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Research background. Soursop nectar contains antioxidants and is preserved by pasteurization. However, this technology impairs its physicochemical properties and bioactive compounds. An alternative is therefore thermoultrasound, which could counteract these effects. The thermosonicated nectar was compared with a pasteurized one and the in vitro bioaccessibility of antioxidants was estimated. Experimental approach. The soursop nectar (25 %) was processed and the response surface methodology was used to determine the optimal conditions for thermoultrasound treatment (TUS). The TUS (75-90 % amplitude, 3.15-15 min) was applied, and 2 % stevia and 6 % agave inulin were added as sweeteners. The microbiological, physicochemical, enzymatic and antioxidant properties were analyzed. The properties of thermosonicated nectar obtained under optimal conditions were compared with pasteurized nectar. In addition to the above determinations, microstructure, total dietary fiber (TDF) and in vitro bioaccessibility of antioxidants were determined. Results and conclusions. The response variables that fit the mathematical model were L*, b*, chroma (C*), total phenolic content (TPC) and antioxidant activity determined by ABTS•+, DPPH˙ and Fe(III) reducing antioxidant power (FRAP). The L* and DPPH˙ were affected by quadratic time and TPC by time (p<0.0001). The optimum TUS condition was 82 % amplitude for 9.15 min and the responses variables were L*, b* and C* (45.48, 3.55 and 3.62, respectively), TPC expressed as gallic acid equivalents (38.40 mg/100 mL), ABTS•+ expressed as Trolox equivalents (TE) (31.28 μmol/100 mL), DPPH˙ expressed as TE (124.22 μmol/100 mL) and FRAP expressed as Fe(II) (3.06 μmol/100 mL). Compared to the pasteurized sample, thermosonicated sample had high values of L* (45.56), h° (-56.49), TPC (26.63 mg/100 mL), ABTS•+ and DPPH˙ (22.03 and 129.22 μmol/100 mL, respectively), FRAP (3.10 μmol/100 mL) and low pectin methylesterase (PME) activity (0.28 U/mL). For in vitro bioaccessibility, thermosonicated nectar showed high absorption of TPC (15.26/100 mL) and high antioxidant activity determined by ABTS (34.92 μmol/100 mL) and FRAP (7.88 μmol/100 mL). Novelty and scientific contribution. The thermoultrasound improves the physicochemical properties and in vitro bioaccessibility of antioxidants in soursop nectar. On the other hand, as an alternative, this beverage offers low-calorie alternative with prebiotic properties that benefits consumer health. [ABSTRACT FROM AUTHOR]

Functional beverages market requires conservation methods where bioactive compounds could persist for their bioavailability. The aim of this work was determined the extraction yield, antioxidant capacity and bioaccessibility of a cactus pear (Opuntia ficus-indica) juice blended using different solvent to extraction after pasteurization (PAST) or thermoultrasonication (TUS) treatment. The best properties were exhibited by TUS juice, showing 575.8 ± 11.1 mg GAE·L-1 for total phenolic, and 392.78 ± 4.1 mg BE·L-1 for pigment content. Which resulted in a greater antioxidant activity bioaccessible (87% DPPH; 38% ABTS). The highest antioxidant activity was found in the TUS methanolic extraction, exhibiting higher bioaccessibility than the juice (78% ABTS; 179% DPPH). It can be concluded that thermoultrasonication and methanolic extraction of a cactus pear juice blend allows a higher amount of antioxidant compounds to be bioavailable. [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the capsaicin (CAP) and dihydrocapsaicin (DHC), total phenolic content (TPC) as well as antioxidants properties of Habanero pepper (Capsicum chinense Jacq.) oleoresin (HPO) during storage. Identification and quantification of CAP and DHC were performed by HPLC, while TPC and antioxidant activity by ABTS and DPPH were by spectrophotometry. Retention time of CAP and DHC was 19.23 and 20.47 min, respectively. During storage, CAP and TPC remained stable until day 35 (14.35 to 15.72 mg CAP/g HPO and 29.13 to 28.31 mg GAE/mL HOP, respectively), while DHC had similar values (11.45 - 9.61 mg CAP/g HPO) (p>0.05) through storage time. On the other hand, antioxidant activity by ABTS and DPPH decreased from day 15 (6.08 µmol TE/mL) and 35 (10.18 µmol TE/mL), respectively. The results showed that CAP, DCH and TP were stable for more than a month of storage. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the optimal thermoultrasound processing conditions for jackfruit nectar by applying response surface methodology and comparing the physicochemical parameters, antioxidant properties, microbiology, and fatty acid profile with pasteurized jackfruit nectar. Optimal condition was 80% of amplitude at 45 ± 1°C for 20 ± 1 min, allowing physical stability of 68%, 60% of pectin methylesterase activity, ascorbic acid of 420 mg AA/L, total phenolic of 134 mg GAE/L, ABTS, DPPH, and chelating activity of 3,510 µmol TE/L, 75 µmol TE/L, and 96%, respectively. The thermoultrasonicated jackfruit nectar had lower microbial load and higher total soluble solids, ascorbic acid content, total phenolic content, antioxidant activity than pasteurized, and similar unsaturated fatty acids to the untreated sample. Our results demonstrated that thermoultrasound could be an option for processing jackfruit nectar as an alternative to pasteurization that allows successful inactivation of microorganisms, inactivation of enzymes, and good quality parameters. Practical applications: Based on consumer demand for more natural or fresh‐like products, alternative technologies have been evaluated by research works looking to reduce the effects of heat treatments in the Food Industry. Among these technologies, thermoultrasound technology have gained relevance and seems to be a good replacement to inactivate microorganisms and enzymes without affecting the quality parameters, maintaining the unsaturated fatty acids content, and even increasing bioactive compounds. For example, the thermoultrasound application in jackfruit nectar has been demonstrated as a viable preservation technique to develop an innocuous nectar without affecting their food quality. Nevertheless, in order to solve the challenges about potential applications of ultrasound technology, further research is needed to obtain optimal processing conditions according to the food matrix quality required. [ABSTRACT FROM AUTHOR]