Chickpea Seed Flours Improve the Nutritional and the Antioxidant Profiles of Traditional Shortbread Biscuits: Effects of In Vitro Gastrointestinal Digestion.

Functional gluten-free biscuits enriched with commercial and landrace non-commercial chickpea flours were designed and compared with a traditional shortbread biscuit. They were analyzed in sensory attributes, amino acid profile, and antioxidant properties. Subsequently, the biscuits were digested in vitro to evaluate protein hydrolysis, amino acid bioaccessibility, phenolic compounds release, and antioxidant markers. The presence of chickpea flours provided golden color and heightened biscuit hardness and fracturability (especially in non-commercial), increasing crispness and reducing brittleness. The protein hydrolysis was similar among samples (≈15%), except for one of the non-commercial (≈20%). Amino acids such as arginine, phenylalanine, leucine, tyrosine, and lysine exhibited the highest bioaccessibilities. Incorporating chickpea flour improved the antioxidant activity and polyphenol content in undigested samples and bioaccesible fractions, with higher levels of p-coumaric and ferulic acids after digestion, regardless of the chickpea seed. Non-commercial flours increased the presence of resveratrol and/or catechin in the bioaccessible fraction. Antioxidant action assessed in the Caco-2 cell line showed that the protective effect against reactive oxygen species (ROS) generation did not always correlate with the in vitro antioxidant capacity. Our data support that the inclusion of chickpea flours in the formulation of functional biscuits provides the consumer with products of added nutritional value with attractive organoleptic features.

The plasma membrane Na+/H+ antiporter SOS1 is essential for salt tolerance in tomato and affects the partitioning of Na+ between plant organs.

We have identified a plasma membrane Na(+)/H(+) antiporter gene from tomato (Solanum lycopersicum), SlSOS1, and used heterologous expression in yeast to confirm that SlSOS1 was the functional homolog of AtSOS1. Using post-transcriptional gene silencing, we evaluated the role played by SlSOS1 in long-distance Na(+) transport and salt tolerance of tomato. Tomato was used because of its anatomical structure, more complex than that of Arabidopsis, and its agricultural significance. Transgenic tomato plants with reduced expression of SlSOS1 exhibited reduced growth rate compared to wild-type (WT) plants in saline conditions. This sensitivity correlated with higher accumulation of Na(+) in leaves and roots, but lower contents in stems of silenced plants under salt stress. Differential distribution of Na(+) and lower net Na(+) flux were observed in the xylem sap in the suppressed plants. In addition, K(+) concentration was lower in roots of silenced plants than in WT. Our results demonstrate that SlSOS1 antiporter is not only essential in maintaining ion homeostasis under salinity, but also critical for the partitioning of Na(+) between plant organs. The ability of tomato plants to retain Na(+) in the stems, thus preventing Na(+) from reaching the photosynthetic tissues, is largely dependent on the function of SlSOS1.

Heterologously expressed protein phosphatase calcineurin downregulates plant plasma membrane H+-ATPase activity at the post-translational level.

To investigate the effects of calcineurin expression on cellular ion homeostasis in plants, we have obtained a transgenic cell culture of tomato, expressing constitutively activated yeast calcineurin. Transgenic cells exhibited reduced growth rates and proton extrusion activity in vivo. We show that reduction of plasma membrane H+-ATPase activity by expression of calcineurin is the basis for the observed phenotypes. Transgenic calli and cell suspensions displayed also increased salt tolerance and contained slightly higher Ca2+ and K+ levels. This demonstrates that calcineurin can modulate ion homeostasis in plants as it does in yeast by affecting the activity of primary ion transporters.