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Physicochemical and Structural Properties of Starch Isolated from Fresh and Dried Chestnuts and Chestnut Flour

María Dolores Torres1, Ramón Moreira1*, Francisco Chenlo1,
Marie Helene Morel2 and Cécile Barron2

1
Department of Chemical Engineering, University of Santiago de Compostela,
Rúa Lope Gómez de Marzoa s/n, ES-15782 Santiago de Compostela, Spain

2Laboratory of Cereal Technology and Agropolymers, ENSAM–INRA, 2 place Viala, FR-34060 Montpellier Cedex 1, France

Article history:

Received July 8, 2013

Accepted December 12, 2013

Key words:
gluten-free diet, optical microscopy, particle size, amylose, damaged starch

Summary:

Particle size distribution, colour, morphology and chemical composition of chestnut
(Castanea sativa Mill.) starches isolated from fresh chestnut fruits (S1), semi-dried chestnut fruits at room temperature (S2) and commercial chestnut flour (S3) were determined using several experimental techniques. All starches had a bimodal particle size distribution, particularly S1 showed two types of starch granules – small (1.5 μm diameter) and large granules (10.5 μm). Starch granule sizes depended on the moisture content of the samples, decreasing slightly in the following order S1>S2>S3; however, no significant differences were observed in the morphological analysis. Most of the granules exhibited round or oval shapes, and exceptionally, some of them featured trefoil shape, which is not usually found in other starches. Colour results indicated that S3 samples had the darkest colour, followed by S2 and S1. Tested chestnut starches showed significant differences in total starch content, with starch isolation being more selective in dried samples. All samples showed low damaged starch (<2.91 %) and intermediate amylose (from 17.0 to 25.8 %) content on dry mass basis. The lowest amount of amylose was obtained in S1, even though it was within the range of common commercial starches.

 

 

*Corresponding author:        ramon.moreira@usc.es
                                                   
     +34 881 816 759

                                           +34 981 528 050

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The Influence of the Addition of Polyacrylic Hydrogel on the Content of Proteins, Minerals and Trace Elements in Milk Protein Solutions


Aleksandar Ž. Kostić1, Mirjana B. Pešić1*, Miroljub B. Barać1,
Sladjana P. Stanojević1, Časlav M. Lačnjevac1, Ognjen D. Maćej1 and Mirjana D. Stojanović2

1Institute of Food Technology and Biochemistry, Department of Chemistry and Biochemistry,
Faculty of Agriculture, University of Belgrade, Nemanjina 6, RS-11081 Belgrade, Serbia

2Institute for Technology of Nuclear and Other Mineral Raw Materials, ITNMS, Boulevard of Franchet d’Espèrey 86, RS-11000 Belgrade, Serbia

Article history:
Received April 16, 2013

Accepted October 25, 2013

Key words:

milk protein solutions, polyacrylic hydrogel, mineral content, trace element
content

Summary:

Solutions of milk protein concentrate, whey protein concentrate and bovine serum albumin
(BSA) were treated with polyacrylic hydrogel to establish whether the hydrogel could be used for decontamination of heavy metal ions from milk protein-based products. The obtained results indicated that swelling of hydrogel in these solutions had different effects on their mineral, trace element and total protein content. Total protein and phosphorus content increased in milk protein concentrate and whey protein concentrate solutions after swelling of hydrogel without changes in their protein compositions. On the other hand, the protein content in BSA solution decreased after swelling. The content of Na did not change in milk protein concentrate solution, whereas it significantly increased in whey protein concentrate solution after hydrogel swelling. The content of Ca and Mg was reduced after the swelling in milk protein concentrate and whey protein concentrate solutions for 20.3–63.4 %, depending on the analysed sample and the mineral. The content of Zn did not change during swelling, whereas the content of Fe, Cu, Mn, Ni and Pb significantly decreased after hydrogel swelling in all analysed samples. According to the obtained results, the addition of polyacrylic hydrogel to milk and whey protein concentrate solutions can significantly decrease the content of heavy metal ions without affecting their protein composition. Therefore, this work could be useful in developing a new technological process for heavy metal purification of milk protein-based products.

 

 

*Corresponding author:        mpesic@agrif.bg.ac.rs
                                                   
     +381 11 219 9711

                                           +381 11 219 9711

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In vitro Antioxidant and Antibacterial Activity of Lamiaceae Phenolic Extracts: A Correlation Study

Ivana Generalić Mekinić1*, Danijela Skroza1, Ivica Ljubenkov2, Vida Šimat3,
Sonja Smole Možina4 and Višnja Katalinić1

1
University of Split, Faculty of Chemistry and Technology, Teslina 10, HR-21000 Split, Croatia

2University of Split, Faculty of Science, Teslina 12, HR-21000 Split, Croatia
3University of Split, University Department of Marine Studies, Livanjska 5/III, HR-21000 Split, Croatia
4University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia

Article history:

Received August 29, 2013

Accepted January 14, 2014

Key words:
Lamiaceae, phenolics, rosmarinic acid, antioxidant properties, antimicrobial activity,
principal component analysis

Summary:

Total phenols and phenolic subgroups of five Lamiaceae plant extracts (sage, thyme,
lemon balm, peppermint and oregano) were determined spectrophotometrically, whereas the individual phenolics were determined by high-performance liquid chromatography. The antioxidant activity of the extracts was evaluated by means of a multiple method approach, while the antibacterial activity was tested against major foodborne pathogens such as Campylobacter coli, Escherichia coli, Salmonella Infantis, Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus. The highest content of total phenolics and non-flavonoids was detected in the sage extract, which also showed the best antibacterial activity, especially against Gram-positive bacteria and C. coli. The best reducing power and free radical scavenging activity were obtained in lemon balm extract, with the highest content of rosmarinic acid. Additionally, the effect of the phenolics, especially rosmarinic acid, on biological properties of Lamiaceae plant extracts was investigated using principal component analysis. Rosmarinic acid showed good correlation with all antioxidant parameters, confirming its significant contribution to antioxidant activity of investigated plant extracts.

 

*Corresponding author:        gene@ktf-split.hr
                                                    
    +385 21 558 217

 


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Antibacterial Mode of Action of the Essential Oil Obtained from Chamaecyparis obtusa Sawdust on the Membrane Integrity of Selected Foodborne Pathogens


Vivek K. Bajpai§, Ajay Sharma§ and Kwang-Hyun Baek*

School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712–749, Korea

Article history:
Received April 11, 2013

Accepted December 9, 2013

Key words:

Chamaecyparis obtusa, sawdust, essential oil, antibacterial activity, foodborne
pathogens

Summary:

The present study examines the possible antibacterial mechanism of action of the essential
oil obtained from Chamaecyparis obtusa (COEO) sawdust against foodborne pathogenic bacteria. The COEO was obtained by microwave-assisted hydrodistillation of C. obtusa sawdust. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of COEO against the tested foodborne pathogens including Bacillus cereus ATCC 13061, Listeria monocytogenes ATCC 7644, Staphylococcus aureus ATCC 12600, Salmonella Typhimurium ATCC 43174 and Escherichia coli ATCC 43889 were found in the range from 62.5 to 500 μg/mL and from 125 to 1000 μg/mL, respectively. At the MIC concentrations, the COEO had potential inhibitory effect on the cell viability of the tested bacteria. In addition, the scanning electron microscopic analysis confirmed the inhibitory effect of COEO by revealing significant morphological alterations or rupture of the cell membranes of B. cereus ATCC 13061 and E. coli ATCC 43889. Moreover, the mode of action of COEO on the cell membrane of both Gram-positive B.cereus ATCC 13061 and Gram-negative E.coli ATCC 43889 bacteria was confirmed by marked release of extracellular adenosine 5’-triphosphate (ATP) and cellular material that absorbs at 260 nm, and by efflux of potassium ions. These findings suggest that COEO holds a broad-spectrum antibacterial efficacy, confirming its influence on the membrane integrity and morphological characteristics of tested foodborne pathogens.

 

 

*Corresponding author:     khbaek@ynu.ac.kr
                                       
  +82 53 810 4769




§Both authors contributed equally to this research


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