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VOL. 8, ISSUE 1 (2026)
Investigation of shelf-life and microbial stability in dairy products fortified with pea protein isolate
Authors
Shivraj B Patil, Balasaheb D Landge, Omprakash A Kadam
Abstract
The overall increasing demand for plant
derivedingredients and protein-enriched foods has driven the fortification of
traditional dairy products with plant proteins, such as pea protein isolate
(PPI). However, how PPI will ultimately affect the physicochemical, sensory,
and, most importantly, microbial stability and shelf-life of dairy matrices is
not well elucidated. This work evaluated the shelf-life and microbial stability
of two model dairy systems, namely UHT milk and set-style yogurt, which are
fortified at 2% and 4% w/w with PPI. Control samples (0% PPI) and their
respective fortified versions were tested during a storage period of 35 days at
4°C. In this respect, analyses on microbiological parameters, such as total
aerobic plate count, yeast and mold count, coliforms, and specific spoilage
organisms, were carried out, together with physicochemical parameters, such as
pH, titrable acidity, syneresis, and viscosity, and sensory attributes on a
weekly basis. Indeed, results indicated that fortification with PPI increased
significantly (p < 0.05) the rate of pH decrease and acidity increase in
yogurt, which was paralleled by higher syneresis values. Although PPI addition
did not introduce any microbial contaminant to UHT milk or yogurt, the plant
protein slightly accelerated the growth of microorganisms compared to controls
during storage. These were attributed to improved nutrient levels in milk with
reduced acidity. Sensory panel analyses indicated higher levels of chalkiness
and beany tastes with increased levels of PPI. Conclusion: Fortification of PPI
at 4% extends the shelf life of yogurt by 7 days based on physicochemical
changes. In UHT milk, microbial shelf life will be negatively affected when
fortified with PPI at levels exceeding 4%. The optimized acidification levels,
different compositions of stabilizers, and high standards of cleanliness during
processes of PPI in dairy products are recommended.
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Pages:59-63
How to cite this article:
Shivraj B Patil, Balasaheb D Landge, Omprakash A Kadam "Investigation of shelf-life and microbial stability in dairy products fortified with pea protein isolate". International Journal of Biotechnology and Microbiology, Vol 8, Issue 1, 2026, Pages 59-63
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