No abstract

Ultrasonic-assisted extraction (UAE) of the oil from the seeds/peel mixture of pumpkin using ethanol as solvent was investigated. The effects of the ultrasound, solvent volume, time, and temperature on the oil yield were evaluated. Oil extraction from the seeds by ultrasound and the mixture by Soxhlet extraction (SE) was also performed. The use of ultrasound and higher availability of ethanol (up to 6 mL g −1 sample) favored the oil removal. In the extraction kinetics, the washing step was verified in the first 20 min, corresponding to 79-89% of the total oil yield. The diffusion coefficient increased from 30 to 75 C, as well as the spontaneity of the extraction, achieving 71% of the SE. Linoleic and oleic acids were found in higher concentrations in the oils. UAE made possible the greater extraction of β-carotene, tocopherols, and fistosterois, and the peel addition provided higher contents of these compounds.

This study investigated the extraction of betalains from red beet by an ultrasoundassisted process using water as solvent. For this purpose, the effect of time and temperature on ultrasound-assisted extraction (UAE) was evaluated, and together the effect of ultrasound on the process was investigated by comparing the results with orbital shaking extraction (OSE). From the ideal conditions of these parameters, defined in the UAE, the effects of the ultrasound power and the solvent/sample ratio were evaluated and the experimental data obtained in the kinetics with different solvent/sample ratios were correlated with the diffusion coefficient of betalain in water. The results showed that the betalains content present in the extract decreased with temperature and the same occurred with the increase in time at higher temperatures, therefore, 30°C and 30 min were the first conditions established. Under these conditions, the UAE showed better results in obtaining betalain compared to OSE. The increase in ultrasound power improved the extraction and 83 W was sufficient for maximum removal of the compounds. The highest betalains content was obtained using solvent/sample ratio of 75 ml/g and this result is attributed to the highest diffusion coefficients determined in this condition. This extract showed high sugar content, being sucrose the main component (~96%), and also exhibits high antioxidant activity by ABTS, DPPH, and FRAP methods.

The objective of this work was to evaluate the efficacy of ethyl acetate as a solvent in the extraction of macauba kernel oil (MKO) using ultrasonic-assisted extraction (UAE). It was shown that more MKO oil could be extracted with the use of larger amounts of solvent, higher temperatures and longer extraction times. Thus the maximum oil yield (40.61%) was obtained by UAE at 60 °C for 45 min, using a solvent to kernel ratio of 12 (mL g-1), obtaining a higher yield than that obtained with n-hexane under the same experimental conditions. UAE was favorable for this oil extraction (p < 0.05), presenting a yield close to that reported for classical extraction but with a shorter extraction time and smaller solvent volume. Lauric acid corresponded to ~44% of the MKO composition. The oils presented low free fatty acid contents (<0.80% wt), and the phytosterols, campesterol and β-sitosterol, were identified in the MKO with higher levels in the oil obtained by UAE.

The aim of this study was to evaluate the effect of hydrolysate collagen (HC), cheese whey (CW), and açaí pulp (AP) content on the characteristics of probiotic dairy beverages. Higher levels of CW and AP decreased beverage ash and protein content, and increased lipid and carbohydrate content and energy values. HC and AP positively affected the viscosity of the formulations, which exhibited pseudoplastic behavior. In terms of quality parameters, higher levels of CW and AP increased both the syneresis (2.56–5.74%) and sedimentation index values (1.80–1.87%) of the formulations. The beverages presented adequate stability of physicochemical and microbiological parameters during 28 days storage. Formulations containing average levels of CW (22.5%), AP (30%), and HC (1.0%) achieved the best results regarding sensory analysis, with acceptability index values above 70% for most parameters. Practical applications Demand for probiotic foods is currently increasing due to their potential health benefits. Although the utilization of cheese whey in dairy beverage development is a challenge to the food industry because of the viscosity of the final product, this situation can be improved via the use of selected ingredients. Açaí pulp, hydrolyzed collagen, and cheese whey, when used in the production of probiotic dairy beverages, offer to the market a new functional product of adequate quality and acceptability.

In this article, the enzymatic aqueous extraction (EAE) of sunflower seed oil was investigated. The effects of the operational variables (temperature, water seed mass ratio, and enzyme concentration) were evaluated in order to define the conditions that maximize the free oil yield (FOY). It was observed that increasing the amounts of water and enzyme in the extraction medium was disadvantageous to the removal of the oil, and that an increase in temperature provided a higher FOY. Thus, a temperature of 60°C, seed:water ratio of 1:5 (g/g), and enzyme concentration of 1% (v/v) were defined as the conditions for maximum FOY (17.76%). The use of a buffered medium under these conditions increased the FOY to 20.34%. The composition of the oils obtained by the EAE under different experimental conditions was determined and compared with the oil obtained from Soxhlet extraction. The oils under study presented high levels of oleic and linoleic acids, which corresponded to ~90% of the composition of fatty acids. It was also noted that, depending on the extraction conditions, the oils obtained by EAE presented phytosterol and tocopherol contents similar or superior to those of the oil produced by Soxhlet extraction. Practical Applications The enzymatic aqueous extraction of sunflower oil has the potential to replace the solvent extraction method. The results reported herein show that the composition of the sunflower oil obtained by the enzymatic method was similar to that of the oil extracted by the solvent method. In addition, the enzymatic method uses mild conditions that reduce the energy required for the process and the residues are free of organic solvent.

The aim of this work was to investigate the ultrasound‐assisted extraction (UAE) of total phenolic compounds (TPC) and soluble sugars (SS) from the by‐product of peach palm (stem portion). The effect of the processing variables temperature (30–60°C), time (15–45 min), and power density (8.47–25.42 mW cm−3) were evaluated. The maximum contents (dry basis) of TPC (345.81 ± 2.82 mg gallic acid equivalent 100 g−1) and SS (16.68 ± 0.24 g 100 g−1) were obtained, respectively, at 60°C, 30 min and 8.47 mW cm−3 (condition 1) and 60°C, 45 min and 25.42 mW cm−3; in these conditions, the extracts had higher sucrose content than glucose and fructose. The highest content of phenolic acids (gallic, coumaric, vanillic, ferulic, trans‐cinnamic) and highest antioxidant activity were obtained in the condition 1. UAE can be considered an effective method for the extraction of TPC and SS from peach palm stem. Practical applications The ultrasound‐assisted extraction (UAE) was applied in the by‐product of heart‐of‐palm (stem portion) to the removal of phenolic compounds and soluble sugars. To realize this process with time and energy economy, the maximized condition of extraction observed at 60°C, 30 min, and 8.47 mW cm−3 was the most interesting. This extract showed the highest content of phenolic compounds and highest antioxidant potential, which can allow its application to preserve the shelf life of food products or to produce food supplements. The soluble sugars extracted can also be used, as example, in fermentative process. Therefore, the results indicate the viability of UAE to offer alternatives to utilization of stem portion of peach palm.

The objective of this study was to maximize the ultrasonic‐assisted extraction (UAE) of β‐carotene for sunflower oil, by adjusting the combinations of the operational variables: temperature, time, and oil to carrot ratio, as well as obtaining extraction kinetics. Enriched sunflower oil and commercial sunflower oil was characterized. A polynomial model was developed to describe the β‐carotene content as a function of operating parameters and the results indicated that all variables had an influence on the β‐carotene extraction. The maximum values of temperature (55°C), time (60 min), and oil to carrot ratio (30 ml/g) promoted the highest removal of β‐carotene. UAE was endothermic, irreversible, and the increase in temperature favored the viability and spontaneity of the process. The oils presented linoleic and oleic acid as the main fatty acids and the enrichment of sunflower oil did not affect the fatty acid profile and the contents of phytosterols and tocopherols. Practical applications The demand for functional foods and the minimization of synthetic additives have stimulated the application of natural active compounds to products, such as β‐carotene, which is known for its antioxidant properties. To investigate the extraction of β‐carotene, it is important to use efficient technologies that maintain the characteristics of the extract and that overcome the disadvantages of conventional techniques, such as longer extraction time and high solvent consumption. In this context, the enrichment of the sunflower oil with β‐carotene from the ultrasound‐assisted extraction is highlighted. In addition, optimization studies and thermodynamic analysis contribute to the improvement in the process performance, through the systematic selection of the operational variables, and to the understanding of the behavior of the active compound with the interfaces of the extraction, respectively.