Cleaning the Rancimat® equipment: long-term effects on results and determination of protocol

• Grant number: 17/03074-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2017
• End date: June 30, 2018
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Marisa Aparecida Bismara Regitano d'Arce
• Grantee: Rafaela Airoldi
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The oxidative stability of oils can be determined by the OSI (Oxidative Stability Index) type apparatus, called Rancimat. Acting through constant air pumping and high temperature, this equipment has the objective of determining the time necessary for the complete oxidation of the lipid sample (period of induction - PI). Due to its ease of use and fast results, Rancimat has been recognized worldwide, including for official analyzes of oils and biodiesel. However, the cleaning of its components is laborious and has been done empirically among users of the equipment. Contamination from oily residues can lead to erroneous results. In the absence of guidelines from the manufacturer, cleaning protocols based on scientific evidence are needed. Thus, the objective of this project will be to evaluate the effect of two cleaning treatments of glassware throughout 40 analyzes, suggesting, at the end of the study, a definitive cleaning protocol. The treatments will be classified as Intensive and Mild, being the first one based on immersion of the pieces in hydroalcoholic solution of 3% KOH. The second will be based essentially on washing with neutral detergent. The PI of the sample will be monitored throughout the project, observing its variations in relation to the control. The presence of oxidation compounds adhered to the glassware will also be evaluated by UV spectrophotometry. We hope to demonstrate the influence of the treatments on the long-term results and, for the first time, to suggest a cleaning protocol that could be used by users from all over the world. (AU)