Evaluation of in vitro whey protein digestibility in a protein-catechins model system mimicking milk chocolate: Interaction with flavonoids does not hinder protein bioaccessibility

Flavonoids are largely present in plant food such as cocoa and derived products. These compounds can interact with proteins inherently contained in the food matrix and/or the proteolytic enzymes involved in gastrointestinal digestion. The flavonoid/protein interaction might hamper protein bioaccessibility and digestibility, affecting the nutritional quality. However, information on the digestion fate of proteins in food matrices containing both proteins and flavonoids is limited. The aim of this work was to evaluate the interaction between proteins and flavonoids and verify the potential effects of this interaction on protein digestibility. Taking milk chocolate as model, first a simple whey proteins/catechins mixed system was evaluated, and then the effects on digestibility were also verified in a real sample of commercial milk chocolate. The effects of the catechins/whey proteins interaction in the model system were evaluated by optical and chiro-optical spectroscopy, outlining a slight protein structure modification upon interaction with catechins. The digestibility of the protein fraction both in the model system, with and without catechins, and also in milk chocolate, was then determined by the application of INFOGEST in vitro digestion method: the bioaccessibility was evaluated in terms of protein hydrolysis and protein solubilisation, and major peptides generated by the digestion were also determined by LC/HR-MS. Despite the slight interaction with proteins, flavonoids were found to not hinder nor modify protein solubilization, protein hydrolysis and peptide profile by digestive enzymes. Also protein digestibility in milk chocolate, evaluated by SDS-PAGE, was found to be complete. The present data clearly indicate that the interaction of the proteins with the flavonoids present in the cocoa matrix does not to affect protein bioaccessibility during digestion.

Structural and chemical changes induced by temperature and pH hinder the digestibility of whey proteins

In the food and feed industry, protein extraction is commonly performed under acid or basic conditions, combined with heat, in order to increase the extraction yield. Under severe processing conditions, proteins may undergo molecular modifications. Here, the effects of heating (30, 60, 90 °C) at different pH values (2, 7, 9, 11, 13) were evaluated on commercial whey proteins, used as a simplified protein model. The main structure and chemical modifications concerning protein aggregation, hydrolysis, insolubilization, amino acid degradation and racemization were investigated in detail. Using in vitro static models, the degree of protein hydrolysis and the released peptides were determined after the digestive process. Accumulation of molecular modifications was mostly observed after basic pH and high temperatures treatments, together with a marked decrease and modification of the digestibility profile. Instead, protein digestibility increased in neutral and acidic conditions in a temperature-dependent manner, even if some modification in the structure occurs.

Beneficial effects of a T. monococcum wheat cultivar on diabetes incidence evaluated in non-obese diabetic mice and after in vitro simulated gastroduodenal digestion

Wheat consumption can represent one of the nutritional factors involved in the onset of diabetes. We specifically investigated the potential diabetogenic effects of Hammurabi, a T. monococcum wheat cultivar, in non-obese diabetic (NOD) mice and analysed the levels of resistant starch in pasta manufactured with Hammurabi after in vitro gastroduodenal digestion. NOD mice were fed with Hammurabi, bread wheat or rice flour to evaluate diabetes incidence and insulitis score. An enzymatic method was applied to compare the content of resistant starch in Hammurabi pasta and durum wheat pasta (control). In NOD mice, the Hammurabi-based diet significantly delayed diabetes onset (p = 0.0042) and reduced insulitis score compared to rice or wheat-based diet. Furthermore, the resistant starch value following in vitro digestion of Hammurabi pasta was significantly higher (4.08%) than that of durum wheat pasta (2.28%). Taken together, these results highlighted the potential positive effects of the Hammurabi-based diet on diabetes incidence.

Precocious puberty in two girls with Chiari I malformation: a contribution to a larger use of brain MRI in the diagnosis of central precocious puberty

Up to now Chiari malformation has been reported only in four subjects with precocious puberty, with a prevalence among boys. This article describes the case of two female children affected by progressive precocious puberty detected through brain magnetic resonance imaging (MRI). Brain imaging, even without neurological signs, can identify patients at risk of developing subsequently severe neurological symptoms. Our observation supports the usefulness of brain MRI both in males and females, even when no symptoms are present, to identify and detect high risk cases. However, there is no consensus in Literature in performing MRI in all the patients of both sexes with central precocious puberty, due to its high costs.

The impact of coexistent diabetes on the prevalence of coronary heart disease

The increased risk of developing cardiovascular disease in diabetic population has been well documented, but the prevalent mechanism of this susceptibility is still only partly explained. We compared the impact of diabetes on ischemic heart disease in patients hospitalized in a public general hospital over a 10-year period. The prevalence of coronary heart disease (CHD) was consistently higher among diabetic population [namely, among non-insulin-dependent diabetes mellitus (NIDDM) patients] when compared with the nondiabetic population. The prevalence was similar in both genders, increasing with age, and was independent from body-mass index, history of smoking, metabolic control, or lipid pattern. Heart rate and blood pressure levels were significantly higher in NIDDM patients with CHD; similarly, there was a significant association between ischemic heart disease and atherosclerotic peripheral artery disease prevalence, and this trend was observed even in subjects with impaired glucose tolerance. These observations support the evidence that diabetes exerts a deleterious effect on general risk factors of atherosclerosis and increases susceptibility to cardiovascular disease by itself as an "independent" risk factor; on the other hand, the epidemiological evidence of an excessive occurrence of type II diabetes in individuals with pre-existing vascular disease suggests a genetically determined link between metabolic disturbances and cardiovascular disease.