Abstract Seaweeds or marine macroalgae are sources of industrial important macro compounds. This work characterizes the chemical composition, morphology, cellular structure, morphometric parameters, protein distribution, density, and quantifies the chemical elements of three seaweed species. The morphological characterization performed by Digital Image Analysis (DIA) showed that the length/width ratio for UF (Ulva fasciata) (15.4/10.9 cm) was greater compared to SC (Sargassum cymosum) and GS (Grateloupia subpectinata) (8.9/7.6 cm and 87/5.3 cm). Using Schiff's and Coomassie blue reagents, identified carbohydrates and proteins in cells and protein bodies (PB). Cell morphology showed larger cells in the SC cortex (457.8 µm2) and smaller cells in the SC meristoderm (80.5 µm2). PB density (PB/area) and distribution (area occupied by the cell, %) were higher in the cortex of GS (10468 PB/mm2, 20%) and lower in the meristoderm of SC (917 PB/mm2, 7%). Chemical analysis showed as major compounds: carbohydrates (12-46%), ashes (13-42%), and proteins (6-17%). Meanwhile, the concentration of metals was below the toxicity level. These results contribute to the knowledge of the structure-function relationship of seaweeds metabolites which could be a source of compounds of interest for the industrial sector.

Inga paterno is a tree legume present in various states of Mexico whose sheath is consumed in someplaces as a fruit due seed coat is sweet (Aryl). Seeds are not commonly consumed and there are few studies about its composition. The physical characteristics, nutritional and non-nutritional composition of Inga paterno seeds from México State and Puebla were analyzed. The seeds showed a significant proportion of protein and lipid. The oil from the seeds showed higher proportion of palmitic acid. Non-nutritional compounds such as phenolics, tannins, phytates, saponins and trypsin inhibitors were quantified. The seeds of the two sources of origin showed no statistically significant difference in their physical, chemical and non-nutritional characteristics; however, unlike other legumes, they exhibit high saponins content and high inhibitory trypsin activity.

Inga paterno es una leguminosa arbórea, que crece varios estados de México. La vaina se consume como fruto, debido a la cubierta dulce (Arilo) de la semilla. Ésta última, no es comúnmente consumida. Las características físicas, composición nutricional y el contenido de compuestos no nutricionales presentes en las semillas de Inga paterno provenientes de los Estados de México y Puebla fueron analizados, mostrando que las semillas son de 1.6 y 1.9 cm largo y 0.9 y 1.08 cm de ancho. Los componentes químicos principales son: proteína (20.42 y 21.59 g/100 g), carbohidratos (28.99 y 36.15 g/100 g), lípidos (9.62 y 8.55 g/100 g) para las procedentes de Ozumba y Tochimilco, respectivamente. Los aceites de las semillas de Inga paterno presentaron una proporción importante de ácido palmítico, así como ácidos 7-octadecanoico, oleico, linoleico y alfa linolénico. Se cuantificaron los compuestos no nutricionales como fenólicos (0.55 y 0.54 mg eq. de ácido gálico/g), taninos (1.46 y 1.51 mg eq. de (+)-catequina/g), fitatos (2.66 y 2.04 mg de ácido fítico/g), saponinas (32.35 y 33.38 mg de diosgenina/g) e inhibidores de tripsina (311.97 y 351.21 mg de tripsina pura inhibida/g de muestra). Ambas semillas analizadas no presentaron diferencia estadísticamente significativa en sus características físicas, químicas y no nutricionales; sin embargo, éstas presentan una elevada actividad inhibitoria de tripsina comparada con otras leguminosas.

Phaseolus lunatus protein concentrates and the proteases Alcalase(R) and Pepsin-Pancreatin were used for the production of protein hydrolysates that inhibit angiotensin-I converting enzyme (ACE). Protein concentrate obtained from germinated and ungerminated seeds flour was hydrolyzed with Alcalase(R) at enzyme/substrate ratio (E/S) 1/10 and during 0.5 and 2.0 h, respectively. On the other hand, protein concentrate obtained from ungerminated (E/S: 1/10) and germinated (E/S: 1/50) seeds flour was sequentially hydrolyzed with Pepsin-Pancreatin during 1.0 and 3.0 h, respectively. Peptide fractions with ACE inhibitory activity in a range of 0.9 to 3.8 µg/mL were obtained by G-50 gel filtration chromatography and high- performance liquid chromatography C18 reverse phase chromatography. The observed amino acid composition suggests a substantial contribution of hydrophobic residues to the peptides’ inhibitory potency, which potentially acts via blocking of angiotensin II production. These results show that P. lunatus seed proteins are a potential source of ACE inhibitory peptides when hydrolyzed with Alcalase(R) and Pepsin-Pancreatin.

Significant initiatives exist within the global food market to search for new, alternative protein sources with better technological, functional, and nutritional properties. Lima bean (Phaseolus lunatus L.) protein isolate was hydrolyzed using a sequential pepsin-pancreatin enzymatic system. Hydrolysis was performed to produce limited (LH) and extensive hydrolysate (EH), each with different degrees of hydrolysis (DH). The effects of hydrolysis were evaluated in vitro in both hydrolysates based on structural, functional and bioactive properties. Structural properties analyzed by electrophoretic profile indicated that LH showed residual structures very similar to protein isolate (PI), although composed of mixtures of polypeptides that increased hydrophobic surface and denaturation temperature. Functionality of LH was associated with amino acid composition and hydrophobic/hydrophilic balance, which increased solubility at values close to the isoelectric point. Foaming and emulsifying activity index values were also higher than those of PI. EH showed a structure composed of mixtures of polypeptides and peptides of low molecular weight, whose intrinsic hydrophobicity and amino acid profile values were associated with antioxidant capacity, as well as inhibiting angiotensin-converting enzyme. The results obtained indicated the potential of Phaseolus lunatus hydrolysates to be incorporated into foods to improve techno-functional properties and impart bioactive properties.