Bioactive, antioxidant, industrial, and nutraceutical applications of banana peel

ABSTRACT People usually waste or discard the numerous benefits of banana peel due to a lack of awareness. Banana peel is a rich source of many bioactive compounds like carotenoids, biogenic amines, polyphenols, phytosterols, and antioxidants. It also contains minerals like iron, calcium, sodium, phosphorus, magnesium, and good levels of dietary fiber. The use of antioxidants present in banana peels can help reduce the risk of diseases like cancer. Antioxidants play a crucial role in the removal of toxins from the human body. One complete banana comprises about 30–40% peel, and the rest is the pulp portion. Banana peels are used in a wide range of industries like cosmetics, medicine, food processing, beverages, textiles, energy resources, paper manufacture, bio-absorbents, biofuel production, and the agricultural sector. An epic transformation in different industrial sectors can be seen because of the versatile nature of banana peel. In agricultural sectors, banana peel can be used as fertilizer to enhance the soil's physical properties, crop quality, and yield due to potassium. Even fiber-rich banana peels can be used to treat constipation problems. Banana peel carries anti-inflammatory properties that can be used in daily life as a first-aid at home to control, reduce, and cure inflammation and infections. Banana is commonly available in our homes, and thus it can be known as a zero-budget organic cosmetic product. Industrial products like paper, fiber, and textiles can be manufactured from banana peels.


Introduction
The banana crop belongs to the Musaceae family, genus Musa, which has about 70-75 species.Simmonds and Shepherds have given a modern system of classification based on chromosome number and ploidy of cultivars in which bananas were placed in different groups.Due to natural and artificial crossing, different ploidies have evolved from genomes A and B. There are diploid (AA, BB), triploid (AAA, AAB, ABB, BBB), and tetraploid subspecies (AAAA, AAAB, AABB, ABBB).The scientific name of the most commercially available and edible banana is Musa x paradisiaca, a complex hybrid of Musa acuminata (AA) and Musa balbisiana (BB), which are of diploid nature. [1,2]The banana crop stands as the fifth largest agricultural commodity in the world trade after cereals, sugar, coffee, and cocoa. [3]India is the leading producer of bananas in the world, with an annual output of about 3,30,62,000 metric tons in 2021.About 60% of banana biomass is wasted from post-harvest operations like transporting, marketing, and lack of storage systems. [4]The banana crop is considered a golden treasure of nature.This is because every part of the banana crop, like the leaf, pseudostem, flowers, fruit, and peel, is effectively used.Banana stem is scientifically known as "pseudo stem" and is used for making fiber.This fiber can be used in different industries like textiles, paper, pulp, biodegradable sanitary pads, automobiles, aerospace, and construction.Banana fiber has the best flexibility, durability, hardness, and compactness.In the Philippines, a single-use plastic has been made from banana fiber, which is biodegradable. [5]Banana leaf has had greater importance since ancient India.It is believed that eating banana leaves during festivals is very auspicious and healthy.Both the leaf and pseudo-stem of banana are used in paper manufacturing, textiles, packing, automobiles (especially interior design in cars is done by this banana fiber), and construction as fiber that replaces plastic [6], some of which are shown in Figure 1.
Flower bracts of bananas were used as coloring agents because they were rich sources of many nutritional compounds and medicinal properties.Generally, in South India, banana flowers were used for cooking curries, chutneys, and even sweet dishes. [7]Banana flowers are scientifically known as banana blossoms or banana hearts.Generally, banana fruit can be consumed as a fresh fruit, in banana shakes, or even added to cookie and cake preparations, but green-stage banana has gained popularity by making banana chips.Based on the popular fruits in the region, fruit flakes were prepared from different fruits.Specific varieties like Kothiya, Alpan, Batisha, and G-9 banana flakes were prepared. [8]anana flakes were liked by all age groups because of their tasty, crispy, and crunchy nature, and at the same time, they are easy to cook (using hot milk only; no added sugar).[11][12][13][14] The banana peel also contains polyunsaturated fatty acids (linoleic acid and -linolenic acid).It has pharmaceutical active compounds with antioxidant, anti-microbial, and anti-cancer properties.It is rich in anti-nutritional compounds such as glycosides, alkaloids, oxalates, and phytate. [15]There are 18 different types of amino acids present in banana peels at different concentrations (leucine, lysine, isoleucine, phenylalanine, norleucine, tryptophan, valine, methionine, proline, arginine, tyrosine, histidine, cystine, alanine, glutamic acid, glycine, threonine, serine, and aspartic acid).Based on banana peel color, maturity indices were estimated, and at the right stage for the right purpose based on the market distance, harvesting was done.Oxalates were present in banana peel.In the human body, when banana peels were consumed, chelating agents were formed by the combination of calcium ions with oxalates, which ultimately prevented injuries at the tissue and blood levels. [16]ilization of banana peels in food processing and beverage industries About 114.08 million metric tons of banana peels were generated as waste around the world.These wastes include natural fiber, hemicellulose, and cellulose from which bioplastics, biofuels, activated carbon, and budget-friendly filters for wastewater treatment can be manufactured. [4]In the good old days, banana peel was used as bio-fertilizer for the cultivation of crops, but later, due to an increasing population, farmers shifted to chemical fertilizers.Now again, it is valued as a treasure treasure, its importance is known, and many research works are being done on it.Many food and beverage products can be prepared from banana peels (Table 1).The nutritional value of these foods is high, providing antioxidants and boosting the immune system.Tea made from banana peels reduces weight loss. [25]Ferulic acid is a precursor of vanillin.Between lignin and carbohydrates (cellulose and hemicellulose), ferulic acid provides cohesiveness.Ferulic acid extracted from banana peels is generally used as a flavoring and aroma-enhancing agent in the food industry.Thereby, it can be used in the preparation of cookies, cakes, bread, ice cream, and bio-vanillin products. [17]Even banana peel powder was used as a flavoring agent in the food processing industry.Banana peels are used in the production of enzymes like amylase and cellulase.Amylase plays a crucial role in the hydrolyzing of complex compounds (starch) into Table 1.Effective utilization of banana peels in food processing and beverage industry.

Name of product
Variety Purpose Reference Vanillin was used as an flavoring ingredient.

Local banana
Enterobacter hormaechei was used to extract ferulic acid from banana peels convert into bio-vanillin.
Saeed et al. [17] Production of amylase, cellulase Used in food processing, textile industry & commercially amylase used as substrate Bacillus subtilis and Bacillus diastaticus.
Rana et al. [18] Chicken sausage Saba variety (genome BBB) Increase dietary fibre content, water holding capacity, and decrease fat content in the sausage Zaini et al. [19]

Jelly
Musa acuminata × Musa balbisiana 'Pisang Awak' This variety banana peel was a good source of pectin, improves firmness of jelly.
Radzi. [20]llow noodles (saba is local name of banana in Philippines) These noodles balance the nutritional levels in human body.Ramli et al. [21]

Banana peel biscuits
Local Banana peels + wheat flour Antioxidant and total phenolic content without affecting physical and nutritional properties Shafi et al. [22] Banana peel flakes Kothiya, Alpan, Batisha & G-9 Minimum browning, crispness, can be eaten as snacks, breakfast (banana flakes + milk) by all age group people Ahmad et al. [8] Instant soup mix (ISM) from banana peel Nendran 3 months shelf life, cheap, healthy, easy to cook in busy morning Dhake et al. [23] Ready to cook (RTC) curry mix from banana peel Nendran Healthy, easy to cook in busy morning Dhake et al. [23] Sauce from banana peel Nendran Healthy, easy to cook in busy morning Dhake et al. [23] Formulation of yogurt with banana peel Total phenol content increases Kabir et al. [24] simpler units (glucose) in the food, beverage, and baking industries.Thereby, amylase is used in the preparation of cakes, cookies, beer, juice, and digestive syrups. [26]It has been proven that banana peels are a good source of cellulase.The function of cellulase is the hydrolysis of cellulose present in the cell wall of all organisms by synergistic action, and so it acts as an a biocatalyst.These bio-catalysts are used in the pharmaceutical industry, textiles, bio-polishing, softening of garments, removal of dye from textiles, brewing, fermentation processes, and paper manufacture. [27]Banana peels act as a substrate for the production of amylase and cellulase. [18]eat, chicken sausage, and fish products' softness was increased by the use of banana peel or its powder sprinkled on them.As a result, it increases the dietary fiber, brightens the color, increases the water holding capacity, softens the texture, and decreases the fat content in the meat sausages. [19]Under specific conditions, a hybrid variety (Musa acuminata and Musa balbisiana) of banana was cultivated for the extraction of pectin from peels.It is used to prepare jelly, give it jelly a body and texture, give it firmness, and hold it in a shape. [20]A hybrid variety was cultivated from 3n x Musa balbisiana, and its peel powder was utilized for the preparation of yellow noodles.Prepared noodles were compared with normal noodles.The pH was higher than in normal noodles, with a bright yellow color, a length of more than 15 cm, and a thickness of 1.9-3 mm, but the structure of the noodles was weaker than normal ones.The yellow noodles were healthy and nutritious. [21]Baking products like cookies and bread were prepared by using local banana peels along with wheat flour.Banana peels were kept in the shade or mechanically dried and converted into powder for the preparation of baked products.Prepared baked products were found to have good sensory attributes without affecting their physical or nutritional properties. [22]anana peel flakes can be consumed as morning breakfast and evening snacks.In one study, banana peel flakes were found to be more nutritious than banana flakes due to their five times higher nutritional composition than banana pulp.Pre-treated banana peels are later dried in the hot oven or tray dryer, and thus crispy banana peel flakes were successfully made.These flakes can be used to prevent diabetes and depression. [28]Nowadays, instant and processed food products are gaining popularity among people due to their easy preparation, low time consumption, and nutritious properties.Instant soup mix (ISM), ready-to-cook (RTC) curry mix, and sauce were made from banana peel.A healthy ISM prepared from the Nendran variety was packed in an a laminated pouch with a 3-month shelf life.In sensory evaluation of ISM, overall acceptance was found to be good, and RTC curry was found to be healthy and easy to cook. [23]The incorporation of banana peel in the preparation of yogurt has significantly increased the phenolic content and thereby exerted antioxidant and antidiabetic activity. [24]Table 1 shows the utilization of banana peels in the food processing and beverage industries.Banana peel extracts like flavonoids have been consumed as supplements recently.Few beverage industries have launched fizzy and soft drinks enriched with polyphenols and flavonoids as a healthy products in the market. [29]

Banana peels' effective usage in nutraceutical and medicinal industry
Banana peel is an effective whitening agent and an excellent source of nutrients for the teeth.;31] Bioactive compounds present in banana peel are used for the prevention of cancer.Cell viability of MCF-7 reduced from 91.14% to 24.7% when Nendran variety of banana peel extract concentration increased from 20 to 200 g/ml. [32]Banana peel was used for treatment of heel fissures or heel crack caused especially in female because of lack of moisture and thickening of the skin.It leads to increase in the crack level because cracks create space for microbial attack and cause infection of the foot which may increase swell.So, a gel is prepared by fusion of banana peel extract with carboxyl methyl cellulose.This gel is very effective than other chemical ointments, and is eco-friendly. [33]Wound on skin is prevented with banana peel, which helps to recover soon and is eco-friendly in nature. [34]Mosquito and insect bites lead to scratch, so endocarp of banana peel should be applied immediately before ointment use; it will be quite effective and simultaneously relieves inflammation and itching. [35]

Banana peels' effective usage in cosmetic industry
Antioxidant lotion was made from banana peel (yellow-colored peels are rich in flavonoids and phenolics) and watermelon rind (rich in citrulline).Banana peel and watermelon rind components are hydrophilic (producing an attracting force on water molecules), which forms a base for the lotion.Free radicals cause damage and inflammation of cells, increase the risk of UV damage, and contribute to the development of skin cancer, so all these problems can be controlled and cured by this lotion.Lotion is soft, smooth, non-sticky, and works at the cellular level.The pH of the lotion was between 5.0 and 5.5, within the pH range of the human skin acid mantle (4.5-6.5);therefore, the lotion will not harm the skin acid mantle layer. [36]Moisturizer was manufactured by using banana peels, and due to its organic nature, no side effects on human skin were reported.It was an oil-in-water type of emulsion with 4-5 months of shelf life. [37]This moisturizer prepared from banana peels (Kepok) was very effective in preventing xerosis (skin dryness).Herbal face packs and masks were prepared by using banana peel powders or directly peeling them (see Table 2).In the herbal face pack, other organic products were added to enhance the smoothness and softness of the face.The face pack was affordable, had no side effects, and was eco-friendly. [42]A gel face mask of banana peel (Ambon variety) was found easy to peel off.It is a rich source of vitamin B6, sugars, proteins, phosphorus, vitamin C, saponins, and tannins.This mask helped to reduce fine lines and wrinkles and glow the skin. [43]anana peel-off gel mask was made in Indonesia with the Kepok variety and is a rich source of antioxidants. [41]In Sugihmanik Village, to increase natural resource usage, a shampoo was prepared from the Kepok variety of banana peel.Using the conventional maceration method, the extraction of bioactive compounds was done.Antioxidants shield the scalp from UV radiation and free radicals, so scalp health can be maintained.Banana peels have the potential to be used as a raw material for antihair-loss shampoos since flavonoids stimulate and repair damaged hair structures. [39]

Banana peels' effective usage in other industries
Banana peel extracts were used as biosorbents because they a rich rich sources of functional groups like hydroxyl groups.Biosorbent is generally used for the removal of pollutants like heavy metals (lead, Cd +2 ) from polluted water bodies. [44,45]Heavy metal percentages were  [36] Moisturizer Flavonoids, alkaloids, tannins/polyphenols saponins, and triterpenoids

Antioxidant, sun protection ability
Maintain skin health, protects from UV radiation, reduce the aging effect Cream samples contain antioxidant, activities level was above 80%, the sun protection factor was also above 15 Adeel et al. [38] Shampoo Antioxidant, flavonoids Protect the scalp from attacks by free radicals, stimulate new hair growth Liquid texture and soft texture Broto et al. [39] Scrub and mask Vitamins B6 and C12 Increase collagen and elastin, cleanse the skin, and brighten up Smell, texture, color, with good overall acceptance Pilus et al. [40] Banana peels peel off gel mask Flavonoids Protect skin from free radicals Brownish colour, with good smell and storage period was 12 weeks Agustina et al. [41] found to be higher in water bodies due to the release of waste water directly from pesticide and textile industries.Banana peel is an excellent source of Cd 2+ ions, so hydro-chars were made from it to remove heavy metals from aqueous bodies. [46]Even strontium (II) was used as a bio-sorbent to remove heavy metals from waste water released from the cosmetic, textile, and paper industries. [47]A particular bio-sorbent was used by pesticide industries, "Banana Peel Activated Carbon (BPAC)," as a metal ion adsorbent like copper and chromium [48], as shown in Table 3. Yusuf et al. [46] Feldspar-banana peel composite adsorbent for efficient crude oil removal from solution Bio-sorbent for oilspill Feldspar-banana peel biochar composite (FBPC) as this increases the hydrophobicity Dawodu et al. [49] Electricity generation from banana peels in an alkaline fuel cell with a Cu2O-Cu modified activated carbon cathode Electricity generated Electricity generated with activated carbon doped Cu 2 O-Cu composite used as a catalyst Liu et al. [50] High adsorptive potential of calcined magnetic biochar derived from banana peels for Cu2+, Hg2+, and Zn2+ ions removal in single and ternary systems Magnetic biochar derived from banana peels Act as sustainable precursor for production biochar.Calcined magnetic biochar has high adsorption efficiency with quick and easy separation.
Oladipo et al. [51] Adsorptive decontamination of rhodamine-B from water using banana peel powder: a biosorbent.Use of artificial neural network for modeling and prediction of reactive red dye removal from wastewater using banana peels bio-sorbent Potentiality of banana peel for removal of Congo red dye from aqueous solution: isotherm, kinetics and thermodynamics studies Dye bio-sorption 81% adsorbed, economical and effective in removal rhodamine-B from polluted water.
Inexpensive bio-sorbent, removed dye from polluted water.

Removed Congo red dye from aqueous solution
Singh et al. [52] Kamar et al. [53] Mondal et al. [54] Powdered banana peel in calcined halloysite replacement on the setting times and engineering properties on the geopolymer binders Geo-polymer binding Eco-friendly, minimize the environmental impact of Na/K-silicate hardener manufacture.
Nemaleu et al. [55] The use of banana peels as raw materials of bio-alcohol production Bio-Ethanol Production from Effective utilization organic waste, alternative energy source regeneration, Rich source of dopamine and gallocatechin, eco-friendly Munfarida et al. [56] Khandaker et al. [57] Ogunlade et al. [58] A review on multiple uses of banana peel.Papers manufacturing Wood exploitation reduced Prashanthi et al. [35] Mechanical properties of edible film from Tanduk Banana (Musa corniculata Rumph) peels for food packaging Bio-degradable films Eco-friendly, no preservative, kept product fresh, no contamination.
Ningtyas et al. [59] Preparation of nano-fertilizer blend from banana peels Nano bio-stimulant fertilizers were manufactured Decreases the quantity of fertilizer application for cultivated crops Hussein et al. [60] Pectin based banana peel extract as a stabilizing agent in zinc oxide nanoparticles synthesis Used as stabilizing agent for zinc oxide nanoparticles synthesis Had a promising antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi Dmochowska et al. [61] Transportation of crude oil and its products across the world is a difficult process, as oil spill occurs.Eventually, oil spill leads to crude oil wastage and causes damage to environment and so bio-sorbent is used.A new compound, feldspar-banana peel biochar composite (FBPC), which increases the hydrophobicity, was used as oil spill bio-sorbent.This combination was manufactured by natural and inorganic compounds. [49]Biomass residues (contains chemical energy) like banana peels and groundnut shells were used to generate usable energy like electricity.When activated carbon is doped with Cu 2 O-Cu along with certain banana peel extracts, electricity is generated.In geopolymer industry, huge amount of energy is required to melt sodium or potassium silicates.So, the geopolymer energy efficiency and sustainability are increasing more day-by-day and simultaneously ecological damages were made.An eco-friendly substituting compound was made from banana peel which would further minimize the environmental impact of Na/K-silicate hardener manufacture. [55]A significant impact was occurring on environmental assets like depletion of petroleum.Research was conducted on creating alternative energy sources.Bio-fuel created from wastage of fruits and vegetable peels was successful.Biofuel has ecofriendly nature and controls the depletion process of renewable sources in the environment.From organic wastage, even bio-alcohol was also made.[58] Papers were manufactured from banana peels, and thus wood exploitation can be reduced.About 2-3% of additives like essential oils (cinnamon oil, lemon oil, clove oil, and lime oil) were used to enhance aroma and preservation quality of the papers. [35]A specific banana peel variety known as Tanduk Banana (Musa corniculata Rumph) was used in packaging industry.The film packaging material kept the product fresh, controlled contamination, was ecofriendly, and no preservatives were added to those films. [59]Nano bio-stimulant fertilizers were manufactured from banana peel extracts in agriculture sector.It decreases the quantity of fertilizer application for cultivated crops, which was the best commercial product of nanotechnology.It was proved that quality of fertilizer was increased by using banana peels in the manufacturing of nanofertilizers. [60]It is used as a stabilizing agent for zinc oxide nanoparticles synthesis. [61]nana peel extractions and their findings Due to the different phytochemical types, a unique or modified extraction method needs to change.Purification percentage and analysis of bioactive chemicals from plant material or byproduct depend on sample and extraction methods.Three categories of phytochemical extraction methods, traditional, innovative, or a mix of these two methods, can be used. [62]Like temperature was found to have significant impact on extraction of polyphenol content and antioxidant capacity from orange peels, banana peel extract reduces oxidative stress, and thus they are suitable for application in biopharmaceuticals; their potential enhances UV protection in creams. [63]The yield from the conventional Soxhlet method was higher, but the quality was worse.In terms of extraction time and quality, microwave-assisted extraction (MAE) was preferred.With less energy consumption and extraction time, a good quality banana peel extract was found in ultrasound-assisted extraction method (modified Soxhlet extraction method).Subcritical water extraction (SWE) was used to separate pectin from banana peels in a sustainable and ecofriendly manner, but high temperatures made it unfit for thermolabile compounds. [64]The methods that can be used to extract some important components of banana peels are shown in Table 4.

Conclusion
Banana peel extract was used efficiently in the food processing, beverage, agriculture, and pharmacy industries as a biosorbent for dye removal.Different varieties of banana peels have various bioactive compounds at different concentration levels.According to the industry's requirements and purpose, banana peels are used.In ancient times, banana peel uses were limited.It was used as cattle feed, as peel curry, especially in Kerala and Tamil Nadu states, and as organic fertilizer.But nowadays, banana peels are used in different industries, like the textile industry, for fiber purposes.Even today, it is used in the automobile industry, especially to design the interior model for new cars, because of fiber usage (low- Hernández-Carranza et al. [67] (Continued) Microwave-assisted extraction method results were good, as it shows close value between predicted (12.8%) and actual yield (14.2%) of pectin Rivadeneira et al. [68] Extraction Chaudhry et al. [69] Formulation and evaluation of novel herbal toothpaste in oral care cosmetology

Antioxidants
Followed the extraction technique of Bobby Gene Edward adapted with some modifications Extraction of propane from peel and inner peel, to evaluate phytoconstituents for oral care tooth whitening formulation.
Banana inner peel extract toothpaste is stronger and stable effect on teeth.It may also be used as a nutricosmetic, has own fruity scent so minimizes the negative effects of chemical and synthetic flavouring agents Salman et al. [30] Gene.[70]   Antioxidant potential of peel extracts of banana varieties (Musa sapientum)

Antioxidants, polyphenol, flavonoids
Slightly modified spectrophotometric method Brand-Williams To examine and compare the types of phytochemicals present, in vitro antioxidant and antibacterial activity in nine local varieties of banana peel extracts.
Rasthali had higher ABTS scavenging activity, whereas Poovan banana had more flavonoids and lipid peroxidation inhibitory activity BrandWilliams et al. [71] Baskar et al. [72] cost fiber).In the paper and pulp manufacturing industry, a unique quality paper with a good aroma is produced.Additives were added in the packaging industry so that good aroma and biodegradable nature increased the sale in the market.Banana peels are also used for making biodegradable masks in the medicinal industry.This review paper fulfills the goals of sustainable development (SDGs), which bring transformation to our world.It fulfills goal no.2: zero hunger because different types of processed food items are prepared by using banana peel, and its extract-based biodegradable films are used on the fruits and vegetables so that the product shelf life increases.It also fulfills goal no.3: it is good for health and well-being because banana peels are rich in antioxidants; it has many antiinflammatory and antibacterial properties that are used to cure skin wounds and cancer.It also fulfills goal no.4: clean water and sanitation because it is used as an a bio-absorbent which means it cleans or removes especially heavy metals from polluted waterbodies from different industries like pesticide industries and dye industries, where the used water is directly released into water bodies.
Fruit and Vegetable Waste by Using Saccharomyces cerevisiae Comparative study of chemical composition and evaluation of the In-Vitro antioxidant capacity of unripe and ripe banana species (Musa sapientum) biowastes Bio-alcohol Created alternative natural resources bioalcohol.

Table 2 .
Bioactive compounds in banana peels used in cosmetic industry.

Table 3 .
Effective utilization of banana peels in different industries.

Table 4 .
Recent studies done on banana bioactive extraction methods and their findings.