Åse R. Grendstad’s doctoral research shows how better raw materials, smart processing, and deeper consumer insight can extend the shelf life of fermented dairy products. This can help reduce food waste in both households and the food industry.
Below, she answers four questions about her research:
Why is this research important?
It is important to study this field because a large share of the world’s population is still undernourished or lacks stable access to sufficient food, while enormous amounts of food are wasted every year.
In Norway, both households and the food industry contribute significantly to food waste. Research is therefore essential to develop measures that can reduce waste through better use of raw materials, more efficient production, and products with longer shelf life. This is crucial for achieving the UN Sustainable Development Goals and ensuring sustainable food systems in the future.
What was the aim of your doctoral work?
MThe aim of the thesis was to gain a deeper understanding of how raw materials, processing parameters, and consumer insight can be used to extend the shelf life of fermented dairy products and reduce food waste. The overarching goal was to identify strategies that can reduce waste among both consumers and industry, through optimized product quality and extended shelf life.
What are your most important findings?
The findings show that a two-pronged approach—combining consumer insight with product optimization—is necessary to reduce food waste. The results point to several recommended measures:
- Provide consumers with knowledge beyond date labeling, including clear, product-specific advice on sensory assessment and food safety, so they can make informed decisions even after the expiration date.
- Optimize processing parameters: Mechanical post‑treatment after fermentation and adjustments to fermentation temperature can help extend the shelf life of fermented dairy products.
- Improve raw material quality, particularly through better milk logistics and hygiene practices, to ensure consistent product quality.
- Reassess date labeling based on precise, knowledge-based evaluations that avoid unnecessarily short shelf-life dates.
What is the potential impact of your research:
The research shows that food waste can be reduced by extending the shelf life of fermented dairy products through improved raw material quality, optimized processing, and more accurate methods for determining shelf life. This work provides new knowledge that can strengthen product quality in the dairy industry and lead to less waste.
It also shows that consumers’ attitudes influence how much food is discarded, highlighting the need for clear, product-specific guidance to support their decision-making. Sensory quality assessment and microstructural analysis are emphasized as valuable tools for quality control and shelf-life testing. In a broader perspective, this research can contribute to national and international efforts to reduce food waste and improve resource efficiency.
FAct box:
Åse Riseng Grendstad
- Previous education: Master’s in Food Science, NMBU
- From: Oslo, Norway
- Has now completed her PhD at NMBU’s Faculty of Chemistry, Biotechnology and Food Science
- Main supervisor: Paula Varela- Tomasco
- Co-supervisors: Davide Porcellato, Ingunn Berget og Hilde Kraggerud
- Title of the thesis:
- English: Reducing food waste: Improving shelf life and sensory quality of fermented dairy products by product optimization and consumer insights
- Norwegian: Reduksjon av matsvinn: Forbedring av holdbarhet og sensorisk kvalitet på fermenterte meieriprodukter gjennom produktoptimalisering og forbrukerinnsikt