Inhibition of Protein and Lipid Oxidation in Ready-to-Eat Chicken Patties by a Spondias mombin L. Bagasse Phenolic-Rich Extract

This study evaluated the impact of yellow mombin (Spondias mombin L.) bagasse extract (YMBE) on the color degradation, protein and lipid oxidation in ready-to-eat chicken patties during 15 days of refrigerated storage. Two formulations of chicken patties were developed: chicken patties control - PCON (without the antioxidant extract) and chicken patties with yellow mombin extract - PYME (with the antioxidant extract). The extract was effective in maintaining red color and inhibiting myoglobin degradation in the evaluated samples. The generation of lipid oxidation compounds during storage of the treated samples was delayed by 92.37% for peroxide index, 89.89% for conjugated dienes, 74.29% for tiobarbituric acid reactive substances (TBARs) and 92.55% for ρ-anisidine compared to the control samples. Moreover, the addition of YMBE inhibited the formation of carbonyl compounds during cold storage compared to the control samples. Extracts obtained from the yellow mombin bagasse act as a good natural antioxidant for ready-to-eat chicken patties inhibiting protein and lipid oxidative damage during cold storage, being a potential preservative to replace synthetic antioxidants in meat products.

Potassium Channel Activation Is Involved in the Cardiovascular Effects Induced by Freeze Dried Syzygium jambolanum (Lam.) DC Fruit Juice

This work aimed to explore the cardiovascular effects induced by freeze-dried juice from Syzygium jambolanum (Lam.) DC fruits (JSJ). JSJ presented high polyphenol content and steroids. HPLC analysis revealed that 2,5-dihydroxybenzoic and caffeic acid were present in higher amounts in the JSJ extract. In rat, JSJ induces hypotension and vasodilatation in mesenteric arteries, with or without vascular endothelium. JSJ-mediated vasodilation response against contractions induced with KCl (60 mM) depolarizing solution was significantly lower than the responses induced by JSJ when evaluated against phenylephrine-induced contractions. To investigate the involvement of potassium channels we used Tyrode's solution with KCl (20 mM) or tetraethylammonium (1.0, 3.0, or 5.0 mM). In these conditions JSJ-induced effects were significantly attenuated. To investigate the potassium channel subtypes involved in the response, we used 4-aminopyridine, glibenclamide, BaCl2, and iberiotoxin. In the presence (simultaneous) of different potassium channel blockers we observed a significant attenuation of JSJ-induced effect. Inhibition was also observed when using BaCl2, glibenclamide, or 4-aminopyridine, separately. However, incubation with iberiotoxin did not promote changes in either maximum effect, or potency. We also evidenced a discrete participation of CaV channels in the JSJ-induced vasorelaxant effect. In addition, patch-clamp studies demonstrated that JSJ could activate potassium channels. In conclusion, JSJ promotes hypotension and vasorelaxation in rats, involving, at least, the activation of potassium channels.

Antioxidant and vasorelaxant activities induced by northeastern Brazilian fermented grape skins

Background

In northeastern Brazil, grape pomace has become a potential alternative byproduct because of the recover phenolic compounds from the vinification process. Comparative analyses were performed between lyophilized extract of grape skins from pomace, described as fermented (FGS), and fresh, unfermented (UGS) grape skins to show the relevant brand’s composition upon the first maceration in winemaking.

Methods

The use of in vitro testing such as Folin-Ciocalteu’s, DPPH free radical scavenger and HPLC methods were performed to evidence antioxidant effect and phenolic compounds. Additionally, vascular reactivity studies were performed in third-order branches of rat superior mesenteric arteries, which were obtained and placed in organ baths containing Krebs-Henseleit solution, maintained at 37 °C, gassed with a mixture of 95% O₂ and 5% CO₂, and maintained at pH 7.4. The in situ formation of reactive oxygen species (ROS) was evaluated in small mesenteric rings using oxidative fluorescent dihydroethidium dye.

Results

We found higher phenolic content and antioxidant activity in FGS when compared to UGS. HPLC analyses identified a significant number of phenolic compounds with antioxidant potential in both samples. The vasorelaxant effect induced by FGS was more potent than that induced by UGS, and the activity was attenuated after removal of vascular endothelium or by blockade of endothelium-derived relaxing factors, such as NO and EDHF.

Conclusions

The FGS extract may be a great source of natural polyphenol products with potent antioxidant effects and endothelium-dependent vasodilatory actions involving NO and EDHF pathways.