vitro digestion. The optimal conditions for a steam explosion for pomegranate peels in terms of total phenol content were a pressure of 1.5 MPa, a maintenance time of 90 s, and a particle size of 40 mesh. Under these conditions, pomegranate peel extract presented a higher yield of total phenols, gallic acid, and ellagic acid. However, it also had a lower content of punicalin and punicalagin, compared to the unexploded peels. There was no improvement in the antioxidant activity of pomegranate peels after the steam explosion. Moreover, the content of total phenol, gallic acid, ellagic acid, punicalin, and punicalagin, as well as the antioxidant activity of pomegranate peels, all increased after gastric digestion. Nevertheless, there was a large variation in the pomegranate peel processed by different pressure, duration, and sieve fractions. Overall, this study demonstrated that steam explosion pre-treatment could be an efficient method for improving the release of phenolics, especially gallic acid, and ellagic acid, from pomegranate peels.

Valorisation of agri-food waste to fertilisers is a challenge in implementing the circular economy concept in practice

The area of agricultural wastes valorisation to fertilizers is attracting growing attention because of the increasing fertilizer prices of fertilizers and the higher costs of waste utilization. Despite the scientific and political interest in the concept of circular economy, few studies have considered the practical approach towards the implementation of elaborated technologies. This article outlines innovative strategies for the valorisation of different biobased wastes into fertilizers. The present work makes a significant contribution to the field of new ideas for waste biomass management to recover significant fertilizer nutrients. These results emphasize the importance of the biomass use as a base of renewable resources, which has recently gained special importance, especially in relation to the outbreak of pandemia and war. Broken supply chains and limited access to deposits of raw materials used in fertilizer production (natural gas, potassium salts) meant that now, as never before, it has become more important and feasible to implement the idea of a circular economy and a green deal. We have obtained satisfactory results that demonstrate that appropriate management of biological waste (originating from agriculture, food processing, aquaculture, forest, pharmaceutical industry, and other branches of industry, sewage sludge) will not only reduce environmental nuisance (reducing waste heaps), but will also allow recovery of valuable materials, such as nitrogen (especially valuable amino acids), phosphorus, potassium, microelements, and biologically active substances with properties that stimulate plant growth. The results reported here provide information on production of biobased plant protection products (bioagrochemicals) from agri-food waste. This work reports an overview of biopesticides and biofertilisers production technologies and summarizes their properties and the mechanisms of action.

GC-MS Profiling, In Vitro Antioxidant, Antimicrobial, and In Silico NADPH Oxidase Inhibition Studies of Essential Oil of Juniperus thurifera Bark

Juniperus thurifera is a native species to the mountains of the western Mediterranean region. It is used in traditional medicine as a natural treatment against infections. The present study aimed to carry out the chemical analysis and evaluate the antioxidant, antimicrobial, as well as in silico inhibition studies of the essential oils from Juniperus thurifera bark (EOEJT). Chemical characterization of EOEJT was done by gas chromatography (GC-MS). We have performed three antioxidant assays (Reducing power (FRAP), 2, 2-diphenylpicrylhydrazyl (DPPH), and total antioxidant capacity (TAC)) of the EOEJT. We next evaluated the antimicrobial activity against in silico study, which was carried out to help evaluate the inhibitory effect of EOEJT against NADPH oxidase. Results of the GC/MS analysis revealed seven major compounds in EOEJT wherein muurolol (36%) and elemol (26%) were the major components. Moreover, EOEJT possessed interesting antioxidant potential with an IC50 respectively of 21.25 ± 1.02 μg/mL, 481.02 ± 5.25 μg/mL, and 271 μg EAA/mg in DPPH, FRAP, and total antioxidant capacity systems. Molecular docking of EOEJT in NADPH oxidase active site showed inhibitory activity of α-cadinol and muurolol with a glide score of −6.041 and −5.956 Kcal/mol, respectively. As regards the antibacterial and antifungal capacities, EOEJT was active against all tested bacteria and all fungi, notably, against Escherichia coli K12 with an inhibition diameter of 21 mm and a MIC value of 0.67 mg/mL, as well as against Proteus mirabilis ATCC 29906 with an inhibition diameter of 18.33 ± 1.15 mm and a MIC value of 1.34 mg/mL. A more pronounced effect was recorded for the fungal pathogens Fusarium oxysporum MTCC 9913 with inhibition of 37.44 ± 0.28% and MIC value of 6.45 mg/mL, as well as against Candida albicans ATCC 10231 with an inhibition diameter of 20.33 ± 1.15 mm and a MIC value of 0.67 ± 0.00 mg/mL. Altogether, these results highlight the importance of EOEJT as a source of natural antibacterial and antioxidant drugs to fight clinically important pathogenic strains.

Myco-biorefinery approaches for food waste valorization: Present status and future prospects

Increases in population and urbanization leads to generation of a large amount of food waste (FW) and its effective waste management is a major concern. But putrescible nature and high moisture content is a major limiting factor for cost effective FW valorization. Bioconversion of FW for the production of value added products is an eco-friendly and economically viable strategy for addressing these issues. Targeting on production of multiple products will solve these issues to greater extent. This article provides an overview of bioconversion of FW to different value added products.

Sorption Isotherms and Thermodynamic Properties of Pomegranate Peels

Convective drying is the most widely used technique to stabilize by-products in the food industry, permitting later processing. A thorough knowledge of the relationship between moisture content and water activity allows the optimization of not only drying operations, but the settings of storage conditions. Thus, the thermodynamic properties of pomegranate peels were determined during the desorption process. Experimental sorption isotherms at 20, 30, 40 and 50 °C showed type II Brunauer behavior. Eight different theoretical and empirical equations were fitted to the experimental results; the theoretical GAB model and the empirical Peleg model were the ones that achieved the best fit (R² of 0.9554 and 0.974, respectively). The Clausius–Clapeyron equation and the enthalpy–entropy compensation theory were used to determine the thermodynamic parameters. The isosteric heat determined from the sorption isotherms decreased regularly as the equilibrium moisture content rose (from 8423.9 J/mol at 0.11 kgH₂O/kg d.m. to 3837.7 J/mol at 0.2 kgH₂O/kg d.m.). A linear compensation was observed between enthalpy and entropy, which indicated an enthalpy-controlled sorption process.

Microwave-Assisted Hydrothermal Carbonization of Pomegranate Peels into Hydrochar for Environmental Applications

Several studies have reported that the hydrothermal carbonization method (HTC) of agricultural waste is able to produce a solid residue with interesting properties for the adsorption of organic pollutants from contaminated water. This work represents a facile method to prepare hydrochar (HC) from pomegranate peels’ waste using the microwave-assisted hydrothermal carbonization method (MHTC) at 200 °C for 1 h with a mass ratio of peel to water = 1:10. Activated hydrochar (AHC) was prepared by in situ chemical activation using ZnCl2 and MHTC. Several techniques have been applied to characterize the prepared samples as FTIR, XRD, TEM and SEM. The samples were investigated for their possible use as adsorbents of methylene blue (MB) dye. The results confirm the formation of amorphous hydrochar with a porous structure. The pH of zero point charge (pHzpc) is 4.3 and 4.6 for HC and AHC samples, respectively. The maximum adsorption capacity of HC and AHC samples are 194.9 and 12.55 mg/g (i.e., mg of adsorbate/g of adsorbent), respectively.

Recovery from Food Waste-Biscuit Doughs Enriched with Pomegranate Peel Powder as a Model of Fortified Aliment

The aim of the present work is the characterization of biscuit doughs enriched with pomegranate peel powder (PPP) at 3 (PPP3) and 5 (PPP5) wt% in the prospect of developing a fortified aliment as a support of the therapy of chronic inflammatory diseases of the intestinal tract. The total phenolic content of the powder was preliminarily evaluated. Then, the main compounds present in the PPP were identified by HPLC-ESI-TOF-MS analysis, being mainly hydrolysable tannins. The PPP was then treated at 180 °C for 20 min to mimic the baking treatment, and its water-soluble fraction (PPPwsf) was then added in the Caco-2 cell culture as a model of the intestinal epithelial barrier to verify its dose-dependent toxicity, ability in counteracting the oxidative stress, and anti-inflammatory action. Rheological experiments were performed to predict the macroscopic behavior of the PPP-added doughs during lamination and biscuit baking. SEM investigations gave their contribution to the microscopic comprehension of the dough structure. Finally, a consumer panel composed by thirty volunteers was enrolled to express its opinion on the sensory agreeableness of the biscuits prepared with two different concentrations of PPP compared with the reference dough. The discussion is focused on the biological effects of the main components found in the PPP.

Prevention of Enzymatic Browning by Natural Extracts and Genome-Editing: A Review on Recent Progress

Fresh fruits and vegetable products are easily perishable during postharvest handling due to enzymatic browning reactions. This phenomenon has contributed to a significant loss of food quality and appearance. Thus, a safe and effective alternative method from natural sources is needed to tackle enzymatic browning prevention. The capabilities of natural anti-browning agents derived from plant- and animal-based resources in inhibiting enzymatic activity have been demonstrated in the literature. Some also possess strong antioxidants properties. This review aims to summarize a recent investigation regarding the use of natural anti-browning extracts from different sources for controlling the browning. The potential applications of genome-editing in preventing browning activity and improving postharvest quality is also discussed. Moreover, the patents on the anti-browning extract from natural sources is also presented in this review. The information reviewed here could provide new insights, contributing to the development of natural anti-browning extracts and genome-editing techniques for the prevention of food browning.

Comparison and Optimization of Operational Parameters in Removal of Heavy Metal Ions from Aqueous Solutions by Low-Cost Adsorbents

Removal of heavy metal ions such as cadmium, lead, chromium, and iron from industrial wastewater is one of the most critical environmental problems. In this research, natural and low-cost adsorbents like the tangerine peel, bovine gut, tea waste, and sunflower seed hull were used for adsorption of heavy metals, such as chromium and iron, from contaminated solutions. The effects of environmental factors such as contact time, pH, the amount of adsorbent dose, and the initial concentration of metal ions in synthetic solution were investigated to obtain optimal conditions for the adsorption of heavy metal ions. For separation of chromium metal ion from aqueous solution, tea waste, tangerine peel, bovine gut, and sunflower seeds hull showed adsorption capacity of 85%, 51%, 46%, and 34%, respectively, while for the adsorption of iron (III), the adsorption capacities of tea waste, bovine gut, tangerine peel, and sunflower seeds hull were 96%, 96%, and 87%, respectively. The adsorption isotherms were in decent correlation with the Langmuir and Freundlich isotherm models. The adsorption kinetics of iron and chromium has a proper validation with the pseudo-second-order kinetic model. The BET and FTIR analyses were also reported to investigate the adsorption properties. This study suggests these adsorbents as low-cost and economical materials for the adsorption of chromium and iron ions with a high adsorption rate.

Functional Compounds from Banana Peel Used to Decrease Oxidative Stress Effects

Banana peel, a little-used waste, contains a high amount of biologically active compounds. The aim of the study is to demonstrate in vitro, the antioxidant, cytotoxic, and antimicrobial effects of hydroalcoholic extracts from yellow (BP) and red (BPR) banana peels. The analysis of the extracts by Capillary Zone Electrophoresis (CZE) has confirmed the presence of several bioactive compounds. BPR has a higher in vitro antioxidant activity than BP, which correlates with a significant cytotoxic, antimicrobial effect, with a UVA/UVB rate of 0.9. In the case of BPR, the results confirm the presence of isoquercitrin and kaempferol in a 1:3 ratio. The bioactive compounds from the extracts have shown a different interaction with HCT-8 cell lines and with tested bacterial strains with pathogenic properties. The HCA analysis proved the biological value of BPR to reduce oxidative stress and its potential use in natural products.

Antibacterial activities of indigenous yeasts isolated from pomegranate peels (Punica granatum L.)

Pomegranate peels (PGPs) are known to have the potential as antibacterial not only from their nutrient content but also the microflora. The activities might be caused by the existence of indigenous yeast that can be utilized to inhibit the growth of pathogenic bacteria. This study aims to identify antibacterial and antioxidant activity of indigenous yeast isolated from PGP. The research was conducted by experimental methods and followed by descriptive analysis. The study was done by the isolation of indigenous yeast from PGPs, which was identified using the rRNA sequence analysis of internal transcribed spacer (ITS) region with the primers of ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3') and then compared with Basic Local Alignment Search Tools (BLAST) algorithm toward the GenBank. Antibacterial activities of indigenous yeast were tested with agar plug diffusion and time kill test toward Escherichia coli and Staphylococcus aureus. The yeast identification obtained two isolates similar to Hanseniaspora uvarum CBS 314 and two isolates of Pichia kudriavzevii ATCC 6258 which have antibacterial activity against E. coli and S. aureus. P. kudriavzevii PGP D4 have best antimicrobial activities with a strong activity against E. coli (±9 mm) and medium activity against S. aureus (±3.1 mm).

Biobased composites from agro-industrial wastes and by-products

The greater awareness of non-renewable natural resources preservation needs has led to the development of more ecological high-performance polymeric materials with new functionalities. In this regard, biobased composites are considered interesting options, especially those obtained from agro-industrial wastes and by-products. These are low-cost raw materials derived from renewable sources, which are mostly biodegradable and would otherwise typically be discarded. In this review, recent and innovative academic studies on composites obtained from biopolymers, natural fillers and active agents, as well as green-synthesized nanoparticles are presented. An in-depth discussion of biobased composites structures, properties, manufacture, and life-cycle assessment (LCA) is provided along with a wide up-to-date overview of the most recent works in the field with appropriate references. Potential uses of biobased composites from agri-food residues such as active and intelligent food packaging, agricultural inputs, tissue engineering, among others are described, considering that the specific characteristics of these materials should match the proposed application.

Isotherm, kinetics, and adsorption mechanism studies of diethylenetriaminepentaacetic acid-modified banana/pomegranate peels as efficient adsorbents for removing Cd(II) and Ni(II) from aqueous solution

Two novel absorbents were synthesized for the first time by banana and pomegranate peels using diethylenetriaminepentaacetic acid (DTPA) modification to eliminate Cd(II) and Ni(II) of sewage. The DTPA-modified peels performed significantly higher adsorption capacity than unmodified materials. The maximum adsorption capacities of DTPA-modified banana/pomegranate peel were 46.729/46.296 mg/g for Cd(II), and 29.240/16.611 mg/g for Ni(II). Adsorption isotherm and kinetics models were simulated to determine their removal efficiency and potential for recovery of these two heavy metals. As the results, the adsorption reached equilibrium within 5 min and was well described by the pseudo-second order model and Langmuir isotherm. The surface morphology analysis of the synthetic materials by Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy, Fourier Transform Infrared spectroscopy, and X-ray Photoelectron Spectroscopy, implied that ion exchange, complexation, and physical adsorption may together contribute to Cd(II) and Ni(II) loading on DTPA-modified peels. This study demonstrates the feasibility of waste peels as cost-efficient bio-absorbents to remove Cd(II) and Ni(II) in sewage systems, and discovers potential adsorption mechanism of efficiency improvements after DTPA modification.

Recovery of Banana Waste-Loss from Production and Processing: A Contribution to a Circular Economy

Banana is a fruit grown mainly in tropical countries of the world. After harvest, almost 60% of banana biomass is left as waste. Worldwide, about 114.08 million metric tons of banana waste-loss are produced, leading to environmental problems such as the excessive emission of greenhouse gases. These wastes contain a high content of paramount industrial importance, such as cellulose, hemicellulose and natural fibers that various processes can modify, such as bacterial fermentation and anaerobic degradation, to obtain bioplastics, organic fertilizers and biofuels such as ethanol, biogas, hydrogen and biodiesel. In addition, they can be used in wastewater treatment methods by producing low-cost biofilters and obtaining activated carbon from rachis and banana peel. Furthermore, nanometric fibers commonly used in nanotechnology applications and silver nanoparticles useful in therapeutic cancer treatments, can be produced from banana pseudostems. The review aims to demonstrate the contribution of the recovery of banana production waste-loss towards a circular economy that would boost the economy of Latin America and many other countries of emerging economies.

A review on the fruit components affecting uric acid level and their underlying mechanisms

Uric acid (UA) is produced in the liver and excreted through the kidneys and intestines. If UA is overproduced or its excretion reduces, the concentration of UA increases, leading to hyperuricemia and gout. The high concentration of UA is also related to cardiovascular disease, hypertension, obesity, and other diseases. Fruits are healthy foods. However, fruits contain fructose and small amounts of purine, and the product of their metabolism is UA. Therefore, theoretically, eating fruits will increase the concentration of serum UA. Fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In addition to the UA synthesized by fructose and purine metabolism, the mechanisms by which other components affect the concentration of serum UA can be summarized as follows: (a) inhibiting xanthine oxidase; (b) reducing reabsorption of UA; and (c) improving the excretion of UA. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations, and explained their mechanisms for the first time, which references for patients with hyperuricemia to take fruits. PRACTICAL APPLICATIONS: With the rising prevalence, hyperuricemia and gout have become public health problems that endanger our daily life. The key to the treatment of hyperuricemia is to control the level of serum UA within the normal range. Fruits are healthy foods. However, fruit components are numerous, and their effects on serum UA are complex. According to the current research, fructose, purine, polyphenols, vitamin C, dietary fiber, and minerals present in fruits influence serum UA concentrations. In this review, we comprehensively discussed the fruit components that affect serum UA concentrations. We also explained their mechanisms, which references for patients with hyperuricemia to take fruits.

Valorization of Agri-Food Wastes as Sustainable Eco-Materials for Wastewater Treatment: Current State and New Perspectives

The paper addresses environmental protection by valorizing an important agri-food waste category, namely fruit and vegetables with focusing on the main characteristics regarding consumption, waste quantities, and ways for valorizing these materials. Thus, vast research was undertaken in order to emphasize the main commodities and their potential application as adsorbents for organic and inorganic pollutants. The main methods or treatment techniques applied for the valorization of eco-materials as adsorbents were presented and the principal efficiency results were indicated. The advantages and disadvantages of using these eco-materials as adsorbents in wastewater treatment were revealed and future recommendations were established. According to the international statistics, the most purchased and consumed five commodities were studied regarding waste generations as potential conversion into eco-materials with an adsorbent role for water pollutants. Thus, the performances for adsorbents based on fruit wastes (such as citrus, banana, apples, grapes, mango) and vegetable wastes (such as potatoes, tomatoes, cabbage, carrots, cauliflower, and/or broccoli) were studied and highlighted in this research.