Effects of Post-Harvest Elicitor Treatments with Ultrasound, UV- and Photosynthetic Active Radiation on Polyphenols, Glucosinolates and Antioxidant Activity in A Waste Fraction of White Cabbage (Brassica oleracea var. capitata)

Post-Chromatographic Derivatization Coupled with Mass Spectrometry as a Method of Profiling and Identification of Antioxidants; Ligustrum vulgare Phytocomplex as an Example

High-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) coupled with radical scavenging assays, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) can be both used for the detection of the antioxidants in plant extracts. In this study, the ethanolic (70% v/v) extracts from different morphological parts of Ligustrum vulgare collected at different stages of maturity were used as the source of antioxidants. The final identification of antioxidants was performed using high-resolution mass spectroscopy (HRMS). As a result, 19 compounds with antioxidant properties detected with HPLC-ABTS assay and 10 compounds detected with HPTLC-DPPH/ABTS assay were identified, mostly from the group of iridoids, phenylethanoids, and flavonoids. When comparing different L. vulgare samples, it was found that the extracts obtained from leaves contained the greatest number of antioxidants. The results of this study suggest that HPTLC-DPPH/ABTS as well as HPLC-ABTS derivatization coupled with the HRMS can be successfully used for profiling and identification of antioxidants from natural sources. Planar chromatography is more suitable for screening multiple samples because of its simplicity, whereas more challenging liquid chromatography provides more detailed information and is therefore better for a selected set of samples.

Effect of Aloe vera gel coating on organoleptic and nutritional quality of minimally processed carrot

Demand for fresh vegetables has led to development studies in postharvest area mainly focused on minimizing and look for alternatives to chemical additives for food preservation. The use of natural derived edible coatings emerges as a promising alternative for maintaining quality of vegetables. The objective of this study was to evaluate the effect of Aloe vera gel in minimally processed carrot during postharvest storage. Samples with different degrees of processing were immersed in Aloe vera gel, packaged polyolefin bags, and stored in refrigerated chambers at 5 °C for 12 days. Different organoleptic and quality parameters were evaluated. In general, the samples treated with Aloe vera gel showed less quality loss and a lower increment in the bleaching index. Moreover, sensory analysis allowed to establish that carrots processed in slices and shredded and coated with the gel had a more flavorful taste and higher moisture content. Aloe vera treatment did not influence the microbiological growth of bacteria and fungi during storage. Regarding nutritional quality, the treated samples showed a higher accumulation or lower degradation of phenols, flavonoids, and carotenoids, probably generating in this way, a higher antioxidant capacity in these samples. Finally, Aloe vera gel treatment did not influence sugar dynamics in any of the samples. It can be concluded that the treatment with Aloe vera gel allows maintaining a better organoleptic and nutritional quality of carrots with different degrees of processing during refrigerated storage.

Genus Brassica By-Products Revalorization with Green Technologies to Fortify Innovative Foods: A Scoping Review

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.