Utilization of pumpkin seed protein isolate as a phosphate replacer in model meat emulsions: effects on chemical and techno-functional properties

Özlem Yüncü-Boyacı; Nazlı Aksakal; Ceylin Çam; Ayça Polat; Meltem Serdaroğlu

doi:10.18485/meattech.2025.66.3.45

Özlem Yüncü-Boyacı Ege University, Engineering Faculty, Food Engineering Department, Izmir, Turkey https://orcid.org/0000-0002-9112-1427
Nazlı Aksakal Ege University, Engineering Faculty, Food Engineering Department, Izmir, Turkey https://orcid.org/0009-0001-8878-5900
Ceylin Çam Ege University, Engineering Faculty, Food Engineering Department, Izmir, Turkey https://orcid.org/0009-0006-7499-3713
Ayça Polat Ege University, Engineering Faculty, Food Engineering Department, Izmir, Turkey https://orcid.org/0000-0003-3000-7919
Meltem Serdaroğlu Ege University, Engineering Faculty, Food Engineering Department, Izmir, Turkey https://orcid.org/0000-0003-1589-971X

DOI: https://doi.org/10.18485/meattech.2025.66.3.45

Keywords: pumpkin seed protein isolate, meat emulsion, phosphate replacer, technological properties

Abstract

This study aimed to evaluate the potential of pumpkin seed protein isolate (PSPI) as a natural alternative to phosphates in model meat emulsions. PSPI was extracted from cold-pressed pumpkin seed oilcake using an alkaline solubilization and acid precipitation method. Model meat emulsions were formulated by replacing sodium tripolyphosphate (STPP) with PSPI at three levels (1%, 1.5%, and 2%) and compared with a phosphate-containing control group. Chemical composition (moisture, fat, protein, ash) and techno-functional properties, i.e., pH, water-holding capacity (WHC), total expressible fluid, expressible fat (EFAT), jelly-fat separation, and cooking yield were evaluated. Results showed that the addition of PSPI significantly reduced fat content and increased protein content in comparison to the control. The control sample exhibited the highest WHC and the lowest fat and fluid separation. However, increasing levels of PSPI improved WHC and reduced EFAT values, with the 2% PSPI group exhibiting emulsion stability comparable to that of the control group. In line with the stability analyses, the highest cooking yield was observed in the control group, while the lowest value belonged to the P1 group. Although the functional performance of PSPI was slightly lower than that of STPP in some parameters, PSPI demonstrated notable potential in maintaining key quality attributes, such as moisture retention and emulsion stability. In conclusion, PSPI can serve as a functional and natural alternative to phosphates in meat emulsions, contributing to the development of healthier and clean-label meat products.