Potential of different mechanical and thermal treatments to control off-flavour generation in broccoli puree

Abstract

The aim of this study was scientifically investigate the impact of the sequence of different thermo-mechanical treatments on the volatile profile of differently processed broccoli puree, and to investigate if any relationship persists between detected off-flavour changes and microstructural changes as a function of selected process conditions. Comparison of the headspace GC-MS fingerprinting of the differently processed broccoli purees revealed that an adequate combination of processing steps allows to reduce the level of off-flavour volatiles. Moreover, applying mechanical processing before or after the thermal processing at 90°C determines the pattern of broccoli tissue disruption, resulting into different microstructures and various enzymatic reactions inducing volatile generation. These results may aid the identification of optimal process conditions generating a reduced level of off-flavour in processed broccoli. In this way, broccoli can be incorporated as a food ingredient into mixed food products with limited implications on sensorial consumer acceptance.

Keywords: (E)-2-Heptenal (PubChem CID: 5283316); (E)-2-Hexenal (PubChem CID: 5281168); (Z)-3-Hexen-1-ol (PubChem CID: 5281167); 1-Pentanol (PubChem CID: 6276); 6-Methylhept-5-en-2-one (PubChem CID: 9862); Broccoli; Dimethyl disulfide (PubChem CID: 12232); Dimethyl trisulfide (PubChem CID: 19310); GC–MS fingerprinting; Hexanal (PubChem CID: 6184); Microstructure; Nonanal (PubChem CID: 31289); Octanal (PubChem CID: 454); Off-flavour formation; Vegetable processing.