Fulvic acid foliar application: a novel approach enhancing antioxidant capacity and nutritional quality of pistachio (Pistacia vera L.).

BACKGROUND: The global growth of pistachio production has prompted exploration into sustainable agricultural practices, on the application of humic substances such as fulvic acid in enhancing the quality of horticultural crops. The present study was carried out in Qom province, Iran, on 20 years old pistachio (Pistacia vera L. cv. Kaleh-Ghoochi) trees and investigated the impact of foliar spraying of fulvic acid at varying concentrations (1.5, 3, and 4.5 g L- 1) on the antioxidant and quality properties of pistachio. The different concentrations of fulvic acid were applied at two key stages: at the initiation of pistachio kernel formation (late June) and the development stage of pistachio kernel (late August), as well as at both time points. Following harvest at the horticulturally mature phase, various parameters, including total phenols, flavonoids, soluble proteins, soluble carbohydrate content, antioxidant capacity, and antioxidant enzyme activity, were assessed. RESULTS: Results indicated that foliar application of fulvic acid, particularly at 1.5 g L- 1 during both late June and August, effectively increased phenolic compounds (31.8%) and flavonoid content (24.53%). Additionally, this treatment also augmented antioxidant capacity and heightened the activity of catalase (CAT) (37.56%), ascorbate peroxidase (APX) (63.86%), and superoxide dismutase (SOD) (76.45%). Conversely, peroxidase (POX) (41.54%) activity was reduced in fulvic acid-treated nuts compared with controls. Moreover, the content of chlorophyll (45%) and carotenoids (46.7%) was enhanced using this organic fertilizer. In terms of mineral elements, the increment was observed in zinc (Zn) (58.23%) and potassium (K) (28.12%) amounts in treated nuts. Additionally, foliar application of fulvic acid led to elevated levels of soluble carbohydrates and proteins in treated nuts. CONCLUSIONS: In the present study, application of fulvic acid resulted in enhancement of antioxidant activity and quality traits of pistachio nut through an increase in total phenol, flavonoids, chlorophyll, carotenoids, K, Zn, and also activity of antioxidant enzymes. Therefore, use of fulvic acid emerges as a promising strategy to enhance the quality and nutritional attributes of pistachios, contributing to sustainable agricultural practices and improved crop outcomes.

Antioxidant capacity sources of soils under different land uses.

Antioxidants (AOX) in soils originate mainly from secondary plant metabolites and are pivotal in many redox processes in environment, maintaining soil quality. Still, little is known about the influence of land uses on their accumulation in soil. The aim of the paper was to determine the content of these redox-active compounds in the extracts of A horizons of abandoned fallows, arable and woodland soils. Total antioxidant capacity (TAC) of soils under various uses and vegetation was evaluated in different soil extracts using Folin-Ciocâlteu method. The contribution of humic acids to TAC was determined and antioxidant profiles estimated using the chromatographic GC-MS method. Forest soils exhibited the highest TAC (15.5 mg g-1) and AOX contents (4.34 mg g-1), which were positively correlated with soil organic carbon content. It was estimated that humic acids contribute to over 50% of TAC in soils. The main phenolics in woodland A horizons were isovanillic and p-hydroxybenzoic acid (p-HA), while esculetin and p-HA predominated in the abandoned fallows due to the prevalence of herbaceous vegetation. Cultivated soils were the most abundant in p-HA (56.42%). In the studied topsoils, there were considerable amounts of aliphatic organic matter, which role in redox processes should be further evaluated.

Dietary total antioxidant capacity of Moroccan Type 2 Diabetes Mellitus patients.

AIMS: A new approach to a healthy diet is the assessment of dietary Total Antioxidant Capacity (TAC). The aim of this study was to assess the dietary TAC among Moroccan Type 2 Diabetes Mellitus (T2DM) patients and identify the main food sources contributing to the total antioxidant capacity intake. METHODS: A total of 254 patients with T2DM was included in the study. The usual dietary intakes were assessed by means of a validated food frequency questionnaire. The dietary TAC was estimated using published databases of the antioxidant content of foods measured by the FRAP (ferric ion reducing antioxidant potential) method. RESULTS: The mean (SD) dietary TAC of the studied type 2 diabetes patients was 10.86 (3.42) mmol/day. Correlation analyses showed a positive association between dietary TAC and the consumption of healthy food groups, such as fruits and vegetables. Tea and coffee beverages (38.6%), vegetables (21.9%), cereals and pulses (18.8%), fruits and fruit juices (12.4%) were major food sources of dietary antioxidant intake. The relatively short list of twenty food items that contributed most to dietary TAC presented an important explanation of roughly 94%. These included tea, coffee, broad beans, artichoke, pepper, beetroot, sweet potatoes, pomegranate, mandarin, figs, strawberry, orange juice, olives, cashew nuts, almonds, sunflower seeds, dchicha and white beans. CONCLUSIONS: This study supplies baseline dietary TAC data for Moroccan T2DM patients that may help to elucidate which aspects of the eating habits and behaviours require improvement and provide the opportunity to develop dietary guidelines as part of the nutritional diabetes management.

Temperature-resilient and sustainable Mn-MOF oxidase-like nanozyme (UoZ-4) for total antioxidant capacity sensing in some citrus fruits: Breaking the temperature barrier.

Current nanozyme applications rely heavily on peroxidase-like nanozymes and are limited to a specific temperature range, despite notable advancements in nanozyme development. In this work, we designed novel Mn-based metal organic frameworks (UoZ-4), with excellent oxidase mimic activity towards common substrates. UoZ-4 showed excellent oxidase-like activity (with Km 0.072 mM) in a wide range of temperature, from 10 °C to 100 °C with almost no activity loss, making it a very strong candidate for psychrophilic and thermophilic applications. Ascorbic acid, cysteine, and glutathione could quench the appearance of the blue color of oxTMB, led us to design a visual-based sensing platform for detection of total antioxidant capacity (TAC) in cold, mild and hot conditions. The visual mode successfully assessed TAC in citrus fruits with satisfactory recovery and precisions. Cold/hot adapted and magnetic property will broaden the horizon of nanozyme applications and breaks the notion of the temperature limitation of enzymes.

Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste.

The current effort to valorize waste byproducts to increase sustainability and reduce agricultural loss has stimulated interest in potential utilization of waste components as health-promoting supplements. Tomato seeds are often discarded in tomato pomace, a byproduct of tomato processing, yet these seeds are known to contain an array of compounds with biological activity and prebiotic potential. Here, extract from tomato seeds (TSE), acquired from pomace, was evaluated for their ability to effect changes on the gut microbiota using an ex vivo strategy. The results found that TSE significantly increased levels of the beneficial taxa Bifidobacteriaceae in a donor-independent manner, from a range of 18.6-24.0% to 27.0-51.6% relative abundance following treatment, yet the specific strain of Bifidobacteriaceae enhanced was inter-individually variable. These structural changes corresponded with a significant increase in total short-chain fatty acids, specifically acetate and propionate, from an average of 13.3 to 22.8 mmol/L and 4.6 to 7.4 mmol/L, respectively. Together, these results demonstrated that TSE has prebiotic potential by shaping the gut microbiota in a donor-independent manner that may be beneficial to human health. These findings provide a novel application for TSE harvested from tomato pomace and demonstrate the potential to further valorize tomato waste products.

Characterization and Antioxidant and Antibacterial Activities of Carboxymethylated Tamarind Seed Polysaccharide Composite Films Incorporated with ε-Polylysine and Their Application in Fresh-Cut Green Bell Pepper Preservation.

Traditional petroleum-based food-packaging materials have poor permeability, limited active packaging properties, and difficulty in biodegradation, limiting their application. We developed a carboxymethylated tamarind seed polysaccharide composite film incorporated with ε-polylysine (CTPε) for better application in fresh-cut agricultural products. The CTPε films exhibit excellent water vapor barrier properties, but the mechanical properties are slightly reduced. Fourier transform infrared spectroscopy and X-ray diffraction spectra indicate the formation of hydrogen bonds between ε-PL and CTP, leading to their internal reorganization and dense network structure. With the increase of ε-PL concentration, composite films showed notable inhibition of postharvest pathogenic fungi and bacteria, a significant enhancement of 2,2'- azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical-scavenging activity, and gradual improvement of wettability performance. Cytotoxicity experiments confirmed the favorable biocompatibility when ε-PL was added at 0.3% (CTPε2). In fresh-cut bell pepper preservation experiments, the CTPε2 coating effectively delayed weight loss and malondialdehyde increase preserved the hardness, color, and nutrients of fresh-cut peppers and prolonged the shelf life of the fresh-cut peppers, as compared with the control group. Therefore, CTPε composite films are expected to be a valuable packaging material for extending the shelf life of freshly cut agricultural products.

Phytochemical screening of Podocarpus lambertii Klotzch ex Endl. leaf extracts and potential antimicrobial, antioxidant and antibiofilm activity.

Species of the genus Podocarpus L'Hér. ex Pers.present biological activities, such as analgesic, antioxidant, antifungal, acting in the fight against anemia, depurative and fortifying. Podocarpus lambertii Klotzch ex Endl. is a Brazilian native species popularly known as maritime pine and lacks information about its phytochemical profile and possible biological activities. The study was conducted to determine the phytochemical composition of soluble plant extracts of acetone (EA), ethyl acetate (EAE) and hexane (HE) from leaves of P. lambertii; evaluate the antimicrobial potential by the broth microdilution technique; antioxidant potential by the DPPH method, as well as to evaluate the biofilm inhibition capacity by the crystal violet assay and reduction of the yellow tetrazolium salt (MTT). Phytochemical screening detected the presence of flavonoids, triterpenoids, steroids, tannins, alkaloids and saponins. All extracts showed antimicrobial activity on the microorganisms tested, and the EA showed the best results. High free radical scavenging potential was observed only in EAE (96.35%). The antibiofilm potential was observed in the EAE extract. The results contribute to the knowledge of the species and indicate the potential of P. lambertii extracts as a source of plant bioactives for the development of new alternative strategies to control resistant microorganisms.

The potential of lemon peel powder as an additive in layer quails (Coturnix coturnix Japonica): An experimental study.

The current research intended to examine the impact of dietary lemon peel powder (LPP) on laying quail performance, egg quality criteria, and the antioxidant capacity of the yolk. A total of 120 female Japanese quails (272.6±9.3 g), aged 21 weeks, were allotted to 6 trial groups, each with 5 replicates of 4 quails. Additions of 0, 1, 2, 3, 4, or 5 g/kg of LPP to the basal diet were used to create the treatment groups. Quails were fed ad libitum for 70 days. Neither performance parameters nor egg production was affected by LPP. However, eggshell-breaking strength improved by adding 2 g/kg LPP to the diet, but worsened at 5 g/kg. Moreover, the relative weight of eggshell and yolk L* value decreased with the treatments. Dietary LPP enhanced oxidative stability, reducing malondialdehyde (MDA) and increasing 1,1-diphenyl-2-picrylhydrazyl (DPPH) yolk values. The current study demonstrated that LPP, a safe and easily accessible agricultural by-product, enhanced eggshell quality when it was included in the diet of laying quails at doses of 2 g/kg. In contrast, improvement of yolk antioxidant capacity required increased amounts of LPP (4 g/kg). LPP could be advantageous to animal nutrition as an adequate substitute to reduce waste by-products.

Effects of soil pH on the growth, soil nutrient composition, and rhizosphere microbiome of Ageratina adenophora.

Ageratina adenophora is an invasive weed species found in many countries. Methods to control the spread of this weed have been largely unsuccessful. Soil pH is the most important soil factor affecting the availability of nutrients for plant and impacting its growth. Understanding the mechanisms of the influence of soil pH on the growth of A. adenophora may help to develop effective control measures. In this study, we artificially changed the soil pH in pot experiments for A. adenophora. We studied the effects of acidic (pH 5.5), weakly acidic (pH 6.5), neutral (pH 7.2), and alkaline (pH 9.0) soils on the growth, availability of soil nutrients, activity of antioxidant enzymes, levels of redox markers in the leaves, and the structure and diversity of the rhizosphere microbiome. Soil with a pH 7.2 had a higher (47.8%) below-ground height versus soils of pH 5.5 at day 10; plant had a higher (11.3%) above-ground height in pH 7.2 soils than pH 9.0 soils at day 90; no differences in the fresh and dry weights of its above- and belowground parts, plant heights, and root lengths were observed in plants growing in acid, alkaline, or neutral pH soil were observed at day 180. Correspondingly, the antioxidant enzymes SOD (superoxide dismutase), POD (peroxidase), CAT (catalase) and redox markers GSH (glutathione) and MDA (malondialdehyde) were measured in the leaves. Significant differences existed in the activities of CAT and the levels of GSH between those growing in acidic and alkaline soils and those in neutral pH soil at day 90; however, only lower (36.8%) CAT activities in those grown at pH 5.5 than those grown at pH 7.2 were found at day 180. Similarly, significant differences in available P (16.89 vs 3.04 mg Kg-1) and total K (3.67 vs 0.96 mg Kg-1), total P (0.37 vs 0.25 g Kg-1) and total N (0.45 vs 1.09 g Kg-1) concentrations were found between the rhizosphere soils of A. adenophora grown at pH 9.0 and 7.2 at day 90; no such differences were seen at day 180. High throughput analyses of the 16S rRNA and ITS fragments showed that the rhizosphere microbiome diversity and composition under different soil pH conditions changed over 180 days. The rhizosphere microbiomes differed in diversity, phylum, and generic composition and population interactions under acid and alkaline conditions versus those grown in neutral soils. Soil pH had a greater impact on the diversity and composition of the prokaryotic rhizosphere communities than those of the fungal communities. A. adenophora responded successfully to pH stress by changing the diversity and composition of the rhizosphere microbiome to maintain a balanced nutrient supply to support its normal growth. The unusual pH tolerance of A. adenophora may be one crucial reason for its successful invasion. Our results suggest that attempts use soil pH to control its invasion by changing the soil pH (for example, using lime) will fail.

Quality and functional properties of bread containing the addition of probiotically fermented Cicer arietinum.

This study aimed to determine the impact of supplementation with probiotically fermented chickpea (Cicer arietinum L) seeds on the quality parameters and functional characteristics of wheat bread. The addition of chickpea seeds caused significant changes in the chemical composition of the control wheat bread. The legume-supplemented products exhibited higher values of a* and b* color parameters and higher hardness after 24 h of storage than the control. The application of fermented or unfermented chickpeas contributed to an increase in total polyphenol and flavonoid contents, iron chelating capacity, and antioxidant properties of the final product. The variant containing unfermented seeds had the highest riboflavin content (29.53 ± 1.11 µg/100 g d.w.), Trolox equivalent antioxidant capacity (227.02 ± 7.29 µmol·L-1 TX/100 g d.w.), and free radical scavenging activity (71.37 ± 1.30 % DPPH inhibition). The results of this preliminary research have practical importance in the production of innovative bakery products with potential properties of functional food.

Sequential extraction of anthocyanins and pectin from jabuticaba (Plinia cauliflora) peel: Peel pretreatment effect and ultrasound-assisted extraction.

The jabuticaba bark is rich in anthocyanins and fibers, and its use may be of industrial interest. In the food sector, its used as an ingredient in the production of fermented products, liqueurs or enriched flours. It also has pharmaceutical and cosmetic applications. The objective was to evaluate the effect of pretreatment and fresh use of jabuticaba peels in the extraction of total phenolic compound (TPC) and total anthocyanin (TA) contents with and without ultrasound assistance and in the sequential extraction of pectin from the residue. In the TPC and TA extraction, a 3x2 factorial design was used. For conventional anthocyanin extraction (CAE), occurred in an incubator under agitation. For ultrasound-assisted anthocyanin extraction (UAE) was utilized an ultrasonic homogenizer with probe (20 kHz, 160 W). The extracts were quantified (TPC, TA, antioxidant activity and color). The residues were characterized and used for sequential pectin extraction, which was quantified and characterized. The results were subjected to analysis of variance. Fresh jabuticaba peel is a residue that can be used to sequentially extract phenolic compounds, particularly anthocyanins and pectin. The use of ultrasound (UAE) was less efficient than CAE for extracting TPC and TA or performing sequential extraction on all pretreatment peels.

A novel optimized eco-friendly simple spectrofluorimetric method for the determination of total catechins in green tea extract: Application to commercial tablet.

Green tea extract (GTE) contains antioxidants that are present in green tea. The active constituents of green tea extract are catechins. This study demonstrates a spectrofluorimetric method for measuring GTE's catechin concentration based on its native fluorescence. To design a quick, sensitive, and ecological spectrofluorimetric approach, all features were investigated and adjusted. This method relies on determining the GTE ethanolic solution's native fluorescence at 312 nm after excitation at 227 nm. The calibration graph displayed a linear regression for values between 0.05 and 1.0 µg mL-1. The detection and quantification limits of the proposed technique were 0.008 and 0.026 µg mL-1, respectively. Two pure catechins present in GTE, (-)-epicatechin and (-)-epigallocatechin gallate, were examined by the proposed method. The analytical estimation of GTE in the pharmaceutical tablet was achieved effectively using this approach. An adequate degree of agreement was found when the findings were compared to those obtained by the comparative technique. Therefore, the novel strategy may be used in the GTE quality control study with minimal risks to people or the environment. The quantum yields of catechins were estimated. The validated technique was accepted by the International Council of Harmonization criteria.

Chemoprofiling and medicinal potential of underutilized leaves of Cyperus scariosus.

Agro-waste is the outcome of the under-utilization of bioresources and a lack of knowledge to re-use this waste in proper ways or a circular economy approach. In the Indian medicinal system, the root of Cyperus scariosus (CS) is used at a large scale due to their vital medicinal properties. Unfortunately, the aerial part of CS is treated as agro-waste and is an under-utilized bioresource. Due to a lack of knowledge, CS is treated as a weed. This present study is the first ever attempt to explore CS leaves as medicinally and a nutrient rich source. To determine the food and nutritional values of the neglected part of Cyperus scariosus R.Br. (CS), i.e. CS leaves, phytochemicals and metal ions of CS were quantified by newly developed HPLC and ICPOES-based methods. The content of the phytochemicals observed in HPLC analysis for caffeic acid, catechin, epicatechin, trans-p-coumaric acid, and trans-ferulic acid was 10.51, 276.15, 279.09, 70.53, and 36.83 µg/g, respectively. In GC-MS/MS analysis, fatty acids including linolenic acid, phytol, palmitic acid, etc. were identified. In ICPOES analysis, the significant content of Na, K, Ca, Cu, Fe, Mg, Mn, and Zn was observed. The TPC and TFC of the CS leaves was 17.933 mg GAE eq./g and 130.767 mg QCE eq./g along with an IC50 value of 2.78 mg/mL in the DPPH assay and better antacid activity was measured than the standard (CaCO3). The methanolic extract of CS leaves showed anti-microbial activity against Staphylococcus aureus (15 ± 2 mm), Pseudomonas aeruginosa (12 ± 2 mm) and Escherichia coli (10 ± 2 mm). In silico studies confirmed the in vitro results obtained from the antioxidant, antiacid, and anti-microbial studies. In addition, in silico studies revealed the anti-cancerous and anti-inflammatory potential of the CS leaves. This study, thus, demonstrated the medicinal significance of the under-utilized part of CS and the conversion of agro-waste into mankind activity as a pharmaceutical potent material. Consequently, the present study highlighted that CS leaves have medicinal importance with good nutritional utility and have a large potential in the pharmaceutical industry along with improving bio-valorization and the environment.

Functional Evaluation of Fermented Rice Bran and Extracted Rice Bran Oil Addressing for Human Health Benefit.

Rice bran (RB) and rice bran oil (RBO) are exploring as prominent food component worldwide and their compositional variation is being varied among the world due to regional and production process. In this study, Fermented Rice Bran (FRB) was produced by employing edible gram-positive bacteria (Lactobacillus acidophilus, Lactobacillus bulgaricus and Bifidobacterium bifidum) at 125×10 5 spore g -1 of rice bran, and investigated to evaluate nutritional quality. The Crude Rice Bran Oil (CRBO) was extracted from RB and its quality was also investigated compared to market available rice bran oil (MRBO) in Bangladesh. We found that fermentation of rice bran with lactic acid bacteria increased total proteins (29.52%), fat (5.38%), ash (48.47%), crude fiber (38.96%), and moisture (61.04%) and reduced the carbohydrate content (36.61%). We also found that essential amino acids (Threonine, valine, leucine, lysine, histidine and phenylalanine) and non-essential amino acids (alanine, aspartate, glycine, glutamine, serine and tyrosine) were increased in FRB except methionine and proline. Moreover, total phenolic content, tannin content, flavonoid content and antioxidant activity were increased in FRB. The RBO analysis showed that γ-oryzanol content (10.00 mg/g) were found in CRBO compared to MRBO (ranging 7.40 to 12.70 mg/g) and Vitamin-E content 0.20% were found higher in CRBO compared to MRBO (ranging 0.097 to 0.12%). The total saturated (25.16%) and total unsaturated fatty acids (74.44%) were found in CRBO whereas MRBO contained total saturated (22.08 to 24.13%) and total unsaturated fatty acids (71.91 to 83.29%) respectively. The physiochemical parameters (density, refractive index, iodine value) were found satisfactory in all sample except acid value and peroxide value higher in CRBO. Heavy metal concentration was found within an acceptable range in both CRBO and MRBO. Thus FRB and RBO could be value added food supplement for human health.

Does dietary total antioxidant capacity relate to oxidative stress levels in water immersion during labor? A case-control study.

OBJECTIVE: The aim of this study was to investigate the effect of water immersion during the first stage of labor on maternal and neonatal oxidative stress and the association between serum and dietary total antioxidant capacity. METHODS: Women were divided into two groups: those immersed in water during the first stage of labor (n=30) and those who had conventional birth (n=33). Total oxidative stress and total antioxidant status levels were examined in antepartum and postpartum maternal serum and neonatal cord blood samples. Dietary total antioxidant capacity was determined by the food frequency questionnaire. RESULTS: Vitamin C and dietary total antioxidant capacity consumption were found to be higher in the water immersion group (106.92 mg/day and 18.94 mmol/gün, respectively) than the conventional birth group (92.69 mg/day and 15.99 mmol/gün, respectively) (p<0.05). Women immersed in water during the first stage of labor had lower total oxidative stress levels in antepartum and postpartum maternal serum and neonatal cord blood samples than those who had conventional birth (5.43±2.42 mmol/L and 5.59±3.35 mmol/L vs. 8.58±5.53 mmol/L and 12.68±16.58 mmol/L; p<0.05). Dietary total antioxidant capacity was found to be negatively correlated with total oxidative stress levels in antepartum and postpartum maternal serum and neonatal cord blood samples (p=0.012, p=0.047, p=0.035, and p<0.05). CONCLUSION: Women immersed in water during the first stage of labor had lower total oxidative stress levels in their postnatal maternal serum and neonatal cord blood samples and dietary total antioxidant capacity was also a factor associated with low total oxidative stress levels.

Chemical composition and potential antioxidant, anti-inflammatory, and analgesic efficacy of Cistus albidus L.

This study aims to assess the chemical composition of the aqueous extract of Cistus albidus L. leaves, as well as the potential of aqueous and hydroethanol extracts of the leaves and seeds as analgesic, anti--inflammatory, and antioxidant agents. The contents of phenolics and inorganic constituents were determined in C. albidus seeds and leaves; antioxidant capacity was assessed by 3 complementary and diverse tests. The carrageenan-induced paw edema technique was used to investigate the anti-inflammatory effect in vivo, and albumin denaturation to evaluate the anti-inflammatory effect in vitro. The acetic acid-induced contortion test, the tail-flick test, and the plantar test were used to assess the analgesic effi cacy in vivo. Chemical analysis was performed by UPLC-MS/MS to quantify several phenolic compounds including catechin (1,627.6 mg kg-1), quercitrin (1,235.8 mg kg-1) and gallic acid (628. 2 mg kg-1). The ICP analysis revealed that potassium and calcium were the main inorganic components in the seeds and leaves of C. albidus. The hydroethanolic extract of the leaves showed the highest content of polyphenols/flavonoids, whereas the highest value of proantho cyanidins was detected in the aqueous extract of the seeds. All extracts showed potent antioxidant activity related to different phenolic compounds (quercetin, gallic acid, astragalin, catechin, and rutin). The aqueous extract of the leaves strongly inhibited paw edema (76.1 %) after 6 h of treatment and showed maximal inhibition of protein denaturation (191.0 µg mL-1 for 50 % inhibition) and analgesic activity in different nociceptive models. The presented data reveal that C. albidus extracts potentially show antioxidant, anti-inflammatory, and analgesic activities that could confirm the traditional use of this plant.

Fast FRAP-SIA method to determine antioxidant capacity.

One of the most used methods to measure antioxidant capacity in food is the ferric reducing antioxidant power (FRAP) test, which is simple, sensitive, and economical, nevertheless has long analysis times, causing measurement errors due to the instability of the FRAP reagent due to its precipitation sequential injection analysis (SIA) is a flow technique that can correct these disadvantages because it is more quickly. So, a novel FRAP-SIA method was developed to evaluate the antioxidant capacity. The system was optimized using a central composite design for hydrodynamic and chemical factors, resulting in a flow rate of 35 µL s-1, and aspirate volumes of 33 µL-38 µL-33 µL for the sequence (FRAP-Antioxidant-FRAP). FRAP reagent was prepared with an HCl solution at 0.005 mol L-1, improving its stability 24 times, concerning when it is in acetate buffer at pH 3.6. The method showed excellent accuracy (RSD <3%) with a LOD of 1.0 µmol L-1 of Trolox for a linear range of 5-120 µmol L-1. The reaction time was diminished by 96% concerning the FRAP-microplate assay (from 30 min to 1.2 min). The method was applied in beverages and extracts, obtaining recovery values ranging from 91.24 to 114.22%.

Polyphenolic profile and in vitro biological activity of Serbian orange (skin fermented white) wines.

Orange wines are made from white grapes, but with prolonged skin contact during fermentation. Available data on their composition and potential health benefits are limited, so polyphenolic profile (HPLC analysis) and in vitro biological activities (enzyme inhibition, antioxidant, and anti-inflammatory) of 24 Serbian orange wines were analyzed, including the correlation between determined composition and bioactivities. The wines displayed distinct polyphenolic profiles, enabling partial differentiation based on overall polyphenol content, including dominant components (catechin, gallic and caffeic acids), along with occasional occurrences of anthocyanins. However, no discernible distinctions were noted based on grape varieties, vintage, or producer. All twenty-four orange wines showed a reasonable inhibition of digestive enzymes and lipid peroxidation, twenty-one samples reduced ROS generation in the cell-based assay, but only two suppressed both PGE2 and TXA2 production in U937 cells, implicating possible functional food properties. No significant correlation between polyphenolic profile and determined biological activities was noticed.

Effects of post-fermentation addition of green tea extract for sulfur dioxide replacement on Sauvignon Blanc wine phenolic composition, antioxidant capacity, colour, and mouthfeel attributes.

This study examines the feasibility of replacing SO2 in a New Zealand Sauvignon Blanc wine with a green tea extract. The treatments included the control with no preservatives (C), the addition of green tea extract at 0.1 and 0.2 g/L (T1 and T2), and an SO2 treatment at 50 mg/L (T3). Five monomeric phenolic compounds were detected in the green tea extract used for the experiment, and their concentrations ranged in the order (-)-epigallocatechin gallate > (-)-epigallocatechin > (-)-epicatechin > (-)-epicatechin gallate > gallic acid. At the studied addition rates, these green tea-derived phenolic compounds contributed to ∼70% of the antioxidant capacity (ABTS), ∼71% of the total phenolic index (TPI), and âˆ¼ 84% of tannin concentration (MCPT) of the extract dissolved in a model wine solution. Among wine treatments, T1 and T2 significantly increased the wine's colour absorbance at 420 nm, MCPT, gallic acid and total monomeric phenolic content. TPI and ABTS were significantly higher in wines with preservatives (i.e., T2 > T1 â‰… T3 > C, p < 0.05). These variations were observed both two weeks after the treatments and again after five months of wine aging. Additionally, an accelerated browning test and a quantitative sensory analysis of wine colour and mouthfeel attributes were performed after 5 months of wine aging. When exposed to excessive oxygen and high temperature (50 °C), T1 and T2 exhibited ∼29% and 24% higher browning capacity than the control, whereas T3 reduced the wine's browning capacity by ∼20%. Nonetheless, the results from sensory analysis did not show significant variations between the treatments. Thus, using green tea extract to replace SO2 at wine bottling appears to be a viable option, without inducing a negative impact on the perceptible colour and mouthfeel attributes of Sauvignon Blanc wine.

Rhubarb powder: Potential uses as a functional bread ingredient.

As a traditional staple food, bread lacks several nutrients such as fiber and minerals. In this study, the possibilities of using rhubarb powder to enrich wheat bread were investigated. Rhubarb powder was replaced with wheat flour at the ratios of 0%, 4%, 8%, and 12%. In order to reveal effects of rhubarb powder on quality properties of bread, color, moisture, total protein, fat content, antioxidant activity, textural, and sensory analysis were conducted. As the rhubarb powder ratio increased, the fiber (10.60 ± 0.55), ash (4.34 ± 0.13), and fat content (2.17 ± 0.55) of bread samples increased significantly (p < 0.05). Antioxidant activity (19.61% ± 0.53%) and total phenolic contents (916.38 ± 2.69) of bread samples also increased significantly (p < 0.05). The colors of the enriched breads were relatively dark. The breads containing 12% rhubarb powder had the highest ash content (4.34 ± 0.13). The samples containing 4% rhubarb powder took the highest sensory scores from the sensory panel in terms of odor, flavor, and overall impression. However, as the ratio of rhubarb powder increased, the sensory values of bread samples decreased. According to the results of this study, rhubarb powder could be used up to 4% to produce acceptable breads in terms of sensory properties with improved nutritional quality.