Aplicação de ultrassom em mangas ‘Tommy Atkins’ minimamente processadas: aspectos fisiológicos e de qualidade

Abstract

Currently is growing to search for healthier eating with that comes the possibility for inclusion of fruits and vegetables in the diet. Mango fruit is widely consumed and produced in Brazil and fresh – cut (FC) represents convenience because them are products that comes ready for consumption without loss of time with operations peeling, cutting, etc., and these steps there is a stress tissue leading to generation of free radicals that can lead to a degradation fruit, so it is necessary a type of processing that minimize the loss of quality and yet ensures the safety of the final product. In this context arises the ultrasound (US) that is an emerging technology that has potential for exploitation and utilization. The ultrasonic waves cause primarily tissue compression and expansion, whose the results will depend on the food matrix. This study aimed to evaluate the effect of US in quality of FC 'Tommy Atkins' mangoes, analyzing the antioxidant defense system, metabolism oxidative compounds and the activity of cell wall hydrolytic enzymes. The samples were exposed to 25 kHz frequency sonication for 30 minutes in US bath. It was observed tha t the treatment caused a reduction in titratable acidity (TA) and soluble solids (SS), but after seven days of storage at 4 o C, maintaining the high SS/TA ratio (46.54). The sugars was also reduced (15%) and water incorporated (4.6%), which indicates a change in cell structure, that can be evidenced by decreased in firmness after seven days (from 241.73 to 139.38 N) and increased activity of pectinmethylesterase. The color wa s degraded after seven days (ΔL = 3.24 and ΔC = 4.42), resulting in darkening, but the control samples also darkened. In relation to the antioxidant system, there were no significant changes in order to be a beneficial factor compared to other preservation methods, particularly only to the loss of vitamin C (328.10 to 190.18 mg ascorbic acid/kg weight fresh (WF), still there was a reduction in lipid peroxidation of membrane (from 23.58 to 18 η mol MDA/g WF). It concluded to base on this study, FC 'Tommy Atkins' mango has its drawbacks on firmness and color, however, did not affect severely the enzymatic and non – enzymatic antioxidant x systems, and lead to a reduction in sugar content. However, it is clear the necessitate to explore the application of this technology in post harvest fruits physiology as well as to optimize and to combine the technique with other processes that reduce their negative effects and promote the positives.