Czech Journal of Food Sciences, 2012 (vol. 30), issue 2
Microwave-assisted phosphorylation of soybean protein isolates and their physicochemical properties
Xi-Bo Wang, Yu-Jie Chi
Czech J. Food Sci., 2012, 30(2):99-107 | DOI: 10.17221/91/2011-CJFS 
In order to improve the functional properties of soybean protein isolates (SPI), microwave-assisted phosphorylation (MAP) was applied. The result showed that after microwaving at 600 W for 3 min, the phosphorylation level of SPI reached 35.72 mg/g, emulsifying activity and stability were increased 2 times and 1.4 times, respectively, the solubility was increased by 26.0% and the apparent viscosity was decreased by 13.5%. The charge density, content of sulfhydryl groups, and surface hydrophobicity increased significantly. The infra-red spectroscopic analysis indicated PO43- primary and lysine residues for phosphoric acid esterification....
Inactivation of mesophilic bacteria in milk by means of high intensity ultrasound using response surface methodology
Zoran Herceg, Edita Juraga, Brankica Sobota-Šalamon, Anet Režek-Jambrak
Czech J. Food Sci., 2012, 30(2):108-117 | DOI: 10.17221/93/2011-CJFS
High-intensity ultrasound was used to investigate the inactivation of microorganisms in raw bovine milk. Raw bovine milk with 4% of milk fat was treated with ultrasonic probe that was 12 mm in diameter and with 20 kHz frequency immerged in milk directly. In the ultrasound treatment, three parameters were varied according to the statistical experimental design. The centre composite design was used to design and optimise the experimental parameters: temperature (20, 40, and 60°C), amplitude (120, 90, and 60 µm), and time (6, 9, and 12 min). All analyses were performed immediately after sonication and after 3 days and 5 days of storage under refrigeration...
Formulation, physicochemical, nutritional and sensorial evaluation of corn tortillas supplemented with chía seed (Salvia hispanica L.)
Rodolfo Rendón-Villalobos, Amanda Ortíz-Sánchez, Javier Solorza-Feria, Cesar Arnulfo Trujillo-Hernández
Czech J. Food Sci., 2012, 30(2):118-125 | DOI: 10.17221/393/2010-CJFS
Composite flours containing 5%, 10%, 15%, and 20% of chia seed flour and corn were used for tortilla formulations. The effects of chia powders supplementation on the physicochemical and sensorial characteristics as well as starch digestibility of the tortillas were evaluated. Nutritionally, all chia tortillas had significantly higher levels (P < 0.001) of protein, lipids, and total dietary fibre than the control. The reduced enzymatic starch hydrolysis rate and predicted glycemic index recorded for the chia seed-added tortilla indicated slow digestion features. Sensory evaluation did not show significant (P > 0.05)...
The process parameters for non-typical seeds during simulated cold deep oil expression
Robert Rusinek, Rafał Rybczyński, Jerzy Tys, Marzena Gawrysiak- Witulska, Małgorzata Nogala-Kałucka, Aleksander Siger
Czech J. Food Sci., 2012, 30(2):126-134 | DOI: 10.17221/503/2010-CJFS
We have determined the parameters of oil expression process for non-typical seeds of oil-producing plants, such as quince tree, safflower, fennel-flower, cuckoo-flower, tarweed, lallemantia, sea-buckthorn, borage, evening primrose, mustard, and others. The relative moisture of most of the seeds tested ranged from 5.5% to 8.9%. The values of the oil point pressure obtained for the seeds permitted detailed classification of the plant species under study into 7 seed hardness groups. The largest group belonged to the pressure range from 10 to 15 MPa (oil flax, spring rapeseed cvs Bronowski, Mazowiecki, and Star, spring rape cv. Porkland and local...
Preparation of non-alcoholic naturally carbonated beverage using yeast isolate from whey beverage
Saloni Jairath, Parampal Sahota, Gulab Pandove
Czech J. Food Sci., 2012, 30(2):135-143 | DOI: 10.17221/248/2010-CJFS
Four pure yeast isolates from feta cheese whey beverage were phenotypically characterised and D1/D2 domain of 26S rRNA and Internal Transcribed Spacer (ITS) region were sequenced. These isolates were identified as Clavispora lusitaniae (84), Candida sp. YS12A (86), Clavispora lusitaniae (B82), and Candida hyderabadensis (S82). The fermentation potentials of all yeast isolates were determined in plum, amla, lemon, guava, kinnow, and pineapple, and Clavispora lusitaniae (84) was reported as the best yeast for carrying out fermentation with CO2 levels of 1.5 bar. Using Clavispora...
Ethanol biosynthesis and hydrocyanic acid liberation during fruit mashes fermentation
Maria Balcerek, Józef Szopa
Czech J. Food Sci., 2012, 30(2):144-152 | DOI: 10.17221/251/2010-CJFS
The biosynthesis of ethanol and release of hydrocyanic acid are important factors characterising the fermentation process of fruit mashes. The effects were determined of the fruit pretreatment and method of fermentation (with or without the addition of wine yeast) on the dynamics of ethanol biosynthesis and hydrocyanic acid liberation during fruit mashes fermentation and its concentrations in the spirits obtained. Depending on the fermentation variants, the highest rate of ethanol biosynthesis was observed between the first and third days of plum mashes fermentation, and between the first and fourth days of chokeberry mashes fermentation. In the majority...
Antioxidant activity coefficient, mechanism, and kinetics of different derivatives of flavones and flavanones towards superoxide radical
Safeer AHMED, Faria SHAKEEL
Czech J. Food Sci., 2012, 30(2):153-163 | DOI: 10.17221/447/2010-CJFS
A systematic investigation of the electrochemically generated superoxide radical (O2●-) has been conducted in the presence of some flavonoids. Cyclic voltammetry was used to generate O2●- by reducing the molecular oxygen in DMSO at room temperature. The scavenging of the radical was monitored by the decrease in anodic or/and cathodic currents while linearly increasing the concentration of the flavonoid. The strength of interaction was quantified in terms of the binding constant (Kb)values ranging from 1 × 102 and 5 × 103M-1. The antioxidant...
Isolation of some compounds from nutmeg and their antioxidant activities
Jian-Ping Hou, Hou Wu, Yi Wang, Xin-Chu Weng
Czech J. Food Sci., 2012, 30(2):164-170 | DOI: 10.17221/509/2010-CJFS
Six compounds, licarin-B (1), dehydrodiisoeugenol (2), malabaricone B (3), malabaricone C (4), β-sitosterol (5), and daucosterol (6) were isolated from the seed (nutmeg) of Myristica fragrans Houtt and identified. Among them, malabaricone B was identified for the first time in nutmeg. Antioxidant activities of the isolated compounds were studied using oil stability index (OSI), reducing power, ABTS●+ scavenging, and DPPH● scavenging methods. The results showed that Malabaricone C is an efficient antioxidant agent which exhibits a stronger antioxidant activity than the commonly used synthetic antioxidants...
Effect of temperature on the antioxidant activity of phenolic acids
Zuzana Réblová
Czech J. Food Sci., 2012, 30(2):171-175 | DOI: 10.17221/57/2011-CJFS
The effect of temperature on the antioxidant activity of phenolic acids (gallic, gentisic, protocatechuic, syringic, vanillic, ferulic, caffeic, and sinapic; 0.5 mmol/kg) was studied in pork lard, using an Oxipres apparatus, at a temperature range of 90°C to 150°C. The antioxidant activity of all studied compounds decreased with increasing working temperature, whereas a linear relationship (P < 0.01) existed between temperature and the antioxidant activity in all cases. However, the relative rate of the antioxidant activity decrease with increasing temperature (i.e. in comparison with the activity at 90°C) was not the same for all studied...
Bacterial biofilms resist oxidising agents due to the presence of organic matter
Zoran Jaglic, Dana Červinková, Hana Vlková, Elleni Michu, Gabriela Kunová, Vladimír Babák
Czech J. Food Sci., 2012, 30(2):178-187 | DOI: 10.17221/214/2011-CJFS
This study evaluated the susceptibility of planktonic and biofilm cells of Staphylococcus spp. (n = 87), Klebsiella spp. (n = 30), and Escherichia coli (n = 74) isolates originating from food contact surfaces of milk and meat processing plants to benzalkonium chloride (BAC), sodium hypochlorite (NaClO), chloramine B (CAB), and peracetic acid (PAA). Bacterial growth and reduction of viable cells in the presence of disinfectants were determined in tryptone soya broth (TSB) and water, respectively. Biofilm positive isolates (n = 73) were tested for the presence of selected qac genes....
Chasing after minerality, relationship to yeasts nutritional stress and succinic acid production
Mojmír Baroň, Jaromír Fiala
Czech J. Food Sci., 2012, 30(2):188-193 | DOI: 10.17221/464/2010-CJFS
Minerality is certainly one of the most mysterious and most valuable tones of wine taste and it is very often associated with the concept of terroir. The isotachophoresis was used for determination of cations - minerals in two wines from vineyards with different soil conditions, with and without exceptional "minerality". However, it was found that it has nothing to do with minerals. More attention was paid to the relationship between the nutritional stress of yeasts and succinic acid production, which can result in a final difference in the taste of wine. In addition, sensory evaluation was used to reveal differences between wines with increasing...