Leticia Olivera-Castillo

Cowpea (Vigna unguiculata) protein concentrate as replacement for fish meal in diets for tilapia (Oreochromis niloticus) fry

Abstract This study provides information on the dietary efficiency of protein concentrate from cowpea seed, as an ingredient for practical diets of tilapia fry. Five experimental diets were prepared in which animal protein (fish meal) was replaced by increasing amounts of plant protein, and fed to tilapia during a nine-week period to assess the effect on growth, survival and feed efficiency. The highest growth rate and feed utilization was observed with 20–30% replacement of fish meal with cowpea protein concentrate, while the protein efficiency was best at 40% inclusion level. No mortalities related to the dietary plant protein were recorded. It is concluded that cowpea seed protein concentrate is a potential ingredient for use in feeding tilapia fry, and its use is recommended at the inclusion levels described in this paper.

Correction: Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats.

Fig 1 is incorrect in both the original article and the correction published on March 6, 2015. The CNC data points and CC data points are erroneously switched. The authors have provided a corrected version here. Fig 1 Weight gain in rats during dietary supplementation period.

Protein hydrolysate fractions from sea cucumber (Isostichopus badionotus) inhibit angiotensin-converting enzyme

ABSTRACT Angiotensin-converting enzyme (ACE) inhibitory capacity was evaluated in hydrolysates from sea cucumber Isostichopus badionotus. The pepsin-pancreatin and Alcalase®-Flavorzyme® sequential systems were used. Hydrolysates were characterized in terms of degree of hydrolysis (DH), electrophoretic profile, and inhibitory activity. The Alcalase®-Flavorzyme® system produced hydrolysates with the highest DH, with that produced at 90 min exhibiting the highest ACE inhibitory action (86%). This hydrolysate was chosen for purification by ultrafiltration with five molecular weight cut-offs (< 1, 1–3, 3–5, 5–10, and > 10). The > 10-kDa fraction exhibited the highest ACE inhibitory action (80.7%) and was fractionated by gel fractionation chromatography. Of the 11 resulting fractions, IX had the highest ACE inhibitory action (73.4%) and lowest IC50 value (2-μg prot/mL). Hydrolysis of sea cucumber I. badionotus with the Alcalase®-Flavorzyme® system produced hydrolysates with ACE inhibitory action. These contained a peptide with an IC50 value comparable to those of synthetic ACE inhibitors.