Oil Structuring Using Stearin Fractions Derived From Slaughterhouse By-Products: Effect of Gelator and Oil Type on Physicochemical Characteristics of Structured Oil

This study evaluated the potential of utilizing the stearin fraction of sheep tail and ostrich fats, as by-products of slaughterhouses, to structure various oils (canola, sesame, sunflower, and flaxseed oils). A stable gel was formed at 25% sheep tail stearins (STS) and 30% ostrich stearins (OSS). STS-based structured oils showed needle-like crystals, longer gelling time (19.14–24.75 min), and firmer structure (1.65–2.09 N) alongside higher elastic modulus (G′) and lower oil loss (< 11%) compared to OSS-based, which contained bigger rosette-like crystals. Moreover, oils with higher unsaturation levels and iodine values resulted in lower viscosity, accelerated crystallization rate, improved firmness, and enhanced oil retention. STS-based structured oil showed β'-polymorph, leading to a stronger network and higher melting enthalpy, which completely melted near body temperature, in contrast to the β-polymorph structure of the OSS-based counterpart. Hence, the type of structurant and oil significantly affected the oil structuring process. The oleogel containing flaxseed oil and STS can replace hydrogenated fats (such as shortenings) in food formulations, offering similar textural and melting properties while improving their nutritional profile.