Rheological behaviour of sesame (Sesamum indicum L.) protein dispersions

Techno-functional attributes of oilseed proteins: influence of extraction and modification techniques

Plant-based protein isolates and concentrates are nowadays becoming popular due to their nutritional, functional as well as religious concerns. Among plant proteins, oilseeds, a vital source of valuable proteins, are continuously being explored for producing protein isolates/concentrates. This article delineates the overview of conventional as well as novel methods for the extraction of protein and their potential impact on its hydration, surface properties, and rheological characteristics. Moreover, proteins undergo several modifications using physical, chemical, and biological techniques to enhance their functionality by altering their microstructure and physical performance. The modified proteins hold a pronounced scope in novel food formulations. An overview of these protein modification approaches and their effects on the functional properties of proteins have also been presented in this review.

Enhancing Rheological and Textural Properties of Gelatin-Based Composite Gels through Incorporation of Sesame Seed Oleosome-Protein Fillers

In this study, the protein and oleosomes of sesame seeds were extracted individually and used to prepare a gel composed of gelatin, protein, and oleosomes. Mixtures of gelatin and sesame seeds protein were prepared, and oleosomes with different percentages (0, 10, 20 and 30% of their weight) were used. Different amounts of oleosomes in the composite gel samples were examined for their morphological, rheological, and textural properties. The results of the viscoelastic properties of different composite gel samples indicated that a higher percentage of oleosomes would increase the storage modulus (G'), loss modulus (G″), and complex viscosity (η*). The storage modulus of all gel samples was greater than the loss modulus, suggesting a solid behavior. So, in the sample with 30% oleosome, the storage modulus and the loss modulus reached 143,440 Pascals and 44,530 Pascals. The hardness and breaking force in samples containing 30% oleosome reached 1.29 ± 0.02 and 0.17 ± 0.02, respectively. In general, it can be said that composite gels based on gelatin-sesame seed protein modified with oleosome can be used as a part of food components in various dairy products, gelatin desserts, lean meat products and the production of useful products.

Sesame seed protein: Amino acid, functional, and physicochemical profiles

Sesame (Sesamum indicum L.) is an erect herbaceous annual plant with flat seeds. It is one of the oldest cultivated oilseed plants in the world, especially popular in Africa and Asia. The present research objective was to describe a sesame protein isolate, i.e., its amino acid profile, functional and physicochemical properties, zeta potential, and hydrodynamic diameter. The surface charge and hydrodynamic diameter in aqueous solutions were obtained for standard sesame seeds, defatted sesame seeds, and the sesame protein isolate. Defatted sesame seeds yielded the following optimal parameters: salt concentration – 0.6 M, pH – 7, iso-electric point (pI) – 4. The sesame protein isolate was rich in methionine content, which is rare in other plant proteins, but its lysine content was lower than in other isolates. The sesame protein isolate displayed almost identical zeta potential profiles with its pH. The decreasing pH increased the zeta values gradually from the lowest negative value to the highest positive value. The zeta potentials of standard and defatted sesame seeds at pH 7 were –23.53 and –17.30, respectively. The hydrodynamic diameter of the sesame protein isolate (0.33 μm) was smaller than that of sesame seeds (2.64 μm) and defatted sesame seeds (3.02 μm). The sesame protein isolate had a water holding capacity of 1.26 g/g and an oil holding capacity of 3.40 g/g. Its emulsifying properties looked as follows: emulsion capacity – 51.32%, emulsion stability – 49.50%, emulsion activity index – 12.86 m2/g, and emulsion stability index – 44.96 min, respectively. These values are suitable for the sesame protein isolate and are consistent with the literature. The sesame protein isolate was a good source of protein (88.98%). Using sesame proteins as functional components can be an important basis for better knowledge of the relationship between electrical charge interactions in food matrices and the structure, stability, shelf life, texture, structural and functional properties of food. Research prospects include the effects of sesame protein isolates on various food systems.