Phenolic composition and sensory dynamic profile of chocolate samples enriched with red wine and blueberry powders.

Cabernet Sauvignon (CS) and a combination of Cabernet Sauvignon with blueberry extract (CS + B), were spray dried (using maltodextrin DE10, 13.5% w/w as a carrier) to obtain two types of phenolic-rich powders. The addition of blueberry to CS increased phenolic compounds content by 16%. Eight chocolate formulations were obtained by modifying concentrations of cocoa solids, cocoa butter, and sugar. Six of the samples were added with 10% w/w of phenolic-rich powder, while two of them remained as powder-free controls. The anthocyanin and flavan-3-ol profiles of chocolates were determined by HPLC-DAD-MS and HPLC-MS, respectively. In addition, the sensory dynamic profile of samples was assessed by Temporal Dominance of Sensations with a consumer panel. Results showed that the addition of phenolic-rich powders produced a significant increase in the anthocyanin composition obtaining the highest anthocyanin content in the white chocolate added with CS + B powder. On the other hand, adding 10% of CS powder to dark chocolate (55% cocoa pellets) did not result in a significant increase in phenolic compounds. The addition of phenolic-rich powders to chocolates influenced visual color, texture, and taste, leading to new products with distinctive characteristics and increasing the possibility of using phenolic-rich powders as innovative and healthy ingredients.

In search for flavonoid and colorimetric varietal markers of Vitis vinifera L. cv Rufete wines.

The better adaptation of autochthonous grape varieties to environmental changes is increasing the interest on them. Previous studies on Vitis vinifera L. cv Rufete, the flagship of DOP "Sierra de Salamanca", demonstrated its phenolic potential to produce quality wines. The present study aims at discovering flavonoid (HPLC-DAD-MSn) and colorimetric (CIELAB) varietal markers in commercial Rufete wines (RW) that could be employed to discriminate them from those made with other varieties or mixtures. Compared to Tempranillo wines (TW), RW showed lower phenolic contents, with lower proportions of anthocyanins and flavonols but greater of flavanols. Principal Component Analysis applied to flavonoid and chromatic variables allowed varietal separation of the samples along PC2, which was mostly driven by %total prodelphinidins, %oligomeric procyanidins and C ab * (greater in TW) and by %monomeric procyanindins and L* (greater in RW) and, additionally, by the proportions of A-type vitisins, acetaldehyde-related pigments, quercetin 3-O-glucuronide and Quercetin/Myricetin ratio (all greater in RW). The results of the present study show that the typicity of Rufete grapes is quite preserved in the wines made with up to 95% of Rufete and 5% of Tempranillo grapes or wines and independently of the enological practices of the different wineries.

Gastrointestinal fate of phenolic compounds and amino derivatives from the cocoa shell: An in vitro and in silico approach.

The objective of this study was to assess how in vitro gastrointestinal digestion influenced the bioaccessibility and potential bioavailability of phenolic compounds and methylxanthines in thecocoa shell (CS) in the form of flour (CSF) and aqueous extract (CSE). To comprehend how these phytochemicals behaved during gastrointestinal digestion, we also modeled in silico the colonic microbial biotransformation of the phenolic compounds in the CS. Different groups of phenolic compounds (mainly gallic andprotocatechuic acids, and catechin) and methylxanthines (theobromine and caffeine)could be found in the CS. Methylxanthines and phenolic compounds were released differently during gastrointestinal digestion. Whereas digestion triggered the release of hydroxybenzoic acids (67-73%) and flavan-3-ols (73-88%) during the intestinal phase, it also caused the degradation of flavonols and flavones. Besides, the release of phytochemicals was significantly influenced by the CS matrix type. Phenolic compounds were protected by the CSF matrix. Phenolic acids from CSF were more bioaccessible in the intestinal (1.2-fold, p < 0.05) and colonic (1.3-fold, p < 0.05) phases than those from the CSE. Methylxanthines were also more bioaccessible in the intestinal (1.8-fold, p < 0.01) and colonic phases (1.3-fold, p < 0.001) and bioavailable (1.8-fold, p < 0.001) in the CSF. Colonic metabolism demonstrated that the gut microbiota could biotransform non-absorbed phenolic compounds into other lower molecular weight and more bioavailable metabolites. These findings support the CS's potential as a source of bioaccessible, bioavailable, and active phytochemicals.

Understanding the Gastrointestinal Behavior of the Coffee Pulp Phenolic Compounds under Simulated Conditions.

Numerous residues, such as the coffee pulp, are generated throughout coffee processing. This by-product is a source of antioxidant phytochemicals, including phenolic compounds and caffeine. However, the antioxidant properties of the phenolic compounds from the coffee pulp are physiologically limited to their bioaccessibility, bioavailability, and biotransformation occurring during gastrointestinal digestion. Hence, this study explored the phenolic and caffeine profile in the coffee pulp flour (CPF) and extract (CPE), their intestinal bioaccessibility through in vitro digestion, and their potential bioavailability and colonic metabolism using in silico models. The CPE exhibited a higher concentration of phenolic compounds than the CPF, mainly phenolic acids (protocatechuic, chlorogenic, and gallic acids), followed by flavonoids, particularly quercetin derivatives. Caffeine was found in higher concentrations than phenolic compounds. The antioxidant capacity was increased throughout the digestive process. The coffee pulp matrix influenced phytochemicals' behavior during gastrointestinal digestion. Whereas individual phenolic compounds generally decreased during digestion, caffeine remained stable. Then, phenolic acids and caffeine were highly bioaccessible, while flavonoids were mainly degraded. As a result, caffeine and protocatechuic acid were the main compounds absorbed in the intestine after digestion. Non-absorbed phenolic compounds might undergo colonic biotransformation yielding small and potentially more adsorbable phenolic metabolites. These results contribute to establishing the coffee pulp as an antioxidant food ingredient since it contains bioaccessible and potentially bioavailable phytochemicals with potential health-promoting properties.

Monitoring the effects and side-effects on wine colour and flavonoid composition of the combined post-fermentative additions of seeds and mannoproteins.

One of the main consequences of the advancement of harvest date associated to global climate change is that the phenolic maturity of grapes can be delayed in relation to their technological maturity. As a consequence, wines made from these grapes can be poor in phenolic compounds or possess an unbalanced phenolic composition, affecting their global quality. The combined post-fermentative addition of seeds and an astringency-modulator mannoprotein (MP) might be a potential strategy to solve this problem, since seeds might supply flavanols and improve wine chemical stability and the mannoprotein might modulate the changes induced in astringency by the addition of seeds and improve wine colloidal stability. The present study aimed at monitoring at different moments of winemaking and ageing the effects and side-effects of this combined strategy on the detailed flavanol, flavonol and anthocyanin compositions and on colour of wines made from Syrah grapes. Seeds were obtained from Pedro Ximénez overripe grapes. Flavanol composition and flavonol and anthocyanin compositions were determined by HPLC-MSn-MRM and HPLC-DAD-MSn analyses, respectively. Colour changes caused by these additions were studied from CIELAB parameters as well as the ability of these techniques to protect colour from bleaching agents, such as SO2. In general, the addition of seeds initially increased the levels of flavanols and anthocyanins. However, during bottle ageing a reduction in the levels of flavanols, flavonols and anthocyanins could be observed in seed treated wines, which might be related to the greater formation of flavanol aggregates associated with greater levels of flavanols. This effect was partially solved for most of the flavonoids studied with the additional MP treatment. Treated and control wines showed colour differences that were visible to human eye, although they were reduced over time. At the end of the study, treated wines showed colour parameters corresponding to younger wines than those observed in control wines. A greater resistance against SO2 bleaching was also observed in treated wines, which can be mainly associated to the greater percentages of polymeric pigments caused by seed treatment and to the improvement of the colloidal stability of SO2-resistant pigments caused by the addition of the MP.

Addition of Mannoproteins and/or Seeds during Winemaking and Their Effects on Pigment Composition and Color Stability.

The increase of temperature can cause a decoupling of sugar and anthocyanin accumulation in grapes, leading to wines poor in color. Different enological techniques are nowadays under study to overcome this problem. Among them, the present study has evaluated the color and pigment composition modifications caused by the addition during Syrah winemaking of either Pedro Ximénez seeds (intended to increase chemical stability) or/and two different mannoproteins (color-protective and astringency-modulator) to increase colloidal stability. Color and pigment composition modifications were assessed from CIELAB color parameters and from HPLC-DAD-MS n results before and after cold-treatment (used to force colloidal instability). The addition of both seeds and mannoproteins increased color stability against cold and, additionally, against SO2-bleaching in the case of mannoproteins. However, the initial pigment composition and color of the samples were differently affected by these additions, being clearly affected (Δ E* ab > 3) in the cases of seeds and with the astringency-modulator mannoprotein and hardly modified with the other one.