HEAT INDUCED AND SALT MEDIATED INTERACTION BETWEEN MILK AND SORGHUM PROTEINS
| dc.contributor.advisor | Yogesh Khetra | |
| dc.contributor.author | SOLANKI ASHISH ARJANBHAI | |
| dc.date.accessioned | 2023-12-06T12:12:01Z | |
| dc.date.available | 2023-12-06T12:12:01Z | |
| dc.date.issued | 2022 | |
| dc.description.abstract | The global protein market is witnessing a significant increase owing to the growing consumer demands for healthy and nutritious foods. Present protein demand has been largely met by animal proteins particularly milk proteins. Good quality cost-effective composite foods have been developed in the past by combining milk and cereals together. In the present study, the interaction between sorghum (Sorghum bicolor) and milk proteins was explored. Despite being fifth most important cereal crop, sorghum is underutilized. In this context, manufacturing of sorghum and milk proteins composites can be of a great significance to address the increasing protein demands of consumers in a cost-effective manner. Sorghum and milk proteins were interacted together through application of heat and salt. A method for preparation of sorghum protein isolate (SPI) yielded 81.11% protein (w/w) from sorghum flour. Proximate composition, physico-chemical properties and techno-functional attributes of sorghum flour and SPI were determined. To determine the interaction between SPI and milk proteins, a SPI-skim milk composite protein matrix was prepared in such a way that each of the components i.e. SPI and skim milk supplied half of the total protein content. Skim milk alone was used as control. All samples were then heated at four different temperatures viz. 30⁰C (control), 70⁰C, 80⁰C and 90⁰C for thirty minutes each to induce protein-protein interactions. While for salt induced interaction, sodium bisulphite salt was added in samples at four different concentrations i.e. 1%, 2%, 3% and 4%. These salt added samples were kept at 30⁰C for 30 minutes, which allowed time to salt for its action. The pH of skim milk-SPI composite was lower than skim milk. Particle size showed that at each treatment, size of composite protein matrix was higher than skim milk protein. Zeta potential also indicated some signs of interaction. While flow curve displayed lower viscosity values for composite protein compared to milk protein at each level of treatment. Whereas, FTIR spectroscopy didn’t indicate any sign of interaction. Instrumental colour values also showed that L*, a* & b* values were lower in composite protein matrix compared to milk protein in case of heat and opposite trend was observed in salt induced interaction. SDS-PAGE analysis also revealed that interaction between proteins was increased as intensity of heat increased. Aggregation of protein molecules was higher in case of salt induced interaction compared to heat. The Heat treatment causes unfolding of proteins, thereby exposing the hydrophobic core, disulphide bonds and free sulfhydryl groups, which becomes accessible for bond formation via oxidation of free sulfhydryl groups or by rearrangement of existing disulphide bonds. While in case of salt, either electrostatic interactions or a balance between electrostatic force and hydrostatic interaction was responsible for association of proteins. More studies are required to investigate milk and sorghum protein interactions and the functionality of composite protein. | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810202260 | |
| dc.language.iso | English | |
| dc.pages | 64 p. | |
| dc.publisher | ICAR-NDRI, KARNAL | |
| dc.sub | Dairy Technology | |
| dc.theme | DAIRY TECHNOLOGY | |
| dc.these.type | M.Tech. | |
| dc.title | HEAT INDUCED AND SALT MEDIATED INTERACTION BETWEEN MILK AND SORGHUM PROTEINS | |
| dc.type | Thesis |