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1.
J Dairy Sci ; 99(9): 6927-6936, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27344382

RESUMEN

A disregarded nutritional feature of cheeses is their high acid-forming potential when ingested, which is associated with deleterious effects on consumers' health. This work aimed to characterize the acid-forming potential of a blue-veined cheese during manufacturing to identify the main steps of the process involved in this phenomenon. Sampling was performed on 3 batches at 10 steps of the cheese-making process: reception of raw milk, pasteurization, maturation of milk, coagulation, stirring, draining of the curds, and 4 ripening stages: 21, 28, 42, and 56d. The acid-forming potential of each sample was evaluated by (1) the calculation of the potential renal acid load (PRAL) index (considering protein, Cl, P, Na, K, Mg, and Ca contents), and (2) its organic anion content (lactate and citrate), considered as alkalinizing elements. Draining and salting were identified as the main steps responsible for generation of the acid-forming potential of cheese. The draining process induced an increase in the PRAL index from 1.2mEq/100g in milk to 10.4mEq/100g in drained curds due to the increase in dry matter and the loss of alkaline minerals into the whey. The increase in PRAL value (20.3mEq/100g at d 56) following salting resulted from an imbalance between the strong acidogenic elements (Cl, P, and proteins) and the main alkalinizing ones (Na and Ca). Particularly, Cl had a major effect on the PRAL value. Regarding organic anions, draining induced a loss of 93% of the citrate content in initial milk. The lactate content increased as fermentation occurred (1,297.9mg/100g in drained curds), and then decreased during ripening (519.3mg/100g at d 56). This lactate level probably helps moderate the acidifying potential of end products. Technological strategies aimed at limiting the acid-forming potential of cheeses are proposed and deserve further research to evaluate their nutritional relevance.


Asunto(s)
Queso/análisis , Manipulación de Alimentos/métodos , Sales (Química)/análisis , Animales , Calcio/análisis , Cloro/análisis , Ácido Cítrico/análisis , Análisis de los Alimentos , Concentración de Iones de Hidrógeno , Ácido Láctico/análisis , Magnesio/análisis , Leche/química , Proteínas de la Leche/análisis , Pasteurización , Fósforo/análisis , Potasio/análisis , Sodio/análisis
2.
Pediatr Res ; 66(5): 513-8, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19668107

RESUMEN

Peak bone mass is a major determinant of osteoporosis pathogenesis during aging. Respective influences of energy and protein supplies on skeletal growth remains unclear. We investigated the effect of a 5-mo dietary restriction on bone status in young rats randomized into six groups (n = 10 per group). Control animals were fed a diet containing a normal (13%) (C-NP) or a high-protein content (26%) (C-HP). The other groups received a 40% protein energy-restricted diet (PER-NP and PER-HP) or a 40% energy-restricted diet (ER-NP and ER-HP). High-protein intake did not modulate bone acquisition, although a metabolic acidosis was induced and calcium retention impaired. PER and ER diets were associated with a decrease in femoral bone mineral density. The compensation for protein intake in energy-restricted conditions induced a bone sparing effect. Plasma osteocalcin (OC) and urinary deoxypyridinoline (DPD) assays revealed a decreased OC/DPD ratio in restricted rats compared with C animals, which was far more reduced in PER than in ER groups. Circulating IGF-1 levels were lowered by dietary restrictions. In conclusion, both energy and protein deficiencies may contribute to impairment in peak bone mass acquisition, which may affect skeleton strength and potentially render individuals more susceptible to osteoporosis.


Asunto(s)
Huesos/patología , Suplementos Dietéticos , Aminoácidos/orina , Alimentación Animal , Animales , Fenómenos Biomecánicos , Densidad Ósea , Fémur/anatomía & histología , Factor I del Crecimiento Similar a la Insulina/metabolismo , Iones , Masculino , Osteocalcina/sangre , Osteoporosis/patología , Ratas , Ratas Wistar
3.
J Agric Food Chem ; 56(20): 9417-22, 2008 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-18800805

RESUMEN

This study was conducted to determine whether the daily consumption for 84 days of tyrosol and hydroxytyrosol, the main olive oil phenolic compounds, and olive oil mill wastewater (OMWW), a byproduct of olive oil production, rich in micronutrients, may improve bone loss in ovariectomized rats (an experimental model of postmenopausal osteoporosis) and in ovariectomized rats with granulomatosis inflammation (a model set up for senile osteoporosis). As expected, an induced chronic inflammation provoked further bone loss at total, metaphyseal, and diaphyseal sites in ovariectomized rats. Tyrosol and hydroxytyrosol prevented this osteopenia by increasing bone formation ( p < 0.05), probably because of their antioxidant properties. The two doses of OMWW extracts had the same protective effect on bone ( p < 0.05), whereas OMWW did not reverse established osteopenia. In conclusion, polyphenol consumption seems to be an interesting way to prevent bone loss.


Asunto(s)
Conservadores de la Densidad Ósea/farmacología , Inflamación/tratamiento farmacológico , Osteoporosis/tratamiento farmacológico , Ovariectomía/efectos adversos , Alcohol Feniletílico/análogos & derivados , Aceites de Plantas/farmacología , Animales , Densidad Ósea/efectos de los fármacos , Modelos Animales de Enfermedad , Femenino , Flavonoides/farmacología , Humanos , Aceite de Oliva , Osteoporosis/fisiopatología , Fenoles/farmacología , Alcohol Feniletílico/farmacología , Aceites de Plantas/química , Polifenoles , Distribución Aleatoria , Ratas , Ratas Wistar
4.
J Nutr ; 138(4): 718-24, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18356326

RESUMEN

High dietary protein intake generates endogenous acid production, which may adversely affect bone health. Alkaline potassium citrate (Kcit)(2) may contribute to the neutralization of the protein-induced metabolic acidosis. We investigated the impact of 2 levels of protein intake and Kcit supplementation on acid-base metabolism and bone status in rats. Two-month-old Wistar male rats were randomly assigned to 4 groups (n = 30 per group). Two groups received a normal-protein content (13%) (NP) or a high-protein (HP) content diet (26%) for 19 mo. The 2 other groups received identical diets supplemented with Kcit (3.60%) (NPKcit and HPKcit). Rats were pair-fed based on the ad libitum intake of the HP group. At 9, 16, and 21 mo of age, 10 rats of each group were killed. The HP diet induced a metabolic acidosis characterized by hypercalciuria, hypermagnesuria, and hypocitraturia at all ages. Kcit supplementation neutralized this effect, as evidenced by decreased urinary calcium and magnesium excretion by the HPKcit rats. Femoral bone mineral density, biomechanical properties, bone metabolism biomarkers (osteocalcin and deoxypyridinoline), and plasma insulin-like growth factor 1 levels were not affected by the different diets. Nevertheless, at 21 mo of age, calcium retention was reduced in the HP group. This study suggests that lifelong excess of dietary protein results in low-grade metabolic acidosis without affecting the skeleton, which may be protected by an adequate calcium supply.


Asunto(s)
Equilibrio Ácido-Base/efectos de los fármacos , Densidad Ósea/efectos de los fármacos , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/farmacología , Citrato de Potasio/administración & dosificación , Citrato de Potasio/farmacología , Animales , Aniones/orina , Biomarcadores , Fenómenos Biomecánicos , Peso Corporal , Calcio/metabolismo , Cationes/orina , Suplementos Dietéticos , Esquema de Medicación , Quimioterapia Combinada , Masculino , Ratas , Ratas Wistar
5.
Clin Nutr ; 25(5): 859-68, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16740345

RESUMEN

BACKGROUND & AIMS: This study was carried out to assess the dose-dependent bone-sparing effect of oleuropein, an olive oil phenolic compound with anti-inflammatory and anti-oxidative properties, on bone loss induced by talc granulomatosis in oestrogen-deficient rat. METHODS: Among 98 rats, 20 were sham-operated (SH) while the others (78) were ovariectomised (OVX). The SH and 26 OVX rats (controls) were given a standard diet for 100 days. The 52 remaining OVX rats were allocated to 4 groups that received oleuropein at 2.5, 5, 10 or 15 mg/kg body weight per day for 100 days. Three weeks before necropsy, an inflammation was induced by subcutaneous injections of talc in half of the SH and OVX rats and in all oleuropein-treated animals. RESULTS: Castration was associated with a decreased bone mineral density (BMD). In OVX rats, inflammation, characterised by an increase of the spleen weight and plasma fibrinogen levels, exacerbated this bone loss, as shown by values of BMD of the total femur metaphyseal and diaphyseal subregions. The 4 doses of oleuropein reduced bone loss and improved inflammatory biomarkers excepted for 5mg/kg BW. CONCLUSIONS: Every dose of oleuropein elicited protective effects on bone mass in this model of ovariectomy associated with inflammation, probably by modulating inflammatory parameters.


Asunto(s)
Conservadores de la Densidad Ósea/farmacología , Osteoporosis/tratamiento farmacológico , Ovariectomía , Piranos/farmacología , Animales , Antiinfecciosos/farmacología , Antiinfecciosos/uso terapéutico , Biomarcadores/sangre , Densidad Ósea/fisiología , Conservadores de la Densidad Ósea/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Fibrinógeno/metabolismo , Inflamación/complicaciones , Glucósidos Iridoides , Iridoides , Aceite de Oliva , Tamaño de los Órganos , Ovariectomía/efectos adversos , Aceites de Plantas , Piranos/uso terapéutico , Distribución Aleatoria , Ratas , Ratas Wistar , Bazo/patología
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