Aprendizajes y trayectorias del sector agroalimentario mexicano durante el TLCAN

Ante la firma del Tratado México, Estados Unidos y Canadá (T-MEC), es importante hacer un balance de los efectos que dejó tras de sí el Tratado de Libre Comercio de América del Norte (TLCAN) en el sector agropecuario. Por ello, connotados especialistas analizan factores socioeconómicos del sistema agroalimentario mexicano en el contexto de las relaciones comerciales con Estados Unidos y Canadá. Los 10 estudios que contiene el libro Aprendizajes y trayectorias del sector agroalimentario mexicano durante el TLCAN son de gran valía para la obtención de conocimiento especializado para comprender críticamente las lógicas, trayectorias, evolución y comportamientos de las cadenas productivas a la luz de la firma de los tratados comerciales de América del Norte, así como sus efectos en el campo mexicano, territorios rurales y consumidoresFinanciación del Instituto Interamericano de Cooperación para la Agricultura en colaboración con autore

Transformación y mejora del valor nutritivo de la harina de guisante mediante la adición de enzima fitasa

Tesis Univ. Granada. Departamento de Fisiología. Leída el 20 de marzo de 200

Effect of phytic acid degradation by soaking and exogenous phytase on the bioavailability of magnesium and zinc from Pisum sativum, L.

The effect of dephytinization of Pisum sativum, L. flour on the bioavailability of Mg and Zn was evaluated in growing rats. Processing of legume flours under optimal conditions for phytase activity (pH 5.5, 37 °C, 60 min) and subsequent removal of the soaking solution led to a 42 and 61% reduction in the content of Mg and Zn, respectively. Treatment with phytase led to an additional reduction in the concentration of the above-mentioned seed flour components, compared to the raw pea flour (69% and 74% for Mg and Zn, respectively). The considerable reduction in the content of inositol phosphates with high degree of phosphorylation attained under both processing conditions did not affect the digestive utilization of Mg, whereas the metabolic utilization of this mineral increased significantly. The digestive and metabolic utilization of Zn increased significantly in response to both processes assayed, reaching the highest values in the experimental group that was fed the phytase-treated pea flour diet. The amount of Mg retained by the experimental animals was reflected in the content of this mineral in the different tissues studied (femur, sternum, kidney, and heart), whereas no correlation was found in the case of ZnWe thank Mrs. Rosa Jiménez for skilful technical assistance. This research was funded by the Project AGL2002-02905 ALI of the Spanish CICYT.Peer reviewe

Nutritional assessment of raw and germinated pea (Pisum sativum L.) protein and carbohydrate by in vitro and in vivo techniques

[Objective] We assessed the effect of germinating Pisum sativum L. variant Arvense cv. Esla for 3 and 6 d in darkness on the chemical composition and nutritive utilization of protein and carbohydrates. [Methods] Nutritional assessment of protein and carbohydrates was based on chemical analysis of raw and germinated pea flours and in vitro and in vivo rat balance methodologies. [Results] Germination caused a notable decrease in α-galactoside content and significant increases in sucrose, glucose, and fructose. The ratio of available starch to total starch increased as a consequence of processing. The content of vitamin B2 increased significantly, whereas no significant change was observed in vitamin B1 content in germinated peas. Protein digestibility assessed with an in vivo technique (apparent digestibility coefficient) or as the percentage of dialyzable nitrogen increased significantly as a result of germination in contrast to what was observed with the in vitro pH-drop methodology. Daily food intake, nitrogen absorption and balance, percentage of retained versus absorbed nitrogen, protein efficiency ratio, and the index of available carbohydrates were significantly improved by germination for 3 d and significantly decreased by germination for 6 d. [Conclusions] Germination of pea seeds for 3 d significantly improves palatability of these seeds and the nutritive utilization of protein and carbohydrates.Peer Reviewe

Nutritional evaluation of pea (Pisum sativum L.) Protein diets after mild hydrothermal treatment and with and without added phytase

The effect of mild hydrothermal treatment and the addition of phytase under optimal conditions (pH 5.5, 37 °C) on the nutritive utilization of the protein of pea (Pisum sativum L,) flour was studied in growing rats by examining the chemical and biological balance. Mild hydrothermal treatment produced reductions of 83, 78, and 72%, respectively, in the levels of α-galactosides, phytic acid, and trypsin inhibitors and also produced a significant increase in the digestive utilization of protein. The additional fall in the levels of phytic acid caused by the addition of phytase did not lead to a subsequent improvement in the digestive utilization of protein. The mild hydrothermal treatment of pea flour produced a significant increase in the metabolic utilization of protein and carbohydrates, which was reflected in the protein efficiency ratio and food transformation growth indices. These effects were not observed in the phytase-supplemented pea diet.Peer Reviewe

Effect of treatment with α-galactosidase, tannase or a cell-wall-degrading enzyme complex on the nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour

The effect of treatment with α-galactosidase, tannase or a cell-wall-degrading enzyme complex under optimal conditions of pH, temperature and length of incubation time on the chemical composition and nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour was studied. Soaking of pea flours in combination with enzyme treatment led to reductions of 77–90% in the levels of α-galactosides, and of 60–80% in the levels of trypsin inhibitor activity, increasing the content of total available sugars, which was highest in the pea flour treated with the cell-wall-degrading enzyme complex. All the treatments assayed caused a significant improvement in daily food intake, whereas the nutritive utilisation of protein was not increased in any of the pea products tested when compared to the raw pea flour. However, all the soaking and enzymatic treatments led to a significant improvement in daily weight gain associated with a higher dietary intake of food and total available sugars.Project AGL2002-02905 ALI from the Spanish CICYTPeer reviewe