RESUMO
The objective of this work was to gain insight into the operating conditions that affect the efficiency of ultrasound-assisted extraction (UAE) parameters to achieve the best recovery of bioactive compounds from broccoli leaf and floret byproducts. Therefore, total phenolic content (TPC) and the main sulfur bioactive compounds (sulforaphane (SFN) and glucosinolates (GLSs)) were assayed. Distilled water was used as solvent. For each byproduct type, solid/liquid ratio (1:25 and 2:25 g/mL), temperature (25, 40, and 55 °C), and extraction time (2.5, 5, 7.5, 10, 15, and 20 min) were the studied variables to optimize the UAE process by using a kinetic and a cubic regression model. TPC was 12.5-fold higher in broccoli leaves than in florets, while SFN was from 2.5- to 4.5-fold higher in florets regarding the leaf's extracts obtained from the same plants, their precursors (GLS) being in similar amounts for both plant tissues. The most efficient extraction conditions were at 25 °C, ratio 2:25, and during 15 or 20 min according to the target phytochemical to extract. In conclusion, the type of plant tissue and used ratio significantly influenced the extraction of bioactive compounds, the most efficient UAE parameters being those with lower energy consumption.
RESUMO
Vegetable beverages are a convenient strategy to enhance the consumption of horticultural commodities, with the possibility of being fortified with plant by-products to increase functional quality. The main objective was to develop a new veggie beverage from broccoli stalks and carrot by-products seasoned with natural antioxidants and antimicrobial ingredients. Pasteurization, Ultrasound (US), and High Hydrostatic Pressure (HHP) and their combinations were used as processing treatments, while no treatment was used as a control (CTRL). A shelf-life study of 28 days at 4 °C was assayed. Microbial load, antioxidant capacity, and bioactive compounds were periodically measured. Non-thermal treatments have successfully preserved antioxidants (~6 mg/L ΣCarotenoids) and sulfur compounds (~1.25 g/L ΣGlucosinolates and ~5.5 mg/L sulforaphane) throughout the refrigerated storage, with a longer shelf life compared to a pasteurized beverage. Total vial count was reduced by 1.5-2 log CFU/mL at day 0 and by 6 log CFU/mL at the end of the storage in HHP treatments. Thus, the product developed in this study could help increase the daily intake of glucosinolates and carotenoids. These beverages can be a good strategy to revitalize broccoli and carrot by-products with high nutritional potential while maintaining a pleasant sensory perception for the final consumer.
RESUMO
Food losses and waste reduction are a worldwide challenge involving governments, researchers, and food industries. Therefore, by-product revalorization and the use of key extracted biocompounds to fortify innovative foods seems an interesting challenge to afford. The aim of this review is to evaluate and elucidate the scientific evidence on the use of green technologies to extract bioactive compounds from Brassica by-products with potential application in developing new foods. Scopus was used to search for indexed studies in JCR-ISI journals, while books, reviews, and non-indexed JCR journals were excluded. Broccoli, kale, cauliflower, cabbage, mustard, and radish, among others, have been deeply reviewed. Ultrasound and microwave-assisted extraction have been mostly used, but there are relevant studies using enzymes, supercritical fluids, ultrafiltration, or pressurized liquids that report a great extraction effectiveness and efficiency. However, predictive models must be developed to optimize the extraction procedures. Extracted biocompounds can be used, free or encapsulated, to develop, reformulate, and/or fortify new foods as a good tool to enhance healthiness while preserving their quality (nutritional, functional, and sensory) and safety. In the age of recycling and energy saving, more studies must evaluate the efficiency of the processes, the cost, and the environmental impact leading to the production of new foods and the sustainable extraction of phytochemicals.