Waste isn’t the end of the story; it’s the raw material for the next food revolution

Marking a significant step toward healthier and more sustainable food solutions, Dr Srishti Mathur, Assistant Professor, Shoolini University, has developed the first biotechnological method to produce xylitol—a natural, low-calorie sweetener. The diabetic-friendly alternative is created by converting brewer’s spent grain (BSG), the primary by-product of beer production, into a high-value, eco-friendly sugar substitute. Dr Mathur talks more about the research, the challenges involved, and the patents received in interaction with NUFFOODS Spectrum India

What made you come up with the innovation of transforming industrial waste into a valuable resource to help address the growing challenge of diabetes?

The spark came from staring at two massive crises at once: mountains of industrial waste rotting in landfills and millions suffering from diabetes because safe, affordable sugar alternatives are out of reach.

Brewer’s spent grains (BSG), the most overlooked by-product of the brewing industry, caught my eye. Globally, breweries discard over 40 million tonne of BSG every year. It is rich in hemicellulosic sugars, yet 90 per cent ends up as low-value cattle feed or landfill. That’s not just waste; it’s a missed trillion-dollar opportunity hiding in plain sight.

Using Pichia fermentans (procured from Cranfield University, UK), I developed a zero-waste fermentation process that converts BSG into high-purity xylitol at a fraction of the current market price.

My vision is to scale this across India’s more craft breweries first, then take it global, delivering affordable wellness to diabetic patients in emerging markets and proving that sustainability can be profitable. Waste isn’t the end of the story; it’s the raw material for the next food revolution.

Could you tell us more about the biotechnological method to produce xylitol- a natural, low-calorie sweetener?

Turning brewery waste into a powerhouse sweetener is the core of my biotechnological breakthrough. Traditional xylitol comes from chemical hydrogenation of birch wood xylose: costly ($7–10/kg), energy-hungry, and eco-damaging. My enzyme-free process harnesses brewer’s spent grains (BSG), a global 40-million-tonne waste stream, as a zero-cost feedstock, slashing production costs to $2.8–3.2/kg while cutting emissions by 85 per cent.

We’ve piloted this study with Indian breweries, proving scalability. Deploy across multiple Indian craft breweries by 2027, producing approximately 10,000 tonne/year of affordable xylitol for diabetes-prone markets or more applications of xylitol field, turning waste into $100M+ revenue while advancing UN SDGs on zero hunger and climate action. Biotech like this redefines food sustainability, one beer byproduct at a time.

How will this innovation help in circular economy practices?

This innovation is a prime example of circular economy principles in action, transforming brewer’s spent grains (BSG), a vast global waste stream from brewing, into a valuable resource, effectively closing the loop on what was once discarded as low-value material.

My process begins with an enzyme-free pretreatment combining hydrothermal and acid hydrolysis to efficiently unlock fermentable sugars from BSG’s rich hemicellulose content. This feeds into optimised fermentation with Pichia fermentans, scaling from lab to bioreactor levels, followed by straightforward purification steps yielding advanced-purity xylitol crystals.

Environmentally, it reduces waste significantly: Valorizing just one ton of BSG produces substantial xylitol while cutting emissions far below traditional methods. Economically, it converts brewery disposal costs into revenue streams, potentially generating millions in value from India’s brewing sector alone by integrating into existing facilities.

This biorefinery approach fosters industry symbiosis: Brewery waste fuels production for food, pharma, and beyond, aligning with UN SDGs on sustainability and innovation. Scaled up, it’s set to pioneer zero-waste models worldwide, proving that smart biotech can turn liabilities into engines of economic and environmental prosperity. 

How big is the usage of xylitol in the food sector?

Imagine a world where sweetness powers wellness, not worries, xylitol is leading that charge in the food sector. Right now, in 2025, the global xylitol market surges past $1.2 billion, with the food and beverage arena claiming over 50 per cent of the action.

Fuelled by a rocket-like CAGR of 5-6 per cent, it’s blasting toward $2 billion+ by the mid-2030s, supercharged by biotech breakthroughs like mine- turning waste into affordable, sustainable gold. This isn’t just growth; it’s a revolution against diabetes and obesity, where low-glycemic, gut-boosting xylitol redefines “clean label” for billions.

In the future, expect AI-optimised formulations in personalised nutrition, smart gums that adapt to your microbiome, 3D-printed candies for diabetic kids, and zero-waste sweeteners in every pantry. Asia-Pacific leads the hyper-speed expansion, while Europe mandates sugar slashes.

Xylitol isn’t replacing sugar; it’s upgrading humanity’s plate- one bold, brilliant bite at a time.

Did you face any challenges while conducting research?

Brewer’s spent grains are notoriously stubborn: a complex, heterogeneous matrix loaded with lignin and phenolics that fight back at every step. Unlocking fermentable sugars without creating toxic inhibitors (furfural, HMF, acetic acid) felt like cracking a safe blindfolded, countless iterations of pretreatment conditions, endless HPLC runs, and moments when yields refused to budge.

Then came the yeast- Pichia fermentans is powerful, but pushing it to convert real-world hydrolysate at high efficiency demanded relentless optimization of pH, aeration, inoculum timing, and nutrient balance.

My mentors, Dr Dinesh Kumar (Shoolini University) and Dr Vinod Kumar (Cranfield University), were with me in every directionless hour, dissecting data, redesigning runs, and refusing to let setbacks win.

Did you receive any grants from the institute or the government?

No formal grants were awarded for this project, yet we turned that constraint into pure momentum, thanks to the extraordinary network and resourcefulness of my major supervisor, Dr Dinesh Kumar.

With zero dedicated funding, most researchers would have stalled at the lab bench. My supervisors refused to let that happen. Through his decades-long relationships across academia and industry, he opened doors I didn’t even know existed. When we needed pilot-scale bioreactors, he instantly connected us with Himachal Pradesh University (HPU), Shimla and even the basic grounds of collected BSG from the brewery reference. Yeast strain sourced from Cranfield University? Handled by Dr Vinod Kumar, my co-supervisor. Both taught me that real innovation isn’t measured by grant size, but by how cleverly you mobilize people and infrastructure.

You have received four patents. Which are they?

Patents aren’t just paper; they’re the blueprints for a sustainable food revolution, and my work on BSG valorisation has already secured four, with a fifth in the pipeline.

Here are the detailed 4 patents:

                A fermentation method for the production of xylitol from agricultural waste: Patenting the optimized bioconversion of BSG hydrolysate to low-cost, green xylitol at 34+ g/L yields. This scales waste-to-wellness globally. 

                  A method for synthesizing byproducts from brewer’s spent grains: Extending the process to capture co-products like residual proteins and fibers during xylitol extraction, maximising every gram of BSG for circular efficiency. 

              A composition of BSG biscuits and their preparation process: Spotting BSG’s posttreatment edibility, we formulated fiber-rich, low-glycemic biscuits blending BSG flour with whole grains, perfect for diabetic-friendly snacks that turn brewery scraps into shelf-stable superfoods. 

                 A composition of edible BSG bars and their preparation: Similarly, nutrient-packed energy bars with BSG, infused with nuts and dates for antioxidants and sustained energy. These prove BSG isn’t just feedstock; it’s a versatile, human-grade powerhouse for functional foods.

Sanjiv Das
sanjiv.das@mmactiv.com