Bread enriched with Chenopodium quinoa leaves powder – The procedures for assessing the fortification efficiency

Raspberry Pomace as a Good Additive to Apple Freeze-Dried Fruit Bars: Biological Properties and Sensory Evaluation

This study investigated the impact of adding raspberry pomace to the phenolic content and biological properties of freeze-dried apple/raspberry bars. The bars were prepared by replacing apple puree with raspberry pomace (5-50%), and their phenolic compounds were assessed using ethanol and buffer extracts. This work also explored the potential bioaccessibility of phenolic compounds in enriched bars through a simulated digestion process (digest). Antioxidant, anti-inflammatory (LOX, COX-2 inhibition), antihypertensive (ACE inhibition), and antiproliferative effects on AGS and HT-29 cancer cells were evaluated. The total polyphenol content was highest in the all bar variants post-digestion. The highest-904.26 ± 23.5 mg/100 g-was determined for the B50 sample In the enriched bars, the concentration of chlorogenic acid decreased from 6.99 ± 1.08 mg/L for BP5 to 2.75 ± 0.32 mg/L for BP50, but the ellagic acid concentration increased from 1.46 ± 0.02 mg/L for BP5 to 12.73 ± 0.09 mg/L for BP50. Among the tested extracts, the highest antioxidant and LOX, COX-2 inhibiting activity was determined for digest. The ability to neutralize free radicals increased with raspberry pomace addition from 3.63 ± 0.26 mM TE/100 g for BC to 5.58 ± 0.22 mM TE/100 g for the BP50 sample. ACE inhibition was quite similar for ethanolic and digest extracts, but much weaker for buffer extracts. The lowest EC50 value was 1.04 ± 0.03 mg/mL for the BP30 ethanolic sample. Analyzed extracts showed antiproliferative activity against both tested cell lines. The EC50 values for HT-29 cancer cells decreased from 0.354 ± 0.031 mg/mL for BC to 0.026 ± 0.006 mg/mL for the BP50 digest sample. It can be assumed that the BP30 bar best met the assumed criteria, and is optimal for both sensory quality (receiving an average score of 4.45) and health benefits.

Antioxidant Bioaccessibility of Cooked Gluten-Free Pasta Enriched with Tomato Pomace or Linseed Meal

Gluten-free products lack bioactive compounds, while vegetable wastes from food manufacturing are still rich in nutrients. This study compared the antioxidants of gluten-free pastas enriched with vegetable by-products: the control formulation (66.7% rice and 33.3% fava bean flours) was enriched with 10% or 15% of tomato waste (TO) or defatted linseed cake (LI). Carotenoids, tocols, phenolics, and antioxidant capacity (ABTS and FRAP) were determined in the cooked pasta as well as in the soluble and insoluble fractions after in vitro gastro-intestinal digestion. The cooked enriched pastas showed higher levels of carotenoids (1.36-1.53 vs. 1.02 mg/kg DM), except for the LI-added samples, tocols (8.83-21.70 vs. 7.01 mg/kg DM), free polyphenols (218.1-258.6 vs. 200.9 mg/kg DM), bound polyphenols (132.7-177.6 vs. 101.9 mg/kg DM), and antioxidant capacity. Cooking augmented the carotenoids and free polyphenols in the enriched pastas, tocols in LI pastas and bound flavonoids in TO pastas. After digestion, the recoveries for soluble and insoluble fractions were 53% and 35% for carotenoids, 52% and 43% for tocols, 109% for free phenolic acids, 97% for free flavonoids, 93% for bound phenolic acids, and 100% for bound flavonoids. Bioaccessibility was the highest for free phenolic compounds, whereas carotenoids and tocols were partially available.

Quinoa greens as a novel plant food: a review of its nutritional composition, functional activities, and food applications

Quinoa (Chenopodium quinoa Willd) is widely regarded as a versatile pseudo-cereal native to the Andes Mountains in South America. It has gained global recognition as a superfood due to its rich nutritional profile. While quinoa grains are well-known, there is an undiscovered potential in quinoa greens, such as sprouts, leaves, and microgreens. These verdant parts of quinoa are rich in a diverse array of essential nutrients and bioactive compounds, including proteins, amino acids, bioactive proteins, peptides, polyphenols, and flavonoids. They have powerful antioxidant properties, combat cancer, and help prevent diabetes. Quinoa greens offer comparable or even superior benefits when compared to other sprouts and leafy greens, yet they have not gained widespread recognition. Limited research exists on the nutritional composition and biological activities of quinoa greens, underscoring the necessity for thorough systematic reviews in this field. This review paper aims to highlight the nutritional value, bioactivity, and health potential of quinoa greens, as well as explore their possibilities within the food sector. The goal is to generate interest within the research community and promote further exploration and wider utilization of quinoa greens in diets. This focus may lead to new opportunities for enhancing health and well-being through innovative dietary approaches.

Effects of Artemisia dracunculus powder on dough rheology and quality properties as a novel ingredient in bread formulation

Tarragon has a great potential to be a healthy functional food ingredient thanks to its rich antioxidant, phenolic compounds, and nutrient content. The possibility of enriching bread with tarragon was investigated. For this aim, tarragon powder was used at the rates of 0, 2, 4 and 6% instead of wheat flour. In this study, the effects of substitution on the rheological properties of bread dough and color, total phenolic content, antioxidant activity, texture, sensory, and Fourier transform infrared (FT-IR) analysis of bread samples were performed. The composition of tarragon powder showed significant protein (23.16%), crude fiber (7.4%), antioxidant (48.22 ± 0.11%), and total phenolic content (511.66 ± 1.56 mg GAE/100 g). Bread samples with increased fiber and protein content were obtained by adding tarragon powder to the bread formulation. The major differences in the FT-IR absorbance spectra for the bread samples were not observed. Additionally, tarragon powder significantly increased the antioxidative properties of breads (p < 0.05). Adding up to 4% tarragon powder to the bread formulation increased the sensory scores of the breads.

Innovative high-fiber wheat bread fortified with micronized oat and Plantago ovata husks: Spectroscopic and physicochemical characteristics

Micronized oat husk and Plantago ovata husk were used as dietary fiber sources in wheat bread. The addition of 20% micronized oat husk improved dough yield but resulted in a darker bread crumb, decreased loaf volume, and deteriorated texture. In contrast, 5% P. ovata husk enhanced the springiness and cohesiveness of the crumb, as confirmed by rapid visco-analysis of pasting properties and Fourier-transform infrared spectra. The improvement was ascribed to increased interaction via hydrogen or glycosidic bonds. Bread enriched with 10% micronized oat husk and 5% P. ovata husk contained 9.2 g/100 g FW of fiber (a 5-fold increase), 7.1 g/100 g FW of protein (a decrease of 21%), 40.1 g/100 g FW of carbohydrates (a decrease of 21.6%), and had a calorific value of 212 kcal/100 g FW (a decrease of 22%). In vitro, analysis showed higher starch digestibility for the bread. Furthermore, both P. ovata husk and micronized oat husk improved the antioxidant properties of potentially bioaccessible fractions, particularly the ability to quench hydroxyl radicals, which was 2.7-fold higher in the bread with the highest contribution of micronized oat husk.

The Protein-Rich Powdered Beverages Stabilized with Flax Seeds Gum—Antioxidant and Antiproliferative Properties of the Potentially Bioaccessible Fraction

The functional beverages market is one of the fastest-growing sectors of functional food production. An innovative recipe for powdered fruit and vegetable drinks fortified with lentil proteins (AGF) and stabilized with flax seed gums (FSG) was developed. The study focused on the analysis of potentially bioaccessible fractions from the produced beverages in terms of their antioxidant, antiproliferative activities and physicochemical properties. The contents of bioactive components were tailored by the incorporation of lyophilized fruits and vegetables, the FSG and the AGF. Digestion in vitro effectively released phenolics from all matrices. The highest contents of potentially bioavailable polyphenols were recorded for the AGF based beverages enriched with 5% of FSG and green-leafy vegetables (58 mg/100 mL) and those with lyophilized fruit (54 mg/100 mL). The reducing power of the beverages was mainly affected by the presence of the AGF, while the FSG and lyophilized fruit improved the chelating power. The digests applied in the concentrations mimicking physiological concentrations showed antiproliferative properties against gastric and colon adenocarcinoma—they seemed to be tailored by bioactive peptides and phenolics, respectively. The addition of the FSG improved the stability of the beverages increasing the time required for a reduction of 20% of the initial optical density by 16- and 28-times in the beverages without additives or enriched with vegetables. Both, the AGF and FSG stabilize the beverages after rehydration and are sources of bioaccessible antioxidant and anticancer components, which create their functionality.

Changes in the Polyphenolic Profile and Antioxidant Activity of Wheat Bread after Incorporating Quinoa Flour

Quinoa is a trend and a promising functional food ingredient. Following previous research into the impact of incorporating quinoa flour on the polyphenol content and antioxidant activity of bread, this study aimed to bridge an existing gap about the qualitative and quantitative polyphenolic profiles of such bread. The UPLC-MS/MS analysis showed that quinoa bread, made with 25% quinoa flour of a black variety, presented more compounds than refined-wheat bread, and levels were remarkably higher in many cases. Consequently, the quinoa bread presented clearly improved polyphenolic content than the wheat bread (12.8-fold higher considering the sum of extractable and hydrolyzable polyphenols), as supported by greater antioxidant activity (around 3-fold). The predominant compounds in the extractable fraction of quinoa bread were p-hydroxybenzoic acid and quercetin (50- and 64-fold higher than in wheat bread, respectively) and rutin (not detected in wheat bread), while ferulic and sinapic acids were the most abundant compounds in the hydrolyzable fraction (7.6- and 13-fold higher than in wheat bread, respectively). The bread-making impact was estimated, and a different behavior for phenolic acids and flavonoids was observed. Extractable phenolic acids were the compounds that decreased the most; only 2 of 12 compounds were enhanced (p-hydroxybenozoic and rosmarinic acid with increments of 64% and 435%, respectively). Flavonoids were generally less affected, and their concentrations considerably rose after the bread-making process (7 of the 13 compounds were enhanced in the extractable fraction) with especially noticeably increases in some cases; e.g., apigenin (876%), kaempferol (1304%), luteolin (580%) and quercetin (4762%). Increments in some extractable flavonoids might be explained as a consequence of the release of the corresponding hydrolyzable forms. The present study provides new information on the suitability of quinoa-containing bread as a suitable vehicle to enhance polyphenols intake and, hence, the antioxidant activity in daily diets.

Effect of yerba mate (Ilex paraguariensis) leaves on dough properties, antioxidant activity, and bread quality using whole wheat flour

This study investigated the effects of different yerba mate (YM) proportions (1.5, 2.5, and 4.5 g YM/100 g whole wheat flour (WWF) and particle sizes (245, 415.5, and 623.9 µm) on dough rheological properties, antioxidant activity, and bread characteristics. The addition of YM leaves led to a possible interaction between its phenolic compounds and the gluten network within the dough, without negative effects on dough formation. However, the larger YM particle size (623.9 µm) caused a weakening of the protein network, resulting in lower quality product compared to the other samples. Improved bread quality was found when the YM leaves were added at 2.5 g YM/100 g WWF. The total amount of phenolic compounds and the antioxidant activity increased as the proportion of YM increased in both flour and bread. Moreover, the phenolic compounds in 2.5 g YM/100 g WWF breads were stable during baking, showing no significant losses in the amount of phenolic compounds and antioxidant activity. These results suggest the YM can be successfully incorporated into baked product, improving its functional characteristics. PRACTICAL APPLICATION: This study evaluates the technological quality of bakery product made by incorporating yerba mate leaves in whole wheat flour. The results will contribute to the production of a bread with greater functional properties due to the presence of polyphenols and phytochemicals.

The Influence of Hypericum perforatum L. Addition to Wheat Cookies on Their Antioxidant, Anti-Metabolic Syndrome, and Antimicrobial Properties

The aim of this study was to characterize wheat cookies enriched with 0.5% and 1.0% of Hypericum perforatum L. (St. John's wort, SJW) and determine their pro-health properties in vitro after hydrolysis in simulated gastrointestinal conditions. The results indicated that 1.0 SJW was characterized by the highest content of polyphenols, flavonoids, and phenolic acids (2.32 mg mL-1, 4.93 µg mL-1, and 12.35 µg mL-1, respectively). The enriching cookies had no effect on water absorption capacity (WAC) and oil absorption capacity (OAC). After in vitro hydrolysis, the highest peptide content was noted in 1.0 SJW (0.52 mg mL-1), and the bioactive compounds were characterized by high potential bioaccessibility (PAC), but poor bioavailability (PAV). The addition of SJW increased the ACE, α-amylase, and LOX inhibitory effect, but reduced the inhibition of pancreatic lipase. The highest antioxidant activity was noted for 1.0 SJW. The results showed that only 0.5 SJW and 1.0 SJW had slight antimicrobial activity against E. coli ATCC 25922 and B. cereus ATCC 14579 with MIC = 12.5 mg mL-1. Fractions with molecular mass <3.0 kDa were characterized with the highest p-coumaric acid content. The results show that SJW cookies had a higher content of bioactive compounds and more potent anti-metabolic syndrome effects.

Potentially Bioaccessible Phenolic and Antioxidant Potential of Fresh and Stored Lentil Sprouts-Effect of Lactobacillus plantarum 299v Enrichment

The phenolic and antioxidant potential of potentially bioaccessible fractions of lentil sprouts was studied. Sprouts were cocultivated with a probiotic to obtain a new functional product and further stored in cool conditions. The fraction obtained after buffer extraction and gastric digestion had higher content of phenolics compared to the control (by 20% and 46%, respectively); however, a 9% decrease was observed in samples obtained after gastrointestinal digestion. After gastrointestinal digestion, the highest content of phenolics (278 µg/g d.w.) was determined in the fresh control sprouts. Compounds neutralizing ABTS and hydroxyl radicals, chelating metal ions, and exhibiting strong reducing power were effectively released after gastrointestinal digestion (e.g., the values of the gastrointestinal digestibility index for chelating power and ability to quench hydroxyl radicals significantly exceeded 1 in all studied samples). It was proved that the enrichment of sprouts with a probiotic and further storage significantly improved the antioxidant potential; compared to the fresh control sprouts, an increase by 45% and 10% was determined after the gastric and gastrointestinal digestion, respectively. Lentil sprouts enriched with L. plantarum 299v may be a new functional product characterized by the high antioxidant capacity of the potentially bioaccessible fraction.

Wheat Bread Fortification by Grape Pomace Powder: Nutritional, Technological, Antioxidant, and Sensory Properties

Grape pomace powder (GPP), a by-product from the winemaking process, was used to substitute flour for wheat bread fortification within 0, 5, and 10 g/100 g. Rheological properties of control and fortified doughs, along with physicochemical and nutritional characteristics, antioxidant activity, and the sensory analysis of the obtained bread were considered. The GPP addition influenced the doughs' rheological properties by generating more tenacious and less extensible products. Concerning bread, pH values and volume of fortified products decreased as the GPP inclusion level increased in the recipe. Total phenolic compounds and the antioxidant capacity of bread samples, evaluated by FRAP (ferric reducing ability of plasma) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) assays, increased with GPP addition. Moreover, the GPP inclusion level raised the total dietary fiber content of bread. Regarding sensory evaluation, GPP fortification had a major impact on the acidity, the global flavor, the astringency, and the wine smell of bread samples without affecting the overall bread acceptability. The current results suggest that GPP could be an attractive ingredient used to obtain fortified bread, as it is a source of fiber and polyphenols with potentially positive effects on human health.

Characterization and Bio-Accessibility Evaluation of Olive Leaf Extract-Enriched "Taralli"

Olive leaves are rich in many compounds precious for human health. Due to this property, the current study was aimed to valorize the extract from this by-product in a cereal-based food, very popular all around the world, the "taralli". To this aim, ultrasound-assisted extraction was applied to dried olive leaves to obtain the extract, used as "taralli" ingredient, instead of white wine. The "taralli" with and without extract was subjected to in vitro digestion to assess the quantity of polyphenolic compounds released in the gastrointestinal tract to become available for absorption. Total content of phenols and flavonoids, as well as the antioxidant capacity, was measured on both cooked and uncooked samples, before and after digestion. In addition, High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) of the three most abundant polyphenols present in olive leaf extracts, such as oleuropein, hydroxytyrosol, and verbascoside, was carried out at the three stages of the digestion process. The results showed that the substitution of white wine with olive leaf extract increased the total content of polyphenols and flavonoids and the antioxidant capacity. Bio-accessibility of the main phenolic compounds demonstrated that oleuropein resisted slightly after gastric digestion but was almost completely degraded in the intestinal phase, while hydroxytyrosol and verbascoside were not resistant to the digestion process from the gastric phase.

Yellow-coated quinoa (Chenopodium quinoa Willd) - physicochemical, nutritional, and antioxidant properties

BACKGROUND

Quinoa seeds are an excellent source of nutrients and phytochemical compounds with well documented activity; however, different cultivars are usually characterized by different physical properties and chemical composition. This study presented the physical properties, nutrient content, and antioxidant capacities of 25 cultivars of yellow-coated quinoa.

RESULTS

The results demonstrated that quinoa seeds may be an excellent source of dietary fiber (up to 198 g kg^-1 d.m. - Baer cultivar), with a 1:2 ratio of the soluble to insoluble fraction. Digestible carbohydrates were present at the highest level in the Puno cultivar (640 g kg^-1 ). The highest content of proteins was determined in the Colorado 407D and Faro cultivars (c.a. 16%). The average content of albumin and globulins in the seeds was 29.2 and 65.6 g kg^-1 , respectively. The quinoa seeds were characterized by low activity of protease inhibitors. The lowest inhibition of trypsin was determined for the UDEC-3, Faro Orange, and Titicaca cultivars, and the highest value was exhibited by the Titicaca White and UDEC-5 cultivars. Phenolics in the tested cultivars ranged from 7.1 g kg^-1 (UDEC-3) to 10.6 g kg^-1 (Temuko). The best antiradical properties were determined for Temuco and Rainbow (2.05 g TE kg^-1 and 1.85 g TE kg^-1 , respectively), while the Baer and Temuco cultivars were characterized by the highest reducing power (2.28 g TE kg^-1 and 2.17 g TE kg^-1 , respectively).

CONCLUSION

This study has shown that quinoa cultivated in European countries is a good source of nutrients, dietary fiber, and antioxidants; however, its composition varies significantly. © 2019 Society of Chemical Industry.

Drying Kinetics, Grinding Characteristics, and Physicochemical Properties of Broccoli Sprouts

In this study, we studied the drying process, grinding characteristics and physicochemical characteristics of broccoli sprouts (BS). The seeds of broccoli were germinated at 20 °C for 3 and 6 days. Then, the seeds were air- and freeze-dried, and the Page model was used for prediction of drying kinetics of broccoli sprouts. It was observed that the drying time of BS decreased about twofold as the air-drying temperature increased from 40 to 80 °C. An increasing the air-drying temperature from 40 to 80 °C decreased the drying time by approximately twofold. Freeze-drying of sprouts took the longest drying time. Germination of seeds significantly decreased the value of grinding energy requirements, and the ground sprouts exhibited a different grinding pattern in comparison to ground non-germinated seeds. In terms of color parameters, the highest lightness and yellowness were found for freeze-dried sprouts. Redness and yellowness of sprouts increased with an increase in the air-drying temperature. The lowest total color difference was obtained for the freeze-dried sprouts. Higher drying temperature resulted in lower total phenolics content (TPC) and decreased antioxidant activity (AA). The highest TPC and AA were observed in air-dried sprouts (40 °C) and freeze-dried sprouts after 6 days of germination.

Different Temperature Treatments of Millet Grains Affect the Biological Activity of Protein Hydrolyzates and Peptide Fractions

The objective of this study was to analyze millet protein hydrolyzates and peptide fractions with molecular mass under 3.0 kDa obtained from grains treated with different temperature values as inhibitors of angiotensin-converting enzyme (ACE), α-amylase, and α-glucosidase activity. The protein fractions were hydrolyzed in vitro in gastrointestinal conditions and the highest degree of hydrolysis was noted for globulin 7S obtained from control grains (98.33%). All samples were characterized by a high peptide bioaccessibility index, which was 23.89 for peptides obtained from globulin 11S after treatment with 100 °C. The highest peptide bioavailability index was noted for peptides obtained from globulin 11S after the treatment with 65 °C (2.12). The highest potential metabolic syndrome inhibitory effect was determined for peptide fractions obtained from the prolamin control (IC50 for ACE and α-amylase was 0.42 and 0.11 mg/mL, respectively) and after the 100 °C treatment (IC50 for ACE and α-glucosidase was 0.33 and 0.12 mg/mL, respectively) and from globulin 11S after the 65 °C treatment (IC50 0.38 and 0.05 for ACE and α-glucosidase, respectively). The effect of these samples on endothelial cell HECa10 was determined. The sequences of potential inhibitory peptides were identified as GEHGGAGMGGGQFQPV, EQGFLPGPEESGR, RLARAGLAQ, YGNPVGGVGH, and GNPVGGVGHGTTGT.

Utilization of Kañawa (Chenopodium pallidicaule Aellen) Flour in Pasta Making

Kañawa (Chenopodium pallidicaule Aellen) is an Andean crop harvested in Bolivia and Perú. Because of the characteristics and properties of kañawa seed, its flour can be used to replace partially wheat flour in pasta to increase its nutritional value. The objective of this study was to investigate the production of fiber- and protein-enriched pasta made with wheat and kañawa blends. The effect of the substitution level of wheat by kañawa flour on pasta quality was evaluated taking into account the influence of kañawa composition on starch behavior and gluten network formation. Proximal composition, thermal behavior, and pasting properties of kañawa and wheat flours were determined. Pasta was made from wheat flour (control) replacing 10, 20, and 30% of wheat by kañawa flour from L1 and L2 ecotypes. Water absorption and cooking loss were increased showing the deleterious effect of kañawa flour on pasta quality, but the L1 ecotype showed better performance in cooking properties. Kañawa pasta firmness and chewiness decreased with the kañawa content increase; however, the L1 ecotype did not modify the firmness when 10 and 20% were included in pasta. Both kañawa flours improved the nutritional quality of pasta, increasing the dietary fiber content and protein quality.

Evaluation of the impact of different drying methods on the phenolic compounds, antioxidant activity, and in vitro digestion of green coffee beans

We investigated the effects of different drying methods (room temperature drying, heat pump drying, freeze drying, microwave vacuum drying [MVD], and combined microwave power vacuum drying) on the active ingredients of green coffee beans. We specifically focused on eleven phenolic acids, total phenolic content (TPC), total flavonoid content, antioxidant activity, polyphenol oxidase (PPO), the inhibition of linoleic acid peroxidation (LPO), and enzyme activity, and the bio-accessibility in vitro and bioavailability of phenolics and antioxidant activities were also evaluated. MVD-treated beans had the lowest PPO activity and the highest contents of 5-caffeoylquinic acid (1.39 g/100 g DW), 3-feruloylquinic acid (0.25 g/100 g DW), 4-feruloylquinic acid (0.25 g/100 g DW), 5-feruloylquinic acid (1.52 g/100 g DW), and TPC (5.98 g GAE/100 g DW), and the highest antioxidant activity. MVD was the least time-consuming (0.63 hr/kg) and energy-consuming (1.88 kwh/kg) method. Moreover, the strongest inhibition of LPO and α-glucosidase was observed in MVD-treated beans. Thus, MVD is suggested to be the most suitable drying technique for the preservation of phenolic compounds and bioactivities of green coffee beans.

Influence of Drying Temperature on Phenolic Acids Composition and Antioxidant Activity of Sprouts and Leaves of White and Red Quinoa

The aim of this study was to evaluate the influence of drying temperature on the phenolic acids profile and antioxidant activity of sprouts and leaves red and white Chenopodium quinoa (RQ and WQ, respectively). Four-day sprouts and leaves dried at 30, 45, and 60°C were tested. All sprouts contained significant amounts of phenolic compounds; however, higher content was determined in the RQ sprouts. Phenolic compounds from WQ sprouts seem to be thermostable in the studied temperature range, whereas total phenolics content in RQ sprouts decreased significantly after drying in the 60°C. Content of vanillic and p-coumaric acids did not differ significantly between sprouts dried at the same conditions; however, their level decreased in the high temperature. Irrespective of the drying temperature, higher activity against ABTS free radicals and reducing power was observed in the case of RQ sprouts extracts. Sprouts dried at 30°C had a higher ability to scavenge hydroxyl radicals. RQ sprouts were characterized by about two times higher antioxidant activity regardless of the method used. No significant differences between total phenolics (TPC) and flavonoids content in RQ and LQ leaves were found. In the both cases, decrease of TPC was observed after drying in the highest temperature. The leaves do not differ too much in terms of the phenolic acids profile, whereas the differentiating factor is thermal processing. Leaves of both quinoa contained thermostable compounds able to scavenge hydroxyl radicals. Reducing power and ability to scavenge OH radicals were correlated with all components of quinoa sprouts which suggest synergism between them and does not indicate the key role of a particular compound in creating antioxidant capacity. Germination and subsequent oven-drying at 30°C of quinoa seeds significantly increased the antioxidant properties compared with raw seeds. Also, in the case of leaves, the best results were obtained after drying at 30°C.

Hydrogen Peroxide Treatment and the Phenylpropanoid Pathway Precursors Feeding Improve Phenolics and Antioxidant Capacity of Quinoa Sprouts via an Induction of L-Tyrosine and L-Phenylalanine Ammonia-Lyases Activities

Hydrogen peroxide treatment and the phenylpropanoid pathway precursors feeding affected the antioxidant capacity of quinoa sprouts. Compared to the control, total phenolics content was significantly increased by treatment of control sprouts with 50 mM and 200 mM H2O2—an elevation of about 24% and 28%, respectively. The highest increase of flavonoids content was found for the sprouts treated with 200 mM H2O2obtained from seeds fed with shikimic acid. All the studied modifications increased the antioxidant potential of sprouts (at least by 50% compared to control). The highest reducing power was found for the sprouts treated with 200 mM H2O2obtained by phenylalanine feeding (5.03 mg TE/g DW) and those obtained from the seeds fed with tyrosine (5.26 mg TE/g DW). The activities of L-tyrosine (TAL) and L-phenylalanine (PAL) ammonia-lyases were strongly affected by germination time as well as the applied modification of sprouting. On the 3rd day the highest PAL activity was determined for both untreated and induced with 50 mM H2O2sprouts obtained by phenylalanine feeding. H2O2induced TAL activity; the highest TAL activity was determined for 3-day-old sprouts induced with 200 mM H2O2obtained from seeds fed with phenylalanine.