Thermal stability of phytochemicals, HMF and antioxidant activity in cape gooseberry (Physalis peruviana L.)

Cape gooseberry is a fruit recognised for having relevant contents of health-promoting compounds. Changes in the content of phytochemicals (ascorbic acid, beta-carotene, catechin and epicatechin), hydroxymethylfurfural (HMF) and antioxidant activity of this fruit were studied at various temperatures and times. Ascorbic acid degradation was described by a first order reaction. beta-carotene was not degraded and followed an isomerization reaction from 80 degrees C onwards. Formation of HMF was described with a consecutive zero together with a first order reaction model. The contents of catechin and epicatechin increased at 40 degrees C. More than three competing reactions did not allow to make kinetic modelling. Antioxidant activity followed fractional first order conversion model. Comparison with kinetics found in other fruits showed that health-promoting compounds of cape gooseberry are relatively more stable to heat treatment. This makes cape gooseberry suitable for the preparation of foods (jam, juices and dehydrated fruit) with relevant health-promoting compounds contents. (C) 2017 Elsevier Ltd. All rights reserved.