The present work was aimed to determine the contents of ascorbic acid and the antioxidant activity of eight types of common fruits commercially available in Addis Ababa, Ethiopia using iodometric ...titration and UV-Vis spectrophotometric methods, respectively. The contents of ascorbic acid were found in the range 15.41 mg/100 g in grapes to 78.01 mg/100 g in papaya. The antioxidant activity was found highest in papaya (89.41) and lowest in water melon (31.28) in mg of ascorbic acid equivalent per 100 g of the edible part of fruit juice. The calibration curve of ascorbic acid was in the range 50 - 3.125 mg/L with R2 = 0.9994. The results also revealed the strong correlation (r = 0.863) between ascorbic acid contents in fruits and their antioxidant activity. Using the optimized conditions, UV-Vis spectrophotometric method with the 2,2-diphenyl-1-picrylhydrazil assay allows determination of antioxidant activity of fruits with limit of detection 0.32 mg/L and limit of quantification 0.96 mg/L. The precision was in the acceptable range (relative standard deviation, RSD < 20%) for determination of ascorbic acid and < 10% for antioxidant activity determination. The recovery of ascorbic acid was between 85% and 113% for selected fruits showing good accuracy of the results.
KEY WORDS: Fruits, Ascorbic acid contents, Antioxidant activity, Free radical scavengers, Iodometric titration, UV-Vis spectrophotometry
Bull. Chem. Soc. Ethiop. 2023, 37(2), 277-288.
DOI: https://dx.doi.org/10.4314/bcse.v37i2.3
Pomegranate juice is a complex mixture of structurally diverse compounds appearing in various concentrations. The composition of the final product depends on several factors, such as the fruit ...variety and the addition of adulterants. Its diverse composition makes pomegranate juice an excellent system for assessing the potential of an analytical method for targeted and untargeted analysis. Here, we tested the ability of 1D and 2D NMR spectroscopy techniques for the targeted and untargeted metabolite analysis of pomegranate juice. The NMR spectra assignment was performed using the novel NOAH sequences and spiking with model compounds. Several metabolites, including sugars, organic acids, and amino acids, were identified and quantified in a rapid and simultaneous manner. Five internal standards were tested, with potassium hydrogen phthalate and dimethylmalonic acid found to be the most appropriate, based on their shorter T 1 relaxation times and spectral simplicity, while MnCl2 was successfully applied as a relaxation agent for the reduction of the experimental time. Among the pulse sequences that were tested for their quantitative potential, the Carr–Purcell–Meiboom–Gill gave the best results. The quantitative, QEC-HSQC experiment was also found to be very promising for mixture analysis. Additionally, the potential of 1D/2D NMR-based untargeted analysis was successfully tested on two cases, namely, differentiation between cultivars and detection of adulteration with apple juice. This study demonstrates the proof of concept for 1D and 2D NMR methods in the targeted and untargeted analysis of pomegranate juice and can be extended to other complex matrices.
Food-drug interactions: focus on fruit juices Petrić, Zvonimir; Žuntar, Irena; Kovačević, Danijela Bursać ...
Arhiv za higijenu rada i toksikologiju,
01/2021, Letnik:
72
Journal Article
Diversity, flexibility, easy accessibility, broad continuing acceptance in developing countries and increasing popularity in developed countries, relative low cost, low levels of technological input, ...relative low side effects, and growing economic importance are some of the positive features of traditional medicine. In rural India, traditional medicine continues to be the only available form of care. Many communities continue to treat patients using their old methods, unaffected by contemporary medical advancements. Due to their accessibility, affordability, and ease of use, tribal tribes prefer to utilize and consult their own traditional healers. These are likewise thought to be highly effective and without any adverse effects. This paper aims to identify various traditional medicines used for treating illness and infirmities, by taking accounts from the residents of Chungtlang village, Mamit District, Mizoram. The objective here lies in discovering traditional knowledge of medicinal plants and their uses for various infirmities.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK, VSZLJ
•In this study, e-Nose and e-Tongue have been built for 11-juices characterisation.•No clear juice discrimination can be drawn when we used the two instruments singly.•Electronic sensing systems have ...been combined by low-level of abstraction data fusion.•Rapid pattern screening of the juices has been achieved by the data fusion approach.
There are many important challenges related to food security analysis by application of chemical and electrochemical sensors. One critical parameter is the development of reliable tools, capable of performing an overall sensory analysis. In these systems, as much information as possible is required in relation to smell, taste and colour. Here, we investigated the possibility of using a multisensor data fusion approach, which combines an e-Nose and an e-Tongue, adept in generating combined aroma and taste profiles. In order to shed light on this concept, classification of various Tunisian fruit juices using a low-level of abstraction data fusion technique was attempted. Five tin oxide-based Taguchi Gas Sensors were applied in the e-Nose instrument and the e-Tongue was designed using six potentiometric sensors. Four different commercial brands along with eleven fruit juice varieties were characterised using the e-Nose and the e-Tongue as individual techniques, followed by a combination of the two together. Applying Principal Component Analysis (PCA) separately on the respective e-Nose and e-Tongue data, only few distinct groups were discriminated. However, by employing the low-level of abstraction data fusion technique, very impressive findings were achieved. The Fuzzy ARTMAP neural network reached a 100% success rate in the recognition of the eleven-fruit juices. Therefore, data fusion approach can successfully merge individual data from multiple origins to draw the right conclusions that are more fruitful when compared to the original single data. Hence, this work has demonstrated that data fusion strategy used to combine e-Nose and e-Tongue signals led to a system of complementary and comprehensive information of the fruit juices which outperformed the performance of each instrument when applied separately.
The aim of the study was to evaluate the reproducibility of the Dietary Habits and Nutrition Beliefs Questionnaire (KomPAN) in Polish adolescents and adults, including the assessment of indexes ...developed based on the questionnaire. In total, the study involved 954 subjects aged 15⁻65 (53.9% females). Interviews using the interviewer-administered questionnaire (IA-Q) in healthy subjects (
299) and the self-administered questionnaire (SA-Q) in healthy subjects (
517) and outpatients (
138) were conducted and repeated after two weeks. Considering the consumption frequency of 33 food items, the cross-classification (test-retest) agreement of classification into the same category obtained for IA-Q in healthy subjects ranged from 72.2% (fruit juices) to 91.6% (energy drinks); the kappa statistic was >0.60 for all food items. For SA-Q conducted in healthy subjects the cross-classification agreement ranged from 63.8% (vegetable oils, margarines, mixes of butter and margarines) to 84.7% (lard); the kappa statistic was >0.50 for all food items. For SA-Q in outpatients, the cross-classification agreement ranged from 42.0% (both fruit juices and white rice, white pasta, fine-ground groats) to 92.0% (energy drinks); the kappa statistic was ≥0.40 for 20/33 food items. The kappa statistic for lifestyle items ranged 0.42⁻0.96, and for the nutrition knowledge level it ranged 0.46⁻0.73. The questionnaire showed moderate to very good reproducibility and can be recommended to assess dietary habits, lifestyle and nutrition knowledge of healthy adolescents and adults and those suffering from chronic diseases, after validation and/or calibration study is carried out. The reproducibility of the interviewer-administered questionnaire was better than its self-administered version. The reproducibility of the self-administered questionnaire was better in healthy subjects than in outpatients.
Although numerous studies have reported the benefits of apple consumption on cardiometabolic health parameters and chronic disease prevention, few have focused on the effects of apple juice ...specifically. Juice consumption may be a convenient way to take advantage of the health effects of the bioactive components present in apples. The present review aims to summarize the current literature on health benefits of apple juice as reported in clinical trials in humans. Of the 67 studies retained, 20 interventional studies on humans were reviewed. Overall, cloudy apple juice consumption was found to be associated with several markers of cardiovascular health that may ultimately be relevant for cancer and neurodegenerative diseases. Most of the documentation was found regarding oxidative stress, as well as observations with other parameters such as markers of inflammation, lipid profile, and diabetes. This review suggests that, in 20 studies, apple juice consumed in moderation exerts positive effects on markers of cardiovascular disease risk (particularly on oxidative stress).
Fast and accurate detection of microorganisms is of key importance in clinical analysis and in food and water quality monitoring. Salmonella typhimurium is responsible for about a third of all cases ...of foodborne diseases and consequently, its fast detection is of great importance for ensuring the safety of foodstuffs.
We report the development of a label-free impedimetric aptamer-based biosensor for S. typhimurium detection. The aptamer biosensor was fabricated by grafting a diazonium-supporting layer onto screen-printed carbon electrodes (SPEs), via electrochemical or chemical approaches, followed by chemical immobilisation of aminated-aptamer. FTIR-ATR, contact angle and electrochemical measurements were used to monitor the fabrication process. Results showed that electrochemical immobilisation of the diazonium-grafting layer allowed the formation of a denser aptamer layer, which resulted in higher sensitivity. The developed aptamer-biosensor responded linearly, on a logarithm scale, over the concentration range 1×101 to 1×108CFUmL−1, with a limit of quantification (LOQ) of 1×101CFUmL−1 and a limit of detection (LOD) of 6CFUmL−1. Selectivity studies showed that the aptamer biosensor could discriminate S. typhimurium from 6 other model bacteria strains. Finally, recovery studies demonstrated its suitability for the detection of S. typhimurium in spiked (1×102, 1×104 and 1×106CFUmL−1) apple juice samples.
•Rapid (30min) label-free detection of S. typhimurium.•Highly selective and sensitive (1×101CFUmL−1) biosensor for S. typhimurium.•Label free detection of S. typhimurium in spiked apple juice samples.•Diazonium based architecture for robust and sensitive electrochemical aptasensor.
Ozone is activated oxygen and it is referred to as a triatomic form of oxygen. It is a natural agent and has a broad antimicrobial property, which together with an oxidation potential, make it an ...attractive option for the food industry. This article focuses on the use of ozone for preservation of vegetables, fruits and fruit juices, and highlights the inactivation mechanism of microorganisms. The application of ozone in grain storage and the quality of ozone treated grains is discussed, along with the reaction kinetics of ozone in grains.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Glucoraphanin from broccoli and its sprouts and seeds is a water soluble and relatively inert precursor of sulforaphane, the reactive isothiocyanate that potently inhibits neoplastic cellular ...processes and prevents a number of disease states. Sulforaphane is difficult to deliver in an enriched and stable form for purposes of direct human consumption. We have focused upon evaluating the bioavailability of sulforaphane, either by direct administration of glucoraphanin (a glucosinolate, or β-thioglucoside-N-hydroxysulfate), or by co-administering glucoraphanin and the enzyme myrosinase to catalyze its conversion to sulforaphane at economic, reproducible and sustainable yields. We show that following administration of glucoraphanin in a commercially prepared dietary supplement to a small number of human volunteers, the volunteers had equivalent output of sulforaphane metabolites in their urine to that which they produced when given an equimolar dose of glucoraphanin in a simple boiled and lyophilized extract of broccoli sprouts. Furthermore, when either broccoli sprouts or seeds are administered directly to subjects without prior extraction and consequent inactivation of endogenous myrosinase, regardless of the delivery matrix or dose, the sulforaphane in those preparations is 3- to 4-fold more bioavailable than sulforaphane from glucoraphanin delivered without active plant myrosinase. These data expand upon earlier reports of inter- and intra-individual variability, when glucoraphanin was delivered in either teas, juices, or gelatin capsules, and they confirm that a variety of delivery matrices may be equally suitable for glucoraphanin supplementation (e.g. fruit juices, water, or various types of capsules and tablets).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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