Showing posts with label Antioxidants. Show all posts
Showing posts with label Antioxidants. Show all posts

Saturday, 19 September 2020

Use of Spectroscopic Techniques to Monitor Changes in Food Quality during Application of Natural Preservatives: A Review

 Antioxidants 2020, 9(9), 882

DOI:10.3390/antiox9090882


Consumer demand for food of high quality has driven research for alternative methods of food preservation on the one hand, and the development of new and rapid quality assessment techniques on the other hand. Recently, there has been a growing need and interest in healthier food products, which has led to an increased interest in natural preservatives, such as essential oils, plant extracts, and edible films and coatings. Several studies have shown the potential of using biopreservation, natural antimicrobials, and antioxidant agents in place of other processing and preservation techniques (e.g., thermal and non-thermal treatments, freezing, or synthetic chemicals). Changes in food quality induced by the application of natural preservatives have been commonly evaluated using a range of traditional methods, including microbiology, sensory, and physicochemical measurements. Several spectroscopic techniques have been proposed as promising alternatives to the traditional time-consuming and destructive methods. This review will provide an overview of recent studies and highlight the potential of spectroscopic techniques to evaluate quality changes in food products following the application of natural preservatives.

Tuesday, 17 September 2019

The Potential of Seaweeds as a Source of Functional Ingredients of Prebiotic and Antioxidant Value

 Antioxidants 2019, 8(9), 406


Two thirds of the world is covered by oceans, whose upper layer is inhabited by algae. This means that there is a large extension to obtain these photoautotrophic organisms. Algae have undergone a boom in recent years, with consequent discoveries and advances in this field. Algae are not only of high ecological value but also of great economic importance. Possible applications of algae are very diverse and include anti-biofilm activity, production of biofuels, bioremediation, as fertilizer, as fish feed, as food or food ingredients, in pharmacology (since they show antioxidant or contraceptive activities), in cosmeceutical formulation, and in such other applications as filters or for obtaining minerals. In this context, algae as food can be of help to maintain or even improve human health, and there is a growing interest in new products called functional foods, which can promote such a healthy state. Therefore, in this search, one of the main areas of research is the extraction and characterization of new natural ingredients with biological activity (e.g., prebiotic and antioxidant) that can contribute to consumers’ well-being. The present review shows the results of a bibliographic survey on the chemical composition of macroalgae, together with a critical discussion about their potential as natural sources of new functional ingredients.


Friday, 22 March 2019

Dissipation of Three Fungicides and Their Effects on Anthocyanins and Color of Monastrell Red Wines

Int. J. Mol. Sci. 2019, 20(6), 1447


The effect of fungicides on fermentation is of paramount importance to control the quality and safety of wines. In this work, the quality (enological parameters, color, phenolic content, antioxidant activity, and fungicide residues) of wines from Monastrell grapes fortified with iprovalicarb, mepanipyrim, and tetraconazole fungicides was evaluated. Along the winemaking process, initial residues of mepanipyrim and tetraconazole were removed in more than 90% while the dissipation of iprovalicarb was around 73%. Significant statistical differences were found in the presence of iprovalicarb and mepanipyrim residues, especially at the highest concentration assayed. For both fungicides, increases in the volatile acidity (between 4 and 8.6 times), the lactic acid content (between 8.6 and 20.5 times), the percentage of polymeric anthocyanins (between 1.3 and 1.7 times), and also a slight increase of the total phenolic index and the total anthocyanin content determined by spectrophotometry were observed. On the contrary, the total monomeric anthocyanins content decreased about 16.3% and 28.6% in the presence of iprovalicarb and mepanipyrim, respectively. These results could be related to a higher development of acetic acid or lactic bacteria in the presence of these fungicides. The color of the final wines was also different in comparison with the control, with a higher yellow component, color intensity, tonality, and hue angle because of pH changes in the medium. Tetraconazole fermentations had a more similar trend to the control wine, probably due to the lower concentration of this fungicide in the grape must at the initial time. No effects on the antioxidant activity was observed for any of the target fungicides. A multivariate statistical analysis was done to view the interrelationships between different variables (color and anthocyanins profile). The obtained model allowed the wines to be separated according to the fungicide treatment applied.


Saturday, 5 May 2018

Encapsulation of Essential Oils by Cyclodextrins: Characterization and Evaluation

Cyclodextrin: A Versatile Ingredient


The essential oils normally had low physicochemical stability and low solubility in water. These facts limit their industrial applications in general and in food formulations particu- larly. This chapter characterizes the physicochemical properties and the antioxidant and antimicrobial activities of three encapsulated essential oils – guava leaf, yarrow and black pepper essential oils – in hydroxypropyl-β-cyclodextrin (HPβCD).



Thursday, 4 January 2018

Bioaccessibility and potential bioavailability of phenolic compounds from achenes as a new target for strawberry breeding programs

Food Chemistry 248 (2018) 155-165


Strawberry is a major natural source of bioactive compounds. Botanically, strawberry is an aggregate fruit consisting of a fleshy floral receptacle that bears a cluster of real dry fruits (achenes). Existing knowledge on the phenolic composition of achenes and its contribution to that of the whole fruit is limited. Also, the gastric and intestinal bioavailability of phenols is poorly known. In this work, a combination of spectrophotometric and HPLC–DAD methods was used to analyse the phenolic composition of whole fruits and achenes before and after in vitro digestion. Five different phenol families were identified. Also, achenes were found to contribute a sizeable fraction of phenolic acids and hydrolysable tannins in the whole fruit. Because the mere presence of phenolic compounds in a food matrix does not ensure their ready absorption and bioavailability, polyphenol potential bioavailability could be an effective selection criterion for strawberry breeding programs aimed at improving dietary healthiness.


Tuesday, 17 October 2017

Antioxidant and antimicrobial properties of encapsulated guava leaf oil in hydroxypropyl-beta-cyclodextrin

Industrial Crops and Products
https://doi.org/10.1016/j.indcrop.2017.10.027


The essential oil from guava leaves has low physicochemical stability and low solubility in water, what limits its application in food formulations. This study aimed to characterize the physicochemical properties and the antioxidant and antimicrobial activities of encapsulated guava leaf oil in hydroxypropyl-β-cyclodextrin (HPβCD). Inclusion complex formation of guava leaf oil and HPβCD was determined by several techniques. Antioxidant activity of encapsulated guava leaf oil was more stable to sunlight exposure than free guava leaf oil by 26–38%. The antibacterial activity of guava leaf oil against Staphylococcus aureus and Escherichia coli was improved by 4 and 2 times after encapsulation in HPβCD, respectively.

Thursday, 2 February 2017

A Critical Review of the Characterization of Polyphenol-Protein Interactions and of Their Potential Use for Improving Food Quality.

Curr Pharm Des. 2017;23(19):2742-2753. 


Background:
Interest in protein-phenol interactions in biological systems has grown substantially in recent decades.

Methods:
The interest has focused largely on food systems in response to reports on the prominent roles of phenolic compounds in nutrition and health.

Results:
Phenolic compounds can have both favourable and adverse nutritional effects. Polyphenols are widely known for their antioxidant, anti-inflammatory, anticancer and antiaging properties; however, they have also been ascribed anti-nutritional effects resulting from interactions with some proteins and enzymes. Interactions between proteins and polyphenols can additionally influence food quality by altering some physical-chemical and sensory properties of foods. These effects may be useful to develop new products in food science and technology provided the nature of physical-chemical interactions between proteins and phenols is accurately elucidated. In this paper, we review the different possible modes of interaction between selected food proteins and phenolic compounds.

Conclusion:
Existing knowledge on the mechanisms behind polyphenol-protein reactions, the structures of the resulting products and their potential uses is reviewed.

Sunday, 18 September 2016

Antioxidant ability of potato (Solanum tuberosum) peel extracts to inhibit soybean oil oxidation

Eur. J. Lipid Sci. Technol. (2016)
doi:10.1002/ejlt.201500419


Potato peels are an agro industrial waste of one of the major crops worldwide. However, the potential of potato peels as source of antioxidants in the food industry is not yet sufficiently known. In this work, the antioxidant effect of potato peel extract (PPE) on oxidative stability of soybean oil was evaluated. We found that the addition of low PPE concentrations to soybean oil at four different levels, expressed as chlorogenic acid concentrations (14.01, 20.37, and 31.94 ppm), affected lipid oxidation indices (peroxide, anisidine, and conjugated dienes values), fatty acid composition, and volatile compounds. Antioxidant effect increased with increasing dose extract. Inhibition percentages of hexanal production increased with the PPE concentration. In addition, low concentrations of PPE showed higher oxidation stability than control untreated samples. Overall, our study shows that low concentrations of PPE exhibited promising antioxidant activity to be applied over a wider range of products in the food industry.

Practical applications: The prevention of lipid oxidation during processing and storage of food products is of great concern in order to obtain products of high quality and health. Together with the fact that synthetic antioxidants may constitute a potential health hazard for consumers, interest in natural antioxidants and search on naturally occurring compounds with antioxidant activity has increased dramatically. The study of the antioxidant capacity of potato peel extracts to inhibit soybean oil oxidation provides information about an alternative antioxidant further are by-products of agro-industries and their use could represent a significant step toward maintaining an environmental balance.

Saturday, 1 March 2014

Development of an improved extraction and HPLC method for the measurement of ascorbic acid in cows' milk from processing plants and retail outlets


International Journal of Food Science & Technology
Volume 49, Issue 3, pages 679–688, March 2014



An improved extraction (2.5% HPO3, 5 mm dithiothreitol) and HPLC quantification methodology using a C–18 column at 35 °C and 0.1 m acetic acid (98%) and acetonitrile (2%) mobile phase was developed to quantify total ascorbic acid (AA) in commercial whole/semi-skim/skim raw/pasteurised/UHT milk packaged in opaque bags, transparent plastic, cardboard and Tetra Brik™. AA content ranged from 0.21 to 10 and from 3.4 to 16 mg L−1 in milk from retail outlets and processing plants, respectively, and was higher in organic milk. For same processor/lot samples, pasteurised milk showed higher AA content than UHT milk. This was not true for retail outlets samples. AA content was similar for whole/semi-skim and semi-skim/skim milk, but not for whole/skim comparisons. Among UHT samples, the AA content trend was whole<semi-skim<skim and lower for UHT milk in opaque plastic and Tetra Brik™ container. After 14 days at 4 °C in the dark, AA losses ranged 35–83% depending on milk type and preservation method with a higher AA retention in unopened containers.