Blackcurrant pomace, rich in fiber and polyphenols, can be used as added-value ingredient for food formulation. However, the bounding of polyphenols to pomace and the interactions that take place with food nutrients modify polyphenol bioaccessibility. This work studied the interactions between polyphenols and the main macronutrients in foods, and the changes that occurred during in vitro digestion, using model systems. Model systems were formulated with (i) water, (ii) wheat starch, (iii) olive oil, (iv) whey protein, and (v) a model combining all the ingredients. Polyphenols were added from two sources: as pomace and as a polyphenolic pomace extract. Interactions between polyphenols and macronutrients were studied using light microscopy; total phenolic content (TPC) and antioxidant capacity (AC) were determined before and after the in vitro digestion process. Lastly, the bioaccessibility of the samples was calculated. Polyphenols incorporated into the model systems as pomace increased their bioaccessibility if compared to polyphenols added as extract. For single-nutrient model systems formulated with pomace, the bioaccessibility was higher than when the system contained all the nutrients. Of all the components studied, the greatest effect on bioaccessibility was observed for proteins.

This study assessed the effect of substituting 30% of fat by soluble, insoluble fiber, or a mix of both fibers in sponge cake quality, structure, acceptability, and starch digestibility. The apparent viscosity of the different formulations was measured and micro-baking was simulated. Texture profile tests were carried out and the crumb structure was examined. In vitro digestion was performed to study the digestibility of starch and a sensory test was carried out to know consumer acceptance. The soluble fiber (maltodextrin) affected the structure and quality of the cakes less than the insoluble fiber (potato fiber) and the use of soluble fiber in the formulation resulted in lower glucose release under in vitro conditions. Moreover, the consumer did not find differences among the control cake and the cakes prepared with soluble fiber. Considering the results as a whole, soluble fiber may be used for partial replacement of fat in sponge cake formulations and may constitute an appropriate strategy for obtaining healthy sponge cakes.

High hydrostatic pressure is a non-thermal treatment of great interest because of its importance for producing food with additional or enhanced benefits above their nutritional value. In the present study, the effect of high hydrostatic pressure processing parameters (200–500 MPa; 1–10 min) is investigated through response surface methodology (RSM) to optimize the treatment conditions, maximizing the phenol content and antioxidant capacity while minimizing microbiological survival, in milkshakes prepared with chokeberry pomace (2.5–10%). The measurement of fluorescence intensity of the samples was used as an indicator of total phenolic content and antioxidant capacity. The results showed that the intensity of the treatments had different effects on the milkshakes. The RSM described that the greatest retention of phenolic compounds and antioxidant capacity with minimum microbiological survival were found at 500 MPa for 10 min and 10% (w/v) chokeberry pomace. Therefore, this study offers the opportunity to develop microbiologically safe novel dairy products of high nutritional quality.

There is increasing interest in foods that support both physical and psychological health. Red and black fruits are notable for their high phenolic content and associated biological activities. However, their natural sugar content may raise concerns regarding glycemic impact. Recent breeding programs have developed new seedless table grape varieties with black skin and red pulp, aiming to enhance phenolic content and reduce glycemic response. This study evaluates these novel grape varieties using in vitro models of intestinal absorption and hepatic insulin resistance. Specifically, we assessed phenolic content, antioxidant capacity, glucose transport across intestinal cells, and the modulation of biomarkers related to insulin resistance. The results showed that the new grape varieties (hybrids) showed total phenolic contents of 52.4–187.3 mg GAE/100 g FW and antioxidant capacities ranging between 195.3 and 762.7 mg Trolox equivalents/100 g FW, both higher than those of commercial table grapes. These new varieties also showed a lower percentage of intestinal glucose transport than commercial grapes and pineapple in caco-2 cells, suggesting an improved regulation of glucose uptake. Theoretical transport values confirmed a reduced glycemic impact for most hybrids, while absorbed fractions of RF03, RF05, and RF06 also restored hepatic glycogen levels under insulin-resistant conditions, indicating enhanced glucose metabolism. Overall, our in vitro findings suggest that these new grape varieties may help modulate postprandial glucose levels, supporting their potential as a healthier fruit option.

Revista oficial de la Sociedad Española de Nutrición Parenteral y de la Sociedad Española de Nutrición. Está dedicada al estudio y divulgación de temas relacionados con la nutrición.