Czech Journal of Food Sciences, 2021 (vol. 39), issue 3

Selected aspects of edible insect rearing and consumption - A reviewReview

Jiří Mlček, Anna Adámková, Martin Adámek, Marie Borkovcová, Martina Bednářová, Lenka Kouřimská, Veronika Hlobilová

Czech J. Food Sci., 2021, 39(3):149-159 | DOI: 10.17221/288/2020-CJFS  

The presented work brings a comprehensive study of edible insect farming with an impact on the environment and human health. The review focuses not only on commonly monitored parameters such as carbon footprint or feed conversion but also on waste management. It also highlights the positive and negative aspects of eating edible insect regarding human health. Compared to other livestock, the rearing of edible insect brings less environmental burden and higher environmental protection. This review aimed to summarise current knowledge and broaden the complex view of the issue.

Enzymatic degradation of polysaccharides in Chinese vinegar residue to produce alcohol and xyloseOriginal Paper

Kunyi Liu, Shulai Zhou, Qi Wang, Bin Jiang, Liran Yang, Bing Lu, Huawei Yuan

Czech J. Food Sci., 2021, 39(3):160-168 | DOI: 10.17221/326/2019-CJFS  

Vinegar residue is a key secondary waste in the brewing industry that is often disposed irresponsibly, due to its large quantity and lack of reasonably effective use, causing environmental pollution issues. NaOH was used to pretreat Chinese vinegar residue, and the reaction products were consumed by the enzyme complex and Saccharomyces cerevisiae 1300 during the stage of simultaneous saccharification and fermentation (SSF). The results show that the optimal pretreatment conditions for Chinese vinegar residue were solid-to-liquid ratio of 1 : 11‏, NaOH concentration of 2.2%, pretreatment temperature of 63 °C, pretreatment time of 80 min,...

Isoflavones of the red and Hungarian clover and possible impact on animal dietOriginal Paper

Mirjana Petrović, Dejan Sokolović, Snežana Babić, Tomáš Vymyslický, Jordan Marković, Vladimir Zornić, Zora Dajić-Stevanović

Czech J. Food Sci., 2021, 39(3):169-175 | DOI: 10.17221/27/2020-CJFS  

The content of daidzein, genistein, formononetin, and biochanin A isoflavones was studied in natural populations of red and Hungarian clover, to estimate their impact on fodder quality and to determine directions in possible breeding programs. The study included 6 red clover (Trifolium pratense) and 6 Hungarian clover (Trifolium pannonicum) populations, collected in the central Balkans. The differences between the species and among the populations were analysed. The average content of total isoflavones was 1.393 mg g-1 and 0.487 mg g-1 of air dry matter in Hungarian clover, respectively. While the most prevailed isoflavone in red clover was biochanin...

Appraisal of antioxidant potential and biological studies of bogan bail (Bougainvillea glabra) leaf extracts using different solventsOriginal Paper

Muhammad Riaz, Humaira Fatima, Muhammad Misbah ur Rehman, Rahman Qadir, Shabbir Hussain, Abdul Hafeez, Abu Bakar Siddique

Czech J. Food Sci., 2021, 39(3):176-180 | DOI: 10.17221/273/2020-CJFS  

Current research work was performed to evaluate the antioxidant, antidiabetic, thrombolytic, and cytotoxic potential of Bougainvillea glabra leaf extracts with different solvents. Extraction of leaves was carried out by maceration using solvents of various polarity such as n-hexane, chloroform, ethyl acetate, n-butanol, and methanol. The highest values of total phenolic and flavonoid contents were assessed in methanolic extract, such as 58.57% and 29.41%, respectively. Antioxidant potential was measured by DPPH free radical, showing 65.16% scavenging activity in methanolic extract. Similarly, the reducing power of methanolic...

Effect of cryogenic freezing on the rheological and calorimetric properties of pasteurized liquid egg yolkOriginal Paper

Karina Ilona Hidas, Csaba Németh, Lien Phuong Le Nguyen, Anna Visy, Adrienn Tóth, Annamária Barkó, László Friedrich, Attila Nagy, Ildikó Csilla Nyulas-Zeke

Czech J. Food Sci., 2021, 39(3):181-188 | DOI: 10.17221/37/2021-CJFS  

The egg yolk undergoes an irreversible gelation process when freezing to -6 °C or lower. In this experiment, liquid egg yolk (LEY) was frozen in liquid nitrogen and stored at -18 °C for 150 days. The measurement of pH and colour of LEY were performed. The examination of the rheological and calorimetric properties of samples was also carried out. The results indicated that the pH of LEY changed significantly during frozen storage, increasing from 6.37 ± 0.02 to 6.58 ± 0.03 over five months. The colour of the samples also showed a significant change compared to the fresh sample. The rheological properties of the LEY also changed significantly...

Optimisation of the clarification of kiwifruit juice with tannic acid-modified chitosanOriginal Paper

Yujia Diao, Xueqing Yu, Chaohong Zhang, Yingjun Jing

Czech J. Food Sci., 2021, 39(3):189-196 | DOI: 10.17221/13/2021-CJFS  

Chitosan (CS) is an effective clarifying agent for fruit juice. However, its low antioxidant ability is a limitation in preserving the antioxidant capacity of the juice during clarification. In this work, an antioxidant CS derivative, tannic acid-modified CS (TA-CS), was used as a clarifying agent to optimise the clarification of kiwifruit juice. By using response surface methodology and the transmittance of the juice as a response, the optimal clarification conditions were obtained as follows: TA-CS concentration of 600 μg mL^-1, juice pH of 3.5, and heating temperature of 70 °C. Under the optimal conditions, TA-CS showed an excellent...

Homogeneity of the selected food mixesOriginal Paper

Dominika Barbara Matuszek, Karol Bierczyński, Andżelika Jędrysiak, Angelika Kraszewska

Czech J. Food Sci., 2021, 39(3):197-207 | DOI: 10.17221/225/2020-CJFS  

The article presents the results of homogeneity assessments for selected food mixes based on computer image analysis. The study was conducted on müsli and condiment mixes standardly available on the consumer market. A total of 40 different ready-for-use products were analysed. Collected samples from three package of each product were placed in a special chamber and then photographed. Photographs were then subjected to computer image analysis to acquire information on the percentage content of individual components. Homogeneity assessment was based on the contents of a selected component called tracer and the coefficient of variation (CV)....

Honey: Determination of volatile compounds, antioxidant and antibacterial activitiesOriginal Paper

Semiramis Karlidag, Merve Keskin, Sinan Bayram, Nazli Mayda, Asli Ozkok

Czech J. Food Sci., 2021, 39(3):208-216 | DOI: 10.17221/63/2021-CJFS  

Honey is an important functional food for human health and nutrition that is collected by honey bees and stored in the honeycombs. In this study, total phenolic content, antioxidant activity and volatile compounds of 13 different honey samples collected from various districts of Malatya province were investigated. As a result of this study, it was determined that the total phenolic content varied between 8.50 mg GAE 100 g^-1 and 73.90 mg GAE 100 g^-1 and it was observed that the honey samples were rich in aldehydes, aliphatic acid and esters, alcohols, hydrocarbons, carboxylic acid esters, ketones, terpenes, fatty acids and esters....

Dynamic high pressure microfluidization (DHPM): Physicochemical properties, nutritional constituents and microorganisms of yam juiceOriginal Paper

Mengpei Liu, Rong Wang, Jia Li, Lihua Zhang, Jiajia Zhang, Wei Zong, Wenjuan Mo

Czech J. Food Sci., 2021, 39(3):217-225 | DOI: 10.17221/284/2020-CJFS  

Dynamic high pressure microfluidization (DHPM) is considered an emerging and promising technique for the continuous production of fluid foods. This study measured the effect of DHPM on yam juice. After DHPM processing, the content of total soluble solids (TSS), turbidity, flavonoid and non-enzymatic browning was significantly decreased, with the biggest drops being 35.5, 86.2, 20.7, and 66.7%, respectively. Moreover, the average particle size was decreased from 1 944 nm to 358 nm, which showed a strong positive correlation with turbidity. The reduction coefficients and electric conductivity of Escherichia coli, Saccharomyces cerevisiae...

Utilisation of triticale (X Triticosecale Wittmack) and residual oat flour in breadmakingOriginal Paper

Anna Fraś, Kinga Gołębiewska, Damian Gołębiewski, Magdalena Wiśniewska, Marlena Gzowska, Dariusz R. Mańkowski

Czech J. Food Sci., 2021, 39(3):226-233 | DOI: 10.17221/249/2020-CJFS  

During the last few years, non-bread cereals, as a rich source of bioactive components, play an increasingly important role in the production of new healthier food. A large number of diet-related diseases in society requires developing and regular consumption of high-quality food. In this study, triticale flour was supplemented with residual oat flour (ROF), which is a by-product in the production of oat fibre concentrate, to obtain triticale-oat bread with improved chemical composition and quality. The flours obtained from 3 winter triticale cultivars were enriched with 10%, 15%, and 20% of ROF. An increasing level of ROF resulted in higher protein...