Lipophilic Antioxidant Capacity Research Articles

Augmenting apricot fruit quality and prolonging storage life via modulating ethylene metabolism and antioxidants with 1-(3-phenyl-propyl) cyclopropene and psyllium treatments

ABSTRACT Apricot fruit are characterised by limited post-harvest storability, this study aimed to evaluate the effectiveness and the interplay between psyllium treatment as a coating application method and 1-(3-phenyl-propyl) cyclopropene (1-PCP) as an ethylene inhibitor in enhancing the storability of apricot fruit during storage at 3°C and 90% relative humidity for 32 d. All treatments impacted fruit quality and storability in ‘Canino’ apricots. The combined application of both compounds led to a substantial reduction in fruit decay rate, weight loss, malondialdehyde content, and H2O2 levels. Furthermore, it contributed to improved fruit colouration and TSS content. Both psyllium and 1-PCP treatments, whether applied individually or in combination, notably reduced respiration rates, ethylene production, and the activity of key enzymes involved in ethylene biosynthesis (ACC-synthase and ACC-oxidase) when compared to the control group. Moreover, these treatments reduced oxidative stress, by affecting phenolic content, flavonoids, and antioxidant levels (both hydrophilic and lipophilic antioxidant capacity). Additionally, these treatments regulated related enzymes activities such as catalase, peroxidase, superoxide dismutase, and phenylalanine-ammonia lyase. Hence, it is recommended to utilise psyllium and 1-PCP to enhance the storability of apricot fruit while maintaining their overall quality.

Fruits from tomato carotenoid mutants have altered susceptibility to grey mold

The necrotrophic fungus Botritys cinerea takes advantage of the oxidative burst to facilitate tissue infection, leading to substantial losses during tomato postharvest. Tomato fruit is a source of carotenoids, pigments with a wide variety of isomeric configurations that determine their antioxidant capacity. Here, fruit susceptibility to B. cinerea was assessed in Micro-Tom Near Isogenic lines harboring mutations that alter the profile of carotenoids. Wound-inoculated fruit of the mutants Delta carotene (Del) and tangerine (t), which show large variety of carotenoids rather than the major accumulation of trans-lycopene, were less susceptible to the pathogen. Differences in susceptibility between the mutants were only observed in ripe fruit, after the formation of carotenoids, and they were associated with attenuation of damage caused by reactive oxygen species. The greater variety of carotenoid isomers, which in turn contributed to the greater lipophilic antioxidant capacity of fruit, was associated with the less susceptible mutants, Del and t. Together, our data reveals a potential activity of carotenoids in fruit defense, in addition to the well-known and widespread ecological role as attractors of seed dispersers.

Functional sugar-free chewing gum infused with spices bolsters antioxidant capacity and phenolic content of saliva

Oral and vascular diseases are seemingly disparate conditions, yet individuals with poor oral health are at increased risk for cardiovascular events. Spice-derived bioactive polyphenols with antioxidant functionality may attenuate mechanisms linking the diseases, namely oxidative stress and inflammation. Acknowledging that novel approaches to increase antioxidant intake are warranted, the purpose of this study was to evaluate the influence of two functional sugar-free gums infused with spices on antioxidant capacity and phenolic content of saliva using the oxygen radical absorbance capacity and Folin-Ciocalteu assays, respectively. Unstimulated followed by stimulated saliva was collected according to a validated method across a prescribed five minute chewing period. Both gums significantly increased hydrophilic, lipophilic, and total antioxidant capacity of saliva (p < 0.05) yet to varying extents. Phenolic content of saliva was significantly higher (p < 0.001) post-chew for both gums. Results suggest spices infused into sugar-free chewing gum bolster the antioxidant capacity of saliva, thereby promoting oral health. Research evaluating the sublingual absorption of spice-derived antioxidants in functional gums and their influence on systemic oxidative stress is warranted.

Physiological responses, nutritional quality and aroma volatiles of the red-fleshed kirkwood navel and ruby valencia oranges during postharvest cold storage

This study evaluates the postharvest performance and responses of the red-fleshed Kirkwood Navel and Ruby Valencia oranges to cold storage (28 d at 2 °C) and shelf-life (5 d at 20 °C) in comparison with the standard varieties Washington Navel and Valencia late, respectively. Fruit of Kirkwood and Ruby exhibited lower chilling injury than the reference varieties while maintained similar weight loss and peel firmness. Moreover, the large concentration and the original composition of carotenoids in the pulp of Kirkwood and Ruby was preserved during the postharvest storage. Similarly, the content of vitamin C, phenolics and flavonoids, and the higher lipophilic antioxidant capacity and the capacity to quench singlet oxygen of the red-fleshed oranges remained unaltered after the whole storage period. The content of other compounds as tocopherols and sugars increased at the end of the storage period in fruit of the red-fleshed varieties. Monoterpenes, norisoprenoids, ethanol, aldehydes and ethyl esters were the compounds that exhibited the major changes during the postharvest storage, especially in the red-fleshed varieties. The profile of volatile compounds of Kirkwood and Ruby fruit was characterized by higher levels of norisoprenoids, monoterpenes, long-chain aldehydes, and variable content of aliphatic esters compared to the reference varieties. Altogether, our results indicated that Kirkwood Navel and Ruby Valencia oranges show good postharvest performance and potential for long-term cold storage, ensuring their quality and retaining their enhanced properties and added value to consumers. Data availabilityAll data are available in the manuscript or supplementary materials.

Diets Containing Shiitake Mushroom Reduce Serum Lipids and Serum Lipophilic Antioxidant Capacity in Rats

Background: We previously reported that dietary intake of shiitake mushroom (SM; Lentinus edodes) decreased serum concentrations of polar lipids in male rats.Objective: This study evaluated the dietary effects of SM on serum cholesterol–related and serum antioxidant indexes in rats of both sexes.Methods: Sprague-Dawley rats [38 dams and their offspring (20 males and 20 females/diet)] were fed diets containing 0 (control), 1%, 4%, or 10% (wt:wt) SM powder from gestation day 4 through to postnatal day (PND) 126. Biochemical indexes were monitored during the midgrowth phase (PNDs 50–66).Results: The food consumption by offspring fed the control diet and diets supplemented with SM was not different when measured on PND 65. However, the 4% and 10% SM diets resulted in male rats with 7% lower body weights than those of the other 2 groups on PND 66. SM consumption dose-dependently decreased the concentrations of lipidemia-related factors in sera, irrespective of sex. At PND 50, serum concentrations of total cholesterol, HDL cholesterol, and non-HDL cholesterol in SM-fed male and female rats were generally lower (3–27%) than those in the corresponding control groups. Consumption of the 10% SM diet resulted in significantly decreased (55%) serum triglyceride concentrations relative to the control groups for both sexes. The 10% SM diet elicited a 62% reduction of serum leptin concentrations in females but not in males, and this same diet increased serum insulin (137%) and decreased serum glucose (15%) in males compared with controls. Serum lipophilic antioxidant capacity in males and females fed SM diets was generally lower (31–86%) than that in the control groups.Conclusion: SM decreased the concentrations of lipidemia-related factors in rat sera irrespective of sex. The SM-elicited reduction of lipophilic antioxidant capacity irrespective of sex may reflect a lower pro-oxidative state and, hence, improved metabolic profile.

Juices and By-Products of Red-Fleshed Sweet Oranges: Assessment of Bioactive and Nutritional Compounds.

The content of nutrients and bioactive compounds, and antioxidant capacity were assessed in the juices from two red-fleshed oranges, Cara Cara and Kirkwood, and compared with that of a standard Navel orange. Two juice extraction procedures, hand-squeezing and industrial, and two treatments, pasteurization (85 °C/30 s) and high-pressure homogenization (HPH, 150 MPa/55 °C/1 min), were evaluated. For most of the nutrients and bioactive compounds, the hand and industrial juice squeezing rendered similar extraction efficiency. Individual composition of carotenoids in the juices were differentially affected by the extraction procedure and the treatments, but the red-fleshed orange juices contained between 3- to 6-times higher total carotenoids than the standard Navel juices, being phytoene and phytofluene the main carotenoids. The industrial and treated juices of both red-fleshed oranges contained 20-30% higher amounts of tocopherols but about 20% lower levels of vitamin C than Navel juices. Navel juices exhibited higher hydrophilic antioxidant capacity, while the red-fleshed orange juices showed an improved lipophilic antioxidant capacity. The main distinctive characteristic of the industrial juice by-product of the red-fleshed oranges was a higher content of carotenoids (×10) and singlet oxygen antioxidant capacity (×1.5-2) than the Navel by-product.

Bioactive Compounds, Nutritional Quality and Antioxidant Capacity of the Red-Fleshed Kirkwood Navel and Ruby Valencia Oranges.

Kirkwood Navel and Ruby Valencia are two spontaneous bud-mutations of the ordinary Washington Navel and Valencia late oranges characterized by the red coloration of their flesh. The purpose of this study was to analyze the physiological features, internal fruit quality, contents of relevant bioactive compounds and antioxidant capacity in the pulps of the red-fleshed fruits compared with the ordinary oranges during late development and maturation. In general, the content of sugars, organic acids, vitamin C, tocopherols, total phenolics and flavonoids, the hydrophilic antioxidant capacity and their changes during maturation were similar in the red-fleshed oranges and in the corresponding blond oranges. However, the mature Ruby fruits contained lower concentrations of sugars, malic and succinic acid and higher levels of citric acid than the ordinary Valencia. The major difference between the pulps of the Kirkwood and Ruby oranges and those of the ordinary oranges was the higher lipophilic antioxidant capacity and SOAC (singlet oxygen absorption capacity) of the former. Together, the high and unique content and composition of carotenoids in Kirkwood and Ruby may contribute to an enhanced antioxidant capacity without any detrimental effects on other fruit-quality attributes, making these varieties good sources of phytochemicals for the fresh-fruit and juice-processing citrus industries.

High pressure processing and heat sterilization of kale: Impact on extractability, antioxidant capacity and storability of carotenoids and vitamin E

AbstractFood process engineering represents a rapidly evolving discipline traditionally focussing on thermal treatments including objectives such as preservation and stabilization. Innovative and gentle preservation techniques such as high‐pressure processing (HPP) may potentially improve or replace conventional methods by enhancing nutritional and health aspects, flavor and taste, sustainability, and more consumer‐targeted, minimally processed food items. As information about the impact of HPP (600 MPa, 5–40 min) on lipophilic food ingredients (e.g., carotenoids, vitamin E) in kale is limited, a comparison to heat sterilization (20 min, 121°C) may result in new insights related to lipophilic, antioxidant capacity (L‐AOC), extractability and storage stability (8 weeks, 5°C). HPP of chopped kale resulted in significantly increased (p &lt; 0.05) total carotenoid and chlorophyll contents in contrast to declined concentrations of vitamin E. Significantly decreased extractabilities were observed for total carotenoids and chlorophylls in heat sterilized kale, showing no significant change (p &gt; 0.05) in vitamin E content. Moreover, 2 months of storage of HP‐treated kale resulted in a major loss of vitamin E and total carotenoid contents compared to thermally treated samples. Elevated α‐tocopherol equivalent antioxidant capacities (αTEAC) and lipophilic oxygen radical antioxidant capacities (L‐ORAC) correlated with an increased pressure holding time.

Evaluating the impact of feeding dried distillers grains with solubles on Boer goat growth performance, meat color stability, and antioxidant capacity.

A total of 72 male Boer goat kids (21.7 ± 0.5 kg) were fed for 21 d with 3 kids per pen and 12 pens per treatment. Dietary treatments were: 0% inclusion of dried distillers grains with solubles (DDGS; 0% DDGS) or 33% DDGS inclusion (33% DDGS) and were provided ad libitum. Goats and feeders were weighed weekly to collect body weights (BW) and determine feed disappearance in order to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). At the conclusion of the feeding study, a subset (n = 30; 2–3 goats from each pen representing six6 pens per treatment) of goats were harvested, carcasses evaluated, and loins were fabricated into 2.54 cm chops. Goat chop discoloration was evaluated by trained panelists and measured for L*, a*, and b* values on days 0, 4, 7, and 10 under retail display conditions. Samples were collected and analyzed for lipid oxidation, fatty acid profile, and hydrophilic and lipophilic antioxidant capacity. No evidence of differences was observed for final BW, ADFI, G:F, and carcass characteristics (P > 0.05). However, goats fed the 0% DDGS diet had greater ADG compared with those fed a diet containing 33% DDGS (P = 0.05). Overall, visual evaluation of discoloration, L*, a*, and b* as well as lipid oxidation data confirmed that feeding 33% DDGS to goats had no effect on goat chop discoloration and lipid oxidation (P > 0.10). However, all chops demonstrated a display effect, which they increased in visual discoloration and lipid oxidation and decreased in a* and b* values (P < 0.01) over the entirety of the 10-d period of retail display, regardless of the dietary treatments. As expected, feeding 33% DDGS to goats decreased relative percentage of multiple and total monounsaturated fatty acids, but increased relative percentage of multiple and total polyunsaturated fatty acids (PUFA; P < 0.05). The antioxidant capacity measurements showed no treatment difference in the hydrophilic portion (P > 0.10), but chops from the 33% DDGS treatment had greater lipophilic antioxidant activity compared with the 0% DDGS chops (P < 0.05). In conclusion, including 33% DDGS to the diet may negatively impact goat growth performance, but did not impact any carcass characteristics. Feeding a diet with 33% DDGS resulted in an increase in the PUFA content of goat chops but did not appear to impact meat color or lipid oxidation. The supposed negative consequence from increased PUFA is likely counterbalanced by the increased antioxidant capacity in the lipid component of meat, resulting in no difference in meat shelf-life.

Methyl salicylate affects the lipophilic and hydrophilic antioxidant capacities of apricot by regulating carotenoid biosynthesis and phenolic metabolism

The carotenoid biosynthesis and phenolic metabolism were studied to explain the effect of methyl salicylate (MeSA) on the lipophilic antioxidant capacity (LAC) and hydrophilic antioxidant capacity (HAC) in apricot during postharvest storage. Our results indicated that the HAC of apricot was higher than LAC and mainly responsible for total antioxidant capacity of apricot. Preharvest spraying of MeSA (0.2 mmol L−1) could improve the value of HAC but declined LAC of apricot. The enhanced HAC in MeSA treated apricot was positively related to the increased content of phenolics, especially to (+)-catechin, which was catalyzed by the enzymes related to phenolic metabolism. While, the decline of LAC in apricot treated by MeSA could be attributed to the inhibition of carotenoids accumulation, which was regulated by carotenogenic genes. We concluded that MeSA could affect the lipophilic and hydrophilic antioxidant capacity of apricot by regulating carotenoid biosynthesis and phenolic metabolism.

Enzymatic pre-treatment in cold pressing: Influence on flaxseed, apricot kernel and grape seed oils

A commercial enzyme preparation consisting of pectolytic, cellulotic and hemicellulotic enzymes was applied to the oil extraction by cold pressing from apricot kernel, flaxseed and grape seed. The effects of enzyme pre-treatment varied depending on the different oil seed used as raw material. Although the increase in free fatty acidity can be considered as a negative effect (from 0.37 to 0.52), the decrease in peroxide number and p-anisidine values, increase in oil yield (22.75%), higher levels of total carotenoids and tocopherols, as well as a remarkable increase in phenolic content (x1.68) and radical scavenging effect (including hydrophilic and lipophilic-induced and total antioxidant capacity) showed that the use of enzyme application in the cold pressing of apricot kernel oil would be beneficial. Many of these positive results could not be achieved in the pressing of flaxseed or grape seed oils under the same conditions. A high negative correlation (r=-92.2) was found between p-anisidine value and δ-tocopherol for grapeseed oil. Hydrophilic and lipophilic antioxidant capacity, total phenolics, and total carotenoids negatively correlated well (r values above 80) with peroxide values for apricot seed oil. Correlation results showed that carotenoids play an important role in the oxidative stability of the oils, where it was much more evident for apricot seed oil (r=-97.5).

Evaluation of Hydrophilic and Lipophilic Antioxidant Capacity in Spanish Tomato Paste: Usefulness of Front-Face Total Fluorescence Signal Combined with Parafac

The hydrophilic and lipophilic antioxidant activities due to the main bioactive components present in Spanish tomato paste samples were studied, using standardized and fluorescent methods. After extraction, phenolic antioxidants (Folin-Ciocalteu method) and total antioxidant activity (TEAC assay) were evaluated, examining differences between hydrophilic and lipophilic extracts corresponding to different samples. Total fluorescence spectra of extracts (excitation-emission matrices, EEMs) were recorded in the front-face mode at two different ranges: 210–300 nm/310–390 nm, and 295–350 nm/380–480 nm, for excitation and emission, respectively, in the hydrophilic extracts. In the lipophilic extracts, the first range was 230–283 nm/290–340 nm, while the second range was 315–383 nm/390–500 nm for excitation and emission, respectively. EEMs from a set of 22 samples were analyzed by the second-order multivariate technique Parallel Factor Analysis (PARAFAC). Tentative assignation of the different components to the various fluorophores of tomato was tried, based on literature. Correlation between the antioxidant activity and score values retrieved for different components in PARAFAC model was obtained. The possibility of using EEMs-PARAFAC to evaluate antioxidant activity of hydrophilic and lipophilic compounds in these samples was examined, obtaining good results in accordance with the Folin-Ciocalteu and TEAC assays.

Effect of Fresh Citrus Pulp Supplementation on Animal Performance and Meat Quality of Feedlot Steers.

Simple SummaryThe use of crop, fruit, and vegetable processing co-products for animal feeding has been of increasing interest worldwide to minimize feed waste. Additionally, it has a positive impact from an environmental standpoint being a more efficient use of feed resources. However, the use of many co-products has limitations related to poor palatability for animals and the logistical aspects of product delivery. Citrus pulp is a by-product of the citrus industry presenting a nutritional composition that makes it attractive for use as an ingredient in animal feeding. Previous research has shown that it is feasible to utilize citrus pulp in beef cattle rations. The objective of the present study was to evaluate the effect of the inclusion of fresh citrus pulp in the diet of feedlot steers on animal performance and carcass and meat nutritional properties and quality. The findings of the study showed that fresh citrus pulp may be used as an energy source in rations for feedlot steers as it does not affect animal performance or carcass and meat quality, but, rather, has a positive effect on dry matter intake and a better feed to gain ratio.The use of fruit by-products such as citrus pulp represents a feeding ingredient that deserves to be evaluated as an energy source in animal rations. Thirty-six British breed steers were allotted to one of the three feeding treatments (12 steers/treatment): 0%, 15% and 30% of fresh citrus pulp inclusion in the ration in a randomized complete block design to evaluate animal performance and carcass and meat quality traits. In the present study, the inclusion of fresh citrus pulp up to 30% of the diet did not affect the animal average daily gain (p > 0.05) but steers that were fed the pulp consumed less feed (p < 0.05) and presented a lower feed conversion ratio (p < 0.05) than their counterparts without citrus pulp in their diet. No effect of fresh citrus pulp was observed on carcass and meat quality (p > 0.05). A greater lipophilic antioxidant capacity (p < 0.05) in meat was observed when fresh citrus pulp was offered at 15% of the diet. Fresh citrus pulp used up to 30% as a feed ingredient in feedlot rations does not negatively affect animal performance or meat quality but, rather, has a positive effect on dry matter intake and a better feed conversion ratio.

High-Pressure Processing of Kale: Effects on the Extractability, In Vitro Bioaccessibility of Carotenoids & Vitamin E and the Lipophilic Antioxidant Capacity.

High pressure processing (HPP) represents a non-thermal preservation technique for the gentle treatment of food products. Information about the impact of HPP on lipophilic food ingredients (e.g., carotenoids, vitamin E) is still limited in more complex matrices such as kale. Both the variation of pressure levels (200–600 MPa) and different holding times (5–40 min) served as HPP parameters. Whereas a slightly decreasing solvent extractability mostly correlated with increasing pressure regimes; the extension of holding times resulted in elevated extract concentrations, particularly at high-pressures up to 600 MPa. Surprisingly, slightly increasing bioaccessibility correlated with both elevated pressures and extended holding times, indicating matrix-dependent processes during in vitro digestion, compared to results of extractability. Moreover, the verification of syringe filters for digest filtration resulted in the highest relative recoveries using cellulose acetate and polyvinylidene difluoride membranes. The α-tocopherol equivalent antioxidant capacity (αTEAC) and oxygen radical antioxidant capacity (ORAC) assays of treated kale samples, chopped larger in size, showed increased antioxidant capacities, regarding elevated pressures and extended holding times. Consequently, one may conclude that HPP was confirmed as a gentle treatment technique for lipophilic micronutrients in kale. Nevertheless, it was indicated that sample pre-treatments could affect HP-related processes in food matrices prior to and possibly after HPP.

Effect of high intensity ultrasound on main bioactive compounds, antioxidant capacity and color in orange juice.

Ultrasound is a useful alternative to thermal processing that can be applied to many food products and juices to aid with enzymes and microorganism inactivation and to improve the efficiency of unit operations generally applied in the food industry. The aim of this study was to evaluate the effect of a high-intensity sonication treatment (frequency 20 kHz; intensity 39.4 W/cm2) applied for treatment times from 0 to 105 min on the content of polyphenols, vitamin C, organic acids, and carotenoids, and on the hydrophilic and lipophilic antioxidant capacity and color of orange juice. Treatments were performed in triplicate and data was statistically analyzed. Sonication time did not have a significant effect (P > 0.05) on total polyphenols, total vitamin C, organic acid, and carotenoid contents, lipophilic antioxidant capacity, or juice color. The hydrophilic antioxidant activity and the lutein content increased significantly (P < 0.05) with increased sonication time. These results may be useful as a baseline for the development of sonication treatments that could be used in combination with other traditional and emerging processing approaches to protect the most important bioactive compounds and quality properties of orange juice.

Physicochemical and bioactive compounds at edible ripeness of eleven varieties of avocado (Persea americana) cultivated in the Andean Region of Peru

SummaryThis work aimed evaluating some physicochemical compounds, hydrophilic (H‐AC) and lipophilic (L‐AC) antioxidant capacity of eleven avocado genotypes grown in the Andes. The results show great variability in physical and chemical properties, dry matter (DM) and lipid contents with ranges of 18.4–39.3% and 10.1–23.2%, respectively. All genotypes had high oleic acid content (50.4–69.9%) and a high unsaturated fatty acid/saturated fatty acid ratio (UFA/SFA, from 3.05 to 6.05), while the unsaponifiable fraction contained mainly β‐sitosterol (140.83–235.51 mg/100 g DM) and α‐tocopherol (17.44–71.29 µg/g DM). Total phenolic compounds (TPC), H‐AC and L‐AC ranged from 0.48 to 0.88 mg EAG/g DM, 5.37 to 14.00 and 1.87 to 6.71 μmol ET/g DM, respectively. Although the genotype influences avocado characteristics, climatic conditions in the Andean region seem to be important for the biosynthesis of metabolites of interest and should be considered in future studies.

Development, Feasibility, and Initial Results of a Mindful Eating Intervention: Project Mindful Eating and Exercise (MEE): Feeding the Mind, Body, and Soul

ABSTRACT Background: The aim of this study was to develop a mindful eating intervention and evaluate potential changes in selected outcomes. The Transactional Model of Stress and Coping was used to guide the curriculum development and selection of evaluation measures. Purpose: The purpose of this study was to test the feasibility and acceptability of implementing a behavioral intervention entitled, “Project MEE (Mindful Eating and Exercise): Feeding Your Mind, Body, and Soul.” Methods: Pre-menopausal women, 25–50 years, with a body mass index (BMI) of 25–40 kg/m2 participated in the development of the curriculum (n = 13) and initial testing of the final eight-week intervention (n = 18). Selected measures included the Perceived Stress Scale (PSS), Mindful Eating Questionnaire (MEQ), Eating and Appraisal Due to Emotions and Stress Questionnaire (EADES), BMI, waist circumference, blood pressure, and serum hydrophilic (H-AOX) and lipophilic (L-AOX) antioxidant capacity. Paired t-tests were used to assess for significant changes between baseline and follow-up measures. Results: Although PSS scores improved slightly, MEQ scores (p = .001), stress-related eating scores (p = <0.001), body weight (p = .02), waist circumference (p < .001), systolic blood pressure (p = .05), H-AOX (p = .02), and L-AOX (p < .001) improved significantly. Discussion: Project MEE intervention has the potential to reduce maladaptive coping efforts, such as mindless and stress-related eating, and produce changes in health status. Translation to Health Education Practice: Health educators may want to include mindful eating strategies and use this behavioral theory when designing programs for stress-related eating.

Post-Harvest Use of Ultraviolet Light (UV) and Light Emitting Diode (LED) to Enhance Bioactive Compounds in Refrigerated Tomatoes

Different strategies have been developed to increase the concentration of bioactive compounds in tomatoes during post-harvest, with ultraviolet light (UV) and light emitting diodes (LEDs) being interesting tools. The aim of this study was to evaluate the effect of ultraviolet (UVA at 366 nm and UVC at 254 nm) pre-treatment (1 kJ/m2) and red–blue LED light (25.4 µmol/m2/s) on the concentration of carotenoids, (poly)phenols and hydrophilic/lipophilic antioxidant capacity during 7 days of refrigeration storage of green tomatoes (Solanum lycopersicum L.) cultivar “Raf”. In addition, special attention was paid to quality parameters (weight loss, colour, acidity, soluble solids and ripening index). Tomatoes exposed to LED light at 6 °C for 7 days increased up to three times the total carotenoids content (mainly β-carotene and E-lycopene) compared to tomatoes refrigerated in the dark, while UV treatments alone did not significantly affect the carotenoid content. Besides, exposure to LEDs increased the hydrophilic and lipophilic antioxidant capacity of tomatoes by 30%, without affecting phenolic contents. Thus, LED treatments alone during refrigerated storage fostered ripening and improved the nutritional value of tomatoes, without compromising quality parameters. Further studies must be carried out to evaluate the impact on sensory attributes and consumer acceptance.

Effects of high-temperature cooking on the gamma-aminobutyric acid content and antioxidant capacity of germinated brown rice (Oryza sativa L.)

ABSTRACT Germinated brown rice (GBR) has a high gamma-aminobutyric acid (GABA) content and antioxidant capacity; however, the effects of high-temperature cooking on these characteristics are unclear. We investigated alterations in GABA content, antioxidant capacity, 15 proteinogenic amino acids, TP and reducing sugar content, and color of cooked GBR at 105°C to 135°C and at different times (40 to 90 min) at 105°C. The contents of GABA and 9 proteinogenic amino acids decreased via thermal decomposition with increasing cooking temperatures. The hydrophilic and lipophilic antioxidant capacities (DPPH and L-ORAC) were enhanced at temperatures >125°C. L-ORAC values were strongly associated with the glucose content and L*, a*, and b* values. Additionally, prolonged treatment time decreased the content of 12 amino acids but increased DPPH and L-ORAC. Our results on functional ingredients and activity are useful for both home cooking and manufacturing processes and may lead to the development of better-processed products.

Antioxidant capacity in fruit of Citrus cultivars with marked differences in pulp coloration: Contribution of carotenoids and vitamin C.

The purpose of this study was to evaluate the specific contribution of carotenoids and vitamin C to the lipophilic and hydrophilic antioxidant capacity, respectively, of the pulp of citrus fruits using the genetic diversity in pigmentation and in the carotenoid complement. To this end, six citrus varieties were selected: two mandarins, Clemenules (Citrus clementina) and Nadorcott (C. reticulata); two grapefruits (C. paradisi), Marsh and Star Ruby; and two sweet oranges (C. sinensis), Valencia late and Valencia Ruby. Total carotenoid content and composition in the pulp of fruits were very different, in relation to their color singularities. Valencia Ruby and Nadorcott had the highest carotenoid content, accumulating the former large amounts of linear carotenes (phytoene, phytofluene, and lycopene) and Nadorcott of β-cryptoxanthin. Orange fruits contained the highest amount of vitamin C while in Nadorcott mandarin it was substantially lower. Analysis of antioxidant capacity, evaluated by 2,2'-azino-di-(3-ethylbenzthiazoline sulfonate) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, in the pulp of the different fruit varieties indicated a high and positive correlation between vitamin C content and hydrophilic antioxidant capacity. Nevertheless, a weak correlation was observed between carotenoids content and lipophilic antioxidant capacity in the pulp extracts assayed by ABTS. Overall, vitamin C in the pulp of citrus fruit had an important contribution to the hydrophilic antioxidant capacity, whereas that of carotenoids to lipophilic antioxidant capacity was very variable, being the highest that of Valencia Ruby orange, with large concentrations of lycopene and phytoene, followed by Nadorcott mandarin, with high β-cryptoxanthin content.