Antioxidant Capacity Of Samples Research Articles

Pembuatan Tortilla Chips Komposit Kulit Melinjo Kerikil dengan Jagung Terhadap Kualitas Inderawi, Tingkat Kesukaan Masyarakat, Kandungan Protein dan Kapasitas Antioksidan

The purpose of this research is to find out 1) Differences in the quality of sensory quality in terms of taste, color, aroma and texture. 2) The level of community preference. 3) Protein content and antioxidant capacity of tortilla chips different kerikil melinjo peel composites. The research method used is the prerequisite test, One Way Analysis of Variance and continued to Tukey's test if there are differences in sensory quality, the preference test uses descriptive analysis of means and Laboratory test. The results showed that there were differences in sensory quality on the color and aroma indicators of tortilla chips. Preferred test results from composite tortilla chips with kerikil melinjo peel (0%:100%, 50%:50%, 60%:40% and 70%:30%) with values (3,98, 3,86, 4,16 dan 4,03). Laboratory test results of protein content and antioxidant capacity of sample 0%:100% (6.9719%, 16.2665%), sample 50%:50% (6.6989%, 18.3361%), sample 60%:40% (7.1234%, 19.8261%), and sample (184) 70%:30% (7.3761%, 21.6887%). The conclusion is that in terms of the quality of the senses there is a significant difference in the color and aroma indicators of different composite tortilla chips of kerikil melinjo peel. The highest average preference test result is 60%: 40% sample. The highest protein content and the highest antioxidant capacity is a sample 70%:30%.

Determination of Antioxidant, Anti-Alzheimer, Antidiabetic, Antiglaucoma and Antimicrobial Effects of Zivzik Pomegranate (Punica granatum)-A Chemical Profiling by LC-MS/MS.

Zivzik pomegranate (Punica granatum) has recently sparked considerable interest due to its nutritional and antioxidant properties. To evaluate the antioxidant capacities of P. granatum juice, ethanol (EEZP), and water (WEZP) extracts from peel and seed, the antioxidant methods of 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid radical (ABTS•+) scavenging, 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH•) scavenging, Fe3+-2,4,6-tris(2-pyridyl)-S-triazine (TPTZ) reducing, Fe3+ reducing, and Cu2+ reducing methods were used. The antioxidant capacities of samples were compared with the most commonly used synthetic antioxidants, i.e., BHA, BHT, α-tocopherol, and Trolox. In terms of setting an example, the IC50 values of EEZP for ABTS•+ and DPPH• scavenging activities were found to be lower than standards, at 5.9 and 16.1 μg/mL, respectively. The phenolic and flavonoid contents in EEZP peel were 59.7 mg GAE/g and 88.0 mg QE/g, respectively. Inhibition of α-glycosidase, α-amylase, acetylcholinesterase, and human carbonic anhydrase II (hCA II) enzymes was also investigated. EEZP demonstrated IC50 values of 7.3 μg/mL against α-glycosidase, 317.7 μg/mL against α-amylase, 19.7 μg/mL against acetylcholinesterase (AChE), and 106.3 μg/mL against CA II enzymes. A total of 53 phenolic compounds were scanned, and 30 compounds were determined using LC-MS/MS. E. coli and S. aureus bacteria were resistant to all four antibiotics used as standards in hospitals.

Investigation of the effects of bovine collagen peptides and mixed berries on rheological properties and biological activity of egg white-based beverage via central composite design.

Modern consumer expectations have become highly diversified: they want more opportunities to meet diverse family needs (diversity of family members in age, gender, physical activity, etc. ,) and individual health goals with a huge variety of sensorial preferences. Our research is aimed to develop a protein-dense, highly bioactive, lactose- and whey protein-free beverage applying a central composite rotational design (CCRD) with 2 factors. For this purpose, an egg white-based beverage was flavored with mixed berries (factor A) and enriched with bovine collagen peptides (factor B). After suitable sample preparation, the rheological properties were investigated by an Anton Paar MCR 92 rheometer (with CC 27 system, and flow behavior was analyzed with a Herschel-Bulkley (H-B) model). The antioxidant capacity of samples was investigated by Ferric Reducing Antioxidant Power (FRAP) method, the total anthocyanin content was estimated based on a spectrophotometric method, and the total phenolic content was determined by the Folin Ciocalteu method. Our results are figured on response surfaces demonstrating that both factors and their interactions show a positive correlation with the examined parameters. Based on the CCRD, all investigated parameters are significantly influenced by at least one aspect and can be adequately estimated for further product development.

Differentiation of juice of mandarin-like hybrids based on physicochemical characteristics, bioactive compounds, and antioxidant capacity

In this study, samples of mandarin-like hybrids (Clemenvilla, Nadorcott and Ortanique) from two harvesting seasons (2017−2018 and 2018−2019) were analyzed, to evaluate its differences in physicochemical characteristics and nutritional properties and establish the parameters that allow classify these citrus cultivars. Results showed that Clemenvilla juice had the highest concentration of total phenolic and ascorbic acid and are strongly correlated to its higher antioxidant capacity. Flavonoids were higher in Nadorcott samples. Large differences of total carotenoids were observed in juice analyzed. Varieties and harvesting seasons significantly influenced (p < 0.05) the physicochemical properties, bioactive compounds content and antioxidant capacity of samples. The pH, flavonoids, ascorbic acid, DPPH and TEAC values were determined as predictor parameters to classify the groups according to the varieties, concluding that Nadorcott samples were clearly different. The data presented in this research will currently provide information about the physicochemical evaluation of mandarin-like hybrid varieties and their potential as source of bioactive compounds and antioxidant capacity.

Effect of Postharvest UV-C Radiation on Nutritional Quality, Oxidation and Enzymatic Browning of Stored Mature Date

The effect of three doses of UV-C radiation (1, 3 and 6 kJ m−2) on conservation potential after harvest of the Deglet-Nour date for five months of storage at 10 °C was studied. Contents of water, total sugar, carotenoids, proteins, total polyphenols, flavonoids and condensed tannins, as well as browning index, enzyme activities of polyphenoloxidase and peroxidase and antioxidant capacity of samples were monitored during storage using standard methods. Doses 1 and 6 kJ m−2 significantly slowed the water loss of samples until the second month of storage, with 17.68% and 16.02% of loss compared to control (31.45%). In the second month of storage, a significant increase in carotenoids was also observed for doses 1 and 6 kJ m−2, with values of 4.17 and 4.02 mg kg−1 versus the control (3.45 mg kg−1), which resulted in deceleration in carotenoid degradation. A gradual decrease in total sugar content was noted for all samples; it was slower within irradiated ones at the second month, where the slowing down of sugar consumption was significantly favored in the samples irradiated at 1 and 6 kJ m−2, which was marked by decreases of 4.98% and 4.57% versus 8.96% in the control. Protein content of irradiated samples (3 and 6 kJ m−2) increased at the third month, giving 1.70 and 2.41 g kg−1 compared to 1.29 g kg−1 for the control. An important decrease in enzymatic activity of polyphenoloxidase was detected, in addition to a fluctuation in peroxidase during storage. The browning index was lower in the irradiated sample until the fourth month of storage, where the result was more significant. An increase in the content of condensed tannins was detected, especially during the two first months, and while the significant increase in the content of flavonoids was read at the last month, it was detected from the first month for polyphenols. This was more significant for the highest dose, were the content reached 0.537 g kg−1 versus 0.288 g kg−1 in control at the first month. A dose-dependent increase in antiradical activity was noted during the last months of storage, while the increase in iron-reducing power was detected at the first month. UV-C delayed installation of Deglet-Nour browning and enriched it with antioxidants.

Antioxidant capacity and rheological, textural properties of ice cream produced from camel's milk with blueberry

Blueberry was added to ice cream samples produced from camel's milk at different concentrations. The physicochemical, rheological, and sensory properties, total phenolic content (TPC), and antioxidant capacity of samples were investigated. The acidity and hardness values of the samples increased, but total solids, fat, protein, pH, ash, overrun values, and complete meltdown time significantly decreased with increasing concentration of blueberry. The L* and b* values decreased, while a* and H° values increased due to the presence of natural colorants in blueberry. The viscosity and consistency coefficient values of ice cream samples decreased depending on the blueberry concentration, whereas TPC and antioxidant capacity increased. The addition of blueberry did not have any affirmative or negative effect on the sensory properties of samples except for appearance, color, and flavor scores. Consequently, blueberry could be added to the ice cream produced using camel's milk at less than a ratio of 10% to improve its nutritional properties. Novelty impact statement Ice cream made from camel's milk with blueberry is a novel dairy product. It is a functional product due to its high antioxidant activity and total phenolic component. The addition of blueberry does not have a negative effect on the sensory properties of the ice cream. As a result, blueberry and camel's milk could be used in new ice cream formulations to produce a nutritional and functional product.

MATHEMATICAL MODELLING OF HOT AIR DRIED APPLE AND EFFECTS OF VARIETY, SHAPE AND TEMPERATURE ON DRYING BEHAVIOR AND QUALITY CHARACTERISTICS

In this study, drying kinetics and quality characteristics of apple cv. Starking, Gala and Granny Smith circles and squares were studied at two different drying temperatures, 60 °C and 70 °C. Drying times were varied between 85-165 min. Depending on variety, shape and temperature. The falling rate period was observed and drying rate changed depending on the drying parameters. Four mathematical models were fitted to experimental data and Logarithmic model was found to be the best for all the samples. Total phenolic contents and antioxidant capacities of dried apple samples varied in the range of 4.11-8.36 mg GAE/g dry matter and 4536.43-7370.47 mmol AEAC 100/g dry matter, respectively and showed a tendency to increase or decrease after drying depending on the variety and shape interaction. Shape had also significant effect on antioxidant capacities of samples as well as the variety (p&lt;0.05). The results of variance analysis demonstrated that there were significant differences among color values of apple samples dried at 60 ºC and 70 ºC.

Electrochemical Determination of Antioxidant Capacity of Traditional Homemade Fruit Vinegars Produced with Double Spontaneous Fermentation.

In the current study, the antioxidant activity of traditional homemade fruit vinegars (HMV) was estimated by measuring the rate of homogeneous redox reaction with 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS•+) using cyclic voltammetry. The antioxidant capacity of six HMV produced using traditional methods and the physicochemical characterization were measured in different vinegar production steps throughout a double spontaneous fermentation process, i.e., without any addition of yeasts or acetic acid bacteria. Their antioxidant capacity was compared with seven fruit commercial vinegars (ComV). Furthermore, the antioxidant capacity was independently measured with the TEAC (Trolox equivalent antioxidant capacity) assay, aiming at correlating with the electrochemical experimental data. Obtained results from both methods, the electrochemical and TEAC assays, interestingly indicated that all HMV have at least 10 times higher antioxidant activity than ComV. Furthermore, the large range of values for antioxidant capacity in samples of commercial vinegars from apples attested the importance of the raw material quality and technological procedures. The positive correlation between total phenolic content and antioxidant capacity measured by the two type of assays indicated that rose hip homemade vinegar (HMV5) has the highest antioxidant capacity. In contrast, the lowest levels of phenolic compounds and antioxidant capacity were found in apple and persimmon homemade vinegars (HMV1 and HMV6, respectively) which indicated that the type of fruit is crucial towards the production of high-quality vinegars. In this way, the use of traditional processes for the production of fruit vinegars proved to be very promising in terms of producing differentiated vinegars and, concomitantly, reaching high levels of health-promoting antioxidant capacities.

A new sight on soy isoflavones during the whole soy sauce fermentation process by UPLC-MS/MS

Soy sauce fermentation process includes koji-making and moromi fermentation stages, with the moromi stage consisting of solid (okara) and liquid (raw soy sauce) phases. Evolution of soy isoflavones in koji, okara and raw soy sauce samples was analyzed systematically, and the rule regarding the formation of soy isoflavones during the whole fermentation process was firstly figured out. Fifteen kinds of soy isoflavones were detected by UPLC-MS/MS. Following the fermentation process, the soy isoflavones profiles changed dramatically in the initial moromi stage (1 d-15 d). The concentrations of glucosides, malonylglucosides and acetylglucosides decreased and disappeared around at okara-30 d, while the concentrations of aglycones and hydroxyl aglycones increased and attained the peak at 90 d of the moromi stage. Additionally, antioxidant capacities of samples were positively correlated with the concentrations of aglycones and hydroxyl aglycones. Interestingly, in each sample, the antioxidant contribution value of hydroxydaidzein was around 100–500 times higher than that of daidzein, which demonstrated that aglycones, especially hydroxyl aglycones, were the key isoflavones contributed to the antioxidant properties of soy sauce.

Using white spread and compound chocolate as phenolic compound delivering agent: A model study with black carrot extract

This study examined the effect of black carrot extract (BCE), an important anthocyanin source, in the composition of different cocoa products (white spread and compound chocolate) with a factorial design. Water activity, moisture content, color, textural, sensory, melting, and flow behavior properties of the samples were determined. Total phenolic compounds and antioxidant capacity of samples were determined before and after in vitro digestion. Moisture content, particle size, hardness, a*, h°, yield stress, plastic viscosity values increased in compound chocolate samples significantly (p < .05). Particle size, a*, and h° values increased in spread samples, but no significant effect on sensory properties was determined. BCE in compound chocolate caused a decrease in the sensory parameters. The bioaccessibility values for total phenolic compounds and antioxidant activity in both groups were determined as 125.5%–244.4% and 118.6%–255.8%, respectively. These values show BCE may be an important phenolic delivering agent without any intolerable quality character change. Novelty impact statement Black carrot extract (BCE) powder was used as a coloring agent and anthocyanin source. This study is the first study using BCE powder in the spread (SC) and compound chocolate (CC). In vitro bioaccessibility of total phenolic compounds was increased. BCE powder has the potential to improve the visual and functional properties of SC and CC.

Effect of fortification with almond milk on quality characteristics of probiotic yoghurt

In this study, five proportions of reconstituted skim milk to almond milk were prepared and probiotic yoghurt was manufactured using these mixtures. The physicochemical, microbiological, and nutritional properties of probiotic yoghurts were examined. Raising the ratio of the almond milk from 0% to 100% resulted in considerably changes in the rate of pH drop due to lack of its buffering capacity. This also led to a considerable increase in viability of starter bacteria, including probiotics, during cold storage. According to nutritional analyses, all parameters (dry matter, protein, lipid, carbohydrate, ash, and mineral elements) had statistically significant differences in all samples. It was observed that the almond milk ratio had significant effect on total phenolic contents and antioxidant capacity of samples. Practical applications Almond, a nutrient-dense food, contains high quality protein, carbohydrates with low glycemic index, unsaturated fatty acids, vitamins, minerals, dietary fiber, phenolic acids, and flavonoids which are essential nutrients for daily consumption and might be stimulator nutrients for probiotic bacteria. Almond milk could be used to produce yoghurts to increase some functional and health-promoting effects, as well as to develop nutritional properties. Almond milk could be used as a supplement in fortification instead of using synthetic ingredients such as sweeteners, flavorings and antioxidants causing adverse health effects. In addition, almond milk can be used a supplement to manufacture novel fermented dairy products.

Phenolic Compounds and Antioxidant Activity of Local Cultivar of Apple (Malus domestica Borkh) in East of Turkey

Apples, rich in phenolic compounds, are widely grown in abundance and consumed as fruit which reduces the risk of many illnesses. In this study, physico-chemical properties old apple cultivars from east of Turkey were investigated. Identification and quantification of phenolic compounds of freeze dried fresh apple varieties (fruit, pulp and peel) were analysed by using the HPLC method. Total phenolic content and antioxidant capacity of samples was also found in 25.00-11.63 mg GAE/g DW and 49.86-86.12 µmol TE/g DW. The highest antioxidant activity was identified in the peel of the Kara Sakı apple whereas the lowest was identified in the pulp of Ak Sakı. Varieties of apple differ significantly in terms of ferulic acid and hidroxycinnamic acid. (-)-Epicatechin was found in the peel of Kara Sakı apple at the very most and p- coumaric acid was found in the pulp of Kara Sakı at the very least. Hidroxycinnamic acid was identified only in the peel. It is approved to these cultivars show unique long shelf life (unusual for apples) without any storage condition due to the significantly presence of ferulic acid.

Antioxidant capacity and total polyphenol content of Lavandula cultivars at different growing areas in Hungary

Lavandula species are worldwide grown essential oil producing medicinal plants with considerable economic value. Beside volatile oil, lavender also contains different phenolic compounds which have been less widely studied till now. Cultivation of lavender has become widespread in Hungary in the recent years, however, growers have limited knowledge on the productivity of cultivars available. In our research we were aimed to studying the antioxidant capacity and total polyphenol content of samples collected in two growing areas (Dörgicse and Szomód) from flowers of two L. angustifolia (‘Hidcote’, ‘Munstead’) and two L. × intermedia (‘Grosso’, Grappenhall’) varieties, during the full blooming period of 2017. Antioxidant capacity of the samples was determined by FRAP assay (Benzie and Strain, 1996), while total polyphenol content (TPC) was measured by a modified method of Singleton and Rossi (1965). According to our results, varieties of L. × intermedia showed higher values of antioxidant capacity and of total polyphenol content, than those of L. angustifolia cultivars. Among them, both the antioxidant capacity (179.6 mg AAE/g DW) and total polyphenol content values (152.4 mg GAE/g DW) of ’Grosso’ from Dörgicse were the highest. Concerning FRAP values of all the cultivars investigated, larger variability were found in Dörgicse, than in Szomód. Regarding the effect of growing area, each cultivar represented similar FRAP values in Dörgicse and in Szomód, except for ’Grosso’. However, in the case of TPC values, higher variability was observed between the growing areas, especially in the case of ’Grosso’. In the future our studies on lavender polyphenols will be completed with qualitative evaluation of the values obtained by HPLC analysis.

Biochemical Properties and Urease, α-amylase Inhibitory Effects of Ocimum basilicum L. (Reyhan)

With the understanding of the role of antioxidants in preventing degenerative and age-related diseases caused by oxidative stress, and taking into account the multitude of pharmacological applications such as antidiabetic, antifungal, cardioprotection, immunostimulant, interest in plants rich in this respect has increased. Ocimum basilicum L. (purple) is a one-year, fragrant spice herb with its own aroma. In this study, chemical characterization of Ocimum basilicum L. plant was performed and inhibition effects on urease and a-amylase were investigated. Total phenolic content of Ocimum basilicum L. leafs ethanolic and water extracts were 320.08±2.03, 388.15±1.05 mg GAE/100g; total flavonoids were 282.57±1.12, 307.75±0.89 mg QE/100g; antioxidant capacity of samples were 0.46±0.01 and 0.52±0.02 mM Fe+2/mg extract, 0.46±0.01; IC50 values of urease were 18.77±0.22, 20.19±0.15 % and IC50 values of α-amylase were 0.47±0.01, 0.42±0.01 µg/mL, respectively. It is determined that ethanolic extract of leaves is rich in linalool, linolenin, phytol and α-humulene. The datas show that the leaves of the plant may be effective on two important diseases such as Diabetus mellitus and H. pylori.

Physicochemical and bioactive properties of Southern Brazilian Apis mellifera L. honeys

The aim of this study was to evaluate the quality of fifty Apis mellifera L. honey samples from southern Brazil in terms of the physicochemical composition, color characteristics, phenolic content, flavanol content, and antioxidant capacity. All of the physicochemical characteristics (moisture, free acidity, pH, sugars, 5-hydroxymethylfurfural, and diastatic activity) of 40 samples (80%) were within the limits established by the Codex Alimentarius Commission. Ten honey samples showed values outside the limits defined by legislation free acidity, moisture and sucrose content. The color of the samples analyzed was very variable and ranged from extra white to dark amber, according to the Pfund’s scale. The phenolic and flavanol compounds content, as well as the antioxidant capacity of samples, showed significant variation, with the darker samples having the highest values. Correlations between the parameters analyzed were statistically significant (p < 0.05) and, antioxidant capacity seemed to be associated with the total phenolic content and honey color. The results demonstrated the importance of evaluating the physicochemical parameters to best guarantee the consumers’ safety. In addition, these honeys samples, especially the darker, present relevant bioactive properties.

Polifenolni sastav ekotipova višnje maraske (Prunus cerasus Marasca) i njihova stabilnost tijekom skladištenja zamrzavanjem

The present research was undertaken to evaluate the polyphenol content of two Marasca sour cherry ecotypes (Recta and Brač 2) grown in two areas in Croatia (Zadar and Split), their stability during freezing storage at -18 °C for six months and contribution to antioxidant capacity (AOC), respectively. Polyphenolic content was assessed by high performance liquid chromatography (HPLC UV/VIS PDA) and anthocyanins (ANT), hydroxycinnamic acids (HCA), flavonol glycosides (FG) and flavanols (FLAV) were determined. ANT dominated in fresh and frozen cherry ecotypes (321.90 – 774.61 mg/100 g dm) and cyanidin-3- glucosylrutinoside (CYGR) was present in the highest concentration (223.22 – 501.04 mg/100 g dm). The contents of other phenolics were considerably lower compared to ANT: HCA=40.72 – 86.28 mg/100 g dm, FG=22.34 – 41.03 mg/100 g dm and FLAV=0.16 – 0.59 mg/100 g dm, where major compounds presented in HCA were p-coumaric and neochlorogenic acids, in FG quercetin-3-glucoside and in FLAV catehin. Furthermore, statistical analysis showed that all sour cherry samples significantly differed according to the ANT, HCA, FG and FLAV content (p≤0.01). Generally, ecotype Recta and Zadar growing area had higher polyphenolic content. Freezing storage caused decrease of almost all polyphenolic groups, particularly ANT (16 – 30 %) and HCA (26 – 36 %) while better stability of FG (10.5 – 20 %) and higher variation of FLAV content was observed. For determination of AOC three methods (DPPH, FRAP, ABTS) were used and the AOC was as follows: DPPH=3.284 – 6.38 mmol TE/100 g dm, FRAP=7.18 - 18 mmol TE/100 g dm and ABTS=73.16 - 119.93 mmol TE/100 g dm. The results indicate higher AOC in samples of Brač 2 ecotype from Zadar growing area.

Determination of microbiological contamination, antibacterial and antioxidant activities of natural plant hazelnut (Corylus avellana L.) pollen

The aim of our study is to determine microbial contamination, antibacterial and antioxidant activities of 14 pollen samples of Corylus avellana collected from different locations in Slovakia. Microbiological analysis was carried out in two steps: microbiological assays and studies of antibacterial activity of pollen extracts. The antimicrobial properties of pollen extracts were carried out with the disc-diffusion method. Methanol (70%), ethanol (70%) and distilled water were used for pollen extracts. Five strains of bacteria such as gram-negative (Salmonella enterica subsp. enterica CCM 3807, Escherichia coli CCM 2024, and Yersinia enterocolitica CCM 5671) and gram-positive (Staphylococcus aureus CCM 2461 and Bacillus thuringiensis CCM 19T) were tested. Antioxidant activity of pollen extracts was determined by the DPPH method. Bacterial analysis includes the determination of the total bacterial count ranged from 4.08 to 4.61 log CFU g−1, mesophilic aerobic bacteria ranged from 3.40 to 4.89 log CFU g−1, mesophilic anaerobic bacteria ranged from 3.20 to 4.52 log CFU g−1, coliform bacteria ranged from 3.30 to 4.55 log CFU g−1, yeasts and filamentous fungi ranged from 3.00 to 3.56 log CFU g−1. Microscopic filamentous fungi Aspergillus spp., Alternaria spp., Penicillium spp., Cladosporium spp., Rhizopus spp., and Paecylomyces spp. were isolated from hazelnut pollen. Yersinia enterocolitica was the most sensitive strain among ethanolic and methanolic pollen hazelnut extracts. Staphylococcus aureus was the most sensitive strain against aqueous hazelnut pollen extracts. We determined the following sensitivity against ethanol pollen extracts respectively: Yersinia enterocolitica > Salmonella enterica > Staphylococcus aureus > Bacillus thuringiensis > Escherichia coli. Methanol pollen extracts had shown following sensitivity: Yersinia enterocolitica > Salmonella enterica > Escherichia coli > Staphylococcus aureus > Bacillus thuringiensis. Aqueous extracts had shown the following sensitivity: Staphylococcus aureus > Salmonella enterica > Escherichia coli > Bacillus thuringiensis > Yersinia enterocolitica. Hazelnut pollen extracts have over 82% antioxidant capacity in samples from non-urban zones. An elevated level of antioxidant potential in the pollen is determined by its biological properties conditioned by biologically active substances. DPPH method allowed characterizing pollen as a source of antioxidants.

Effects of high-humidity hot air impingement blanching (HHAIB) pretreatment on the change of antioxidant capacity, the degradation kinetics of red pigment, ascorbic acid in dehydrated red peppers during storage

Effect of high-humidity hot air impingement blanching on photochemical degradation kinetics (red pigments and ascorbic acid) and antioxidant capacity changes (2,2-diphenyl-1-picrylhydracyl, DPPH and total antioxidant capacity) of red pepper during 6-month storage at ambient temperature in dark was investigated. Ultrastructure of raw and blanched samples was also observed using a transmission electron microscope (TEM). Blanching followed by drying resulted in 63–85% and 33–59% reduction in red pigment and ascorbic acid content, respectively. The antioxidant capacity of samples was found to increase after drying. After 6-month storage, further breakdown of red pigment and ascorbic acid was observed. The red pigment degradation followed the first-order reaction kinetics; untreated samples displayed the most red pigment loss, while the Weibull model described well the ascorbic acid degradation kinetics. Ultrastructure observations explained why over-blanching can cause serious phytochemical degradation. The current findings indicate proper blanching pretreatment prevents phytochemicals degradation of dried pepper during storage.

Variability in Saponin Content, Cancer Antiproliferative Activity and Physicochemical Properties of Concentrated Agave Sap.

Concentrated agave sap (CAS) has gained popularity as an unrefined sweetener. It is obtained by boiling "aguamiel" that contains phytochemicals with diverse bioactivities. Saponins have been the most widely studied agave phytochemicals due to their cancer antiproliferative effect but their concentration may vary due to maturity of the agave plant and collection site. In this study, 18 CAS samples produced in different states of Mexico were analyzed using multivariate methods to determine which physicochemical or phytochemical parameters were responsible for variation. Additionally, extracts with different saponin profiles were tested to determine possible correlations with antiproliferative activity. Total soluble solids, pH, and water activity were similar to those reported for other agave sweeteners. Antioxidant capacity of samples was correlated to browning index. Eleven steroidal saponins were found in CAS samples and they were the main source of variability. Magueyoside B, a kammogenin tetraglycoside, was the most abundant saponin in all samples. With respect to bioactivity, multivariate analysis indicated that magueyoside B and a gentrogenin tetraglycoside were compounds strongly related with bioactivity. CAS from Hidalgo, Puebla, and Veracruz had higher concentration of magueyoside B than from the other kamogenin tetraglycoside found in the samples from other Mexican states. These results could be used as a first approach to characterize and standardize CAS to validate the potential health benefits derived from its consumption.

Effect of malting on antioxidant capacity and vitamin E content in different barley genotypes

Unprocessed barley is known to contain relatively high levels of antioxidants, which play a critical role in human health and the preservation of food and drink products. However, there are limited data on how the antioxidant levels in barley are affected by malting, and whether the level of antioxidants in the processed malt differs between barley varieties. This study aimed to determine the levels of individual vitamin E isomers, total vitamin E content and total antioxidant capacity before, during and after malting in 12 covered and two hulless barley genotypes. Vitamin E content and antioxidant capacity were determined by high-performance liquid chromatography (HPLC) and ability to scavenge DPPH radicals, respectively. The vitamin E content of most genotypes was reduced after steeping, germination and kilning compared with the unprocessed samples. However, the antioxidant capacity in the malt was higher than in the unprocessed samples for the majority of the genotypes. While there was variation in the percentage change in antioxidant capacity between varieties, the antioxidant capacity of samples after malting was directly correlated with their antioxidant capacity before processing (r=0.9, n=14, p<0.05). These results indicate that barley varieties that have higher antioxidant capacity at harvest retain their antioxidants after malting. Thus, these varieties are likely to be the most suitable for producing malts with the added health benefits and anti-spoiling properties associated with greater antioxidant content.