Czech Journal of Food Sciences - In Press
Impact of baking and proofing parameters on B complex vitamins retention of Arabic flatbread produced from wheat flour with different extraction ratesOriginal Paper
Mohammad Shahein, Yanal Albawarshi, Ayed Amr, Ashraf M. Al-khamaiseh
Considering the global wheat flour fortification regimes on Western types of bread, extensive research studies worldwide have discussed and analyzed the effect of processing conditions on nutritional, chemical, and biotechnological aspects of Western types of bread, however, the literature on Arabic bread processing is very limited. This study aims to determine the effect of baking temperature and time on the retention of B vitamins in a pocket-forming Arabic flatbread model system. Lean-formula, high-crumb flat Arabic bread (Thick Kmaj) was prepared by the straight dough method from three types of flour (patent, straight grade, and whole wheat) fortified with B vitamins. Doughs were fermented and proofed for 0, 30,60, and 90 minutes and baked at five temperatures (250, 300, 350, 400, and 450oC) for three different baking times (1, 2, and 3 minutes). Baking at lower temperatures i.e. < 300oC resulted in higher retention time values (more than 90%). Vitamin B6 showed exceptional retention values (about 100%) though decreased by increasing the baking temperature. Vitamin retention levels in the produced Arabic bread samples are similar to those found in the pan and other high-crumb bread types when baked at lower temperatures. The current study aimed at investigating and manipulating the processing parameters of Arabic flatbread to exploit the fortification of wheat flour with B complex vitamins. Results are expected to positively impact the output and economics of the fortification process. It is worth stressing the importance of this study, as it can be helpful material for the upcoming micronutrient survey conducted by FAO to assess the fortification process outcomes.
Detection of frozen-thawed beef, pork and chicken meatOriginal Paper
Filip Beňo, Eliška Václavíková, Filip Hruška, Nell Melisa Heráková, Rudolf Ševčík
Thawed meat is usually of lower quality and less expensive than chilled meat, which some dishonest may exploit by fraudulently marketing it as chilled. This study focused on methods for detecting and distinguishing frozen meat from chilled meat. The activity of the enzyme aconitase in the eluate was determined, and the mineral cations (Na, K, Mg) as well as the concentrations of organic acids (acetic, citric, and lactic) were analysed in chilled and thawed meat stored for 7, 14, and 150 days at −18 °C. After 150 days of storage, aconitase activity increased from 47.2 ± 7.2 U/L to 395.3 ± 59.2 U/L in pork, from 45.8 ± 11.5 U/L to 133.3 ± 31.8 U/L in beef, and from 17.2 ± 8.6 U/L to 143.6 ± 41.5 U/L in chicken. The mineral content decreased during storage in meat samples, especially Na and K cations (P < 0.05). The results for organic acids were less conclusive. Principal component analysis (PCA) of the data confirmed a clear separation between chilled and thawed meat for all species, with a high variability of nearly 72%.
Enhanced Pectin methylesterase Inactivation in Passion Fruit Juice by Ohmic HeatingOriginal Paper
NhuKhue Doan, ThiHuong Nguyen, NhatTam Le, MinhTuan Pham, QuocDat Lai
This study investigated the potential of Ohmic heating (OH) for the inactivation of pectin methylesterase (PME) in passion fruit juice. PME is a heat-resistant enzyme responsible for juice cloud loss and quality deterioration during storage; thus, it is commonly used as an indicator for pasteurization effectiveness. The juice samples were first heated from 20 to 70 °C, then maintained at 70 °C for 10 s, while being subjected to different electric field strengths (20–40 V/cm) and frequencies ranging from 50 to 10,000 Hz. The highest PME inactivation was observed at 60 Hz, with increased electric field strength further enhancing the inactivation effect. Based on these results, a frequency of 60 Hz and electric field strength of 30 V/cm were selected for further experiments. The effects of temperature (60–90 °C) and holding time (0–90 s) on PME inactivation during OH treatment were then evaluated and compared with conventional heating (CH). OH treatment at 90 °C for 70 s resulted in approximately 90% PME inactivation. Notably, OH achieved 10.2% greater PME inactivation than CH at equivalent thermal conditions, without promoting degradation of heat-sensitive components. These findings demonstrate the potential of OH as an effective and gentle pasteurization method for fruit juice processing.
Impact of Microencapsulation and Milk Matrix on L. acidophilus Survival in Yogurt-Based Ice Creams
Feray İnci MADEN, Prof.Dr. Salih ÖZDEMİR
This study evaluated the viability of Lactobacillus acidophilus ATCC 4356 in yogurt ice cream produced from cow and buffalo milk using both free and encapsulated probiotic forms, with or without inulin. Alginate-based microencapsulation was applied, and the samples were analyzed over a 60-day storage period. Ten different formulations were tested at four time points (days 1, 15, 30, and 60) for microbial counts and physico-chemical parameters. The highest L. acidophilus counts (5.91 and 5.97 log CFU/g) were recorded in buffalo milk-based samples containing encapsulated probiotics and inulin, while control samples made from cow milk showed the lowest TAMB (6.73 log CFU/g) and L. acidophilus (5.23 log CFU/g) counts. Encapsulation was found to significantly improve probiotic stability compared to free cells, especially in buffalo milk matrices. Yeast and mold counts remained below 2.00 log CFU/g after 30 days in most encapsulated formulations. Additionally, pH decreased and titratable acidity increased during storage. Ice cream samples with encapsulated probiotics exhibited longer melting resistance and higher viscosity values. These findings support the use of microencapsulation -particularly in buffalo milk- as an effective strategy to enhance probiotic viability and functional quality in frozen dairy systems.
Occurrence of Norovirus genogroup II in leafy greens in the region of Marrakech using a molecular methodOriginal Paper
Salma Berrouch, Nouhaila El Fellaki, Abdelkader Biary, Hibatallah Lachkar, Houda Rafi, Halima Rouane, Simeon Goita, Jamal Eddine Hafid
Leafy greens are significant vectors for enteric viruses, including human Noroviruses (HuNoV), a major cause of foodborne disease. These viruses can enter the agricultural environment via untreated wastewater or direct contamination. Although studies have investigated HuNoV in vegetables, few have been conducted in Morocco. This study aimed to detect HuNoV in leafy greens collected in the region of Marrakech region over over a fifteen-week period (March–June 2023). For this purpose, 112 samples (coriander, lettuce and parsley) were collected and analyzed using the NM ISO 15216-2: 2020 method with minor modifications, after validation. The method involved eluting viruses using an alkaline buffer, concentrating them through polyethylene glycol precipitation, and detecting viral RNA via real-time RT-PCR. Our results showed the variability of the sensitivity of the method adopted for HuNoV-GII detection, with lettuce showing 3/3 positive replicates (mean quantification cycle ± standard deviation of 26.42 ± 1.42) and coriander and parsley with 1 positive replicate /3. and enabled to assess the contamination of leafy greens, which was estimated at 0.89% (1/112). This study underscored the need to enhance detection methods to better assess the risks posed by noroviruses in leafy greens, with implications for human health.
Chemical composition, physical properties and sensory attributes of gluten-free pasta produced from acorn flourOriginal Paper
lassoued rabeb
The use of flours from the acorns of Quercus ilex and Quercus coccifera to produce gluten-free pasta was investigated in the current study. The latter evaluates the nutritional value, physical properties (minimum preparation time, water absorption index, cooking loss, and color), textural properties (hardness, firmness, and stickiness), and sensory attributes of cooked rice pasta enriched with different dosages of acorn flour (25 g/100 g and 50 g/100 g). The results demonstrated that pasta produced from Quercus acorn required the shortest cooking time, whereas pasta made from Quercus coccifera acorn exhibited the highest cooking losses. Pastes enriched with acorn displayed a more pronounced yellow color. The combination of 50% rice flour and 50% acorn flour in pasta formulations significantly reduced cooking losses and yielded acceptable scores across all sensory attributes, resulting in the highest overall quality.