Agricultural waste is prevalent in Singapore, with food waste alone making up 11% of the total waste generated in 2023. However, there have been ongoing efforts to tackle this challenge and these movements are gaining momentum. Driven also by a commitment to transform Singapore’s upcycling culture, our team embarked on an innovative project to repurpose agricultural by-products, with a particular emphasis on soursop fruit for skincare use.

Guided by the United Nations Sustainable Development Goals (UN SDGs), specifically Goal 11, on sustainable cities and communities, we explored ways to upcycle fruit seeds into a widely consumable product.

Why soursop?

As self-love becomes increasingly embraced in today’s world, we see the emergence of rituals such as self-care as a popular expression. Recognising this trend, our team conducted in-depth research and discovered that oil extracted from soursop seeds possesses antioxidant properties that benefit the skin.

This insight led to the realisation that these seeds, currently an underutilised waste product, could be upcycled into a valuable ingredient for the cosmetic and skincare market. Our primary audience includes industry experts and businesses in the skincare, sustainable and upcycling industry who might be intrigued by this.

What goes on behind the scenes?

The cold press method is used to extract high-quality oil from soursop seeds, a typically discarded agricultural byproduct. This technique preserves the oil’s antioxidant properties, making it suitable for potential skincare applications. The process integrates scientific methods such as toxicity testing on mammalian cells, acidity and antioxidant assessments, ensuring maximum yield while maintaining the oil’s quality and minimising environmental impact.

Beyond the scientific portion of this, we are keen to exemplify sustainable innovation by transforming waste into valuable resources. This reduces environmental harm, promotes sustainable practices, and helps create economic opportunities. The extracted oil’s antioxidant and moisturising properties highlight its potential in skincare, showcasing how science can drive meaningful and sustainable solutions.

Support from Singapore Polytechnic and Collaboration with TK Biofarm

Throughout the journey, we are thankful to our lecturers at Singapore Polytechnic (SP) who have provided essential support through funding, mentorship, and resources. Their guidance has helped the team improve the extraction process, ensuring that the extracted oil is of the highest quality. SP’s network of industry experts has also connected us with key players in the skincare and biotechnology industries, allowing us to enhance our product.

For example, we collaborated with TK Biofarm, a start-up company in Malaysia, that specialises in developing new products from agricultural waste. We worked with them on conducting research around soursop seed oil with the end goal of commercialising it. With TK Biofarm’s sponsorship, resources and expertise, we continue to refine our extraction process and we hope to bring to market a product that is both effective and environmentally responsible.

Successes

Our tests, including sensory analysis, toxicity, and antioxidant testing, have yielded promising results. It shows the potential of soursop seed oil as a sustainable, natural ingredient for the cosmetic industry.

In addition, the oil boasts a pleasant aroma, low levels of free fatty acids, and natural antibacterial properties, making it highly suitable for diverse skincare formulations. Its benefits include hydration, brightening and anti-ageing effects, underscoring its value as an ingredient that combines functionality with sustainability.

What we wish to achieve

Through this, we wish to determine the most suitable oil extraction method which allows for maximum yield while preserving the oil’s antioxidant properties for potential use in skincare. By conducting the toxicity, acidity and antioxidant tests, we hope to discover that the oil does not pose any negative side effects and improves skin health through its antioxidant properties. Finally, our end goal culminates in bringing to market our product to increase awareness of the upcycling culture of agricultural waste, and introduce a new and sustainable product into the skincare market.

Contributed by: S Dhasna Presyl, Chee Kai Xuan, Ramamoorthy Muthuponnarasi and Lee Zheng Teng from Singapore Polytechnic.

Images: Singapore Polytechnic and Envato