Czech Journal of Food Sciences, 2019 (vol. 37), issue 2
Chemical composition, antimicrobial and insecticidal activities of the tunisian Citrus aurantium essential oilsFood Analysis, Food Quality and Nutrition
Enis Ben Bnina, Hafedh Hajlaoui, Ikbal Chaieb, Majda Daami-Remadi, Moncef Ben Said, Hichem Ben Jannet
Czech J. Food Sci., 2019, 37(2):81-92 | DOI: 10.17221/202/2017-CJFS 
The chemical composition of volatile fractions from leaves, flowers and peels of Citrus aurantium growing in Tunisia obtained by hydrodistillation were analysed using GC and GC-MS. Furthermore, the isolated essential oils were evaluated for their in vitro antimicrobial activity against eight bacteria, eight phytopathogenic and nine human pathogenic fungi. The essential oils from peels and its main compound limonene have been found to possess strong contact toxicity against four storage-grain insects. The highest mortality rate was observed when the essential oil was applied against Cryptolestes...
Impacts of sodium chloride reduction in tomato soup system using potassium chloride and amino acidsFood Analysis, Food Quality and Nutrition
Banu Akgün, Seda Genc, Qiaofen Cheng, Özlem Isik
Czech J. Food Sci., 2019, 37(2):93-98 | DOI: 10.17221/140/2018-CJFS
Five different salt mixtures were prepared for the aim of lowering the sodium content of tomato soup and effects of using these mixtures on sensory, rheological, microbiological and physico-chemical properties of the final products were evaluated. The results showed that the use of salt substitutes did not affect flow behaviour of soup samples. Sensory profiling revealed that any group could not manage to reach the same saltiness level with the regular salt tomato soup (reference); nevertheless, tomato soups with salt formulation D (60% NaCl, 28% KCl, 6% l-lysine hydrochloride and 6% l-glutamic acid) and E (60% NaCl,...
RSM/ANN based optimized recovery of phenolics from mulberry leaves by enzyme-assisted extractionFood Analysis, Food Quality and Nutrition
Rahman Qadir, Farooq Anwar, Mazhar Amjad Gilani, Sadaf Zahoor, Muhammad Misbah ur Rehman, Muhammad Mustaqeem
Czech J. Food Sci., 2019, 37(2):99-105 | DOI: 10.17221/147/2018-CJFS
Recovery of phenolics from Morus alba leaves (MAL) and extraction into the solvent was optimized using enzyme-assisted extraction. The influence of four parameters, including enzyme concentration (EC), temperature (T), incubation time (t) and pH were investigated using rotatable central composite design (RCCD). Two factors, namely enzyme concentration and pH, exhibited significant effect on extraction efficacy yield of extractable phenolics from MAL. Furthermore, artificial neural network (ANN) model was executed to predict the relationship between dependent and independent variables. Among enzyme complexes (kemzyme...
Effect of muscle anatomical location on fatty acid composition of beaver (Castor fiber) femalesFood Analysis, Food Quality and Nutrition
Violeta Razmaite, Vidmantas Pileckas, Violeta Juškiene
Czech J. Food Sci., 2019, 37(2):106-111 | DOI: 10.17221/176/2018-CJFS
Ten beaver (Castor fiber) females were used in the experiment. The samples were excised from a different anatomical location of each beaver carcass used in the study: m. longissimus dorsi (LD), m. triceps brachii (shoulder), m. biceps femoris (thigh). Thigh muscles were characterized by the highest percentage of free fat followed by longissimus muscle and shoulder. The total proportions of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA), including many individual fatty acids, were affected by the muscle anatomical location. The fattiest thigh had the most favourable and highest...
Rapid determination of theaflavins by HPLC with a new monolithic columnFood Analysis, Food Quality and Nutrition
Jianyong Zhang, Hongchun Cui, Heyuan Jiang, Lei Fang, Weiwei Wang, Wei Su, Chunhua Xiong
Czech J. Food Sci., 2019, 37(2):112-119 | DOI: 10.17221/213/2018-CJFS
The quantitative determination of four theaflavin monomers by a rapid reversed-phase high performance liquid chromatographic method was developed. A new RP-18 end-capped column with particle size 2 µm and equilibrated to 35°C in a Shimadzu temperature controller module was used. Four theaflavin monomers were successfully separated in 8 min by the new strategy, comparing to 20-85 min by HPLC in the peer literature reports. Linear gradient elution: from 92% mobile phase A (v) to 76% mobile phase A (v) during early 3 min and then 92% mobile phase A (v) till 8 min at elution flow rate 1.5 ml/min. The limits of detection and quantification were in...
Effect of flour and sugar particle size on the properties of cookie dough and cookieFood Technology and Economy, Engineering and Physical Properties
Hüseyin Boz
Czech J. Food Sci., 2019, 37(2):120-127 | DOI: 10.17221/161/2017-CJFS
The effect of particle size of flour and sugar on the physical, sensorial and textural properties of cookie dough and cookie was investigated. According to the obtained data, both the sugar particle size and the flour particle size in cookie dough affected the hardness, adhesiveness, cohesiveness and springiness of the cookie doughs and this effect was statistically at a significant level (P < 0.01). The energy and force required for the dough extrusion dropped due to the reduction in the particle size of flour, while the reduction in the particle of sugar had the opposite effect. As the sugar and flour particle sizes decreased, the colour...
Modelling and characteristics of thin layer convective air-drying of thyme (Thymus vulgaris) leavesFood Technology and Economy, Engineering and Physical Properties
Osman YağIz Turan, Fatma Ebru Firatligil
Czech J. Food Sci., 2019, 37(2):128-134 | DOI: 10.17221/243/2017-CJFS
Fruit and vegetable dehydration has been extensively studied for the improvement of food preservation. Effects of drying temperature on the drying kinetics of thyme were investigated and a suitable drying model was obtained to describe the drying process. Drying behaviour of thyme leaves at temperatures of 50, 60, 70 and 80°C was determined by using a conventional drying oven, and moisture ratio and drying rates were calculated. Four different thin layer drying models, namely Lewis, Henderson and Pabis, Page, and logarithmic models, were used to fit the experimental moisture ratio data. Three statistical parameters: coefficient of determination (R2),...
Computer vision and artificial neural network techniques for classification of damage in potatoes during the storage processFood Technology and Economy, Engineering and Physical Properties
Krzysztof Przybył, Piotr Boniecki, Krzysztof Koszela, Łukasz Gierz, Mateusz Łukomski
Czech J. Food Sci., 2019, 37(2):135-140 | DOI: 10.17221/427/2017-CJFS
The research methodology consists of several stages to develop a noninvasive method of identifying the turgor of potato tubers during the storage. During the first stage, a graphic database (set of training data) has been created for selected varieties of potatoes. As a next step, special proprietary software called 'PID system' was used together with a commercial MATLAB package to extract parameters defining the digital image descriptors. This included: hue space models, shape coefficient and image texture. Thirdly, Artificial Neural Network (ANN) training was conducted with the use of Statistica and MATLAB tools. As a result of the analysis, a neural...