Formulation and Processing Optimization of Pea-Based Barista Drink : Effects of Emulsifiers and Calcium Salts

Abstract

As interest in sustainable, plant-based dairy alternatives continues to rise, ensuring stability and functionality is crucial, especially for barista-style applications. This thesis, carried out in collaboration with Sproud, a Swedish company specializing in pea-based milk alternatives. The research focused on two key areas: how different emulsifiers and processing methods affect product formulation, and how calcium salt combinations influence long-term sedimentation stability. In the formulation study, four emulsifiers (Lecithin, Tween 80, saponins, and CITREM) were tested alongside two processing techniques: ultrasonication and microfluidization. These combinations were evaluated for their impact on particle size, foam characteristics, coffee compatibility, and sedimentation. Among the tested options, saponins paired with microfluidization delivered the best results in terms of foam quality and overall emulsion stability. A parallel shelf-life study looked at how different blends of calcium salts affected the physical stability of simplified pea protein suspensions over 42 days. It was found that using lower concentrations of less soluble salts, like tricalcium phosphate, improved particle dispersion and minimized aggregation.
Overall, the findings point to practical strategies for improving both short-term functionality and long-term stability in plant-based barista beverages.

Popular Abstract

As the demand for plant-based milk alternatives continues to rise, driven by health, environmental, and ethical considerations, improving their performance and stability becomes essential. If you’ve ever poured plant-based drink into your coffee, you might have noticed something peculiar: small, beige clumps that form at the bottom of the carton. With their smooth, paste-like texture, these clumps can almost resemble clay. They sometimes stick to the container and resist mixing back in, even after shaking. While the sediment (clumps) itself is harmless and doesn’t indicate spoilage, it can certainly affect the appearance and texture of the drink, creating a less enjoyable experience. This study, conducted in collaboration with Sproud, investigates ways to enhance the performance of their pea-based barista drink, focusing on reducing the formation of clay-like clumps and improving functional properties.

The research focused on two main aspects: improving performance and stability. To assess how performance can be enhanced, Sproud’s Barista drink was recreated using key ingredients, such as pea protein, water, rapeseed oil, sweetener, and minerals, with different emulsifiers, ingredients that help mix oil and water. The study tested four different emulsifiers: lecithin (from rapeseed) Tween 80 (a synthetic variant), saponins (natural compounds from the soapbark tree), and CITREM (a synthetic variant). Each emulsifier was paired with two different processing techniques: ultrasonication, which uses sound waves to break down fat droplets, and microfluidization, a technique that forces liquid through narrow openings at high speeds to create uniform particle sizes. The effectiveness of these methods was compared in terms of their ability to improve stability and foaming properties, with tests to measure particle size, separation over time, foam production, and suitability for coffee applications. In addition to emulsifiers, the study also explored how calcium salts affect long-term stability. Therefore, a simplified version of the drink was made using just pea protein and water, and different combinations of calcium salts were tested. These salts, while providing nutritional benefits, can cause the formation of insoluble crystals that contribute to the sedimentation issue. The samples were monitored for changes in turbidity, texture, and particle stability using laser-based particle size analysis and microscopic imaging.

The results revealed that while Sproud’s current product already performs well, there are several opportunities for improvement. Saponins improved the foaming ability of the product, making it foam more and last longer, regardless of the homogenization technique used. Microfluidization, when paired with saponins, improved both foam and overall product stability. Interestingly, microfluidization also boosted stability when used with lecithin, the emulsifier in Sproud’s current formulation, offering the company a potential pathway to improve product stability while maintaining their existing emulsifier. Additionally, the study examined the impact of different calcium salts on long-term stability. Although the test duration was too short to investigate the formation of the clay-like sediment, samples with lower amounts of tricalcium phosphate, an insoluble calcium salt, demonstrated better stability in particle size over time. This suggests that using more soluble salts could help reduce sedimentation and improve the product's consistency in the long run. These findings suggest that by changing the emulsifier, foaming performance, which is crucial for Barista applications, can be enhanced. Additionally, altering the processing technique improves stability, and optimizing salt combinations could yield even greater benefits.

While the findings of this study are promising, developing a plant-based drink that meets the needs of both consumers and producers requires continuous innovation. As the demand for plant-based alternatives continues to rise, the urgency for products that perform like dairy intensifies. Future research should prioritize long-term stability testing, explore alternative emulsifiers, and optimize calcium salt combinations. Additionally, understanding the effects of lower pH levels on salt solubility and protein stability remains a critical question for the industry. This study demonstrates that with continued research and development, plant-based milk alternatives can evolve to meet dairy performance standards, offering consumers smoother, more stable beverages that excel in application.

• author: Hammelehle, Lucia Theresa and Perbellini, Anna
• supervisor: Anna Fureby
• organization: Food Technology and Nutrition (M.Sc.)
• course: KLTM02 20251
• year: 2025
• type: H2 - Master's Degree (Two Years)
• subject: Agriculture and Food Sciences; Technology and Engineering; Chemistry
• keywords: Pea protein, Plant-based milk, Emulsion stability, Foam capacity, Calcium fortification, Microfluidization, Ultrasonication, Emulsifiers, Particle size, Food engineering nutrition and food chemistry
• language: English
• id: 9189015
• date added to LUP: 2025-05-23 16:16:11
• date last changed: 2025-05-23 16:16:11