The by-products of grapes (Vitis vinifera L.) in the winemaking process present a diverse phytochemical profile of (poly)phenols, essentially represented by phenolic acids, flavonoids, and stilbenes, which have health benefits. In winemaking, solid (grape stems and pomace) and semisolid (wine lees) by-products are generated, negatively impacting the sustainability of the agro-food activity and the local environment. Although information on the phytochemical profile of grape stems and pomace has been reported, especially information concerning (poly)phenols, research on wine lees is necessary to take advantage of the compositional traits of this residue. So, in the present work, an updated, in-depth comparison of the (poly)phenolic profiles of these three resulting matrices in the agro-food industry has been carried out to provide new knowledge and interesting data on the action of yeast and lactic acid bacteria (LAB) metabolism in the diversification of phenolic composition; additionally, we extract complementarities for the possible joint application of the three residues. The phytochemical analysis of the extracts was carried out using HPLC-PDA-ESI-MSn. The (poly)phenolic profiles of the residues showed significant discrepancies. The results obtained showed that the greatest diversity of (poly)phenols was found in the stems of the grapes, followed closely by the lees. Through technological insights, it has been suggested that yeasts and LAB, responsible for the fermentation of must, might play a key role in the transformation of phenolic compounds. This would provide new molecules with specific bioavailability and bioactivity features, which might interact with different molecular targets and, consequently, improve the biological potential of these underexploited residues.

Rocket salad is an important vegetable for the ready-to-eat sector, normally cultivated under greenhouse conditions, either in soil or soilless systems. In the latter case, as well as in the nurseries, its cultivation is usually carried out by using peat as a growing medium—a non-renewable substrate—for which it is urgent to find a replacement. Similarly to peat, compost may be used as a growing medium; however, depending on its origin, the chemical and physical characteristics may not bet suitable for plants’ cultivation. In this study, we propose the use of agro-industrial compost as a substitute for peat for rocket salad cultivation. Plants grown in compost, alone or in combination with the second cut of rocket salad, gave better results in several biometric parameters, without negatively affecting yield and dry weight percentage. As a mechanistic approach to further understand how compost can affect plants’ stress, the qualitative profile of phytochemicals (glucosinolates and (poly)phenols)—recognized markers of biotic and abiotic plant stress—were monitored and exhibited a decreasing trend in plants grown using compost relative to those cultivated with peat. The analysis of vitamin C provided information on the achievement of an enhanced concentration by the compost, especially in the second cut. It can be inferred from the results obtained that the compost used as a growing medium may be used as a peat-free substrate for rocket crop cultivation.

Broccoli (Brassica oleracea var. italica) stalks account for up to 35% of the broccoli harvest remains with the concomitant generation of unused waste that needs recovery to contribute to the sustainability of the system. However, due to its phytochemical composition, rich in bioactive (poly)phenols and glucosinolates, as well as other nutrients, the development of valorization alternatives as a source of functional ingredients must be considered. In this situation, the present work aims to develop/obtain a new ingredient rich in bioactive compounds from broccoli, stabilizing them and reducing their degradation to further guarantee a high bioaccessibility, which has also been studied. The phytochemical profile of lyophilized and thermally treated (low-temperature and descending gradient temperature treatments), together with the digested materials (simulated static in vitro digestion) were analysed by HPLC-PDA-ESI-MSn and UHPLC-3Q-MS/MS. Broccoli stalks and co-products were featured by containing phenolic compounds (mainly hydroxycinnamic acid derivatives and glycosylated flavonols) and glucosinolates. The highest content of organosulfur compounds corresponding to the cores of the broccoli stalks treated by applying a drying descendant temperature gradient (aliphatic 18.05 g/kg dw and indolic 1.61 g/kg dw, on average, while the breakdown products were more abundant in the bark ongoing low temperature drying 11.29 g/kg dw, on average). On the other hand, for phenolics, feruloylquinic, and sinapoylquinic acid derivatives of complete broccoli stalk and bark, were more abundant when applying low-temperature drying (14.48 and 28.22 g/kg dw, on average, respectively), while higher concentrations were found in the core treated with decreasing temperature gradients (9.99 and 26.26 g/kg dw, on average, respectively). When analysing the bioaccessibility of these compounds, it was found that low-temperature stabilization of the core samples provided the material with the highest content of bioactives including antioxidant phenolics (13.6 and 33.9 g/kg dw of feruloylquinic and sinapoylquinic acids, on average, respectively) and sulforaphane (4.1 g/kg dw, on average). These processing options enabled us to obtain a new product or ingredient rich in bioactive and bioaccessible compounds based on broccoli stalks with the potential for antioxidant and anti-inflammatory capacities of interest.

Carob (Ceratonia siliqua L.) is an underutilized traditional crop in the Mediterranean regions that has gained much interest due to its high nutritional traits and resilience to drought and salinity. However, conventional methods of carob propagation are not enough to meet its increasing market demands. The present study analyzes to what extent benzyl adenine (BA) treatments (0.1, 0.5 and 1.0 mg L−1) alone or in combination with UV-C irradiation (3.34 and 10.01 kJ m−2) affect the antioxidant capacity and the levels of phenolic compounds in in vitro carob shoot cultures as well as their performance in terms of the content of photosynthetic pigments and sugars. Results showed that the combination of both treatments resulted in an increased content of chlorophylls, carotenoids, and sugars, particularly at 0.5 mg L−1 BA and the highest UV-C dose. Antioxidant capacity, assessed by the DPPH method, and the levels of soluble flavonoids, flavones and flavonols, and hydroxycinnamic acids were highly influenced by the interaction between BA and UV-C in the combined treatments. This indicates a clear dependence on BA concentration in the response of carob in vitro shoots to UV-C. This could be the basis for the implementation of more efficient carob micropropagation processes.