Common bean protein hydrolysate modulates lipid metabolism and prevents endothelial dysfunction in BALB/c mice fed an atherogenic diet.

BACKGROUND AND AIMS: Common beans (Phaseolus vulgaris L.) protein hydrolysate is a source of bioactive peptides with known health benefits. The aim of this study was to evaluate the effect of common bean protein hydrolysate on lipid metabolism and endothelial function in male adult BALB/c mice fed an atherogenic diet for nine weeks. METHODS AND RESULTS: Male adult mice were divided into three experimental groups (n = 12) and fed with normal control diet; atherogenic diet and atherogenic diet added with bean protein hydrolysate (700 mg/kg/day) for nine weeks. Food intake, weight gain, lipid profile, Atherogenic Index of Plasma, inflammation biomarkers and endothelial function were evaluated. APH group presented reduced feed intake, weight gain, lipid profile, tumor necrosis factor-α, angiotensin II (94% and 79%, respectively) and increased endothelial nitric oxide synthase (62%). CONCLUSIONS: Protein hydrolysate showed hypocholesterolemic activity preventing inflammation and dysfunction of vascular endothelium, in addition to decreasing oxidative stress, indicating an adjuvant effect on reducing atherogenic risk.

Production, Quality, and Acceptance of Tempeh and White Bean Tempeh Burgers.

The food industry has been challenged to develop new healthy food products. Tempeh, originating in Indonesia and produced by fungal fermentation, would be an alternative healthy food for the Brazilian population. This study was designed to produce white bean (cv BRS Ártico) tempeh burger, to determine and compare its nutritional and sensory properties with conventional soybean-based tempeh burger. The production and the analyses of proximal composition and microbiological contamination were determined in the tempeh, following reference methods. For the sensory analysis, a nine-point hedonic scale test was performed with 82 untrained evaluators, and at the end, a question of purchase intent was answered. The results indicated significant differences in the nutritional value of the tempehs, which is justified by the difference in the composition of the raw materials used. The samples did not present a risk of microbiological contamination for consumption. The white bean tempeh burgers showed similar appearance and crispy consistency, but received lower scores for flavor, compared to the soybean burgers, probably due to their residual beany flavor. The beany flavor could be minimized by increasing the cooking time of the beans. White bean tempeh can be a good alternative for healthy eating, and its manufacture could promote the production of new products made from beans, giving a new focus to the Brazilians' traditional food. It is still necessary to improve the techniques of production and test new ingredients for the preparation of tempeh burgers to obtain higher acceptability.

Rheological and biochemical properties of Solanum lycocarpum starch.

This study was conducted to evaluate the rheological and physicochemical properties of Solanum lycocarpum starch. The thermogravimetric analysis of S. lycocarpum starch showed a typical three-step weight loss pattern. Microscopy revealed significant changes in the granule morphology after hydrothermal treatment. Samples hydrothermally treated at 50°C for 10 min lost 52% of their crystallinity, which was recovered after storage for 7 days at 4°C. However, samples hydrothermally treated at 65°C were totally amorphous. This treatment was sufficient to completely disrupt the starch granule, as evidenced by the absence of an endothermic peak in the DSC thermogram. The RVA of S. lycocarpum starch revealed 4440.7cP peak viscosity, 2660.5cP breakdown viscosity, 2414.1cP final viscosity, 834.3cP setback viscosity, and a pasting temperature of 49.6°C. The low content of resistant starch (10.25%) and high content of digestible starch (89.78%) in S. lycocarpum suggest that this starch may be a good source for the production of hydrolysates, such as glucose syrup and its derivatives.

Amylolytic activity in fruits: comparison of different substrates and methods using banana as model.

Several methodologies have been developed for cereal amylolytic activity estimation, but there is lack of information about the application of these methods for fruits. Mature green banana fruit can achieve 20% of starch content which is degraded during the ripening period in a complex process involving alpha- and beta-amylases and alpha-1,4 and alpha-1,6-glucosidases, besides phosphorylases that can compete for the same substrates. Methods used to determine total hydrolytic activity and individual activity of enzymes involved in starch breakdown were compared for banana extracts in several ripening stages. Total hydrolytic activity was measured by DNS and iodometric methods. Endoamylolytic activity on amylose-azure substrate was also evaluated. BPNPG7 and PNPG5 chromogenic substrates were used for alpha- and beta-amylase activities, respectively. The results showed that methods that depend on the use of thermal treatment or on inhibitors to inactivate one of the enzymes were not adequate. The use of p-nitrophenol derivatives seemed to be the most specific, reproducible, and easiest method employed for single alpha- and beta-amylases activities determination in complex tissues. The DNS and iodometric methods can be used only for initial screenings of total hydrolytic activity, because the nonspecific substrate used in these procedures allows the action of more than one enzyme simultaneously.