Phenolic Compounds Research Articles

Development of a Bioprocess to Improve the Phenolic Compounds Content and Antioxidant Capacity in Blue Corn Grains

Development of a Bioprocess to Improve the Phenolic Compounds Content and Antioxidant Capacity in Blue Corn Grains

Efficacy of Bacillus and Trichoderma on growth and anthracnose resistance in scallion

Biotic elicitors, including Trichoderma and Bacillus can improve plant growth and disease resistance. Current research evaluated the efficacy of 14 Bacillus subtilis strains, Trichoderma viride, Trichoderma harzianum, Trichoderma sp. on enhancing growth and managing anthracnose in scallion. The inhibition efficiency of Bacillus and Trichoderma on Colletotrichum growth was assessed in vitro. Besides, effective biotic treatments against anthracnose were evaluated at net house conditions. Then, defence mechanisms including endogenous SA accumulation, production of phenolic compounds, catalase, peroxidase, phenylalanine ammonia-lyase and b-1,3-glucanase were revealed. The results showed that four biotic elicitors, including B. subtilis strains CaSUT008-2, D604, SUNB1 and T. harzianum showed high antagonistic activity against in vitro growth of Colletotrichum colonies at 41-77 %. At 28 days after planting, scallion plants treated with B. subtilis strain CaSUT008-2 and SUNB1 gained stem length at 15.35-15.79 cm. These four biotic treatments had low disease severity in net-house conditions at 25.00-50.00 %. On mechanisms of anthracnose resistance, at 24 hours after inoculation (HAI), scallion plants treated with T. harzianum and B. subtilis strain CaSUT008-2 showed high content of salicylic acid at 2.17-2.20 µg/g fresh weight. At 48 HAI, scallion plants induced by B. subtilis strain SUNB1 increased phenolic compounds at 42.65 µg gallic acid/mg dry mass. Moreover, four biotic elicitors enhanced activities of catalase, peroxidase, phenylalanine ammonia-lyase and b-1,3-glucanase in treated scallion plants. This study suggests that B. subtilis strain CaSUT008-2 and SUNB1, T. harzianum stimulated growth, helped scallion plants against anthracnose disease. The combined Trichoderma-bacteria bio-inoculants may be a good strategy to develop biocontrol agent and plant growth promoter within green and sustainable production of scallion.

Quality Response of Two Mini Chinese Cabbage Cultivars to Different Calcium Levels

This study investigated the effects of different calcium levels on the nutritional quality and stress resistance of mini Chinese cabbage, focusing on the ‘QYH’ calcium-sensitive cultivar and the ‘HN’ calcium-tolerant cultivar. Plants were treated with five calcium levels (0, 2, 4, 6, and 8 mmol/L) to analyze the incidence of tip-burn, tissue calcium content, mineral accumulation, amino acid composition, and phenolic and flavonoid compound contents. The results showed that appropriate calcium levels significantly reduced tip-burn incidence. Specifically, ‘QYH’ exhibited no tip-burn symptoms at 6 mmol/L calcium, while ‘HN’ was tip-burn free at 4 mmol/L. Appropriate calcium levels also significantly increased the contents of soluble sugars, proteins, and ascorbic acid while reducing nitrate levels in both cultivars. For example, the soluble sugar content in ‘QYH’ increased by 119.05% under the 6 mmol/L calcium treatment. Similarly, ‘HN’ showed significant increases in soluble sugars, proteins, and ascorbic acid at 4 mmol/L. Amino acid and phenolic compound levels peaked at 6 mmol/L calcium in ‘QYH’, with rutin content in ‘QYH’ increasing by 181.58%. In ‘HN’ these compounds peaked at 4 mmol/L. Additionally, high calcium levels did not antagonize key minerals but reduced manganese accumulation. These findings highlight calcium’s critical role in enhancing the nutritional quality of mini Chinese cabbage and provide a scientific basis for optimizing calcium fertilizer application for both ‘QYH’ and ‘HN’ cultivars.

Comparison of silver and gold nanoparticles green synthesis by Artemisia annua hairy root extracts.

The green synthesis of metal nanoparticles has garnered significant attention due to its simplicity, cost-effectiveness, and environmental sustainability. Gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) are widely employed across various industries, agriculture, and medicine owing to their unique physicochemical properties. This study explores the feasibility of synthesizing metal nanoparticles through green methods using ethanolic (70%) extracts from Artemisia annua hairy roots. These extracts were found to contain reducing agents, primarily phenolic compounds, as identified by HPLC and MALDI-MS analyses. The phenolic compounds included hydroxybenzoic acids (e.g., p-coumaric and gallic acids) and hydroxycinnamic acids (e.g., caffeic acid and its derivatives such as chlorogenic, dicaffeoylquinic, and rosmarinic acids). The synthesis and structural characteristics of AuNPs and AgNPs were systematically compared. AgNPs formed a stable colloidal solution over extended periods, while AuNPs exhibited instability due to significant nanoparticle aggregation and precipitation. Furthermore, the photocatalytic activities of these nanoparticles in the degradation of methylene blue were evaluated. AuNPs demonstrated substantial photocatalytic activity, whereas AgNPs exhibited negligible catalytic effects. This study highlights the potential and limitations of A. annua hairy root extracts in the biosynthesis of AuNPs and AgNPs, providing insights into their structural and functional differences.

Exploring Antioxidant Properties of Standardized Extracts from Medicinal Plants Approved by the Thai FDA for Dietary Supplementation.

There is a growing interest in plant-derived antioxidants as functional food ingredients, given their potential to address oxidative stress-related diseases, notably neurodegenerative disorders. This study aims to investigate the antioxidant properties of medicinal plants that have been approved by the Thai FDA for dietary supplementation, with the goal of further utilizing them as food-functional ingredients to prevent neurodegenerative conditions. A systematic review-based methodology was employed on a list of 211 medicinal plants, and 21 medicinal plants were chosen based on their documented antioxidant activity and acetylcholinesterase (AChE) inhibitory capacity. The 21 commercially available standardized extracts were subjected to evaluation for their phenolic and flavonoid content, as well as their antioxidant activities utilizing metal-chelating activity, DPPH, ABTS free radical scavenging, ferric-reducing antioxidant power (FRAP), and superoxide anion scavenging techniques. Among the 21, six extracts-Bacopa monnieri, Camellia sinensis, Coffea arabica, Curcuma longa, Tagetes erecta, and Terminalia chebula-emerged as the most promising. These extracts exhibited elevated levels of phenolic (up to 1378.19 mg gallic acid equivalents per gram) and flavonoids, with Coffea arabica and Curcuma longa showing the strongest antioxidant and free radical scavenging activities, indicating their potential for use in functional foods aimed at delaying neurodegenerative diseases. Due to their high levels of phenolic and flavonoid compounds, along with strong metal-chelating abilities and significant free radical scavenging activities, these standardized extracts show potential for functional food applications that may help delay the onset of neurodegenerative diseases.

Exploring tannin structures to enhance enzymatic polymerization.

The enzymatic polymerization of biomass-derived polyphenols presents a sustainable approach to producing advanced materials. However, the structural diversity and incomplete characterization of tannins pose challenges to optimizing the process. This study investigates how tannin composition and the presence of phenolic and non-phenolic compounds in aqueous Pinus radiata bark extracts influence laccase-catalyzed polymerization and the resulting material's thermal and structural properties. The extracts were characterized using proximate and ultimate analysis, Py-GC/MS, FT-IR, TGA, and phenol content analysis before polymerization with Myceliophthora thermophila laccase (MtL). Structural and thermal analysis of the polymers revealed significant transformations driven by enzymatic oxidation. Tannin extracts rich in resorcinol and low in carbohydrates and less polar compounds produced highly cross-linked polymers with exceptional thermal stability, retaining 86% residual mass at 550°C. These findings demonstrate that tannin composition plays a key role in polymerization efficiency and material performance. The resulting thermally stable polymers offer potential applications in flame retardancy and sustainable material development, providing a promising pathway for biomass valorization.

Invitro Evaluation of the Anti-Inflammatory Activity of Phloroglucinol and Alpha-lipoic acid

It was decided to test the anti-inflammatory activity of phloroglucinol and alpha-lipoic acid combined in order to evaluate the possibility of a synergistic effect in the battle against inflammation. Both the antioxidant alpha-lipoic acid and the naturally occurring phenolic compound phloroglucinol were investigated by researchers in order to ascertain whether or not they were capable of modulating inflammatory pathways and pathways in vitro. The effects of the combination on numerous inflammatory mediators, including cytokines (TNF-α, IL-1β, and IL-6), prostaglandin E2 (PGE2), and nitric oxide (NO) generation, were assessed by employing human peripheral blood mononuclear cells (PBMCs) that were cultivated. The results demonstrated that these pro-inflammatory markers were greatly reduced following the combination treatment, which may indicate that the combination treatment had a synergistic effect on reducing inflammation. Furthermore, the combination had a considerable impact on inhibiting the activation of nuclear factor-kappa B (NF-κB), which is an essential regulator of inflammation. These findings imply that the combination of phloroglucinol and alpha-lipoic acid could be a feasible therapy method for inflammatory disorders; nevertheless, additional in vivo research are required to establish the efficacy and safety of the combination.

Metabolic Response Induced by Methyl Jasmonate and Benzothiadiazole in Vitis vinifera cv. Monastrell Seedlings

This study evaluates the effects of the elicitors methyl jasmonate (MeJ) and benzothiadiazole (BTH) on the synthesis of phenolic compounds in Vitis vinifera cv. Monastrell seedlings over 72 h. Results show that both elicitors induce the accumulation of stilbenes and phenolic acids, essential compounds in plant defence against pathogens. Specifically, MeJ significantly increased the levels of astringin, T-resveratrol, and miyabenol C, known for their antifungal properties, indicating a rapid and effective activation of plant defences. Discriminant analysis revealed that MeJ and BTH markedly altered the phenolic profile, highlighting their role in modulating defence responses. However, their combined application exhibited antagonistic effects on some compounds, suggesting an adaptive metabolic response. The defence response was transient, with peak concentrations observed within the first 24 h, followed by down-regulation, optimising the plant’s energy resources. These findings suggest that MeJ and BTH can enhance the resistance of the Monastrell variety, potentially reducing pesticide use in sustainable viticulture. Further studies are needed to assess their long-term effects under field conditions, considering environmental variables and optimal application rates.

Extract optimization of Ulva lactuca L. and biological activities of optimized extracts

BackgroundAlgae are microscopic or macroscopic organisms that can photosynthesize and are found in both freshwater and saltwater ecosystems and are considered one of the cornerstones of life. In our study, the biological activities of extracts produced under the extract conditions that provided the highest biological activity of Ulva lactuca L. were determined.MethodsTwo different methods, Response Surface Method (RSM) and Artificial Neural Network-Genetic Algorithm (ANN-GA) integration were used for optimization. In this context, the optimum extract conditions were determined as 54.940 ˚C temperature, 6.513 h, 42.109 ethanol/water ratio according to the RSM method and 56.286 ˚C temperature, 7.2793 h, 36.8625 ethanol/water ratio according to ANN-GA. The antioxidant activities of the optimized extracts were evaluated by Rel Assay kits, DPPH and FRAP methods. Anticholinesterase activities were determined by testing against acetylcholinesterase and butyrylcholinesterase enzymes. In addition, antiproliferative effects were examined in A549 lung cancer cell line and phenolic compound contents were analyzed by LC-MS/MS.ResultsAs a result of the analyzes, it was seen that the extract obtained from the conditions recommended by ANN-GA exhibited higher activities. Optimized extracts of U. lactuca were found to have potential in terms of antioxidant activities. The highest total antioxidant value was determined as 6.272 ± 0.024 mmol/L. In addition, it was determined that extracts of U. lactuca produced under optimum conditions showed strong cytotoxic effects against A549 lung cancer cell line. In addition, gallic acid, 4-hydroxybenzoic acid, caffeic acid, vanillic acid, syringic acid, quercetin and kaempferol were found in the extracts of the algae produced under optimum conditions. The highest detected compound was caffeic acid. In addition to all these properties, it was seen that U. lactuca has anticholinesterase potential in our study.ConclusionIn conclusion, optimized extracts of U. lactuca attract attention with their antioxidant and cytotoxic activities as well as anticholinesterase potential and can be considered as a potential source for cancer treatment and management of neurological diseases.

The role of various dairy food matrices on the amount and in vitro bioaccessibility of phenolics in elderberries

PurposeElderberry (Sambucus nigra) fruits are rich in bioactive components, specifically in anthocyanins. In this study, freeze-dried and powdered elderberry fruits were added to milk, yoghurt and kefir samples at ratios of 5, 10 and 15% (w/w) to fortify these dairy products at home scale, and final products were monitored to understand the behaviour of bioactive compounds.Design/methodology/approachThe action of bioactive compounds was examined before and after in vitro gastrointestinal digestion by the analysis of total anthocyanin content, total phenolic content and antioxidant activity assays as well as the HPLC-PDA system on the first day of preparation. Moreover, the effect of three days of storage on individual phenolic compounds was evaluated.FindingsKefir samples exhibited the highest total anthocyanin content levels among prepared products (255±4-702±65 µmol cyanidin-3-glucoside eq/100 g), which is followed by yoghurt samples. Individual phenolics in samples prepared at the same concentrations behaved almost similarly with each other during gastric digestion phases (p > 0.05), whereas intestinal digestion phases caused significant differences, and phenolics in yoghurt samples exhibited higher values than others (p < 0.05). The stability of bioactive compounds in samples tended to decrease during storage; however, as observed during gastrointestinal digestion, yoghurt and kefir samples provided better matrices than milk to maintain the presence of bioactive compounds (p < 0.05).Originality/valuePrevious studies have indicated that elderberry fruits contain high levels of bioactive compounds, and these fruits have been used to fortify different food matrices. However, this research paper investigates the interaction between three selected dairy products and elderberry powder with each other for the first time.

In silico approach of gambier extract for Diabetes Mellitus and multivariate optimization of ultrasound-assisted extraction rich polyphenol using full factorial design

The gambier leaf from Uncaria gambir (W.Hunter) Roxb. is one of the promising natural agents as an antidiabetic candidate. Through an in silico approach, the study delves into the mechanisms of the extract's potential compounds, aiming to comprehend the molecular mechanisms underlying its antidiabetic activity. Additionally, an investigation was conducted to determine the most advantageous outcome of gambier leaf extract and the characteristics of the ideal extract. The extraction method used in the study was ultrasound-assisted extraction (UAE). Data analysis was done using a full factorial design 23 modeling approach. The extraction process involved three key factors: time, temperature, and material-solvent ratio. The observed responses included yield, total flavonoid content (TFC), and antioxidant activity (IC50). Optimal results for the gambier leaf extract were achieved with a 30-minute extraction duration at 50°C using a material-solvent ratio of 1:10, which resulted in an extract yield value of 11.87%; total flavonoid content of 467.51 mgCE/g and antioxidant activity value (IC50) of 66.01 µg/mL with a desirability value of 0.998. The optimal gambier leaf extract characteristics are a moisture content of 0.13% and a drying shrinkage of 0.15. The optimal extract has been demonstrated to contain phenolic compounds, flavonoids, and tannins. The validation results for the optimal extract condition obtained are 95% PI low and 95% PI high. Network pharmacology identified five compounds and three target proteins associated with gambier leaf in treating type 2 diabetes mellitus. Molecular docking analysis indicated that the interactions between SRC receptor and nicotiflorin, AKT1, and nicotiflorin, as well as TNF and procyanidin B2, have biological activity in treatment type 2 diabetes mellitus.

Antioxidant Activity and Phenolic Compound of Rosemary Under Artificial LED Lights

Rosemary (Salvia rosmarinus (L.)) is an herb associated with various pharmacological benefits and exhibits antioxidant effects contributing to improved health. This study aimed to investigate the impact of different LED light conditions on the biological activity of rosemary, with a focus on enhancing its functional properties for agricultural applications. The aerial parts of rosemary grown under red light exhibited the highest growth rate. Additionally, the highest 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities (87.72 ± 0.60% and 17.16 ± 0.65%, respectively) were detected in the red light-treated group rather than in the other treatment groups. Comparably, red light treatment induced the highest total phenolic and total flavonoid contents, measuring 126.72 ± 1.47 mg∙GAE/g and 21.02 ± 1.61 mg∙QE/g, respectively, in rosemary. High-performance liquid chromatography revealed that rosmarinic acid was the predominant phenolic compound in the aerial parts of rosemary grown under red light. These findings suggest that optimizing light conditions can be an effective strategy for improving the functional properties of rosemary, providing insights into its potential application in smart farming and sustainable agricultural practices.

Impact of High-Pressure Processing on Phenolic Compound Accumulation and Expression of Key Biosynthetic Genes in Harvested Strawberries.

Phytochemical accumulation plays a vital role in plant defense. This study examines the effect of high-pressure (HP) treatment on phenolic biosynthesis and gene expression in harvested strawberries, evaluating HP as a potential enhancer of phenolic biosynthesis through environmental stress responses. Strawberries were subjected to HP treatment at pressures ranging from 10 to 40MPa in two or three cycles. This treatment led to significant increases in total phenolic content, up to 1.59 times higher than untreated controls. Gene expression analysis showed upregulation of key biosynthetic genes-phenylalanine ammonia-lyase, chalcone synthase, and UDP-glucose flavonoid 3-O-glucosyl transferase-with peak expression observed after three cycles of treatment at 40MPa. HP treatment effectively enhances phenolic compound synthesis by activating biosynthetic gene expression pathways. This method presents a practical, non-genetic strategy for improving the nutritional profiles of fruits.

Evaluation of the anti-oxidant and anti-obesity effects of ethanolic extract of Ficus auriculata Lour. fruit

Ficus auriculata (F. auriculata), a deciduous tree in the Moraceae family, is a globally significant crop. Because of its abundance of phytochemicals and antioxidants, which are essential to human health, the fig tree is revered as a holy tree. The goal of this study was to determine if the ethanolic extract of F. auriculata fruit has any anti-oxidant or anti obesity effects, both in vitro and in vivo. The DPPH free radical technique for the quantitative determination of free radical scavenging activity and the inhibitory action against pancreatic lipase was measured using p-nitrophenyl butyrate (p-NPB) as a substrate. Blood serum was collected for serum lipid profile determination, histopathological analysis using hematoxylin and eosin stain, and results were viewed using a microscope at x400 magnification. From the results obtained, F. auriculata fruit had a large number of phenolic compounds and possible antioxidant components. The IC50 value of the sample was found to be 49.99 µg/mL. The extract exhibited the highest lipase inhibitory action, with an IC50 value of 45.61 µg/mL. At a dosage of 300 mg/kg, the extract reduced serum lipid profile and body weight in a manner similar to that of the standard drug orlistat and exhibited a reduction in the crown-like structure (CLS/mm3) to 4 CLS/mm3, while the control group had 34 CLS/mm3. Thus, the anti-obesity properties of F. auriculata fruit were confirmed using an HCD-induced obesity rat model. It reduced sugar levels, improved lipid profiles, reduced hepatic steatosis, slowed weight gain, and altered the histological marker of local inflammation.

Optimization of Microwave-Assisted Extraction of Phenolic Compounds from Opuntia ficus-indica Cladodes

Background: Opuntia ficus-indica (OFI) cladodes are valuable and underestimated by-products that provide significant amounts of biologically active compounds. In this paper, microwave-assisted extraction (MAE) was performed for the recovery of phenolic compounds from OFI cladodes using two approaches: response surface methodology (RSM) and artificial neural network–genetic algorithm (ANN-GA), which were then compared following statistical indicators. Materials and Methods: Four independent factors were employed in the optimization process (solvent concentration, microwave power, irradiation time, and solid-to-liquid ratio) by selecting the total phenolic content (TPC), estimated by the Folin–Ciocalteu method, as a response. The optimized extract was tested for antioxidant capacity using the Folin–Ciocalteu reagent, Trolox Equivalent Antioxidant Capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays and for antimicrobial activity against 16 pathogenic strains using the agar well diffusion method. Results: The maximum TPC values predicted with maximizing desirability function for RSM were 2177.01 mg GAE/100 g DW and 1827.38 mg GAE/100 g DW for the ANN. Both models presented certain advantages and could be considered reliable tools for predictability and accuracy purposes. Using these conditions, the extract presented high antioxidant capacity for FCR assay (13.43 ± 0.62 mg GAE/g DW), TEAC (10.18 ± 0.47 µmol TE/g DW), and ORAC (205.47 ± 19.23 µmol TE/g DW). The antimicrobial activity of the optimized extract was pronounced only with respect to S. aureus alimentarius, Streptococcus, E. coli, P. aeruginosa, and A. flavus. Conclusions: This study underlines the high effectiveness of the optimization approaches in providing a maximum recovery of bioactive compounds from OFI cladodes to formulate food and pharmaceutical products with functional qualities.

Copper Sulfate Elicitation Effect on Biomass Production, Phenolic Compounds Accumulation, and Antioxidant Activity of Morus nigra L. Stem Node Culture.

Phenolic compounds are strong antioxidant and antibacterial agents with great pharmacological, medicinal, nutritional, and industrial value. The potential of Morus nigra in stem node culture was investigated for the production of phenolic compounds and their elicitation with CuSO4. Individual phenolic compounds in the samples were identified and quantified by using HPLC-PDA and HPLC-MS methods, while the content of total phenolic compounds, the content of total flavonoids, and the antioxidant activity of methanolic extracts were evaluated spectrophotometrically. The highest fresh and dry weights were obtained in plantlets treated with 0.5 mM CuSO4 for 42 days. The highest total phenolic content, total flavonoid content, and antioxidant activity of the extracts were determined in stem node cultures treated with 3 mM CuSO4 for 42 days. Under the latter conditions, the predominant representatives of the caffeoylquinic acids, p-coumaric acid derivatives, kaempferol derivatives, and quercetin derivatives also achieved the highest content. The most abundant phenolic compound in all samples was the chlorogenic acid. The nodal culture of M. nigra elicited with CuSO4 could potentially be used for the industrial production of phenolic compounds, especially caffeoylquinic acids. Moreover, considering the biochemical response to CuSO4 treatment and the ability to tolerate and accumulate copper, the potential application of M. nigra in phytoremediation is also highlighted.

Distribution and risk assessment of phenols and polycyclic aromatic hydrocarbons in sediments from the continental shelf adjacent to Nile River estuaries, Egypt.

Distribution and risk assessment of phenols and polycyclic aromatic hydrocarbons in sediments from the continental shelf adjacent to Nile River estuaries, Egypt.

Volatile and phenolic profile in Pedro Ximénez sweet wines and mistelas under oxidative conditions.

In the present work, the content of volatile and phenolic compounds in sweet wines and mistelas made from sun-dried Pedro Ximénez grapes, with and without skins during alcoholic fermentation, has been studied during their storage under oxidative conditions. Three possible significant factors have been considered: oxidative storage time, type of elaboration, and presence or absence of grape skins during alcoholic fermentation. The presence or absence of skins during alcoholic fermentation showed a low influence on the content of low molecular weight phenolic compounds and furfurals during the oxidative storage in stainless steel tanks. Storage time together with type of elaboration turned out to be the most influential factors, with decreases in phenolic compounds due to possible oxidative phenomena and increases in furfurals. The evolution of phenolic compounds during oxidative aging showed to be dependent on type of elaboration, with significant decreases at the beginning of storage for mistelas. In the case of volatile compounds, a high number of them showed significant differences in relation to the type of elaboration. The presence or absence of grape skins was, mainly, significant for ethyl esters, acids and alcohols, with higher relative extent in the absence of grape skins. For these compounds, the type of elaboration-aging time interaction was also the most significant type, with significant decreases during the first 3 months of aging in mistelas. During the oxidative aging in stainless steel tanks, of sweet wines and mistelas elaborated with and without contact of grape skins during alcoholic fermentation, the main factor was oxidative aging time for phenolic and furanic compounds. Although, for volatile compounds, it was the type of elaboration, with mistelas showing a very different behavior to that of naturally sweet wines and natural sweet wines. © 2025 Society of Chemical Industry.

The Influence of Different Garlic Genotypes on Yogurt Production.

Genotypic differences influence many characteristics of garlic. These differences are particularly prominent in antioxidant, phenolic, and volatile compounds. Therefore, garlics obtained from four different regions of Turkey (Ankara, Mersin, Maraş, Taşköprü) were used in yogurt production. Gross composition, acidity, antioxidant capacity, phenolic compounds, water-holding capacity, volatile compound profile, microbiological, textural, and sensory properties of the samples were determined during 30-day storage period. The addition of garlic did not significantly change the composition, acidity, water-holding capacity, and textural properties of the samples. However, the count of lactic acid bacteria was lower in the samples with garlic compared to the control sample. In addition, depending on the garlic genotype, the addition of garlic increased the antioxidant and phenolic contents of yogurts at varying levels. Yogurt with Taşköprü garlic (sample coded D) showed the highest phenolic compound and antioxidant capacity. Similarly, sulfur compounds were detected in garlic-added yogurts at varying levels depending on the genotype. Among these compounds, diallyl disulfide was found to be at the highest level. All sulfur compounds were found at the highest levels in yogurt with Ankara and Taşköprü garlics. These yogurt samples (coded samples A and D), which were identified with high amounts of diallyl sulfide, diallyl disulfide, and diallyl trisulfide, received significantly lower taste scores from the panelists compared to the control sample due to their strong and pungent taste. This study revealed that garlic obtained from different genotypes had different effects on yogurt properties.

Yogurt with cornflower (Centaurea cyanus L.) petals as a source of antioxidant compounds and dietary fiber: Physicochemical and spectroscopic research during storage.

An extensive study was undertaken using the petals of cornflower (Centaurea cyanus [Cyani flos]) flowers in yogurt production as a source of dietary fiber and antioxidant compounds, and as a natural dye, taking into account a 21-d refrigerated storage period. An additional aim of the study was to use cornflower petals in natural form rather than an extract. Four forms of cornflower petals were tested: fresh, dried, frozen, and freeze-dried. In terms of physicochemical properties, including the amount of dietary fiber and bioactive compounds and antioxidant status, the freeze-dried form proved most beneficial. Two variants of yogurts were made, one without the addition of cornflower petals (control) and one with cornflower. The yogurts were stored for 21 d and analyzed every 7 d (at 0, 7, 14, and 21 d). In total, 4 forms of cornflower petals, 3 batches of bulk cow milk, and 288 yogurt samples were analyzed. Freeze-dried cornflower petals added to yogurt contributed to a significant increase in the content of total protein (by ∼4%), fiber (from 0.00 to 0.56 g/100 g), and selected bioactive compounds, including AA (by ∼2% in total), vitamin C (over 3-fold), and phenolic (by ∼16% in total) and mineral (on average by 8%) compounds, as well antioxidant activity. The presence of antioxidant compounds not only in the processed milk (sulfur AA, whey proteins [especially β-LA], vitamins A, E, and C, or β-carotene) but also in the petals (sulfur AA, vitamin C, and phenolic compounds) contributed to a significant increase in the antioxidant activity of fresh yogurt with cornflower (d 0 of storage; i.e., ferric reducing antioxidant power [FRAP] increased by 18%, 2,2-diphenyl-1-picrylhydrazyl by 50%, and 2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) [ABTS] by 60%), in comparison with the control yogurt. Significant changes in the content of selected bioactive compounds occurred during the 21-d storage, which affected the antioxidant activity (i.e., FRAP and ABTS increased by 20%). In addition, Fourier-transform infrared (FTIR) spectroscopy analyses of the yogurts showed mainly changes in the intensity of vibrations characteristic of this type of product, associated with polysaccharide structures, as well as vibrations associated with protein structures contained in dietary fiber. The regions with the most pronounced changes in the intensity of the bands were ∼3,300, 1,640, 1,550, and 1,240 cm-1, and there were noticeable changes at ∼1,030 cm-1. The maxima also correspond to the vibrations of C=O groups, amide bands, and the polysaccharide fraction, as well as stretching vibrations of the hydroxylic group. The analyses conducted using FTIR spectroscopy demonstrated that the product was highly stable during the refrigerated storage, as reflected in particular by the vibrations in the spectral region below 1,000 cm-3.