Ana Aguilar-Galvez

Plant-based symbiotic systems are often limited by poor storage stability and inconsistent biofunctional performance. This study evaluated the stability and functionality of a fermented blend based on sacha inchi (Plukenetia volubilis) oil press cake (SIC) and yacon (Smallanthus sonchifolius) flour (YF) as sources of protein and fructooligosaccharides (FOS), respectively, using two processing strategies: fermentation with Lactobacillus rhamnosus (T1) and combined enzymatic hydrolysis with Alcalase and fermentation with Lactobacillus plantarum (T2). Both treatments maintained viable cell counts (VCC) above probiotic thresholds (>10⁶ CFU mL⁻¹) during 28 days of storage at 4 °C, confirming their suitability as probiotic carriers. Notably, T2 significantly enhanced metabolic activity, as evidenced by higher organic acid production and increased soluble protein content due to Alcalase-mediated hydrolysis, which promoted the generation of bioactive peptides associated with improved antioxidant and antihypertensive activities. Biofunctional properties, including total phenolic content, antioxidant capacity (AC), and angiotensin-converting enzyme (ACE) inhibitory activity, remained stable throughout storage, while FOS degradation was minimal, confirming preservation of prebiotic functionality. LC–MS/MS Q-TOF analysis revealed a complex phenolic profile that was differentially modulated by lactic acid fermentation, with L. plantarum (T2) promoting extensive phenolic biotransformation and increased metabolite diversity, whereas L. rhamnosus (T1) largely preserved the original phenolic profile. These findings demonstrate that the synergistic interaction between enzymatic hydrolysis and L. plantarum fermentation promoted peptide release, intensified microbial metabolism, and enhanced phenolic biotransformation, thereby contributing to the superior functional properties observed in T2, while maintaining stable biofunctional characteristics throughout refrigerated storage in both treatments.

In this study, the formation of Maillard reaction products (MRPs), namely acrylamide (AA) and fluorescent advanced glycation end products (f-AGEs), was evaluated in four quinoa and four cañihua flours subjected to heating at 185 °C. The influence of endogenous phenolic compounds and the addition of tara hydrolyzed gallotannins on MRPs formation was investigated. Varieties with higher quercetin and rutin contents showed lower AA and f-AGEs formation. AA formation kinetics differed between species, increasing with heating time in quinoa, whilst decreasing after 20 min in cañihua. Maximum AA levels ranged from 18.6 to 87.0 μg/kg, remaining below the EU benchmark value for non-wheat-based bread (300 μg/kg). Compared with the Asn–Glc control system, flour systems reduced AA formation by approximately 18.7 to 60.3%, while tara hydrolyzed extract further enhanced inhibition, reaching reductions above 72.7 to 96.2%. Similar trends were observed for f-AGEs, with mitigation levels up to 54.1 to 77.4%. Cañihua varieties showed higher AA inhibition capacity than quinoa, likely associated with differences in phenolic composition and antioxidant capacity. These findings demonstrate the potential of Andean pseudocereals and tara-derived polyphenols as natural strategies to mitigate thermally induced contaminants in processed foods.

This study evaluated the iron-chelating capacity (ICC) of Lupinus mutabilis protein hydrolysate (LMPH) and its peptide fractions obtained through ultrafiltration and purification by immobilized metal ion affinity chromatography (IMAC) and gel filtration chromatography (GFC). Peptides were identified by LC-MS/MS, and their interactions with Fe²⁺ were analysed using molecular docking. LMPH was produced by enzymatic hydrolysis with Alcalase and subsequently subjected to ultrafiltration to concentrate peptides smaller than 2 kDa. This fraction exhibited higher ICC (35.1 mg Fe²⁺·g⁻¹) than the hydrolysate (22.75 mg Fe²⁺·g⁻¹). Sequential purification by IMAC and GFC yielded peptide fractions with enhanced ICC values (45.20 and 13.51 mg Fe²⁺·g⁻¹). A total of 176 peptides were identified by de novo LC-MS/MS sequencing, from which nine were selected based on favourable structure–ICC relationships and absence of predicted toxicity. Molecular docking analysis suggested spatial proximity between Fe²⁺ and the selected peptides. Although stable multi-site binding was not predicted under the applied computational model, the results support the potential of these sequences to interact with Fe²⁺. These findings provide molecular and chemical insights supporting the iron-binding potential of LMPH-derived peptides and highlight their future potential as functional ingredients for preventing and managing iron deficiency.

The present study evaluated the performance of some enzymatic and non-enzymatic antioxidant systems against oxidative stress for 10 to 30 d of refrigeration (R) and 15 to 50 d in controlled atmosphere (CA) conditions in both exocarp and mesocarp of Hass avocados from early and late harvests and at shelf life (SL) or consumption maturity. The possible relationship of the antioxidant systems with the occurrence of physiological disorders is also evaluated. The results indicate that the enzymatic system—superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), phenylalanine ammonium lyase (PAL) and polyphenoloxidase (PPO)—as well as the non-enzymatic system—such as phenolic compounds (PC)—showed different responses to the stress generated during storage and shelf life. In general, SOD, CAT, PAL and PPO did not significantly vary in storage (R or CA). At consumption maturity, SOD, POD and PAL activities decreased in the mesocarp (RSL and CASL), while CAT increased in the exocarp for CASL15-50d. PC instead decreased in the exocarp as the harvest period progressed while it increased in the mesocarp. Physiological disorders (dark spots) showed only in refrigeration on the exocarp at R30d and in mesocarp at RSL30d coincident with low SOD and low SOD and POD activity values, as well as low PC contents (p-coumaric and its derivatives and caffeic acid derivatives), respectively. The results support the use of CA as a postharvest technology to prevent the development of physiological disorders through the joint action of antioxidative defenses during avocado transport to distant markets until consumption maturity is reached.

Summary: The present research aimed to evaluate three peptides synthesised from tarwi: AVPFWM, YSGWLGL and AHAGFGMLY in their antioxidant, antihypertensive and hypoglycemic properties, using in vitro and in silico studies, this last one considering the molecular docking evaluation and ADMET (absorption, distribution, metabolism, excretion and toxicity) properties. The in vitro results found ABTS and ORAC antioxidant capacity values between 2.12 and 3.94 and 1.64 and 3.10 μmol TE/μmol of peptide, respectively, while the IC₅₀ values for angiotensin‐converting enzyme (ACE) and dipeptidyl peptidase IV (DPP‐IV) inhibition ranged between 0.14 and 6.38 μM and 16.4 and 1140.0 μM, respectively. The molecular docking study performed between peptides and ACE and DPP‐IV enzymes, showed affinity towards both enzymes establishing molecular interactions at the level of the active site of both enzymes through hydrogen bonds and hydrophobic interactions. This study together with the in vitro study highlight the YSGWLGL peptide for the favourable results found. Finally, the predicted ADMET properties of the three peptides suggest that they have the potential for absorption, appropriate distribution, no participation in the metabolism of P450 enzymes and no toxicity concerns. It is concluded that tarwi peptides may be a valuable source for developing nutraceuticals, functional ingredients or supplements.

Colored potatoes have been of interest because of their nutritional and health-promoting properties. However, their aptitude for processing regarding acrylamide formation levels is highly variable and for the most part unknown. In this work, the effect of cultivation season (summer and winter), and postharvest cold storage (1, 2, and 5 months at 5 °C ± 1 °C) on the Maillard reaction precursors (reducing sugars, sucrose, and asparagine), phenolic compounds (anthocyanins, phenolic acids and other flavonoids), and acrylamide after frying (GC-MS) were assessed on the “Michuñe negra” potato cultivar from the southern region of Chile grown under fertigation. Acrylamide levels were surveyed on six samples of commercial colored potato chips for comparison purposes. Cultivation season and cold storage showed an effect on both main primary and secondary metabolites. The amount of reducing sugars such as fructose increased with cold storage. Anthocyanin and phenolic contents were higher in the winter season and increased with cold storage. Acrylamide levels were high, surpassing the EFSA benchmark value (750 µg kg⁻¹) in all cases, notably in chips made after one month of cold storage (2125% higher). Additional measures in both agronomical and processing stages of the purple-fleshed potato need to be implemented to lower the acrylamide levels down to acceptable values.

Summary: Some bioactive compounds in paico (Dysphania ambrosioides)leaves were characterised. By LC–MS/MS‐QToF, 20 polyphenols were found: vanillic acid, onep‐coumaroyl‐hexoside acid derivative, three quercetin‐rhamnoside derivatives, one quercetin derivative, two kaempferol acetyl‐furanoside‐rhamnoside derivatives and twelve kaempferol‐rhamnoside derivatives. The content of total phenolic compounds was 645.11 mg/100 g dry weight (DW) of which the highest content corresponded to kaempferol glycosides. Likewise, in the analysis of terpenes, α‐terpinene, limonene,p‐cymene, thymol, γ‐terpinene, carvacrol, isoascaridol and α‐pinene were found in amounts of 1489.65; 313.1; 104.8; 49.4; 45.1; 22.9; 8.19 and 4.32 mg/100 g DW, respectively. Analysis of lipophilic metabolites reported fatty acids in order of importance: linoleic = linolenic > palmitic > oleic (35.8; 35.4; 26.3 and 2.5%, respectively). α‐, β‐, γ‐ and δ‐tocopherols were found in amounts of 28.78, 7.19, 7.96 and 3.27 μg g⁻¹, respectively. It is concluded that paico leaves of Peruvian origin present a varied source of bioactive compounds with potential applications for the pharmaceutical and food industry.

Summary: Tarwi is an Andean grain, belonging to the legume group and is characterised by its high protein content, exceeding that reported in soybeans being an interesting resource for obtaining bioactive peptides. The tarwi protein hydrolysate (TPH) obtained by enzymatic hydrolysis with Alcalase (60 min) followed by Neutrase (120 min) presented important multifunctional properties to cope with oxidative stress, hypertension and diabetes. After concentration and purification process the most active fraction containing the highest antioxidant, antihypertensive (inhibition of angiotensin‐converting enzyme I, ACE) and antidiabetic (inhibition of dipeptidyl peptidase IV, DPP IV) properties were found in the low‐molecular weight peptide fraction. Thus, this last fraction was subjected to a de novo sequencing LC–MS/MS analysis yielding the identification of 25 peptides, with potential activities as ACE and DPP IV inhibitors and antioxidative according to BIOPEP database. Of these, four novel peptides: AVPFWM, YSGWLGL, AHAGFGMLY and FFSMKVM, stood out for their relatively high scores in bioactivity predicted by Peptide Ranker, additionally the structure–activity evaluation performed on them, supported the predicted antioxidant, antihypertensive and antidiabetic properties. These results demonstrated that TPH might be considered a potential source of peptides with multifunctional bioactive properties with possibilities of application in the food and nutraceutical sectors.