Physiological, biochemical and microbiological responses of minimally processed and whole beet roots submitted to postharvest treatments

Author(s)

Andressa Araujo Picoli

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2008-10-10

Examining board members

Ricardo Alfredo Kluge; Giuseppina Pace Pereira Lima; Marta Helena Fillet Spoto

• Advisor: Ricardo Alfredo Kluge

Abstract

The purpose of the present work was to evaluate physiological, biochemical and, microbiological aspects of Early Wonder whole and minimally processed beet roots submitted to different treatments. The following treatments were applied: ethylene (1000µL L-1), 1-MCP (300nL L-1) and, salicylic acid (500mg L-1). After treatments, beet roots were stored at 5oC during 10 days. It was observed that salicylic acid promoted decrease of soluble solids, pH and, respiratory rates of minimally processed beet roots. It was also noted differences between whole and minimally processed beet roots physiology. This difference was observed by the high values of respiratory and ethylene production rates in the minimally processed beet roots. Psychrotrophic bacteria and total coliforms count for minimally processed beet roots were within acceptable limits for 10 days of storage. The presence of coliforms at 45ºC and Salmonella was not detected. Storage at 5ºC was effective to control the metabolic activity and to keep food safety of minimally processed beet roots. The injuries occurred during the minimal processing induced the increase of phenylalanine ammonia-lyase activity. However, the use of salicylic acid decreased the activity of this enzyme. The treatments applied on whole and minimally processed beet roots have little influence on betalains and total phenol concentration. It was not detected astringency on beet roots Early wonder tissues. (AU)