Foods

2552 KiB

Open AccessArticle

Validation of a Novel Technique and Evaluation of the Surface Free Energy of Food

by Tugce Senturk Parreidt, Markus Schmid and Carolin Hauser

Foods 2017, 6(4), 31; https://doi.org/10.3390/foods6040031 - 20 Apr 2017

Cited by 24 | Viewed by 7241

Characterizing the physical properties of a surface is largely dependent on determining the contact angle exhibited by a liquid. Contact angles on the surfaces of rough and irregularly-shaped food samples are difficult to measure using a contact angle meter (goniometer). As a consequence, [...] Read more.

Characterizing the physical properties of a surface is largely dependent on determining the contact angle exhibited by a liquid. Contact angles on the surfaces of rough and irregularly-shaped food samples are difficult to measure using a contact angle meter (goniometer). As a consequence, values for the surface energy and its components can be mismeasured. The aim of this work was to use a novel contact angle measurement method, namely the snake-based ImageJ program, to accurately measure the contact angles of rough and irregular shapes, such as food samples, and so enable more accurate calculation of the surface energy of food materials. In order to validate the novel technique, the contact angles of three different test liquids on four different smooth polymer films were measured using both the ImageJ software with the DropSnake plugin and the widely used contact angle meter. The distributions of the values obtained by the two methods were different. Therefore, the contact angles, surface energies, and polar and dispersive components of plastic films obtained using the ImageJ program and the Drop Shape Analyzer (DSA) were interpreted with the help of simple linear regression analysis. As case studies, the superficial characteristics of strawberry and endive salad epicarp were measured with the ImageJ program and the results were interpreted with the Drop Shape Analyzer equivalent according to our regression models. The data indicated that the ImageJ program can be successfully used for contact angle determination of rough and strongly hydrophobic surfaces, such as strawberry epicarp. However, for the special geometry of droplets on slightly hydrophobic surfaces, such as salad leaves, the program code interpolation part can be altered. Full article

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573 KiB

Open AccessArticle

Calabrian Goji vs. Chinese Goji: A Comparative Study on Biological Properties

by Mariarosa Ruffo, Ortensia Ilaria Parisi, Fabio Amone, Rocco Malivindi, Domenico Gorgoglione, Filomena De Biasio, Luca Scrivano, Vincenzo Pezzi and Francesco Puoci

Foods 2017, 6(4), 30; https://doi.org/10.3390/foods6040030 - 10 Apr 2017

Cited by 18 | Viewed by 7348

Abstract

Lycium barbarum (Goji) fruits are mainly cultivated in northwestern China and are well known for their beneficial and healthy effects. In this work, the biological and functional properties of Calabrian Goji extract, obtained from Goji berries cultivated in the Sibari Plain (in the [...] Read more.

Lycium barbarum (Goji) fruits are mainly cultivated in northwestern China and are well known for their beneficial and healthy effects. In this work, the biological and functional properties of Calabrian Goji extract, obtained from Goji berries cultivated in the Sibari Plain (in the Italian region of Calabria), were demonstrated. In order to evaluate the use of this extract as a food supplement for cognitive and mental disorders, the quantification of Carotenoids as Zeaxanthin equivalents was made. The antioxidant activity was investigated by evaluating the scavenging properties against 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals and by performing the ORAC (Oxygen Radical Absorbance Capacity) assay. The inhibition of lipid peroxidation was quantified by bleaching test and the ability to inhibit acetylcholinesterase enzyme and to scavenge nitric oxide radical was also evaluated. All the results were compared to those obtained from a Chinese Goji extract used as a reference. Based on the reported data, Calabrian Goji might be used as a food supplement with a possible application in cognitive disorders, mental impairments and other neurodegenerative diseases, due to its biological properties and the high levels of Carotenoids. Full article

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1889 KiB

Open AccessReview

Starch Characteristics Linked to Gluten-Free Products

by Stefan W. Horstmann, Kieran M. Lynch and Elke K. Arendt

Foods 2017, 6(4), 29; https://doi.org/10.3390/foods6040029 - 6 Apr 2017

Cited by 139 | Viewed by 42447

Abstract

The increasing prevalence of coeliac disease (CD) and gluten-related disorders has led to increasing consumer demand for gluten-free products with quality characteristics similar to wheat bread. The replacement of gluten in cereal-based products remains a challenge for scientists, due to its unique role [...] Read more.

The increasing prevalence of coeliac disease (CD) and gluten-related disorders has led to increasing consumer demand for gluten-free products with quality characteristics similar to wheat bread. The replacement of gluten in cereal-based products remains a challenge for scientists, due to its unique role in network formation, which entraps air bubbles. When gluten is removed from a flour, starch is the main component left. Starch is used as gelling, thickening, adhesion, moisture-retention, stabilizing, film forming, texturizing and anti-staling ingredient. The extent of these properties varies depending on the starch source. The starches can additionally be modified increasing or decreasing certain properties of the starch, depending on the application. Starch plays an important role in the formulation of bakery products and has an even more important role in gluten-free products. In gluten-free products, starch is incorporated into the food formulation to improve baking characteristics such as the specific volume, colour and crumb structure and texture. This review covers a number of topics relating to starch; including; an overview of common and lesser researched starches; chemical composition; morphology; digestibility; functionality and methods of modification. The emphasis of this review is on starch and its properties with respect to the quality of gluten-free products. Full article

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341 KiB

Open AccessFeature PaperArticle

Aromatic Plants: Antioxidant Capacity and Polyphenol Characterisation

by Charalampos Proestos and Theo Varzakas

Foods 2017, 6(4), 28; https://doi.org/10.3390/foods6040028 - 4 Apr 2017

Cited by 26 | Viewed by 7025

Abstract

The antioxidant properties and polyphenol content of some selected aromatic plants grown in Greece were studied. Plants were refluxed with 60% methanol after acid hydrolysis. The phenolic substances were quantified by High Performance Liquid Chromatography–Diode Array Detector (HPLC-DAD). The antioxidant capacity of the [...] Read more.

The antioxidant properties and polyphenol content of some selected aromatic plants grown in Greece were studied. Plants were refluxed with 60% methanol after acid hydrolysis. The phenolic substances were quantified by High Performance Liquid Chromatography–Diode Array Detector (HPLC-DAD). The antioxidant capacity of the extracts was determined with the Rancimat test using sunflower oil as substrate. Free radical scavenging activity was measured using the stable free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Results were compared with standard butylated hydroxytoluene (BHT) and ascorbic acid. Total phenol concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard. All plant extracts examined showed antioxidant capacity and contained phenolic compounds. Caffeic acid was detected in all the examined plant extracts. Ferulic acid was also detected in all the methanolic extracts, except from P. lanata, in rather high concentration. The amount of total phenolics varied slightly in plant materials and ranged from 8.2 mg to 31.6 mg of gallic acid/g dry sample. The highest amount was found in O. dictamnus, and the lowest in N. melissifolia. Full article

(This article belongs to the Special Issue Anti-Oxidants in Food: The Significance of Characterisation, Identification, Chemical and Biological Assays in Determining the Role of Anti-Oxidants in Food)

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201 KiB

Open AccessArticle

Mineral and Anti-Nutritional Contents of Niger Seed (Guizotia abyssinica (L.f.) Cass., Linseed (Linumusitatissimum L.) and Sesame (Sesamumindicum L.) Varieties Grown in Ethiopia

by Tesfaye Deme, Gulelat D. Haki, Nigussie Retta, Ashagrie Woldegiorgis and Mulatu Geleta

Foods 2017, 6(4), 27; https://doi.org/10.3390/foods6040027 - 1 Apr 2017

Cited by 32 | Viewed by 7656

Abstract

Oilseeds are rich sources of micronutrients and contribute to combating malnutrition caused by micronutrient deficiency. The objective of this study was to investigate the mineral and anti-nutritional contents of different varieties of niger seed, linseed and sesame. Five niger seed, eight linseed and [...] Read more.

Oilseeds are rich sources of micronutrients and contribute to combating malnutrition caused by micronutrient deficiency. The objective of this study was to investigate the mineral and anti-nutritional contents of different varieties of niger seed, linseed and sesame. Five niger seed, eight linseed and ten sesame varieties were used. Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) was used for mineral analysis and the standard method was adopted to estimate tannin and phytate. Twelve mineral elements; Ca, K, Mg, Na, P, B, Cu, Fe, Mn, S, Se and Zn were analyzed for each oilseed variety. In niger seed, phosphorous was the most abundant mineral element ranging from 661 to 867 mg/100 g and selenium was the least, ranging from 0.1 to 0.33 mg/100 g. Potassium was recorded in the range of 502 to 732 mg/100 g for linseed varieties. Calcium was the most common mineral element in sesame (1112 to 1787 mg/100 g). The average phytate contents of niger seed, linseed and sesame varieties were353 mg/100 g, 104 mg/100 g and 285 mg/100 g, respectively. Tannin ranged from 91 to 201 mg/100 g, 96 to 695 mg/100 g and 85 to 660 mg/100 g in niger seed, linseed and sesame, respectively. In conclusion, there is a significant variation among the varieties within each crop species as well as among the different oilseeds in terms of their mineral and anti-nutritional contents. Full article

847 KiB

Open AccessArticle

Characterization of Retail Conventional, Organic, and Grass Full-Fat Butters by Their Fat Contents, Free Fatty Acid Contents, and Triglyceride and Fatty Acid Profiling

by Annemieke M. Pustjens, Rita Boerrigter-Eenling, Alex H. Koot, Maikel Rozijn and Saskia M. Van Ruth

Foods 2017, 6(4), 26; https://doi.org/10.3390/foods6040026 - 31 Mar 2017

Cited by 21 | Viewed by 8361

Abstract

In the Netherlands, butter is produced from milk originating from three different production systems: conventional, organic, and grass-fed cows. The aim of the current study was to characterize these types of butters, and pinpoint distinct compositional differences. Retail conventional (n = 28), [...] Read more.

In the Netherlands, butter is produced from milk originating from three different production systems: conventional, organic, and grass-fed cows. The aim of the current study was to characterize these types of butters, and pinpoint distinct compositional differences. Retail conventional (n = 28), organic (n = 14), and grass (n = 12) full-fat butters were collected during the winter and summer seasons. Samples were analyzed for their fat content, free fatty acid (FFA) content, and triglyceride (TG) and fatty acid (FA) profiles. The fat content was significantly lower in conventional butters than in organic butters and the FFA content was significantly lower in conventional butters compared with grass butters. Also, organic butters differed significantly from their conventional counterparts with regard to their TG and FA profiles. The TG profiles of the organic and grass butters did not differ significantly. The FA profiles of grass butters were less distinct, since only a few FAs differed significantly from conventional (six FAs) and organic (eight FAs) butters. Full article

(This article belongs to the Special Issue Food Identity, Authenticity and Fraud: The Full Spectrum)

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1975 KiB

Open AccessArticle

Pigments in Extra-Virgin Olive Oils Produced in Tuscany (Italy) in Different Years

by Cristina Lazzerini and Valentina Domenici

Foods 2017, 6(4), 25; https://doi.org/10.3390/foods6040025 - 29 Mar 2017

Cited by 41 | Viewed by 8418

Abstract

Pigments are responsible for the color of olive oils, and are an important ingredient that is directly related to the quality of this food. However, the concentration of pigments can vary significantly depending on the climate conditions, harvesting time, and olive cultivars. In [...] Read more.

Pigments are responsible for the color of olive oils, and are an important ingredient that is directly related to the quality of this food. However, the concentration of pigments can vary significantly depending on the climate conditions, harvesting time, and olive cultivars. In this work, we quantified the main pigments in several extra-virgin olive oils produced from a blend of three cultivars (Moraiolo, Frantoio, and Leccino) typical of Tuscany (Italy) harvested in three different years: 2012, 2013, and 2014. Pigments—namely, β-carotene, lutein, pheophytin A, and pheophytin B—were quantified by a method based on the mathematical analysis of the near ultraviolet-visible absorption spectra of the oils. Data were analyzed by a multivariate statistical approach. The results show that the pigments’ content of extra-virgin olive oils produced in 2014 can be well distinguished with respect to previous years. This can be explained by the anomalous climate conditions, which strongly affected Italy and, in particular, Tuscany, where the olives were harvested. This study represents an interesting example of how pigment content can be significant in characterizing olive oils. Moreover, this is the first report of pigment quantification in extra-virgin olive oils produced in Tuscany. Full article

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1966 KiB

Open AccessArticle

A Comparative Study of Phenols in Apulian Italian Wines

by Andrea Ragusa, Carla Centonze, Maria E. Grasso, Maria F. Latronico, Pier F. Mastrangelo, Federica Sparascio, Francesco P. Fanizzi and Michele Maffia

Foods 2017, 6(4), 24; https://doi.org/10.3390/foods6040024 - 24 Mar 2017

Cited by 35 | Viewed by 7162

Abstract

Nutraceutics is a growing research field in which researchers study and attempt to improve the biological properties of metabolites in food. Wine is one of the most consumed products in the world and contains a plethora of molecules biologically relevant to human health. [...] Read more.

Nutraceutics is a growing research field in which researchers study and attempt to improve the biological properties of metabolites in food. Wine is one of the most consumed products in the world and contains a plethora of molecules biologically relevant to human health. In this article, several polyphenols with potential antioxidant activity were measured in wines from Apulia, in Southeast Italy. Hydroxytyrosol, gallic and syringic acids, luteolin, quercetin, and trans-resveratrol were identified and quantified by HPLC. The amount of the analyzed metabolites in wines were largely dependent on their color, with red ones being the richest compared to white and rose wines. Gallic acid was the most abundant polyphenol, followed by syringic acid and luteolin. Nevertheless, significant amounts of hydroxytyrosol, quercetin, and trans-resveratrol were also found. The average concentration of polyphenols found in these wines could have potential health-promoting effects, especially if consumed in moderate quantities on a regular basis. Full article

(This article belongs to the Special Issue Nutraceuticals: The New Frontier)

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Foods, Volume 6, Issue 4 (April 2017) – 8 articles

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