Hydrothermal Treatment Effect on Antioxidant Activity and Polyphenols Concentration and Profile of Brussels sprouts (Brassica oleracea var. gemmifera) in an In Vitro Simulated Gastrointestinal Digestion Model

Iodine enriched kale (Brassica oleracea var. sabellica L.)-The influence of heat treatments on its iodine content, basic composition and antioxidative properties

Iodine deficiency in the diet globally continues to be a cause of many diseases and disabilities. Kale is a vegetable that has health-promoting potential because of many nutrients and bioactive compounds (ascorbic acid, carotenoids, glucosinolates and phenolic compounds). Brassica vegetables, including kale, have been strongly recommended as dietary adjuvants for improving health. The nutrient and health-promoting compounds in kale are significantly affected by thermal treatments. Changes in phytochemicals upon such activities may result from two contrary phenomena: breakdown of nutrients and bioactive compounds and a matrix softening effect, which increases the extractability of phytochemicals, which may be especially significant in the case of iodine-fortified kale. This study investigated changes of basic composition, iodine, vitamin C, total carotenoids and polyphenols contents as well as antioxidant activity caused by steaming, blanching and boiling processes in the levels of two cultivars of kale (green and red) non-biofortified and biofortified via the application to nutrient solutions in hydroponic of two iodoquinolines [8-hydroxy-7-iodo-5-quinolinesulfonic acid (8-OH-7-I-5QSA) and 5-chloro-7-iodo-8-quinoline (5-Cl-7-I-8-Q)] and KIO3. Thermal processes generally significantly reduced the content of the components in question and the antioxidant activity of kale, regardless of cultivar and enrichment. It was observed that the red cultivar of kale had a greater ability to accumulate and reduce iodine losses during the culinary processes. 8-hydroxy-7-iodo-5-quinolinesulfonic acid showed a protective effect against the treatments used, compared to other enrichments, thus contributing to the preservation of high iodine content.

In Vitro Digestion of Polyphenolic Compounds and the Antioxidant Activity of Acorn Flour and Pasta Enriched with Acorn Flour

Acorn flour is a rich source of nutrients and is beneficial to human health due to, among other things, its low glycemic index and polyphenol content. In order to obtain more accurate data on the levels and activities of the substances tested after ingestion and digestion, it may be beneficial to use a simulated in vitro digestion method. Therefore, the objective of the present study was to elucidate the content of polyphenols, individual phenolic acids, flavonoids and antiradical properties of acorn flour and pasta enriched with acorn flour before and after simulated in vitro gastrointestinal digestion. The results indicate that the total polyphenol content (TPC), flavonoid content and radical scavenging activity exhibited an increasing trend following the initial digestion stage and a decreasing trend following the second stage. Nevertheless, the levels of phenolic acids demonstrated an increase in both digestion phases. The digestion processes of polyphenols in acorn flour differ significantly from those in pasta. In the case of pasta, total polyphenols, phenolic acids and flavonoids, as well as free radical scavenging properties, demonstrated a decreasing trend following each digestion stage.

Modern and traditional cooking methods affect the antioxidant activity and phenolic compounds content of Trachystemon Orientalis (L.) G. Don

Trachystemon orientalis (L.) G. Don is a medicinal plant with beneficial effects on human health. Its antioxidant and phenolic compound content is higher than most natural plants. This is the first study on the cooking of this consumed plant. This study investigated how different cooking methods and times affect the antioxidant activity and phenolic compound content of Trachystemon orientalis (L.) G. Don. The Folin-Ciocalteu method (FCR), ferric-reducing antioxidant power (FRAP), copper-reducing antioxidant capacity (CUPRAC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were used to evaluate the antioxidant activity and total phenolic content (TPC). Phenolic compounds were also determined by high-performance liquid chromatography (HPLC). Microwave cooking, stir-frying and sous vide increased TPC and antioxidant activity (p<0.05). Steaming decreased TPC and antioxidant activity (p<0.05). It was determined that the best cooking method and time was stir-frying for 15 minutes (TPC, CUPRAC and FRAP values 45.18±3.91 mg GAE/g DW, 15559.39±106.90 mmol Troloks/g DW and 555.10±24.05 μmol Fe (II)/g DW, respectively). Raw Trachystemon orientalis (L.) G. Don was detected with caffeic acid (31.53±0.25 mg/100 g DW). New phenolic compounds (protocatechuic acid and p-coumaric acid) were formed by boiling, stir-frying, microwaving, and sous vide methods. In conclusion, regarding antioxidant activity and phenolic compounds of Trachystemon orientalis (L.) G. Don; the best cooking methods are microwave, stir-frying, and sous vide (p<0.05). The most wrong cooking method is steaming (p<0.05).

The Impact of Culinary Processing, including Sous-Vide, on Polyphenols, Vitamin C Content and Antioxidant Status in Selected Vegetables-Methods and Results: A Critical Review

This study presents various research methods and results analysis of the total antioxidant status (TAS), polyphenols content (PC) and vitamin C content in selected plant materials (vegetables) subjected to various technological processes, including sous-vide. The analysis included 22 vegetables (cauliflower white rose, romanesco type cauliflower, broccoli, grelo, col cabdell cv. pastoret, col lllombarda cv. pastoret, brussels sprouts, kale cv. crispa-leaves, kale cv. crispa-stem, toscana black cabbage, artichokes, green beans, asparagus, pumpkin, green peas, carrot, root parsley, brown teff, white teff, white cardoon stalks, red cardoon stalks and spinach) from 18 research papers published in 2017 to 2022. The results after processing by various methods such as conventional, steaming and sous-vide cooking were compared to the raw vegetable results. The antioxidant status was mainly determined by the radical DPPH, ABTS and FRAP methods, the polyphenol content by the Folin-Ciocalteu reagent and the vitamin C content using dichlorophenolindophenol and liquid chromatography methods. The study results were very diverse, but in most studies, the cooking techniques contributed to reducing TAS, PC and vitamin C content, with the sous-vide process being most beneficial. However, future studies should focus on vegetables for which discrepancies in the results were noted depending on the author, as well as lack of clarity regarding the analytical methods used, e.g., cauliflower white rose or broccoli.

Changes in the Bioaccessibility of Antioxidants after Simulated In Vitro Digestion of Bioprocessed Spelt-Enhanced Wheat Bread

The aim of the study was to determine whether the partial replacement of wheat flour with bioprocessed spelt flour contributes to a higher bioaccessibility of the antioxidants in bread. The results showed that the type and amount of bioprocessed spelt flour in a bread recipe has a major impact on the extractable and bound TPC, the content of individual phenolics, their antioxidant activity, and their bioaccessibility as determined by in vitro digestion. Extractable p-coumaric and trans-ferulic acids in breads decreased after digestion, while extractable cis-ferulic and p-hydroxybenzoic acids increased. The bioaccessibility of TPC in the control bread (100% wheat flour), and in bread enriched with 5% "germinated + fermented" spelt flour (GFB5), did not differ. However, the digested GFB5 bread contained 5.2-times more extractable, and 1.3-times more bound, trans-ferulic acid than the digested control bread. trans-Ferulic acid showed the lowest bioaccessibility, up to 2.8%. In GFB2.5 and GFB5 breads, the bioaccessibility of p-coumaric, trans-ferulic, and cis-ferulic acids was higher than in other digested breads. PCA visualized the difference between the undigested and digested breads. The incorporation of germinated and fermented, or germinated and enzymatic, treated spelt flour in a white bread recipe could be an attractive way of providing consumers with nutritionally interesting foods.

The Effect of In Vitro Digestion on Polyphenolic Compounds and Antioxidant Properties of Sorghum (Sorghum bicolor (L.) Moench) and Sorghum-Enriched Pasta

The phenol content of sorghum is a unique feature among all cereal grains; hence this fact merits the special attention of scientists. It should be remembered that before polyphenols can be used in the body, they are modified within the digestive tract. In order to obtain more accurate data on the level and activity of tested ingredients after ingestion and digestion in the in vivo digestive tract, in vitro simulated digestion may be used. Thus, the aim of this study was to determine the content of polyphenols, flavonoids, and individual phenolic acids, as well as the antiradical properties, of sorghum and sorghum-enriched pasta before and after in vitro simulated gastrointestinal digestion. We observed that the total content of polyphenols decreased after gastric digestion of sorghum, and slightly increased after duodenal digestion. Moreover, the flavonoid content decreased after the first stage of digestion, while antioxidant properties increased after the first stage of digestion and slightly decreased after the second stage. The digestion of polyphenolics in sorghum is completely different to that in pasta-both in varieties with, and without, the addition of sorghum. For pasta, the content of total polyphenols and flavonoids, and free radical scavenging properties, decrease after each stage of digestion.

Effect of the Production Parameters and In Vitro Digestion on the Content of Polyphenolic Compounds, Phenolic Acids, and Antiradical Properties of Innovative Snacks Enriched with Wild Garlic (Allium ursinum L.) Leaves

A new type of corn snack has been created containing additions of wild garlic (Allium ursinum L.). This medicinal and dietary plant has a long tradition of use in folk medicine. However, studies on wild garlic composition and activity are fairly recent and scarce. This research aimed to investigate the influence of the screw speed and A. ursinum amounts on the antiradical properties as well as the content of polyphenolic compounds and individual phenolic acids of innovative snacks enriched with wild garlic leaves. The highest radical scavenging activity and content of polyphenols and phenolic acids were found in the snacks enriched with 4% wild garlic produced using screw speed 120 rpm. The obtained findings demonstrated that snacks enriched with wild garlic are a rich source of polyphenolic compounds. Since the concentration of such compounds is affected by many factors, e.g., plant material, presence of other compounds, and digestion, the second aim of this study was to determine radical scavenging activity, the content of polyphenols, and individual phenolic acids of snacks after in vitro simulated gastrointestinal digestion. Using an in vitro two-stage model, authors noted a significant difference between the concentration of polyphenolic compounds and the polyphenol content of the plant material before digestion.

Simulated Gastrointestinal Digestion of Bioprocessed Spelt Seeds: Bioaccessibility and Bioactivity of Phenolics

The goal of this research was to evaluate the impact of different bioprocessing techniques on improved bioaccessibility of phenolics from spelt seeds. Despite the negative influence of gastrointestinal digestion, fermentation of germinated seeds significantly increased the bioaccessibility of total phenolics and their antioxidant activity compared to digested raw seeds. Enzymatic treated fermented seeds showed the highest relative bioaccessibility of p-coumaric and trans-ferulic acids, while their absolute contents were significantly higher in “germinated + fermented” seeds. Our research suggests that pretreatment of spelt seeds with hydrolytic enzymes improves access of fermenting microorganisms to structural elements, resulting in an increased content of extractable and bound trans-ferulic acid. Significantly higher biostability of phenolics was observed in raw seeds. Some major quality changes in the composition of extracts were observed under simulated in vitro digestion, since antioxidants of the same extract showed a different relative decrease in DPPH• and ABTS•+ scavenging activities compared to the raw seeds or their corresponding undigested counterparts. It is therefore important to increase the content of extractable antioxidants in seeds by bioprocessing, since they are strongly diminished during digestion.