Sage Journals: Discover world-class research

Abstract

The cashew apple with high nutritional and bioactive profile have always been underutilized. Cashew apple juice is a dense source of essential nutrients, including vitamin C, B-complex vitamins, calcium, potassium, magnesium, and a diverse array of antioxidants such as carotenoids and polyphenols. The phytochemical constituents of cashew apple juice, particularly its polyphenolic compounds like anacardic acids, flavonoids, and tannins, have demonstrated significant anti-inflammatory, antibacterial, antiviral, and anticancer properties. These bioactivities suggest promising applications in the development of natural therapeutic agents, functional foods, and nutraceuticals that can support immune function and combat chronic diseases. Besides, its high content of fermentable sugars mainly glucose, fructose, and sucrose make it suitable and sustainable substrate for bioethanol production through microbial fermentation. The present study examines the potential contribution of cashew apple juice in renewable energy generation in the form of bioethanol, medicine, and nutrition with an emphasis on its multifunctional benefits. This work reveals that cashew apple valorization embodies the circular economy's goal of decoupling growth from resource extraction, demonstrating how waste can become a cornerstone of sustainable development thus, suggesting further research on the transformation of cashew apple fruits into bioethanol and other value-added products.

Keywords

cashew apple bioethanol nutrients antioxidants cancer cells antibiotics

Introduction

Several studies have reported that agricultural waste has great applications in bioethanol production, nutrients, and healthcare sector.¹ Usually, large amounts of agricultural waste are generated during harvesting, transportation, processing, and consumption.² For instance, nut harvesting from the cashew tree (Anacardium occidentale L.) of the Anacardiaceae family produces a substantial amount of biowaste comprising nut shells and fruit remains that contribute to environmental pollution and waste disposal challenges.^3,4 Cashew, native to Brazil, is a fruit tree that thrives in tropical climate.⁵ A report shows that cashew tree was introduced to prevent the Sahara Desert from advancing and reduce soil erosion in some African countries.⁶ Cashew nuts are popularly valued and grown in different areas globally.⁷ Cashew apple production is influenced by cashew tree cultivation regions, with West Africa's Nigeria, Ivory Coast, Benin, and Ghana being the largest global producers.⁸ Cashew processing is advanced in South and Southeast Asia.⁸ Brazil and Central America have cashew industries with potential for value-added products and valorization.⁹ The southern Tanzanian areas are the primary locations for cashew growing; Mtwara and Lindi alone account for more than 87% of Tanzania's total cashew production.⁸ontributions are comparatively lower.¹⁰ Cashew is a major cash crop and the third most produced edible nut in the world after groundnuts and almond.^7,11,12 Cashew production grew from 0.29 to 2.60 million metric tons in 1961 to 2013, respectively.⁵ From 2010 to 2021, cashew production was estimated at 3 to 3.7 million metric tons.¹³ Thus, from 1961 to 2021, the global cashew nut production grew by almost 12-fold cumulatively in the 60-year period or by 20% on average per annum. This growth is attributed to different factors including improved farming techniques, expanded cultivation areas, and growing demand for cashew in developed and developing markets.⁵ Cashew is a plant with different parts, each having special qualities and application.¹⁴ Cashew is an edible seed covered with a hard shell rich in oils and nutrients.¹⁴ The cashew shell is a significant waste used to make lubricants, varnishes, and resins.¹⁵ These are complemented by cashew apple, a large, fleshy pedicel that grows from the stem of the nut.¹⁶ The cashew apple is frequently referred to as the cashew tree's false fruit which is thrown away when the nut is harvested.¹⁶ The cashew apple is yellow, orange, or red in color, juicy and is utilized to make jams, drinks, and fermented goods such as wine.¹⁷ Only nuts are processed and consumed, and the remaining cashew apple parts are discarded as waste products. After nut separation, large quantities of cashew apples are wasted, yet they can be turned into valuable commodities. Studies show that approximately 36.9 million tons of cashew apple are produced which accounts for 90% of the weight of the cashew fruit.¹⁴ When the nut is removed from cashew apple, 90–95% of the total fruit weight is typically discarded due to limited technical knowledge, high processing equipment costs, poor postharvest management, low adoption of processing technologies, and the fruit's astringent taste.¹⁸ A report indicates that 1,050,000 tons of cashew apple were produced in 2023¹⁹ revealing that large amount of cashew apple are produced as waste products during the nut separation and are discarded while some are used for animal feed.¹⁴ Thus, cashew apple serves as an abundant and eco-friendly raw material that can be efficiently processed into valuable products such as bioethanol. The production of bioethanol from cashew apple necessitates careful management of cashew apple. Still, cashew apple has a wide range of application in nutrition and medicine. Studies indicate that cashew apple is used in making juice and alcoholic drinks like cashew wine.¹⁸ Moreover, cashew apple juice is used to make nutritional and healthful dried fruit treats, jams, and syrups.¹⁸ Since cashew apple juice is rich in bioactive chemicals, it has a variety of medical uses such as anti-inflammatory and antioxidant properties provided by its high polyphenol and vitamin C content which lower inflammation and boost the immunity.⁴ Studies show that cashew apple juice extracts control blood sugar levels because it contains anti-diabetic effects.²⁰ Besides, the antibacterial qualities of cashew apple extracts render its capability to fight off bacterial illnesses, including some foodborne diseases.⁴ Given this backdrop, the review aimed to establish the potential applications of cashew apple juice in nutrition, medicine, and as a source of eco-friendly bioenergy in the form of bioethanol. Revealing the potential of cashew apple, an agricultural waste in diverse uses encourages more research towards its wide application and supports circular economy in addition to environmental conservation. Notwithstanding, cashew's widespread guarantees the availability of cashew apples that go with them which are frequently thrown away or destroyed, causing financial losses as well as environmental issues. The review's justification is to compile the body of knowledge regarding cashew apples’ juice nutritional, medicinal, and industrial potential, with an emphasis on their bioactive constituents and uses in juice production, bioethanol production, and therapeutic applications. The study attempts to demonstrate how cashew apples’ juice can be valorized, transforming what is typically seen as agricultural waste into useful resources, by combining research from many sectors. The current review pursues the potential applications of cashew apple in nutrition, medicine, and as a source of eco-friendly bioenergy in the form of bioethanol.

Phytonutrients and Phytochemicals from Cashew Apple Juice: Benefits and Challenges

Cashew apple shown in Figure 1 is a plentiful but underutilized agro-industrial waste.²¹ It contains the juice which is highly nutritious and biochemically rich feedstock which is potential for production of bioethanol, despite its little commercial use.²² Cashew apple juice potential for bioethanol production is because of its high content of fermentable sugars.²² A report indicates that cashew apple has a dry matter content of about 12.32%, while its composition varies depending on several factors.²³ Its total fiber content ranges from 3.5% to 10.85%, while its crude protein level ranges from 6.45% to 12.5%.²³ The cashew apple juice is a valuable source of fermentable sugars since its total sugar content mostly glucose ranges from 6% to 54.7%.²³ Thus, cashew apple juice is a promising and affordable feedstock for generation of bioethanol through anaerobic fermentation because of its natural sugar composition. Besides, its abundance of vitamins, minerals, dietary fibers, and bioactive substances, cashew apple juice is excellent for nutrition and medicine.¹⁸ Cashew apple juice is a rich source of essential nutrients and bioactive compounds including vitamin C, polyphenols, flavonoids, tannins, carotenoids, fructose, glucose, dietary fiber, minerals like potassium, magnesium, and calcium, and bioactive compounds like anacardic acid and alkaloids.²⁴ These nutrients and bioactive compounds together contribute to overall health and wellness, making cashew apple juice a valuable addition to any diet.²⁴ Its antioxidant and anti-inflammatory properties help protect against chronic diseases like diabetes, heart disease, and cancer.²⁵ Table 1 summarizes the composition of cashew apple juice.

Figure 1.

An Image of Cashew Apple.³⁰

Table 1.

Chemical Composition of Cashew Apple Juice.

Component	Typical range/content	Reference
Moisture (%)	58–78	²⁶
Carbohydrates (g/100 g)	9–19	²⁶
Sugars (g/100 g)	Glucose:3.5–5.0 Fructose:2.5–4.0 Sucrose: 1.5–3.0	²⁶
Dietary Fiber (g/100 g)	0.04–8.8	²⁷
Vitamin C (mg/100 g)	200–600	⁴
Vitamin A (IU/100 g)	50–150	⁴
Phenolic compounds (mg GAE/g)	1.5–3.5	²⁸
Potassium (mg/100 g)	150–250	²⁸
Calcium (mg/100 g)	20–40	²⁹
Magnesium (mg/100 g)	10–25	²⁸
Phosphorus (mg/100 g)	15–30	²⁹

Because of its diverse biochemical makeup including; high vitamin C which supports the immunity and acts as an antioxidant, presence of glucose and fructose which provides quick energy and serves as substrates for fermentation, minerals such as magnesium, zinc, and iron which are critical for metabolic and cardiovascular health, cashew apple juice exhibits a unique convergence of nutritional, therapeutic, and bioethanol benefits.^19,22

Cashew apple juice is a rich source of vital vitamins, minerals, and bioactive molecules that promote general health and wellbeing.³¹ Reports show that cashew apple juice has five times the amount of vitamin C as oranges, making it a powerful antioxidant and immune-boosting source.³² It contains high levels of vitamin A and B-complex which promote healthy skin, eyesight, and metabolism.³³ The minerals potassium, magnesium, iron, and phosphorus present in cashew apple are essential for preserving the body's electrolyte balance, muscle contraction, and oxygen transfer.¹⁸ Cashew apple juice is a fast and easily digestible energy source and is a natural provider of carbohydrates mainly fructose, glucose, and sucrose.³⁴ Studies indicate that cashew apple contains about 10.5% of reducing sugar, making it a good source of energy for human health.⁴ Still, cashew apple juice phytochemical makeup including tannins, polyphenols, flavonoids, and carotenoids offers potent antioxidant qualities that combat free radicals, lessen oxidative stress, and lower the chance of developing chronic illnesses.^9,18 Cashew apple juice have a pH range of 3.5 to 4.8, making it quite acidic which support immune function, aids in digestion and promote skin health.²³ Cashew apple juice which is rich in 61.21% dietary fibers, aids in regulating blood sugar levels, supporting heart health, promoting gut health, prevents constipation and promotes regular bowel movements.^22,23 Besides, dietary fiber is essential for lowering the risk of long-term conditions like diabetes, heart disease, and colon cancer.³⁵ Cashew apple juice is rich in bioactive molecules like tannins, flavonoids, and phenolic acids that have important therapeutic benefits.³⁶ Studies show that cashew apple juice has long been used to treat throat infections because of its potent antibacterial activity, making it useful against a variety of harmful bacteria and fungus.³⁷ Cashew apple juices’ anti-inflammatory and antioxidant properties aid in reducing inflammation and oxidative stress, the two factors that are crucial in the emergence of long-term illnesses like diabetes, cardiovascular disease, and neurological diseases.³⁸ Cashew apple juice rich in polyphenols possesses potential anti-cancer properties, potentially causing apoptosis and inhibiting tumor growth in cancer cells.³⁹ Since cashew apple juice possesses antibacterial and astringent qualities that speed up healing from cuts, burns, and skin infections, it has long been used for wound healing and skincare.³⁹ Numerous research investigations have confirmed that cashew apple juice possesses a variety of bioactive qualities with potential health advantages. Cashew apple juice has been shown to have antibacterial activity, especially against clinical isolates like Staphylococcus aureus and Streptococcus mutans, where notable inhibitory zones demonstrated potent antimicrobial effects.⁴⁰ Furthermore, the juice has demonstrated effectiveness against urinary tract bacteria that are resistant to antibiotics, such as Pseudomonas aeruginosa and Enterococcus faecalis, indicating that it may be used to treat resistant infections.⁴⁰ Phenolics, flavonoids, and tannins were found in phytochemical analyses. These compounds have antibacterial activity against a variety of bacteria, including Streptococcus pyogenes, Micrococcus luteus, and Salmonella typhimurium.⁴¹ Cashew apple juice has anti-inflammatory and wound-healing properties, which considerably reduce inflammation (ear oedema).¹⁸ An anti-inflammatory and wound-healing property, cashew apple juice significantly reduces inflammation and accelerates wound contraction.⁴² This effect is likely due to its high content of vitamin C and antioxidant phytochemicals, which help modulate inflammatory responses and promote tissue repair.⁴² Furthermore, cashew apple juice exhibits anticancer and antimutagenic potential.⁴³ As the interest in natural and plant-based therapies grows, cashew apple juice has the potential for use in cosmetic and pharmaceutical applications, opening the door to new and innovative health solutions.

Cashew apple juice has a rich nutritional content and many health benefits thus, have great potential in nutrition and medicine.¹⁸ With essential vitamins and minerals like vitamin C, calcium, potassium, and magnesium, cashew apple juice has a comprehensive nutritional importance.⁴⁴ Although their high dietary fiber content promotes intestinal health and digestion, their bioactive components such as flavonoids and polyphenols have anti-inflammatory and anti-oxidant properties which lower the risk of chronic diseases like cancer, diabetes, and heart disease.⁴⁵ From medicinal perspective, cashew apple juice has high vitamin C and tannin content which have antimicrobial qualities which help to control blood sugar, and promote wound healing.⁴⁶ Additionally, they have significant economic potential because they may be converted into juice, jam, vinegar, and alcohol, reducing waste and benefiting farmers in terms of boosting their economy.⁴⁷ The nutritional comparison of cashew apple juice and other common juice is presented in Table 2.

Table 2.

Nutritional Comparison of Cashew Apple Juice Against Other Common Fruit Juices.⁴⁸

Nutrient (per 100 mL)	Cashew apple juice	Orange juice	Apple juice	Pineapple juice
Calories (kcal)	35–45	45–50	46–50	45–50
Carbohydrates (g)	8–10 (mostly natural sugars)	10–12	11–13	11–13
Vitamin C (mg)	Very high: 200–500 mg (up to 5x orange juice)	50–60	1–2	15–25
Protein (g)	0.3	0.7	0.1	0.5
Fiber (g)	Low (mostly juice, some soluble fiber)	Low (usually minimal fiber)	Low (usually minimal fiber)	Low
Minerals (Potassium mg)	Moderate (150-200)	Moderate (180)	Moderate (100-150)	Moderate (100-130)
Antioxidants	High (rich in phenolics, flavonoids, carotenoids)	Moderate to high (flavonoids, carotenoids)	Moderate (polyphenols)	Moderate (vitamin C, bromelain)

However, cashew apple has several challenges that prevent them from being used widely, despite their nutritional and commercial potential. They are difficult to store and transport due to their extreme perishability, which causes them to decay 24 to 48 h after harvesting.⁴⁹ Additionally, some customers may find their astringent flavor and texture unattractive because of tannins and other components.⁵⁰ Their underutilization is further exacerbated by low market demand and awareness because are not as well-known or promoted as other tropical fruits. The lack of large-scale processing infrastructure in many cashew-producing countries adds additional obstacle while extraction and processing provide challenges, requiring specialized procedures to increase flavor and reduce astringency.⁵¹ Additionally, certain people may have sensitivity or allergic responses to cashew apple juice, especially because of specific bioactive components that can cause allergic actions.⁵²

Cashew apples are a rich nutritional profile and bioactive components but are frequently thrown away in the environment. However, recent studies show how promising it is to produce bioethanol, in nutrition and medicine.²² A report indicates that yeast fermentation procedures of cashew apple juice produces bioethanol that is comparable to pineapple fruit wastes with 10–12 ⁰Brix,⁵³ its high sugar content in the range 8–12 ⁰Brix fermentable sugars makes cashew apple juice attractive feedstock for production of bioethanol.⁵⁴ Furthermore, producing biofuels from cashew apple supports sustainability and lessen agricultural waste.¹⁹ A nutrient-dense fruit that is high in vitamin C more than oranges, dietary fiber, potassium, magnesium, iron, polyphenols, and flavonoids, cashew apple juice aid in digestion, immune system support, and general health in addition to producing bioethanol.⁴⁴ Thus, cashew bears promising potential for use in diverse critical fields which consequently attracts more attention and research for full realization. However, there are numerous important obstacles for the increased production of cashew apple juice. Because of their high moisture and sugar content, cashew apples spoil 24 to 48 h after harvest, making them extremely perishable. Because of quick spoiling, transport routes are limited, and urgent processing is required, which is especially difficult in remote locations with little infrastructure. Besides, there is insufficient infrastructure for extraction, fermentation, and preservation of juice on a big scale. Thus, there is a significant amount of cashew apple waste due to lack of cold chains or mobile processing facilities. Unless preservation methods like juice concentration, freezing, or drying are used, the seasonality of cashew harvesting usually once a year causes inconsistent feedstock supply, which is likely to disrupts continuous bioethanol production. Scaling initiatives are made more difficult by logistical and regulatory obstacles. Thorough clinical testing, standardization, and clearance by regulatory agencies like the Food and Drugs Administration (FDA), National Agency for Food and Drug Administration and Control (NAFDAC) are necessary for cashew apple juice used for therapeutic or nutraceutical use. However, these procedures can be expensive and time-consuming. Still, strict national and international fuel criteria, including quality control, purification, and adherence to environmental laws must be met by the ethanol produced cashew apple juice. Reliable and economical collection is hampered logistically by inadequate rural roads, a lack of cold storage, and unstable power sources, which make it difficult to coordinate supply chains from farm collection to processing centers.

Bioethanol Production from Cashew Apple Juice: Benefits and Challenges

A report reveals that the world is now shifting to sustainable and renewable energy sources, and interest for bioethanol generation from non-food biomass has grown significantly.⁵⁵ Cashew apple, a commonly accessible and underutilized agricultural waste has high sugar content, making it a suitable raw material for bioethanol production in form of bioethanol.²¹ Apple juice bears promise as a feedstock for the production of bioethanol.⁵⁶ Because it contains a lot of sugar, primarily glucose, fructose, and sucrose, cashew apple juice is a great substrate for fermentation to produce bioethanol.⁶ By acting as a renewable fuel substitute, bioethanol lessens the dependency on fossil fuels and cut down greenhouse gas emissions. In major cashew-producing countries where enormous quantities of fruit are thrown away as trash after nut harvesting, the bioethanol potential of cashew apple is particularly obvious. Producers can generate new value streams, encourage sustainable farming methods, and support rural economic growth by turning this agricultural by-product into bioethanol. It has the potential in technological developments, mainly in the expansion of alternative energy sources through the processing of its waste thus, adding value to the product.⁵⁷ Studies show that cashew apple is wasted in the environment during cashew processing although it can be processed into bioethanol, an alternative energy source.⁵⁸ Reports indicate that cashew apple juice contains high amount of fermentable sugars including glucose, fructose, and sucrose.^19,59 Studies show that cashew apple juice contains a range of 10 to 11.3 ˚Brix with a density of 1.042 g/cm³ and average pH of 3.7.¹⁹ The sugar content and pH highlight the potential of wasted cashew apples for bioethanol production. Due to their high content of fermentable sugars, cashew apples serve as an excellent feedstock for bioethanol production.¹⁹ Still, a report indicates that one kilogram of cashew apple can yield 500–600 mL of bioethanol.⁶⁰ This highlights that low amount of cashew apple can yield substantial amount of bioethanol. Studies reveal that bioethanol with alcohol content of 7.5% was obtained after 5 days fermentation of cashew apple juice, resulting into 46.7% after distillation at 94.5 °C and 95% following re-distillation at 78.2 °C.⁶⁰ Besides, a study indicates that cashew apple juice treated with Saccharomyces cerevisiae yielded bioethanol of 75% after distillation.⁶ Bioethanol production from cashew apple can be done using either fresh or dried cashew apples.⁵⁷ However, studies show that fresh cashew apples yield higher concentration of bioethanol, 9.2% v/v than dried cashew apples, 7% v/v.⁵⁷ This is due to addition of water in dried cashew apple powder, causing dilution of total soluble solids.

Cashew apples offer numerous benefits as raw materials for bioethanol production. Cashew apples are plentifully available in tropical regions where cashew tree is cultivated, often posing a challenge when disposed into the environment.¹⁹ Cashew apples, which are leftovers from cashew nuts processing offer a cost-effective option when used as raw materials for generation of bioethanol. Purchases expenses are much cheaper because cashew apples have limited market value because they are usually regarded as residues since are not the main focus of cashew farming.¹⁹ Therefore, because of their affordability, cashew apples are a desirable substitute for more costly feedstocks like corn or sugarcane that have usually a competition with food supply. The cost-effectiveness of bioethanol production from cashew apple juice when compared to conventional sources like sugarcane and corn is influenced by several factors. Because cashew apple juice doesn't require a lot of pre-processing and is high in fermentable sugars, it can be produced at a lower cost. Its raw material costs are also frequently low or even free because it is a by-product of the cashew industry. More importantly, sugarcane and corn are globally significant food sources and therefore directly compete with the food supply chain, unlike cashew apple fruits. However, financial limitations might prevent its widespread use. However, using cashew apples to produce bioethanol contributes to environmental and economic sustainability by adding value to an otherwise underutilized resource while reducing waste.⁶¹ Furthermore, using cashew apples promotes sustainability by minimizing greenhouse gases emissions, encouraging circular economy, and reducing agricultural waste in comparison to fossil fuels.⁶¹ A circular economy seeks to eradicate waste, maintain the circulation of materials, and restore natural ecosystems. Cashew apples, typically thrown away despite their nutritional benefits, can be converted into products such as bioethanol, nutrients, and medicine.⁹ This repurposing minimizes waste and promotes sustainable economic growth, embodying the fundamental principles of circular economy. Moreover, the high sugar content ranging from 50–200 g/L of glucose and fructose, vitamin C, minerals and amino acids in cashew apples allows for direct fermentation into bioethanol, eliminating the need for complex pre-processing thus, improving production effectiveness.¹⁹ Thus, bioethanol from cashew apple juice offers numerous applications such as fuel for electric power, in fuel cells, and in energy cogeneration systems.⁶² Bioethanol from cashew apple provides several environmental benefits compared to fossil fuels as it burns cleaner, releases significantly less carbon dioxide (CO₂), sulphur oxides (SO_x), and nitrogen oxides (NO_x), which contributes to a decrease in greenhouse gases emissions.⁶³ Furthermore, bioethanol is non-toxic and biodegradable, reducing the possibility of environmental contamination from fuel leaks and oil spills linked to fossil fuels.⁶⁴ Cashew-based bioethanol production helps to reduce organic waste pollution caused by cashew waste.¹⁹ Since cashew tree bears fruit every year, bioethanol from cashew apples is a renewable and sustainable energy source that can replace fossil fuels, the limited and rapidly depleting source of energy.⁶⁵ Reports show that during machinery operation, bioethanol consumption is low compared to gasoline for instance; a generator operating for 60 min consumes 12% of bioethanol and 40% gasoline compared to of gasoline it could consume when using gasoline alone.⁶ Because of such environmental advantages, bioethanol is environmentally responsive and sustainable substitute for fossil fuels.

Despite its enormous potential, there are several challenges in producing bioethanol from cashew apples. Reports show that preserving cashew apples is a significant challenge because they decay easily due to high moisture content which ranges from 85%-90% thus, require quick processing or preservation using efficient techniques.¹⁹ Still, cashew apple contains tannin, a polyphenol compound that inhibits bioethanol production by interfering with the fermentation process of microorganisms such as yeast which are essential for converting sugars into bioethanol.⁵⁹ Due to this cost, pre-treatment methods like enzymatic treatment and activated carbon adsorption are required to neutralize the inhibitory compounds, ensuring efficient bioethanol production. However, storage facilities and preservation methods such as drying or ensiling can help to maintain the quality of cashew apple over time.⁴⁴ Besides, managing cashew apples supply chain for maintaining efficient bioethanol production is a challenge.²¹ Because of geographical and seasonal fluctuations in the availability, it is challenging to guarantee a steady and adequate supply of cashew apples.⁶⁶ Cashew apples’ high perishability, ineffective infrastructure for collection and processing, and small economies of scale can raise operating and logistical expenses.⁶⁷ However, to address this issue and ensure a consistent supply of feedstock, collaboration among cashew processing businesses, marketplaces, and agricultural sectors is necessary. A report indicates that cashew apples for bioethanol production should be collected within 3 days after cashew nut separation.³¹ Still, the infrastructure required for large-scale bioethanol production is lacking in many cashew-producing developing regions, which may limit the initiative's scalability.⁶⁸ Assuring environmental sustainability and optimizing resource efficiency also depend on the appropriate processing and use of fermentation by-products such as cashew apple pulp.⁶⁸

Conclusion

Cashew apple juice is rich in vital nutrients including vitamins, minerals, dietary fibers, and bioactive molecules that altogether have a variety of pharmacological characteristics. Frequent cashew apple juice consumption can help to avoid diseases including pathogenic infections and chronic illnesses as well as treat nutrient deficiencies. The cashew apple juice is used to make bioethanol. This aligns with the Sustainable Development Goals of the UN since it lessens carbon emissions and dependency on fossil resources which adds to sustainable energy sources. Besides, cashew apple juice offers nutritional and medicinal benefits in addition to supporting circular economy. Thus, cashew apples have a lot of promise as a source of bioethanol and nutraceuticals, providing financial and health advantages. More focused research is recommended on the wide availability of cashew apple in different critical fields, the key idea and an approach to environmental waste management.

Materials and Methods

The current review analysed a variety of scholarly literature from Google Scholar database focusing on the uses of cashew apple through a structured sampling and bench review methodology in 5 stages including the introduction, phytonutrients and phytochemicals from cashew apple juice: benefits and challenges, bioethanol production from cashew apple juice: benefits and challenges, conclusion, and materials and methods. The study undertook an in-depth analysis of the potential of cashew apple juice in bioethanol generation, a clean energy source, aligning with Sustainable Development Goals (SDGs), particularly SDG7, which focuses on ensuring universal access to affordable, reliable, and modern energy by 2030.⁶⁹ Besides, the application of cashew apple juice in nutrition and medicine has been examined. The roadmap emphasizes how cashew apple-derived products can address environmental challenges, promote circular economy, and enhance sustainable production and utilization of bioethanol. The review used the keywords including cashew apple, cashew apple juice, bioethanol, nutrients, antioxidants, cancer cells, antibiotics to search relevant information for the study. From the search using the keywords, 102 articles were obtained but only 69 articles were found relevant to the study thus, were selected for inclusion.

Footnotes

Acknowledgements

Authors are grateful to Mkwawa University College of Education for materials support.

ORCID iDs

Lewis Atugonza Mtashobya

Shedrack Thomas Mgeni

Kamuhabwa Emmanuel

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data Availability Statement

All data used for the research described are presented in the article.

References

Reddy

Kumar

Rao

, et al. Waste to wealth generation: innovative methodologies in resource utilization and minimization in circular economy. EDP Sci. 2023;453:01035.

Obi

Ugwuishiwu

Nwakaire

. Agricultural waste concept, generation, utilization and management. Niger J Technol. 2016;35(4):957-964.

Mubofu

. From cashew nut shell wastes to high value chemicals. Pure Appl Chem. 2016;88(1-2):17-27.

Reina

LJC

Durán-Aranguren

Forero-Rojas

, et al. Chemical composition and bioactive compounds of cashew (Anacardium occidentale) apple juice and bagasse from Colombian varieties. Heliyon. 2022;8(5).

Olubode

Joseph-Adekunle

Hammed

Olaiya

. Evaluation of production practices and yield enhancing techniques on productivity of cashew (Anacardium occidentale L.). Fruits. 2018;73(2):75-100.

Gnagne

AAGB

Soro

Ouattara

Koui

Koffi

. A literature review of cashew apple processing. AJFAND. 2023;23(2):22452-22469.

Monteiro

Catarino

Batista

Indjai

Duarte

Romeiras

. Cashew as a high agricultural commodity in West Africa: insights towards sustainable production in Guinea-Bissau. Sustainability. 2017;9(9):1666.

Babatunde

Adeigbe

Sobowale

Muyiwa

Balogun

. Cashew production and breeding in 5 West African countries. JSRR. 2023;29(5):28-39.

Da Silva

De Brito

Ferreira

SRS

. Biorefinery of cashew by-products: recovery of value-added compounds. Food Bioproc Tech. 2023;16(5):944-960.

10.

Mmbughu

Katundu

Mrimi

. Determinants of smallholder Farmers’ participation in cashew nut production in Lindi and Mtwara Regions, Tanzania. JCBS. 2024;8(2):1-19.

11.

Ćwieląg-Drabek

Nieć-Leśniak

Białek-Dratwa

, et al. Evaluation of cadmium, lead, chromium, and nickel content in Various types of nuts: almonds, cashews, hazelnuts, peanuts, and walnuts–health risk of Polish consumers. Biol Trace Elem Res. 2024:1-18.

12.

Kolliesuah

Saysay

Zinnah

Freeman

Chinenye

. Trend analysis of production, consumption and export of cashew crop in West Africa. Afr Crop Sci J. 2020;28(s1):187-202.

13.

FAO V. FAOSTAT: crops and livestock products. Food Agric Organ United Nations [Internet]. 2023.

14.

Van Walraven

Stark

. From food waste to functional component: cashew apple pomace. Crit Rev Food Sci Nutr. 2024;64(20):7101-7117.

15.

Lubi

Thachil

. Cashew nut shell liquid (CNSL)-a versatile monomer for polymer synthesis. Des Monomers Polym. 2000;3(2):123-153.

16.

Tamiello-Rosa

Cantu-Jungles

Iacomini

Cordeiro

. Pectins from cashew apple fruit (Anacardium occidentale): extraction and chemical characterization. Carbohydr Res. 2019;483:107752.

17.

Gomes

Freitas

Watanabe

Guerreiro

MEF

da Rocha Sousa

Ferreira

ACS

. Dehydrated cashew apple meal in the feeding of growing rabbits. Semin, Ciênc Agrár. 2018;39(2):757-770.

18.

Akyereko

Yeboah

Wireko-Manu

Alemawor

Mills-Robertson

Odoom

. Nutritional value and health benefits of cashew apple. JSFA Rep. 2023;3(3):110-118.

19.

N’guessan

Bedikou

Abouo

, et al. Waste cashew apple (Anacardium occidentale) as feedstock for simultaneous production of two main ecofriendly fuels. JPEE. 2023;11(8):16-31.

20.

Dosso

Niamke

Soro

Ouattara

PGH

Coulibaly

. Autoregulatory glycemic activity of the aqueous extract of cashew apple cake (Anacardium occidentale L.). JPP. 2021;10(3):56-62.

21.

Antony

Kunhiraman

Abdulhameed

. Bioprocessing with cashew apple and its by-products. Valorisation Agro-Ind Residues–Volume II: Non-Biol Approaches. 2020;2:83-106.

22.

Adjou

Gbaguidi

Dègnon

Dahouenon-Ahoussi

Mohamed

Sohounhloue

. Potential of cashew apples as valuable raw materials in food industry and biotechnology in Africa: a review. J Elixir Biosci. 2017;108:47644-47647.

23.

Pascal

ADC

Virginie

Diane

BFT

, et al. Nutritional profile and chemical composition of juices of two cashew apple’s varieties of Benin. J Chem. 2018;4(4):91-96.

24.

Salehi

Gültekin-Özgüven

Kırkın

, et al. Anacardium plants: chemical, nutritional composition and biotechnological applications. Biomolecules. 2019;9(9):465.

25.

Siracusa

Fusco

Peritore

, et al. The antioxidant and anti-inflammatory properties of Anacardium occidentale L. cashew nuts in a mouse model of colitis. Nutrients. 2020;12(3):834.

26.

Nurerk

Junden

. Product development based sensory evaluation and physicochemical characterization of cashew apple bagasse jam and technology transfer to community. Trends Sci. 2021;18(22):454-454.

27.

Batista

Alves

dos Santos Lima

, et al. Beneficial effects of consumption of acerola, cashew or guava processing by-products on intestinal health and lipid metabolism in dyslipidaemic female Wistar rats. Br J Nutr. 2018;119(1):30-41.

28.

Preethi

Mangalassery

Shradha

, et al. Cashew apple pomace powder enriched the proximate, mineral, functional and structural properties of cereal based extrudates. Lwt. 2021;139:110539.

29.

Manders

Little

Forbes

Candow

. Insulinotropic and muscle protein synthetic effects of branched-chain amino acids: potential therapy for type 2 diabetes and sarcopenia. Nutrients. 2012;4(11):1664-1678.

30.

Amanoudo

M-J

Kassa

Wedjangnon

Biaou

Ouinsavi

. Yield gap in cashew plantings (Anacardium occidentale L) in West Africa: status, causes and prospects. AFF. 2022;11(4):140-153.

31.

Preethi

Rajkumar

Shamsudheen

Nayak

. Prospects of cashew apple-A compilation report. Tech Bull. 2019;2:1-28.

32.

Raj

Bansal

Kaushik

, et al. Immunity boosters at alimentary and physical levels in relevance to Covid-19. 2019.

33.

Okonkwo

Ozoude

. The impact of processing on the nutritional, mineral and vitamin composition of palm kernel nut (Elaeis guineensis). Afr J Food Sci. 2015;9(10):504-507.

34.

Babu

. A Study on Marketing Mix of Delicious Cashew Company. 2022.

35.

Jiang

Charoensiddhi

Xue

, et al. A review on the gastrointestinal protective effects of tropical fruit polyphenols. Crit Rev Food Sci Nutr. 2023;63(24):7197-7223.

36.

Sruthi

Naidu

. Cashew nut (Anacardium occidentale L.) testa as a potential source of bioactive compounds: a review on its functional properties and valorization. Food Chem Adv. 2023;3:100390.

37.

Aslam

Hassan

Mehak

, et al. Exploring the potential of cashew waste for food and health applications-a review. Future Foods. 2024;9:100319.

38.

Cordaro

Siracusa

Fusco

, et al. Cashew (Anacardium occidentale L.) nuts counteract oxidative stress and inflammation in an acute experimental model of Carrageenan-induced Paw edema. Antioxidants. 2020;9(8):660.

39.

Potočnik

Gorgieva

Trček

. From nature to lab: sustainable bacterial cellulose production and modification with synthetic biology. Polymers (Basel). 2023;15(16):3466.

40.

Naka

Koua

Mohamed

Soumaila

. Antioxidant and antibacterial activities of cashew (Anacardium occidentale L.) apple juice concentrated from western three regions of Côte D’ivoire. J Appl Biosci. 2019;141:14343-14352.

41.

Onuh

Idoko

Yusufu

Onuh

. Comparative studies of the phytochemical, antioxidant and antimicrobial properties of cashew leaf, bark and fruits extracts. Am J Food Nutr. 2017;5(4):115-120.

42.

da Silva

de Oliveira Braga

de Oliveira

ECS

, et al. Cashew apple byproduct: gastroprotective effects of standardized extract. J Ethnopharmacol. 2021;269:113744.

43.

Runjala

Kella

. Cashew apple (Anacardium occidentale L.) therap eutic benefits, processing and product development: an over view. Pharma Innovation. 2017;6(7, Part D):260.

44.

Ojediran

Olorunlowu

Oyekola

Olagoke

Emiola

. Cashew apple: nutritional composition, nutritive value and potentials as commercial feedstuff for livestock. Aceh J Anim Sci. 2024;9(3):128-137.

45.

Sharma

Kumar

Thakur

. Comprehensive review on nutraceutical significance of phytochemicals as functional food ingredients for human health management. J Pharmacogn Phytochem. 2019;8(5):385-395.

46.

Pham

Tran

TYN

Nguyen

TXT

Dao

Ngo

. Evaluating polyphenol and ascorbic acid contents, tannin removal ability, and physical properties during hydrolysis and convective hot-air drying of cashew apple powder. Open Chem. 2024;22(1):20240067.

47.

Aluko

Kassim

Makule

. Underutilized cashew apple fruit: its utility and development as a source of nutrients and value added products in Tanzania. Environ Res. 2023.

48.

Niveditha

Veena

Shweatha

. Formulation of cashew apple-based products for nutrition-centric sustainability. 2024.

49.

Atta

Ekissi

GSE

Fagbohoun

Kouamé

. Physicochemical and sensory parameters of cashew apple jam (Anarcadium occidental L.) harvested in Bondoukou area (North East, Côte d’Ivoire). OARJBP. 2021;2(2):031-040.

50.

Chen

Guo

, et al. The nutritional and bio-active constituents, functional activities, and industrial applications of cashew (Anacardium occidentale): a review. Food Front. 2023;4(4):1606-1621.

51.

Esakkimuthu

Anitha

. Assessing key constraints in cashew production: insights from Kerala and Tamil Nadu, India. Adv Res Teach. 2024;25(5):362-372.

52.

Mendes

Costa

Vicente

Oliveira

MBP

Mafra

. Cashew nut allergy: clinical relevance and allergen characterisation. Clin Rev Allergy Immunol. 2019;57:1-22.

53.

Mgeni

Mtashobya

Emmanuel

. Bioethanol production from pineapple fruit waste juice using bakery yeast. Heliyon. 2024;10(19):e38172 . doi:https://doi.org/10.1016/j.heliyon.2024.e38172

54.

Hegde

. Nutritional composition and antioxidant potential of karonda (Carissa spp.) fruit and its processed products. Punjab Agricultural University; 2020.

55.

Rathour

Behl

Dhashmana

, et al. Non-food crops derived lignocellulose biorefinery for sustainable production of biomaterials, biochemicals and bioenergy: a review on trends and techniques. Ind Crop Prod. 2023;204:117220.

56.

Zafeer

Bhat

. Valorisation of agro-waste cashew nut husk (Testa) for different value-added products. Sustain Chem Clim Action. 2023;2:100014.

57.

Kannan

Rangarajan

Manjare

Pathak

. Microbial production of value-added products from cashew apples-an economical boost to cashew farmers. JPAM. 2021;15(4):1816-1832.

58.

dos Santos Lima

da Silva

FLH

Gomes

da Silva Neto

. Chemical composition of the cashew apple bagasse and potential use for ethanol production. Adv Chem Eng Sci. 2012;2(4):519-523.

59.

Sahie

LBC

Soro

Kone

Assidjo

Yao

. Some processing steps and uses of cashew apples: a review. FNS. 2023;14(1):38-57.

60.

Nnamani

Anozie

. Biofuel production potential of Anacardium occidentale (cashew). IJRIAS. 2024;9(10):415-421.

61.

Sharma

Gaur

Sirohi

Larroche

Kim

Pandey

. Valorization of cashew nut processing residues for industrial applications. Ind Crops Prod. 2020;152:112550.

62.

Awogbemi

Von Kallon

. Application of biochar derived from crops residues for biofuel production. JFUECO. 2023;15:100088.

63.

Barasa

. The potential for bioethanol fuels to reduce greenhouse gas emissions from household cooking in urban informal settlements: A case study of Kibera, Kenya. University of Nairobi; 2018.

64.

Tran

Paramasivam

Nguyen

. Biomass: A Versatile Resource for Biofuel, Industrial, and Environmental Solution. IJASEIT. 2024;14(1).

65.

Emmanuel

Mgeni

Gervas

Mtashobya

. Bioethanol production from concentrated fruit wastes’ juice enhanced with fermentable sugar from millet (Panicum miliaceum). Biofuels. 2024;16(5):1-7.

66.

Sierra-Baquero

Catarino

Costa

, et al. Insights into the cashew production system in Guinea-Bissau: implications for agroecosystem sustainability. Front Sustain Food Syst. 2024;8:1439820.

67.

Makule

Dimoso

Tassou

. Precooling and cold storage methods for fruits and vegetables in Sub-Saharan Africa-a review. Horticulturae. 2022;8(9):776. Publisher Full Text. 2022.

68.

Stéphane

Halbin

Charlemagne

. Comparative study of physical properties of cashew nuts from three main production areas in Côte d’Ivoire. Agric Sci. 2020;11(12):1232.

69.

Bruce

Vinuales

. SDG 7: Access to affordable, reliable, sustainable, and modern energy for all. Cambridge Handbook on International Law and the SDGs (2021). 2021.

Potential Contributions of Cashew Apple Juice to Nutrition,Medicine and Bioethanol Generation: An Outlook

Abstract

Keywords

Introduction

Phytonutrients and Phytochemicals from Cashew Apple Juice: Benefits and Challenges

Bioethanol Production from Cashew Apple Juice: Benefits and Challenges

Conclusion

Materials and Methods

Footnotes

Acknowledgements

ORCID iDs

Funding

Declaration of Conflicting Interests

Data Availability Statement

References