RESUMO
The quality of wine grapes and wine depends on their content of phenolic compounds. Under commercial conditions, the phenolic maturity of grapes is mostly achieved by applying abscisic acid analogues. Some Ca forms represent a cost-effective alternative for these compounds. In this study, 'Shiraz' vines (veraison of 90%) were sprayed with CaCO3-rich residues from the cement industry (4.26 g of Ca per L). Fruit from treated and untreated vines was harvested 45 days after CaCO3 spraying and evaluated for quality. The fruit was vinified, and the obtained wines were bottled and stored in darkness for 15 months at 20 °C. Wines were evaluated for quality after storage. The evaluation of grape and wine quality included the content of phenolic compounds and antioxidant capacity. The treatment with CaCO3 did not affect the ripening rate of grapes. However, the treatment improved the fruit yield as well as the color development, the content of phenolic compounds, and antioxidant capacity of grapes and wine. The treatment favored especially the accumulation of malvidin-3-O-glucoside, pelargonidin-3-O-glucoside, caftaric acid, caffeic acid, trans-cinnamic acid, quercetin, catechin, epicatechin, resveratrol, and the procyanidins B1 and B2. Wine made with treated fruit was of higher quality than that of control fruit.
RESUMO
There is uncertainty about the identity of digestive metabolites of anthocyanins because many are naturally present in foods and/or are formed from other phenolic compounds during the digestive process. Studies using pure anthocyanins are needed to clarify this uncertainty. In this study, selected anthocyanins were purified from common fruits and individually subjected to gastric and small intestinal digestion in vitro to determine their stability, metabolites generated and bioaccessibility. Anthocyanins were highly stable during the gastric phase of simulated digestion (p > 0.05). The recovery of anthocyanins decreased during the small intestinal phase of digestion (p < 0.05). Stability was dependent on anthocyanidin structure and type of glycation (p < 0.05). Gastric and gastrointestinal phases mainly contained anthocyanins as bioaccessible flavylium cations and chalcones. Expected anthocyanin metabolites (i.e., phenolic acids and phoroglucinaldehyde) were not detected in chyme. Deglycation of anthocyanins during simulated digestion was quite limited and the bioaccessibility of intact anthocyanins was very low (0.07-2.21%).
Assuntos
Antocianinas , Frutas , Antocianinas/análise , Digestão , Frutas/química , Trato Gastrointestinal/metabolismo , Fenóis/análiseRESUMO
Dried fruit pulp and oil from avocado fruit (Persea americana, Cv Hass) at five different ripening stages were digested in vitro to determine the bioaccessibility of several fat-soluble bioactive compounds (FSBC). Viscosity, particle size, ζ-potential and lipolysis were evaluated and related to the bioaccessibility of the tested compounds. Fatty acids were more bioaccessible than carotenoids and tocopherols. The viscosity of gastrointestinal medium was related to the initial fruit firmness and modulated the bioaccessibility of neoxanthin, violaxanthin, lutein and luteoxanthin, while particle size and ζ-potential influenced the bioaccessibility of fatty acids. Lipolysis degree highly altered the bioaccessibility of luteoxanthin, pheophytin b, and α-tocopherol indicating that these digestive events are highly involved in the bioaccessibility of FSBC. In summary, FSBC from avocado fruit are highly bioaccessible, but their bioaccessibility depends on fruit ripening stage and FSBC type and concentration.
Assuntos
Persea , Carotenoides , Ácidos Graxos , Frutas , TocoferóisRESUMO
Jalapeño peppers at intermediate ripening stages (IRS) are typically discarded at the packinghouse because they are not demanded for fresh consumption or industrial processing. These peppers have been scarcely studied in terms of pigment composition and bioactivity. In this study, the profile of pigments (carotenoids and chlorophylls) and antioxidant activity were determined in raw and heat-processed Jalapeño peppers at three IRS (brown, 50% red, and 75% red). Peppers contained 64 different pigments. Chlorophylls were the most abundant pigments in raw brown peppers while capsanthin was the most abundant at the other IRS. The content of most pigments decreased due to heat treatments. Several pheophytins and cis isomers of carotenoids were generated by heat processing. Boiling and grilling consistently decreased and increased the antioxidant activity of peppers, respectively. Tested peppers showed a more complex/abundant pigment content and higher antioxidant activity than those typically reported for green and red peppers.
Assuntos
Antioxidantes/química , Capsicum/química , Capsicum/crescimento & desenvolvimento , Carotenoides/química , Clorofila/química , Verduras/química , Culinária/métodos , Isomerismo , Xantofilas/químicaRESUMO
Raw and heat-processed (boiled and grilled) jalapeño peppers at three intermediate ripening stages (brown, 50% red, and 75% red) were digested in vitro without fat and in the presence of soybean oil (SO) or beef tallow (BT), and the micellarization of their lipid soluble pigments (LSP) was measured. The micelles from digestions with brown, 50% red, and 75% red peppers contained up to 27, 35, and 29 different LSP, respectively. Boiling and grilling decreased the micellarization of LSP from brown peppers, whereas the opposite was observed with 75% red peppers. Heat processing did not clearly affect the micellarization of LSP from 50% red fruits. The impact of fat on LSP micellarization was ripening-dependent, but the micellarization of the less polar carotenoids was always increased by SO or BT. This positive effect of fat was higher with SO than with BT.
Assuntos
Capsicum/química , Culinária/métodos , Gorduras/química , Pigmentos Biológicos/química , Verduras/química , Capsicum/crescimento & desenvolvimento , Carotenoides/química , Frutas/química , Frutas/crescimento & desenvolvimento , Temperatura Alta , Verduras/crescimento & desenvolvimentoRESUMO
Organic strawberry fruits (Cv. 'Albion') were harvested at six different ripening stages and evaluated for physical and chemical parameters. Biometrical characteristics and moisture content did not change significantly during ripening. Total soluble solids, pH and colour development increased while titratable acidity and fruit firmness decreased 14.7% and 91%, respectively. Fructose, glucose, and sucrose followed similar tendencies. Final contents of these sugars were 2323.4, 1988.5, and 1578.4 mg/100 g. Citric, malic, and ascorbic acids followed a descending, irregular, and increasing tendency during ripening, respectively. Final contents of these acids were 822.8, 245.8, and 78.1 mg/100 g. Total anthocyanins content (TAC) increased during ripening, while the opposite was observed for total phenolic content (TPC). TAC and TPC in ripe fruit were 56.4 mg/100g and 196 mg gallic acid equivalents (GAE)/100 g. Twenty eight phenolic compounds, mainly glycosides, were identified and quantified by HPLC-DAD-MS analysis. The concentration of these compounds was ripening dependent.