Nowadays, sweet potato (Ipomoea batata L.; Lam.) is considered a very interesting nutritive food because it is rich in complex carbohydrates, but as a tubercle, contains high amounts of health-promoting secondary metabolites. The aim of this review is to summarize the most recently published information on this root vegetable, focusing on its bioactive phytochemical constituents, potential effects on health, and the impact of processing technologies. Sweet potato is considered an excellent source of dietary carotenoids, and polysaccharides, whose health benefits include antioxidant, anti-inflammatory and hepatoprotective activity, cardiovascular protection, anticancer properties and improvement in neurological and memory capacity, metabolic disorders, and intestinal barrier function. Moreover, the purple sweet potato, due to its high anthocyanin content, represents a unique food option for consumers, as well as a potential source of functional ingredients for healthy food products. In this context, the effects of commercial processing and domestic cooking techniques on sweet potato bioactive compounds require further study to understand how to minimize their loss.

The challenge of sustainable agriculture is to increase yields and obtain higher quality products. Increased antioxidant compounds such as polyphenols in harvest products may be an added value for sustainable agriculture. The aim of the present study was to investigate whether three organic fertilization treatments with different levels of carbon and nitrogen, i.e., N-rich, N-rich+C, and N-poor+C, affected the phenolic content of different tomato varieties. The examined parameters were productivity, plant nutritional status, δ¹³C, and tomato phenolic content as an indication of the antioxidant capacity. The best production was obtained with ‘Cornabel’, a high-yielding Pebroter variety. The total phenolic content was highest in the traditional ‘Cuban Pepper’ variety regardless of treatment, while naringenin levels were high in all the Pebroter varieties. In N-poor+C fertilized plants, a lower N-NO₃ content in leaves was correlated with higher levels of total polyphenols in the fruit. The high-water stress suffered by Montserrat varieties coincided with a low total phenolic content in the tomatoes. In conclusion, organic fertilization with reduced N did not influence the tomato yield but positively affected phenolic compound levels in varieties less sensitive to water stress.

Tomatoes are among the most consumed vegetables within the Mediterranean diet, recognized as one of the healthiest dietary patterns in the world. This study evaluated the effects of four fertilization treatments on the antioxidant and metabolic profiles of four local tomato varieties: Cornabel (V1), Cuban Pepper (V2), Corno Andino (V3), and Roli Rosa (V4). Treatment 1 (T1) used 1.28 kg/m² of commercial woody compost (C/N ratio 13), while Treatment 2 (T2) served as the control, initially without fertilization. Treatments 3 and 4 (T3, T4) incorporated ramial chipped wood (RCW) at 15 kg/m² and 7.5 kg/m², respectively, without tillage. Each treatment × variety combination included four biological replicates (n = 4). Untargeted metabolomic profiling via UHPLC-QToF and statistical analyses identified 163 compounds, 37 of which showed significant varietal differences (p < 0.05). The flavonoid eriodictyol was more abundant in the Pebroter varieties (V1, V2, V3), whereas luteolin-8-O-glucoside (orientin) predominated in V4, likely due to differential expression of biosynthetic genes. RCW (T3) yielded higher levels of antioxidant compounds like phenolic acids, and flavonoids compared to compost and control; however, no dose–response was observed using different doses of RCW (T3 and T4). These findings demonstrate that RCW may modulate the antioxidant metabolite profile of tomatoes, highlighting its potential as a sustainable fertilization strategy for enhancing antioxidant compounds.

Soil management practices have led to a generalized decarbonization of agricultural soils' organic matter and carbon contents. Whereas mulching application of large amounts of organic matter (OM) on the soil surface, the incorporation of massive amounts of organic matter into the soil profile (e.g. 40-120 m3 ha-1) has been much less common, and has only been studied in a limited capacity, with effects varying depending on soil type, climate and origin of the incorporated lignocellulosic material. Large amounts of carboniferous materials applied to soil can provoke nutritional disequilibria, and potential nutritional deficiencies for plants. However, it has been shown that sweet potato (Ipomea batatas) may be able to overcome N limitation, though the exact mechanism is not clear. In a field experiment in Catalonia, we applied an equivalent of 150 t ha-1 ramial chipped wood (RCW) simultaneously with sweet potato cultivation. The experiment was set up in two adjacent in arable fields with a cold semi-arid climate (yearly precipitation ~ 400 mm) with contrasting previous management: one field had been abandoned for 15 years, while the other had been managed with regenerative farming techniques including organic manure application, limited tillage, and green cover since 2006. RCW was applied in March, sweet potato was planted in May, and the plants were harvested in October. Using a combination of techniques including mass balances of C and N in fine earth and large (> 2 mm) organic fractions, plant nutritional analysis, and 15N stable isotope natural abundance method, we examined C and N dynamics in the soil and plant nutrition. RCW incorporation increased both C and N in the plots where applied (Figure). However, absolute and relative gains were much greater in the regenerated plots, and the recovered C and N was much greater in the regenerated plots. Sweet potato N nutrition was not seen to be influenced by soil chemical properties (N fractions), pointing to other non-identified nutrition sources. Sweet potato leaf 𝛿15N also changed dramatically between samplings (March and October), indicating a change in N source. These first results give some indications about the potential for rapid soil recarbonization in soils under different management and crop appropriateness to make this transition.