Application of thermosonication for Aloe vera (Aloe barbadensis Miller) juice processing: Impact on the functional properties and the main bioactive polysaccharides

Abstract

The impact of thermosonication on the functional properties and the main polysaccharides from Aloe vera was investigated. Thermal processing was used for comparison purposes. Acemannan was the predominant polysaccharide in Aloe vera juice followed by pectins. Interestingly, thermosonication promoted a minor degradation of the acetylated mannose from acemannan than thermal processing. On the other hand, the degree of methylesterification of pectins was slightly reduced as a consequence of thermosonication. Further, swelling and fat adsorption capacities were improved by thermosonication. Thus, the highest values for swelling (>150 mL/g AIR) and for fat adsorption capacity (∼120 g oil/g AIR) were observed when thermosonication was performed at 50 °C for 6 min. Moreover, high inactivation of L. plantarum (∼75%) was observed when thermosonication was carried out at 50 °C for 9 min. Interestingly, thermosonication promoted a similar color change (ΔE = 7.7) to the modification observed during pasteurization carried out at 75 °C for 15 min (ΔE = 8.2 ± 0.9). Overall, these results suggested that thermosonication could be a good alternative to thermal procedures of Aloe vera juice, since not only caused minor degradation of bioactive polysaccharides but was also able to improve functional properties.