Six-month-old Eucalyptus globulus Labill. seedlings were grown in sand culture irrigated with a nutrient solution containing 6.0 mol N m(-3) for 3 months (November-January). Before rapid growth began in February, seedlings were repotted and irrigated with either 6.0 mol N m(-3) (High-N treatment) or 1.0 mol N m(-3) (Low-N treatment). Seedlings were analyzed during the subsequent flush of growth to determine the role of old leaves, and in particular the leaf protein Rubsico, as a source of N for new leaf growth. During spring growth, the N content of old leaves of High-N seedlings decreased with decreasing leaf dry weight, although there was no change in leaf number. In High-N seedlings, the net loss of N from old leaves provided less than 10% of the N used for new leaf growth, and the new leaves quickly became the dominant sink for N. In contrast, in Low-N seedlings, the net loss of N from old leaves provided 44% of the N used for new leaf growth. During the period of spring growth, the amount of soluble proteins recovered from old leaves of Low-N seedlings dropped, but there was no change in the content of either Rubisco or chlorophyll. The photosynthetic capacity of old leaves remained constant throughout the study period, and there was no evidence that N was remobilized from Rubisco.

Xique‐xique (Pilosocereus gounellei) considered an unconventional species, is a cactus popularly consumed by local populations of Semiarid Brazilian and the cladodes are used in food preparations. The objective of this study was to elaborate juice with cladodes xique‐xique and to characterize its nutritional composition, determine the bioaccessibility of phenolic compounds, and antioxidant activity. The juice presented relevant soluble fibers (0.55 g/100 ml) and minerals contents. Nineteen phenolics compounds were identified in xique‐xique juice. Flavanols were the major class of phenolic compounds with epigallocatechin gallate (14.52 mg/ml) and catechin (4.71 mg/ml). After the gastrointestinal digestion catechin (16.49%), epigallocatechin gallate (23%), procyanidin B1 (27.81%) and B2 (15.79%), gallic (50.74%), and caffeic (17%) acids were bioaccessible, demonstrating a strong correlation with high antioxidant activity by ORAC and FRAP assay. This research demonstrates xique‐xique juice is a new source of intake of minerals, fibers and phenolic compounds, and that it also aggregates value to an underexploited specie. Practical applications Xique‐xique (Pilosocereus gounellei) considered an unconventional species is a cactus popularly consumed by local populations of Semiarid Brazilian, and the cladodes are used in food preparations. Despite the widespread use of xique‐xique by the communities of the Brazilian semi‐arid region, still, there is no scientific data on the nutritional composition of xique‐xique cladode juice. The juice represents an alternative source for the consumption of fiber, minerals, and bioaccessible phenolic compounds, since it presents a variety of phenolic compounds that contribute to the antioxidant capacity. Furthermore, it can be used for application in the food industry in the manufacture of different drinks. The elaboration of products using unconventional food plants, rich in nutrients and bioactive compounds, could be a health benefit and add value to local resources.

Xique-xique (Pilosocereus gounellei) is a cactus found in the Caatinga biome which is used in folk medicine for treating inflammation, and also used in animal food. This study evaluated its proximate composition and bioactive compounds, as well as its bioaccessibility and antioxidant activity. Experiments were performed on different parts of the plant. The central stem of the xique-xique can be considered a source of insoluble dietary fiber (5.18 g/100 g) and soluble fiber (1.37 g/100 g). The vascular cylinder contained the highest mineral content: K (308.4 mg/100 g), Ca (145.57 mg/100 g), Mg (182.40 mg/100 g), and Mn (7.71 mg/100 g). The vascular cylinder group presented the highest activity for capturing DPPH radicals (572.96 µM of TEAC/100 g) and ferric reducing ability (1912.95 µM of TEAC/100 g). Catechin and epigallocatechin-gallate were the major phenolic compounds, while catechin, epigallocatechin gallate and procyanidin B and gallic acid were the most bioaccessible compounds after in vitro gastrointestinal digestion. Xique-xique can be considered as a potential food alternative with nutritional value and bioactive compounds, indicating its potential use and enrichment in various food products.

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