Investigation of non-thermal effects of microwave heating in model systems and fruit juices: determination of molecular structure and conformational changes in endogenous enzymes

• Grant number: 17/09730-2
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: September 01, 2017
• End date: August 31, 2018
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Carmen Cecilia Tadini
• Grantee: Rodrigo Nunes Cavalcanti
• Supervisor: Hosahalli Ramaswamy
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: McGill University, MacDonald, Canada
• Associated to the scholarship: 15/25697-0 - Evaluation of the continuous microwave thermal process of liquid foods, BP.PD

Abstract

Fruits are an integral part of a healthy diet. They provide essential micronutrients such as vitamins, minerals, and also antioxidants, phytochemicals, sugars and dietary fiber. Preservation of fruits in the form of purees and juices (FP&J) is very popular as these products are convenient to consume and form an integral part of many formulations. Besides microbial spoilage, quality degradation due to endogenous enzyme activity is also a factor of concern. Nowadays, browning is still a major problem for various fruit products due to lowering of quality, safety, and nutritional value. Microwave heating has been reported to provide superior quality fruit-based products with an extended shelf-life, representing a good alternative to conventional preservation processes. The main purpose of the present research is the investigation of possible thermal and non-thermal effects of microwave heating on the safety and quality aspects of fruit juices. The work is focused on the investigation of the effects of microwave and conventional heating on the molecular structure and conformation of the enzymes polyphenol oxidase (PPO) and peroxidase (POD), which will be measured using Fourier-transform infrared (FTIR), circular dichroism (CD), and intrinsic fluorescence spectroscopy and confocal microscopic techniques. The proposed period at McGill University is important for the acquisition of theoretic and practical knowledge about non-thermal effects of microwave heating, a subject unknown and poorly studied in the literature. The opportunity of Research Internships Abroad (BEPE) at McGill University will contribute to future projects in collaboration with the Department of Chemical Engineering and the Food Research Center (FoRC). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARTINS, CAROLINA P. C.; CAVALCANTI, RODRIGO N.; COUTO, SILVIA M.; MORAES, JEREMIAS; ESMERINO, ERICK A.; SILVA, MARCIA CRISTINA; RAICES, RENATA S. L.; GUT, JORGE A. W.; RAMASWAMY, HOSAHALLI S.; TADINI, CARMEN C.; et al. Microwave Processing: Current Background and Effects on the Physicochemical and Microbiological Aspects of Dairy Products. COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, v. 18, n. 1, p. 67-83, JAN 2019. (12/04073-0, 13/07914-8, 15/25697-0, 17/09730-2)