Enrichment and preservation of a vegetable smoothie with an antioxidant and antimicrobial extract obtained from beet by-products

This study aims to assess beet leaves extracts (BLE) potential for fruit and vegetable smoothie enrichment and/or preservation. BLE presented a total phenolic content (TPC: 132.43 ± 1.51 g kg−1 dry weight (DW) basis) and an antioxidant capacity (219.2 ± 23.4 mmol kg−1 DW for FRAP and 28.9 ± 0.5 mmol kg−1 DW for DPPH). An antimicrobial activity assay proved BLE effectiveness against Listeria innocua, E. coli and Saccharomyces cerevisiae on systems of pH 3.7 and 7, with initial counts of 4 or 7 log CFU/mL. Incorporation of the BLE into a fruit and vegetable (F&V) smoothie containing orange juice (59%), apples (15%), carrots (15%), BL (6%) and beet stems (5%), significantly increased (50%) TPC of the product as well as their antioxidant capacity. Additionally, extract-enriched smoothies achieved reductions between of 1–3 log cycles in smoothie's native microflora allowing to obtain a one-week shelf-life extension, and presented greater nutritional retention during storage at 5 °C. Therefore, BLE has great potential to be used for the enrichment and preservation of smoothies, bringing great advantages for food industry, consumers and producers.Fil: Fernandez, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Bengardino, Macarena. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química; ArgentinaFil: Jagus, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Agüero, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentin

Recovery of bioactive compounds from beet leaves through simultaneous extraction: Modelling and process optimization

Extraction of bioactive compounds from beet leaves was studied for the valorization of this by-product. The objective of this work was to optimize the extraction of total phenolic compounds (TPC), betacyanins (BC) and betaxanthins (BX) from beet leaves through a liquid:solid process with low environmental impact. For this propose, kinetic aspects of the extraction process at 30 and 80 °C were evaluated, finding that times higher than 60 min were unfavourable for betalainic pigments since degradation was observed. Thereafter a Plackett–Burman design was applied to study the effect of several extraction variables on the efficiency of the process. Accordingly, temperature, %EtOH and solid:liquid ratio were selected as the most significant variables for a further optimization. Finally, Response Surface Methodology was employed in order to simultaneously maximize the three responses. The extraction conditions that achieve this goal were: 61 °C, 80% EtOH and r of 1:10, under which the bioactive concentrations were: 31.7 mg AG/g DM, 0.78 mg/g DM, 2.17 mg/g DM for TPC, BC and BX, respectively. The study proposes a simple and reasonably efficient method to produce a rich in phenolics, bright red–purple extract, which can be later processed to be used in several applications for the food industry.Fil: Bengardino, Macarena. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química; ArgentinaFil: Fernandez, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Nutter, Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Jagus, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; ArgentinaFil: Agüero, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentin