Microbiological, antioxidant and physicochemical stability of a fruit and vegetable smoothie treated by high pressure processing and stored at room temperature

FERNANDEZ, M.V.; DENOYA, G.I.; JAGUS, R.J.; VAUDAGNA, S.R.; AGÜERO, M.V.

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2019 vol. 105 p. 206 - 210

0023-6438

This study aims to evaluate the physicochemical, antioxidantand microbiological stability of a fruit and vegetable smoothie treated with apreviously optimized high pressure processing treatment (HPP: 630MPa, 6min,20ºC), stored at 25ºC. The control samples presented a significant increase inmicrobiological counts during the first days, while treated samples showedcounts below the detection limit (<1.0logCFU/g) throughout the 26 days ofstorage. Total soluble solids and pH did not change with treatment or alongstorage. Initially, HPP-treatment reduced pectinmethylestearase, peroxidase andpolyphenoloxidase activities (PME, POD, PPO) by 83.9%, 31.4%,and 9.7%,respectively. During storage, PPO was maintained whereas POD decreasedsignificantly on treated and control samples, while PME decreased on control,the slow value of treated ones was maintained. All the antioxidant indicatorspresented an initial increase in their values (5-75%) with treatment,presenting similar or better performance than control during storage. Allsamples presented initially a reddish color (a*: 12.4±0.8) tending towards anorange-brownish color with storage time, probably due to the significant lossof betacyanin, smoothie´s main red pigment. In conclusion, although adjustmentsare necessary to achieve pigments´s stability, HPP-treatment is adequate toensure the microbiological and antioxidant stability of the product at 25ºC.