Aging can be viewed as a quasi-programmed phenomenon driven by the overactivation of the nutrient-sensing mTOR gerogene. mTOR-driven aging can be triggered or accelerated by a decline or loss of re...
1 July 2018 in Journal of Pharmaceutical and Biomedical Analysis
This paper provides an overview of alternatives to conventional thermal treatments and a review of the literature on fruit-juice processing for three key operations in fruit-juice production such as microbial inactivation, enzyme inactivation, and juice yield enhancement, these being radiation treatments (UV light, high-intensity light pulses, γ-irradiation), electrical treatments (pulsed electric fields, radiofrequency electric fields, ohmic heating), microwave heating, ultrasound, high hydrostatic pressure, inert gas treatments (supercritical carbon dioxide, ozonation), and flash-vacuum expansion. The nonthermal technologies discussed in this review have the potential to meet industry and consumer expectations. However, the lack of standardization in operating conditions hampers comparisons among different studies, and consequently ambiguity arises within the literature. For the juice industry to advance, more detailed studies are needed on the scaling-up, process design, and optimization, as well as on the effect of such technologies on juice quality of juices in order to maximize their potential as alternative nonthermal technologies in fruit-juice processing.
Pressurized liquid extraction (PLE) is a clean and environmentally friendly alternative for the recovery of bioactive compounds from fruit by-products. Herein we focused on PLE for the extraction of bioactive compounds from pomegranate peel using a combination of pressurized water and ethanol. The main aim was to determine the optimal PLE conditions, i.e., ethanol percentage and process temperature, to obtain a pomegranate peel extract (PPE) with maximum total phenolic content (TPC), punicalagin content, and antimicrobial activity (AMA). The experimental design was conducted using a central composite design with axial points. Response surface methodology was applied to optimize the response variables using the desirability function. Multiple response optimization indicated a process temperature of 200 °C and ethanol of 77% as optimal conditions. The TPC and the punicalagin content of PPE-PLE obtained under optimal conditions were 164.3 ± 10.7 mg GAE/g DW and 17 ± 3.6 mg/g DW, respectively. Our findings support the efficacy of PLE on TPC recovery but not in punicalagin recovery. The AMA against S. aureus was 14 mm. The efficacy of PPE-PLE in food applications must continue to be studied in order to achieve adequate information on its potential for developing new food additives.