Background and AimsRhizophora species of mangroves have a conspicuous system of stilt-like roots (rhizophores) that grow from the main stem and resemble flying buttresses. As such, the development of rhizophores can be predicted to be important for the effective transmission of dynamic loads from the top of the tree to the ground, especially where the substrate is unstable, as is often the case in the habitats where Rhizophora species typically grow. This study tests the hypothesis that rhizophore architecture in R. mangle co-varies with their proximity to the main stem, and with stem size and crown position. Methods The allometry and wood mechanical properties of R. mangle (red mangrove) trees growing in a mangrove basin forest within a coastal lagoon in Mexico were compared with those of coexisting, non-buttressed mangrove trees of Avicennia germinans. The anatomy of rhizophores was related to mechanical stress due to crown orientation (static load) and to prevailing winds (dynamic load) at the study site. Key Results Rhizophores buttressed between 10 and 33 % of tree height. There were significant and direct scaling relationships between the number, height and length of rhizophores vs. basal area, tree height and crown area. Wood mechanical resistance was significantly higher in the buttressed R. mangle (modulus of elasticity, MOE = 18·1 ± 2 GPa) than in A. germinans (MOE = 12·1 ± 0·5 GPa). Slenderness ratios (total height/stem diameter) were higher in R. mangle, but there were no interspecies differences in critical buckling height. When in proximity to the main stem, rhizophores had a lower length/height ratio, higher eccentricity and higher xylem/bark and pith proportions. However, there were no directional trends with regard to prevailing winds or tree leaning. Conclusions In comparison with A. germinans, a tree species with wide girth and flare at the base, R. mangle supports a thinner stem of higher mechanical resistance that is stabilized by rhizophores resembling flying buttresses. This provides a unique strategy to increase tree slenderness and height in the typically unstable substrate on which the trees grow, at a site that is subject to frequent storms.

The fatty acids profile and lipids content of the Macadamia integrifolia and Macadamia tetraphylla varieties and interspecies hybrids, M. integrifolia and M. tetraphylla were analyzed. Total lipids content ranged from 70.9 to 79.7 g of oil per 100 g⁻¹ dry-solids. Gas chromatography/mass spectrophotometry identified 20 fatty acids, the most abundant of which were oleic acid (40 to 51%), palmitoleic acid (24 to 36%), and palmitic acid (8.4 to 13.1%). Fatty acids concentration differed between varieties and hybrids (Multivariate analysis of variance, F = 13.89, p < 0.0001). A ratio of monounsaturated fatty acids:saturated fatty acid values ranged from 2.8 to 4.6. The Huatusco variety (M. integrifolia and M. tetraphylla) exhibited the highest percentage of lipids (79.7 g of oil per 100 g⁻¹ DS) and the highest monounsaturated fatty acids:saturated fatty acid (4.6), thus highlighted its potential applications within the food industry. The Cate variety (M. integrifolia and M. tetraphylla) had the lowest monounsaturated fatty acids:saturated fatty acid, suggesting potential uses in the cosmetics industry.

This study evaluated the impact of in vitro gastrointestinal digestion on the digestibility, amino acid release, and antioxidant activity of proteins from amaranth (Amarantus cruentus L.) and cañihua (Chenopodium pallidicaule Aellen). Antioxidant activity was assessed using ORAC, ABTS, DPPH, and cellular antioxidant activity (CAA) assays in human intestinal Caco-2 and hepatic Hep-G2 cell lines. The results showed that amaranth had higher protein digestibility (79.19%) than cañihua (71.22%). In addition, intestinal digestion promoted the release of essential amino acids, such as leucine, lysine, and phenylalanine, in both protein concentrates. Concentrations of amaranth and cañihua proteins, ranging from 0.125 to 1.0 mg mL⁻¹, were non-cytotoxic in both cell lines. At a concentration of 0.750 mg mL⁻¹, simulated gastrointestinal digestion enhanced cellular antioxidant activity. Intestinal digest fractions containing peptides >5 kDa were the principal contributors to CAA in both cell lines. Notably, cañihua proteins exhibited high CAA, reaching values of 85.55% and 82.57% in Caco-2 and HepG2 cells, respectively, compared to amaranth proteins, which reached 84.68% in Caco-2 and 81.06% in HepG2 cells. In conclusion, both amaranth and cañihua proteins, after simulated gastrointestinal digestion, showcased high digestibility and released peptides and amino acids with potent antioxidant properties, underscoring their potential health benefits.