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Microbiological efficacy of Pressure Assistated Thermal Processing in combination with natural extracts against Bacillus amyloliquefaciens spores

Research Scholar

Suresh Devatkal, Food Science and Technology (India)
Jeremy Somerville, Co-Researcher
Rarinthorn Thammakulkrajang, Co-Researcher
Ahmed Yousef, Co-Researcher
V.M. (Bala) Balasubramaniam, Faculty Mentor


Suresh Devatkal is a visiting scholar from the Indian Council of Agricultural Research, India. His research interests include meat science, functional meat products, natural preservatives and novel food processing technologies. He has been awarded the Indian Government's CREST fellowship for his research training on emerging food processing technologies in the Department of Food Science and Technology at The Ohio State University. He is currently conducting research on pressure assisted thermal sterilization and use of natural fruit peel extracts in enhancing the inactivation of bacterial spores during pressure-thermal processing of low acid foods.

What is the issue or problem addressed in your research?

Pressure assisted thermal processing (PATP) is an emerging technology that could be used to produce shelf stable low-acid foods. The use of natural antimicrobial compounds during high pressure processing is of interest due to the potential of reducing process severity and amount of artificial food additives. Pomegranate peel and tamarind pulp are natural sources of phenolic compounds having antimicrobial and antioxidant activities. The objective of this study was to evaluate the use of pomegranate peel and tamarind pulp extracts in enhancing lethal effect of PATP.

What methodology did you use in your research?

Spores of Bacillus amyloliquefaciens TMW 2.479 Fad 82 (approximately log 8 CFU/ml) were used to study the PATP process efficiency. Aqueous extracts of pomegranate peel (PPE) and tamarind pulp extract (TPE) were prepared in boiled deionizer water (1:5) and sterilized using autoclave/ 0.45 micron syringe filters. Spores samples (aliquots of B. amyloliquefaciens (0.2 ml) 1.8 ml of 50Mm HEPES buffer, PPE and TPE) were treated in a high pressure unit at 600 MPa and 105 ⁰C for 0, 1, 2, 3 and 5 min and spore survivors were analyzed by spread plate technique. Results were compared with samples treated by thermal processing (105 ⁰C, 0.1 MPa). B. amyloliquefaciens spores were inactivated to undetectable levels after PATP holding time in natural extracts.

What are the purpose/rationale and implications of your research?

Natural fruit peel extracts meet the consumer demand for use of natural preservatives in processed foods. Thus the PATP and natural extracts could be combined to produce shelf-stable food products with superior quality attributes and added health benefits. This technology has the potential applications in processing of shelf-stable value added heat sensitive foods such as meat and egg products.