Rosehips, particularly dog rose fruits (Rosa canina L.), are a great source of antioxidant compounds, mainly phenolics. However, their health benefits directly depend on the bioaccessibility of these compounds affected by gastrointestinal digestion. Thus, the purpose of this research was to study the impact of gastrointestinal and colonic in vitro digestions on the concentration of total and individual bioaccessible phenolic compounds from a hydroalcoholic extract of rosehips (Rosa canina) and also their antioxidant capacity. A total of 34 phenolic compounds were detected in the extracts using UPLC-MS/MS. Ellagic acid, taxifolin, and catechin were the most abundant compounds in the free fraction, while gallic and p-coumaric acids were the main compounds in the bound phenolic fraction. Gastric digestion negatively affected the content of free phenolic compounds and the antioxidant activity measured using the DPPH radical method. However, there was an enhancement of antioxidant properties in terms of phenolic content and antioxidant activity (DPPH (2,2-diphenyl-1-picrylhydrazyl): 18.01 ± 4.22 mmol Trolox Equivalent (TE)/g; FRAP (Ferric Reducing Antioxidant Power): 7.84 ± 1.83 mmol TE/g) after the intestinal stage. The most bioaccessible phenolic compounds were flavonols (73.3%) and flavan-3-ols (71.4%). However, the bioaccessibility of phenolic acids was 3%, probably indicating that most of the phenolic acids were still bound to other components of the extract. Ellagic acid is an exception since it presented a high bioaccessibility (93%) as it was mainly found in the free fraction of the extract. Total phenolic content decreased after in vitro colonic digestion, probably due to chemical transformations of the phenolic compounds by gut microbiota. These results demonstrated that rosehip extracts have a great potential to be used as a functional ingredient.

In this study, the total phenolic content, the antioxidant and antiproliferative activities of onion waste extracts were characterized. Some phenolic compounds present in the extracts were also identified and quantified by HPLC-DAD. Additionally, an in-silico analysis was performed to identify the phenolic compounds with the highest intestinal absorption and Caco-2 permeability. The onion extract possessed a high amount of phenolic compounds (177 ± 9 mg/g extract) and had an effective antioxidant capacity measured by ABTS, FRAP and DPPH assays. Regarding the antiproliferative activity, the onion extracts produced cell cycle arrest in the S phase with p53 activation, intrinsic apoptosis (mitochondrial membrane potential modification) and caspase 3 activation. Likewise, onion waste increased intracellular ROS with possible NF-kB activation causing a proteasome down regulation. In addition, the extracts protected the intestine against oxidative stress induced by H₂O₂. According to the in-silico analysis, these results could be related to the higher Caco-2 permeability to protocatechuic acid. Therefore, this study provides new insights regarding the potential use of these types of extract as functional ingredients with antioxidant and antiproliferative properties and as medicinal agents in diseases related to oxidative stress, such as cancer. In addition, its valorization would contribute to the circular economy.

Sulfur dioxide (SO₂), the main preservative in wine, may affect the sensory properties of the wines, as well as cause allergic reactions and headaches in sensitive people. The aim of this work was to evaluate the replacement of SO₂ in Tempranillo wines with Mazuelo grape stem products. Five Tempranillo red wines were elaborated: positive control (60 mg/L SO₂); negative control with no preservatives; Mazuelo extract (200 mg/L); Mazuelo extract combined with SO₂ (100 mg/L + 20 mg/L); and Mazuelo stem (400 mg/L). The oenological parameters, antioxidant capacity, total phenolic (TP), total flavonoids (TF) and total anthocyanins (TA) contents were determined. Additionally, individual phenols were analyzed by HPLC-DAD-FLD. The spectrophotometric analyses showed that the wines had similar antioxidant capacities and concentrations of TP and TF. However, TA was more affected by the lack of SO₂ as anthocyanins presented higher concentrations in positive control samples. The concentrations of individual phenols followed a similar path in all samples. Wines containing sulfites were more similar than the other treatments. However, these similarities were not reflected on the sensory analysis performed, as triangle test did not show differences between the wine with extract addition and the positive control wine. Therefore, Mazuelo stem extract could be a possible strategy for SO₂ replacement. Nevertheless, further studies are necessary to confirm the potential of grape stem extracts as wine preservative.

This study examined the composition and possible application of agroindustry byproducts and wild food plants extracts. Onion waste extracts were tested for their phenolic content, antioxidant, and antiproliferative activities. Rosehip extract, particularly from dog rose fruits (Rosa canina L.) was examined for how gastrointestinal and colonic in vitro digestions affected its concentration of bioaccessible phenolic compounds and antioxidant capacity. Mazuelo grape stem products were employed to explore the possibility of replacing sulphur dioxide (SO2), a common wine preservative, in Tempranillo wines. The findings suggest potential applications of onion waste extracts as functional ingredients with antioxidant and antiproliferative properties, particularly in oxidative stress-related diseases like cancer, while also promoting circular economy principles through waste valorisation. Rosehip extracts show potential as functional ingredients despite digestive impacts. As for the wines, the changes in the physic-chemical composition during storage did not influence the organoleptic characteristics. Sensory analysis through a triangle test did not reveal differences between wines with Mazuelo extract addition and the positive control, suggesting the potential of Mazuelo stem extract as a viable strategy for SO2 replacement. However, further research is needed to ascertain fully the effectiveness of the proposed uses of the studied extracts.

This work had the purpose of evaluating the efficiency of the pretreatment with alkaline hydrogen peroxide of pineapple bagasse in order to obtain fermentable sugars by applying acid and enzymatic hydrolysis to said residue. Four experimental designs were applied to study the best conditions for the pre-treatment. Total reducing sugars (TRS) concentration was the response and hydrogen peroxide concentration, time and temperature were the independent variables. The studies were conducted using pineapple bagasse with particle sizes of 20 mesh and 48 mesh. Acid saccharification, with 2.9% sulfuric acid (v/v), following the pre-treatment, yielded TRS concentrations that reached 0.094 g of TRS/g of raw bagasse for 20 mesh and 0.101 g of TRS/g of raw bagasse for 48 mesh. The enzymatic saccharification, with 9 FPU/g cellulase and 2% (m/v) of bagasse, reached 0.063 g of TRS/g of raw bagasse for both particle sizes. The peroxide concentration showed a significant influence, the use of high concentrations reduced the TRS output in both hydrolysis. With the results found in this work, it is possible to infer the feasibility of applying pineapple bagasse as a lignocellulosic raw material.