Application of high hydrostatic pressure to aloe vera (Aloe barbadensis Miller) gel: Microbial inactivation and evaluation of quality parameters

High hydrostatic pressure (HHP) is an innovative technology which minimizes loss of physicochemical and nutritional quality matching consumer demands for fresh-like foods. The aim of this study was to investigate the effect of high hydrostatic pressure (300, 400 and 500 MPa/1, 3 and 5 min) on microbial inactivation and quality parameters of A. vera gel after 60 days of storage. Shelf life was determined successfully by fitting experimental microbial data to the modified Gompertz equation for samples treated at 300 MPa/1 min. The samples treated at 400 and 500 MPa during 1, 3 and 5 min presented undetectable levels of microorganisms' counts. Based on microbiological results, the analysis of quality attributes was focused on the effects of HHP (300, 400 and 500 MPa) during 5 min of processing. Antioxidant activity, which was analyzed by means of total polyphenols content and DPPH-radical scavenging activity, showed a maximum value at 500 MPa. At 400 MPa, vitamin C showed the maximum retention (93%) and vitamin E increased the initial value of the gel. An increase of polysaccharides at 500 MPa also affected the gel firmness. Differences in surface color were also observed. Based on results, application of 500 MPa during 5 min may be successfully used to preserve main quality attributes of A. vera gel.Industrial relevanceThe increasing demand for healthy foods with less physical damage and environmental friendly processing is giving new opportunities for the hurdle-technology concept of foods preservation. In this sense, high hydrostatic pressure presents an innovative technology to improve shelf life of A. vera gel leading to an enhancement of its quality attributes.

► Effect of High Hydrostatic Pressure (300-500MPa/ 1-5 min) on microbial and quality attributes of A. vera gel was analyzed.
► Antioxidant activity, colour, polysaccharides and firmness showed changes among pressurized samples.
► Working at 500 MPa/5 min may successfully used to preserve the quality attributes of the gel.