Chemistry Journal of Moldova

Food chemistry

MORPHOLOGICAL AND THERMOANALYTICAL STUDY OF MODIFIED AVOCADO SEEDS STARCH WITH LACTIC ACID

Author(s):

Camila Delinski Bet, Lucas Henrique Waiga, Cristina Soltovski de Oliveira, Luiz Gustavo Lacerda, Egon Schnitzler


Field: Food chemistry
Type: Research paper
Issue: 2017 Volume 12, no.2
Pages: 13-18
Keywords: avocado starch, lactic acid, modification, thermal analysis.
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DOI: http://dx.doi.org/10.19261/cjm.2017.438   
 
Abstract (PDF)
Graphical Abstract: Avocado seeds starch was investigated after the modification with lactic acid using thermogravimetry and differential thermal analysis, differential scanning calorimetry, X-ray powder diffraction and scanning electron microscopy. After the modification, there was a decrease in the thermal stability of the starch, also the parameters measured by differential scanning calorimetry showed lower values. There was no difference in the morphology of the granules, which presented an oval and rounded shape. 



 

Downloads: 58

THE EFFECT OF STARTER CULTURE PRODUCING EXOPOLYSACCHARIDE ON PHYSICOCHEMICAL PROPERTIES OF YOGHURT

Author(s):

Anatoli Cartasev, Valeriu Rudic


Field: Food chemistry
Type: Research paper
Issue: 2017 Volume 12, no.2
Pages: 7-12
Keywords: yoghurt, starter culture, Streptococcus thermophilus, physicochemical properties.
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DOI:
http://dx.doi.org/10.19261/cjm.2017.440   
 
Abstract (PDF)
Graphical Abstract: The purpose of this research was to investigate the impact of indigenous starter culture capable to synthesize exopolysaccharides (EPSs) on physicochemical properties of yoghurt. Two starter cultures, EPS-producing and non-EPS-producing, were developed from the autochthonous lactic acid bacteria strains by pairwise combining Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus strains. In the present study the ropy strain of Streptococcus thermophilus CNMN LB-50 was incorporated in EPS-producing starter culture. The microstructure, viscosity, EPS amount, structural properties and syneresis of yoghurt samples were assessed. It has been established that the EPS-producing starter culture provided a reduction of structural degradation and increased degree of structural recovery after deformation. Besides, it was observed that the use of EPS synthesized starter culture in yoghurt production restrains the syneresis of the gel.

 
 

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THE SURFACE PHOTOCHEMISTRY OF PROCYMIDONE IN PRESENCE OF AMMONIUM FERRIC CITRATE

Author(s):

Ivan Osipov


Field: Food chemistry
Type: Short communication
Issue: 2015 Volume 10, no.2
Pages: 89-91
Keywords: procymidone, ammonium ferric citrate, silica, phototransformation.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2015.10(2).11

Graphical Abstract:
 Procymidone was chosen as the model compound and its phototransformation was followed under sunlight irradiation. The main photodegradation products on silica is 3,5-dichloroaniline and 3,5-diclorphenilisocyanate. The use of ammonium ferric citrate enhances the degradation of the procymidone.


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EQUILIBRIUM AND KINETIC PARAMETERS FOR THE SEDIMENTATION OF TARTARIC SALTS IN YOUNG WINES

Author(s):

Ecaterina Covaci, Gheorghe Duca, Rodica Sturza


Field: Food chemistry
Type: Research paper
Issue: 2015 Volume 10, no.1
Pages: 33-41
Keywords: kinetic parameters, young wines, crystalline stabilization, Arrhenius plots.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2015.10(1).04

Graphical Abstract:
 In young wines potassium hydrogen tartrate is always present in supersaturating concentration and crystallizes spontaneously. The aim of this study is to obtain kinetic parameters, which explain the stability of young wines during the stabilization treatments. The kinetic and equilibrium parameters were evaluated and discussed. According to the obtained experimental results, the optimal regime for production and stabilization of young wines has been established.

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THERMODYNAMIC PARAMETERS OF POTASSIUM BITARTRATE DURING THE YOUNG WINES COLD STABILIZATION

Author(s):

Ecaterina Covaci


Field: Food chemistry
Type: Research paper
Issue: 2015 Volume 10, no.1
Pages: 42-45
Keywords: stabilization, tartaric salts, thermodynamic parameters, young wines.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2015.10(1).05

Graphical Abstract:
 The present work was undertaken to study the effect of the treatment temperature on the potassium bitartrate stability and composition of young wines. The thermodynamic parameters, namely ∆G°, ∆H°, ∆S° were calculated to predict the nature of potassium hydrogen tartrate (KHT) precipitation. According to the achieved results, the exothermal nature and thermodynamical feasibility of KHT precipitation in young wines were established. Based on thermodynamics, negative ∆G°, ∆H° values and positive ∆S° value give a spontaneous KHT process at lower temperatures.

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THE INFLUENCE OF APPLIED STABILIZATION METHOD ON THE CRYSTALLINE STABILITY OF YOUNG WHITE WINES

Author(s):

Ecaterina Covaci, Gheorghe Duca, Rodica Sturza


Field: Food chemistry
Type: Research paper
Issue: 2013 Volume 8, no.2
Pages: 73-77
Keywords: young white wine, crystalline stabilization, suspension of bentonite, conductivity
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2013.08(2).08

Graphical Abstract:
Crystalline precipitate which occurs due to the presence of tartaric salts is frequently encountered in young wines in form of white-dirty lamellar crystals at the bottom of tank. The aim of the study is to prevent the tartaric salts from crystallization in young wine blend Biance/Sauvignon by implementing various schemes and procedures.

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WATER ACTIVITY CONCEPT AND ITS ROLE IN STRAWBERRIES FOOD

Author(s):

E. Sandulachi, P. Tatarov


Field: Food chemistry
Type: Research paper
Issue: 2012 Volume 7, no.2
Pages: 103-115
Keywords: water activity, frozen strawerries, sugar addition, processing, osmotic treatment, stability.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2012.07(2).07

Graphical Abstract:
 This paper presents the study information related to the processing of fruit by combined methods. Is presented on the concept of water activity and its role in product quality; mathematical modeling methods (GAB, BET et al.) in estimate the activity coefficients of non-electrolyte and electrolyte mixture. Have been carried experimental research to study the evolution of the biologically active substances in frozen strawberries with and without sugar addition. It proved that frozen strawberries with sugar, during storage are more stable regarding antioxidants content that strawberry frozen without sugar.

Downloads: 51

THE STUDY OF PHTHALATES MIGRATION IN WINE PRODUCTS BY GC-MS METHOD

Author(s):

Gh. Duca, R. Sturza, D. Lazakovich


Field: Food chemistry
Type: Research paper
Issue: 2012 Volume 7, no.2
Pages: 98-102
Keywords: phthalates, wine, gas-chromatography, mass-spectrometry, migration.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2012.07(2).08

Graphical Abstract:
 A number of studies have shown phthalates’ potential impact on human health due to their carcinogenic and endocrinedisrupting effects. More than 2000 analyses for determination of phthalates’ rests in alcoholic beverages were done in the laboratory of National Center for Quality Testing of the Alcoholic Beverages (Republic of Moldova) using modern method of analysis like GC-MS. This article is an extended abstract of a communication presented at the Conference Ecological Chemistry 2012.

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MODIFIED SCREEN-PRINTED CARBON ELECTRODES WITH TYROSINASE FOR DETERMINATION OF PHENOLIC COMPOUNDS IN SMOKED FOOD

Author(s):

V. Dragancea, R. Sturza, M. Boujtita


Field: Food chemistry
Type: Research paper
Issue: 2010 Volume 5, no.2
Pages: 47-53
Keywords: screen-printed carbon electrode SPCE; biosensor; phenol; tyrosinase; gas chromatography.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2010.05(2).06

Graphical Abstract:
A screen-printed carbon electrode modified with tyrosinase (SPCE-Tyr/Paa/Glut) has been developed for the determination of phenol concentration in real samples. The resulting SPCE-Tyr/Paa/Glut was prepared in a one-step procedure, and was then optimized as an amperometric biosensor operating at 0 mV versus Ag/AgCl for phenol determination in flow injection mode. Phenol detection was realized by electrochemical reduction of quinone produced by tyrosinase activity. The possibility of using the developed biosensor to determine phenol concentrations in various smoked products (bacon, ham, chicken and salmon) was also evaluated. Gas chromatography (GC) method was used for result validation obtained in flow injection mode using amperometric biosensor. The result showed good correlation with those obtained by flowinjection analysis (FIA).

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ANALYSIS OF THE PHTHALATE CONTENT LEVELS IN WINE PRODUCTS

Author(s):

Duca Gheorghe, Sturza Rodica, Gaina Boris, Lazacovici Dmitri


Field: Food chemistry
Type: Research paper
Issue: 2011 Volume 6, no.2
Pages: 65-69
Keywords: phthalates, wine, gas-chromatography, mass-spectrometry, dibutylphthalate.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2011.06(2).14

Graphical Abstract:
 In the context of studies conducted in the laboratory of National Center for Quality Testing of the Alcoholic Beverages (Republic of Moldova) were included more than 1300 samples of the bottled wine and base-wine for the presence of most widespread and toxic phthalate – dibutylphthalate using modern method of analysis like GC-MS. Results display presences DBP in 85 % of studied samples of wines, i.e. a content of DBP more than LOQ (0.01mg/dm3). Has been determined that contamination of phthalates has a technogenic character, and it is the result of contact with polymeric materials. Optimum conditions of extraction DBP from liquid samples were obtained.

Downloads: 36