Protein digestibility and ACE inhibitory activity of fermented flours in older adults and standard gastrointestinal simulation.

Consumption of essential amino acids responsible for muscle protein synthesis is important in preventing sarcopenia among older individuals. This population may experience gastrointestinal disorders that inhibit protein digestibility, making it crucial to address. Therefore, solid-state fermentation (SSF) using Pleurotus ostreatus and air drying has been suggested as a means of improving the protein digestibility of lentils and quinoa. SSF combined with air drying at 70 °C resulted in a slight increase in protein hydrolysis compared to unfermented samples. SSF was found to boost the proportion of small peptides to 35 %. Following digestion, SSF and drying yielded bioactive peptides of 1400 and 450 Da, with a range of 11 % to 28 %, respectively, and peptides < 190 Da making up 60 % of the total. SSF promoted valine, leucine, and isoleucine generation; however, hot air drying reduced free amino acids due to the amino acid-reducing sugar bonding but was never lower than the initial content of its unfermented counterpart. Furthermore, SSF and drying at 70 °C improved the release of hydrophobic amino acids (>70 mg/g dry basis) and negatively charged amino acids (>20 mg/g dry basis) in lentils during digestion. The SSF samples exhibited lower angiotensin converting enzyme (ACE) inhibitory activity, ≤35 %, compared to unfermented flours after digestion. However, the ACE inhibitory activity increased in SSF-dried samples, in part because of melanoidins generated during drying. Finally, lower values of protein digestibility and thus smaller peptides, amino acid profile, and ACE inhibitory activity of fermented flours were found in the older adult digestion model.

Flours from fermented lentil and quinoa grains as ingredients with new techno-functional properties.

The need to provide novel, nutritious plant-based products requires seeking high-value, sustainable protein sources, like quinoa and lentils, having an increased digestibility and lacking antinutrients. Fungal fermentation has evidenced enhanced nutritional value of flours obtained from these grains. However, research into techno-functional properties, essential to the new product development, is lacking. This study investigated the techno-functional properties of flours made from lentil and quinoa after fermenting them with Pleurotus ostreatus and subjecting them to two drying techniques (lyophilisation and hot air drying). In both cases, the fermentation led to noteworthy improvements in swelling and water holding capacity, especially in those lyophilised than those dried. In contrast, the emulsifying, foaming, thickening, and gelling capacities decreased significantly. The loss of abilities was more severe for dried grains than for lyophilized ones. The thermomechanical analysis of the fermented flours showed lower thickening and gelling potential compared to untreated flours. Microscopy images revealed that the state and structure of starch granules were affected by both fermentation and drying processes. Starch granules in lentils were partly pre-gelatinised and trapped in the cotyledon cell, resulting in limited thickening and gelling abilities. In contrast, in quinoa, starch underwent pre-gelatinisation and retrogradation during the fermentation process, promoting the production of resistant starch and increasing fibre content. This study presents the potential of treated flours as ingredients possessing unique attributes compared to protein and fibre-rich conventional products.

In Vitro Digestion Assessment (Standard vs. Older Adult Model) on Antioxidant Properties and Mineral Bioaccessibility of Fermented Dried Lentils and Quinoa.

The growing number of older adults necessitates tailored food options that accommodate the specific diseases and nutritional deficiencies linked with ageing. This study aims to investigate the influence of age-related digestive conditions in vitro on the phenolic profile, antioxidant activity, and bioaccessibility of minerals (Ca, Fe, and Mg) in two types of unfermented, fermented, and fermented dried quinoa and lentils. Solid-state fermentation, combined with drying at 70 °C, significantly boosted the total phenolic content in Castellana and Pardina lentils from 5.05 and 6.6 to 10.5 and 7.5 mg gallic acid/g dry weight, respectively, in the bioaccessible fraction following the standard digestion model, compared to the unfermented samples. The phenolic profile post-digestion revealed elevated levels of vanillic and caffeic acids in Castellana lentils, and vanillic acid in Pardina lentils, while caffeic acids in Castellana lentils were not detected in the bioaccessible fraction. The highest antioxidant potency composite index was observed in digested fermented dried Castellana lentils, with white quinoa samples exhibiting potency above 80%. Mineral bioaccessibility was greater in fermented and fermented dried samples compared to unfermented ones. Finally, the digestive changes that occur with ageing did not significantly affect mineral bioaccessibility, but compromised the phenolic profile and antioxidant activity.

Impact of Air-Drying Temperature on Antioxidant Properties and ACE-Inhibiting Activity of Fungal Fermented Lentil Flour.

Solid-state fermentation (SSF) with Pleurotus ostreatus enhances the nutritional value of legumes. However, drying can cause significant changes in physical and nutritional properties of the final products. Thus, this work studies the impact of air-drying temperature (50, 60, and 70 °C) on relevant properties (antioxidant properties, ACE-inhibitory capacity, phytic acid, colour, and particle size) of two fermented lentils flour (Pardina and Castellana) using freeze-drying as a reference method. Castellana variety is a better substrate for Pleurotus, generating four times more biomass. In addition, an almost total reduction of phytic acid from 7.3 to 0.9 mg/g db is achieved in this variety. Air-drying significantly decreased the particle size and the final colour with ΔE > 20; nonetheless, the temperature does not play a crucial role. SSF decreased the total phenolic content and the antioxidant capacity regardless of the variety, however, drying at 70 °C increased total phenolic content (186%) in fermented Castellana flour. Comparing drying methods, freeze-drying implied a higher decrease in those parameters, reducing the TPC from 2.4 to 1.6 and from 7.7 to 3.4 mg gallic acid/g db in Pardina and Castellana dried flours. Finally, the flours inhibit the angiotensin I-converting-enzyme, and fermentation and drying increased their potential cardiovascular benefits.

Understanding the role of food matrix on the digestibility of dairy products under elderly gastrointestinal conditions.

This study aimed to evaluate the effect of some elderly in vitro gastrointestinal (GI) conditions on proteolysis and lipolysis extent, calcium, vitamins A and D bioaccessibility and lactose release in milk, yogurt, fresh and aged cheeses. To evaluate the impact of the some oral, gastric and intestinal disorders appearing with ageing on dairy digestion, three in-vitro elderly models were applied (E1 (oral altered conditions), E2 (oral and gastric altered conditions) and E3 (oral, gastric and intestinal altered conditions)) plus a healthy adult one as control. Proteolysis extent was significantly affected by elderly GI alterations (p < 0.05) (around 40% of reduction compared to control), being fresh and aged cheese proteolysis the most affected with an important descrease in leucine release (18 and 25%, respectively). Calcium, vitamins A and D3 bioaccesibility and lactose release seemed not to be highly compromised in these models of elderly conditions; however, the micronutrients bioaccessibility was very dependent on dairy matrix's structure. Finally, the amount of the lipid hydrolyzed fraction of cheeses is not influenced in the investigated models.