Biochemical characterization of enzymatic browning in selected apple genotypes

2007 ◽  
Vol 87 (5) ◽  
pp. 1067-1074 ◽  
Author(s):  
A. P. K. Joshi ◽  
H. P. V. Rupasinghe ◽  
N. L. Pitts ◽  
S. Khanizadeh

Enzymatic browning in apples (Malus × domestica Borkh.) caused by polyphenol oxidases (PPO) is the major factor responsible for the deterioration of quality in processed apple products such as juice, fresh-cut slices, and chips. Selected apple genotypes with a range of low post-cut enzymatic browning were investigated to understand the biochemical mechanisms leading to enzymatic browning. Post-cut enzymatic browning, polyphenolic profiles using LC-MS/MS, PPO activity, vitamin C, total antioxidant capacity using the Ferric Reducing Antioxidant Power (FRAP) and the Oxygen Radical Absorbance Capacity (ORAC), and elemental composition were determined in two recently released cultivars [Eden™(also known as SJCA38R6A74) and SuperMac], and one new advanced line (SJCA16) and compared with two commercial cultivars (Empire and Cortland). Eden™ exhibited the least post-cut enzymatic browning as estimated by Whiteness Index. SJCA16 possessed a characteristic yellowish flesh color. Whiteness Index (WI) values were inversely related to chlorogenic acid, catechin and epicatechin contents present in apple slices. Vitamin C content showed a strong positive correlation with WI. Among the mineral elements, the content of copper had a strong positive correlation with PPO activity. Key words: Apple genotypes, enzymatic browning, polyphenoloxidase, polyphenolics, Whiteness Index, total antioxidant capacity

2020 ◽  
Author(s):  
Marzieh Heydari ◽  
Mehdi Shayanfar ◽  
Giuve Sharifi ◽  
Parvane Saneei ◽  
Omid Sadeghi ◽  
...  

Abstract Background: Dietary total antioxidant capacity (TAC) has been investigated in relation to different types of cancer. However, data on the link between dietary TAC and glioma are scarce and conflicting. We assessed the relation between dietary TAC and risk of glioma among Iranian adults. Methods: This investigation was a hospital-based case-control study that was done in Tehran between November 2009 and September 2011. Cases were individuals with pathologically confirmed glioma that were diagnosed during the last month (n=128). Controls were individuals, aged between 20 and 75 years, who were hospitalized or were outpatients referred to other wards of the same hospitals (n=256). Usual dietary intakes of participants during the preceding year were examined using a food frequency questionnaire. Data on dietary TAC from foods was gathered from published databases that provided the antioxidant capacity for each food item, measured by ferric reducing antioxidant power (FRAP). Results: Mean age of study participants in case and control groups was 43.4 and 42.7 y, respectively. Compared with participants in the lowest quartile, those in the highest quartile of dietary TAC had a lower odds of glioma (OR: 0.28, 95% CI: 0.15-0.45). This association was strengthened when potential confounders were taken into account (OR: 0.13; 95% CI: 0.05-0.35). Such inverse association was also seen for men (OR: 0.05, 95% CI: 0.01-0.19), but not for women. Furthermore, significant inverse associations were seen between dietary intakes of vitamin C (OR for Q4 vs. Q1: 0.14, 95% CI: 0.05-0.36; P-trend<0.01), vitamin B6 (OR for Q4 vs. Q1: 0.35, 95% CI: 0.13-0.97; P-trend=0.02) and β-carotene (OR for Q3 vs. Q1: 0.43, 95% CI: 0.19-0.98; P-trend=0.57) and glioma, after controlling for potential covariates. Conclusion: We found that dietary TAC as well as dietary intake of vitamin C, vitamin B6 and β-carotene was inversely associated with odds of glioma in Iranian adults.


2019 ◽  
Vol 886 ◽  
pp. 46-51
Author(s):  
Techaoei Surachai ◽  
Jarmkom Khemjira ◽  
Khobjai Warachate

The main objective aimed to compare in vitro antioxidant power of different recipes of Thai herbal teas including of Tatirot, Krajeab, Kamfoi, and Kesorn Bua. The ferric reducing/antioxidant power (FRAP) assay was used to measure the total antioxidant power of freshly brewed tea. Results showed that different Thai tea recipes had slightly different in vitro antioxidant power. The herbal teas recipe was expressed as µM of antioxidant power/g of dried Thai tea recipes. Values ranges as 555.62±0.77-908.43±0.69 µM/1g of Thai herbal tea, especially Krajeab tea showed strongly antioxidant of 908.43±0.69 µM/1g of tea when compared with other samples. Therefore, it has confirmed that the antioxidant power of Thai herbal tea recipes is considerably intermediate activity than vitamin C


2021 ◽  
Vol 2 (5) ◽  
pp. 6608-6618
Author(s):  
Eva Coronel ◽  
Silvia Caballero ◽  
Gabriela Gonzalez ◽  
Miho Sunguino ◽  
Laura Mereles

Los frutos de Anisocapparis speciosa son nativas de la Ecoregión del Gran Chaco, crecen de manera silvestre en todo este territorio, su pulpa y semillas son comestibles y muy apreciadas por las poblaciones indígenas que lo habitan, además de otros usos con propiedades medicinales atribuidas por conocimientos etnobotánicos, pero no se tienen datos sobre la composición de estos frutos regionales y sus potenciales aplicaciones. El objetivo del presente trabajo fue evaluar la composición de la pulpa y semillas de frutos en estado maduro, y el potencial antioxidante en diferentes estadíos de madurez. La composición proximal, el contenido de minerales, vitamina C y solidos solubles se realizaron según metodologías oficiales de la AOAC.  Los fenoles totales se determinaron por el método de Folin Ciocalteau y la capacidad antioxidante total por medio de la inhibición del radical ABTS. Los componentes mayoritarios en pulpa y semillas fueron carhobidratos y fibra alimentaria. La pulpa madura posee un buen contenido de vitamina C (20 mg/100g). El contenido de fenoles y capacidad antioxidante total fue mayor en la pulpa que en la semillas en estados inmaduros. Los frutos de Anisocapparis speciosa pueden representar una buena fuente de carbohidratos, fibra alimentaria, Mg y vitamina C en la dieta. La pulpa y semillas son fuentes de antioxidantes naturales. Estudios futuros sobre métodos postcosecha, almacenamiento y procesamiento serán necesarios para potenciar su uso y re-valorización en el marco de la Seguridad alimentaria en la población regional.   The native Anisocapparis speciosa fruits from Gran Chaco Ecoregion, they grow wild throughout this territory, their edible pulp and seeds are highly appreciated by the indigenous populations that inhabit it, in addition to other uses with medicinal properties attributed by ethnobotanicals knowledge, but there are no data on the composition of these regional fruits and their potential applications. The aims of the present work were to analyze the pulp and seeds composition of fruits in the ripe state, and the antioxidant potential in different stages of maturity. The proximal composition, minerals content, vitamin C and soluble solids were carried out according to official AOAC methodologies. The total phenolics compounds (TPC) by the Folin Ciocalteau method and the total antioxidant capacity by means of the inhibition of the radical ABTS were evaluated. The main components in pulp and seeds were carbohydrates and dietary fiber. The ripe pulp has a good content of vitamin C (20 mg/100g). The content of TPC and total antioxidant capacity (ABTS radical scavenging) was higher in pulp than in the seeds, in immature stages. The Anisocapparis speciosa fruits can represent a good source of carbohydrates, dietary fiber, Mg and vitamin C in the diet of regional populations. The pulp and seeds are sources of natural antioxidants. Future studies on post-harvest, storage and processing methods will be necessary to enhance its use and re-valorization within the Food Security framework.  


2017 ◽  
Vol 112 (3) ◽  
pp. 121-128
Author(s):  
Dorota Martysiak-Żurowska ◽  
Małgorzata Puta ◽  
Anna Rodzik ◽  
Edyta Malinowska-Pańczyk

Human milk is rich in polyunsaturated fatty acids, as well as lysozyme, vitamin C and other bioactive compounds. The effect of lyophilization on the content of antioxidants (vitamin C and catalase CAT), bactericidal compounds (lysozyme), total antioxidant capacity (TAC) and lipid peroxidation in human milk was investigated in this study. Samples of mature human milk were collected from five healthy women who gave birth on the scheduled date and without complications. Freeze drying resulted in the removal of 88.2 % of the initial water content from milk. The human milk lyophilizate was readily soluble in water. Lyophilization had no effect on the content of primary (lipid peroxides LP) and secondary (thiobarbituric acid reactive substances TBARS) products of lipid oxidation. Freeze-drying led to a significant decrease in the vitamin C content and TAC values of milk (by 31 % and 16.5 %, respectively). Catalase and lysozyme were resistant to freeze-drying. Lyophilization induced a decrease in lysozyme content (9 %) and catalase activity (11 %) but these changes were not statistically significant. Low-temperature dehydration and rehydration of human milk lyophilizates promote satisfactory retention of biologically active ingredients and prevent the oxidation of human milk lipids. The results of this study indicate that lyophilization can be considered as an effective method for prolonging the shelf life of human milk.


2015 ◽  
Vol 82 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Sema Demirci Çekiç ◽  
Aslı Demir ◽  
Kevser Sözgen Başkan ◽  
Esma Tütem ◽  
Reşat Apak

Most milk-applied antioxidant assays in literature are based on the isolation and quantification of individual antioxidative compounds, whereas total antioxidant capacity (TAC) gives a more holistic picture due to cooperative action of antioxidants. Recently, the cupric reducing antioxidant capacity (CUPRAC) method has been modified to measure the antioxidant capacities of thiol-containing proteins, where the classical ammonium acetate buffer – that may otherwise precipitate proteins– was replaced with concentrated urea buffer (able to expose embedded thiol groups of proteins to oxidative attack) adjusted to pH 7.0. Thus, antioxidant capacity of milk was investigated with two competing TAC assays, namely CUPRAC and ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid))/persulphate, because only these assays were capable of evaluating protein contribution to the observed TAC value. As milk fat caused turbidity, experiments were carried out with skim milk or defatted milk samples. To determine TAC, modified CUPRAC method was applied to whole milk, separated and redissolved protein fractions, and the remaining liquid phase after necessary operations. Both TAC methods were investigated for their dilution sensitivity and antioxidant power assessment of separate milk fractions such as casein and whey. Proteins like β-lactoglobulin and casein (but not simple thiols) exhibited enhanced CUPRAC reactivity with surfactant (SDS) addition. Addition of milk protein fractions to whole skim milk produced significant ‘negative-biased’ deviations (up to −26% relative standard error) from TAC absorbance additivity in the application of the ABTS method, as opposed to that of the CUPRAC method less affected by chemical deviations from Beer's law thereby producing much smaller deviations from additivity (i.e. the property of additivity is valid when the measured TAC of a mixture is equal to the sum of individual antioxidant capacities of its constituents).


2018 ◽  
Vol 115 (10) ◽  
pp. E2403-E2409 ◽  
Author(s):  
Mariza G. Prado Lima ◽  
Helen L. Schimidt ◽  
Alexandre Garcia ◽  
Letícia R. Daré ◽  
Felipe P. Carpes ◽  
...  

Recently, nongenetic animal models to study the onset and development of Alzheimer’s disease (AD) have appeared, such as the intrahippocampal infusion of peptides present in Alzheimer amyloid plaques [i.e., amyloid-β (Aβ)]. Nonpharmacological approaches to AD treatment also have been advanced recently, which involve combinations of behavioral interventions whose specific effects are often difficult to determine. Here we isolate the neuroprotective effects of three of these interventions—environmental enrichment (EE), anaerobic physical exercise (AnPE), and social enrichment (SE)—on Aβ-induced oxidative stress and on impairments in learning and memory induced by Aβ. Wistar rats were submitted to 8 wk of EE, AnPE, or SE, followed by Aβ infusion in the dorsal hippocampus. Short-term memory (STM) and long-term memory (LTM) of object recognition (OR) and social recognition (SR) were evaluated. Biochemical assays determined hippocampal oxidative status: reactive oxygen species, lipid peroxidation by thiobarbituric acid reactive substance (TBARS) test, and total antioxidant capacity by ferric reducing/antioxidant power (FRAP), as well as acetylcholinesterase activity. Aβ infusion resulted in memory deficits and hippocampal oxidative damage. EE and AnPE prevented all memory deficits (STM and LTM of OR and SR) and lipid peroxidation (i.e., TBARS). SE prevented only the SR memory deficits and the decrease of total antioxidant capacity decrease (i.e., FRAP). Traditionally, findings obtained with EE protocols do not allow discrimination of the roles of the three individual factors involved. Here we demonstrate that EE and physical exercise have better neuroprotective effects than SE in memory deficits related to Aβ neurotoxicity in the AD model tested.


2019 ◽  
Vol 13 (3) ◽  
pp. 608-616 ◽  
Author(s):  
Andrew Jones ◽  
Agustín Acquaviva ◽  
Thirada Suktham ◽  
Gary R. Dennis ◽  
R. Andrew Shalliker ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Fatemeh Zovari ◽  
Hadi Parsian ◽  
Ali Bijani ◽  
Ameneh Moslemnezhad ◽  
Atena Shirzad

Objective. In menopause, reduction of estrogen hormone affects oxidative stress process in serum. Oxidative stress in saliva plays a significant role in the pathogenesis of oral diseases. The aim of this study was to investigate the total antioxidant capacity and lipid peroxidation in the serum and saliva of premenopausal and postmenopausal women. Methods. In this case control study, 50 postmenopausal women (case group) and 48 premenopausal women (control group) were selected. The unstimulated whole saliva and serum of the postmenopausal and premenopausal women were collected. The total antioxidant capacity (TAC) of the saliva and serum was measured by ferric reducing antioxidant power (FRAP). Also, malondialdehyde (MDA) was measured by thiobarbituric acid reactive substance (TBARS) method for serum and saliva. Then, the obtained data were analyzed by SPSS 17, whereby Mann–Whitney test and Spearman’s correlation test were used. P < 0.05 was considered statistically significant. Results. The postmenopausal group had significantly lower mean serum TAC and higher mean serum MDA than the control group ( P < 0 < 001 and P < 0.01 , respectively). The mean salivary TAC and MDA, however, did not differ significantly between the case and control group ( P = 0.64 and P = 0.08 , respectively). Conclusion. In postmenopausal women, with elevation of serum MDA and reduction of serum TAC, the extent of serum oxidative stress grows, but MDA and TAC levels of saliva do not change.


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