Mr. Subramoni will present his Ph.D. viva voce examination as per the detail:

Date: Monday, 3 October 2022 

Time: 10.00 a.m. IST, 3.30 p.m. AEST

Zoom details:

Please click this URL to start or join. https://monash.zoom.us/j/87660734504?pwd=dmVUT0prWmlJMVdZWnB5MUhUWVhNUT09 

Or, go to https://monash.zoom.us/join and enter meeting ID: 876 6073 4504 and passcode: 570599

Venue in the Academy: Cisco TP Room, Ground Floor, IITB-Monash Research Academy

External Examiner: Dr. S.K. Giri, ICAR

Chairperson: Prof. Yogendra Shastri

Internal Examiner: Prof. K.V. Venkatesh

Supervisors: Prof. Amit Arora, Prof. Antonio Patti

Title: High-quality protein extraction from plant-based sources

Abstract: 

High-quality protein extraction from plant-based sources

The environmental impacts of animal-protein production, combined with the increased protein demand, necessitate the development of new dietary strategies to produce proteins. Simultaneously, the neo-protein sources need to be nutritionally equivalent to animal-protein while maintaining the quality of the protein. An initial approach for the green and sustainable extraction of plant-proteins has been explored in the current work. Peanut oilcake (by-product of oil industry) was chosen as the feedstock for protein extraction. The proximate composition of the feedstock revealed that the major component in oilcake was protein (51.8%), followed by carbohydrates (31.1%), lipids (12.9%) and ash (4.2%). Enzymes Alcalase, Neutrase, and Flavorzyme were chosen to extract proteins in the form of soluble hydrolysates. Nearly 88.5% of the total protein was extracted by developing a two-tiered extraction process. The optimised processing conditions for the primary extraction were as follows: hydrolysis temperature 550C, pH 8.0 (for Alcalase) / 500C pH 7.0 (for Neutrase and Flavorzyme), the ratio of raw material: buffer 1:20 (W/V), extraction time 16 h, enzyme concentration 2% (v/v).  At these conditions, protein extraction for alcalase was 38.5% ± 3.4, neutrase was 39.2% ± 3.2, and flavorzyme was 37.4% ± 2.7. Formation of low molecular weight hydrolysates (0.5 kDa – 5 kDa) were confirmed by SDS-PAGE, size exclusion chromatography, and MALDI-TOF. The residual protein (~50%) in the oilcake was extracted in a secondary extraction by employing a mild alkaline enzyme ‘hybrid’ approach at pH 8 and 0.5% enzyme concentration (v/v) and concentrated to 94.3% by ultrafiltration. Moreover, the enzymes used for the second hydrolytic process was recovered and recycled 5 times, with a ~10% loss in activity observed post each cycle. In vitro digestibility for the hydrolysates were between 94 – 96%.  Excessive hydrolysis however decreased the emulsifying potential, owing to the production of smaller peptides. Foaming potential and foam stabilities of hydrolysates were found to be higher than unhydrolysed protein. Apart from protease, peanut protein concentrates were produced by employing α-amylases and plant-based proteases. The influence of ultrasound pretreatment on peanut oilcake was evaluated in terms of protein extraction efficiency. The maximum extraction (61.5% ± 1.5) was observed when the ultrasound frequency was 20 kHz (60% power), with a treatment time of 45 mins. Finally, the techno-economic feasibility of protein extraction and production from peanut oilcakes was analysed. It was observed that the venture would be successful at the base-case scenarios with a net profit of US$ 47 million, when the procurement cost of oilcake is US$ 0.6 /kg, and the selling price of protein hydrolysates is set at US$ 3/kg. Likewise, it was understood that the plant must consider a minimum plant operation of 330 days, when the cost-price of oilcake is greater than US$ 0.6/kg, and the cost-price of enzyme is greater than US$ 20/kg. The process exhibited an NPV of US$ 350 million per year under best-case conditions. The overall analysis revealed that peanut oilcake, which is currently being sold as animal-feed or converted to biogas, could be utilised as an excellent source of high-quality proteins. The experimental analyses and techno-economic simulation validated the scale-up feasibility of a green and sustainable protein extraction process from peanut oilcakes. In summary, this research affirmed the hypothesis that peanut oilcake can be a potential source of protein isolates and protein hydrolysates that can be employed in the food and nutrition sector. 

 
Event Date: 
Monday, October 3, 2022 - 10:00 to 11:30