Juana M. Carbonell-Capella

Analytical Methods for Determining Bioavailability and Bioaccessibility of Bioactive Compounds from Fruits and Vegetables: A Review

Determination of bioactive compounds content directly from foodstuff is not enough for the prediction of potential in vivo effects, as metabolites reaching the blood system may be different from the original compounds found in food, as a result of an intensive metabolism that takes place during absorption. Nutritional efficacy of food products may be ensured by the determination of bioaccessibility, which provides valuable information in order to select the appropriate dosage and source of food matrices. However, between all the methods available, there is a need to establish the best approach for the assessment of specific compounds. Comparison between in vivo and in vitro procedures used to determine bioaccessibility and bioavailability is carried out, taking into account the strengths and limitations of each experimental technique, along with an intensive description of actual approaches applied to assess bioaccessibility of bioactive compounds. Applications of these methods for specific bioactive compounds bioaccessibility or bioavailability are also discussed, considering studies regarding the bioavailability of carotenoids, polyphenolic compounds, glucosinolates, vitamin E, and phytosterols.

Effect of Stevia rebaudiana addition on bioaccessibility of bioactive compounds and antioxidant activity of beverages based on exotic fruits mixed with oat following simulated human digestion.

In order to determine the impact of Stevia rebaudiana (SR) addition on bioactive compounds bioaccessibility of a new developed functional beverage based on exotic fruits (mango juice, papaya juice and açaí) mixed with orange juice and oat, an in vitro gastrointestinal digestion was performed. Ascorbic acid, total carotenoids, total phenolics, total anthocyanins, total antioxidant capacity and steviol glycosides were evaluated before and after a simulated gastrointestinal digestion. Salivary and gastric digestion had no substantial effect on any of the major phenolic compounds, ascorbic acid, total antioxidant capacity and steviol glycosides, whereas carotenoids and anthocyanins diminished significantly during the gastric step. All analysed compounds were significantly altered during the pancreatic-bile digestion and this effect was more marked for carotenoids and total anthocyanins. However, phenolic compounds, anthocyanins, total antioxidant capacity and steviol glycosides bioaccessibility increased as did SR concentration. Ascorbic acid bioaccessibility was negatively affected by the SR addition.

Quality parameters, bioactive compounds and their correlation with antioxidant capacity of commercial fruit-based baby foods

Comprehensive research is required to achieve the optimization of the antioxidant protection through baby foods, in particular, the commercially available fruit-based baby foods. This study investigated the physicochemical properties, ascorbic acid (AA), total carotenoids (TC), total phenolic content (TPC), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) of 23 different commercially available fruit-based baby foods. The main contribution to the total antioxidant capacity (trolox equivalent antioxidant capacity and oxygen radical absorbance capacity) was provided by ascorbic acid, followed by phenolic compounds, in accordance with a mathematical equation obtained from the data: TEAC = 245.906 + 7.727 × (AA) + 1.988 × (TPC) − 0.008 × (TC) and ORAC = 318.662 + 2.775 × (AA) − 0.531 × (TPC) − 0.073 × (TC). Moreover, a positive correlation (r = 0.346, p < 0.05) was found for oxygen radical absorbance capacity and trolox equivalent antioxidant capacity methods. Baby foods with different kind of fruits used as ingredients showed higher antioxidant capacity. Among the commercial baby foods analysed in this work, that treated by gentle steam cooking process had high levels of bioactive compounds and antioxidant capacity.

Bioaccessibility of bioactive compounds after non-thermal processing of an exotic fruit juice blend sweetened with Stevia rebaudiana

A comparative study of the bioaccessibility of bioactive compounds and antioxidant capacity in a fruit juice-Stevia rebaudiana mixture processed by pulsed electric fields (PEF), high voltage electrical discharges (HVED) and ultrasound (USN) technology at two equivalent energy inputs (32-256kJ/kg) was made using an in vitro model. Ascorbic acid was not detected following intestinal digestion, while HVED, PEF and USN treatments increased total carotenoid bioaccessibility. HVED at an energy input of 32kJ/kg improved bioaccessibility of phenolic compounds (34.2%), anthocyanins (31.0%) and antioxidant capacity (35.8%, 29.1%, 31.9%, for TEAC, ORAC and DPPH assay, respectively) compared to untreated sample. This was also observed for PEF treated samples at an energy input of 256kJ/kg (37.0%, 15.6%, 29.4%, 26.5%, 23.5% for phenolics, anthocyanins, and antioxidant capacity using TEAC, ORAC and DPPH method, respectively). Consequently, pulsed electric technologies (HVED and PEF) show good prospects for enhanced bioaccessibility of compounds with putative health benefit.

Steviol Glycosides Stability after Pulsed Electric Technologies and Ultrasounds Treatments in Fruit Juice Blend Sweetened with Stevia rebaudiana

Stevia rebaudiana bartoni due to its high content in steviol glycosides and the ability to serve as a natural antimicrobial to complement the effectiveness of pulsed electric technologies for food preservation, has been used more frequently to improve sensorial properties of liquid foods.

Pulsed Electric Field Processing Optimization of Ascorbic Acid in a Mango and Papaya Beverage Sweetened with Stevia Rebaudiana

During the processing of liquid foods, ascorbic acid may be altered, thus reducing beneficial health effects. For this reason, the degradation kinetics of ascorbic acid were determined in a fruit juice mixture (papaya and mango) sweetened with Stevia rebaudiana (SR) infusion after treatment by pulsed electric field (PEF) processing. The variable ranges were 20-40 kV/cm (electric field strength, E) during 100-360 μs (time treatment, t). The degradation equation was AA (mg/100 mL) = 26.842 - 0.101·E - 0.003·t- 10.371·%Stevia + 2.865·%Stevia2, demonstrating the use of PEF as an alternative to pasteurization treatments. However, results show the need to optimize treatment conditions whenever there is a change in the matrix (food) or some processing factor.

IMPACT OF ELECTROTECHNOLOGIES AND ULTRASOUND TREATMENT IN THE FLAVONOIDS PROFILE OF A PAPAYA, MANGO AND STEVIA REBAUDIANA BEVERAGE

A high content of flavonoids in beverages is desirable not only due to their beneficial health effects, but also due to their ability to protect fruit juices from oxidation. However, food processing has a profound effect on these phytochemicals, with the further loss of most of their beneficial properties. For this reason, five flavonoids (catechin, rutin, hesperidin, quercetin and apigenin) were analyzed by HPLC in accordance to Kelebek et al. (2015) in a fruit juice-stevia beverage before and after pulsed electric fields (PEF), high voltage electical discharges (HVED) and ultrasounds (USN) treatments at two equivalent energy inputs. Catechin and hesperidin were the mayor phenolic compounds. For this two flavonoids, along with quercetin, PEF and USN treatments resulted in a significant increase compared to untreated beverage. By contrast, rutin decreased after PEF, HVED and USN treatment. The highest decrease was obtained when the beverage was treated by HVED at 256 kJ/kg. Apigenin content was far much lower in the USN treated beverage, as this compound may be severely affected by the cavitation phenomena. Results obtained highlight that individual flavonoids undergo different changes immediately after HVED, PEF and USN treatments, whereas others remain unchanged or are even enhanced.