Photoprotection strategies that have evolved in plants to cope with high light (HL) stress provide plants with the ability to resist HL. However, it has not been clearly confirmed which ...photoprotection strategy is the major HL resistance mechanism. To reveal the major photoprotection mechanism against short-term high light (STHL), the physiological and biochemical responses of three Arabidopsis mutants (Col, chi and ans) under STHL were analyzed in this study. After STHL treatment, the most serious photosynthetic pigment damage was observed in chi plants. At the same time, the degrees of membrane and Rubisco damage in chi was the highest, followed by Col, and ans was the smallest. The results showed that ans with high antioxidant capacity showed higher resistance to STHL treatment than Col containing anthocyanins, while chi with no anthocyanin accumulation and small antioxidant capacity had the lowest resistance. In addition, the gene expression results showed that plants tend to synthesize anthocyanin precursor flavonoids with antioxidant capacity under STHL stress. To further determine the major mechanism of photoprotection under STHL, we also analyzed Arabidopsis lines (Col, CHS1, CHS2 and tt4) that had the same anthocyanin content but different antioxidant capacities. It was found that CHS2 with high antioxidant capacity had higher cell viability, smaller maximal quantum yield of PSII photochemistry (Fv/Fm) reduction and less reactive oxygen species (ROS) accumulation under HL treatment of their mesophyll protoplasts. Therefore, the antioxidant capacity provided by antioxidant substances was the major mechanism of plant photoprotection under STHL treatment.
•The antioxidant capacity was more important than light shielding effect under STHL.•Plants tend to synthesize anthocyanin precursor flavonoids with antioxidant capacity under STHL.•A higher antioxidant capacity correlated with a higher resistance index.•A higher antioxidant capacity correlated with a higher the mesophyll protoplast survival.
In this study, the effect of baking conditions and dough formulations on phenolic compounds, antioxidant capacity and color of cookies made from anthocyanin-rich corn flour were investigated. The ...control cookies were prepared from dark-red popping corn, blue popping corn and blue-standard corn flour according AACC method 10–54 and baked at 200 °C for 7 and 10 min. In control corn cookies, the content of total flavonoids and anthocyanins, as free water-soluble phenolic compounds, was reduced by applied baking conditions. Our results show that citric acid significantly increased the total flavonoids and anthocyanins content in the cookies prepared from blue popping corn and blue-standard corn. Compared with the control cookies baked at 200 °C for 7 min, the cookies prepared with 0.5 g/100 g added citric acid and baked at 150 °C for 12 min had higher contents of total flavonoids and anthocyanins by 60 and 70%, respectively. However, as a result of Maillard reaction inhibition at low pH, antioxidant capacity of anthocyanins-rich blue popping corn and blue standard corn cookies with 0.5 and 1 g/100 g citric acid was lower by 56 and 39%, respectively, compared to antioxidant capacity of their control cookies baked at 200 °C for 10 min.
•Baking conditions affected anthocyanins degradation and Maillard reaction products formation.•Citric acid increased the phenolic compounds in corn cookies by anthocyanins stabilization.•Citric acid improved accessibility of the anthocyanins.•Maillard reaction was inhibited at low pH.•Maillard reaction had crucial influence on the antioxidant capacity in corn cookies.
This study investigated the basic and functional compositions, volatile compounds, intelligent sensory characteristics and antioxidant capacity of the commercial ‘Marselan’ wines from seven Chinese ...regions. The Nei Mongol wines featured high total reducing sugar, fructose, ammonia nitrogen, 17 monomeric phenolic acids contents and elevated antioxidant capacity. Malic acid was the only organic acid that significantly different in all seven regions. Malvidin-3-O-glucoside and trans-peonidin-3-O-(6-O-p-coumaryl)-glucoside showed the highest and lowest contents. A total of 102 volatiles was detected and Hebei wines had the most (91). Hexanoic acid and β-damascenone were considered to have high potential sensory effects (OAV ≥ 1) as compounds detected in all regions. Floral, sweet, and fruity were the most important aroma series. E-eye analysis revealed the colors of the samples tended to yellowish with aging. PCA and OPLS-DA based on the basic wine composition, monomeric organic acids and anthocyanins allowed achieving a discrimination of the seven regions, respectively.
•Quality characteristics differed in Marselan wines from the seven regions in China.•β-Damascenone and ionone were two compounds in Marselan wines that had high OAVs.•Floral, sweet, and fruity are the strongest aroma series of Marselan wines.•There were differences in the profiles of the e-nose between the seven regions.•The models based on several parameters can clearly distinguish the regions.
Abstract The use of intensive systems in aquaculture causes an increase in environmental stress agents, reducing water quality and facilitating the appearance of pathologies in individuals. In this ...context, the selection of ingredients is a key strategy in managing the quality of aquafeed and the cultivation of aquaculture species. Considering this, wine by-products can be a potential functional ingredient due to several particular characteristics, such as their low cost, large volumes produced, and for being a natural source of bioactive compounds with antioxidant activity. The present study developed different experiments focused on evaluating the benefits of feeding juvenile European sea bass during 5 weeks with feeds incorporating 0.4% red wine grape pomace (GP). At the end of the feeding period, potential modifications in metabolism, immunological and oxidative status, and functionality of intestinal microbiota were assessed as well as the potential protective effect against oxidation in fish fillets during 6 days of cold storage (4 °C). In addition, the preservative effect of GP on the feed when stored for a period of 12 weeks at two different temperatures (4 °C and 25 °C) was evaluated. The results demonstrated that the inclusion of GP in feeds for European sea bass prevents oxidation when stored at room temperature. In addition, a general improvement in the physiological and immunological status, as well as fillet quality, was evidenced.
Chamomile (
L.) dried flowers contain a group of interesting biologically active compounds such as sesquiterpenes, flavonoids, coumarins, vitamins, phenolic acids and glucosides. Therefore, the aim ...of the present study was to characterize the composition in bioactive compounds (specialized metabolites) present in water and ethanol extracts of chamomile flowers, together with monitoring the impact of different extraction techniques (conventional vs. ultrasound-assisted extraction (UAE)) on the parameters under investigation. UAE treatment significantly decreased the extraction time of bioactive compounds from herbal material. Polyphenolic compounds content and antioxidant capacity were significantly higher in UAE extracts. Moreover, solvent type had a significant impact on the specialized metabolites content, while the highest vitamin C and polyphenols content were recorded in 50% ethanol (
/
) extracts. Optimization of basic extraction factors: solvent type, temperature and technique is crucial for obtaining the extracts with the highest content of specialized metabolites and antioxidant capacity.
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•The protein and polyphenol contents of conjugates were influenced by the number of –OH group.•Anchovy protein hydrolysate (APH)-Catechin/Gallic acids showed better antioxidant ...capacities.•APH-Catechin at ratio of 5:1 yielded the most bioactive peptides during conjugation.•The physical stability of fish oil emulsions was enhanced by APH-Tannic Acid 5:1 conjugate.•The oxidative stability was elevated by APH-Gallic acid 10:1 conjugate.
Conjugation between peptides and polyphenols could improve their bioactive and functional properties. The improvement effects of anchovy protein hydrolysates (APH) -polyphenol (catechin (CA), gallic acid (GA), tannic acid (TA)) conjugates were investigated. The content of protein and polyphenols and ratio of polyphenols/peptides in conjugates increased as the number of OH group increased with TA > CA > GA. Results showed that APH-CA and APH-GA exhibited the highest ORAC and ABTS+ scavenging capacity, respectively. Mass spectrometry analysis suggested the highest number of bioactive peptides were identified in APH-CA 5:1 (APH/polyphenols). The physical stability of fish oil emulsions during storage was significantly enhanced by TA 5:1 conjugate followed by CA 5:1 conjugate. The oxidative stability was remarkably elevated by APH-GA 10:1. This was due to the antioxidant capacity and the peptides adsorbed at the interfacial. This study demonstrated that APH-polyphenol conjugates could bring the possibility of utilizing peptides-polyphenols in the nutraceutical and functional food ingredient fields.
Numerous assays were developed to measure the antioxidant activity, but each has limitations and the results obtained by different methods are not always comparable. Popular examples are the DPPH and ...ABTS assay. Our aim was to study similarities and differences of these two assay regarding the measured antioxidant potentials of 24 phenolic compounds using the same measurement and evaluation methods. This should allow conclusions to be drawn as to whether one of the assays is more suitable for measuring specific subgroups like phenolic acids, flavonols, flavanones, dihydrochalcones or flavanols. The assays showed common trends for the mean values of most of the subgroups. Some dihydrochalcones and flavanones did not react with the DPPH radical in contrast to the ABTS radical, leading to significant differences. Therefore, to determine the antioxidant potential of dihydrochalcone or flavanone-rich extracts, the ABTS assay should be preferred. We found that the results of the flavonoids in the DPPH assay were dependent on the Bors criteria, whereas the structure-activity relationship in the ABTS assay was not clear. For the phenolic acids, the results in the ABTS assay were only high for pyrogallol structures, while the DPPH assay was mainly determined by the number of OH groups.
The research examined the impact of adding potassium diformate (KDF) and sodium diformate (NDF) to the diet of Siberian sturgeon (Acipenser baerii) and how it influenced their antioxidant levels and ...immune responses. The fish (n = 315; 17.85 ± 0.2 g initial weight) were fed with seven diets for 56 days, including a control group (unsupplemented diet) and groups with varying levels of KDF (0.15, 0.3, and 0.5%) and NDF (0.15, 0.3, and 0.5%). After the feeding trial, the groups that consumed KDF or NDF demonstrated a dose-responsive elevation in serum superoxide dismutase, catalase, and glutathione peroxidase levels, along with an overall increase in total antioxidant capacity compared to the control group (P < 0.05). These groups also had lower malondialdehyde levels (P < 0.05) and improved immune functions, including higher levels of immunoglobulin M, total protein, albumin, globulin, the activities of lysozyme, respiratory burst, and alternative complement (P < 0.05). Also, the serum bactericidal activity experienced a significant increase (maximum in 0.5% NDF treatment) in the groups subjected to experimental feeding compared to the control group (P < 0.05). The transcription levels of interleukin-1 beta (IL-1β), interleukin 8 (IL-8), tumor necrosis factor-alpha (TNF-α), high mobility group box 1 (AbHMGB1), and high mobility group box 2 (AbHMGB2) genes in the head kidney were significantly upregulated in fish fed with different doses of KDF or NDF compared to the control group (P < 0.05). The most significant upregulation was observed in the group that received 0.5% NDF. Moreover, the experimental groups demonstrated a lower cumulative mortality rate of the fish following exposure to Aeromonas hydrophila AB005 infection compared to the control group (P < 0.05), with the lowest mortality rate observed in the 0.5% NDF or KDF group. Overall, the results suggest that dietary KDF or NDF, especially 0.5% NDF, are promising as environmentally friendly options and sustainable immunostimulants in Siberian sturgeon aquaculture.
•Potassium diformate or sodium diformate improved humoral immunity in Acipenser baerii.•Antioxidant capacity was boosted with dietary potassium or sodium diformate (KDF or NDF).•Increased expression of cytokines gene was observed after dietary supplementation with KDF or NDF.•High-mobility group protein genes were upregulated with dietary KDF or NDF.•Feeding with KDF and NDF decreased mortality rates in A. baerii after Aeromonas hydrophila infection.
The stability of (−)-epigallocatechin gallate (EGCG) in an aqueous system with a pH range of 2.2–8.0 was investigated at temperatures ranging from 25 to 165 °C. Within these ranges, the stability of ...EGCG decreased with increasing pH and temperature. The lowest (1.06 × 10−7 s−1) and highest (8.83 × 10−2 s−1) degradation rate constants were obtained at pH 3 and 25 °C, and pH 8 and 135 °C, respectively. Epimerization rate constants between EGCG and (−)-gallocatechin gallate (GCG) both increased with increasing temperature and pH. However, the rate of epimerization from EGCG to GCG was found to always be higher than that of GCG to EGCG. To further evaluate the effects of pH and temperature on catechins, antioxidant capacity analysis was conducted on thermally processed EGCG solutions using DPPH and ABTS assays. Changes in the total antioxidant capacity of samples after thermal treatments under various pH values were found to be insignificant.
•Stability of EGCG decreased with increasing pH and temperature.•The lowest and highest degradation rate constants were obtained.•Epimerization rate constants increased with increasing temperature and pH.•Epimerization rates from EGCG to GCG were always higher than that of GCG to EGCG.•Changes in the total antioxidant capacities of samples were insignificant.
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