Exploring optimal high-pressure processing conditions on a (poly)phenol-rich smoothie through response surface methodology
Cristina Matías, Iziar A. Ludwig, Concepción Cid, María-José Sáiz-Abajo, María-Paz De Peña
Abstract
Fruit and vegetable-based smoothies offer an excellent way to increase the consumption of (poly)phenols. Among preservation technologies, required to extend their shelf-life, high-pressure processing (HPP) coped with the main drawback of traditional treatments. In this study, response surface methodology (RSM) was used to predict the optimal combination of pressure and holding time to obtain a microbiologically safe beverage without compromising sensory properties and (poly)phenols. Thus, different pressure levels (300–600 MPa) and holding times (2–10 min) were applied to a (poly)phenol-rich green smoothie. All HPP-treated smoothies showed reductions in microbial counts compared to untreated smoothie, and no changes in pH, total soluble solids, total phenolic content, antioxidant capacity and colour parameters, except a decrease of red/green coordinate (a*), and then maintaining the original green colour. The several (poly)phenol subclasses determined by LC-MS/MS were differently influenced by HPP conditions, even total (poly)phenolic compounds were similarly affected among HPP treatments. The overall desirability function revealed 600 MPa and 6 min as the optimal combination of pressure and holding time on the smoothie. Our research highlights the effectiveness of pressure-based technologies as preservation tool in fruit and vegetable-based beverages, along with the maintenance of their appreciated characteristics, such as colour or (poly)phenolic compounds.